ORCID Profile
0000-0002-4446-3432
Current Organisation
University of Queensland
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Crop and Pasture Production | Plant Protection (Pests, Diseases And Weeds) | Plant Improvement (Selection, Breeding And Genetic Engineering) | Plant Pathology | Biochemistry and Cell Biology | Botany Not Elsewhere Classified | Genetics | Plant Biochemistry And Physiology | Zoology | Plant Biology | Horticultural Production | Plant Protection (Pests, Diseases And Weeds) | Plant Cell and Molecular Biology | Genomics | Analytical Biochemistry | Gene Expression | Protein Targeting And Signal Transduction | Horticultural Crop Improvement (Selection and Breeding) | Crop and Pasture Improvement (Selection and Breeding) | Plant Physiology | Cell Development (Incl. Cell Division And Apoptosis) | Invertebrate Biology |
ANZSRC Socio-Economic Objective (SEO)
Field crops | Biological sciences | Forestry | Environmentally Sustainable Plant Production not elsewhere classified | Primary products from plants | Horticultural crops | Fresh fruit and vegetables (post harvest) | Sorghum | Wheat | Control of pests and exotic species | Tropical Fruit
Related Links
Publications
Nucleic acid purification from plants, animals and microbes in under 30 seconds
Publisher: Public Library of Science (PLoS)
Date: 21-11-2017
Biochemical characterization of arabidopsis developmentally regulated G-proteins (DRGs)
Publisher: Elsevier BV
Date: 10-2009
DOI: 10.1016/J.PEP.2009.05.009
Abstract: Developmentally regulated G-proteins (DRGs) are a highly conserved family of GTP-binding proteins found in archaea, plants, fungi and animals, indicating important roles in fundamental pathways. Their function is poorly understood, but they have been implicated in cell ision, proliferation, and growth, as well as several medical conditions. In idual subfamilies within the G-protein superfamily possess unique nucleotide binding and hydrolysis rates that are intrinsic to their cellular function, and so characterization of these rates for a particular G-protein may provide insight into its cellular activity. We have produced recombinant active DRG protein using a bacterial expression system and refolding, and performed biochemical characterization of their GTP binding and hydrolysis. We show that recombinant Arabidopsis thaliana atDRG1 and atDRG2a are able to bind GDP and GTP. We also show that DRGs can hydrolyze GTP in vitro without the assistance of GTPase-activating proteins and guanine exchange factors. The atDRG proteins hydrolyze GTP at a relatively slow rate (0.94x10(-3)min(-1) for DRG1 and 1.36x10(-3)min(-1) for DRG2) that is consistent with their nearest characterized relatives, the Obg subfamily. The ability of DRGs to bind nucleotide substrates without assistance, their slow rate of GTP hydrolysis, heat stress activation and domain conservation suggest a possible role as a chaperone in ribosome assembly in response to stress as it has been suggested for the Obg proteins, a different but related G-protein subfamily.
Calcium-dependent protein kinases in cotton: insights into early plant responses to salt stress
Publisher: Springer Science and Business Media LLC
Date: 17-01-2018
IDENTIFICATION AND CHARACTERIZATION OF 3 PUTATIVE GENES FOR 1-AMINOCYCLOPROPANE-1-CARBOXYLATE SYNTHASE FROM ETIOLATED MUNG BEAN HYPOCOTYL SEGMENTS
Publisher: Springer Science and Business Media LLC
Date: 02-1992
DOI: 10.1007/BF00020022
Transient and stable transformation in mango by particle bombardment
Publisher: International Society for Horticultural Science (ISHS)
Date: 02-2000
A multiplex CRISPR/Cas9 platform for fast and efficient editing of multiple genes in Arabidopsis
Publisher: Springer Science and Business Media LLC
Date: 10-12-2016
Heterotrimeric G Proteins Serve as a Converging Point in Plant Defense Signaling Activated by Multiple Receptor-Like Kinases
Publisher: Oxford University Press (OUP)
Date: 19-02-2013
Abstract: In fungi and metazoans, extracellular signals are often perceived by G-protein-coupled receptors (GPCRs) and transduced through heterotrimeric G-protein complexes to downstream targets. Plant heterotrimeric G proteins are also involved in erse biological processes, but little is known about their upstream receptors. Moreover, the presence of bona fide GPCRs in plants is yet to be established. In Arabidopsis (Arabidopsis thaliana), heterotrimeric G protein consists of one Gα subunit (G PROTEIN α-SUBUNIT1), one Gβ subunit (ARABIDOPSIS G PROTEIN β-SUBUNIT1 [AGB1]), and three Gγs subunits (ARABIDOPSIS G PROTEIN γ-SUBUNIT1 [AGG1], AGG2, and AGG3). We identified AGB1 from a suppressor screen of BAK1-interacting receptor-like kinase1-1 (bir1-1), a mutant that activates cell death and defense responses mediated by the receptor-like kinase (RLK) SUPPRESSOR OF BIR1-1. Mutations in AGB1 suppress the cell death and defense responses in bir1-1 and transgenic plants overexpressing SUPPRESSOR OF BIR1-1. In addition, agb1 mutant plants were severely compromised in immunity mediated by three other RLKs, FLAGELLIN-SENSITIVE2 (FLS2), Elongation Factor-TU RECEPTOR (EFR), and CHITIN ELICITOR RECEPTOR KINASE1 (CERK1), respectively. By contrast, G PROTEIN α-SUBUNIT1 is not required for either cell death in bir1-1 or pathogen-associated molecular pattern-triggered immunity mediated by FLS2, EFR, and CERK1. Further analysis of agg1 and agg2 mutant plants indicates that AGG1 and AGG2 are also required for pathogen-associated molecular pattern-triggered immune responses mediated by FLS2, EFR, and CERK1, as well as cell death and defense responses in bir1-1. We hypothesize that the Arabidopsis heterotrimeric G proteins function as a converging point of plant defense signaling by mediating responses initiated by multiple RLKs, which may fulfill equivalent roles to GPCRs in fungi and animals.
Heterotrimeric G-proteins facilitate resistance to plant pathogenic viruses in Arabidopsis thaliana (L.) Heynh
Publisher: Informa UK Limited
Date: 25-07-2016
Etr1-1 gene expression alters regeneration patterns in transgenic lettuce stimulating root formation
Publisher: Springer Science and Business Media LLC
Date: 07-2004
Nucleotide exchange–dependent and nucleotide exchange–independent functions of plant heterotrimeric GTP-binding proteins
Publisher: American Association for the Advancement of Science (AAAS)
Date: 05-11-2019
DOI: 10.1126/SCISIGNAL.AAV9526
Abstract: G protein α subunits in Arabidopsis can function independently of guanine nucleotide exchange.
Novel Chitinase Gene LOC_Os11g47510 from Indica Rice Tetep Provides Enhanced Resistance against Sheath Blight Pathogen Rhizoctonia solani in Rice
Publisher: Frontiers Media SA
Date: 25-04-2017
Advanced DNA-based point-of-care diagnostic methods for plant diseases detection
Publisher: Frontiers Media SA
Date: 06-12-2017
EST Sequencing of Meloidogyne javanica Infected Pineapple Root Tissues Reveals Changes in Gene Expression during Root-Knot Nematode Induced Gall Formation
Publisher: Springer Science and Business Media LLC
Date: 13-03-2014
Plant G-Proteins Come of Age: Breaking the Bond with Animal Models
Publisher: Frontiers Media SA
Date: 24-05-2016
Cosuppression of eukaryotic release factor 1-1 in Arabidopsis affects cell elongation and radial cell division
Publisher: Oxford University Press (OUP)
Date: 19-08-2005
Abstract: The role of the eukaryotic release factor 1 (eRF1) in translation termination has previously been established in yeast however, only limited characterization has been performed on any plant homologs. Here, we demonstrate that cosuppression of eRF1-1 in Arabidopsis (Arabidopsis thaliana) has a profound effect on plant morphology, resulting in what we term the broomhead phenotype. These plants primarily exhibit a reduction in internode elongation causing the formation of a broomhead-like cluster of malformed siliques at the top of the inflorescence stem. Histological analysis of broomhead stems revealed that cells are reduced in height and display ectopic lignification of the phloem cap cells, some phloem sieve cells, and regions of the fascicular cambium, as well as enhanced lignification of the interfascicular fibers. We also show that cell ision in the fascicular cambial regions is altered, with the majority of vascular bundles containing cambial cells that are disorganized and possess enlarged nuclei. This is the first attempt at functional characterization of a release factor in vivo in plants and demonstrates the importance of eRF1-1 function in Arabidopsis.
IDENTIFICATION OF 2 NEW MEMBERS OF THE 1-AMINOCYCLOPROPANE-1-CARBOXYLATE SYNTHASE-ENCODING MULTIGENE FAMILY IN MUNG BEAN
Publisher: Elsevier BV
Date: 1993
DOI: 10.1016/0378-1119(93)90132-M
Abstract: The key enzyme regulating ethylene biosynthesis in higher plants is 1-aminocyclopropane-1-carboxylate (ACC) synthase. In mung bean (MB), the existence of three genes encoding this enzyme has previously been reported [Botella et al., Plant Mol. Biol. 18 (1992) 793-797], one of which corresponds to a full-length indole-3-acetic acid-inducible cDNA [Botella et al., Plant Mol. Biol. (1992) 425-436]. In this paper we report the cloning of two new genomic sequences coding for ACC synthase in MB (MAC-4 and MAC-5). MAC-4 is 1340 bp long and encodes 388 amino acids (aa) while MAC-5 is 1393 bp long and encodes for 391 aa. Genomic Southern analysis suggests the existence of only one copy of each gene in the genome.
Heterotrimeric G Protein γ Subunits Provide Functional Selectivity in Gβγ Dimer Signaling in Arabidopsis
Publisher: Oxford University Press (OUP)
Date: 04-2007
An easy-to-perform, culture-free Campylobacter point-of-management assay for processing plant applications
Publisher: Oxford University Press (OUP)
Date: 03-2020
DOI: 10.1111/JAM.14509
Abstract: Current culture-based methods for detection and determination of C ylobacter levels on processed chickens takes at least 2 days. Here we sought to develop a new complete, low-cost and rapid (approximately 2·5 h) detection system requiring minimal operator input. We observed a strong correlation between culture-based cell counts and our ability to detect either C ylobacter jejuni or C ylobacter coli by loop-mediated isothermal lification from the same s les. This knowledge was used to develop a rapid and simple five-step assay to quantify C ylobacter, which was subsequently assessed for its specificity, reproducibility and accuracy in quantifying C ylobacter levels from processed chickens. The assay was found to be highly specific for C. jejuni and C. coli and was capable of distinguishing between s les that are either within or exceeding the industry set target of 6000 C ylobacter colony forming units (CFU) per carcass (equivalent to 12 CFU per ml of chicken rinse) with & % accuracy relative to culture-based methods. Our method can reliably quantify C ylobacter counts of processed chickens with an accuracy comparable to culture-based assays but provides results within hours as opposed to days. The research presented here will help improve food safety by providing fast C ylobacter detection that will enable the implementation of real-time risk management strategies in poultry processing plants to rapidly test processed chickens and identify effective intervention strategies. This technology is a powerful tool that can be easily adapted for other organisms and thus could be highly beneficial for a broad range of industries.
