Matthew Gilliham

Transcriptional variation is associated with differences in shoot sodium accumulation in distinct barley varieties

Publisher: Elsevier BV

Date: 10-2019

DOI: 10.1016/J.ENVEXPBOT.2019.103812

Role of TaALMT1 malate‐GABA transporter in alkaline pH tolerance of wheat

Publisher: Wiley

Date: 20-08-2020

DOI: 10.1111/PCE.13845

A single nucleotide substitution in TaHKT1;5‐D controls shoot Na+ accumulation in bread wheat

Publisher: Wiley

Date: 22-07-2020

DOI: 10.1111/PCE.13841

Evolution of chloroplast retrograde signaling facilitates green plant adaptation to land

Publisher: Proceedings of the National Academy of Sciences

Date: 25-02-2019

DOI: 10.1073/PNAS.1812092116

Abstract: Chloroplast retrograde signaling networks are vital for chloroplast biogenesis, operation, and signaling, including excess light and drought stress signaling. To date, retrograde signaling has been considered in the context of land plant adaptation, but not regarding the origin and evolution of signaling cascades linking chloroplast function to stomatal regulation. We show that key elements of the chloroplast retrograde signaling process, the nucleotide phosphatase (SAL1) and 3′-phosphoadenosine-5′-phosphate (PAP) metabolism, evolved in streptophyte algae—the algal ancestors of land plants. We discover an early evolution of SAL1-PAP chloroplast retrograde signaling in stomatal regulation based on conserved gene and protein structure, function, and enzyme activity and transit peptides of SAL1s in species including flowering plants, the fern Ceratopteris richardii , and the moss Physcomitrella patens . Moreover, we demonstrate that PAP regulates stomatal closure via secondary messengers and ion transport in guard cells of these erse lineages. The origin of stomata facilitated gas exchange in the earliest land plants. Our findings suggest that the conquest of land by plants was enabled by rapid response to drought stress through the deployment of an ancestral SAL1-PAP signaling pathway, intersecting with the core abscisic acid signaling in stomatal guard cells.

Transcriptomics on small samples.

Publisher: Humana Press

Date: 2012

DOI: 10.1007/978-1-61779-986-0_22

Abstract: Interrogating the cell-specific transcriptome forms an important component of understanding the role that specific cells play in assisting a plant to overcome abiotic stress. Among the challenges arising when extracting RNA from in idual plant cells are: the isolation of pure cell populations the small yield of material when isolating specific cell types, and ensuring an accurate representation of the transcriptome from each cell type after lification of RNA. Here we describe two approaches for isolating RNA from specific cell types-single cell s ling and analysis (SiCSA) and laser capture microdissection. Isolated RNA can then be directly s led qualitatively using reverse transcription PCR (RT-PCR) or lified for profiling -multiple specific genes using quantitative RT-PCR and genome-wide transcript analyses.

Measurement of differential cross-sections of a single top quark produced in association with a W boson at $$\sqrt{s}={13}{\text {

Publisher: Springer Science and Business Media LLC

Date: 03-2018

DOI: 10.1140/EPJC/S10052-018-5649-8

Search for a heavy Higgs boson decaying into a Z boson and another heavy Higgs boson in the ℓℓbb final state in pp collisions at

Publisher: Elsevier BV

Date: 08-2018

DOI: 10.1016/J.PHYSLETB.2018.07.006

The case for evidence‐based policy to support stress‐resilient cropping systems

Publisher: Wiley

Date: 02-2017

DOI: 10.1002/FES3.104

Chloroplast function and ion regulation in plants growing on saline soils: lessons from halophytes

Publisher: Oxford University Press (OUP)

Date: 02-05-2017

DOI: 10.1093/JXB/ERX142

Abstract: Salt stress impacts multiple aspects of plant metabolism and physiology. For instance it inhibits photosynthesis through stomatal limitation, causes excessive accumulation of sodium and chloride in chloroplasts, and disturbs chloroplast potassium homeostasis. Most research on salt stress has focused primarily on cytosolic ion homeostasis with few studies of how salt stress affects chloroplast ion homeostasis. This review asks the question whether membrane-transport processes and ionic relations are differentially regulated between glycophyte and halophyte chloroplasts and whether this contributes to the superior salt tolerance of halophytes. The available literature indicates that halophytes can overcome stomatal limitation by switching to CO2 concentrating mechanisms and increasing the number of chloroplasts per cell under saline conditions. Furthermore, salt entry into the chloroplast stroma may be critical for grana formation and photosystem II activity in halophytes but not in glycophytes. Salt also inhibits some stromal enzymes (e.g. fructose-1,6-bisphosphatase) to a lesser extent in halophyte species. Halophytes accumulate more chloride in chloroplasts than glycophytes and appear to use sodium in functional roles. We propose the molecular identities of candidate transporters that move sodium, chloride and potassium across chloroplast membranes and discuss how their operation may regulate photochemistry and photosystem I and II activity in chloroplasts.

Cytosolic GABA inhibits anion transport by wheat ALMT1.

Publisher: Wiley

Date: 03-11-2020

DOI: 10.1111/NPH.16238

Abstract: Anion transport by aluminium-activated malate transporter (ALMT) proteins is negatively regulated by gamma-aminobutyric acid (GABA), which increases in concentration during stress. Here, the interaction between GABA and wheat (Triticum aestivum, Ta) TaALMT1 heterologously-expressed in Xenopus laevis oocytes was investigated. GABA inhibited anion transport by TaALMT1 in membrane patches from the cytosolic, not extracellular membrane face, via a reduction in open probability (NP

Postveraison Leaf Removal Does Not Consistently Delay Ripening in Semillon and Shiraz in a Hot Australian Climate

Publisher: American Society for Enology and Viticulture

Date: 07-06-2019

DOI: 10.5344/AJEV.2019.18103

From Macrocrystals to Microcrystals: A Strategy for Membrane Protein Serial Crystallography

Publisher: Elsevier BV

Date: 09-2017

DOI: 10.1016/J.STR.2017.07.002

Abstract: Serial protein crystallography was developed at X-ray free-electron lasers (XFELs) and is now also being applied at storage ring facilities. Robust strategies for the growth and optimization of microcrystals are needed to advance the field. Here we illustrate a generic strategy for recovering high-density homogeneous s les of microcrystals starting from conditions known to yield large (macro) crystals of the photosynthetic reaction center of Blastochloris viridis (RC

The Regulation of Anion Loading to the Maize Root Xylem  

Publisher: Oxford University Press (OUP)

Date: 03-2005

DOI: 10.1104/PP.104.054056

Abstract: The regulation of anion loading to the shoot in maize (Zea mays) was investigated via an electrophysiological characterization of ion conductances in protoplasts isolated from the root stele. Two distinct anion conductances were identified. In protoplasts from well-watered plants, Z. mays xylem-parenchyma quickly-activating anion conductance (Zm-X-QUAC) was the most prevalent conductance and is likely to load the majority of NO3 − and Cl− ions to the xylem in nonstressed conditions. Z. mays xylem-parenchyma inwardly-rectifying anion conductance was found at a lower frequency in protoplasts from well-watered plants than Zm-X-QUAC, was much smaller in magnitude in all observed conditions, and is unlikely to be such a major pathway for anion loading into the xylem. Activity of Z. mays xylem-parenchyma inwardly-rectifying anion conductance increased following a water stress prior to protoplast isolation, but the activity of the putative major anion-loading pathway, Zm-X-QUAC, decreased. Addition of abscisic acid (ABA) to protoplasts from well-watered plants also inhibited Zm-X-QUAC activity within minutes, as did a high free Ca2+concentration in the pipette. ABA was also seen to activate a Ca2+-permeable conductance (Z. mays xylem-parenchyma hyperpolarization activated cation conductance) in protoplasts from well-watered plants. It is postulated that the inhibition of anion loading into the xylem (an important response to a water stress) due to down-regulation of Zm-X-QUAC activity is mediated by an ABA-mediated rise in free cytosolic Ca2+.

Linking Metabolism to Membrane Signaling: The GABA-Malate Connection.

Publisher: Elsevier BV

Date: 04-2015

DOI: 10.1016/J.TPLANTS.2015.11.011

Abstract: γ-Aminobutyric acid (GABA) concentration increases rapidly in tissues when plants encounter abiotic or biotic stress, and GABA manipulation affects growth. This, coupled to GABA's well-described role as a neurotransmitter in mammals, led to over a decade of speculation that GABA is a signal in plants. The discovery of GABA-regulated anion channels in plants provides compelling mechanistic proof that GABA is a legitimate plant-signaling molecule. Here we examine research avenues unlocked by this finding and propose that these plant 'GABA receptors' possess novel properties ideally suited to translating changes in metabolic status into physiological responses. Specifically, we suggest they have a role in signaling altered cycling of tricarboxylic acid (TCA) intermediates during stress via eliciting changes in electrical potential differences across membranes.

A Grain of Salt

Publisher: Cold Spring Harbor Laboratory

Date: 23-01-2020

DOI: 10.1101/2020.01.23.916742

Abstract: We quantified grain sodium (Na + ) content across a barley GWAS panel grown under optimal conditions. We identified a strong association with a region containing two low and one high Na + accumulating haplotypes of a Class 1 HIGH-AFFINITY POTASSIUM TRANSPORTER (HKT1 ) known to be involved in regulating plant Na + homeostasis. The haplotypes exhibited an average 1.8-fold difference in grain Na + content. We show that an L189P substitution disrupts Na + transport in the high Na + lines, disturbs the plasma membrane localisation typical of HKT1 and induces a conformational change in the protein predicted to compromise function. Under NaCl stress, lines containing P189 accumulate high levels of Na + , but show no significant difference in biomass. P189 increases in frequency from wild-species to elite cultivars leading us to speculate that the compromised haplotype is undergoing directional selection possibly due to the value of Na + as a functional nutrient in non-saline environments.

Wine terroir and the soil microbiome: an amplicon sequencing–based assessment of the Barossa Valley and its sub-regions

Publisher: Cold Spring Harbor Laboratory

Date: 12-08-2020

DOI: 10.1101/2020.08.12.246447

Abstract: Soil is an important factor that contributes to the uniqueness of a wine produced by vines grown in specific conditions. Recent data shows that the composition, ersity and function of soil microbial communities may play important roles in determining wine quality and indirectly affect its economic value. Here, we evaluated the impact of environmental variables on the soil microbiomes of 22 Barossa Valley vineyard sites based on the 16S rRNA gene hypervariable region 4. In this study, we report that environmental heterogeneity (soil plant-available P content, elevation, rainfall, temperature, spacing between row and spacing between vine) caused more microbial dissimilarity than geographic distance. Vineyards located in cooler and wetter regions showed lower beta ersity and a higher ratio of dominant taxa. Differences in microbial community composition were significantly associated with differences in fruit traits and in wine chemical and metabolomic profiles, highlighting the potential influence of microbial communities on the phenotype of grapevines. Our results suggest that environmental factors affect wine terroir, and this may be mediated by changes in microbial structure, thus providing a basic understanding of how growing conditions affect interactions between plants and their soil microbiomes.

The Na + transporter, TaHKT1;5-D, limits shoot Na + accumulation in bread wheat

Publisher: Wiley

Date: 10-2014

DOI: 10.1111/TPJ.12651

Abstract: Bread wheat (Triticum aestivum L.) has a major salt tolerance locus, Kna1, responsible for the maintenance of a high cytosolic K(+) /Na(+) ratio in the leaves of salt stressed plants. The Kna1 locus encompasses a large DNA fragment, the distal 14% of chromosome 4DL. Limited recombination has been observed at this locus making it difficult to map genetically and identify the causal gene. Here, we decipher the function of TaHKT1 -D, a candidate gene underlying the Kna1 locus. Transport studies using the heterologous expression systems Saccharomyces cerevisiae and Xenopus laevis oocytes indicated that TaHKT1 -D is a Na(+) -selective transporter. Transient expression in Arabidopsis thaliana mesophyll protoplasts and in situ polymerase chain reaction indicated that TaHKT1 -D is localised on the plasma membrane in the wheat root stele. RNA interference-induced silencing decreased the expression of TaHKT1 -D in transgenic bread wheat lines which led to an increase in the Na(+) concentration in the leaves. This indicates that TaHKT1 -D retrieves Na(+) from the xylem vessels in the root and has an important role in restricting the transport of Na(+) from the root to the leaves in bread wheat. Thus, TaHKT1 -D confers the essential salinity tolerance mechanism in bread wheat associated with the Kna1 locus via shoot Na(+) exclusion and is critical in maintaining a high K(+) /Na(+) ratio in the leaves. These findings show there is potential to increase the salinity tolerance of bread wheat by manipulation of HKT1 genes.

