ORCID Profile
0000-0002-6377-5132
Current Organisations
IT University of Copenhagen
,
Københavns Universitet
,
University of Melbourne
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Plant Cell and Molecular Biology | Plant Biology | Biochemistry and Cell Biology | Biochemistry and Cell Biology not elsewhere classified | Infectious Agents | Plant Biology not elsewhere classified | Structural Biology (incl. Macromolecular Modelling) | Global Change Biology | Cellular Interactions (incl. Adhesion, Matrix, Cell Wall) | Protein Trafficking | Animal Cell and Molecular Biology | Plant Physiology | Medical Parasitology | Nanobiotechnology | Cell Development, Proliferation and Death |
ANZSRC Socio-Economic Objective (SEO)
Plant Production and Plant Primary Products not elsewhere classified | Production of Biofuels (Biomass) | Climate and Climate Change not elsewhere classified | Expanding Knowledge in the Biological Sciences | Environmentally Sustainable Plant Production not elsewhere classified | Climate Change Adaptation Measures | Rice | Nervous System and Disorders | Biofuel (Biomass) Energy | Management of Water Consumption by Plant Production | Control of Pests, Diseases and Exotic Species not elsewhere classified | Health not elsewhere classified | Forestry not elsewhere classified | Infectious Diseases
Related Links
Publications
Transcriptional control of ROS homeostasis by KUODA1 regulates cell expansion during leaf development
Publisher: Springer Science and Business Media LLC
Date: 07-05-2014
DOI: 10.1038/NCOMMS4767
Abstract: The final size of an organism, or of single organs within an organism, depends on an intricate coordination of cell proliferation and cell expansion. Although organism size is of fundamental importance, the molecular and genetic mechanisms that control it remain far from understood. Here we identify a transcription factor, KUODA1 (KUA1), which specifically controls cell expansion during leaf development in Arabidopsis thaliana . We show that KUA1 expression is circadian regulated and depends on an intact clock. Furthermore, KUA1 directly represses the expression of a set of genes encoding for peroxidases that control reactive oxygen species (ROS) homeostasis in the apoplast. Disruption of KUA1 results in increased peroxidase activity and smaller leaf cells. Chemical or genetic interference with the ROS balance or peroxidase activity affects cell size in a manner consistent with the identified KUA1 function. Thus, KUA1 modulates leaf cell expansion and final organ size by controlling ROS homeostasis.
Cell wall integrity modulates Arabidopsis thaliana cell cycle gene expression in a cytokinin- and nitrate reductase-dependent manner
Publisher: The Company of Biologists
Date: 2018
DOI: 10.1242/DEV.166678
Abstract: During plant growth and defense, cell cycle activity needs to be coordinated with cell wall integrity. Little is known about how coordination is achieved. Here we investigated coordination in Arabidopsis thaliana seedlings by studying the impact of cell wall damage (CWD, caused by cellulose biosynthesis inhibition) on cytokinin homeostasis, cell cycle gene expression and shape in root tips. CWD inhibited cell cycle gene expression and increased transition zone cell width in an osmo-sensitive manner. These results were correlated with CWD-induced, osmo-sensitive changes in cytokinin homeostasis. Expression of CYTOKININ OXIDASE/DEHYDROGENASE2 and 3 (CKX2, CKX3), encoding cytokinin-degrading enzymes was induced by CWD and reduced by osmoticum treatment. In nitrate reductase1 nitrate reductase2 (nia1 nia2) seedlings, neither CKX2 and CKX3 transcript levels were increased nor cell cycle gene expression repressed by CWD. Moreover, established CWD-induced responses like jasmonic acid, salicylic acid and lignin production, were also absent, implying a central role of NIA1- and NIA2-mediated processes in regulation of CWD responses. These results suggest that CWD enhances cytokinin degradation rates through a NIA1 and NIA2-mediated process, subsequently attenuating cell cycle gene expression.
The elaborate route for UDP-arabinose delivery into the Golgi of plants
Publisher: Proceedings of the National Academy of Sciences
Date: 03-04-2017
Abstract: Nucleotide sugars, the activated sugar donors essential for processes such as cell wall biosynthesis and protein and lipid glycosylation are predominantly made in the cytosol. However, a highly erse range of glycosyltransferases that are located within the Golgi lumen, mediate the above-mentioned glycosylation reactions. Thus, transport of nucleotide sugars across the Golgi membrane into the lumen is crucial for growth and development of many species including microorganisms, plants, and humans. In this study, we identify and functionally characterize four UDP-arabinofuranose transporters from Arabidopsis that are responsible for the delivery of activated arabinose, a critical sugar of plant cell walls, glycoproteins, and signaling peptides.
Paramutation-Like Interaction of T-DNA Loci in Arabidopsis
Publisher: Public Library of Science (PLoS)
Date: 14-12-2012
Spatially distinct phytohormone responses of individualArabidopsis thalianaroot cells to infection and colonization byFusarium oxysporum
Publisher: Cold Spring Harbor Laboratory
Date: 20-12-2022
DOI: 10.1101/2022.12.20.521292
Abstract: Jasmonic acid (JA), ethylene (ET) and salicylic acid (SA) are the three major phytohormones coordinating a plant’s defense response to pathogenic attack. While JA and ET are assumed to primarily control the defense against necrotrophic pathogens, SA-induced defense responses target mainly biotrophic microbes, and can include drastic measures such as programmed cell death as part of the plant’s hypersensitive response (HR). Fusarium oxysporum is a hemibiotrophic fungal pathogen of several plant species, including many important food crops, and the model plant species Arabidopsis thaliana . Colonization of the plant’s root vascular tissue by the fungus eventually results in wilting and plant death. A general role for JA, ET and SA in combating infection and colonization of the plant by F. oxysporum has been demonstrated, but their distinct roles and modes of action have so far not been described. Here, using high resolution microscopy with fluorescent marker lines of A. thaliana roots infected with F. oxysporum we show that SA acts spatially separate from JA, in a distinct set of root cells immediately neighboring the fungal colonization site. There, SA induces HR to stop the spread of colonization. JA acts in a different, but also clearly defined set of cells, slightly removed from the colonization site, where it initiates a defense response to actively resist the invader. ET is activated in a stretch of cells that covers both, the cells with activated SA and JA signaling, and may be involved in creating these two distinct zones. These results show how the three phytohormones act together, but spatially and functionally separate from each other, to fight this hemibiotrophic pathogen. Such a high-resolution analysis to resolve the plant’s immune response to pathogenic infection on an in idual cell level and in intact tissue has so far been lacking. Colonization of the A . thaliana root tip by F . oxysporum strain Fo 5176 leads to immediate cell death of the colonized and surrounding tissue. As the colonization front progresses through the vasculature, the cell death front moves along with it through not only the vasculature, but also the surrounding tissues. WRKY70 positively regulates salicylic acid (SA) biosynthesis in cells immediately adjacent to the colonized tissue, inducing a hypersensitive response (HR), thereby killing off the cells deemed lost to the intruder, establishing the cell death front. Slightly further removed from the HR zone, WRKY11 induces jasmonate (JA) biosynthesis in cells of the vasculature to launch a defense response aimed at actively repelling the fungus.
A G protein-coupled receptor-like module regulates cellulose synthase secretion from the endomembrane system in Arabidopsis
Publisher: Elsevier BV
Date: 05-2021
Arabidopsis Heterotrimeric G-protein Regulates Cell Wall Defense and Resistance to Necrotrophic Fungi
Publisher: Elsevier BV
Date: 2012
DOI: 10.1093/MP/SSR082
Abstract: The Arabidopsis heterotrimeric G-protein controls defense responses to necrotrophic and vascular fungi. The agb1 mutant impaired in the Gβ subunit displays enhanced susceptibility to these pathogens. Gβ/AGB1 forms an obligate dimer with either one of the Arabidopsis Gγ subunits (γ1/AGG1 and γ2/AGG2). Accordingly, we now demonstrate that the agg1 agg2 double mutant is as susceptible as agb1 plants to the necrotrophic fungus Plectosphaerella cucumerina. To elucidate the molecular basis of heterotrimeric G-protein-mediated resistance, we performed a comparative transcriptomic analysis of agb1-1 mutant and wild-type plants upon inoculation with P. cucumerina. This analysis, together with metabolomic studies, demonstrated that G-protein-mediated resistance was independent of defensive pathways required for resistance to necrotrophic fungi, such as the salicylic acid, jasmonic acid, ethylene, abscisic acid, and tryptophan-derived metabolites signaling, as these pathways were not impaired in agb1 and agg1 agg2 mutants. Notably, many mis-regulated genes in agb1 plants were related with cell wall functions, which was also the case in agg1 agg2 mutant. Biochemical analyses and Fourier Transform InfraRed (FTIR) spectroscopy of cell walls from G-protein mutants revealed that the xylose content was lower in agb1 and agg1 agg2 mutants than in wild-type plants, and that mutant walls had similar FTIR spectratypes, which differed from that of wild-type plants. The data presented here suggest a canonical functionality of the Gβ and Gγ1/γ2 subunits in the control of Arabidopsis immune responses and the regulation of cell wall composition.
Plant cell shape: Modulators and measurements
Publisher: Frontiers Media SA
Date: 2013
Three AtCesA6‐like members enhance biomass production by distinctively promoting cell growth in Arabidopsis
Publisher: Wiley
Date: 23-10-2017
DOI: 10.1111/PBI.12842
Feeding the Walls: How Does Nutrient Availability Regulate Cell Wall Composition?
Publisher: MDPI AG
Date: 10-09-2018
DOI: 10.3390/IJMS19092691
Abstract: Nutrients are critical for plants to grow and develop, and nutrient depletion severely affects crop yield. In order to optimize nutrient acquisition, plants adapt their growth and root architecture. Changes in growth are determined by modifications in the cell walls surrounding every plant cell. The plant cell wall, which is largely composed of complex polysaccharides, is essential for plants to attain their shape and to protect cells against the environment. Within the cell wall, cellulose strands form microfibrils that act as a framework for other wall components, including hemicelluloses, pectins, proteins, and, in some cases, callose, lignin, and suberin. Cell wall composition varies, depending on cell and tissue type. It is governed by synthesis, deposition and remodeling of wall components, and determines the physical and structural properties of the cell wall. How nutrient status affects cell wall synthesis and organization, and thus plant growth and morphology, remains poorly understood. In this review, we aim to summarize and synthesize research on the adaptation of root cell walls in response to nutrient availability and the potential role of cell walls in nutrient sensing.
Overexpression of the Ca2+‐binding protein calreticulin in the endoplasmic reticulum improves growth of tobacco cell suspensions (Nicotiana tabacum) in high‐Ca2+ medium
Publisher: Wiley
Date: 02-12-2004
Analyzing gene coexpression data by an evolutionary model.
Publisher: IMPERIAL COLLEGE PRESS
Date: 07-2010
Cellulose Synthesis and Cell Expansion Are Regulated by Different Mechanisms in Growing Arabidopsis Hypocotyls
Publisher: Oxford University Press (OUP)
Date: 26-05-2017
DOI: 10.1105/TPC.16.00782
Ectopic expression of OsJAZ6, which interacts with OsJAZ1, alters JA signaling and spikelet development in rice
Publisher: Wiley
Date: 07-10-2021
DOI: 10.1111/TPJ.15496
Abstract: Jasmonates (JAs) are key phytohormones that regulate plant responses and development. JASMONATE‐ZIM DOMAIN (JAZ) proteins safeguard JA signaling by repressing JA‐responsive gene expression in the absence of JA. However, the interaction and cooperative roles of JAZ repressors remain unclear during plant development. Here, we found that OsJAZ6 interacts with OsJAZ1 depending on a single amino acid in the so‐called ZIM domain of OsJAZ6 in rice JA signaling transduction and JA‐regulated rice spikelet development. In vivo protein distribution analysis revealed that the OsJAZ6 content is efficiently regulated during spikelet development, and biochemical and genetic evidence showed that OsJAZ6 is more sensitive to JA‐mediated degradation than OsJAZ1. Through over‐ and mis‐expression experiments, we further showed that the protein stability and levels of OsJAZ6 orchestrate the output of JA signaling during rice spikelet development. A possible mechanism, which outlines how OsJAZ repressors interact and function synergistically in specifying JA signaling output through degradation titration, is also discussed.
The impact of abiotic factors on cellulose synthesis
Publisher: Oxford University Press (OUP)
Date: 09-11-2015
DOI: 10.1093/JXB/ERV488
Abstract: As sessile organisms, plants require mechanisms to sense and respond to changes in their environment, including both biotic and abiotic factors. One of the most common plant adaptations to environmental changes is differential regulation of growth, which results in growth either away from adverse conditions or towards more favorable conditions. As cell walls shape plant growth, this differential growth response must be accompanied by alterations to the plant cell wall. Here, we review the impact of four abiotic factors (osmotic conditions, ionic stress, light, and temperature) on the synthesis of cellulose, an important component of the plant cell wall. Understanding how different abiotic factors influence cellulose production and addressing key questions that remain in this field can provide crucial information to cope with the need for increased crop production under the mounting pressures of a growing world population and global climate change.
Grass-Specific EPAD1 Is Essential for Pollen Exine Patterning in Rice
Publisher: Oxford University Press (OUP)
Date: 22-10-2020
DOI: 10.1105/TPC.20.00551
Live-cell imaging of the cytoskeleton in elongating cotton fibres.
Publisher: Springer Science and Business Media LLC
Date: 30-04-2019
DOI: 10.1038/S41477-019-0418-8
Abstract: Cotton (Gossypium hirsutum) fibres consist of single cells that grow in a highly polarized manner, assumed to be controlled by the cytoskeleton
Identification of genes required for cellulose synthesis by regression analysis of public microarray data sets
Publisher: Proceedings of the National Academy of Sciences
Date: 02-06-2005
Abstract: Coexpression patterns of gene expression across many microarray data sets may reveal networks of genes involved in linked processes. To identify factors involved in cellulose biosynthesis, we used a regression method to analyze 408 publicly available Affymetrix Arabidopsis microarrays. Expression of genes previously implicated in cellulose synthesis, as well as several uncharacterized genes, was highly coregulated with expression of cellulose synthase (CESA) genes. Four candidate genes, which were coexpressed with CESA genes implicated in secondary cell wall synthesis, were investigated by mutant analysis. Two mutants exhibited irregular xylem phenotypes similar to those observed in mutants with defects in secondary cellulose synthesis and were designated irx8 and irx13 . Thus, the general approach developed here is useful for identification of elements of multicomponent processes.