Rapid (30-second), equipment-free purification of nucleic acids using easy-to-make dipsticks
Publisher: Springer Science and Business Media LLC
Date: 10-2020
Biotechnology.
Publisher: CABI
Date: 2018
DOI: 10.1079/9781786393302.0085
Abstract: his chapter discusses tissue culture, including topics on micropropagation, organogenesis and somatic embryogenesis, in vitro production of metabolites, cultivar improvement, beneficial microorganisms, somaclonal variation, and in vitro germplasm conservation of pineapple. Anther and ovule culture protoplast isolation and fusion genes and genetic resources, genomes, genetic engineering and molecular markers are also described.
Endogenous U6 promoters improve CRISPR/Cas9 editing efficiencies in Sorghum bicolor and show potential for applications in other cereals
Publisher: Springer Science and Business Media LLC
Date: 02-12-2022
Evaluation and improvement of isothermal amplification methods for point-of-need plant disease diagnostics
Publisher: Public Library of Science (PLoS)
Date: 29-06-2020
Effect of light‐dark transition on glutamine synthetase activity in tomato leaves
Publisher: Wiley
Date: 04-1986
Membrane-Localized Extra-Large G Proteins and Gβγ of the Heterotrimeric G Proteins Form Functional Complexes Engaged in Plant Immunity in Arabidopsis
Publisher: Oxford University Press (OUP)
Date: 14-01-2015
Recent advances in the development of transgenic papaya technology
Publisher: Elsevier
Date: 2008
Re-purposing bridging flocculation for on-site, rapid, qualitative DNA detection in resource-poor settings
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C4CC10068A
Abstract: A novel DNA mediated bridging flocculation assay was developed for evaluating lified DNA in low resource settings.
Binary vectors for sense and antisense expression of arabidopsis ESTs
Publisher: Springer Science and Business Media LLC
Date: 1998
Present and future potential of pineapple biotechnology
Publisher: International Society for Horticultural Science (ISHS)
Date: 2005
Developing pineapple fruit has a small transcriptome dominated by metallothionein
Publisher: Oxford University Press (OUP)
Date: 11-2005
DOI: 10.1093/JXB/ERI015
Abstract: In a first step toward understanding the molecular basis of pineapple fruit development, a sequencing project was initiated to survey a range of expressed sequences from green unripe and yellow ripe fruit tissue. A highly abundant metallothionein transcript was identified during library construction, and was estimated to account for up to 50% of all EST library clones. Library clones with metallothionein subtracted were sequenced, and 408 unripe green and 1140 ripe yellow edited EST clone sequences were retrieved. Clone redundancy was high, with the combined 1548 clone sequences clustering into just 634 contigs comprising 191 consensus sequences and 443 singletons. Half of the EST clone sequences clustered within 13.5% and 9.3% of contigs from green unripe and yellow ripe libraries, respectively, indicating that a small subset of genes dominate the majority of the transcriptome. Furthermore, sequence cluster analysis, northern analysis, and functional classification revealed major differences between genes expressed in the unripe green and ripe yellow fruit tissues. Abundant genes identified from the green fruit include a fruit bromelain and a bromelain inhibitor. Abundant genes identified in the yellow fruit library include a MADS box gene, and several genes normally associated with protein synthesis, including homologues of ribosomal L10 and the translation factors SUI1 and eIF5A. Both the green unripe and yellow ripe libraries contained high proportions of clones associated with oxidative stress responses and the detoxification of free radicals.
Host-delivered RNAi: an effective strategy to silence genes in plant parasitic nematodes.
Publisher: Springer Science and Business Media LLC
Date: 25-07-2007
DOI: 10.1007/S00425-007-0588-X
Abstract: Root-knot nematodes (Meloidogyne spp.) are obligate, sedentary endoparasites that infect many plant species causing large economic losses worldwide. Available nematicides are being banned due to their toxicity or ozone-depleting properties and alternative control strategies are urgently required. We have produced transgenic tobacco (Nicotiana tabacum) plants expressing different dsRNA hairpin structures targeting a root-knot nematode (Meloidogyne javanica) putative transcription factor, MjTis11. We provide evidence that MjTis11 was consistently silenced in nematodes feeding on the roots of transgenic plants. The observed silencing was specific for MjTis11, with other sequence-unrelated genes being unaffected in the nematodes. Those transgenic plants able to induce silencing of MjTis11, also showed the presence of small interfering RNAs. Even though down-regulation of MjTis11 did not result in a lethal phenotype, this study demonstrates the feasibility of silencing root-knot nematode genes by expressing dsRNA in the host plant. Host-delivered RNA interference-triggered (HD-RNAi) silencing of parasite genes provides a novel disease resistance strategy with wide biotechnological applications. The potential of HD-RNAi is not restricted to parasitic nematodes but could be adapted to control other plant-feeding pests.
Pineapple translation factor SUI1 and ribosomal protein L36 promoters drive constitutive transgene expression patterns in Arabidopsis thaliana
Publisher: Springer Science and Business Media LLC
Date: 22-12-2012
DOI: 10.1007/S11103-012-0002-3
Abstract: The availability of a variety of promoter sequences is necessary for the genetic engineering of plants, in basic research studies and for the development of transgenic crops. In this study, the promoter and 5' untranslated regions of the evolutionally conserved protein translation factor SUI1 gene and ribosomal protein L36 gene were isolated from pineapple and sequenced. Each promoter was translationally fused to the GUS reporter gene and transformed into the heterologous plant system Arabidopsis thaliana. Both the pineapple SUI1 and L36 promoters drove GUS expression in all tissues of Arabidopsis at levels comparable to the CaMV35S promoter. Transient assays determined that the pineapple SUI1 promoter also drove GUS expression in a variety of climacteric and non-climacteric fruit species. Thus the pineapple SUI1 and L36 promoters demonstrate the potential for using translation factor and ribosomal protein genes as a source of promoter sequences that can drive constitutive transgene expression patterns.
Tobacco isoenzyme 1 of NAD(H)-dependent glutamate dehydrogenase catabolizes glutamate in vivo
Publisher: Oxford University Press (OUP)
Date: 17-11-2007
A detailed procedure for CRISPR/Cas9-mediated gene editing in Arabidopsis thaliana
Publisher: Elsevier BV
Date: 08-2015
Diversity of heterotrimeric G-protein γ subunits in plants
Publisher: Springer Science and Business Media LLC
Date: 31-10-2012
Abstract: Heterotrimeric G-proteins, consisting of three subunits Gα, Gβ and Gγ are present in most eukaryotes and mediate signaling in numerous biological processes. In plants, Gγ subunits were shown to provide functional selectivity to G-proteins. Three unconventional Gγ subunits were recently reported in Arabidopsis, rice and soybean but no structural analysis has been reported so far. Their relationship with conventional Gγ subunits and taxonomical distribution has not been yet demonstrated. After an extensive similarity search through plant genomes, transcriptomes and proteomes we assembled over 200 non-redundant proteins related to the known Gγ subunits. Structural analysis of these sequences revealed that most of them lack the obligatory C-terminal prenylation motif (CaaX). According to their C-terminal structures we classified the plant Gγ subunits into three distinct types. Type A consists of Gγ subunits with a putative prenylation motif. Type B subunits lack a prenylation motif and do not have any cysteine residues in the C-terminal region, while type C subunits contain an extended C-terminal domain highly enriched with cysteines. Comparative analysis of C-terminal domains of the proteins, intron-exon arrangement of the corresponding genes and phylogenetic studies suggested a common origin of all plant Gγ subunits. Phylogenetic analyses suggest that types C and B most probably originated independently from type A ancestors. We speculate on a potential mechanism used by those Gγ subunits lacking isoprenylation motifs to anchor the Gβγ dimer to the plasma membrane and propose a new flexible nomenclature for plant Gγ subunits. Finally, in the light of our new classification, we give a word of caution about the interpretation of Gγ research in Arabidopsis and its generalization to other plant species.
Towards the production of transgenic pineapple to control flowering and ripening
Publisher: International Society for Horticultural Science (ISHS)
Date: 05-2000
Molecular Inversion Probe: A New Tool for Highly Specific Detection of Plant Pathogens
Publisher: Public Library of Science (PLoS)
Date: 24-10-2014
Isolation of a novel G-protein γ-subunit from Arabidopsis thaliana and its interaction with Gβ
Publisher: Elsevier BV
Date: 30-08-2001
DOI: 10.1016/S0167-4781(01)00262-7
Abstract: There is increasing evidence that heterotrimeric G-proteins (G-proteins) are involved in many plant processes including phytohormone response, pathogen defence and stomatal control. In animal systems, each of the three G-protein subunits belong to large multigene families however, few subunits have been isolated from plants. Here we report the cloning of a second plant G-protein gamma-subunit (AGG2) from Arabidopsis thaliana. The predicted AGG2 protein sequence shows 48% identity to the first identified Arabidopsis Ggamma-subunit, AGG1. Furthermore, AGG2 contains all of the conserved characteristics of gamma-subunits including a small size (100 amino acids, 11.1 kDa), C-terminal CAAX box and a N-terminal alpha-helix region capable of forming a coiled-coil interaction with the beta-subunit. A strong interaction between AGG2 and both the tobacco (TGB1) and Arabidopsis (AGB1) beta-subunits was observed in vivo using the yeast two-hybrid system. The strong association between AGG2 and AGB1 was confirmed in vitro. Southern and Northern analyses showed that AGG2 is a single copy gene in Arabidopsis producing two transcripts that are present in all tissues tested. The isolation of a second gamma-subunit from A. thaliana indicates that plant G-proteins, like their mammalian counterparts, may form different heterotrimer combinations that presumably regulate multiple signal transduction pathways.
Can heterotrimeric G proteins help to feed the world?
Publisher: Elsevier BV
Date: 10-2012
DOI: 10.1016/J.TPLANTS.2012.06.002
Abstract: Recently, two important yield quantitative trait loci (QTLs), GS3 and DEP1, have been cloned in rice (Oryza sativa). Although their relationship has not been established in the 'rice literature', a recent report identified them as heterotrimeric G protein γ subunits. This identification has profound consequences for our current understanding of both QTLs and the plant G protein signaling network and this opinion article discusses how manipulation of G protein signaling may lead to yield improvements in rice and other crop species. Finally, a mechanistic model to explain the seemingly conflicting phenotypes produced by different GS3 and DEP1 alleles is proposed.