Aluminum-Activated Malate Transporters Can Facilitate GABA Transport

Publisher: Oxford University Press (OUP)

Date: 04-04-2018

DOI: 10.1105/TPC.17.00864

Manipulating exudate composition from root apices shapes the microbiome throughout the root system

Publisher: Oxford University Press (OUP)

Date: 22-07-2021

DOI: 10.1093/PLPHYS/KIAB337

Abstract: Certain soil microorganisms can improve plant growth, and practices that encourage their proliferation around the roots can boost production and reduce reliance on agrochemicals. The beneficial effects of the microbial inoculants currently used in agriculture are inconsistent or short-lived because their persistence in soil and on roots is often poor. A complementary approach could use root exudates to recruit beneficial microbes directly from the soil and encourage inoculant proliferation. However, it is unclear whether the release of common organic metabolites can alter the root microbiome in a consistent manner and if so, how those changes vary throughout the whole root system. In this study, we altered the expression of transporters from the ALUMINUM-ACTIVATED MALATE TRANSPORTER and the MULTIDRUG AND TOXIC COMPOUND EXTRUSION families in rice (Oryza sativa L.) and wheat (Triticum aestivum L.) and tested how the subsequent release of their substrates (simple organic anions, including malate, citrate, and γ-amino butyric acid) from root apices affected the root microbiomes. We demonstrate that these exudate compounds, separately and in combination, significantly altered microbiome composition throughout the root system. However, the root type (seminal or nodal), position along the roots (apex or base), and soil type had a greater influence on microbiome structure than the exudates. These results reveal that the root microbiomes of important cereal species can be manipulated by altering the composition of root exudates, and support ongoing attempts to improve plant production by manipulating the root microbiome.

High affinity Na+ transport by wheat HKT1;5 is blocked by K+

Publisher: Cold Spring Harbor Laboratory

Date: 12-03-2018

DOI: 10.1101/280453

Abstract: The wheat sodium transporters TmHKT1 -A and TaHKT1 -D are encoded by genes underlying major shoot Na + exclusion loci Nax2 and Kna1 from Triticum monococcum (Tm) and Triticum aestivum (Ta), respectively. In contrast to HKT2 transporters that have been shown to exhibit high affinity K + -dependent Na + transport, HKT1 proteins have, with one exception, only been shown to catalyse low affinity Na + transport and no K + transport. Here, using heterologous expression in Xenopus laevis oocytes we show that both TmHKT1 -A and TaHKT1 -D encode dual (high and low) affinity Na + -transporters with the high-affinity component being abolished when external K + is in excess of external Na + . Based on 3-D structural modelling we propose that tighter binding of K + , compared to that of Na + in the selectivity filter region by means of additional van der Waals forces, explains the K + block at the molecular level. The low-affinity component for Na + transport of TmHKT1 -A had a lower K m than that of TaHKT1 -D and was less sensitive to external K + . We propose that these properties underpin the improvements in shoot Na + -exclusion and crop plant salt tolerance following the introgression of TmHKT1 -A into erse wheat backgrounds.

The evolutionary origin of CIPK16: A gene involved in enhanced salt tolerance

Publisher: Elsevier BV

Date: 07-2016

DOI: 10.1016/J.YMPEV.2016.03.031

Abstract: Calcineurin B-like protein interacting protein kinases (CIPKs) are key regulators of pre-transcriptional and post-translational responses to abiotic stress. Arabidopsis thaliana CIPK16 (AtCIPK16) was identified from a forward genetic screen as a gene that mediates lower shoot salt accumulation and improved salinity tolerance in Arabidopsis and transgenic barley. Here, we aimed to gain an understanding of the evolution of AtCIPK16, and orthologues of CIPK16 in other plant species including barley, by conducting a phylogenetic analysis of terrestrial plant species. The resulting protein sequence based phylogenetic trees revealed a single clade that included AtCIPK16 along with two segmentally duplicated CIPKs, AtCIPK5 and AtCIPK25. No monocots had proteins that fell into this clade instead the most closely related monocot proteins formed a group basal to the entire CIPK16, 5 and 25 clade. We also found that AtCIPK16 contains a core Brassicales specific indel and a putative nuclear localisation signal, which are synapomorphic characters of CIPK16 genes. In addition, we present a model that proposes the evolution of CIPK16, 5 and 25 clade.

Protocol: a fast and simple in situ PCR method for localising gene expression in plant tissue.

Publisher: Springer Science and Business Media LLC

Date: 18-09-2014

DOI: 10.1186/1746-4811-10-29

Tissue and regional expression patterns of dicistronic tRNA–mRNA transcripts in grapevine (Vitis vinifera) and their evolutionary co-appearance with vasculature in land plants

Publisher: Oxford University Press (OUP)

Date: 06-2021

DOI: 10.1038/S41438-021-00572-5

Abstract: Transfer RNAs (tRNA) are crucial adaptor molecules between messenger RNA (mRNA) and amino acids. Recent evidence in plants suggests that dicistronic tRNA-like structures also act as mobile signals for mRNA transcripts to move between distant tissues. Co-transcription is not a common feature in the plant nuclear genome and, in the few cases where polycistronic transcripts have been found, they include non-coding RNA species, such as small nucleolar RNAs and microRNAs. It is not known, however, the extent to which dicistronic transcripts of tRNA and mRNAs are expressed in field-grown plants, or the factors contributing to their expression. We analysed tRNA–mRNA dicistronic transcripts in the major horticultural crop grapevine ( Vitis vinifera ) using a novel pipeline developed to identify dicistronic transcripts from high-throughput RNA-sequencing data. We identified dicistronic tRNA–mRNA in leaf and berry s les from 22 commercial vineyards. Of the 124 tRNA genes that were expressed in both tissues, 18 tRNA were expressed forming part of 19 dicistronic tRNA–mRNAs. The presence and abundance of dicistronic molecules was tissue and geographic sub-region specific. In leaves, the expression patterns of dicistronic tRNA–mRNAs significantly correlated with tRNA expression, suggesting that their transcriptional regulation might be linked. We also found evidence of syntenic genomic arrangements of tRNAs and protein-coding genes between grapevine and Arabidopsis thaliana , and widespread prevalence of dicistronic tRNA–mRNA transcripts among vascular land plants but no evidence of these transcripts in non-vascular lineages. This suggests that the appearance of plant vasculature and tRNA–mRNA occurred concurrently during the evolution of land plants.

Statistical modeling of nitrogen‐dependent modulation of root system architecture in Arabidopsis thaliana

Publisher: Wiley

Date: 02-11-2015

DOI: 10.1111/JIPB.12433

Abstract: Plant root development is strongly affected by nutrient availability. Despite the importance of structure and function of roots in nutrient acquisition, statistical modeling approaches to evaluate dynamic and temporal modulations of root system architecture in response to nutrient availability have remained as widely open and exploratory areas in root biology. In this study, we developed a statistical modeling approach to investigate modulations of root system architecture in response to nitrogen availability. Mathematical models were designed for quantitative assessment of root growth and root branching phenotypes and their dynamic relationships based on hierarchical configuration of primary and lateral roots formulating the fishbone-shaped root system architecture in Arabidopsis thaliana. Time-series datasets reporting dynamic changes in root developmental traits on different nitrate or ammonium concentrations were generated for statistical analyses. Regression analyses unraveled key parameters associated with: (i) inhibition of primary root growth under nitrogen limitation or on ammonium (ii) rapid progression of lateral root emergence in response to ammonium and (iii) inhibition of lateral root elongation in the presence of excess nitrate or ammonium. This study provides a statistical framework for interpreting dynamic modulation of root system architecture, supported by meta-analysis of datasets displaying morphological responses of roots to erse nitrogen supplies.

Water transport & aquaporins in grapevine

Publisher: Springer Netherlands

Date: 2009

DOI: 10.1007/978-90-481-2305-6_4

Energy costs of salinity tolerance in crop plants

Publisher: Wiley

Date: 29-11-2019

DOI: 10.1111/NPH.15555

Enhancing crop yields through improvements in the efficiency of photosynthesis and respiration

Publisher: Wiley

Date: 17-11-2023

DOI: 10.1111/NPH.18545

Abstract: The rate with which crop yields per hectare increase each year is plateauing at the same time that human population growth and other factors increase food demand. Increasing yield potential () of crops is vital to address these challenges. In this review, we explore a component of that has yet to be optimised – that being improvements in the efficiency with which light energy is converted into biomass () via modifications to CO 2 fixed per unit quantum of light ( α ), efficiency of respiratory ATP production () and efficiency of ATP use (). For α , targets include changes in photoprotective machinery, ribulose bisphosphate carboxylase/oxygenase kinetics and photorespiratory pathways. There is also potential for to be increased via targeted changes to the expression of the alternative oxidase and mitochondrial uncoupling pathways. Similarly, there are possibilities to improve via changes to the ATP costs of phloem loading, nutrient uptake, futile cycles and/or protein/membrane turnover. Recently developed high‐throughput measurements of respiration can serve as a proxy for the cumulative energy cost of these processes. There are thus exciting opportunities to use our growing knowledge of factors influencing the efficiency of photosynthesis and respiration to create a step‐change in yield potential of globally important crops.

Chloride on the Move

Publisher: Elsevier BV

Date: 03-2017

DOI: 10.1016/J.TPLANTS.2016.12.004

Abstract: Chloride (Cl

Measurement of the production cross section of three isolated photons in pp collisions at

Publisher: Elsevier BV

Date: 06-2018

DOI: 10.1016/J.PHYSLETB.2018.03.057

Wheat grain yield on saline soils is improved by an ancestral Na+ transporter gene

Publisher: Springer Science and Business Media LLC

Date: 11-03-2012

DOI: 10.1038/NBT.2120

Abstract: The ability of wheat to maintain a low sodium concentration ([Na(+)]) in leaves correlates with improved growth under saline conditions. This trait, termed Na(+) exclusion, contributes to the greater salt tolerance of bread wheat relative to durum wheat. To improve the salt tolerance of durum wheat, we explored natural ersity in shoot Na(+) exclusion within ancestral wheat germplasm. Previously, we showed that crossing of Nax2, a gene locus in the wheat relative Triticum monococcum into a commercial durum wheat (Triticum turgidum ssp. durum var. Tamaroi) reduced its leaf [Na(+)] (ref. 5). Here we show that a gene in the Nax2 locus, TmHKT1 -A, encodes a Na(+)-selective transporter located on the plasma membrane of root cells surrounding xylem vessels, which is therefore ideally localized to withdraw Na(+) from the xylem and reduce transport of Na(+) to leaves. Field trials on saline soils demonstrate that the presence of TmHKT1 -A significantly reduces leaf [Na(+)] and increases durum wheat grain yield by 25% compared to near-isogenic lines without the Nax2 locus.