An Update on Xylan Synthesis
Publisher: Elsevier BV
Date: 07-2012
DOI: 10.1093/MP/SSS049
Quantification of Cytoskeletal Dynamics in Time‐Lapse Recordings
Publisher: Wiley
Date: 15-05-2019
DOI: 10.1002/CPPB.20091
Abstract: The cytoskeleton is key to many essential processes in a plant cell, e.g., growth, ision, and defense. Contrary to what "skeleton" implies, the cytoskeleton is highly dynamic, and is able to re-organize itself continuously. The advent of live-cell microscopy and the development of genetically encoded fluorophores enabled detailed observation of the organization and dynamics of the cytoskeleton. Despite the biological importance of the cytoskeletal dynamics, quantitative analyses remain laborious endeavors that only a handful of research teams regularly conduct. With this protocol, we provide a standardized step-by-step guide to analyze the dynamics of microtubules. We provide ex le data and code for post-processing in Fiji that enables researchers to modify and adapt the routine to their needs. More such tools are needed to quantitatively assess the cytoskeleton and thus to better understand cell biology. © 2019 by John Wiley & Sons, Inc.
Effects of natural starch-phosphate monoester content on the multi-scale structures of potato starches
Publisher: Elsevier BV
Date: 06-2023
The OsJAZ1 degron modulates jasmonate signaling sensitivity during rice development.
Publisher: The Company of Biologists
Date: 2019
DOI: 10.1242/DEV.173419
Abstract: Jasmonates (JAs) are crucial to the coordination of plant stress responses and development. JA signaling depends on JASMONATE-ZIM DOMAIN (JAZ) proteins that are destroyed by the SCF
Development and application of a suite of polysaccharide-degrading enzymes for analyzing plant cell walls
Publisher: Proceedings of the National Academy of Sciences
Date: 25-07-2006
Abstract: To facilitate analysis of plant cell wall polysaccharide structure and composition, we cloned 74 genes encoding polysaccharide-degrading enzymes from Aspergillus nidulans , Aspergillus fumigatus , and Neurospora crassa and expressed the genes as secreted proteins with C-terminal Myc and 6× His tags. Most of the recombinant enzymes were active in enzyme assays, and optima for pH and temperature were established. A subset of the enzymes was used to fragment polysaccharides from the irregular xylem 9 ( irx9 ) mutant of Arabidopsis . The analysis revealed a decrease in the abundance of xylan in the mutant, indicating that the IRX9 gene, which encodes a putative family 43 glycosyltransferase, is required for xylan synthesis.
Building a plant cell wall at a glance
Publisher: The Company of Biologists
Date: 15-01-2018
DOI: 10.1242/JCS.207373
Abstract: Plant cells are surrounded by a strong polysaccharide-rich cell wall that aids in determining the overall form, growth and development of the plant body. Indeed, the unique shapes of the 40-odd cell types in plants are determined by their walls, as removal of the cell wall results in spherical protoplasts that are amorphic. Hence, assembly and remodeling of the wall is essential in plant development. Most plant cell walls are composed of a framework of cellulose microfibrils that are cross-linked to each other by heteropolysaccharides. The cell walls are highly dynamic and adapt to the changing requirements of the plant during growth. However, despite the importance of plant cell walls for plant growth and for applications that we use in our daily life such as food, feed and fuel, comparatively little is known about how they are synthesized and modified. In this Cell Science at a Glance article and accompanying poster, we aim to illustrate the underpinning cell biology of the synthesis of wall carbohydrates, and their incorporation into the wall, in the model plant Arabidopsis.
Differential Regulation of Carbon Partitioning by the Central Growth Regulator Target of Rapamycin (TOR)
Publisher: Elsevier BV
Date: 11-2013
DOI: 10.1093/MP/SST094
A Mechanism for Sustained Cellulose Synthesis during Salt Stress
Publisher: Elsevier BV
Date: 09-2015
DOI: 10.1016/J.CELL.2015.08.028
Abstract: Abiotic stress, such as salinity, drought, and cold, causes detrimental yield losses for all major plant crop species. Understanding mechanisms that improve plants' ability to produce biomass, which largely is constituted by the plant cell wall, is therefore of upmost importance for agricultural activities. Cellulose is a principal component of the cell wall and is synthesized by microtubule-guided cellulose synthase enzymes at the plasma membrane. Here, we identified two components of the cellulose synthase complex, which we call companion of cellulose synthase (CC) proteins. The cytoplasmic tails of these membrane proteins bind to microtubules and promote microtubule dynamics. This activity supports microtubule organization, cellulose synthase localization at the plasma membrane, and renders seedlings less sensitive to stress. Our findings offer a mechanistic model for how two molecular components, the CC proteins, sustain microtubule organization and cellulose synthase localization and thus aid plant biomass production during salt stress. VIDEO ABSTRACT.
pGG-PIP: A GreenGate (GG) entry vector collection with Plant Immune system Promoters (PIP)
Publisher: Cold Spring Harbor Laboratory
Date: 20-12-2022
DOI: 10.1101/2022.12.20.521163
Abstract: The regulatory sequences controlling the expression of a gene (i.e., the promoter) are essential to properly understand a gene’s function. From their use in mutant complementation assays, to studying their responsiveness to different stimuli via transcriptional reporter lines or using them as proxy for the activation of certain pathways, assays using promoter sequences are valuable tools for insight into the genetic architecture underlying plant life. The GreenGate (GG) system is a plant-specific variant of the Golden Gate assembly method, a modular cloning system that allows the hierarchical assembly of in idual donor DNA fragments into one expression clone via a single reaction step. Here, we present a collection of 75 GG entry vectors carrying putative regulatory sequences for Arabidopsis thaliana genes involved in many different pathways of the plant immune system, designated Plant Immune system Promoters (PIP). This pGG-PIP entry vector set enables the rapid assembly of expression vectors to be used for transcriptional reporters of plant immune system components, mutant complementation assays when coupled with coding sequences, mis-expression experiments for genes of interest, or the targeted use of CRISPR/Cas9 genome editing. We used pGG-PIP vectors to create fluorescent transcriptional reporters in A . thaliana and demonstrated the potential of these reporters to image the responsiveness of specific plant immunity genes to infection and colonization by the fungal pathogen Fusarium oxysporum . Using the PLANT ELICITOR PEPTIDE (PEP) pathway as an ex le, we show that several components of this pathway are locally activated in response to colonization by the fungus.
Cellulose synthesis: a complex complex
Publisher: Elsevier BV
Date: 06-2008
DOI: 10.1016/J.PBI.2008.03.007
Abstract: Cellulose is the world's most abundant biopolymer and a key structural component of the plant cell wall. Cellulose is comprised of hydrogen-bonded beta-1,4-linked glucan chains that are synthesized at the plasma membrane by large cellulose synthase (CESA) complexes. Recent advances in visualization of fluorescently labelled complexes have facilitated exploration of regulatory modes of cellulose production. For ex le, several herbicides, such as isoxaben and 2,6-dichlorobenzonitrile that inhibit cellulose production appear to affect different aspects of synthesis. Dual-labelling of cytoskeletal components and CESAs has revealed dynamic feedback regulation between cellulose synthesis and microtubule orientation and organization. In addition, fluorescently tagged CESA2 subunits may substitute for another subunit, CESA6, which suggests both plasticity and specificity for one of the components of the CESA complex.
At the border: the plasma membrane-cell wall continuum
Publisher: Oxford University Press (OUP)
Date: 19-02-2015
DOI: 10.1093/JXB/ERV019
Abstract: Plant cells rely on their cell walls for directed growth and environmental adaptation. Synthesis and remodelling of the cell walls are membrane-related processes. During cell growth and exposure to external stimuli, there is a constant exchange of lipids, proteins, and other cell wall components between the cytosol and the plasma membrane/apoplast. This exchange of material and the localization of cell wall proteins at certain spots in the plasma membrane seem to rely on a particular membrane composition. In addition, sensors at the plasma membrane detect changes in the cell wall architecture, and activate cytoplasmic signalling schemes and ultimately cell wall remodelling. The apoplastic polysaccharide matrix is, on the other hand, crucial for preventing proteins diffusing uncontrollably in the membrane. Therefore, the cell wall-plasma membrane link is essential for plant development and responses to external stimuli. This review focuses on the relationship between the cell wall and plasma membrane, and its importance for plant tissue organization.
A Transcriptional and Metabolic Framework for Secondary Wall Formation in Arabidopsis
Publisher: Oxford University Press (OUP)
Date: 26-08-2016
DOI: 10.1104/PP.16.01100
Abstract: Plant cell walls are essential for plant growth and development. The cell walls are traditionally ided into primary walls, which surround growing cells, and secondary walls, which provide structural support to certain cell types and promote their functions. While much information is available about the enzymes and components that contribute to the production of these two types of walls, much less is known about the transition from primary to secondary wall synthesis. To address this question, we made use of a transcription factor system in Arabidopsis (Arabidopsis thaliana) in which an overexpressed master secondary wall-inducing transcription factor, VASCULAR-RELATED NAC DOMAIN PROTEIN7, can be redirected into the nucleus by the addition of dexamethasone. We established the time frame during which primary wall synthesis changed into secondary wall production in dexamethasone-treated seedlings and measured transcript and metabolite abundance at eight time points after induction. Using cluster- and network-based analyses, we integrated the data sets to explore coordination between transcripts, metabolites, and the combination of the two across the time points. We provide the raw data as well as a range of network-based analyses. These data reveal links between hormone signaling and metabolic processes during the formation of secondary walls and provide a framework toward a deeper understanding of how primary walls transition into secondary walls.
Co‐expression tools for plant biology: opportunities for hypothesis generation and caveats
Publisher: Wiley
Date: 05-11-2009
DOI: 10.1111/J.1365-3040.2009.02040.X
Abstract: Gene co-expression analysis has emerged in the past 5 years as a powerful tool for gene function prediction. In essence, co-expression analysis asks the question 'what are the genes that are co-expressed, that is, those that show similar expression profiles across many experiments, with my gene of interest?'. Genes that are highly co-expressed may be involved in the biological process or processes of the query gene. This review describes the tools that are available for performing such analyses, how each of these perform, and also discusses statistical issues including how normalization of gene expression data can influence co-expression results, calculation of co-expression scores and P values, and the influence of data sets used for co-expression analysis. Finally, ex les from the literature will be presented, wherein co-expression has been used to corroborate and discover various aspects of plant biology.
V-ATPase activity in the TGN/EE is required for exocytosis and recycling in Arabidopsis
Publisher: Springer Science and Business Media LLC
Date: 06-07-2015
The TOR complex controls ATP levels to regulate actin cytoskeleton dynamics in Arabidopsis
Publisher: Proceedings of the National Academy of Sciences
Date: 12-09-2022
Abstract: Energy is essential for all cellular functions in a living organism. How cells coordinate their physiological processes with energy status and availability is thus an important question. The turnover of actin cytoskeleton between its monomeric and filamentous forms is a major energy drain in eukaryotic cells. However, how actin dynamics are regulated by ATP levels remain largely unknown in plant cells. Here, we observed that seedlings with impaired functions of target of rapamycin complex 1 (TORC1), either by mutation of the key component, RAPTOR1B , or inhibition of TOR activity by specific inhibitors, displayed reduced sensitivity to actin cytoskeleton disruptors compared to their controls. Consistently, actin filament dynamics, but not organization, were suppressed in TORC1-impaired cells. Subcellular localization analysis and quantification of ATP concentration demonstrated that RAPTOR1B localized at cytoplasm and mitochondria and that ATP levels were significantly reduced in TORC1-impaired plants. Further pharmacologic experiments showed that the inhibition of mitochondrial functions led to phenotypes mimicking those observed in raptor1b mutants at the level of both plant growth and actin dynamics. Exogenous feeding of adenine could partially restore ATP levels and actin dynamics in TORC1-deficient plants. Thus, these data support an important role for TORC1 in coordinating ATP homeostasis and actin dynamics in plant cells.
The ER and Cell Calcium
Publisher: Springer Berlin Heidelberg
Date: 2006
DOI: 10.1007/7089_062
GhMYB7 promotes secondary wall cellulose deposition in cotton fibres by regulating GhCesA gene expression through three distinct cis‐elements
Publisher: Wiley
Date: 04-08-2021
DOI: 10.1111/NPH.17612
Abstract: Cotton fibre is the most important source for natural textiles. The secondary cell walls (SCWs) of mature cotton fibres contain the highest proportion of cellulose content ( 90%) in any plant. The onset and progression of SCW cellulose synthesis need to be tightly controlled to balance fibre elongation and cell wall deposition. However, regulatory mechanisms that control cellulose synthesis during cotton fibre growth remain elusive. Here, we conducted genetic and functional analyses demonstrating that the R2R3‐MYB GhMYB7 controls cotton fibre cellulose synthesis. Overexpression of GhMYB7 in cotton sped up SCW cellulose biosynthesis in fibre cells, and led to shorter fibres with thicker walls. By contrast, RNA interference (RNAi) silencing of GhMYB7 delayed fibre SCW cellulose synthesis and resulted in elongated fibres with thinner walls. Furthermore, we demonstrated that GhMYB7 regulated cotton fibre SCW cellulose synthases by directly binding to three distinct cis ‐elements in the respective GhCesA4 , GhCesA7 and GhCesA8 promoters. We found that this regulatory mechanism of cellulose synthesis was ‘hi‐jacked’ also by other GhMYBs. Together, our findings uncover a hitherto‐unknown mechanism that cotton fibre employs to regulate SCW cellulose synthesis. Our results also provide a strategy for genetic improvement of SCW thickness of cotton fibre.
Patterning and Lifetime of Plasma Membrane-Localized Cellulose Synthase Is Dependent on Actin Organization in Arabidopsis Interphase Cells
Publisher: Oxford University Press (OUP)
Date: 19-04-2013
Abstract: The actin and microtubule cytoskeletons regulate cell shape across phyla, from bacteria to metazoans. In organisms with cell walls, the wall acts as a primary constraint of shape, and generation of specific cell shape depends on cytoskeletal organization for wall deposition and/or cell expansion. In higher plants, cortical microtubules help to organize cell wall construction by positioning the delivery of cellulose synthase (CesA) complexes and guiding their trajectories to orient newly synthesized cellulose microfibrils. The actin cytoskeleton is required for normal distribution of CesAs to the plasma membrane, but more specific roles for actin in cell wall assembly and organization remain largely elusive. We show that the actin cytoskeleton functions to regulate the CesA delivery rate to, and lifetime of CesAs at, the plasma membrane, which affects cellulose production. Furthermore, quantitative image analyses revealed that actin organization affects CesA tracking behavior at the plasma membrane and that small CesA compartments were associated with the actin cytoskeleton. By contrast, localized insertion of CesAs adjacent to cortical microtubules was not affected by the actin organization. Hence, both actin and microtubule cytoskeletons play important roles in regulating CesA trafficking, cellulose deposition, and organization of cell wall biogenesis.