A simple and cost-effective method for screening of CRISPR/Cas9-induced homozygous/biallelic mutants
Publisher: Springer Science and Business Media LLC
Date: 29-05-2018
Field Demonstration of a Multiplexed Point-of-Care Diagnostic Platform for Plant Pathogens
Publisher: American Chemical Society (ACS)
Date: 27-07-2016
DOI: 10.1021/ACS.ANALCHEM.6B01551
Abstract: Effective disease management strategies to prevent catastrophic crop losses require rapid, sensitive, and multiplexed detection methods for timely decision making. To address this need, a rapid, highly specific and sensitive point-of-care method for multiplex detection of plant pathogens was developed by taking advantage of surface-enhanced Raman scattering (SERS) labeled nanotags and recombinase polymerase lification (RPA), which is a rapid isothermal lification method with high specificity. In this study, three agriculturally important plant pathogens (Botrytis cinerea, Pseudomonas syringae, and Fusarium oxysporum) were used to demonstrate potential translation into the field. The RPA-SERS method was faster, more sensitive than polymerase chain reaction, and could detect as little as 2 copies of B. cinerea DNA. Furthermore, multiplex detection of the three pathogens was demonstrated for complex systems such as the Arabidopsis thaliana plant and commercial tomato crops. To demonstrate the potential for on-site field applications, a rapid single-tube RPA/SERS assay was further developed and successfully performed for a specific target outside of a laboratory setting.
TALEN-mediated targeted mutagenesis produces a large variety of heritable mutations in rice
Publisher: Wiley
Date: 13-04-2016
DOI: 10.1111/PBI.12372
Abstract: CRISPR/Cas9 and TALEN are currently the two systems of choice for genome editing. We have studied the efficiency of the TALEN system in rice as well as the nature and inheritability of TALEN-induced mutations and found important features of this technology. The N287C230 TALEN backbone resulted in low mutation rates (0-6.6%), but truncations in its C-terminal domain dramatically increased efficiency to 25%. In most transgenic T0 plants, TALEN produced a single prevalent mutation accompanied by a variety of low-frequency mutations. For each independent T0 plant, the prevalent mutation was present in most tissues within a single tiller as well as in all tillers examined, suggesting that TALEN-induced mutations occurred very early in the development of the shoot apical meristem. Multigenerational analysis showed that TALEN-induced mutations were stably transmitted to the T1 and T2 populations in a normal Mendelian fashion. In our study, the vast majority of TALEN-induced mutations (~81%) affected multiple bases and ~70% of them were deletions. Our results contrast with published reports for the CRISPR/Cas9 system in rice, in which the predominant mutations affected single bases and deletions accounted for only 3.3% of the overall mutations.
Modulation of higher-plant NAD(H)-dependent glutamate dehydrogenase activity in transgenic tobacco via alteration of beta subunit levels
Publisher: Springer Science and Business Media LLC
Date: 04-2005
DOI: 10.1007/S00425-005-1510-Z
Abstract: Glutamate dehydrogenase (GDH EC 1.4.1.2-1.4.1.4) catalyses in vitro the reversible amination of 2-oxoglutarate to glutamate. In vascular plants the in vivo direction(s) of the GDH reaction and hence the physiological role(s) of this enzyme remain obscure. A phylogenetic analysis identified two clearly separated groups of higher-plant GDH genes encoding either the alpha- or beta-subunit of the GDH holoenzyme. To help clarify the physiological role(s) of GDH, tobacco (Nicotiana tabacum L.) was transformed with either an antisense or sense copy of a beta-subunit gene, and transgenic plants recovered with between 0.5- and 34-times normal leaf GDH activity. This large modulation of GDH activity (shown to be via alteration of beta-subunit levels) had little effect on leaf ammonium or the leaf free amino acid pool, except that a large increase in GDH activity was associated with a significant decrease in leaf Asp (~51%, P=0.0045). Similarly, plant growth and development were not affected, suggesting that a large modulation of GDH beta-subunit titre does not affect plant viability under the ideal growing conditions employed. Reduction of GDH activity and protein levels in an antisense line was associated with a large increase in transcripts of a beta-subunit gene, suggesting that the reduction in beta-subunit levels might have been due to translational inhibition. In another experiment designed to detect post-translational up-regulation of GDH activity, GDH over-expressing plants were subjected to prolonged dark-stress. GDH activity increased, but this was found to be due more likely to resistance of the GDH protein to stress-induced proteolysis, rather than to post-translational up-regulation.
Identification and characterization of a full-length cDNA encoding for an auxin-induced 1-aminocyclopropane-1-carboxylate synthase from etiolated mung bean hypocotyl segments and expression of its mRNA in response to indole-3-acetic acid
Publisher: Springer Science and Business Media LLC
Date: 11-1992
DOI: 10.1007/BF00040602
Abstract: To define the changes in demographics of liver injury during the past 25 years and to document the impact of treatment changes on death rates. No study has presented a long-term review of a large series of hepatic injuries, documenting the effect of treatment changes on outcome. A 25-year review from a concurrently collected database of liver injuries documented changes in treatment and outcome. A database of hepatic injuries from 1975 to 1999 was studied for changes in demographics, treatment patterns, and outcome. Factors potentially responsible for outcome differences were examined. A total of 1,842 liver injuries were treated. Blunt injuries have dramatically increased the proportion of major injuries is approximately 16% annually. Nonsurgical therapy is now used in more than 80% of blunt injuries. The death rates from both blunt and penetrating trauma have improved significantly through each successive decade of the study. The improved death rates are due to decreased death from hemorrhage. Factors responsible include fewer major venous injuries requiring surgery, improved outcome with vein injuries, better results with packing, and effective arterial hemorrhage control with arteriographic embolization. The treatment and outcome of liver injuries have changed dramatically in 25 years. Multiple modes of therapy are available for hemorrhage control, which has improved outcome.
Immunocytolocalization of glutamine synthetase in green leaves and cotyledons of Lycopersicon esculentum
Publisher: No publisher found
Date: 1988
A Highly Efficient Cell Division-Specific CRISPR/Cas9 System Generates Homozygous Mutants for Multiple Genes in Arabidopsis
Publisher: MDPI AG
Date: 07-12-2018
DOI: 10.3390/IJMS19123925
Abstract: The CRISPR/Cas9 system has been widely used for targeted genome editing in numerous plant species. In Arabidopsis, constitutive promoters usually result in a low efficiency of heritable mutation in the T1 generation. In this work, CRISPR/Cas9 gene editing efficiencies using different promoters to drive Cas9 expression were evaluated. Expression of Cas9 under the constitutive CaMV 35S promoter resulted in a 2.3% mutation rate in T1 plants and failed to produce homozygous mutations in the T1 and T2 generations. In contrast, expression of Cas9 under two cell ision-specific promoters, YAO and CDC45, produced mutation rates of 80.9% to 100% in the T1 generation with nonchimeric mutations in the T1 (4.4–10%) and T2 (32.5–46.1%) generations. The pCDC45 promoter was used to modify a previously reported multiplex CRISPR/Cas9 system, replacing the original constitutive ubiquitin promoter. The multi-pCDC45-Cas9 system produced higher mutation efficiencies than the multi-pUBQ-Cas9 system in the T1 generation (60.17% vs. 43.71%) as well as higher efficiency of heritable mutations (11.30% vs. 4.31%). Sextuple T2 homozygous mutants were identified from a construct targeting seven in idual loci. Our results demonstrate the advantage of using cell ision promoters for CRISPR/Cas9 gene editing applications in Arabidopsis, especially in multiplex applications.
VERNALIZATION1 Modulates Root System Architecture in Wheat and Barley
Publisher: Elsevier BV
Date: 2018
A mechanical strain-induced 1-aminocyclopropane-1-carboxylic acid synthase gene
Publisher: Proceedings of the National Academy of Sciences
Date: 28-02-1995
Abstract: Ethylene production is observed in all higher plants, where it is involved in numerous aspects of growth, development, and senescence. 1-Aminocyclopropane-1-carboxylic acid synthase (ACC synthase S-adenosyl-L-methionine methylthioadenosine-lyase, EC 4.4.1.14) is the key regulatory enzyme in the ethylene biosynthetic pathway. We are reporting an ACC synthase gene in Vigna radiata (mung bean) that is inducible by mechanical strain. The ACC synthase cDNA AIM-1 was induced by mechanical strain within 10 min, reaching a maximum at 30 min, showing a dramatic reduction after 60 min, and showing no detectable message by 3 hr. The kinetics of induction for AIM-1 was similar to a mechanical strain-induced calmodulin (MBCaM-1) in V. radiata, whereas the kinetics of its decline from maximum was different. When plants were subjected to calcium-deficient conditions, supplemental calcium, calcium chelators, calcium storage releasers, calcium ionophore, or calmodulin antagonists, there was no effect on AIM-1, indicating that the mechanical strain-induced AIM-1 expression is a calcium-independent process. Induction of MBCaM-1 in all cases behaved in the same way as AIM-1, suggesting that they share similar mechanically activated cis- and/or trans-acting elements in their promoter.
Site-directed mutagenesis of the Arabidopsis heterotrimeric G protein β subunit suggests divergent mechanisms of effector activation between plant and animal G proteins
Publisher: Springer Science and Business Media LLC
Date: 15-10-2011
DOI: 10.1007/S00425-011-1526-5
Abstract: Heterotrimeric G proteins are integral components of signal transduction in humans and other mammals and have been therefore extensively studied. However, while they are known to mediate many processes, much less is currently known about the effector pathways and molecular mechanisms used by these proteins to regulate effectors in plants. We designed a complementation strategy to study G protein signaling in Arabidopsis thaliana, particularly the mechanism of action of AGB1, the sole identified β subunit. We used biochemical and effector regulation data from human G protein studies to identify four potentially important residues for site-directed mutagenesis (T65, M111, D250 and W361 of AGB1). Each residue was in idually mutated and the resulting mutated protein introduced in the agb1-2 mutant background under the control of the native AGB1 promoter. Interestingly, even though these mutations have been shown to have profound effects on effector signaling in humans, all the mutated subunits were able to restore thirteen of the fifteen Gβ-deficient phenotypes characterized in this study. Only one mutated protein, T65A was unable to complement the hypersensitivity to mannitol during germination observed in agb1 mutants while only D250A failed to restore lateral root numbers in the agb1 mutant to wild-type levels. Our results suggest that the mechanisms used in mammalian G protein signaling are not well conserved in plant G protein signaling, and that either the effectors used by plant G proteins, or the mechanisms used to activate them, are at least partially ergent from the well-studied mammalian G proteins.