Heterodimerization of Arabidopsis calcium/proton exchangers contributes to regulation of guard cell dynamics and plant defense responses

Publisher: Oxford University Press (OUP)

Date: 22-06-2017

DOI: 10.1093/JXB/ERX209

Observation of Higgs boson production in association with a top quark pair at the LHC with the ATLAS detector

Publisher: Elsevier BV

Date: 09-2018

DOI: 10.1016/J.PHYSLETB.2018.07.035

High affinity Na+ transport by wheat HKT1;5 is blocked by K+

Publisher: Wiley

Date: 10-2020

DOI: 10.1002/PLD3.275

Grapevine and Arabidopsis cation-chloride cotransporters localise to the Golgi and trans-Golgi network and indirectly influence long-distance ion homeostasis and plant salt tolerance

Publisher: Oxford University Press (OUP)

Date: 16-09-2015

DOI: 10.1104/PP.15.00499

Cell-specific vacuolar calcium storage mediated by CAX1 regulates apoplastic calcium concentration, gas exchange, and plant productivity in Arabidopsis

Publisher: Oxford University Press (OUP)

Date: 2011

DOI: 10.1105/TPC.109.072769

Abstract: The physiological role and mechanism of nutrient storage within vacuoles of specific cell types is poorly understood. Transcript profiles from Arabidopsis thaliana leaf cells differing in calcium concentration ([Ca], epidermis & mM versus mesophyll & mM) were compared using a microarray screen and single-cell quantitative PCR. Three tonoplast-localized Ca2+ transporters, CAX1 (Ca2+/H+-antiporter), ACA4, and ACA11 (Ca2+-ATPases), were identified as preferentially expressed in Ca-rich mesophyll. Analysis of respective loss-of-function mutants demonstrated that only a mutant that lacked expression of both CAX1 and CAX3, a gene ectopically expressed in leaves upon knockout of CAX1, had reduced mesophyll [Ca]. Reduced capacity for mesophyll Ca accumulation resulted in reduced cell wall extensibility, stomatal aperture, transpiration, CO2 assimilation, and leaf growth rate increased transcript abundance of other Ca2+ transporter genes altered expression of cell wall–modifying proteins, including members of the pectinmethylesterase, expansin, cellulose synthase, and polygalacturonase families and higher pectin concentrations and thicker cell walls. We demonstrate that these phenotypes result from altered apoplastic free [Ca2+], which is threefold greater in cax1/cax3 than in wild-type plants. We establish CAX1 as a key regulator of apoplastic [Ca2+] through compartmentation into mesophyll vacuoles, a mechanism essential for optimal plant function and productivity.

Comparative physiology of elemental distributions in plants

Publisher: Oxford University Press (OUP)

Date: 21-04-2010

DOI: 10.1093/AOB/MCQ027

SLAH1, a homologue of the slow type anion channel SLAC1, modulates shoot Cl− accumulation and salt tolerance in Arabidopsis thaliana

Publisher: Oxford University Press (OUP)

Date: 23-06-2016

DOI: 10.1093/JXB/ERW237

Abstract: Salinity tolerance is correlated with shoot chloride (Cl–) exclusion in multiple crops, but the molecular mechanisms of long-distance Cl– transport are poorly defined. Here, we characterize the in planta role of AtSLAH1 (a homologue of the slow type anion channel-associated 1 (SLAC1)). This protein, localized to the plasma membrane of root stelar cells, has its expression reduced by salt or ABA, which are key predictions for a protein involved with loading Cl– into the root xylem. Artificial microRNA knockdown mutants of AtSLAH1 had significantly reduced shoot Cl− accumulation when grown under low Cl–, whereas shoot Cl– increased and the shoot nitrate/chloride ratio decreased following AtSLAH1 constitutive or stelar-specific overexpression when grown in high Cl–. In both sets of overexpression lines a significant reduction in shoot biomass over the null segregants was observed under high Cl– supply, but not low Cl– supply. Further in planta data showed AtSLAH3 overexpression increased the shoot nitrate/chloride ratio, consistent with AtSLAH3 favouring nitrate transport. Heterologous expression of AtSLAH1 in Xenopus laevis oocytes led to no detectible transport, suggesting the need for post-translational modifications for AtSLAH1 to be active. Our in planta data are consistent with AtSLAH1 having a role in controlling root-to-shoot Cl– transport.

GABA signalling in guard cells acts as a ‘stress memory’ to optimise plant water loss

Publisher: Cold Spring Harbor Laboratory

Date: 23-12-2019

DOI: 10.1101/2019.12.22.885160

Abstract: The non-protein amino acid γ-aminobutyric acid (GABA) has been proposed to be an ancient messenger for cellular communication conserved across biological kingdoms. GABA has well-defined signalling roles in animals however, whilst GABA accumulates in plants under stress it has not been determined if, how, where and when GABA acts as an endogenous plant signalling molecule. Here, we establish that endogenous GABA is a bona fide plant signal, acting via a mechanism not found in animals. GABA antagonises stomatal movement in response to opening and closing stimuli in multiple plant families including dicot and monocot crops. Using Arabidopsis thaliana , we show guard cell GABA production is necessary and sufficient to influence stomatal aperture, transpirational water loss and drought tolerance via inhibition of stomatal guard cell plasma membrane and tonoplast-localised anion transporters. This study proposes a novel role for GABA – as a ‘stress memory’ – opening new avenues for improving plant stress tolerance.

Global DNA Methylation Patterns Can Play a Role in Defining Terroir in Grapevine (Vitis vinifera cv. Shiraz)

Publisher: Frontiers Media SA

Date: 30-10-2017

DOI: 10.3389/FPLS.2017.01860

Barley sodium content is regulated by natural variants of the Na+ transporter HvHKT1;5

Publisher: Springer Science and Business Media LLC

Date: 22-05-2020

DOI: 10.1038/S42003-020-0990-5

Abstract: During plant growth, sodium (Na + ) in the soil is transported via the xylem from the root to the shoot. While excess Na + is toxic to most plants, non-toxic concentrations have been shown to improve crop yields under certain conditions, such as when soil K + is low. We quantified grain Na + across a barley genome-wide association study panel grown under non-saline conditions and identified variants of a Class 1 HIGH-AFFINITY-POTASSIUM-TRANSPORTER ( HvHKT1 )-encoding gene responsible for Na + content variation under these conditions. A leucine to proline substitution at position 189 (L189P) in HvHKT1 disturbs its characteristic plasma membrane localisation and disrupts Na + transport. Under low and moderate soil Na + , genotypes containing HvHKT1:5 P189 accumulate high concentrations of Na + but exhibit no evidence of toxicity. As the frequency of HvHKT1:5 P189 increases significantly in cultivated European germplasm, we cautiously speculate that this non-functional variant may enhance yield potential in non-saline environments, possibly by offsetting limitations of low available K + .

Fruit Calcium: Transport and Physiology

Publisher: Frontiers Media SA

Date: 29-04-2016

DOI: 10.3389/FPLS.2016.00569

Root cell wall solutions for crop plants in saline soils

Publisher: Elsevier BV

Date: 04-2018

DOI: 10.1016/J.PLANTSCI.2017.12.012

Abstract: The root growth of most crop plants is inhibited by soil salinity. Roots respond by modulating metabolism, gene expression and protein activity, which results in changes in cell wall composition, transport processes, cell size and shape, and root architecture. Here, we focus on the effects of salt stress on cell wall modifying enzymes, cellulose microfibril orientation and non-cellulosic polysaccharide deposition in root elongation zones, as important determinants of inhibition of root elongation, and highlight cell wall changes linked to tolerance to salt stressed and water limited roots. Salt stress induces changes in the wall composition of specific root cell types, including the increased deposition of lignin and suberin in endodermal and exodermal cells. These changes can benefit the plant by preventing water loss and altering ion transport pathways. We suggest that binding of Na

Tissue and regional expression patterns of dicistronic tRNA-mRNA transcripts in grapevine (Vitis vinifera) and their evolutionary co-appearance with vasculature in land plants

Publisher: Cold Spring Harbor Laboratory

Date: 13-04-2020

DOI: 10.1101/2020.04.13.039131

Abstract: Transfer RNAs (tRNA) are crucial adaptor molecules between messenger RNA (mRNA) and amino acids. Recent evidence in plants suggests that dicistronic tRNA-like structures also act as mobile signals for mRNA transcripts to move between distant tissues. Co-transcription is not a common feature in the plant nuclear genome and, in the few cases where polycistronic transcripts have been found, they include non-coding RNA species such as small nucleolar RNAs and microRNAs. It is not known, however, the extent to which dicistronic transcripts of tRNA and mRNAs are expressed in field-grown plants, or the factors contributing to their expression. We analysed tRNA-mRNA dicistronic transcripts in the major horticultural crop grapevine ( Vitis vinifera ) using a novel pipeline developed to identify dicistronic transcripts from high-throughput RNA sequencing data. We identified dicistronic tRNA-mRNA in leaf and berry s les from 22 commercial vineyards. Of the 124 tRNA genes that were expressed in both tissues, 18 tRNA were expressed forming part of 19 dicistronic tRNA-mRNAs. The presence and abundance of dicistronic molecules was tissue and geographic sub-region specific. In leaves, the expression patterns of dicistronic tRNA-mRNAs significantly correlated with tRNA expression, suggesting that their transcriptional regulation might be linked. We also found evidence of syntenic genomic arrangements of tRNAs and protein coding genes between grapevine and Arabidopsis thaliana , and widespread prevalence of dicistronic tRNA-mRNA transcripts among vascular land plants but no evidence of these transcripts in nonvascular lineages. This suggests that the appearance of plant vasculature and tRNA-mRNA occurred concurrently during the evolution of land plants.

Salinity tolerance of crops - what is the cost?

Publisher: Wiley

Date: 24-06-2015

DOI: 10.1111/NPH.13519

Abstract: Soil salinity reduces crop yield. The extent and severity of salt‐affected agricultural land is predicted to worsen as a result of inadequate drainage of irrigated land, rising water tables and global warming. The growth and yield of most plant species are adversely affected by soil salinity, but varied adaptations can allow some crop cultivars to continue to grow and produce a harvestable yield under moderate soil salinity. Significant costs are associated with saline soils: the economic costs to the farming community and the energy costs of plant adaptations. We briefly consider mechanisms of adaptation and highlight recent research ex les through a lens of their applicability to improving the energy efficiency of crops under saline field conditions. Contents Summary 668 I. Soil salinity and its economic costs 668 II. Mechanisms of plant adaptation to saline soil and potential energy costs 668 III. New insights into salinity tolerance mechanisms 670 IV. Better yield under nonsaline conditions equals better salt tolerance? 671 V. What does the future hold for stress tolerance research? 672 Acknowledgements 672 References 672

The function of the Medicago truncatula ZIP transporter MtZIP14 is linked to arbuscular mycorrhizal fungal colonization

Publisher: Wiley

Date: 29-01-2023

DOI: 10.1111/PCE.14545

Abstract: Soil micronutrient availability, including zinc (Zn), is a limiting factor for crop yield. Arbuscular mycorrhizal (AM) fungi can improve host plant growth and nutrition through the mycorrhizal pathway of nutrient uptake. Although the physiology of Zn uptake through the mycorrhizal pathway is well established, the identity of the related molecular components are unknown. Here, RNA‐seq analysis was used to identify genes differentially‐regulated by AM colonization and soil Zn concentration in roots of Medicago truncatula . The putative Zn transporter gene MtZIP14 was markedly up‐regulated in M. truncatula roots when colonized by Rhizophagus irregularis . MtZIP14 restored yeast growth under low Zn availability. Loss‐of‐function mutant plants ( mtzip14 ) had reduced shoot biomass compared to the wild‐type when colonized by AM fungi and grown under low and sufficient soil Zn concentration at high soil Zn concentration, there were no genotypic differences in shoot biomass. The vesicular and arbuscular colonization of roots was lower in the mtzip14 plants regardless of soil Zn concentration. We propose that MtZIP14 is linked to AM colonization in M. truncatula plants, with the possibility that MtZIP14 function with AM colonization is linked to plant Zn nutrition.

The sodium transporter encoded by the HKT1;2 gene modulates sodium/potassium homeostasis in tomato shoots under salinity

Publisher: Wiley

Date: 20-01-2017

DOI: 10.1111/PCE.12883

Abstract: Excessive soil salinity diminishes crop yield and quality. In a previous study in tomato, we identified two closely linked genes encoding HKT1‐like transporters, HKT1 1 and HKT1 2 , as candidate genes for a major quantitative trait locus ( kc7 . 1 ) related to shoot Na + /K + homeostasis – a major salt tolerance trait – using two populations of recombinant inbred lines (RILs). Here, we determine the effectiveness of these genes in conferring improved salt tolerance by using two near‐isogenic lines (NILs) that were homozygous for either the Solanum lycopersicum allele (NIL17) or for the Solanum cheesmaniae allele (NIL14) at both HKT1 loci transgenic lines derived from these NILs in which each HKT1 1 and HKT1 2 had been silenced by stable transformation were also used. Silencing of ScHKT1 2 and SlHKT1 2 altered the leaf Na + /K + ratio and caused hypersensitivity to salinity in plants cultivated under transpiring conditions, whereas silencing SlHKT1 1 / ScHKT1 1 had a lesser effect. These results indicate that HKT1 2 has the more significant role in Na + homeostasis and salinity tolerance in tomato.