The Toolbox to Study Protein–Protein Interactions in Plants
Publisher: Informa UK Limited
Date: 04-07-2018
Subacromial decompression surgery for adults with shoulder pain: a systematic review with meta-analysis.
Publisher: BMJ
Date: 15-01-2020
DOI: 10.1136/BJSPORTS-2018-100486
Abstract: To determine the benefits and harms of subacromial decompression surgery in adult patients with subacromial pain syndrome lasting for more than 3 months. Systematic review with meta-analysis. Pain, physical function and health-related quality of life. Systematic searches for benefits and harms were conducted to 23 July 2018 in MEDLINE, Embase, PubMed, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Cumulative Index to Nursing and Allied Health Literature, Physiotherapy Evidence Database, ClinicalTrials.gov, WHO International Clinical Trials Registry Platform, Database of Abstracts of Reviews of Effects, and Health Technology Assessment. Randomised controlled trials comparing subacromial decompression surgery for subacromial pain syndrome with any other treatment(s). For harms, we included prospective cohort studies. Two reviewers independently determined eligibility, extracted the data and assessed the risk of bias of eligible studies. Thirty patients seeking primary or outpatient care for subacromial pain syndrome and a parallel guideline committee ( There was high certainty evidence of no additional benefit of subacromial decompression surgery over placebo surgery in reducing pain at 1 year following surgery (mean difference [MD] -0.26, 95% CI -0.84 to 0.33, minimally important difference [MID] 1.5) or improving physical function at 1-2 years (MD 2.8, 95% CI -1.4 to 6.9, MID 8.3). There was moderate certainty evidence for no additional benefit of subacromial decompression surgery on health-related quality of life at 1 year (MD -0.03 points, 95% CI -0.11 to 0.06, MID 0.07). There was moderate certainty evidence for six serious harms per 1000 (95% CI 5 to 7) patients undergoing subacromial decompression. Subacromial decompression surgery provided no important benefit compared with placebo surgery or exercise therapy, and probably carries a small risk of serious harms. CRD42018086862.
The Rice Actin-Binding Protein RMD Regulates Light-Dependent Shoot Gravitropism
Publisher: Oxford University Press (OUP)
Date: 15-08-2019
DOI: 10.1104/PP.19.00497
The TPLATE Adaptor Complex Drives Clathrin-Mediated Endocytosis in Plants
Publisher: Elsevier BV
Date: 02-2014
DOI: 10.1016/J.CELL.2014.01.039
Abstract: Clathrin-mediated endocytosis is the major mechanism for eukaryotic plasma membrane-based proteome turn-over. In plants, clathrin-mediated endocytosis is essential for physiology and development, but the identification and organization of the machinery operating this process remains largely obscure. Here, we identified an eight-core-component protein complex, the TPLATE complex, essential for plant growth via its role as major adaptor module for clathrin-mediated endocytosis. This complex consists of evolutionarily unique proteins that associate closely with core endocytic elements. The TPLATE complex is recruited as dynamic foci at the plasma membrane preceding recruitment of adaptor protein complex 2, clathrin, and dynamin-related proteins. Reduced function of different complex components severely impaired internalization of assorted endocytic cargoes, demonstrating its pivotal role in clathrin-mediated endocytosis. Taken together, the TPLATE complex is an early endocytic module representing a unique evolutionary plant adaptation of the canonical eukaryotic pathway for clathrin-mediated endocytosis.
ETHYLENE RESPONSE FACTOR 34 promotes secondary cell wall thickening and strength of rice peduncles
Publisher: Oxford University Press (OUP)
Date: 09-2022
Abstract: Cellulose and lignin are critical cell wall components for plant morphogenesis and adaptation to environmental conditions. The cytoskeleton supports cell wall deposition, but much of the underpinning regulatory components remain unknown. Here, we show that an APETALA2/ETHYLENE RESPONSE FACTOR (ERF) family transcription factor, OsERF34, directly promotes the expression of the actin- and microtubule-binding protein Rice Morphology Determinant (RMD) in rice (Oryza sativa) peduncles. OsERF34 and RMD are highly expressed in sclerenchymatous peduncle cells that are fortified by thick secondary cell walls (SCWs) that provide mechanical peduncle strength. erf34 and rmd-1 mutants contained lower cellulose and lignin contents and thinner SCWs, while ERF34 over-expressing (OE) lines maintained high cellulose and lignin content with thicker SCWs. These characteristics impacted peduncle mechanical strength, that is, reduced strength in erf34 and rmd-1 and increased strength of ERF34 OE plants. Taken together, our results demonstrate that the OsERF34-RMD cascade positively regulates SCW synthesis and mechanical strength in rice peduncles, which is important for yield, and provide a potential guide for improved peduncle breeding efforts in rice.
Balanced callose and cellulose biosynthesis in Arabidopsis quorum-sensing signaling and pattern-triggered immunity
Publisher: Oxford University Press (OUP)
Date: 30-08-2023
Abstract: The plant cell wall (CW) is one of the most important physical barriers phytopathogens must conquer to invade their hosts. This barrier is a dynamic structure that responds to pathogen infection through a complex network of immune receptors, together with CW-synthesizing and CW-degrading enzymes. Callose deposition in the primary CW is a well-known physical response to pathogen infection. Notably, callose and cellulose biosynthesis share an initial substrate, UDP-glucose, which is the main load-bearing component of the CW. However, how these two critical biosynthetic processes are balanced during plant-pathogen interactions remains unclear. Here, using two different pathogen-derived molecules, bacterial flagellin (flg22) and the diffusible signal factor (DSF) produced by Xanthomonas c estris pv. c estris, we show a negative correlation between cellulose and callose biosynthesis in Arabidopsis (Arabidopsis thaliana). By quantifying the abundance of callose and cellulose under DSF or flg22 elicitation and characterizing the dynamics of the enzymes involved in the biosynthesis and degradation of these two polymers, we show that the balance of these two CW components is mediated by the activity of a β-1,3-glucanase (BG2). Our data demonstrate balanced cellulose and callose biosynthesis during plant immune responses.
The Plasma Membrane and the Cell Wall
Publisher: Springer Berlin Heidelberg
Date: 04-09-2010
Phytohormones and the cell wall in Arabidopsis during seedling growth
Publisher: Elsevier BV
Date: 05-2010
DOI: 10.1016/J.TPLANTS.2010.03.002
Abstract: Cell wall biosynthesis, and remodelling, is a prerequisite for plant growth from cell plate formation in iding cells, to the strengthening of the vascular tissue by secondary cell wall deposits. Many plant hormones are also essential for plant growth and development, such as auxin that controls cell proliferation and differentiation. Direct links between hormone actions and changes in cell wall structure have therefore been assumed, and long sought. While many studies during recent decades have supported such relationships, the vast majority have been inferred through indirect means. In an era that embraces cell-wall-related products, including cellulosic biofuels, we attempt to give an overview of phytohormone-mediated cell expansion, and cell wall biosynthesis in Arabidopsis during seedling growth.
Regulation of Cell Wall Formation by Membrane Traffic
Publisher: Wiley
Date: 05-09-2014
Quantitative analyses of the plant cytoskeleton reveal underlying organizational principles
Publisher: The Royal Society
Date: 06-08-2014
Abstract: The actin and microtubule (MT) cytoskeletons are vital structures for cell growth and development across all species. While in idual molecular mechanisms underpinning actin and MT dynamics have been intensively studied, principles that govern the cytoskeleton organization remain largely unexplored. Here, we captured biologically relevant characteristics of the plant cytoskeleton through a network-driven imaging-based approach allowing us to quantitatively assess dynamic features of the cytoskeleton. By introducing suitable null models, we demonstrate that the plant cytoskeletal networks exhibit properties required for efficient transport, namely, short average path lengths and high robustness. We further show that these advantageous features are maintained during temporal cytoskeletal rearrangements. Interestingly, man-made transportation networks exhibit similar properties, suggesting general laws of network organization supporting erse transport processes. The proposed network-driven analysis can be readily used to identify organizational principles of cytoskeletons in other organisms.
Cellulose synthesis during cell plate assembly
Publisher: Wiley
Date: 19-06-2018
DOI: 10.1111/PPL.12703
Abstract: The plant cell wall surrounds and protects the cells. To ide, plant cells must synthesize a new cell wall to separate the two daughter cells. The cell plate is a transient polysaccharide-based compartment that grows between daughter cells and gives rise to the new cell wall. Cellulose constitutes a key component of the cell wall, and mutants with defects in cellulose synthesis commonly share phenotypes with cytokinesis-defective mutants. However, despite the importance of cellulose in the cell plate and the daughter cell wall, many open questions remain regarding the timing and regulation of cellulose synthesis during cell ision. These questions represent a critical gap in our knowledge of cell plate assembly, cell ision and growth. Here, we review what is known about cellulose synthesis at the cell plate and in the newly formed cross-wall and pose key questions about the molecular mechanisms that govern these processes. We further provide an outlook discussing outstanding questions and possible future directions for this field of research.
Inhibition of TOR Represses Nutrient Consumption, Which Improves Greening after Extended Periods of Etiolation
Publisher: Oxford University Press (OUP)
Date: 26-07-2018
DOI: 10.1104/PP.18.00684
Dissection of Plant Cell Walls by High‐Throughput Methods
Publisher: Wiley
Date: 23-11-2010
The effects of different types of high-amylose maize starches on viscosity and digestion of acidified milk gels
Publisher: Elsevier BV
Date: 03-2023
DOI: 10.1016/J.FOODCHEM.2022.134525
Abstract: High-amylose maize starch (HAMS) can provide dietary fiber to foods. In this study, we investigated the effects of three HAMSs (Gelose 50, Hylon VII, and NAFU50) on the functionality of casein (CA) and/or whey protein (WP) networks in acidified milk gels using normal maize starch (NMS) as a control thickener. When compared with NMS, HAMSs performed better in increasing the resistant starch content (RS), storage modulus, loss modulus, and complex viscosity of all the milk gels. The results are attributed to the retention of the starch granular integrity of HAMSs during the preparation of the milk gels, as observed by microscopy. HylonVII exhibited the highest RS and viscosity in all milk gel systems, especially in WP gels (71.8 % RS and >3000 Pa.s at 1 Hz viscosity). Our data provide support for the potential of using HAMS to develop healthier yogurt products using functional thickeners from natural sources.
Transcriptional Coordination of the Metabolic Network in Arabidopsis
Publisher: Oxford University Press (OUP)
Date: 18-08-2006
Abstract: Patterns of coexpression can reveal networks of functionally related genes and provide deeper understanding of processes requiring multiple gene products. We performed an analysis of coexpression networks for 1,330 genes from the AraCyc database of metabolic pathways in Arabidopsis (Arabidopsis thaliana). We found that genes associated with the same metabolic pathway are, on average, more highly coexpressed than genes from different pathways. Positively coexpressed genes within the same pathway tend to cluster close together in the pathway structure, while negatively correlated genes typically occupy more distant positions. The distribution of coexpression links per gene is highly skewed, with a small but significant number of genes having numerous coexpression partners but most having fewer than 10. Genes with multiple connections (hubs) tend to be single-copy genes, while genes with multiple paralogs are coexpressed with fewer genes, on average, than single-copy genes, suggesting that the network expands through gene duplication, followed by weakening of coexpression links involving duplicate nodes. Using a network-analysis algorithm based on coexpression with multiple pathway members (pathway-level coexpression), we identified and prioritized novel candidate pathway members, regulators, and cross pathway transcriptional control points for over 140 metabolic pathways. To facilitate exploration and analysis of the results, we provide a Web site (t_coexpress/analysis/web) listing analyzed pathways with links to regression and pathway-level coexpression results. These methods and results will aid in the prioritization of candidates for genetic analysis of metabolism in plants and contribute to the improvement of functional annotation of the Arabidopsis genome.
Salt with a sweet tooth: galactan synthesis impacts salt tolerance in Arabidopsis
Publisher: Elsevier BV
Date: 03-2021
Downregulation of the δ-Subunit Reduces Mitochondrial ATP Synthase Levels, Alters Respiration, and Restricts Growth and Gametophyte Development in Arabidopsis
Publisher: Oxford University Press (OUP)
Date: 07-2012
The FRIABLE1 gene product affects cell adhesion in arabidopsis
Publisher: Public Library of Science (PLoS)
Date: 14-08-2012
Cellulose synthesis across kingdoms
Publisher: Elsevier BV
Date: 04-2023
Identification of a cellulose synthase-associated protein required for cellulose biosynthesis
Publisher: Proceedings of the National Academy of Sciences
Date: 07-2010
Abstract: Cellulose synthase-interactive protein 1 (CSI1) was identified in a two-hybrid screen for proteins that interact with cellulose synthase (CESA) isoforms involved in primary plant cell wall synthesis. CSI1 encodes a 2,150-amino acid protein that contains 10 predicted Armadillo repeats and a C2 domain. Mutations in CSI1 cause defective cell elongation in hypocotyls and roots and reduce cellulose content. CSI1 is associated with CESA complexes, and csi1 mutants affect the distribution and movement of CESA complexes in the plasma membrane.
Root hair growth: It's a one way street
Publisher: Faculty Opinions Ltd
Date: 03-02-2015
DOI: 10.12703/P7-23
BRASSINOSTEROID INSENSITIVE2 negatively regulates cellulose synthesis in Arabidopsis by phosphorylating cellulose synthase 1
Publisher: Proceedings of the National Academy of Sciences
Date: 13-03-2017
Abstract: Cellulose is the most abundant biopolymer on Earth and is a critical component for plants to grow and develop. Cellulose is synthesized by large cellulose synthase complexes containing multiple cellulose synthase A (CESA) subunits however, how cellulose synthesis is regulated remains unclear. In this study, we identify BRASSINOSTEROID INSENSITIVE2 (BIN2) as a protein kinase that directly phosphorylates Arabidopsis CESA1 and further demonstrate that this phosphorylation event negatively regulates CESA activity, and thus cellulose biosynthesis, in Arabidopsis . Therefore, this study provides a clear link between cell wall biosynthesis and hormonal signal transduction pathways that regulate plant growth and development.