An atypical heterotrimeric G‐protein γ‐subunit is involved in guard cell K+‐channel regulation and morphological development in Arabidopsis thaliana
Publisher: Wiley
Date: 24-06-2011
Gγ1 + Gγ2 ≠ Gβ: Heterotrimeric G Protein Gγ-Deficient Mutants Do Not Recapitulate All Phenotypes of Gβ-Deficient Mutants
Publisher: Oxford University Press (OUP)
Date: 25-04-2008
Abstract: Heterotrimeric G proteins are signaling molecules ubiquitous among all eukaryotes. The Arabidopsis (Arabidopsis thaliana) genome contains one Gα (GPA1), one Gβ (AGB1), and two Gγ subunit (AGG1 and AGG2) genes. The Gβ requirement of a functional Gγ subunit for active signaling predicts that a mutant lacking both AGG1 and AGG2 proteins should phenotypically resemble mutants lacking AGB1 in all respects. We previously reported that Gβ- and Gγ-deficient mutants coincide during plant pathogen interaction, lateral root development, gravitropic response, and some aspects of seed germination. Here, we report a number of phenotypic discrepancies between Gβ- and Gγ-deficient mutants, including the double mutant lacking both Gγ subunits. While Gβ-deficient mutants are hypersensitive to abscisic acid inhibition of seed germination and are hyposensitive to abscisic acid inhibition of stomatal opening and guard cell inward K+ currents, none of the available Gγ-deficient mutants shows any deviation from the wild type in these responses, nor do they show the hypocotyl elongation and hook development defects that are characteristic of Gβ-deficient mutants. In addition, striking discrepancies were observed in the aerial organs of Gβ- versus Gγ-deficient mutants. In fact, none of the distinctive traits observed in Gβ-deficient mutants (such as reduced size of cotyledons, leaves, flowers, and siliques) is present in any of the Gγ single and double mutants. Despite the considerable amount of phenotypic overlap between Gβ- and Gγ-deficient mutants, confirming the tight relationship between Gβ and Gγ subunits in plants, considering the significant differences reported here, we hypothesize the existence of new and as yet unknown elements in the heterotrimeric G protein signaling complex.
Immunocytolocalization of Glutamine Synthetase in Green Leaves and Cotyledons of Lycopersicon esculentum
Publisher: Oxford University Press (OUP)
Date: 11-1988
DOI: 10.1104/PP.88.3.943
Phylogenomic and Functional Analysis of Pterin-4a-Carbinolamine Dehydratase Family (COG2154) Proteins in Plants and Microorganisms
Publisher: Oxford University Press (OUP)
Date: 02-2008
Abstract: Pterin-4a-carbinolamine dehydratases (PCDs) recycle oxidized pterin cofactors generated by aromatic amino acid hydroxylases (AAHs). PCDs are known biochemically only from animals and one bacterium, but PCD-like proteins (COG2154 in the Clusters of Orthologous Groups [COGs] database) are encoded by many plant and microbial genomes. Because these genomes often encode no AAH homologs, the annotation of their COG2154 proteins as PCDs is questionable. Moreover, some COG2154 proteins lack canonical residues that are catalytically important in mammalian PCDs. Diverse COG2154 proteins of plant, fungal, protistan, and prokaryotic origin were therefore tested for PCD activity by functional complementation in Escherichia coli, and the plant proteins were localized using green fluorescent protein fusions. Higher and lower plants proved to have two COG2154 proteins, a mitochondrial one with PCD activity and a noncanonical, plastidial one without. Phylogenetic analysis indicated that the latter is unique to plants and arose from the former early in the plant lineage. All 10 microbial COG2154 proteins tested had PCD activity six of these came from genomes with no AAH, and six were noncanonical. The results suggested the motif [EDKH]-x(3)-H-[HN]-[PCS]-x(5,6)-[YWF]-x(9)-[HW]-x(8,15)-D as a signature for PCD activity. Organisms having a functional PCD but no AAH partner include angiosperms, yeast, and various prokaryotes. In these cases, PCD presumably has another function. An ancillary role in molybdopterin cofactor metabolism, hypothesized from phylogenomic evidence, was supported by demonstrating significantly lowered activities of two molybdoenzymes in Arabidopsis thaliana PCD knockout mutants. Besides this role, we propose that partnerless PCDs support the function of as yet unrecognized pterin-dependent enzymes.
Whole-Genome Analysis of Candidate genes Associated with Seed Size and Weight in Sorghum bicolor Reveals Signatures of Artificial Selection and Insights into Parallel Domestication in Cereal Crops
Publisher: Frontiers Media SA
Date: 18-07-2017
Heritability of targeted gene modifications induced by plant-optimized CRISPR systems
Publisher: Springer Science and Business Media LLC
Date: 27-09-2016
DOI: 10.1007/S00018-016-2380-1
Abstract: The Streptococcus-derived CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)/Cas9 (CRISPR-associated protein 9) system has emerged as a very powerful tool for targeted gene modifications in many living organisms including plants. Since the first application of this system for plant gene modification in 2013, this RNA-guided DNA endonuclease system has been extensively engineered to meet the requirements of functional genomics and crop trait improvement in a number of plant species. Given its short history, the emphasis of many studies has been the optimization of the technology to improve its reliability and efficiency to generate heritable gene modifications in plants. Here we review and analyze the features of customized CRISPR/Cas9 systems developed for plant genetic studies and crop breeding. We focus on two essential aspects: the heritability of gene modifications induced by CRISPR/Cas9 and the factors affecting its efficiency, and we provide strategies for future design of systems with improved activity and heritability in plants.
Characterization of ATDRG1, a member of a new class of GTP-binding proteins in plants.
Publisher: Springer Science and Business Media LLC
Date: 1999
Abstract: We report the initial characterization of an Arabidopsis thaliana cDNA (atdrg1), a member of a new class of GTP-binding proteins (G-proteins) in plants. The predicted ATDRG1 protein contains all five structural motifs characteristic of the G-protein superfamily. Apart from these motifs, the amino acid sequence differs substantially from all known G-proteins except for a recently discovered new family named developmentally regulated G-proteins (DRGs). Sequences closely related to atdrg1 are found in species as distant as human (80% amino acid conservation), Drosophila (74%), yeast (77%) and Caenorhabditis elegans (77%). The remarkable evolutionary conservation of these proteins suggests an important, but as yet unclear role. Phylogenetic analysis of the available homologous sequences strongly suggests a diphyletic origin of the eukaryotic DRG proteins. Northern analysis shows high levels of atdrg1 mRNA in all Arabidopsis tissues studied, and homologues of atdrg1 are present throughout the plant kingdom. In situ hybridization reveals that atdrg1 is highly expressed in actively growing tissues and reproductive organs. Southern analysis indicates the presence of either one or two copies of atdrg1 in the Arabidopsis genome. Immunolocalization studies show that the protein is present in cytoplasmic vesicles found mainly in actively growing tissues suggesting a putative role for ATDRG1 in either the regulation of vesicle transport or the regulation of enzymes involved in storage protein processing.
Rapid isolation of high-quality RNA from symbiotic dinoflagellates
Publisher: Informa UK Limited
Date: 07-1998
Re-evaluation of the cytokinin receptor role of the Arabidopsis gene GCR1
Publisher: Elsevier BV
Date: 2001
Identification and Characterisation of Two 1-Aminocyclopropane- 1-Carboxylate (ACC) Synthase cDNAs Expressed during Papaya (Carica papaya) Fruit Ripening
Publisher: CSIRO Publishing
Date: 1997
DOI: 10.1071/PP96111
Abstract: The cloning and characterisation of two cDNAs (capacs1 and capacs2) encoding ACC synthase in papaya (Carica papaya L.) is described. capacs1 is 1104 bp long encoding 368 amino acids. capacs2 is 1098 bp long encoding 366 amino acids. The proteins encoded by both cDNAs contain the highly conserved active site of ACC synthases as well as 10 (capacs1) or 11 (capacs2) of the 12 amino acid residues conserved in most aminotransferases. Southern analyses indicate that capacs1 and capacs2 are present in the papaya genome as single copy genes. Both genes show very different expression patterns during fruit ripening. capacs1 mRNA levels are high in mature green fruits, decreasing steadily during ripening, whereas capacs2 mRNA levels are undetectable in mature green fruits but experience a dramatic increase with the onset of ripening and remain high throughout the various stages of ripening.
Cloning and characterisation of ripening-induced ethylene biosynthetic genes from non-climacteric pineapple (Ananas comosus) fruits
Publisher: CSIRO Publishing
Date: 1998
DOI: 10.1071/PP98013
Abstract: To gain a better understanding of non-climacteric fruit ripening, pineapple was used as a model system to clone and characterise two ripening-inducible cDNAs coding for two enzymes of the ethylene biosynthetic pathway, 1-aminocyclopropane-1-carboxylate (ACC) synthase (acacc-1) and 1-aminocyclo-propane- 1-carboxylate oxidase (acaco-1) respectively. Due to the extreme acidity and high polyphenolic content of pineapple fruits, a method was optimised for the extraction of high quality RNA from fruit tissue. acacc-1 is a 1080 bp ACC synthase cDNA fragment encoding 360 amino acids including 10 of the 12 amino acid residues conserved in all aminotransferases. Comparison of the deduced amino acid sequence with previously reported ACC synthases shows between 52 and 67% similarity at the protein level. Southern analysis suggests the presence of only one copy of acacc-1 in the pineapple genome. Although some acacc-1 expression is detected in green fruits, there is a 16-fold increase in the level of acacc-1 in ripe fruit tissue. acaco-1 is a partial length cDNA clone of 611 bp which codes for 203 amino acids representing approximately 66% of the ACC oxidase open reading frame. Southern analysis suggests the presence of one or two copies of the gene in the pineapple genome. Northern analysis shows the expression of acaco-1 to be highly induced in wounded leaf tissue and to a lesser extent in ripening fruit tissue. The accumulation of ACC-synthase and ACC oxidase mRNAs during pineapple fruit ripening raises new questions about the putative role of ethylene during non-climacteric fruit ripening.