GABA signalling modulates plant growth by directly regulating the activity of plant-specific anion transporters

Publisher: Springer Science and Business Media LLC

Date: 29-07-2015

DOI: 10.1038/NCOMMS8879

Abstract: The non-protein amino acid, gamma-aminobutyric acid (GABA) rapidly accumulates in plant tissues in response to biotic and abiotic stress, and regulates plant growth. Until now it was not known whether GABA exerts its effects in plants through the regulation of carbon metabolism or via an unidentified signalling pathway. Here, we demonstrate that anion flux through plant aluminium-activated malate transporter (ALMT) proteins is activated by anions and negatively regulated by GABA. Site-directed mutagenesis of selected amino acids within ALMT proteins abolishes GABA efficacy but does not alter other transport properties. GABA modulation of ALMT activity results in altered root growth and altered root tolerance to alkaline pH, acid pH and aluminium ions. We propose that GABA exerts its multiple physiological effects in plants via ALMT, including the regulation of pollen tube and root growth, and that GABA can finally be considered a legitimate signalling molecule in both the plant and animal kingdoms.

AtCIPK16 mediates salt stress through phytohormones and transcription factors

Publisher: Cold Spring Harbor Laboratory

Date: 18-02-2020

DOI: 10.1101/2020.02.17.953216

Abstract: Soil salinity causes large productivity losses for agriculture worldwide. “Next-generation crops” that can tolerate salt stress are required for the sustainability of global food production. Previous research in Arabidopsis thaliana aimed at uncovering novel factors underpinning improved plant salinity tolerance identified the protein kinase AtCIPK16. Overexpression of AtCIPK16 enhanced shoot Na + exclusion and increased biomass in both Arabidopsis and barley. Here, a comparative transcriptomic study on Arabidopsis lines expressing AtCIPK16 was conducted in the presence and absence of salt stress, using an RNA-Seq approach, complemented by AtCIPK16 interaction and localisation studies. We are now able to provide evidence for AtCIPK16 activity in the nucleus. Moreover, the results manifest the involvement of a transcription factor, AtTZF1, phytohormones and the ability to quickly reach homeostasis as components important for improving salinity tolerance in transgenics overexpressing AtCIPK16 . Furthermore, we suggest the possibility of both biotic and abiotic tolerance through AtCIPK16, and propose a model for the salt tolerance pathway elicited through AtCIPK16.

Channel-Like Characteristics of the Low-Affinity Barley Phosphate Transporter PHT1;6 When Expressed in Xenopus Oocytes

Publisher: Oxford University Press (OUP)

Date: 06-01-2010

DOI: 10.1104/PP.109.152009

Abstract: Remobilization of inorganic phosphate (Pi) within a plant is critical for sustaining growth and seed production under external Pi fluctuation. The barley (Hordeum vulgare) transporter HvPHT1 has been implicated in Pi remobilization. In this report, we expressed HvPHT1 in Xenopus laevis oocytes, allowing detailed characterization of voltage-dependent fluxes and currents induced by HvPHT1 . HvPHT1 increased efflux of Pi near oocyte resting membrane potentials, dependent on external Pi concentration. Time-dependent inward currents were observed when membrane potentials were more negative than −160 mV, which was consistent with nH+:HPO42− (n & 2) cotransport, based on simultaneous radiotracer and oocyte voltage cl ing, dependent upon Pi concentration gradient and pH. Time- and voltage-dependent inward currents through HvPHT1 were also observed for SO42−and to a lesser degree for NO3−Cl−but not for malate. Inward and outward currents showed linear dependence on the concentration of external HPO42−similar to low-affinity Pi transport in plant studies. The electrophysiological properties of HvPHT1 , which locates to the plasma membrane when expressed in onion (Allium cepa) epidermal cells, are consistent with its suggested role in the remobilization of Pi in barley plants.

GmSALT3, Which Confers Improved Soybean Salt Tolerance in the Field, Increases Leaf Cl- Exclusion Prior to Na+ Exclusion But Does Not Improve Early Vigor under Salinity

Publisher: Frontiers Media SA

Date: 30-09-2016

DOI: 10.3389/FPLS.2016.01485

Mapping of novel salt tolerance QTL in an Excalibur × Kukri doubled haploid wheat population

Publisher: Springer Science and Business Media LLC

Date: 30-07-2018

DOI: 10.1007/S00122-018-3146-Y

Abstract: Novel QTL for salinity tolerance traits have been detected using non-destructive and destructive phenotyping in bread wheat and were shown to be linked to improvements in yield in saline fields. Soil salinity is a major limitation to cereal production. Breeding new salt-tolerant cultivars has the potential to improve cereal crop yields. In this study, a doubled haploid bread wheat mapping population, derived from the bi-parental cross of Excalibur × Kukri, was grown in a glasshouse under control and salinity treatments and evaluated using high-throughput non-destructive imaging technology. Quantitative trait locus (QTL) analysis of this population detected multiple QTL under salt and control treatments. Of these, six QTL were detected in the salt treatment including one for maintenance of shoot growth under salinity ( QG (1 – 5) .asl - 7A ), one for leaf Na + exclusion ( QNa.asl - 7A ) and four for leaf K + accumulation ( QK.asl - 2B.1 , QK.asl - 2B.2 , QK.asl - 5A and QK:Na.asl - 6A ). The beneficial allele for QG (1 – 5) .asl - 7A (the maintenance of shoot growth under salinity) was present in six out of 44 mainly Australian bread and durum wheat cultivars. The effect of each QTL allele on grain yield was tested in a range of salinity concentrations at three field sites across 2 years. In six out of nine field trials with different levels of salinity stress, lines with alleles for Na + exclusion and/or K + maintenance at three QTL ( QNa.asl - 7A , QK.asl - 2B.2 and QK:Na.asl - 6A ) excluded more Na + or accumulated more K + compared to lines without these alleles. Importantly, the QK.asl - 2B.2 allele for higher K + accumulation was found to be associated with higher grain yield at all field sites. Several alleles at other QTL were associated with higher grain yields at selected field sites.

Calcium delivery and storage in plant leaves: Exploring the link with water flow

Publisher: Oxford University Press (OUP)

Date: 04-2011

DOI: 10.1093/JXB/ERR111

Abstract: Calcium (Ca) is a unique macronutrient with erse but fundamental physiological roles in plant structure and signalling. In the majority of crops the largest proportion of long-distance calcium ion (Ca(2+)) transport through plant tissues has been demonstrated to follow apoplastic pathways, although this paradigm is being increasingly challenged. Similarly, under certain conditions, apoplastic pathways can dominate the proportion of water flow through plants. Therefore, tissue Ca supply is often found to be tightly linked to transpiration. Once Ca is deposited in vacuoles it is rarely redistributed, which results in highly transpiring organs amassing large concentrations of Ca ([Ca]). Meanwhile, the nutritional flow of Ca(2+) must be regulated so it does not interfere with signalling events. However, water flow through plants is itself regulated by Ca(2+), both in the apoplast via effects on cell wall structure and stomatal aperture, and within the symplast via Ca(2+)-mediated gating of aquaporins which regulates flow across membranes. In this review, an integrated model of water and Ca(2+) movement through plants is developed and how this affects [Ca] distribution and water flow within tissues is discussed, with particular emphasis on the role of aquaporins.

A single nucleotide substitution in TaHKT1;5-D controls shoot Na⁺ accumulation in bread wheat

Publisher: Cold Spring Harbor Laboratory

Date: 24-01-2020

DOI: 10.1101/2020.01.21.909887

Abstract: Improving salinity tolerance in the most widely cultivated cereal, bread wheat ( Triticum aestivum L.), is essential to increase grain yields on saline agricultural lands. A Portuguese landrace, Mocho de Espiga Branca accumulates up to 6 folds greater leaf and sheath sodium (Na + ) than two Australian cultivars, Gladius and Scout, under salt stress. Despite high leaf and sheath Na + concentrations, Mocho de Espiga Branca maintained similar salinity tolerance compared to Gladius and Scout. A naturally occurring single nucleotide substitution was identified in the gene encoding a major Na + transporter TaHKT1 -D in Mocho de Espiga Branca, which resulted in a L190P amino acid residue variation. This variant prevents Mocho de Espiga Branca from retrieving Na + from the root xylem leading to a high shoot Na + concentration. The identification of the tissue tolerant Mocho de Espiga Branca will accelerate the development of more elite salt tolerant bread wheat cultivars.

Roles of membrane transporters: connecting the dots from sequence to phenotype

Publisher: Oxford University Press (OUP)

Date: 06-2019

DOI: 10.1093/AOB/MCZ066

Abstract: Plant membrane transporters are involved in erse cellular processes underpinning plant physiology, such as nutrient acquisition, hormone movement, resource allocation, exclusion or sequestration of various solutes from cells and tissues, and environmental and developmental signalling. A comprehensive characterization of transporter function is therefore key to understanding and improving plant performance. In this review, we focus on the complexities involved in characterizing transporter function and the impact that this has on current genomic annotations. Specific ex les are provided that demonstrate why sequence homology alone cannot be relied upon to annotate and classify transporter function, and to show how even single amino acid residue variations can influence transporter activity and specificity. Misleading nomenclature of transporters is often a source of confusion in transporter characterization, especially for people new to or outside the field. Here, to aid researchers dealing with interpretation of large data sets that include transporter proteins, we provide ex les of transporters that have been assigned names that misrepresent their cellular functions. Finally, we discuss the challenges in connecting transporter function at the molecular level with physiological data, and propose a solution through the creation of new databases. Further fundamental in-depth research on specific transport (and other) proteins is still required without it, significant deficiencies in large-scale data sets and systems biology approaches will persist. Reliable characterization of transporter function requires integration of data at multiple levels, from amino acid residue sequence annotation to more in-depth biochemical, structural and physiological studies.

Chloride: not simply a ‘cheap osmoticum’, but a beneficial plant macronutrient

Publisher: Oxford University Press (OUP)

Date: 30-03-2017

DOI: 10.1093/JXB/ERX050

Abstract: At macronutrient levels, chloride has positive effects on plant growth, which are distinct from its function in photosynthesis..

Shoot chloride exclusion and salt tolerance in grapevine is associated with differential ion transporter expression in roots

Publisher: Springer Science and Business Media LLC

Date: 25-10-2014

DOI: 10.1186/S12870-014-0273-8

StomaAI: an efficient and user‐friendly tool for measurement of stomatal pores and density using deep computer vision

Publisher: Wiley

Date: 18-02-2023

DOI: 10.1111/NPH.18765

Abstract: Using microscopy to investigate stomatal behaviour is common in plant physiology research. Manual inspection and measurement of stomatal pore features is low throughput, relies upon expert knowledge to record stomatal features accurately, requires significant researcher time and investment, and can represent a significant bottleneck to research pipelines. To alleviate this, we introduce StomaAI (SAI): a reliable, user‐friendly and adaptable tool for stomatal pore and density measurements via the application of deep computer vision, which has been initially calibrated and deployed for the model plant Arabidopsis (dicot) and the crop plant barley (monocot grass). SAI is capable of producing measurements consistent with human experts and successfully reproduced conclusions of published datasets. SAI boosts the number of images that can be evaluated in a fraction of the time, so can obtain a more accurate representation of stomatal traits than is routine through manual measurement. An online demonstration of SAI is hosted at sai.aiml.team , and the full local application is publicly available for free on GitHub through dynames/sai‐app .

GmSALT3 expression improves reactive oxygen species detoxification in salt-stressed soybean roots

Publisher: Cold Spring Harbor Laboratory

Date: 26-05-2021

DOI: 10.1101/2021.05.26.445725

Abstract: Soybean plants are salinity (NaCl) sensitive, with their yield significantly decreased under moderately saline conditions. GmSALT3 is the dominant gene underlying a major QTL for salt tolerance in soybean. GmSALT3 encodes a transmembrane protein belonging to the plant cation roton exchanger (CHX) family. It is currently unknown through which molecular mechanism(s) the ER-localised GmSALT3 contributes to salinity tolerance, as its localisation excludes direct involvement in ion exclusion. In order to gain insights into potential molecular mechanism(s), we used RNA-seq analysis of roots from two soybean NILs (Near Isogenic Lines) NIL-S (salt-sensitive, Gmsalt3 ) and NIL-T (salt-tolerant, GmSALT3 ), grown under control and saline conditions (200 mM NaCl) at three time points (0h, 6h, and 3 days). Gene ontology (GO) analysis showed that NIL-T has greater responses aligned to oxidation reduction. ROS were shown less abundant and scavenging enzyme activity was higher in NIL-T, consistent with the RNA-seq data. Further analysis indicated that genes related to calcium signalling, vesicle trafficking and Casparian strip (CS) development were upregulated in NIL-T following salt treatment. We propose that GmSALT3 improves the ability of NIL-T to cope with saline stress through preventing ROS overaccumulation in roots, and potentially modulating Ca 2+ signalling, vesicle trafficking and formation of diffusion barriers. RNA-seq analysis revealed that GmSALT3, which confers improved salt tolerance on soybean, improves reactive oxygen species detoxification in roots.