Investigation of CRISPR/Cas9-induced SD1 rice mutants highlights the importance of molecular characterization in plant molecular breeding
Publisher: Elsevier BV
Date: 05-2020
Differentiation of Tracheary Elements in Sugarcane Suspension Cells Involves Changes in Secondary Wall Deposition and Extensive Transcriptional Reprogramming
Publisher: Frontiers Media SA
Date: 18-12-2020
Abstract: Plant lignocellulosic biomass, mostly composed of polysaccharide-rich secondary cell walls (SCWs), provides fermentable sugars that may be used to produce biofuels and biomaterials. However, the complex chemical composition and physical structure of SCWs hinder efficient processing of plant biomass. Understanding the molecular mechanisms underlying SCW deposition is, thus, essential to optimize bioenergy feedstocks. Here, we establish a xylogenic culture as a model system to study SCW deposition in sugarcane the first of its kind in a C4 grass species. We used auxin and brassinolide to differentiate sugarcane suspension cells into tracheary elements, which showed metaxylem-like reticulate or pitted SCW patterning. The differentiation led to increased lignin levels, mainly caused by S-lignin units, and a rise in p -coumarate, leading to increased p -coumarate:ferulate ratios. RNAseq analysis revealed massive transcriptional reprogramming during differentiation, with upregulation of genes associated with cell wall biogenesis and phenylpropanoid metabolism and downregulation of genes related to cell ision and primary metabolism. To better understand the differentiation process, we constructed regulatory networks of transcription factors and SCW-related genes based on co-expression analyses. Accordingly, we found multiple regulatory modules that may underpin SCW deposition in sugarcane. Our results provide important insights and resources to identify biotechnological strategies for sugarcane biomass optimization.
Assembly of an Interactive Correlation Network for the Arabidopsis Genome Using a Novel Heuristic Clustering Algorithm
Publisher: Oxford University Press (OUP)
Date: 04-11-2009
Abstract: A vital quest in biology is comprehensible visualization and interpretation of correlation relationships on a genome scale. Such relationships may be represented in the form of networks, which usually require disassembly into smaller manageable units, or clusters, to facilitate interpretation. Several graph-clustering algorithms that may be used to visualize biological networks are available. However, only some of these support weighted edges, and none provides good control of cluster sizes, which is crucial for comprehensible visualization of large networks. We constructed an interactive coexpression network for the Arabidopsis (Arabidopsis thaliana) genome using a novel Heuristic Cluster Chiseling Algorithm (HCCA) that supports weighted edges and that may control average cluster sizes. Comparative clustering analyses demonstrated that the HCCA performed as well as, or better than, the commonly used Markov, MCODE, and k-means clustering algorithms. We mapped MapMan ontology terms onto coexpressed node vicinities of the network, which revealed transcriptional organization of previously unrelated cellular processes. We further explored the predictive power of this network through mutant analyses and identified six new genes that are essential to plant growth. We show that the HCCA-partitioned network constitutes an ideal “cartographic” platform for visualization of correlation networks. This approach rapidly provides network partitions with relative uniform cluster sizes on a genome-scale level and may thus be used for correlation network layouts also for other species.
System-wide organization of actin cytoskeleton determines organelle transport in hypocotyl plant cells
Publisher: Proceedings of the National Academy of Sciences
Date: 27-06-2017
Abstract: In the crowded interior of a cell, diffusion alone is insufficient to master varying transport requirements for cell sustenance and growth. The dynamic actin cytoskeleton is an essential cellular component that provides transport and cytoplasmic streaming in plant cells, but little is known about its system-level organization. Here, we resolve key challenges in understanding system-level actin-based transport. We present an automated image-based, network-driven framework that accurately incorporates both actin cytoskeleton and organelle trafficking. We demonstrate that actin cytoskeleton network properties support efficient transport in both growing and elongated hypocotyl cells. We show that organelle transport can be predicted from the system-wide cellular organization of the actin cytoskeleton. Our framework can be readily applied to investigate cytoskeleton-based transport in other organisms.
Domestication of rice has reduced the occurrence of transposable elements within gene coding regions
Publisher: Springer Science and Business Media LLC
Date: 09-01-2017
Regulatory roles of phosphoinositides in membrane trafficking and their potential impact on cell-wall synthesis and re-modelling
Publisher: Oxford University Press (OUP)
Date: 25-04-2014
DOI: 10.1093/AOB/MCU055
Laying down the bricks: logistic aspects of cell wall biosynthesis
Publisher: Elsevier BV
Date: 12-2008
DOI: 10.1016/J.PBI.2008.08.003
Abstract: Plant cell wall polysaccharides are synthesised at the plasma membrane and in the Golgi apparatus. Current research efforts mainly try to address how these molecules are synthesised or modified. However, it is clear that polysaccharide synthesis in the two compartments needs to be carried out in a coordinated fashion, and that carbohydrates and proteins that are delivered from the Golgi to the cell surface have to undergo a range of modifications. Consequently, there appears to be a need for a fine-tuned system that coalesces signals from the wall, synthesis of carbohydrate-based molecules and vesicle shuttling. Several recent papers have scratched the surface for an initial understanding of these linked processes. For ex le, the impairment of the proton pumping activity in the trans-Golgi network, which is part of the cell's trafficking system, results in growth defects, changes in Golgi stack morphology and cellulose deficiency. An increased understanding of how cell wall synthesis is coordinated with the secretory machinery may facilitate avenues for modulating cell wall contents and therefore overall plant biomass.
Phosphatidylinositol 4,5-Bisphosphate Influences PIN Polarization by Controlling Clathrin-Mediated Membrane Trafficking inArabidopsis
Publisher: Oxford University Press (OUP)
Date: 12-2013
Abstract: The functions of the minor phospholipid phosphatidylinositol-4,5-bisphosphate [PtdIns(4,5)P2] during vegetative plant growth remain obscure. Here, we targeted two related phosphatidylinositol 4-phosphate 5-kinases (PI4P 5-kinases) PIP5K1 and PIP5K2, which are expressed ubiquitously in Arabidopsis thaliana. A pip5k1 pip5k2 double mutant with reduced PtdIns(4,5)P2 levels showed dwarf stature and phenotypes suggesting defects in auxin distribution. The roots of the pip5k1 pip5k2 double mutant had normal auxin levels but reduced auxin transport and altered distribution. Fluorescence-tagged auxin efflux carriers PIN-FORMED (PIN1)–green fluorescent protein (GFP) and PIN2-GFP displayed abnormal, partially apolar distribution. Furthermore, fewer brefeldin A–induced endosomal bodies decorated by PIN1-GFP or PIN2-GFP formed in pip5k1 pip5k2 mutants. Inducible overexpressor lines for PIP5K1 or PIP5K2 also exhibited phenotypes indicating misregulation of auxin-dependent processes, and immunolocalization showed reduced membrane association of PIN1 and PIN2. PIN cycling and polarization require clathrin-mediated endocytosis and labeled clathrin light chain also displayed altered localization patterns in the pip5k1 pip5k2 double mutant, consistent with a role for PtdIns(4,5)P2 in the regulation of clathrin-mediated endocytosis. Further biochemical tests on subcellular fractions enriched for clathrin-coated vesicles (CCVs) indicated that pip5k1 and pip5k2 mutants have reduced CCV-associated PI4P 5-kinase activity. Together, the data indicate an important role for PtdIns(4,5)P2 in the control of clathrin dynamics and in auxin distribution in Arabidopsis.
Carbon Supply and the Regulation of Cell Wall Synthesis
Publisher: Elsevier BV
Date: 2018
DOI: 10.1016/J.MOLP.2017.10.004
Abstract: All plant cells are surrounded by a cell wall that determines the directionality of cell growth and protects the cell against its environment. Plant cell walls are comprised primarily of polysaccharides and represent the largest sink for photosynthetically fixed carbon, both for in idual plants and in the terrestrial biosphere as a whole. Cell wall synthesis is a highly sophisticated process, involving multiple enzymes and metabolic intermediates, intracellular trafficking of proteins and cell wall precursors, assembly of cell wall polymers into the extracellular matrix, remodeling of polymers and their interactions, and recycling of cell wall sugars. In this review we discuss how newly fixed carbon, in the form of UDP-glucose and other nucleotide sugars, contributes to the synthesis of cell wall polysaccharides, and how cell wall synthesis is influenced by the carbon status of the plant, with a focus on the model species Arabidopsis (Arabidopsis thaliana).
Not Just a Simple Sugar: Arabinose Metabolism and Function in Plants
Publisher: Oxford University Press (OUP)
Date: 15-06-2021
DOI: 10.1093/PCP/PCAB087
Abstract: Growth, development, structure as well as dynamic adaptations and remodeling processes in plants are largely controlled by properties of their cell walls. These intricate wall structures are mostly made up of different sugars connected through specific glycosidic linkages but also contain many glycosylated proteins. A key plant sugar that is present throughout the plantae, even before the ergence of the land plant lineage, but is not found in animals, is l-arabinose (l-Ara). Here, we summarize and discuss the processes and proteins involved in l-Ara de novo synthesis, l-Ara interconversion, and the assembly and recycling of l-Ara-containing cell wall polymers and proteins. We also discuss the biological function of l-Ara in a context-focused manner, mainly addressing cell wall–related functions that are conferred by the basic physical properties of arabinose-containing polymers/compounds. In this article we explore these processes with the goal of directing future research efforts to the many exciting yet unanswered questions in this research area.
The genome and metabolome of the tobacco tree, Nicotiana glauca: a potential renewable feedstock for the bioeconomy
Publisher: Cold Spring Harbor Laboratory
Date: 20-06-2018
DOI: 10.1101/351429
Abstract: Given its tolerance to stress and its richness in particular secondary metabolites, the tobacco tree, Nicotiana glauca , has been considered a promising biorefinery feedstock that would not be competitive with food and fodder crops. Here we present a 3.5 Gbp draft sequence and annotation of the genome of N. glauca spanning 731,465 scaffold sequences, with an N50 size of approximately 92 kbases. Furthermore, we supply a comprehensive transcriptome and metabolome analysis of leaf development comprising multiple techniques and platforms. The genome sequence is predicted to cover nearly 80% of the estimated total genome size of N. glauca . With 73,799 genes predicted and a BUSCO score of 94.9%, we have assembled the majority of gene-rich regions successfully. RNA-Seq data revealed stage-and/or tissue-specific expression of genes, and we determined a general trend of a decrease of tricarboxylic acid cycle metabolites and an increase of terpenoids as well as some of their corresponding transcripts during leaf development. The N. glauca draft genome and its detailed transcriptome, together with paired metabolite data, constitute a resource for future studies of valuable compound analysis in tobacco species and present the first steps towards a further resolution of phylogenetic, whole genome studies in tobacco.
Secondary cell wall patterning—connecting the dots, pits and helices
Publisher: The Royal Society
Date: 05-2022
DOI: 10.1098/RSOB.210208
Abstract: All plant cells are encased in primary cell walls that determine plant morphology, but also protect the cells against the environment. Certain cells also produce a secondary wall that supports mechanically demanding processes, such as maintaining plant body stature and water transport inside plants. Both these walls are primarily composed of polysaccharides that are arranged in certain patterns to support cell functions. A key requisite for patterned cell walls is the arrangement of cortical microtubules that may direct the delivery of wall polymers and/or cell wall producing enzymes to certain plasma membrane locations. Microtubules also steer the synthesis of cellulose—the load-bearing structure in cell walls—at the plasma membrane. The organization and behaviour of the microtubule array are thus of fundamental importance to cell wall patterns. These aspects are controlled by the coordinated effort of small GTPases that probably coordinate a Turing's reaction–diffusion mechanism to drive microtubule patterns. Here, we give an overview on how wall patterns form in the water-transporting xylem vessels of plants. We discuss systems that have been used to dissect mechanisms that underpin the xylem wall patterns, emphasizing the VND6 and VND7 inducible systems, and outline challenges that lay ahead in this field.
Atkinesin-13A Modulates Cell-Wall Synthesis and Cell Expansion in Arabidopsis thaliana via the THESEUS1 Pathway
Publisher: Public Library of Science (PLoS)
Date: 18-09-2014
Cellulose Synthesis – Central Components and Their Evolutionary Relationships
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.TPLANTS.2019.02.011
Abstract: Cellulose is an essential morphogenic polysaccharide that is central to the stability of plant cell walls and provides an important raw material for a range of plant-based fiber and fuel industries. The past decade has seen a substantial rise in the identification of cellulose synthesis-related components and in our understanding of how these components function. Much of this research has been conducted in Arabidopsis thaliana (arabidopsis) however, it has become increasingly evident that many of the components and their functions are conserved. We provide here an overview of cellulose synthesis 'core' components. The evolution and coexpression patterns of these components provide important insight into how cellulose synthesis evolved and the potential for the components to work as functional units during cellulose production.
Multi-omics analyses of 398 foxtail millet accessions reveal genomic regions associated with domestication, metabolite traits, and anti-inflammatory effects
Publisher: Elsevier BV
Date: 08-2022
DOI: 10.1016/J.MOLP.2022.07.003
Abstract: Foxtail millet (Setaria italica), which was domesticated from the wild species green foxtail (Setaria viridis), is a rich source of phytonutrients for humans. To evaluate how breeding changed the metabolome of foxtail millet grains, we generated and analyzed the datasets encompassing the genomes, transcriptomes, metabolomes, and anti-inflammatory indices from 398 foxtail millet accessions. We identified hundreds of common variants that influence numerous secondary metabolites. We observed tremendous differences in natural variations of the metabolites and their underlying genetic architectures between distinct sub-groups of foxtail millet. Furthermore, we found that the selection of the gene alleles associated with yellow grains led to altered profiles of metabolites such as carotenoids and endogenous phytohormones. Using CRISPR-mediated genome editing we validated the function of PHYTOENE SYNTHASE 1 (PSY1) gene in affecting millet grain color and quality. Interestingly, our in vitro cell inflammation assays showed that 83 metabolites in millet grains have anti-inflammatory effects. Taken together, our multi-omics study illustrates how the breeding history of foxtail millet has shaped its metabolite profile. The datasets we generated in this study also provide important resources for further understanding how millet grain quality is affected by different metabolites, laying the foundations for future millet genetic research and metabolome-assisted improvement.