Completing the heterotrimer: Isolation and characterization of an Arabidopsis thaliana G protein γ-subunit cDNA
Publisher: Proceedings of the National Academy of Sciences
Date: 19-12-2000
Abstract: Heterotrimeric G proteins consist of three subunits (α, β, and γ). α- and β- subunits have been previously cloned in plants, but the γ-subunit has remained elusive. To isolate the γ-subunit of a plant heterotrimeric G protein an Arabidopsis thaliana yeast two-hybrid library was screened by using a tobacco G-β-subunit as the bait protein. One positive clone ( AGG1 ) was isolated several times it displays significant homology to the conserved domains of mammalian γ-subunits. The predicted AGG1 protein sequence contains all of the typical characteristics of mammalian γ-subunits such as small size (98 amino acids, 10.8 kDa), presence of a C-terminal CAAX box to direct isoprenyl modification, and an N-terminal α-helix region capable of forming a coiled-coil interaction with the β-subunit. Northern and Southern analyses showed that AGG1 is a single-copy gene in Arabidopsis with a similar expression pattern to the Arabidopsis β-subunit, AGB1 [Weiss, C. A., Garnaat, C. W., Mukai, K., Hu, Y. & Ma, H. (1994) Proc. Natl. Acad. Sci. USA 91, 9554–9558]. By using the yeast two-hybrid system, we show that AGG1 strongly interacts with tobacco and Arabidopsis β-subunits. The in vivo results have been confirmed by using in vitro methods to prove the interaction between AGG1 and the Arabidopsis β-subunit. As previously observed in mammalian systems, both the coiled-coil domain and the WD repeat regions of the β-subunit are essential for AGG1 interaction. Also in agreement with previous observations, the removal of the N-terminal α-helix of the AGG1 greatly reduces but does not completely block the interaction.
Immunochemical Comparison of Glutamine Synthetases from Some Solanaceae Plants
Publisher: Oxford University Press (OUP)
Date: 10-1986
DOI: 10.1104/PP.82.2.585
GTP binding by Arabidopsis extra-large G protein 2 is not essential for its functions
Publisher: Oxford University Press (OUP)
Date: 17-03-2021
Abstract: The extra-large guanosine-5′-triphosphate (GTP)-binding protein 2, XLG2, is an unconventional Gα subunit of the Arabidopsis (Arabidopsis thaliana) heterotrimeric GTP-binding protein complex with a major role in plant defense. In vitro biochemical analyses and molecular dynamic simulations show that affinity of XLG2 for GTP is two orders of magnitude lower than that of the conventional Gα, AtGPA1. Here we tested the physiological relevance of GTP binding by XLG2. We generated an XLG2(T476N) variant with abolished GTP binding, as confirmed by in vitro GTPγS binding assay. Yeast three-hybrid, bimolecular fluorescence complementation, and split firefly-luciferase complementation assays revealed that the nucleotide-depleted XLG2(T476N) retained wild-type XLG2-like interactions with the Gβγ dimer and defense-related receptor-like kinases. Both wild-type and nucleotide-depleted XLG2(T476N) restored the defense responses against Fusarium oxysporum and Pseudomonas syringae compromised in the xlg2 xlg3 double mutant. Additionally, XLG2(T476N) was fully functional restoring stomatal density, root growth, and sensitivity to NaCl, but failed to complement impaired germination and vernalization-induced flowering. We conclude that XLG2 is able to function in a GTP-independent manner and discuss its possible mechanisms of action.
Abscisic acid-induced cytoplasmic translocation of constitutive photomorphogenic 1 enhances reactive oxygen species accumulation through the HY5-ABI5 pathway to modulate seed germination.
Publisher: Wiley
Date: 10-03-2022
DOI: 10.1111/PCE.14298
Abstract: Seed germination is a physiological process regulated by multiple factors. Abscisic acid (ABA) can inhibit seed germination to improve seedling survival under conditions of abiotic stress, and this process is often regulated by light signals. Constitutive photomorphogenic 1 (COP1) is an upstream core repressor of light signals and is involved in several ABA responses. Here, we demonstrate that COP1 is a negative regulator of the ABA-mediated inhibition of seed germination. Disruption of COP1 enhanced Arabidopsis seed sensitivity to ABA and increased reactive oxygen species (ROS) levels. In seeds, ABA induced the translocation of COP1 to the cytoplasm, resulting in enhanced ABA-induced ROS levels. Genetic evidence indicated that HY5 and ABI5 act downstream of COP1 in the ABA-mediated inhibition of seed germination. ABA-induced COP1 cytoplasmic localization increased HY5 and ABI5 protein levels in the nucleus, leading to increased expression of ABI5 target genes and ROS levels in seeds. Together, our results reveal that ABA-induced cytoplasmic translocation of COP1 activates the HY5-ABI5 pathway to promote the expression of ABA-responsive genes and the accumulation of ROS during ABA-mediated inhibition of seed germination. These findings enhance the role of COP1 in the ABA signal transduction pathway.
Now for the hard ones: is there a limit on CRISPR genome editing in crops?
Publisher: Oxford University Press (OUP)
Date: 30-01-2019
DOI: 10.1093/JXB/ERZ007
Different Characteristics of the Two Glutamate Synthases in the Green Leaves of Lycopersicon esculentum
Publisher: Oxford University Press (OUP)
Date: 12-1987
DOI: 10.1104/PP.85.4.1036
Generation of new glutinous rice by CRISPR/Cas9-targeted mutagenesis of the Waxy gene in elite rice varieties
Publisher: Wiley
Date: 23-01-2018
DOI: 10.1111/JIPB.12620
Genome Editing in Cotton with the CRISPR/Cas9 System
Publisher: Frontiers Media SA
Date: 03-08-2017
Erratum: Modulation of higher-plant NAD(H)-dependent glutamate dehydrogenase activity in transgenic tobacco via alteration of beta subunit levels (Planta 222, (167-180) DOI: 10.1007/s00425-005-1510-z)
Publisher: Springer Science and Business Media LLC
Date: 08-02-2007
COP1 promotes ABA‐induced stomatal closure by modulating the abundance of ABI/HAB and AHG3 phosphatases
Publisher: Wiley
Date: 16-12-2020
DOI: 10.1111/NPH.17001
PineappleDB: An online pineapple bioinformatics resource
Publisher: Springer Science and Business Media LLC
Date: 05-10-2005
Abstract: A world first pineapple EST sequencing program has been undertaken to investigate genes expressed during non-climacteric fruit ripening and the nematode-plant interaction during root infection. Very little is known of how non-climacteric fruit ripening is controlled or of the molecular basis of the nematode-plant interaction. PineappleDB was developed to provide the research community with access to a curated bioinformatics resource housing the fruit, root and nematode infected gall expressed sequences. PineappleDB is an online, curated database providing integrated access to annotated expressed sequence tag (EST) data for cDNA clones isolated from pineapple fruit, root, and nematode infected root gall vascular cylinder tissues. The database currently houses over 5600 EST sequences, 3383 contig consensus sequences, and associated bioinformatic data including splice variants, Arabidopsis homologues, both MIPS based and Gene Ontology functional classifications, and clone distributions. The online resource can be searched by text or by BLAST sequence homology. The data outputs provide comprehensive sequence, bioinformatic and functional classification information. The online pineapple bioinformatic resource provides the research community with access to pineapple fruit and root/gall sequence and bioinformatic data in a user-friendly format. The search tools enable efficient data mining and present a wide spectrum of bioinformatic and functional classification information. PineappleDB will be of broad appeal to researchers investigating pineapple genetics, non-climacteric fruit ripening, root-knot nematode infection, crassulacean acid metabolism and alternative RNA splicing in plants.
Evidence for an unusual transmembrane configuration of AGG3, a class C Gγ subunit of Arabidopsis
Publisher: Wiley
Date: 22-12-2014
DOI: 10.1111/TPJ.12732
Progress in the development of transgenic papaya: Transformation of Solo Papaya using ACC synthase antisense construct
Publisher: International Society for Horticultural Science (ISHS)
Date: 04-2002
Cloning and molecular characterization of ripening-related ACC synthase from papaya fruit (Carica papaya L.)
Publisher: International Society for Horticultural Science (ISHS)
Date: 04-2002
Gene editing in plants: progress and challenges
Publisher: Oxford University Press (OUP)
Date: 17-01-2019
DOI: 10.1093/NSR/NWZ005
Abstract: The clustered regularly interspaced short palindromic repeat (CRISPR)-associated protein 9 (Cas9) genome editing system is a powerful tool for targeted gene modifications in a wide range of species, including plants. Over the last few years, this system has revolutionized the way scientists perform genetic studies and crop breeding, due to its simplicity, flexibility, consistency and high efficiency. Considerable progress has been made in optimizing CRISPR/Cas9 systems in plants, particularly for targeted gene mutagenesis. However, there are still a number of important challenges ahead, including methods for the efficient delivery of CRISPR and other editing tools to most plants, and more effective strategies for sequence knock-ins and replacements. We provide our viewpoint on the goals, potential concerns and future challenges for the development and application of plant genome editing tools.
TISSUE-SPECIFIC EXPRESSION OF A GENE ENCODING A CELL WALL-LOCALIZED LIPID TRANSFER PROTEIN FROM ARABIDOPSIS
Publisher: Oxford University Press (OUP)
Date: 05-1994
DOI: 10.1104/PP.105.1.35
Abstract: Nonspecific lipid transfer proteins (LTPs) from plants are characterized by their ability to stimulate phospholipid transfer between membranes in vitro. However, because these proteins are generally located outside of the plasma membrane, it is unlikely that they have a similar role in vivo. As a step toward identifying the function of these proteins, one of several LTP genes from Arabidoposis has been cloned and the expression pattern of the gene has been examined by analysis of the tissue specificity of beta-glucuronidase (GUS) activity in transgenic plants containing LTP promoter-GUS fusions and by in situ mRNA localization. The LTP1 promoter was active early in development in protoderm cells of embryos, vascular tissues, lignified tips of cotyledons, shoot meristem, and stipules. In adult plants, the gene was expressed in epidermal cells of young leaves and the stem. In flowers, expression was observed in the epidermis of all developing influorescence and flower organ primordia, the epidermis of the siliques and the outer ovule wall, the stigma, petal tips, and floral nectaries of mature flowers, and the petal/sepal abscission zone of mature siliques. The presence of GUS activity in guard cells, lateral roots, pollen grains, leaf vascular tissue, and internal cells of stipules and nectaries was not confirmed by in situ hybridizations, supporting previous observations that suggest that the reporter gene is subject to artifactual expression. These results are consistent with a role for the LTP1 gene product in some aspect of secretion or deposition of lipophilic substances in the cell walls of expanding epidermal cells and certain secretory tissues. The LTP1 promoter region contained sequences homologous to putative regulatory elements of genes in the phenylpropanoid biosynthetic pathway, suggesting that the expression of the LTP1 gene may be regulated by the same or similar mechanisms as genes in the phenylpropanoid pathway.
The gland localized CGP1 controls gland pigmentation and gossypol accumulation in cotton
Publisher: Wiley
Date: 21-01-2020
DOI: 10.1111/PBI.13323
Yeast Three-Hybrid System for the Detection of Protein-Protein Interactions
Publisher: Springer New York
Date: 2016
DOI: 10.1007/978-1-4939-3115-6_12
Abstract: Protein-protein interaction studies provide useful insights into biological processes taking place within the living cell. A number of techniques are available to unravel large structural protein complexes, functional protein modules, and temporary protein associations occurring during signal transduction. The choice of method depends on the nature of the proteins and the interaction being studied. Here we present an optimized and simplified yeast three-hybrid method for analysis of protein interactions involving three components.