Shoot Na+ Exclusion and Increased Salinity Tolerance Engineered by Cell Type–Specific Alteration of Na+ Transport in Arabidopsis    

Publisher: Oxford University Press (OUP)

Date: 07-2009

DOI: 10.1105/TPC.108.064568

Abstract: Soil salinity affects large areas of cultivated land, causing significant reductions in crop yield globally. The Na+ toxicity of many crop plants is correlated with overaccumulation of Na+ in the shoot. We have previously suggested that the engineering of Na+ exclusion from the shoot could be achieved through an alteration of plasma membrane Na+ transport processes in the root, if these alterations were cell type specific. Here, it is shown that expression of the Na+ transporter HKT1 in the mature root stele of Arabidopsis thaliana decreases Na+ accumulation in the shoot by 37 to 64%. The expression of HKT1 specifically in the mature root stele is achieved using an enhancer trap expression system for specific and strong overexpression. The effect in the shoot is caused by the increased influx, mediated by HKT1 , of Na+ into stelar root cells, which is demonstrated in planta and leads to a reduction of root-to-shoot transfer of Na+. Plants with reduced shoot Na+ also have increased salinity tolerance. By contrast, plants constitutively expressing HKT1 driven by the cauliflower mosaic virus 35S promoter accumulated high shoot Na+ and grew poorly. Our results demonstrate that the modification of a specific Na+ transport process in specific cell types can reduce shoot Na+ accumulation, an important component of salinity tolerance of many higher plants.

Non‐selective cation channel activity of aquaporin AtPIP2;1 regulated by Ca²⁺ and pH

Publisher: Wiley

Date: 18-10-2016

DOI: 10.1111/PCE.12832

Abstract: The aquaporin AtPIP2 is an abundant plasma membrane intrinsic protein in Arabidopsis thaliana that is implicated in stomatal closure, and is highly expressed in plasma membranes of root epidermal cells. When expressed in Xenopus laevis oocytes, AtPIP2 increased water permeability and induced a non-selective cation conductance mainly associated with Na

Split personality of Aluminum Activated Malate Transporter family proteins: facilitation of both GABA and malate transport

Publisher: Cold Spring Harbor Laboratory

Date: 07-11-2017

DOI: 10.1101/215335

Abstract: Plant aluminum activated malate transporters (ALMTs) are currently classified as anion channels they are also known to be regulated by erse signals leading to a range of physiological responses. Gamma-aminobutyric acid (GABA) regulation of anion flux through ALMT proteins requires the presence of a specific amino acid motif in ALMTs that shares similarity with a GABA-binding site in mammalian GABA A receptors. Here, we explore why TaALMT1-activation leads to a negative correlation between malate efflux and endogenous GABA concentrations ([GABA] i ) in both wheat root tips and in heterologous expression systems. We show that TaALMT1 activation reduces [GABA] i because TaALMT1 facilitates GABA efflux. TaALMT1-expression also leads to GABA transport into cells, demonstrated by a yeast complementation assay and via 14C GABA uptake into TaALMT1-expressing Xenopus laevis oocytes this was found to be a general feature of all ALMTs we examined. Mutation of the GABA motif (TaALMT1 F213C ) prevented both GABA influx and efflux, and uncoupled the relationship between malate efflux and [GABA] i . We conclude that ALMTs are likely to act as both GABA and anion transporters in planta . GABA and malate appear to interact with ALMTs in a complex manner regulating each other’s transport, suggestive of a role for ALMTs in communicating metabolic status.

SAI: Fast and automated quantification of stomatal parameters on microscope images

Publisher: Cold Spring Harbor Laboratory

Date: 10-02-2022

DOI: 10.1101/2022.02.07.479482

Abstract: Using microscopy to investigate stomatal behaviour is a common technique in plant physiology research. Manual inspection and measurement of stomatal features is a low throughput process in terms of time and human effort, which relies on expert knowledge to identify and measure stomata accurately. This process represents a significant bottleneck in research pipelines, adding significant researcher time to any project that requires it. To alleviate this, we introduce StomaAI (SAI): a reliable and user-friendly tool that measures stomata of the model plant Arabidopsis (dicot) and the crop plant barley (monocot grass) via the application of deep computer vision. We evaluated the reliability of predicted measurements: SAI is capable of producing measurements consistent with human experts and successfully reproduced conclusions of published datasets. Hence, SAI boosts the number of images that biologists can evaluate in a fraction of the time so is capable of obtaining more accurate and representative results.

gamma-Aminobutyric acid (GABA) signalling in plants

Publisher: Springer Science and Business Media LLC

Date: 12-11-2017

DOI: 10.1007/S00018-016-2415-7

Abstract: The role of γ-aminobutyric acid (GABA) as a signal in animals has been documented for over 60 years. In contrast, evidence that GABA is a signal in plants has only emerged in the last 15 years, and it was not until last year that a mechanism by which this could occur was identified-a plant 'GABA receptor' that inhibits anion passage through the aluminium-activated malate transporter family of proteins (ALMTs). ALMTs are multigenic, expressed in different organs and present on different membranes. We propose GABA regulation of ALMT activity could function as a signal that modulates plant growth, development, and stress response. In this review, we compare and contrast the plant 'GABA receptor' with mammalian GABA

Low-cost cross-taxon enrichment of mitochondrial DNA using in-house synthesised RNA probes

Publisher: Public Library of Science (PLoS)

Date: 04-02-2019

DOI: 10.1371/JOURNAL.PONE.0209499

Measurement of longitudinal flow decorrelations in Pb+Pb collisions at $$\sqrt{s_{\text {NN}}}=2.76$$

Publisher: Springer Science and Business Media LLC

Date: 02-2018

DOI: 10.1140/EPJC/S10052-018-5605-7

Exploiting natural variation to uncover candidate genes that control element accumulation in Arabidopsis thaliana

Publisher: Wiley

Date: 29-11-2012

DOI: 10.1111/J.1469-8137.2011.03977.X

Abstract: The plant ionome varies both inter‐ and intraspecifically despite the highly conserved roles for particular elements across the plant kingdom. Element storage requires transport across the plasma membrane and commonly deposition within the central vacuole. Therefore, tonoplast transport characteristics can be highly influential in controlling the plant ionome. As a result, in idual cell types of the same plant, each with unique transcriptomes and vacuolar proteomes, can display very different elemental profiles. Here we address the use of natural variation in Arabidopsis thaliana for identifying genes involved in elemental accumulation. We present a conceptual framework, exploiting publicly available leaf ionomic and transcriptomic data across 31 Arabidopsis accessions, that promises to accelerate conventional forward genetics approaches for candidate gene discovery. Utilizing this framework, we identify numerous genes with documented roles in accumulation of calcium, magnesium and zinc and implicate additional candidate genes. Where appropriate, we discuss their role in cell‐specific elemental accumulation. Currently, this framework could represent an alternate approach for identifying genes suitable for element biofortification of plants. Integration of additional cell‐specific and whole‐plant ‘omics’ datasets across Arabidopsis accessions under erse environmental conditions should enable this concept to be developed into a scalable and robust tool for linking genotype and phenotype.

Plants fighting back: to transport or not to transport, this is a structural question

Publisher: Elsevier BV

Date: 12-2018

DOI: 10.1016/J.PBI.2018.07.006

Abstract: Membrane-embedded transport proteins are fundamental to life their co-ordinated action controls the movement and distribution of solutes into, around and out of cells for signalling, metabolism, nutrition, stress tolerance and development. Here we outline two case studies of transport systems that plants use to tolerate soil elemental toxicity, demonstrating how iterative studies of protein structure and function result in unparalleled insights into transport mechanics. Further, we propose that integrative platforms of biological, biochemical and biophysical tools can provide quantitative data on substrate specificity and transport rates, which are important in understanding transporter evolution and their roles in cell biology and whole plant physiology. Such knowledge equips biotechnologists and breeders with the power to deliver improvements in crop yields in sub-optimal soils.

Journal of Experimental Botany: Preface

Publisher: Oxford University Press (OUP)

Date: 04-2011

DOI: 10.1093/JXB/ERR085

Correction: Corrigendum: GABA signalling modulates plant growth by directly regulating the activity of plant-specific anion transporters

Publisher: Springer Science and Business Media LLC

Date: 28-08-2015

DOI: 10.1038/NCOMMS9293

Abstract: Nature Communications 6, Article number: 7879 (2015) Published: 29 July 2015 Updated: 28 August 2015. The original version of this Article contained a typographical error in the spelling of the author Matthew Gilliham, which was incorrectly given as Matthew Gillham. This has now been corrected in both the PDF and HTML versions of the Article.

Grapevine salt tolerance

Publisher: Hindawi Limited

Date: 25-03-2021

DOI: 10.1111/AJGW.12487

Identification of a Stelar-Localized Transport Protein That Facilitates Root-to-Shoot Transfer of Chloride in Arabidopsis

Publisher: Oxford University Press (OUP)

Date: 11-12-2015

DOI: 10.1104/PP.15.01163

Molecular identification and functional analysis of a maize (Zea mays) DUR3 homolog that transports urea with high affinity

Publisher: Springer Science and Business Media LLC

Date: 19-12-2015

DOI: 10.1007/S00425-014-2219-7

Abstract: Successful molecular cloning and functional characterization of a high-affinity urea permease ZmDUR3 provide convincing evidence of ZmDUR3 roles in root urea acquisition and internal urea-N-remobilization of maize plants. Urea occurs ubiquitously in both soils and plants. Being a major form of nitrogen fertilizer, large applications of urea assist cereals in approaching their genetic yield potential, but due to the low nitrogen-use efficiency of crops, this practice poses a severe threat to the environment through their hypertrophication. To date, except for paddy rice, little is known about the biological basis for urea movement in dryland crops. Here, we report the molecular and physiological characterization of a maize urea transporter, ZmDUR3. We show using gene prediction, PCR-based cloning and yeast complementation, that a functional full-length cDNA encoding a 731 amino acids-containing protein with putative 15 transmembrane α-helixes for ZmDUR3 was successfully cloned. Root-influx studies using (15)N-urea demonstrated ZmDUR3 catalyzes urea transport with a K m at ~9 µM when expressed in the Arabidopsis dur3-mutant. qPCR analysis revealed that ZmDUR3 mRNA in roots was significantly upregulated by nitrogen depletion and repressed by reprovision of nitrogen after nitrogen starvation, indicating that ZmDUR3 is a nitrogen-responsive gene and relevant to plant nitrogen nutrition. Moreover, detection of higher urea levels in senescent leaves and obvious occurrence of ZmDUR3 transcripts in phloem-cells of mature/aged leaves strongly implies a role for ZmDUR3 in urea vascular loading. Significantly, expression of ZmDUR3 complemented atdur3-mutant of Arabidopsis, improving plant growth on low urea and increasing urea acquisition. As it also targets to the plasma membrane, our data suggest that ZmDUR3 functions as an active urea permease playing physiological roles in effective urea uptake and nitrogen remobilization in maize.