Cracking the elusive alignment hypothesis: the microtubule–cellulose synthase nexus unraveled
Publisher: Elsevier BV
Date: 11-2012
Current and future advances in fluorescence-based visualization of plant cell wall components and cell wall biosynthetic machineries
Publisher: Springer Science and Business Media LLC
Date: 29-03-2021
DOI: 10.1186/S13068-021-01922-0
Abstract: Plant cell wall-derived biomass serves as a renewable source of energy and materials with increasing importance. The cell walls are biomacromolecular assemblies defined by a fine arrangement of different classes of polysaccharides, proteoglycans, and aromatic polymers and are one of the most complex structures in Nature. One of the most challenging tasks of cell biology and biomass biotechnology research is to image the structure and organization of this complex matrix, as well as to visualize the compartmentalized, multiplayer biosynthetic machineries that build the elaborate cell wall architecture. Better knowledge of the plant cells, cell walls, and whole tissue is essential for bioengineering efforts and for designing efficient strategies of industrial deconstruction of the cell wall-derived biomass and its saccharification. Cell wall-directed molecular probes and analysis by light microscopy, which is capable of imaging with a high level of specificity, little s le processing, and often in real time, are important tools to understand cell wall assemblies. This review provides a comprehensive overview about the possibilities for fluorescence label-based imaging techniques and a variety of probing methods, discussing both well-established and emerging tools. Ex les of applications of these tools are provided. We also list and discuss the advantages and limitations of the methods. Specifically, we elaborate on what are the most important considerations when applying a particular technique for plants, the potential for future development, and how the plant cell wall field might be inspired by advances in the biomedical and general cell biology fields.
Phosphate starvation regulates cellulose synthesis to modify root growth
Publisher: Cold Spring Harbor Laboratory
Date: 17-09-2023
Cellulose squeezes through
Publisher: Springer Science and Business Media LLC
Date: 15-11-2010
DOI: 10.1038/NCHEMBIO.480
Cell Wall Heterogeneity in Root Development of Arabidopsis
Publisher: Frontiers Media SA
Date: 17-08-2016
Protocol for analyzing root halotropism using split-agar system in Arabidopsis thaliana
Publisher: Elsevier BV
Date: 06-2023
Structure of Arabidopsis CESA3 catalytic domain with its substrate UDP-glucose provides insight into the mechanism of cellulose synthesis
Publisher: Proceedings of the National Academy of Sciences
Date: 08-03-2021
Abstract: Cellulose is the most abundant biopolymer on Earth and has many potential industrial applications, such as renewable energy and sustainable materials. Here we report the apo and UDP-glucose (UDP-Glc)–bound crystal structures of the catalytic domain of Arabidopsis thaliana CESA3. Our results offer a structural basis for how the substrate UDP-Glc and a metal ion, Mn 2+ , which is required for cellulose synthesis, are coordinated in plant CESAs. Furthermore, our structure reveals that CESAs may form homodimers through interactions between specific beta strands that likely aid in the early stages of CESA complex formation.
Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)
Publisher: Informa UK Limited
Date: 02-01-2016
Live Cell Imaging Reveals Structural Associations between the Actin and Microtubule Cytoskeleton in Arabidopsis
Publisher: Oxford University Press (OUP)
Date: 06-2011
Abstract: In eukaryotic cells, the actin and microtubule (MT) cytoskeletal networks are dynamic structures that organize intracellular processes and facilitate their rapid reorganization. In plant cells, actin filaments (AFs) and MTs are essential for cell growth and morphogenesis. However, dynamic interactions between these two essential components in live cells have not been explored. Here, we use spinning-disc confocal microscopy to dissect interaction and cooperation between cortical AFs and MTs in Arabidopsis thaliana, utilizing fluorescent reporter constructs for both components. Quantitative analyses revealed altered AF dynamics associated with the positions and orientations of cortical MTs. Reorganization and reassembly of the AF array was dependent on the MTs following drug-induced depolymerization, whereby short AFs initially appeared colocalized with MTs, and displayed motility along MTs. We also observed that light-induced reorganization of MTs occurred in concert with changes in AF behavior. Our results indicate dynamic interaction between the cortical actin and MT cytoskeletons in interphase plant cells.
CytoSeg 2.0: automated extraction of actin filaments
Publisher: Oxford University Press (OUP)
Date: 23-01-2020
DOI: 10.1093/BIOINFORMATICS/BTAA035
Abstract: Actin filaments (AFs) are dynamic structures that substantially change their organization over time. The dynamic behavior and the relatively low signal-to-noise ratio during live-cell imaging have rendered the quantification of the actin organization a difficult task. We developed an automated image-based framework that extracts AFs from fluorescence microscopy images and represents them as networks, which are automatically analyzed to identify and compare biologically relevant features. Although the source code is freely available, we have now implemented the framework into a graphical user interface that can be installed as a Fiji plugin, thus enabling easy access by the research community. CytoSeg 2.0 is open-source software under the GPL and is available on Github: nowak90/CytoSeg2.0. Supplementary data are available at Bioinformatics online.
Sweet sorghum and Miscanthus : Two potential dedicated bioenergy crops in China
Publisher: Elsevier BV
Date: 06-2017
Novel Disease Susceptibility Factors for Fungal Necrotrophic Pathogens in Arabidopsis
Publisher: Public Library of Science (PLoS)
Date: 04-2015
Cellulose Synthases and Synthesis in Arabidopsis
Publisher: Elsevier BV
Date: 03-2011
DOI: 10.1093/MP/SSQ079
Abstract: Plant cell walls are complex structures composed of high-molecular-weight polysaccharides, proteins, and lignins. Among the wall polysaccharides, cellulose, a hydrogen-bonded β-1,4-linked glucan microfibril, is the main load-bearing wall component and a key precursor for industrial applications. Cellulose is synthesized by large multi-meric cellulose synthase (CesA) complexes, tracking along cortical microtubules at the plasma membrane. The only known components of these complexes are the cellulose synthase proteins. Recent studies have identified tentative interaction partners for the CesAs and shown that the migratory patterns of the CesA complexes depend on phosphorylation status. These advances may become good platforms for expanding our knowledge about cellulose synthesis in the near future. In addition, our current understanding of cellulose chain polymerization in the context of the CesA complex is discussed.
CESA TRAFFICKING INHIBITOR Inhibits Cellulose Deposition and Interferes with the Trafficking of Cellulose Synthase Complexes and Their Associated Proteins KORRIGAN1 and POM2/CELLULOSE SYNTHASE INTERAC
Publisher: Oxford University Press (OUP)
Date: 22-12-2014
Connecting two arrays: The emerging role of actin-microtubule cross-linking motor proteins
Publisher: Frontiers Media SA
Date: 02-06-2015
Toward a Systems Approach to Understanding Plant Cell Walls
Publisher: American Association for the Advancement of Science (AAAS)
Date: 24-12-2004
Abstract: One of the defining features of plants is a body plan based on the physical properties of cell walls. Structural analyses of the polysaccharide components, combined with high-resolution imaging, have provided the basis for much of the current understanding of cell walls. The application of genetic methods has begun to provide new insights into how walls are made, how they are controlled, and how they function. However, progress in integrating biophysical, developmental, and genetic information into a useful model will require a system-based approach.
GeneCAT—novel webtools that combine BLAST and co-expression analyses
Publisher: Oxford University Press (OUP)
Date: 14-05-2008
DOI: 10.1093/NAR/GKN292
CHITINASE-LIKE1/POM-POM1 and Its Homolog CTL2 Are Glucan-Interacting Proteins Important for Cellulose Biosynthesis in Arabidopsis
Publisher: Oxford University Press (OUP)
Date: 02-2012
A network-based framework for shape analysis enables accurate characterization of leaf epidermal cells
Publisher: Springer Science and Business Media LLC
Date: 19-01-2021
DOI: 10.1038/S41467-020-20730-Y
Abstract: Cell shape is crucial for the function and development of organisms. Yet, versatile frameworks for cell shape quantification, comparison, and classification remain underdeveloped. Here, we introduce a visibility graph representation of shapes that facilitates network-driven characterization and analyses across shapes encountered in different domains. Using the ex le of complex shape of leaf pavement cells, we show that our framework accurately quantifies cell protrusions and invaginations and provides additional functionality in comparison to the contending approaches. We further show that structural properties of the visibility graphs can be used to quantify pavement cell shape complexity and allow for classification of plants into their respective phylogenetic clades. Therefore, the visibility graphs provide a robust and unique framework to accurately quantify and classify the shape of different objects.
A receptor-like kinase controls the amplitude of secondary cell wall synthesis in rice
Publisher: Elsevier BV
Date: 02-2023
The relationship between starch structure and digestibility by time-course digestion of amylopectin-only and amylose-only barley starches
Publisher: Elsevier BV
Date: 05-2023
Differential Regulation of Clathrin and Its Adaptor Proteins during Membrane Recruitment for Endocytosis
Publisher: Oxford University Press (OUP)
Date: 04-03-2016
DOI: 10.1104/PP.15.01716
Phylogenetic Analyses and Expression Studies Reveal Two Distinct Groups of Calreticulin Isoforms in Higher Plants
Publisher: Oxford University Press (OUP)
Date: 11-2003
Abstract: Calreticulin (CRT) is a multifunctional protein mainly localized to the endoplasmic reticulum in eukaryotic cells. Here, we present the first analysis, to our knowledge, of evolutionary ersity and expression profiling among different plant CRT isoforms. Phylogenetic studies and expression analysis show that higher plants contain two distinct groups of CRTs: a CRT1/CRT2 group and a CRT3 group. To corroborate the existence of these isoform groups, we cloned a putative CRT3 ortholog from Brassica rapa. The CRT3 gene appears to be most closely related to the ancestral CRT gene in higher plants. Distinct tissue-dependent expression patterns and stress-related regulation were observed for the isoform groups. Furthermore, analysis of posttranslational modifications revealed differences in the glycosylation status among members within the CRT1/CRT2 isoform group. Based on evolutionary relationship, a new nomenclature for plant CRTs is suggested. The presence of two distinct CRT isoform groups, with distinct expression patterns and posttranslational modifications, supports functional specificity among plant CRTs and could account for the multiple functional roles assigned to CRTs.
Genetic Evidence That Cellulose Synthase Activity Influences Microtubule Cortical Array Organization
Publisher: Oxford University Press (OUP)
Date: 26-06-2008
Abstract: To identify factors that influence cytoskeletal organization we screened for Arabidopsis (Arabidopsis thaliana) mutants that show hypersensitivity to the microtubule destabilizing drug oryzalin. We cloned the genes corresponding to two of the 131 mutant lines obtained. The genes encoded mutant alleles of PROCUSTE1 and KORRIGAN, which both encode proteins that have previously been implicated in cellulose synthesis. Analysis of microtubules in the mutants revealed that both mutants have altered orientation of root cortical microtubules. Similarly, isoxaben, an inhibitor of cellulose synthesis, also altered the orientation of cortical microtubules while exogenous cellulose degradation did not. Thus, our results substantiate that proteins involved in cell wall biosynthesis influence cytoskeletal organization and indicate that this influence on cortical microtubule stability and orientation is correlated with cellulose synthesis rather than the integrity of the cell wall.
The Ca2+ Status of the Endoplasmic Reticulum Is Altered by Induction of Calreticulin Expression in Transgenic Plants
Publisher: Oxford University Press (OUP)
Date: 07-2001
Abstract: To investigate the endoplasmic reticulum (ER) Ca2+ stores in plant cells, we generated tobacco (Nicotiana tabacum NT1) suspension cells and Arabidopsis plants with altered levels of calreticulin (CRT), an ER-localized Ca2+-binding protein. NT1 cells and Arabidopsis plants were transformed with a maize (Zea mays) CRT gene in both sense and antisense orientations under the control of an Arabidopsis heat shock promoter. ER-enriched membrane fractions from NT1 cells were used to examine how altered expression of CRT affects Ca2+uptake and release. We found that a 2.5-fold increase in CRT led to a 2-fold increase in ATP-dependent 45Ca2+accumulation in the ER-enriched fraction compared with heat-shocked wild-type controls. Furthermore, after treatment with the Ca2+ ionophore ionomycin, ER microsomes from NT1 cells overproducing CRT showed a 2-fold increase in the amount of45Ca2+ released, and a 2- to 3-fold increase in the amount of 45Ca2+ retained compared with wild type. These data indicate that altering the production of CRT affects the ER Ca2+ pool. In addition, CRTtransgenic Arabidopsis plants were used to determine if altered CRT levels had any physiological effects. We found that the level of CRT in heat shock-induced CRT transgenic plants correlated positively with the retention of chlorophyll when the plants were transferred from Ca2+-containing medium to Ca2+-depleted medium. Together these data are consistent with the hypothesis that increasing CRT in the ER increases the ER Ca2+ stores and thereby enhances the survival of plants grown in low Ca2+ medium.
Root twisting drives halotropism via stress-induced microtubule reorientation
Publisher: Elsevier BV
Date: 10-2022
DOI: 10.1016/J.DEVCEL.2022.09.012
Abstract: Plants have evolved signaling mechanisms that guide growth away from adverse environments that can cause yield losses. Root halotropism is a sodium-specific negative tropism that is crucial for surviving and thriving under high salinity. Although root halotropism was discovered some years ago, the underlying molecular and cellular mechanisms remain unknown. Here, we show that abscisic acid (ABA)-mediated root twisting determines halotropism in Arabidopsis. An ABA-activated SnRK2 protein kinase (SnRK2.6) phosphorylates the microtubule-associated protein SP2L at Ser406, which induces a change in the anisotropic cell expansion at the root transition zone and is required for root twisting during halotropism. Salt stress triggers SP2L-mediated cortical microtubule reorientation, which guides cellulose microfibril patterns. Our findings thus outline the molecular mechanism of root halotropism and indicate that anisotropic cell expansion through microtubule reorientation and microfibril deposition has a central role in mediating tropic responses.
Cellulose-Microtubule Uncoupling Proteins Prevent Lateral Displacement of Microtubules during Cellulose Synthesis in Arabidopsis
Publisher: Elsevier BV
Date: 08-2016
DOI: 10.1016/J.DEVCEL.2016.06.032
Abstract: Cellulose is the most abundant biopolymer on Earth and is the major contributor to plant morphogenesis. Cellulose is synthesized by plasma membrane-localized cellulose synthase complexes (CSCs). Nascent cellulose microfibrils become entangled in the cell wall, and further catalysis therefore drives the CSC forward through the membrane: a process guided by cortical microtubules via the protein CSI1/POM2. Still, it is unclear how the microtubules can withstand the forces generated by the motile CSCs to effectively direct CSC movement. Here, we identified a family of microtubule-associated proteins, the cellulose synthase-microtubule uncouplings (CMUs), that located as static puncta along cortical microtubules. Functional disruption of the CMUs caused lateral microtubule displacement and compromised microtubule-based guidance of CSC movement. CSCs that traversed the microtubules interacted with the microtubules via CSI1/POM2, which prompted the lateral microtubule displacement. Hence, we have revealed how microtubules can withstand the propulsion of the CSCs during cellulose biosynthesis and thus sustain anisotropic plant cell growth.