Dissecting Arabidopsis Gβ Signal Transduction on the Protein Surface
Publisher: Oxford University Press (OUP)
Date: 08-05-2012
Abstract: The heterotrimeric G-protein complex provides signal lification and target specificity. The Arabidopsis (Arabidopsis thaliana) Gβ-subunit of this complex (AGB1) interacts with and modulates the activity of target cytoplasmic proteins. This specificity resides in the structure of the interface between AGB1 and its targets. Important surface residues of AGB1, which were deduced from a comparative evolutionary approach, were mutated to dissect AGB1-dependent physiological functions. Analysis of the capacity of these mutants to complement well-established phenotypes of Gβ-null mutants revealed AGB1 residues critical for specific AGB1-mediated biological processes, including growth architecture, pathogen resistance, stomata-mediated leaf-air gas exchange, and possibly photosynthesis. These findings provide promising new avenues to direct the finely tuned engineering of crop yield and traits.
Heterotrimeric G proteins-mediated resistance to necrotrophic pathogens includes mechanisms independent of salicylic acid-, jasmonic acid/ethylene- and abscisic acid-mediated defense signaling.
Publisher: Wiley
Date: 26-03-2008
Whole Genome Sequencing Reveals Potential New Targets for Improving Nitrogen Uptake and Utilization in Sorghum bicolor
Publisher: Frontiers Media SA
Date: 25-10-2016
Biosynthesis of DHGA12 and its roles in Arabidopsis seedling establishment
Publisher: Springer Science and Business Media LLC
Date: 16-04-2019
DOI: 10.1038/S41467-019-09467-5
Abstract: Seed germination and photoautotrophic establishment are controlled by the antagonistic activity of the phytohormones gibberellins (GAs) and abscisic acid (ABA). Here we show that Arabidopsis thaliana GAS2 (Gain of Function in ABA-modulated Seed Germination 2), a protein belonging to the Fe-dependent 2-oxoglutarate dioxygenase superfamily, catalyzes the stereospecific hydration of GA 12 to produce GA 12 16, 17-dihydro-16α-ol (DHGA 12 ). We show that DHGA 12 , a C 20 -GA has an atypical structure compared to known active GAs but can bind to the GA receptor (GID1c). DHGA 12 can promote seed germination, hypocotyl elongation and cotyledon greening. Silencing and over-expression of GAS2 alters the ABA/GA ratio and sensitivity to ABA during seed germination and photoautotrophic establishment. Hence, we propose that GAS2 acts to modulate hormonal balance during early seedling development.
E3 ligases MAC3A and MAC3B ubiquitinate UBIQUITIN-SPECIFIC PROTEASE14 to regulate organ size in Arabidopsis
Publisher: Oxford University Press (OUP)
Date: 18-10-2023
A novel temperature-sensitive immune pathway in plants
Publisher: Research Square Platform LLC
Date: 03-03-2023
DOI: 10.21203/RS.3.RS-2567147/V1
Abstract: The immune system is crucial for plant survival, although its activation erts resources away from other important processes, such as growth and reproduction. To balance the need for an effective immune response with the need to maintain overall fitness, plants have evolved immune priming. The priming or pre-activation of defence mechanisms allows plant cells to respond faster and more efficiently to an incoming threat without triggering the actual defence response. In this study, we reveal a novel molecular mechanism of temperature dependent immune priming mediated by the Arabidopsis extra-large GTP binding protein 2 (XLG2) contributing to resistance against pathogens such as Fusarium oxysporum and Pseudomonas syringae . We found that XLG2 rapidly accumulates in the nucleus upon temperature elevation and that nuclear localization is essential for XLG2-mediated defence responses. XLG2 directly interacts with several defence-related transcription factors and stabilizes transcription activation complexes, such as nonexpressor of pathogenesis related genes 1 (NPR1) and TGACG sequence-specific binding protein (TGA2). Our observations suggest that XLG2 integrates abiotic and biotic stress signals providing an important balance between immunity and fitness and thus enabling plants to adequately respond to a changing environment.
Type B Heterotrimeric G Protein γ-Subunit Regulates Auxin and ABA Signaling in Tomato
Publisher: Oxford University Press (OUP)
Date: 14-12-2015
DOI: 10.1104/PP.15.01675
ABC1K10a, an atypical kinase, functions in plant salt stress tolerance
Publisher: Springer Science and Business Media LLC
Date: 10-06-2020
DOI: 10.1186/S12870-020-02467-4
Abstract: ABC1K (Activity of BC1 complex Kinase) is an evolutionarily primitive atypical kinase family widely distributed among prokaryotes and eukaryotes. The ABC1K protein kinases in Arabidopsis are predicted to localize either to the mitochondria or chloroplasts, in which plastid-located ABC1K proteins are involved in the response against photo-oxidative stress and cadmium-induced oxidative stress. Here, we report that the mitochondria-localized ABC1K10a functions in plant salt stress tolerance by regulating reactive oxygen species (ROS). Our results show that the ABC1K10a expression is induced by salt stress, and the mutations in this gene result in overaccumulation of ROS and hypersensitivity to salt stress. Exogenous application of the ROS-scavenger GSH significantly represses ROS accumulation and rescues the salt hypersensitive phenotype of abc1k10a . ROS overaccumulation in abc1k10a mutants under salt stress is likely due to the defect in mitochondria electron transport chain. Furthermore, defects of several other mitochondria-localized ABC1K genes also result in salt hypersensitivity. Taken together, our results reveal that the mitochondria-located ABC1K10a regulates mitochondrial ROS production and is a positive regulator of salt tolerance in Arabidopsis.
Short tandem target mimic rice lines uncover functions of miRNAs in regulating important agronomic traits
Publisher: Proceedings of the National Academy of Sciences
Date: 05-2017
Abstract: Plant microRNAs (miRNAs) control intricate gene regulatory networks and have been implicated in important developmental switches and stress responses. Plant miRNAs have recently emerged as promising targets for crop improvement because they can control complex agronomic traits however, functional studies using reverse genetics have been h ered by practical difficulties. We have silenced 35 miRNA families in rice to generate a resource for discovering new functions of miRNAs and targets of agronomic improvements. As a proof of concept, we show that manipulation of a promising miRNA, miRNA398, leads to important yield improvements. Our findings also reveal important agronomic roles for several miRNAs.
Manipulating plant RNA-silencing pathways to improve the gene editing efficiency of CRISPR/Cas9 systems
Publisher: Springer Science and Business Media LLC
Date: 28-09-2018
Gγ1+Gγ2+Gγ3=Gβ: The search for heterotrimeric G-protein γ subunits in Arabidopsis is over
Publisher: Elsevier BV
Date: 03-2012
DOI: 10.1016/J.JPLPH.2011.11.010
Abstract: In Arabidopsis, heterotrimeric G-proteins consist of one Gα (GPA1), one Gβ (AGB1) and three Gγ (AGG1, AGG2 and AGG3) subunits. Gβ and Gγ subunits function as obligate heterodimers, therefore any phenotypes observed in Gβ-deficient mutants should be apparent in Gγ-deficient mutants. Nevertheless, the first two Gγ subunits discovered failed to explain many of the phenotypes shown by the agb1 mutants in Arabidopsis, prompting the search for additional Gγ subunits. The recent discovery of an additional, although quite atypical, Gγ subunit in Arabidopsis (AGG3) has helped to complete the picture and explains almost all of the missing agb1 'orphan' phenotypes. There is nevertheless still one unexplained phenotype, the reduction in rosette size reported for agb1, that has not been observed in any of the in idual agg mutants or the double agg1agg2 mutant. We have now created a triple gamma mutant (agg1agg2agg3) in Arabidopsis and show that it recapitulates the remaining 'orphan'agb1 phenotypes. Triple agg1agg2agg3 mutants show the reduction in rosette size previously observed in agb1 mutants. In addition we show that small differences in flower and silique size observed between agb1 and agg3 mutants are also accounted for by the triple agg1agg2agg3 mutant. Our results strongly suggest that there are no additional members of the G-protein family remaining to be discovered in Arabidopsis.
Silencing of the ACC synthase gene ACACS2 causes delayed flowering in pineapple [Ananas comosus (L.) Merr.]
Publisher: Oxford University Press (OUP)
Date: 06-09-2006
DOI: 10.1093/JXB/ERL167
Abstract: Flowering is a crucial developmental stage in the plant life cycle. A number of different factors, from environmental to chemical, can trigger flowering. In pineapple, and other bromeliads, it has been proposed that flowering is triggered by a small burst of ethylene production in the meristem in response to environmental cues. A 1-amino-cyclopropane-1-carboxylate synthase (ACC synthase) gene has been cloned from pineapple (ACACS2), which is induced in the meristem under the same environmental conditions that induce flowering. Two transgenic pineapple lines have been produced containing co-suppression constructs designed to down-regulate the expression of the ACACS2 gene. Northern analysis revealed that the ACACS2 gene was silenced in a number of transgenic plants in both lines. Southern hybridization revealed clear differences in the methylation status of silenced versus non-silenced plants by the inability of a methylation-sensitive enzyme to digest within the ACACS2 DNA extracted from silenced plants, indicating that methylation is the cause of the observed co-suppression of the ACACS2 gene. Flowering characteristics of the transgenic plants were studied under field conditions in South East Queensland, Australia. Flowering dynamics studies revealed significant differences in flowering behaviour, with transgenic plants exhibiting silencing showing a marked delay in flowering when compared with non-silenced transgenic plants and control non-transformed plants. It is argued that the ACACS2 gene is one of the key contributors towards triggering 'natural flowering' in mature pineapples under commercial field conditions.