Energy costs of salt tolerance in crop plants

Publisher: Wiley

Date: 11-07-2019

DOI: 10.1111/NPH.15864

Abstract: Agriculture is expanding into regions that are affected by salinity. This review considers the energetic costs of salinity tolerance in crop plants and provides a framework for a quantitative assessment of costs. Different sources of energy, and modifications of root system architecture that would maximize water vs ion uptake are addressed. Energy requirements for transport of salt (NaCl) to leaf vacuoles for osmotic adjustment could be small if there are no substantial leaks back across plasma membrane and tonoplast in root and leaf. The coupling ratio of the H

Corrigendum

Publisher: Wiley

Date: 26-05-2022

DOI: 10.1111/NPH.18214

Molecular and electrophysiological characterization of anion transport in Arabidopsis thaliana pollen reveals regulatory roles for pH, Ca

Publisher: Wiley

Date: 27-05-2019

DOI: 10.1111/NPH.15863

Abstract: We investigated the molecular basis and physiological implications of anion transport during pollen tube (PT) growth in Arabidopsis thaliana (Col-0). Patch-cl whole-cell configuration analysis of pollen grain protoplasts revealed three subpopulations of anionic currents differentially regulated by cytoplasmic calcium ([Ca

Plant High-Affinity Potassium (HKT) Transporters Involved in Salinity Tolerance: Structural Insights to Probe Differences in Ion Selectivity

Publisher: MDPI AG

Date: 09-04-2013

DOI: 10.3390/IJMS14047660

Structural variations in wheat HKT1;5 underpin differences in Na+ transport capacity

Publisher: Springer Science and Business Media LLC

Date: 27-11-2017

DOI: 10.1007/S00018-017-2716-5

Abstract: An important trait associated with the salt tolerance of wheat is the exclusion of sodium ions (Na

Author response: A chloroplast retrograde signal, 3’-phosphoadenosine 5’-phosphate, acts as a secondary messenger in abscisic acid signaling in stomatal closure and germination

Publisher: eLife Sciences Publications, Ltd

Date: 11-03-2017

DOI: 10.7554/ELIFE.23361.026

Calcium storage in plants and the implications for calcium biofortification

Publisher: Springer Science and Business Media LLC

Date: 24-07-2010

DOI: 10.1007/S00709-010-0182-0

Abstract: Calcium (Ca) is an essential nutrient for plants and animals, with key structural and signalling roles, and its deficiency in plants can result in poor biotic and abiotic stress tolerance, reduced crop quality and yield. Likewise, low Ca intake in humans has been linked to various diseases (e.g. rickets, osteoporosis, hypertension and colorectal cancer) which can threaten quality of life and have major economic costs. Biofortification of various food crops with Ca has been suggested as a good method to enhance human intake of Ca and is advocated as an economically and environmentally advantageous strategy. Efforts to enhance Ca content of crops via transgenic means have had promising results. Overall Ca content of transgenic plants has been increased but in some cases adverse affects on plant function have been observed. This suggests that a better understanding of how Ca ions (Ca(2+)) are stored and transported through plants is required to maximise the effectiveness of future approaches.

VitiCanopy: A Free Computer App to Estimate Canopy Vigor and Porosity for Grapevine

Publisher: MDPI AG

Date: 23-04-2016

DOI: 10.3390/S16040585

Membrane Structure and the Study of Solute Transport Across Plant Membranes

Publisher: Wiley

Date: 15-03-2007

DOI: 10.1002/9780470988862.CH4

Cell-specific compartmentation of mineral nutrients is an essential mechanism for optimal plant productivity-another role for TPC1?

Publisher: Informa UK Limited

Date: 11-2011

DOI: 10.4161/PSB.6.11.17797

Simultaneous flux and current measurement from single plant protoplasts reveals a strong link between K⁺ fluxes and current, but no link between Ca²⁺ fluxes and current

Publisher: Wiley

Date: 08-03-2006

DOI: 10.1111/J.1365-313X.2006.02676.X

Salinity tolerance in soybean is modulated by natural variation in GmSALT3

Publisher: Wiley

Date: 04-11-2014

DOI: 10.1111/TPJ.12695

Abstract: The identification of genes that improve the salt tolerance of crops is essential for the effective utilization of saline soils for agriculture. Here, we use fine mapping in a soybean (Glycine max (L.) Merr.) population derived from the commercial cultivars Tiefeng 8 and 85-140 to identify GmSALT3 (salt tolerance-associated gene on chromosome 3), a dominant gene associated with limiting the accumulation of sodium ions (Na+) in shoots and a substantial enhancement in salt tolerance in soybean. GmSALT3 encodes a protein from the cation/H+ exchanger family that we localized to the endoplasmic reticulum and which is preferentially expressed in the salt-tolerant parent Tiefeng 8 within root cells associated with phloem and xylem. We identified in the salt-sensitive parent, 85-140, a 3.78-kb copia retrotransposon insertion in exon 3 of Gmsalt3 that truncates the transcript. By sequencing 31 soybean landraces and 22 wild soybean (Glycine soja) a total of nine haplotypes including two salt-tolerant haplotypes and seven salt-sensitive haplotypes were identified. By analysing the distribution of haplotypes among 172 Chinese soybean landraces and 57 wild soybean we found that haplotype 1 (H1, found in Tiefeng 8) was strongly associated with salt tolerance and is likely to be the ancestral allele. Alleles H2-H6, H8 and H9, which do not confer salinity tolerance, were acquired more recently. H1, unlike other alleles, has a wide geographical range including saline areas, which indicates it is maintained when required but its potent stress tolerance can be lost during natural selection and domestication. GmSALT3 is a gene associated with salt tolerance with great potential for soybean improvement.

Ethylene negatively regulates aluminium-induced malate efflux from wheat roots and tobacco cells transformed with TaALMT1

Publisher: Oxford University Press (OUP)

Date: 25-03-2014

DOI: 10.1093/JXB/ERU123

Protocol: optimising hydroponic growth systems for nutritional and physiological analysis of Arabidopsis thaliana and other plants

Publisher: Springer Science and Business Media LLC

Date: 05-02-2013

DOI: 10.1186/1746-4811-9-4

Abstract: Hydroponic growth systems are a convenient platform for studying whole plant physiology. However, we found through trialling systems as they are described in the literature that our experiments were frequently confounded by factors that affected plant growth, including algal contamination and hypoxia. We also found the way in which the plants were grown made them poorly amenable to a number of common physiological assays. The drivers for the development of this hydroponic system were: 1) the exclusion of light from the growth solution 2) to simplify the handling of in idual plants, and 3) the growth of the plant to allow easy implementation of multiple assays. These aims were all met by the use of pierced lids of black microcentrifuge tubes. Seed was germinated on a lid filled with an agar-containing germination media immersed in the same solution. Following germination, the liquid growth media was exchanged with the experimental solution, and after 14-21 days seedlings were transferred to larger tanks with aerated solution where they remained until experimentation. We provide details of the protocol including composition of the basal growth solution, and separate solutions with altered calcium, magnesium, potassium or sodium supply whilst maintaining the activity of the majority of other ions. We demonstrate the adaptability of this system for: gas exchange measurement on single leaves and whole plants qRT-PCR to probe the transcriptional response of roots or shoots to altered nutrient composition in the growth solution (we demonstrate this using high and low calcium supply) producing highly competent mesophyll protoplasts and, accelerating the screening of Arabidopsis transformants. This system is also ideal for manipulating plants for micropipette techniques such as electrophysiology or SiCSA. We present an optimised plant hydroponic culture system that can be quickly and cheaply constructed, and produces plants with similar growth kinetics to soil-grown plants, but with the advantage of being a versatile platform for a myriad of physiological and molecular biological measurements on all plant tissues at all developmental stages. We present ‘tips and tricks’ for the easy adoption of this hydroponic culture system.

Differential fruitset between grapevine cultivars is related to differences in pollen viability and amine concentration in flowers

Publisher: Hindawi Limited

Date: 12-11-2016

DOI: 10.1111/AJGW.12191

The role of plasma membrane intrinsic protein aquaporins in water transport through roots: Diurnal and drought stress responses reveal different strategies between isohydric and anisohydric cultivars of grapevine

Publisher: Oxford University Press (OUP)

Date: 05-11-2009

DOI: 10.1104/PP.108.128645

Abstract: We report physiological and anatomical characteristics of water transport across roots grown in soil of two cultivars of grapevine (Vitis vinifera) differing in response to water stress (Grenache, isohydric Chardonnay, anisohydric). Both cultivars have similar root hydraulic conductances (L o normalized to root dry weight) that change diurnally. There is a positive correlation between L o and transpiration. Under water stress, both cultivars have reduced minimum daily L o (predawn) attributed to the development of apoplastic barriers. Water-stressed and well-watered Chardonnay had the same diurnal change in litude of L o, while water-stressed Grenache showed a reduction in daily litude compared with well-watered plants. Hydraulic conductivity of root cortex cells (L pcell) doubles in Chardonnay but remains unchanged in Grenache. Of the two most highly expressed plasma membrane intrinsic protein (PIP) aquaporins in roots (VvPIP1 and VvPIP2 ), only VvPIP2 functions as a water channel in Xenopus laevis oocytes. VvPIP1 interacts with VvPIP2 to induce 3-fold higher water permeability. These two aquaporins are colocated in the root from in situ hybridization and immunolocalization of VvPIP1 and VvPIP2 subfamily members. They occur in root tip, exodermis, root cortex (detected up to 30 mm), and stele. VvPIP2 mRNA does not change diurnally or with water stress, in contrast to VvPIP1 , in which expression reflects the differences in L o and L pcell between cultivars in their responses to water stress and rewatering. VvPIP1 may regulate water transport across roots such that transpirational demand is matched by root water transport capacity. This occurs on a diurnal basis and in response to water stress that corresponds to the difference in drought tolerance between the cultivars.

Soybean CHX‐type ion transport protein GmSALT3 confers leaf Na⁺ exclusion via a root derived mechanism, and Cl⁻ exclusion via a shoot derived process

Publisher: Wiley

Date: 08-12-2020

DOI: 10.1111/PCE.13947

GABA signalling modulates stomatal opening to enhance plant water use efficiency and drought resilience

Publisher: Springer Science and Business Media LLC

Date: 29-03-2021

DOI: 10.1038/S41467-021-21694-3

Abstract: The non-protein amino acid γ-aminobutyric acid (GABA) has been proposed to be an ancient messenger for cellular communication conserved across biological kingdoms. GABA has well-defined signalling roles in animals however, whilst GABA accumulates in plants under stress it has not been determined if, how, where and when GABA acts as an endogenous plant signalling molecule. Here, we establish endogenous GABA as a bona fide plant signal, acting via a mechanism not found in animals. Using Arabidopsis thaliana , we show guard cell GABA production is necessary and sufficient to reduce stomatal opening and transpirational water loss, which improves water use efficiency and drought tolerance, via negative regulation of a stomatal guard cell tonoplast-localised anion transporter. We find GABA modulation of stomata occurs in multiple plants, including dicot and monocot crops. This study highlights a role for GABA metabolism in fine tuning physiology and opens alternative avenues for improving plant stress resilience.

Tissue tolerance: an essential but elusive trait for salt-tolerant crops

Publisher: CSIRO Publishing

Date: 2016

DOI: 10.1071/FP16187

Abstract: For a plant to persist in saline soil, osmotic adjustment of all plant cells is essential. The more salt-tolerant species accumulate Na+ and Cl– to concentrations in leaves and roots that are similar to the external solution, thus allowing energy-efficient osmotic adjustment. Adverse effects of Na+ and Cl– on metabolism must be avoided, resulting in a situation known as ‘tissue tolerance’. The strategy of sequestering Na+ and Cl– in vacuoles and keeping concentrations low in the cytoplasm is an important contributor to tissue tolerance. Although there are clear differences between species in the ability to accommodate these ions in their leaves, it remains unknown whether there is genetic variation in this ability within a species. This viewpoint considers the concept of tissue tolerance, and how to measure it. Four conclusions are drawn: (1) osmotic adjustment is inseparable from the trait of tissue tolerance (2) energy-efficient osmotic adjustment should involve ions and only minimal organic solutes (3) screening methods should focus on measuring tolerance, not injury and (4) high-throughput protocols that avoid the need for control plants and multiple Na+ or Cl– measurements should be developed. We present guidelines to identify useful genetic variation in tissue tolerance that can be harnessed for plant breeding of salt tolerance.