The connection of cytoskeletal network with plasma membrane and the cell wall
Publisher: Wiley
Date: 04-2015
DOI: 10.1111/JIPB.12342
Cell cycle-regulated PLEIADE/AtMAP65-3 links membrane and microtubule dynamics during plant cytokinesis
Publisher: Wiley
Date: 05-10-2016
DOI: 10.1111/TPJ.13275
Abstract: Cytokinesis, the partitioning of the cytoplasm following nuclear ision, requires extensive coordination between cell cycle cues, membrane trafficking and microtubule dynamics. Plant cytokinesis occurs within a transient membrane compartment known as the cell plate, to which vesicles are delivered by a plant-specific microtubule array, the phragmoplast. While membrane proteins required for cytokinesis are known, how these are coordinated with microtubule dynamics and regulated by cell cycle cues remains unclear. Here, we document physical and genetic interactions between Transport Protein Particle II (TRAPPII) tethering factors and microtubule-associated proteins of the PLEIADE/AtMAP65 family. These interactions do not specifically affect the recruitment of either TRAPPII or MAP65 proteins to the cell plate or midzone. Rather, and based on single versus double mutant phenotypes, it appears that they are required to coordinate cytokinesis with the nuclear ision cycle. As MAP65 family members are known to be targets of cell cycle-regulated kinases, our results provide a conceptual framework for how membrane and microtubule dynamics may be coordinated with each other and with the nuclear cycle during plant cytokinesis.
Cellulose and callose synthesis and organization in focus, what's new?
Publisher: Elsevier BV
Date: 12-2016
DOI: 10.1016/J.PBI.2016.07.007
Abstract: Plant growth and development are supported by plastic but strong cell walls. These walls consist largely of polysaccharides that vary in content and structure. Most of the polysaccharides are produced in the Golgi apparatus and are then secreted to the apoplast and built into the growing walls. However, the two glucan polymers cellulose and callose are synthesized at the plasma membrane by cellulose or callose synthase complexes, respectively. Cellulose is the most common cell wall polymer in land plants and provides strength to the walls to support directed cell expansion. In contrast, callose is integral to specialized cell walls, such as the cell plate that separates iding cells and growing pollen tube walls, and maintains important functions during abiotic and biotic stress responses. The last years have seen a dramatic increase in our understanding of how cellulose and callose are manufactured, and new factors that regulate the synthases have been identified. Much of this knowledge has been amassed via various microscopy-based techniques, including various confocal techniques and super-resolution imaging. Here, we summarize and synthesize recent findings in the fields of cellulose and callose synthesis in plant biology.
Primary wall cellulose synthase regulates shoot apical meristem mechanics and growth
Publisher: The Company of Biologists
Date: 2019
DOI: 10.1242/DEV.179036
Abstract: How organisms attain their specific shapes and modify their growth patterns in response to environmental and chemical signals has been the subject of many investigations. Plant cells are at high turgor pressure, and are surrounded by a rigid yet flexible cell wall, which is the primary determinant of plant growth and morphogenesis. Cellulose microfibrils, synthesized by plasma membrane-localized cellulose synthase complexes, are major tension-bearing components of the cell wall that mediate directional growth. Despite advances in understanding genetic and biophysical regulation of morphogenesis, direct studies on cellulose biosynthesis and its impact on morphogenesis of different cell and tissue types are largely lacking. In this study, we take advantage of mutants of three primary cellulose synthase (CESA) genes that are involved in primary wall cellulose synthesis. Using field emission scanning electron microscopy, live cell imaging and biophysical measurements, we aimed to understand how the primary wall CESA complex acts during shoot apical meristem development. Our results indicate that cellulose biosynthesis impacts the mechanics and growth of the shoot apical meristem.
Phosphate starvation regulates cellulose synthesis to modify root growth
Publisher: Oxford University Press (OUP)
Date: 12-10-2023
Functional Characterization of Arabidopsis Calreticulin1a: A Key Alleviator of Endoplasmic Reticulum Stress
Publisher: Oxford University Press (OUP)
Date: 15-04-2008
DOI: 10.1093/PCP/PCN065
Abstract: The chaperone calreticulin plays important roles in a variety of processes in the endoplasmic reticulum (ER) of animal cells, such as Ca2+ signaling and protein folding. Although the functions of calreticulin are well characterized in animals, only indirect evidence is available for plants. To increase our understanding of plant calreticulins we introduced one of the Arabidopsis isoforms, AtCRT1a, into calreticulin-deficient (crt-/-) mouse embryonic fibroblasts. As a result of calreticulin deficiency, the mouse crt-/- fibroblasts have decreased levels of Ca2+ in the ER and impaired protein folding abilities. Expression of the AtCRT1a in mouse crt-/- fibroblasts rescued these phenotypes, i.e. AtCRT1a restored the Ca2+-holding capacity and chaperone functions in the ER of the mouse crt-/- fibroblasts, demonstrating that the animal sorting machinery was also functional for a plant protein, and that basic calreticulin functions are conserved across the Kingdoms. Expression analyses using a beta-glucuronidase (GUS)-AtCRT1a promoter construct revealed high expression of CRT1a in root tips, floral tissues and in association with vascular bundles. To assess the impact of AtCRT1a in planta, we generated Atcrt1a mutant plants. The Atcrt1a mutants exhibited increased sensitivity to the drug tunicamycin, an inducer of the unfolded protein response. We therefore conclude that AtCRT1a is an alleviator of the tunicamycin-induced unfolded protein response, and propose that the use of the mouse crt-/- fibroblasts as a calreticulin expression system may prove useful to assess functionalities of calreticulins from different species.
The Cellulose Synthases Are Cargo of the TPLATE Adaptor Complex
Publisher: Elsevier BV
Date: 02-2018
Change your Tplate, change your fate: plant CME and beyond
Publisher: Elsevier BV
Date: 2015
DOI: 10.1016/J.TPLANTS.2014.09.002
Abstract: Clathrin-mediated endocytosis (CME) is the predominant and evolutionarily conserved pathway by which eukaryotes internalize cargoes (i.e., plasma membrane proteins, lipids, and extracellular material) that are engaged in a variety of processes. Initiation of CME relies on adaptor proteins, which precisely select the cargoes for internalization, recruit the clathrin cage, and start membrane curvature. The recently identified CME early adaptor complex, the TPLATE complex (TPC), is essential for CME in plants. Phylogenetic analyses suggest that the TPC evolved from an ancient protein complex involved in vesicle trafficking in early eukaryotes, which raises questions about CME evolution and adaptation within the eukaryotic Kingdoms. In this review, we focus on the early events of plant CME and explore evolutionary aspects related to CME in other eukaryotes.
The 2′-O-methyladenosine nucleoside modification gene OsTRM13 positively regulates salt stress tolerance in rice
Publisher: Oxford University Press (OUP)
Date: 03-2017
DOI: 10.1093/JXB/ERX061
FamNet: A Framework to Identify Multiplied Modules Driving Pathway Expansion in Plants
Publisher: Oxford University Press (OUP)
Date: 11-01-2016
DOI: 10.1104/PP.15.01281
Co-ordination and divergence of cell-specific transcription and translation of genes in arabidopsis root cells
Publisher: Oxford University Press (OUP)
Date: 22-08-2014
DOI: 10.1093/AOB/MCU151
An integrated genomic and metabolomic framework for cell wall biology in rice
Publisher: Springer Science and Business Media LLC
Date: 15-07-2014
Bright Fluorescent Vacuolar Marker Lines Allow Vacuolar Tracing Across Multiple Tissues and Stress Conditions in Rice
Publisher: MDPI AG
Date: 12-06-2020
DOI: 10.3390/IJMS21124203
Abstract: The vacuole is indispensable for cells to maintain their water potential and to respond to environmental changes. Nevertheless, investigations of vacuole morphology and its functions have been limited to Arabidopsis thaliana with few studies in the model crop rice (Oryza sativa). Here, we report the establishment of bright rice vacuole fluorescent reporter systems using OsTIP1 , a tonoplast water channel protein, fused to either an enhanced green fluorescent protein or an mCherry red fluorescent protein. We used the corresponding transgenic rice lines to trace the vacuole morphology in roots, leaves, anthers, and pollen grains. Notably, we observed dynamic changes in vacuole morphologies in pollen and root epidermis that corresponded to their developmental states as well as vacuole shape alterations in response to abiotic stresses. Our results indicate that the application of our vacuole markers may aid in understanding rice vacuole function and structure across different tissues and environmental conditions in rice.
Expression of bovine calmodulin in tobacco plants confers faster germination on saline media
Publisher: Elsevier BV
Date: 06-2004
Noninvasive Long-Term Imaging of the Cytoskeleton in Arabidopsis Seedlings
Publisher: Springer US
Date: 2023
Plant Cytokinesis Is Orchestrated by the Sequential Action of the TRAPPII and Exocyst Tethering Complexes
Publisher: Elsevier BV
Date: 06-2014
DOI: 10.1016/J.DEVCEL.2014.04.029
Abstract: Plant cytokinesis is initiated in a transient membrane compartment, the cell plate, and completed by a process of maturation during which the cell plate becomes a cross wall. How the transition from juvenile to adult stages occurs is poorly understood. In this study, we monitor the Arabidopsis transport protein particle II (TRAPPII) and exocyst tethering complexes throughout cytokinesis. We show that their appearance is predominantly sequential, with brief overlap at the onset and end of cytokinesis. The TRAPPII complex is required for cell plate biogenesis, and the exocyst is required for cell plate maturation. The TRAPPII complex sorts plasma membrane proteins, including exocyst subunits, at the cell plate throughout cytokinesis. We show that the two tethering complexes physically interact and propose that their coordinated action may orchestrate not only plant but also animal cytokinesis.
Two Complementary Mechanisms Underpin Cell Wall Patterning during Xylem Vessel Development
Publisher: Oxford University Press (OUP)
Date: 25-09-2017
DOI: 10.1105/TPC.17.00309
Inositol signaling and plant growth
Publisher: Elsevier BV
Date: 06-2000
DOI: 10.1016/S1360-1385(00)01652-6
Abstract: Living organisms have evolved to contain a wide variety of receptors and signaling pathways that are essential for their survival in a changing environment. Of these, the phosphoinositide pathway is one of the best conserved. The ability of the phosphoinositides to permeate both hydrophobic and hydrophilic environments, and their erse functions within cells have contributed to their persistence in nature. In eukaryotes, phosphoinositides are essential metabolites as well as labile messengers that regulate cellular physiology while traveling within and between cells. The stereospecificity of the six hydroxyls on the inositol ring provides the basis for the functional ersity of the phosphorylated isomers that, in turn, generate a selective means of intracellular and intercellular communication for coordinating cell growth. Although such complexity presents a difficult challenge for bench scientists, it is ideal for the regulation of cellular functions in living organisms.
TRICHOME BIREFRINGENCEand Its HomologAT5G01360Encode Plant-Specific DUF231 Proteins Required for Cellulose Biosynthesis in Arabidopsis
Publisher: Oxford University Press (OUP)
Date: 13-04-2010
Abstract: The Arabidopsis (Arabidopsis thaliana) trichome birefringence (tbr) mutant has severely reduced crystalline cellulose in trichomes, but the molecular nature of TBR was unknown. We determined TBR to belong to the plant-specific DUF231 domain gene family comprising 46 members of unknown function in Arabidopsis. The genes harbor another plant-specific domain, called the TBL domain, which contains a conserved GDSL motif known from some esterases/lipases. TBR and TBR-like3 (TBL3) are transcriptionally coordinated with primary and secondary CELLULOSE SYNTHASE (CESA) genes, respectively. The tbr and tbl3 mutants hold lower levels of crystalline cellulose and have altered pectin composition in trichomes and stems, respectively, tissues generally thought to contain mainly secondary wall crystalline cellulose. In contrast, primary wall cellulose levels remain unchanged in both mutants as measured in etiolated tbr and tbl3 hypocotyls, while the amount of esterified pectins is reduced and pectin methylesterase activity is increased in this tissue. Furthermore, etiolated tbr hypocotyls have reduced length with swollen epidermal cells, a phenotype characteristic for primary cesa mutants or the wild type treated with cellulose synthesis inhibitors. Taken together, we show that two TBL genes contribute to the synthesis and deposition of secondary wall cellulose, presumably by influencing the esterification state of pectic polymers.
Golgi-localized STELLO proteins regulate the assembly and trafficking of cellulose synthase complexes in Arabidopsis
Publisher: Springer Science and Business Media LLC
Date: 09-06-2016
DOI: 10.1038/NCOMMS11656
Abstract: As the most abundant biopolymer on Earth, cellulose is a key structural component of the plant cell wall. Cellulose is produced at the plasma membrane by cellulose synthase (CesA) complexes (CSCs), which are assembled in the endomembrane system and trafficked to the plasma membrane. While several proteins that affect CesA activity have been identified, components that regulate CSC assembly and trafficking remain unknown. Here we show that STELLO1 and 2 are Golgi-localized proteins that can interact with CesAs and control cellulose quantity. In the absence of STELLO function, the spatial distribution within the Golgi, secretion and activity of the CSCs are impaired indicating a central role of the STELLO proteins in CSC assembly. Point mutations in the predicted catalytic domains of the STELLO proteins indicate that they are glycosyltransferases facing the Golgi lumen. Hence, we have uncovered proteins that regulate CSC assembly in the plant Golgi apparatus.
The cellulose synthase companion proteins act non-redundantly with CELLULOSE SYNTHASE INTERACTING1/POM2 and CELLULOSE SYNTHASE 6
Publisher: Informa UK Limited
Date: 02-2016
CELLULOSE SYNTHASE INTERACTING 1 is required for wood mechanics and leaf morphology in aspen
Publisher: Wiley
Date: 10-07-2020
DOI: 10.1111/TPJ.14873
Synthetic biosensor for mapping dynamic responses and spatio‐temporal distribution of jasmonate in rice
Publisher: Wiley
Date: 05-11-2021
DOI: 10.1111/PBI.13718
Cellulose synthesis across kingdoms
Publisher: Elsevier BV
Date: 05-2023
AtTrm5a catalyses 1-methylguanosine and 1-methylinosine formation on tRNAs and is important for vegetative and reproductive growth in Arabidopsis thaliana
Publisher: Oxford University Press (OUP)
Date: 12-2018
DOI: 10.1093/NAR/GKY1205
Transition of primary to secondary cell wall synthesis
Publisher: Elsevier BV
Date: 06-2016
AtCSLD3 and GhCSLD3 mediate root growth and cell elongation downstream of the ethylene response pathway in Arabidopsis
Publisher: Oxford University Press (OUP)
Date: 14-12-2017
DOI: 10.1093/JXB/ERX470
Impaired Cellulose Synthase Guidance Leads to Stem Torsion and Twists Phyllotactic Patterns in Arabidopsis
Publisher: Elsevier BV
Date: 05-2013
DOI: 10.1016/J.CUB.2013.04.013
Abstract: The parallel alignment of stiff cellulose microfibrils in plant-cell walls mediates anisotropic growth. This is largely controlled by cortical microtubules, which drive the insertion and trajectory of the cellulose synthase (CESA) complex at the plasma membrane. The CESA interactive protein 1 (CSI1) acts as a physical linker between CESA and cortical microtubules. Here we show that the inflorescence stems of csi1 mutants exhibit subtle right-handed torsion. Because cellulose deposition is largely uncoupled from cortical microtubules in csi1, we hypothesize that strictly transverse deposition of microfibrils in the wild-type is replaced by a helical orientation of uniform handedness in the mutant and that the helical microfibril alignment generates torsion. Interestingly, both elastic and viscous models for an expanding cell predict that a net helical orientation of microfibrils gives rise to a torque. We indeed observed tilted microfibrils in csi1 cells, and the torsion was almost absent in a csi1 prc1 background with impaired cellulose synthesis. In addition, the stem torsion led to a novel bimodal and robust phyllotactic pattern in the csi1 mutant, illustrating how growth perturbations can replace one robust mathematical pattern with a different, equally robust pattern.