Down-regulation of Fusarium oxysporum endogenous genes by Host-Delivered RNA interference enhances disease resistance
Publisher: Frontiers Media SA
Date: 20-01-2015
Signaling Specificity Provided by the Arabidopsis thaliana Heterotrimeric G-Protein γ Subunits AGG1 and AGG2 Is Partially but Not Exclusively Provided through Transcriptional Regulation
Publisher: Public Library of Science (PLoS)
Date: 08-03-2013
Microarray analysis of gene expression profiles in ripening pineapple fruits
Publisher: Springer Science and Business Media LLC
Date: 12-2012
Abstract: Pineapple ( Ananas comosus ) is a tropical fruit crop of significant commercial importance. Although the physiological changes that occur during pineapple fruit development have been well characterized, little is known about the molecular events that occur during the fruit ripening process. Understanding the molecular basis of pineapple fruit ripening will aid the development of new varieties via molecular breeding or genetic modification. In this study we developed a 9277 element pineapple microarray and used it to profile gene expression changes that occur during pineapple fruit ripening. Microarray analyses identified 271 unique cDNAs differentially expressed at least 1.5-fold between the mature green and mature yellow stages of pineapple fruit ripening. Among these 271 sequences, 184 share significant homology with genes encoding proteins of known function, 53 share homology with genes encoding proteins of unknown function and 34 share no significant homology with any database accession. Of the 237 pineapple sequences with homologs, 160 were up-regulated and 77 were down-regulated during pineapple fruit ripening. DAVID Functional Annotation Cluster (FAC) analysis of all 237 sequences with homologs revealed confident enrichment scores for redox activity, organic acid metabolism, metalloenzyme activity, glycolysis, vitamin C biosynthesis, antioxidant activity and cysteine peptidase activity, indicating the functional significance and importance of these processes and pathways during pineapple fruit development. Quantitative real-time PCR analysis validated the microarray expression results for nine out of ten genes tested. This is the first report of a microarray based gene expression study undertaken in pineapple. Our bioinformatic analyses of the transcript profiles have identified a number of genes, processes and pathways with putative involvement in the pineapple fruit ripening process. This study extends our knowledge of the molecular basis of pineapple fruit ripening and non-climacteric fruit ripening in general.
Bigger, firmer, riper. Biotechnological control of ripening in tropical fruits
Publisher: International Society for Horticultural Science (ISHS)
Date: 04-2002
Development of germ-line-specific CRISPR-Cas9 systems to improve the production of heritable gene modifications in Arabidopsis
Publisher: Wiley
Date: 11-09-2016
DOI: 10.1111/PBI.12468
Expanding the target range of base editing in plants without loss of efficiency by blocking RNA‐silencing
Publisher: Wiley
Date: 29-10-2021
DOI: 10.1111/PBI.13712
Host Delivered RNAi, an efficient approach to increase rice resistance to sheath blight pathogen (Rhizoctonia solani)
Publisher: Springer Science and Business Media LLC
Date: 08-08-2017
DOI: 10.1038/S41598-017-07749-W
Abstract: Rhizoctonia solani , the causal agent of rice sheath blight disease, causes significant losses worldwide as there are no cultivars providing absolute resistance to this fungal pathogen. We have used Host Delivered RNA Interference (HD-RNAi) technology to target two PATHOGENICITY MAP KINASE 1 ( PMK 1) homologues, RPMK 1-1 and RPMK 1-2, from R. solani using a hybrid RNAi construct. PMK 1 homologues in other fungal pathogens are essential for the formation of appressorium, the fungal infection structures required for penetration of the plant cuticle, as well as invasive growth once inside the plant tissues and overall viability of the pathogen within the plant. Evaluation of transgenic rice lines revealed a significant decrease in fungal infection levels compared to non-transformed controls and the observed delay in disease symptoms was further confirmed through microscopic studies. Relative expression levels of the targeted genes, RPMK 1-1 and RPMK 1-2, were determined in R. solani infecting either transgenic or control lines with significantly lower levels observed in R. solani infecting transgenic lines carrying the HD-RNAi constructs. This is the first report demonstrating the effectiveness of HD-RNAi against sheath blight and offers new opportunities for durable control of the disease as it does not rely on resistance conferred by major resistance genes.
Gene Targeting by Homology-Directed Repair in Rice Using a Geminivirus-Based CRISPR/Cas9 System
Publisher: Elsevier BV
Date: 07-2017
Heterotrimeric G proteins interact with defense-related receptor-like kinases in Arabidopsis
Publisher: Elsevier BV
Date: 09-2015
DOI: 10.1016/J.JPLPH.2015.09.005
Abstract: Heterotrimeric G proteins (G-proteins) are versatile signaling elements conserved in Eukaryotes. In animals G-proteins relay signals from 7-transmembrane spanning G protein-coupled receptors (GPCRs) to intracellular downstream effectors however, the existence of GPCRs in plants is controversial. Contrastingly, a surplus of receptor-like kinases (RLKs) provides signal recognition at the plant cell surface. It is established that G proteins are involved in plant defense and suggested that they relay signals from defense-related RLKs. However, it is unclear how the signaling is conducted, as physical interaction between the RLKs and G proteins has not been demonstrated. Using yeast split-ubiquitin system and Bimolecular Fluorescence Complementation assays, we demonstrate physical interaction between the Gα, Gγ1 and Gγ2 subunits, and the defense-related RD-type receptor like kinases CERK1, BAK1 and BIR1. At the same time, no interaction was detected with the non-RD RLK FLS2. We hypothesize that G-proteins mediate signal transduction immediately downstream of the pathogenesis-related RLKs.
Tomato and cotton G protein beta subunit mutants display constitutive autoimmune responses
Publisher: Wiley
Date: 11-2021
DOI: 10.1002/PLD3.359
Abstract: Heterotrimeric G protein Gβ‐deficient mutants in rice and maize display constitutive immune responses, whereas Arabidopsis Gβ mutants show impaired defense, suggesting the existence of functional differences between monocots and dicots. Using CRISPR/Cas9, we produced one hemizygous tomato line with a mutated SlGB1 Gβ gene. Homozygous slgb1 knockout mutants exhibit all the hallmarks of autoimmune mutants, including development of necrotic lesions, constitutive expression of defense‐related genes, and high endogenous levels of salicylic acid (SA) and reactive oxygen species, resulting in early seedling lethality. Virus‐induced silencing of Gβ in cotton reproduced the symptoms observed in tomato mutants, confirming that the autoimmune phenotype is not limited to monocot species but is also shared by dicots. Even though multiple genes involved in SA and ethylene signaling are highly induced by Gβ silencing in tomato and cotton, co‐silencing of SA or ethylene signaling components in cotton failed to suppress the lethal phenotype, whereas co‐silencing of the oxidative burst oxidase RbohD can repress lethality. Despite the autoimmune response observed in slgb1 mutants, we show that SlGB1 is a positive regulator of the pathogen‐associated molecular pattern (PAMP)‐triggered immunity (PTI) response in tomato. We speculate that the phenotypic differences observed between Arabidopsis and tomato/cotton/rice/maize Gβ knockouts do not necessarily reflect ergences in G protein‐mediated defense mechanisms.
Functional characterization of novel chitinase genes present in the sheath blight resistance QTL: Qsbr11-1 in rice line Tetep
Publisher: Frontiers Media SA
Date: 03-2016
A simple, robust and equipment-free DNA amplification readout in less than 30 seconds
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9RA04725E
Abstract: A simple and highly reliable DNA lification readout system for naked eye detection of lified DNA in under 30 seconds.
Genome Editing—Principles and Applications for Functional Genomics Research and Crop Improvement
Publisher: Informa UK Limited
Date: 04-07-2017
Simplified Assays for Evaluation of Resistance to Alternaria brassicicola and Turnip Mosaic Virus
Publisher: Springer New York
Date: 2016
DOI: 10.1007/978-1-4939-3115-6_18
Abstract: Studying the natural defense mechanisms developed by model plants such as Arabidopsis is an important approach towards the improvement of crop species. The availability of mutants as well as the relative easiness to silence any gene in Arabidopsis provides an invaluable source of genotypes that can be used to discover new elements involved in the defense response. Here we describe simple and reliable methods to evaluate susceptibility/resistance to the pathogenic fungus Alternaria brassicicola and the viral pathogen Turnip mosaic virus.
ISOLATION OF A CDNA CLONE FOR SPINACH LIPID TRANSFER PROTEIN AND EVIDENCE THAT THE PROTEIN IS SYNTHESIZED BY THE SECRETORY PATHWAY
Publisher: Oxford University Press (OUP)
Date: 1991
DOI: 10.1104/PP.95.1.164
The pineapple EST sequencing and microarray project
Publisher: International Society for Horticultural Science (ISHS)
Date: 02-2017
The pineapple AcMADS1 promoter confers high level expression in tomato and Arabidopsis flowering and fruiting tissues, but AcMADS1 does not complement the tomato LeMADS-RIN (rin) mutant
Publisher: Springer Science and Business Media LLC
Date: 20-08-2014
DOI: 10.1007/S11103-014-0236-3
Abstract: A previous EST study identified a MADS box transcription factor coding sequence, AcMADS1, that is strongly induced during non-climacteric pineapple fruit ripening. Phylogenetic analyses place the AcMADS1 protein in the same superclade as LeMADS-RIN, a master regulator of fruit ripening upstream of ethylene in climacteric tomato. LeMADS-RIN has been proposed to be a global ripening regulator shared among climacteric and non-climacteric species, although few functional homologs of LeMADS-RIN have been identified in non-climacteric species. AcMADS1 shares 67 % protein sequence similarity and a similar expression pattern in ripening fruits as LeMADS-RIN. However, in this study AcMADS1 was not able to complement the tomato rin mutant phenotype, indicating AcMADS1 may not be a functionally conserved homolog of LeMADS-RIN or has sufficiently erged to be unable to act in the context of the tomato network of interacting proteins. The AcMADS1 promoter directed strong expression of the GUS reporter gene to fruits and developing floral organs in tomato and Arabidopsis thaliana, suggesting AcMADS1 may play a role in flower development as well as fruitlet ripening. The AcMADS1 promoter provides a useful molecular tool for directing transgene expression, particularly where up-regulation in developing flowers and fruits is desirable.
New faces in plant innate immunity: Heterotrimeric G proteins
Publisher: Springer Science and Business Media LLC
Date: 07-08-2012
Optimization of CRISPR/Cas9 genome editing in cotton by improved sgRNA expression
Publisher: Springer Science and Business Media LLC
Date: 03-10-2018
Calcium-dependent protein kinase gene expression in response to physical and chemical stimuli in mungbean (Vigna radiata)
Publisher: Springer Science and Business Media LLC
Date: 03-1996
DOI: 10.1007/BF00019547
Abstract: A single-walled carbon nanotube/anatase (SWCNT/anatase) composite thin film with a transmittance of over 70% in the visible-light region was fabricated on a quartz glass substrate by heat treating a precursor film at 500 °C in air. The precursor film was formed by spin coating a mixed solution of the titania molecular precursor and well-dispersed SWCNTs (0.075 mass%) in ethanol. The anatase crystals and Ti
Delayed flowering in pineapples (Ananas comosus (L.) Merr.) caused by co-suppression of the ACACS2 gene
Publisher: International Society for Horticultural Science (ISHS)
Date: 2006
Differential expression of two calmodulin genes in response to physical and chemical stimuli
Publisher: Springer Science and Business Media LLC
Date: 03-1994
DOI: 10.1007/BF00029857
Insights into the molecular mechanisms of CRISPR/Cas9-mediated gene targeting at multiple loci in Arabidopsis
Publisher: Oxford University Press (OUP)
Date: 15-09-2022
Abstract: Homologous recombination-mediated gene targeting (GT) enables precise sequence knockin or sequence replacement, and thus is a powerful tool for heritable precision genome engineering. We recently established a clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeats-associated protein 9 (CRISPR/Cas9)-mediated approach for heritable GT in Arabidopsis (Arabidopsis thaliana), but its broad utility was not tested, and the underlying molecular mechanism was unclear. Here, we achieved precise GT at 14 out of 27 tested endogenous target loci using the sequential transformation approach and obtained vector-free GT plants by backcrossing. Thus, the sequential transformation GT method provides a broadly applicable technology for precise genome manipulation. We show that our approach generates heritable GT in the egg cell or early embryo of T1 Arabidopsis plants. Analysis of imprecise GT events suggested that single-stranded transfer DNA (T-DNA)/VirD2 complexes produced during the Agrobacterium (Agrobacterium tumefaciens) transformation process may serve as the donor templates for homologous recombination-mediated repair in the GT process. This study provides new insights into the molecular mechanisms of CRISPR/Cas9-mediated GT in Arabidopsis.