A search for resonances decaying into a Higgs boson and a new particle X in the XH→qqbb final state with the ATLAS detector

Publisher: Elsevier BV

Date: 04-2018

DOI: 10.1016/J.PHYSLETB.2018.01.042

Rapid shoot‐to‐root signalling regulates root hydraulic conductance via aquaporins

Publisher: Wiley

Date: 09-09-2013

DOI: 10.1111/PCE.12175

Abstract: We investigated how root hydraulic conductance (normalized to root dry weight, Lo ) is regulated by the shoot. Shoot topping (about 30% reduction in leaf area) reduced Lo of grapevine (Vitis vinifera L.), soybean (Glycine max L.) and maize (Zea mays L.) by 50 to 60%. More detailed investigations with soybean and grapevine showed that the reduction in Lo was not correlated with the reduction in leaf area, and shading or cutting single leaves had a similar effect. Percentage reduction in Lo was largest when initial Lo was high in soybean. Inhibition of Lo by weak acid (low pH) was smaller after shoot damage or leaf shading. The half time of reduction in Lo was approximately 5 min after total shoot decapitation. These characteristics indicate involvement of aquaporins. We excluded phloem-borne signals and auxin-mediated signals. Xylem-mediated hydraulic signals are possible since turgor rapidly decreased within root cortex cells after shoot topping. There was a significant reduction in the expression of several aquaporins in the plasma membrane intrinsic protein (PIP) family of both grapevine and soybean. In soybean, there was a five- to 10-fold reduction in GmPIP1 expression over 0.5-1 h which was sustained over the period of reduced Lo .

Translating knowledge about abiotic stress tolerance to breeding programmes

Publisher: Wiley

Date: 08-02-2017

DOI: 10.1111/TPJ.13456

Abstract: Plant breeding and improvements in agronomic practice are making a consistent contribution to increasing global crop production year upon year. However, the rate of yield improvement currently lags behind the targets set to produce enough food to meet the demands of the predicted global population in 2050. Furthermore, crops that are exposed to harmful abiotic environmental factors (abiotic stresses, e.g. water limitation, salinity, extreme temperature) are prone to reduced yields. Here, we briefly describe the processes undertaken in conventional breeding programmes, which are usually designed to improve yields in near-optimal conditions rather than specifically breeding for improved crop yield stability under stressed conditions. While there is extensive fundamental research activity that examines mechanisms of plant stress tolerance, there are few ex les that apply this research to improving commercial crop yields. There are notable exceptions, and we highlight some of these to demonstrate the magnitude of yield gains that could be made by translating agronomic, phenological and genetic solutions focused on improving or mitigating the effect of abiotic stress in the field in particular, we focus on improvements in crop water-use efficiency and salinity tolerance. We speculate upon the reasons for the disconnect between research and research translation. We conclude that to realise untapped rapid gains towards food security targets new funding structures need to be embraced. Such funding needs to serve both the core and collaborative activities of the fundamental, pre-breeding and breeding research communities in order to expedite the translation of innovative research into the fields of primary producers.

Author response: Plant Trans-Golgi Network/Early Endosome pH regulation requires Cation Chloride Cotransporter (CCC1)

Publisher: eLife Sciences Publications, Ltd

Date: 10-2021

DOI: 10.7554/ELIFE.70701.SA2

Hyperpolarisation‐activated calcium currents found only in cells from the elongation zone of Arabidopsis thaliana roots

Publisher: Wiley

Date: 2000

DOI: 10.1046/J.1365-313X.2000.00659.X

Abstract: Calcium currents across the plasma membrane of plant cells allow transduction of environmental signals as well as nutritive calcium uptake. Using transgenic Arabidopsis plants with cell-specific expression of green fluorescent protein (GFP), we analyzed whole cell calcium currents in epidermal cells of the rapidly growing root apex, mature epidermal cells, cortical and epidermal cells from the elongation zone, and mature pericycle cells. In cells only from the rapidly growing root apex, a hyperpolarization-activated calcium current was identified. This current was irreversibly inhibited by 10 microM Al3+, as well as being inhibited by 1 mM Co2+ and 100 microM verapamil. In no cells could a depolarisation-activated current be attributed to calcium influx. In the growing root apex, the hyperpolarization-activated calcium current may function to allow constitutive uptake of calcium for rapid cell ision and elongation.

MYB77 regulates high-affinity potassium uptake by promoting expression of HAK5.

Publisher: Wiley

Date: 26-07-2021

DOI: 10.1111/NPH.17589

Abstract: In Arabidopsis, the high-affinity K

The emerging role of GABA as a transport regulator and physiological signal

Publisher: Oxford University Press (OUP)

Date: 30-08-2021

DOI: 10.1093/PLPHYS/KIAB347

Abstract: While the proposal that γ-aminobutyric acid (GABA) acts a signal in plants is decades old, a signaling mode of action for plant GABA has been unveiled only relatively recently. Here, we review the recent research that demonstrates how GABA regulates anion transport through aluminum-activated malate transporters (ALMTs) and speculation that GABA also targets other proteins. The ALMT family of anion channels modulates multiple physiological processes in plants, with many members still to be characterized, opening up the possibility that GABA has broad regulatory roles in plants. We focus on the role of GABA in regulating pollen tube growth and stomatal pore aperture, and we speculate on its role in long-distance signaling and how it might be involved in cross talk with hormonal signals. We show that in barley (Hordeum vulgare), guard cell opening is regulated by GABA, as it is in Arabidopsis (Arabidopsis thaliana), to regulate water use efficiency, which impacts drought tolerance. We also discuss the links between glutamate and GABA in generating signals in plants, particularly related to pollen tube growth, wounding, and long-distance electrical signaling, and explore potential interactions of GABA signals with hormones, such as abscisic acid, jasmonic acid, and ethylene. We conclude by postulating that GABA encodes a signal that links plant primary metabolism to physiological status to fine tune plant responses to the environment.

A sterile hydroponic system for characterising root exudates from specific root types and whole-root systems of large crop plants

Publisher: Springer Science and Business Media LLC

Date: 12-2018

DOI: 10.1186/S13007-018-0380-X

gamma-Aminobutyric acid may directly or indirectly regulate Arabidopsis ALMT9

Publisher: Oxford University Press (OUP)

Date: 09-2022

DOI: 10.1093/PLPHYS/KIAC399

Abstract: The mechanism by which GABA regulates stomatal pore aperture and anion transport activity of ALUMINUM-ACTIVATED MALATE TRANSPORTER 9 is debated.

GmSALT3 confers shoot Na+ and Cl− exclusion in soybean via two distinct processes

Publisher: Cold Spring Harbor Laboratory

Date: 07-01-2020

DOI: 10.1101/2020.01.06.896456

Abstract: Soybean ( Glycine max ) yields are threatened by multiple stresses including soil salinity. GmSALT3 confers net shoot exclusion for both Na+ and Cl − and improves salt tolerance of soybean however, how the ER-localised GmSALT3 achieves this is unknown. Here, GmSALT3’s function was investigated in heterologous systems and near-isogenic lines that contained the full-length GmSALT3 (NIL-T salt-tolerant) or a truncated transcript Gmsalt3 (NIL-S salt-sensitive). GmSALT3 restored growth of K+-uptake-defective E. coli and contributed toward net influx and accumulation of Na+, K+, and Cl − in Xenopus laevis oocytes, while Gmsalt3 was non-functional. A time-course analysis of the NILs confirmed that shoot Cl − exclusion breaks down prior to Na+ exclusion, while grafting showed that shoot Na + exclusion occurs via a root xylem-based mechanism. In contrast, NIL-T plants exhibited significantly greater Cl − content in both the stem xylem and phloem sap compared to NIL-S, indicating that shoot Cl − exclusion likely depends upon novel phloem-based Cl − recirculation. NIL-T shoots grafted on NIL-S roots contained low shoot Cl − , which confirmed that Cl − recirculation is dependent on the presence of GmSALT3 in shoots. Overall, these findings provide new insights on GmSALT3’s impact on salinity tolerance and reveal a novel mechanism for shoot Cl– exclusion in plants. GmSALT3 improves soybean salt tolerance. Here, using heterologous expression, we found GmSALT3 is a functional ion transporter, and, in planta that it confers shoot salt exclusion through root-based Na + xylem exclusion and shoot-based Cl − exclusion via phloem derived Cl - recirculation.

Integrating membrane transport, signaling, and physiology

Publisher: Oxford University Press (OUP)

Date: 15-12-2021

DOI: 10.1093/PLPHYS/KIAB585

Salinity negatively affects pollen tube growth and fruit set in grapevines and is not mitigated by silicon

Publisher: American Society for Enology and Viticulture

Date: 05-01-2016

DOI: 10.5344/AJEV.2015.15004

Alluminating structure key to stress tolerance

Publisher: Springer Science and Business Media LLC

Date: 15-12-2021

DOI: 10.1038/S41422-021-00604-8

Measurement of the inclusive and fiducial $$t\bar{t}$$

Publisher: Springer Science and Business Media LLC

Date: 06-2018

DOI: 10.1140/EPJC/S10052-018-5904-Z

A calmodulin‐like protein regulates plasmodesmal closure during bacterial immune responses

Publisher: Wiley

Date: 17-05-2017

DOI: 10.1111/NPH.14599

Abstract: Plants sense microbial signatures via activation of pattern recognition receptors ( PPR s), which trigger a range of cellular defences. One response is the closure of plasmodesmata, which reduces symplastic connectivity and the capacity for direct molecular exchange between host cells. Plasmodesmal flux is regulated by a variety of environmental cues but the downstream signalling pathways are poorly defined, especially the way in which calcium regulates plasmodesmal closure. Here, we identify that closure of plasmodesmata in response to bacterial flagellin, but not fungal chitin, is mediated by a plasmodesmal‐localized Ca 2+ ‐binding protein Calmodulin‐like 41 ( CML 41). CML 41 is transcriptionally upregulated by flg22 and facilitates rapid callose deposition at plasmodesmata following flg22 treatment. CML 41 acts independently of other defence responses triggered by flg22 perception and reduces bacterial infection. We propose that CML 41 enables Ca 2+ ‐signalling specificity during bacterial pathogen attack and is required for a complete defence response against Pseudomonas syringae .

A Barley Efflux Transporter Operates in a Na⁺-Dependent Manner, as Revealed by a Multidisciplinary Platform

Publisher: Oxford University Press (OUP)

Date: 15-12-2015

DOI: 10.1105/TPC.15.00625

Enhanced reactive oxygen detoxification occurs in salt‐stressed soybean roots expressing GmSALT3

Publisher: Wiley

Date: 05-2022

DOI: 10.1111/PPL.13709

Abstract: Soybean ( Glycine max ) is an important crop globally for food and edible oil production. Soybean plants are sensitive to salinity (NaCl), with significant yield decreases reported under saline conditions. GmSALT3 is the dominant gene underlying a major QTL for salt tolerance in soybean. GmSALT3 encodes a transmembrane protein belonging to the plant cation roton exchanger (CHX) family, and is predominately expressed in root phloem and xylem associated cells under both saline and non‐saline conditions. It is currently unknown through which molecular mechanism(s) the ER‐localised GmSALT3 contributes to salinity tolerance, as its localisation excludes direct involvement in ion exclusion. In order to gain insights into potential molecular mechanism(s), we used RNA‐seq analysis of roots from two soybean NILs (near isogenic lines) NIL‐S (salt‐sensitive, Gmsalt3 ), and NIL‐T (salt‐tolerant, GmSALT3 ), grown under control and saline conditions (200 mM NaCl) at three time points (0 h, 6 h, and 3 days). Gene ontology (GO) analysis showed that NIL‐T has greater responses aligned to oxidation reduction. ROS were less abundant and scavenging enzyme activity was greater in NIL‐T, consistent with the RNA‐seq data. Further analysis indicated that genes related to calcium signalling, vesicle trafficking and Casparian strip (CS) development were upregulated in NIL‐T following salt treatment. We propose that GmSALT3 improves the ability of NIL‐T to cope with saline stress through preventing ROS overaccumulation in roots, and potentially modulating Ca 2+ signalling, vesicle trafficking and formation of diffusion barriers.