The Cell Biology of Cellulose Synthesis
Publisher: Annual Reviews
Date: 29-04-2014
DOI: 10.1146/ANNUREV-ARPLANT-050213-040240
Abstract: Plant stature and development are governed by cell proliferation and directed cell growth. These parameters are determined largely by cell wall characteristics. Cellulose microfibrils, composed of hydrogen-bonded β-1,4 glucans, are key components for anisotropic growth in plants. Cellulose is synthesized by plasma membrane–localized cellulose synthase complexes. In higher plants, these complexes are assembled into hexameric rosettes in intracellular compartments and secreted to the plasma membrane. Here, the complexes typically track along cortical microtubules, which may guide cellulose synthesis, until the complexes are inactivated and/or internalized. Determining the regulatory aspects that control the behavior of cellulose synthase complexes is vital to understanding directed cell and plant growth and to tailoring cell wall content for industrial products, including paper, textiles, and fuel. In this review, we summarize and discuss cellulose synthesis and regulatory aspects of the cellulose synthase complex, focusing on Arabidopsis thaliana.
Genetic evidence for three unique components in primary cell-wall cellulose synthase complexes in Arabidopsis
Publisher: Proceedings of the National Academy of Sciences
Date: 25-09-2007
Abstract: In higher plants, cellulose is synthesized at the plasma membrane by the cellulose synthase (CESA) complex. The catalytic core of the complex is believed to be composed of three types of CESA subunits. Indirect evidence suggests that the complex associated with primary wall cellulose deposition consists of CESA1, -3, and -6 in Arabidopsis thaliana . However, phenotypes associated with mutations in two of these genes, CESA1 and -6 , suggest unequal contribution by the different CESAs to overall enzymatic activity of the complex. We present evidence that the primary complex requires three unique types of components, CESA1-, CESA3-, and CESA6-related, for activity. Removal of any of these components results in gametophytic lethality due to pollen defects, demonstrating that primary-wall cellulose synthesis is necessary for pollen development. We also show that the CESA6-related CESAs are partially functionally redundant.
AUXIN RESPONSE FACTORS 6 and 17 control the flag leaf angle in rice by regulating secondary cell wall biosynthesis of lamina joints
Publisher: Oxford University Press (OUP)
Date: 10-07-2021
Abstract: Flag leaf angle impacts the photosynthetic capacity of densely grown plants and is thus an important agronomic breeding trait for crop architecture and yield. The hormone auxin plays a key role in regulating this trait, yet the underlying molecular and cellular mechanisms remain unclear. Here, we report that two rice (Oryza sativa) auxin response factors (ARFs), OsARF6 and OsARF17, which are highly expressed in lamina joint tissues, control flag leaf angle in response to auxin. Loss-of-function double osarf6 osarf17 mutants displayed reduced secondary cell wall levels of lamina joint sclerenchymatous cells (Scs), resulting in an exaggerated flag leaf angle and decreased grain yield under dense planting conditions. Mechanical measurements indicated that the mutant lamina joint tissues were too weak to support the weight of the flag leaf blade, resembling the phenotype of the rice increased leaf angle1 (ila1) mutant. We demonstrate that OsARF6 and OsARF17 directly bind to the ILA1 promoter independently and synergistically to activate its expression. In addition, auxin-induced ILA1 expression was dependent on OsARF6 and OsARF17. Collectively, our study reveals a mechanism that integrates auxin signaling with the secondary cell wall composition to determine flag leaf angle, providing breeding targets in rice, and potentially other cereals, for this key trait.
Modeling the molecular structures and dynamics responsible for the remarkable mechanical properties of a plant cell wall
Publisher: Faculty Opinions Ltd
Date: 2022
Abstract: The primary plant cell wall is a hydrated meshwork of polysaccharides that is strong enough to withstand large mechanical stresses imposed by turgor while remaining pliant in ways that permit growth. To understand how its macromolecular architecture produces its complex mechanical properties, Zhang et al.1 computationally assembled a realistic network of cellulose microfibrils, hemicellulose, and pectin. The simulated wall responded to computationally applied stress like the real wall on which it was based. The model showed the location and chemical identity of stress-bearing components. It showed that cellulose microfibril interactions and movements dominated the wall’s mechanical behavior, while hemicellulose and pectin had surprisingly minor effects.
Correction for Breuer et al., System-wide organization of actin cytoskeleton determines organelle transport in hypocotyl plant cells
Publisher: Proceedings of the National Academy of Sciences
Date: 31-07-2017
Long-term single-cell imaging and simulations of microtubules reveal driving forces for wall pattering during proto-xylem development
Publisher: Cold Spring Harbor Laboratory
Date: 14-02-2020
DOI: 10.1101/2020.02.13.938258
Abstract: Plants are the tallest organisms on Earth a feature sustained by solute-transporting xylem vessels in the plant vasculature. The xylem vessels are supported by strong cell walls that are assembled in intricate patterns. Cortical microtubules direct wall deposition and need to rapidly re-organize during xylem cell development. We established long-term live-cell imaging of single Arabidopsis cells undergoing proto-xylem trans-differentiation, resulting in spiral wall patterns, to investigate the microtubule re-organization. The initial disperse microtubule array rapidly readjusted into well-defined microtubule bands, which required local de-stabilization of in idual microtubules in band-interspersing gap regions. Using extensive microtubule simulations, we could recapitulate the process in silico and found that local recruitment of microtubule-bound nucleation is critical for pattern formation, which we confirmed in vivo . Our simulations further indicated that the initial microtubule alignment impact microtubule band patterning. We confirmed this prediction using katanin mutants, which have microtubule organization defects, and uncovered active KATANIN recruitment to the forming microtubule bands. Our combination of quantitative microscopy and modelling outlines a framework towards a comprehensive understanding of microtubule re-organization during wall pattern formation.
Cellulose synthase complexes display distinct dynamic behaviors during xylem transdifferentiation
Publisher: Proceedings of the National Academy of Sciences
Date: 05-06-2018
Abstract: Cellulose, the most abundant biopolymer on earth, is the major constituent of plant cell walls and is ubiquitously used by industry. This biopolymer is made by plasma membrane-localized CELLULOSE SYNTHASE (CESA) enzymes. To transit from deposition of a growing primary cell wall to a strong secondary cell wall, xylem cells must remodel the CESA machinery to express a new set of CESA isoforms specific to secondary cell wall synthesis. We outline a detailed framework for how this change in cellulose synthesis occurs. Our work provides the principles for how plants change their capacity to produce cellulose and therefore plant biomass.
Identification of a novel calreticulin isoform (Crt2) in human and mouse
Publisher: Elsevier BV
Date: 09-2002
DOI: 10.1016/S0378-1119(02)00880-6
Abstract: Calreticulin is a Ca(2+)-binding chaperone localized mainly in the endoplasmic/sarcoplasmic reticulum in all higher organisms. To date, only one calreticulin isoform has been identified in human and mouse. Here we report a novel calreticulin isoform (Crt2) in human and mouse, with 53 (human) and 49% (mouse) identity to the previously identified calreticulin in respective species. The gene encoding the novel human calreticulin isoform spans 17 kb of genomic DNA and is expressed in testis, showing a similar expression as the chaperone calmegin. Phylogenetic analysis shows that two or more calreticulin (crt) genes are present both in plants and in mammals. The duplication of the crt gene in human and mouse suggests functional ersity, and variations in expression patterns among calreticulins. Two novel calreticulin (Crt2) isoforms, with high homology to the human and mouse calreticulin isoform (Crt2), were also identified in pig and rat via expressed sequence tags.
Brassinosteroids Influence Arabidopsis Hypocotyl Graviresponses Through Changes In Mannans And Cellulose
Publisher: Cold Spring Harbor Laboratory
Date: 22-02-2019
DOI: 10.1101/557777
Abstract: The force of gravity is a constant environmental factor. Plant shoots respond to gravity through negative gravitropism and gravity resistance. These responses are essential for plants to direct the growth of aerial organs away from the soil surface after germination and to keep an upright posture above ground. We took advantage of the effect of brassinosteroids on the two types of graviresponses in Arabidopsis thaliana hypocotyls to disentangle functions of cell wall polymers during etiolated shoot growth. The ability of etiolated Arabidopsis seedlings to grow upwards was suppressed in the presence of 24-epibrassinolide (EBL) but enhanced in the presence of brassinazole (BRZ), an inhibitor of brassinosteroid biosynthesis. These effects were accompanied by changes in cell wall mechanics and composition. Cell wall biochemical analyses and confocal microscopy of the cellulose-specific pontamine S4B dye revealed that the EBL and BRZ treatments correlated with changes in cellulose fibre organization and mannan content. Indeed, a longitudinal re-orientation of cellulose fibres supported upright growth whereas the presence of mannans reduced gravitropic bending. The negative effect of mannans on gravitropism is a new function for this class of hemicelluloses, highlighting evolutionary adaptations by which aquatic ancestors of terrestrial plants colonized land.
Subfunctionalization of Cellulose Synthases in Seed Coat Epidermal Cells Mediates Secondary Radial Wall Synthesis and Mucilage Attachment
Publisher: Oxford University Press (OUP)
Date: 12-07-2011
Abstract: Arabidopsis (Arabidopsis thaliana) epidermal seed coat cells follow a complex developmental program where, following fertilization, cells of the ovule outer integument differentiate into a unique cell type. Two hallmarks of these cells are the production of a doughnut-shaped apoplastic pocket filled with pectinaceous mucilage and the columella, a thick secondary cell wall. Cellulose is thought to be a key component of both these secondary cell wall processes. Here, we investigated the role of cellulose synthase (CESA) subunits CESA2, CESA5, and CESA9 in the seed coat epidermis. We characterized the roles of these CESA proteins in the seed coat by analyzing cell wall composition and morphology in cesa mutant lines. Mutations in any one of these three genes resulted in lower cellulose content, a loss of cell shape uniformity, and reduced radial wall integrity. In addition, we found that attachment of the mucilage halo to the parent seed following extrusion is maintained by cellulose-based connections requiring CESA5. Hence, we show that cellulose fulfills an adhesion role between the extracellular mucilage matrix and the parent cell in seed coat epidermal cells. We propose that mucilage remains attached to the seed coat through interactions between components in the seed mucilage and cellulose. Our data suggest that CESA2 and CESA9 serve in radial wall reinforcement, as does CESA5, but CESA5 also functions in mucilage biosynthesis. These data suggest unique roles for different CESA subunits in one cell type and illustrate a complex role for cellulose biosynthesis in plant developmental biology.
When a Day Makes a Difference. Interpreting Data from Endoplasmic Reticulum-Targeted Green Fluorescent Protein Fusions in Cells Grown in Suspension Culture
Publisher: Oxford University Press (OUP)
Date: 12-2199
DOI: 10.1104/PP.010840
Higher plant calreticulins have acquired specialized functions in arabidopsis
Publisher: Public Library of Science (PLoS)
Date: 28-06-2010
Expression atlas and comparative coexpression network analyses reveal important genes involved in the formation of lignified cell wall in Brachypodium distachyon
Publisher: Wiley
Date: 15-06-2017
DOI: 10.1111/NPH.14635
Abstract: While Brachypodium distachyon (Brachypodium) is an emerging model for grasses, no expression atlas or gene coexpression network is available. Such tools are of high importance to provide insights into the function of Brachypodium genes. We present a detailed Brachypodium expression atlas, capturing gene expression in its major organs at different developmental stages. The data were integrated into a large‐scale coexpression database ( www.gene2function.de ), enabling identification of duplicated pathways and conserved processes across 10 plant species, thus allowing genome‐wide inference of gene function. We highlight the importance of the atlas and the platform through the identification of duplicated cell wall modules, and show that a lignin biosynthesis module is conserved across angiosperms. We identified and functionally characterised a putative ferulate 5‐hydroxylase gene through overexpression of it in Brachypodium, which resulted in an increase in lignin syringyl units and reduced lignin content of mature stems, and led to improved saccharification of the stem biomass. Our Brachypodium expression atlas thus provides a powerful resource to reveal functionally related genes, which may advance our understanding of important biological processes in grasses.
Long-term single-cell imaging and simulations of microtubules reveal principles behind wall patterning during proto-xylem development
Publisher: Springer Science and Business Media LLC
Date: 28-01-2021
DOI: 10.1038/S41467-021-20894-1
Abstract: Plants are the tallest organisms on Earth a feature sustained by solute-transporting xylem vessels in the plant vasculature. The xylem vessels are supported by strong cell walls that are assembled in intricate patterns. Cortical microtubules direct wall deposition and need to rapidly re-organize during xylem cell development. Here, we establish long-term live-cell imaging of single Arabidopsis cells undergoing proto-xylem trans -differentiation, resulting in spiral wall patterns, to understand microtubule re-organization. We find that the re-organization requires local microtubule de-stabilization in band-interspersing gaps. Using microtubule simulations, we recapitulate the process in silico and predict that spatio-temporal control of microtubule nucleation is critical for pattern formation, which we confirm in vivo. By combining simulations and live-cell imaging we further explain how the xylem wall-deficient and microtubule-severing KATANIN contributes to microtubule and wall patterning. Hence, by combining quantitative microscopy and modelling we devise a framework to understand how microtubule re-organization supports wall patterning.