A search for pair-produced resonances in four-jet final states at $$\sqrt{s}=13$$ s = 13 $$\text {TeV}$$ TeV with the ATLAS detector

Publisher: Springer Science and Business Media LLC

Date: 03-2018

DOI: 10.1140/EPJC/S10052-018-5693-4

Identification of a unique ZIP transporter involved in zinc uptake via the arbuscular mycorrhizal fungal pathway

Publisher: Cold Spring Harbor Laboratory

Date: 29-09-2020

DOI: 10.1101/2020.09.28.317669

Abstract: Low soil zinc (Zn) availability is a limiting factor for crop yield, and increasing Zn content is a major target for the biofortification of major crops. Arbuscular mycorrhizal (AM) fungi associate with the roots of most terrestrial plant species and improve the host plant’s growth and nutrition through the mycorrhizal pathway of nutrient uptake. Although the physiology of Zn uptake through the mycorrhizal pathway is well established, the identity of the molecular components responsible for Zn transport in the mycorrhizal pathway are unknown. RNA-seq analysis identified the putative Zn transporter gene MtZIP14 by its marked up-regulation in Medicago truncatula roots when colonised by the AM fungus Rhizophagus irregularis under varying soil Zn supply. Expression of GFP-tagged MtZIP14 in roots revealed that it is exclusively localised to the site of plant-fungal nutrient exchange in cortical cells, the peri-arbuscular membrane. Expression of MtZIP14 in a yeast mutant lacking Zn transport function restored growth under low Zn availability. M. truncatula MtZIP14 loss-of-function mutants had reduced shoot biomass compared to the wild-type when colonised by AM fungi and grown under low Zn. Vesicular and arbuscular colonisation, but not hyphal colonisation, were also lower in mtzip14 mutant plants. Based on these results we propose that MtZIP14 plays a key role in the transport of Zn from AM fungus to plant across the peri-arbuscular membrane, and MtZIP14 function is crucial to plant competitiveness in a low Zn soil. Majority of crop plant species associate with arbuscular mycorrhizal fungi, which can increase plant nutrient uptake. Improving our knowledge of how Zn is taken up in mycorrhizal plants will lead to improved plant and human Zn nutrition outcomes. Here, we report a novel plant transporter with a major role in Zn nutrition of mycorrhizal plants. MtZIP14 is involved in Zn transport, is exclusively localised to the specialised plant-fungal interface in roots, and impairment of MtZIP14 gene function results in negative impacts on both plant growth and Zn nutrition.

Investigating glutamate receptor‐like gene co‐expression in Arabidopsis thaliana

Publisher: Wiley

Date: 05-03-2008

DOI: 10.1111/J.1365-3040.2008.01801.X

Abstract: There is increasing evidence of the important roles of glutamate receptors (GLRs) in plant development and in adaptation to stresses. However, the studies of these putative ion channels, both in planta and in Xenopus oocytes, may have been limited by our lack of knowledge of possible GLR heteromer formation in plants. We have developed a modification of the single-cell s ling technique to investigate GLR co-expression, and thus potential heteromer formation, in single cells of Arabidopsis thaliana leaves. Micro-EXpression lification (MEX) has allowed us to lify gene transcripts from a single cell, enabling expression of up to 100 gene transcripts to be assayed. We measured, on average, the transcripts of five to six different AtGLRs in a single cell. However, no consistent patterns of co-expression or cell-type-specific expression were detected, except that cells s led from the same plant showed similar expression profiles. The only discernible feature was the detection of AtGLR3.7 in every cell examined, an observation supported by GUS staining patterns in plants stably expressing promoter::uidA fusions. In addition, we found AtGLR3.7 expression in oocytes induces a Ba2+-, Ca2+- and Na+-permeable plasma membrane conductance.

A chloroplast retrograde signal, 3’phosphoadenosine 5’-phosphate, acts as a secondary messenger in abscisic acid signaling in stomatal closure and germination

Publisher: eLife Sciences Publications, Ltd

Date: 21-03-2017

DOI: 10.7554/ELIFE.23361

Abstract: Organelle-nuclear retrograde signaling regulates gene expression, but its roles in specialized cells and integration with hormonal signaling remain enigmatic. Here we show that the SAL1-PAP (3′-phosphoadenosine 5′- phosphate) retrograde pathway interacts with abscisic acid (ABA) signaling to regulate stomatal closure and seed germination in Arabidopsis. Genetically or exogenously manipulating PAP bypasses the canonical signaling components ABA Insensitive 1 (ABI1) and Open Stomata 1 (OST1) priming an alternative pathway that restores ABA-responsive gene expression, ROS bursts, ion channel function, stomatal closure and drought tolerance in ost1-2. PAP also inhibits wild type and abi1-1 seed germination by enhancing ABA sensitivity. PAP-XRN signaling interacts with ABA, ROS and Ca2+ up-regulating multiple ABA signaling components, including lowly-expressed Calcium Dependent Protein Kinases (CDPKs) capable of activating the anion channel SLAC1. Thus, PAP exhibits many secondary messenger attributes and exemplifies how retrograde signals can have broader roles in hormone signaling, allowing chloroplasts to fine-tune physiological responses.

Glutamate Receptor–Like Genes Form Ca ²⁺ Channels in Pollen Tubes and Are Regulated by Pistil d

Publisher: American Association for the Advancement of Science (AAAS)

Date: 22-04-2011

DOI: 10.1126/SCIENCE.1201101

Abstract: Amino acid modulation of Ca 2+ signaling guides growth of plant pollen tubes.

Modified method for producing grapevine plants in controlled environments

Publisher: American Society for Enology and Viticulture

Date: 11-04-2014

DOI: 10.5344/AJEV.2014.13121

AtNPF2.5 Modulates Chloride (Cl−) Efflux from Roots of Arabidopsis thaliana

Publisher: Frontiers Media SA

Date: 23-06-2017

DOI: 10.3389/FPLS.2016.02013

SpaceHort: redesigning plants to support space exploration and on-earth sustainability

Publisher: Elsevier BV

Date: 02-2022

DOI: 10.1016/J.COPBIO.2021.08.018

Abstract: Crewed missions to Mars are planned within the next twenty years. Production of food and materials in situ will eventually be necessary for mission success. This will require the development of crops which can thrive in environments we can sustain in Space. Here, we discuss the challenges we must solve to provide adequate nutrition to support long term Space habitation. Further, we propose that plants are an ideal biomanufacturing platform for producing pharmaceuticals and biomaterials on demand. Designing Space plants requires advances in our ability to engineer plant biology in a predictive manner. Parallel development of suitable tightly controlled growth environments, including extensive monitoring and sensing, will also be a key enabler. Collectively, such research promises to deliver solutions for progressing sustainable closed environment agriculture on Earth.

Analysis of the salt exclusion phenotype in rooted leaves of grapevine (Vitisspp.)

Publisher: Hindawi Limited

Date: 16-01-2018

DOI: 10.1111/AJGW.12334

Potential abiotic stress targets for modern genetic manipulation

Publisher: Oxford University Press (OUP)

Date: 15-11-2023

DOI: 10.1093/PLCELL/KOAC327

Abstract: Research into crop yield and resilience has underpinned global food security, evident in yields tripling in the past 5 decades. The challenges that global agriculture now faces are not just to feed 10+ billion people within a generation, but to do so under a harsher, more variable, and less predictable climate, and in many cases with less water, more expensive inputs, and declining soil quality. The challenges of climate change are not simply to breed for a “hotter drier climate,” but to enable resilience to floods and droughts and frosts and heat waves, possibly even within a single growing season. How well we prepare for the coming decades of climate variability will depend on our ability to modify current practices, innovate with novel breeding methods, and communicate and work with farming communities to ensure viability and profitability. Here we define how future climates will impact farming systems and growing seasons, thereby identifying the traits and practices needed and including exemplars being implemented and developed. Critically, this review will also consider societal perspectives and public engagement about emerging technologies for climate resilience, with participatory approaches presented as the best approach.

The “Gatekeeper” Concept: Cell‐Type Specific Molecular Mechanisms of Plant Adaptation to Abiotic Stress

Publisher: Wiley

Date: 24-04-2015

DOI: 10.1002/9781118860526.CH4

Plant Trans-Golgi Network/Early Endosome pH regulation requires Cation Chloride Cotransporter (CCC1)

Publisher: eLife Sciences Publications, Ltd

Date: 06-01-2022

DOI: 10.7554/ELIFE.70701

Abstract: Plant cells maintain a low luminal pH in the trans-Golgi-network/early endosome (TGN/EE), the organelle in which the secretory and endocytic pathways intersect. Impaired TGN/EE pH regulation translates into severe plant growth defects. The identity of the proton pump and proton/ion antiporters that regulate TGN/EE pH have been determined, but an essential component required to complete the TGN/EE membrane transport circuit remains unidentified − a pathway for cation and anion efflux. Here, we have used complementation, genetically encoded fluorescent sensors, and pharmacological treatments to demonstrate that Arabidopsis cation chloride cotransporter (CCC1) is this missing component necessary for regulating TGN/EE pH and function. Loss of CCC1 function leads to alterations in TGN/EE-mediated processes including endocytic trafficking, exocytosis, and response to abiotic stress, consistent with the multitude of phenotypic defects observed in ccc1 knockout plants. This discovery places CCC1 as a central component of plant cellular function.

Plant Cation-Chloride Cotransporters (CCC): Evolutionary Origins and Functional Insights

Publisher: MDPI AG

Date: 06-02-2018

DOI: 10.3390/IJMS19020492

Magnesium transporters, MGT2/MRS2-1 and MGT3/MRS2-5, are important for magnesium partitioning within Arabidopsis thaliana mesophyll vacuoles

Publisher: Wiley

Date: 24-01-2011

DOI: 10.1111/J.1469-8137.2010.03619.X

Abstract: See also the Commentary by Waters

Functional differences in transport properties of natural HKT1;1 variants influence shoot Na

Publisher: Wiley

Date: 21-11-2018

DOI: 10.1111/NPH.14888

Abstract: Under salinity, Vitis spp. rootstocks can mediate salt (NaCl) exclusion from grafted V. vinifera scions enabling higher grapevine yields and production of superior wines with lower salt content. Until now, the genetic and mechanistic elements controlling sodium (Na

Plant Trans-Golgi Network/Early Endosome pH regulation requires Cation Chloride Cotransporter (CCC1)

Publisher: Cold Spring Harbor Laboratory

Date: 02-01-2020

DOI: 10.1101/2020.01.02.893073

Abstract: Plant cells maintain a low luminal pH in the Trans-Golgi-Network/Early Endosome (TGN/EE), the organelle in which the secretory and endocytic pathways intersect. Impaired TGN/EE pH regulation translates into severe plant growth defects. The identity of the proton pump and proton/ion antiporters that regulate TGN/EE pH have been determined, but an essential component required to complete the TGN/EE membrane transport circuit remains unidentified − a pathway for cation and anion efflux. Here, we have used complementation, genetically encoded fluorescent sensors, and pharmacological treatments to demonstrate that the TGN/EE localised Arabidopsis Cation Chloride Cotransporter (CCC1) is this missing component necessary for regulating TGN/EE pH and function. Loss of CCC1 function leads to alterations in TGN/EE-mediated processes including endo- and exocytosis, and trafficking to the vacuole, and response to abiotic stress, consistent with the multitude of phenotypes observed in ccc1 knockout plants. This discovery places CCC1 as a central component of plant cellular function.

Lancaster University

Location: United Kingdom of Great Britain and Northern Ireland

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ARC Centre Of Excellence In Plant Energy Biology

Location: Australia

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University Of Cambridge

Location: United Kingdom of Great Britain and Northern Ireland

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University Of Adelaide

Location: Australia

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ARC Future Fellowships - Grant ID: FT130100709

Start Date: 07-2013

End Date: 12-2017

Amount: $735,032.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP210102828

Start Date: 12-2021

End Date: 11-2024

Amount: $509,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP130100648

Start Date: 2014

End Date: 06-2019

Amount: $588,029.00

Funder: Australian Research Council

ARC Centres Of Excellence - Grant ID: CE230100015

Start Date: 2023

End Date: 12-2029

Amount: $35,000,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP130104205

Start Date: 2013

End Date: 12-2014

Amount: $420,000.00

Funder: Australian Research Council

ARC Centres Of Excellence - Grant ID: CE140100008

Start Date: 2014

End Date: 05-2021

Amount: $26,000,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP170104384

Start Date: 2017

End Date: 12-2019

Amount: $375,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE210100155

Start Date: 2021

End Date: 06-2022

Amount: $909,079.00

Funder: Australian Research Council

Industrial Transformation Training Centres - Grant ID: IC170100008

Start Date: 02-2018

End Date: 12-2024

Amount: $4,459,672.00

Funder: Australian Research Council

Industrial Transformation Training Centres - Grant ID: IC210100047

Start Date: 09-2022

End Date: 08-2027

Amount: $5,000,000.00

Funder: Australian Research Council