Toward the Storage Metabolome: Profiling the Barley Vacuole
Publisher: Oxford University Press (OUP)
Date: 26-09-2011
Abstract: While recent years have witnessed dramatic advances in our capacity to identify and quantify an ever-increasing number of plant metabolites, our understanding of how metabolism is spatially regulated is still far from complete. In an attempt to partially address this question, we studied the storage metabolome of the barley (Hordeum vulgare) vacuole. For this purpose, we used highly purified vacuoles isolated by silicon oil centrifugation and compared their metabolome with that found in the mesophyll protoplast from which they were derived. Using a combination of gas chromatography-mass spectrometry and Fourier transform-mass spectrometry, we were able to detect 59 (primary) metabolites for which we know the exact chemical structure and a further 200 (secondary) metabolites for which we have strong predicted chemical formulae. Taken together, these metabolites comprise amino acids, organic acids, sugars, sugar alcohols, shikimate pathway intermediates, vitamins, phenylpropanoids, and flavonoids. Of the 259 putative metabolites, some 12 were found exclusively in the vacuole and 34 were found exclusively in the protoplast, while 213 were common in both s les. When analyzed on a quantitative basis, however, there is even more variance, with more than 60 of these compounds being present above the detection limit of our protocols. The combined data were also analyzed with respect to the tonoplast proteome in an attempt to infer specificities of the transporter proteins embedded in this membrane. Following comparison with recent observations made using nonaqueous fractionation of Arabidopsis (Arabidopsis thaliana), we discuss these data in the context of current models of metabolic compartmentation in plants.
Diverging functions among calreticulin isoforms in higher plants
Publisher: Informa UK Limited
Date: 06-2011
Inferring gene functions through dissection of relevance networks: interleaving the intra- and inter-species views
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2MB25089F
Abstract: Inference of accurate gene annotations requires integration of existing biological knowledge, structured in a form of ontology, with data from transcriptomics high-throughput technologies. This undertaking requires developing algorithms that integrate genome-scale data, even for model organisms. Gene relevance networks have emerged as a powerful representative of the structure of the data. Such networks can be used for intra-species transfer of gene annotations following the guilt-by-association principle. An analogous principle can serve as a basis for inter-species transfer of gene annotations by comparing well-defined subnetworks. In this review, we compare and contrast the concepts of relevance and proximity networks and briefly review the concept of semantic similarity. We then provide a detailed account of quantitative guilt-by-association inference in the setting of genome-scale relevance networks. Moreover, we systematically survey the existing network-based approaches for automated gene function annotation and categorize them under one umbrella in terms of employed methodology. Furthermore, we discuss suitable data selection strategies required for deriving meaningful and unbiased genome-scale networks from large transcriptomics compendia. Lastly, by simulating gene function prediction with a classical network-based algorithm, we show how the number of genes of unknown function influences prediction within a species and pinpoint the need and the requirements for inter-species knowledge transfer.
POM-POM2/CELLULOSE SYNTHASE INTERACTING1 Is Essential for the Functional Association of Cellulose Synthase and Microtubules inArabidopsis
Publisher: Oxford University Press (OUP)
Date: 2012
Abstract: In plants, regulation of cellulose synthesis is fundamental for morphogenesis and plant growth. Cellulose is synthesized at the plasma membrane, and the orientation of synthesis is guided by cortical microtubules however, the guiding mechanism is currently unknown. We show that the conditional root elongation pom2 mutants are impaired in cell elongation, fertility, and microtubule-related functions. Map-based cloning of the POM-POM2 locus revealed that it is allelic to CELLULOSE SYNTHASE INTERACTING1 (CSI1). Fluorescently tagged POM2/CSI1s associated with both plasma membrane–located cellulose synthases (CESAs) and post-Golgi CESA-containing compartments. Interestingly, while CESA insertions coincided with cortical microtubules in the pom2/csi1 mutants, the microtubule-defined movement of the CESAs was significantly reduced in the mutant. We propose that POM2/CSI1 provides a scaffold between the CESAs and cortical microtubules that guide cellulose synthesis.
The cell biology of primary cell walls during salt stress
Publisher: Oxford University Press (OUP)
Date: 23-09-2022
Abstract: Salt stress simultaneously causes ionic toxicity, osmotic stress, and oxidative stress, which directly impact plant growth and development. Plants have developed numerous strategies to adapt to saline environments. Whereas some of these strategies have been investigated and exploited for crop improvement, much remains to be understood, including how salt stress is perceived by plants and how plants coordinate effective responses to the stress. It is, however, clear that the plant cell wall is the first contact point between external salt and the plant. In this context, significant advances in our understanding of halotropism, cell wall synthesis, and integrity surveillance, as well as salt-related cytoskeletal rearrangements, have been achieved. Indeed, molecular mechanisms underpinning some of these processes have recently been elucidated. In this review, we aim to provide insights into how plants respond and adapt to salt stress, with a special focus on primary cell wall biology in the model plant Arabidopsis thaliana.
Rice transcription factor MADS32 regulates floral patterning through interactions with multiple floral homeotic genes
Publisher: Oxford University Press (OUP)
Date: 18-12-2020
DOI: 10.1093/JXB/ERAA588
Abstract: Floral patterning is regulated by intricate networks of floral identity genes. The peculiar MADS32 subfamily genes, absent in eudicots but prevalent in monocots, control floral organ identity. However, how the MADS32 family genes interact with other floral homeotic genes during flower development is mostly unknown. We show here that the rice homeotic transcription factor OsMADS32 regulates floral patterning by interacting synergistically with E class protein OsMADS6 in a dosage-dependent manner. Furthermore, our results indicate important roles for OsMADS32 in defining stamen, pistil, and ovule development through physical and genetic interactions with OsMADS1, OsMADS58, and OsMADS13, and in specifying floral meristem identity with OsMADS6, OsMADS3, and OsMADS58, respectively. Our findings suggest that OsMADS32 is an important factor for floral meristem identity maintenance and that it integrates the action of other MADS-box homeotic proteins to sustain floral organ specification and development in rice. Given that OsMADS32 is an orphan gene and absent in eudicots, our data substantially expand our understanding of flower development in plants.
A Golgi UDP-GlcNAc transporter delivers substrates for N-linked glycans and sphingolipids
Publisher: Springer Science and Business Media LLC
Date: 17-09-2018
DOI: 10.1038/S41477-018-0235-5
Abstract: Glycosylation requires activated glycosyl donors in the form of nucleotide sugars to drive processes such as post-translational protein modifications and glycolipid and polysaccharide biosynthesis. Most of these reactions occur in the Golgi, requiring cytosolic-derived nucleotide sugars, which need to be actively transferred into the Golgi lumen by nucleotide sugar transporters. We identified a Golgi-localized nucleotide sugar transporter from Arabidopsis thaliana with affinity for UDP-N-acetyl-D-glucosamine (UDP-GlcNAc) and assigned it UDP-GlcNAc transporter 1 (UGNT1). Profiles of N-glycopeptides revealed that plants carrying the ugnt1 loss-of-function allele are virtually devoid of complex and hybrid N-glycans. Instead, the N-glycopeptide population from these alleles exhibited high-mannose structures, representing structures prior to the addition of the first GlcNAc in the Golgi. Concomitantly, sphingolipid profiling revealed that the biosynthesis of GlcNAc-containing glycosyl inositol phosphorylceramides (GIPCs) is also reliant on this transporter. By contrast, plants carrying the loss-of-function alleles affecting ROCK1, which has been reported to transport UDP-GlcNAc and UDP-N-acetylgalactosamine, exhibit no changes in N-glycan or GIPC profiles. Our findings reveal that plants contain a single UDP-GlcNAc transporter that delivers an essential substrate for the maturation of N-glycans and the GIPC class of sphingolipids.
Another brick in the wall: An inducible secondary wall system reveals how most plant biomass is synthesized
Publisher: American Association for the Advancement of Science (AAAS)
Date: 09-10-2015
Abstract: An inducible secondary wall system reveals how most plant biomass is synthesized [Also see Report by Watanabe et al. ]
Cell Wall Biology: Dual Control of Cellulose Synthase Guidance
Publisher: Elsevier BV
Date: 03-2020
Salt-Related MYB1 Coordinates Abscisic Acid Biosynthesis and Signaling during Salt Stress in Arabidopsis
Publisher: Oxford University Press (OUP)
Date: 04-08-2015
DOI: 10.1104/PP.15.00962
Cellulose biosynthesis inhibitor isoxaben causes nutrient-dependent and tissue-specific Arabidopsis phenotypes
Publisher: Oxford University Press (OUP)
Date: 12-10-2023
The Arabidopsis irregular xylem8 Mutant Is Deficient in Glucuronoxylan and Homogalacturonan, Which Are Essential for Secondary Cell Wall Integrity
Publisher: Oxford University Press (OUP)
Date: 2007
Abstract: The secondary cell wall in higher plants consists mainly of cellulose, lignin, and xylan and is the major component of biomass in many species. The Arabidopsis thaliana irregular xylem8 (irx8) mutant is dwarfed and has a significant reduction in secondary cell wall thickness. IRX8 belongs to a subgroup of glycosyltransferase family 8 called the GAUT1-related gene family, whose members include GAUT1, a homogalacturonan galacturonosyltransferase, and GAUT12 (IRX8). Here, we use comparative cell wall analyses to show that the irx8 mutant contains significantly reduced levels of xylan and homogalacturonan. Immunohistochemical analyses confirmed that the level of xylan was significantly reduced in the mutant. Structural fingerprinting of the cell wall polymers further revealed that irx8 is deficient in glucuronoxylan. To explore the biological function of IRX8, we crossed irx8 with irx1 (affecting cellulose synthase 8). The homozygous irx1 irx8 exhibited severely dwarfed phenotypes, suggesting that IRX8 is essential for cell wall integrity during cellulose deficiency. Taken together, the data presented show that IRX8 affects the level of glucuronoxylan and homogalacturonan in higher plants and that IRX8 provides an important link between the xylan polymer and the secondary cell wall matrix and directly affects secondary cell wall integrity.
Tricarboxylic Acid Cycle Activity Regulates Tomato Root Growth via Effects on Secondary Cell Wall Production
Publisher: Oxford University Press (OUP)
Date: 29-01-2010
Abstract: Transgenic tomato (Solanum lycopersicum ‘Moneymaker’) plants independently expressing fragments of various genes encoding enzymes of the tricarboxylic acid cycle in antisense orientation have previously been characterized as exhibiting altered root growth. In this study, we evaluate the rates of respiration of roots from these lines in addition to determining their total dry weight accumulation. Given that these features were highly correlated, we decided to carry out an evaluation of the cell wall composition in the transformants that revealed a substantial reduction in cellulose. Since the bulk of cellulose is associated with the secondary cell walls in roots, we reasoned that the transformants most likely were deficient in secondary wall cellulose production. Consistent with these findings, cross-sections of the root collar (approximately 15 mm from the junction between root and stem) displayed reduced lignified secondary cell walls for the transformants. In contrast, cell and cell wall patterning displayed no differences in elongating cells close to the root tip. To further characterize the modified cell wall metabolism, we performed feeding experiments in which we incubated excised root tips in [U-14C]glucose in the presence or absence of phosphonate inhibitors of the reaction catalyzed by 2-oxoglutarate dehydrogenase. Taken together, the combined results suggest that restriction of root respiration leads to a deficit in secondary cell wall synthesis. These data are discussed in the context of current models of biomass partitioning and plant growth.
Diversity of the protein disulfide isomerase family: Identification of breast tumor induced Hag2 and Hag3 as novel members of the protein family
Publisher: Elsevier BV
Date: 09-2005
The companion of cellulose synthase 1 confers salt tolerance through a Tau-like mechanism in plants
Publisher: Springer Science and Business Media LLC
Date: 20-02-2019
DOI: 10.1038/S41467-019-08780-3
Abstract: Microtubules are filamentous structures necessary for cell ision, motility and morphology, with dynamics critically regulated by microtubule-associated proteins (MAPs). Here we outline the molecular mechanism by which the MAP, COMPANION OF CELLULOSE SYNTHASE1 (CC1), controls microtubule bundling and dynamics to sustain plant growth under salt stress. CC1 contains an intrinsically disordered N-terminus that links microtubules at evenly distributed points through four conserved hydrophobic regions. By NMR and live cell analyses we reveal that two neighboring residues in the first hydrophobic binding motif are crucial for the microtubule interaction. The microtubule-binding mechanism of CC1 is reminiscent to that of the prominent neuropathology-related protein Tau, indicating evolutionary convergence of MAP functions across animal and plant cells.
Xylan-based nanocompartments orchestrate plant vessel wall patterning
Publisher: Springer Science and Business Media LLC
Date: 22-03-2022
DOI: 10.1038/S41477-022-01113-1
Abstract: Nanoclustering of biomacromolecules allows cells to efficiently orchestrate biological processes. The plant cell wall is a highly organized polysaccharide network but is heterogeneous in chemistry and structure. However, polysaccharide-based nanocompartments remain ill-defined. Here, we identify a xylan-rich nanodomain at pit borders of xylem vessels. We show that these nanocompartments maintain distinct wall patterns by anchoring cellulosic nanofibrils at the pit borders, critically supporting vessel robustness, water transport and leaf transpiration. The nanocompartments are produced by the activity of IRREGULAR XYLEM (IRX)10 and its homologues, which we show are de novo xylan synthases. Our study hence outlines a mechanism of how xylans are synthesized, how they assemble into nanocompartments and how the nanocompartments sustain cell wall pit patterning to support efficient water transport throughout the plant body.
Fluorescent cytoskeletal markers reveal associations between the actin and microtubule cytoskeleton in rice cells
Publisher: The Company of Biologists
Date: 15-06-2022
DOI: 10.1242/DEV.200415
Abstract: Rice (Oryza sativa) is one of our main food crops, feeding ∼3.5 billion people worldwide. An increasing number of studies note the importance of the cytoskeleton, including actin filaments and microtubules, in rice development and environmental responses. Yet, reliable in vivo cytoskeleton markers are lacking in rice, which limits our knowledge of cytoskeletal functions in living cells. Therefore, we generated bright fluorescent marker lines of the actin and microtubule cytoskeletons in rice, suitable for live-cell imaging in a wide variety of rice tissues. Using these lines, we show that actin bundles and microtubules engage and co-function during pollen grain development, how the cytoskeletal components are coordinated during root cell development, and that the actin cytoskeleton is robust and facilitates microtubule responses during salt stress. Hence, we conclude that our cytoskeletal marker lines, highlighted by our findings of cytoskeletal associations and dynamics, will substantially further future investigations in rice biology.
Related Organisations
Max Planck Institute For Molecular Plant Physiology
Location: Germany
Carnegie Institution For Science Department Of Plant Biology
Location: United States of America
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View Funded ActivityLinkage Infrastructure, Equipment And Facilities - Grant ID: LE160100008
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