Expression analysis and subcellular localization of the Arabidopsis thaliana G-protein β-subunit AGB1
Publisher: Springer Science and Business Media LLC
Date: 10-05-2007
DOI: 10.1007/S00299-007-0356-1
Abstract: Heterotrimeric GTP-binding proteins (G-proteins), consisting of Galpha, Gbeta, and Ggamma subunits, function as molecular switches in many eukaryotic signal transduction pathways. In contrast to many eukaryotes, plants contain very few G-protein subunit isoforms that mediate a erse array of signalling functions. We investigated the contribution of cell type-specific expression and subcellular localization to this multifunctional signalling capacity for the Arabidopsis thaliana Gbeta subunit, AGB1. Analysis of AGB1 promoter::beta-glucuronidase (GUS) fusions in germinating seeds, seedlings, and flowering plants revealed that AGB1 is widely expressed throughout development in a complex manner. As well as demonstrating similarities to existing Arabidopsis G-protein subunit expression data, several features of the AGB1 expression pattern align closely with known or proposed G-protein functions. A C-terminal AGB1-green fluorescent protein (GFP) fusion was localized at the plasma membrane and in the nucleus of leaf epidermal cells, trichomes and root cells, supporting previous evidence that plant G-protein functionality relies on subcellular compartmentalization.
Characterisation of three ACC synthase gene family members during post-harvest-induced senescence in broccoli (Brassica oleracea L. var. italica)
Publisher: Springer Science and Business Media LLC
Date: 12-2003
DOI: 10.1007/BF03030368
A transient transformation system for gene characterization in upland cotton (Gossypium hirsutum)
Publisher: Springer Science and Business Media LLC
Date: 22-06-2018
Heterotrimeric G protein signalling in the plant kingdom
Publisher: The Royal Society
Date: 03-2013
DOI: 10.1098/RSOB.120186
Abstract: In animals, heterotrimeric G proteins, comprising α-, β-and γ-subunits, perceive extracellular stimuli through cell surface receptors, and transmit signals to ion channels, enzymes and other effector proteins to affect numerous cellular behaviours. In plants, G proteins have structural similarities to the corresponding molecules in animals but transmit signals by atypical mechanisms and effector proteins to control growth, cell proliferation, defence, stomate movements, channel regulation, sugar sensing and some hormonal responses. In this review, we summarize the current knowledge on the molecular regulation of plant G proteins, their effectors and the physiological functions studied mainly in two model organisms: Arabidopsis thaliana and rice ( Oryza sativa ). We also look at recent progress on structural analyses, systems biology and evolutionary studies.
Perspectives on the Application of Genome-Editing Technologies in Crop Breeding
Publisher: Elsevier BV
Date: 08-2019
DOI: 10.1016/J.MOLP.2019.06.009
Abstract: Most conventional and modern crop-improvement methods exploit natural or artificially induced genetic variations and require laborious characterization of the progenies of multiple generations derived from time-consuming genetic crosses. Genome-editing systems, in contrast, provide the means to rapidly modify genomes in a precise and predictable way, making it possible to introduce improvements directly into elite varieties. Here, we describe the range of applications available to agricultural researchers using existing genome-editing tools. In addition to providing ex les of genome-editing applications in crop breeding, we discuss the technical and social challenges faced by breeders using genome-editing tools for crop improvement.
G Proteins and Plant Innate Immunity
Publisher: Springer Berlin Heidelberg
Date: 16-10-2009
Fusarium oxysporum Infection Assays in Arabidopsis
Publisher: Humana Press
Date: 2013
DOI: 10.1007/978-1-62703-532-3_7
Abstract: Increased susceptibility to Fusarium oxysporum is one of the most conspicuous characteristics of the Arabidopsis mutants lacking the heterotrimeric G protein β and γ1 subunits. The molecular mechanisms placing these G proteins in the plant innate immunity network are yet to be discovered. However, a method to test susceptibility to and disease progression of an important plant pathogen, such as F. oxysporum, is of central importance to many plant defense studies. The optimized protocol presented here allows the routine processing and analysis of symptom progression in young Arabidopsis soil-grown seedlings and yields highly reproducible results.
Cloning and characterisation of a glutamate dehydrogenase cDNA from tomato (Lycopersicon esculentum L)
Publisher: Elsevier BV
Date: 02-1997
DOI: 10.1016/S0378-1119(96)00716-0
Abstract: A full-length cDNA (legdh1) has been cloned encoding glutamate dehydrogenase (GDH) from tomato (Lycopersicon esculentum L.). legdh1 is 1568 bp long and contains an open reading frame encoding a 44.8 kDa polypeptide with a putative mitochondrial-matrix-targeting pre-sequence at its N-terminus. Southern analysis indicates the existence of one copy of legdh1 per haploid genome, and no closely related genes were detected by Southern analysis at low stringency. We hypothesise that in tomato, the two GDH subunits may arise from post-transcriptional modifications of a single gene. Northern analysis reveals high expression of legdh1 in roots, lower levels of expression in stems, flowers and leaves, and no detectable expression in fruits. In general, there was no correlation between steady-state mRNA level and protein activity in the tissues analysed, again suggesting the importance of post-transcriptional events in the regulation of GDH. Comparison of cloned plant GDH proteins reveals a high degree of homology throughout the sequence except for a very specific, highly ergent region.
Heterotrimeric G proteins facilitate Arabidopsis resistance to necrotrophic pathogens and are involved in jasmonate signaling.
Publisher: Oxford University Press (OUP)
Date: 09-12-2005
Abstract: Heterotrimeric G proteinshave been previously linked to plant defense however a role for the Gβγ dimer in defense signaling has not been described to date. Using available Arabidopsis (Arabidopsis thaliana) mutants lacking functional Gα or Gβ subunits, we show that defense against the necrotrophic pathogens Alternaria brassicicola and Fusarium oxysporum is impaired in Gβ-deficient mutants while Gα-deficient mutants show slightly increased resistance compared to wild-type Columbia ecotype plants. In contrast, responses to virulent (DC3000) and avirulent (JL1065) strains of Pseudomonas syringae appear to be independent of heterotrimeric G proteins. The induction of a number of defense-related genes in Gβ-deficient mutants were severely reduced in response to A. brassicicola infection. In addition, Gβ-deficient mutants exhibit decreased sensitivity to a number of methyl jasmonate-induced responses such as induction of the plant defensin gene PDF1.2, inhibition of root elongation, seed germination, and growth of plants in sublethal concentrations of methyl jasmonate. In all cases, the behavior of the Gα-deficient mutants is coherent with the classic heterotrimeric mechanism of action, indicating that jasmonic acid signaling is influenced by the Gβγ functional subunit but not by Gα. We hypothesize that Gβγ acts as a direct or indirect enhancer of the jasmonate signaling pathway in plants.
Specific and Sensitive Isothermal Electrochemical Biosensor for Plant Pathogen DNA Detection with Colloidal Gold Nanoparticles as Probes
Publisher: Springer Science and Business Media LLC
Date: 17-01-2017
DOI: 10.1038/SREP38896
Abstract: Developing quick and sensitive molecular diagnostics for plant pathogen detection is challenging. Herein, a nanoparticle based electrochemical biosensor was developed for rapid and sensitive detection of plant pathogen DNA on disposable screen-printed carbon electrodes. This 60 min assay relied on the rapid isothermal lification of target pathogen DNA sequences by recombinase polymerase lification (RPA) followed by gold nanoparticle-based electrochemical assessment with differential pulse voltammetry (DPV). Our method was 10,000 times more sensitive than conventional polymerase chain reaction (PCR)/gel electrophoresis and could readily identify P. syringae infected plant s les even before the disease symptoms were visible. On the basis of the speed, sensitivity, simplicity and portability of the approach, we believe the method has potential as a rapid disease management solution for applications in agriculture diagnostics.
Saltational evolution of the heterotrimeric G protein signaling mechanisms in the plant kingdom
Publisher: American Association for the Advancement of Science (AAAS)
Date: 20-09-2016
DOI: 10.1126/SCISIGNAL.AAF9558
Abstract: Rapid ersification of the XLG family of Gα proteins may have enabled plants to adapt to the variable land environment.
Over-expression of a truncated Arabidopsis thaliana heterotrimeric G protein gamma subunit results in a phenotype similar to alpha and beta subunit knockouts
Publisher: Elsevier BV
Date: 05-2007
DOI: 10.1016/J.GENE.2007.02.008
Abstract: Heterotrimeric G proteins (G-proteins) are a erse class of signal transducing proteins which have been implicated in a variety of important roles in plants. When G-proteins are activated, they dissociate into two functional subunits (alpha and the betagamma dimer) that effectively relay the signal to a multitude of effectors. In animal systems, the betagamma dimer is anchored to the plasma membrane by a prenyl group present in the gamma subunit and membrane localization has proven vital for heterotrimer function. A semi-dominant negative strategy was designed aiming to disrupt heterotrimer function in Arabidopsis thaliana (ecotype Columbia) plants by over-expressing a truncated gamma subunit lacking the isoprenylation motif (gamma()). Northern analysis shows that the levels of expression of the mutant gamma subunit in several transgenic lines (35S-gamma()) are orders of magnitude higher than that of the native subunits. In-depth characterization of the 35S-gamma() lines has been carried out, specifically focusing on a number of developmental characteristics and responses to several stimuli previously shown to be affected in alpha- and beta-deficient mutants. In all cases, the transgenic lines expressing the mutant gamma subunit behave in the same way as the alpha- and/or the beta-deficient mutants, albeit with reduced severity of the phenotype. Our data indicates that signaling from both functional subunits, alpha and the beta/gamma dimer, is disrupted in the transgenic plants. Even though physical association of the subunits has been previously reported, our research provides evidence of the functional association of alpha and beta with the gamma subunits in Arabidopsis, while also suggesting that plasma membrane localization may be critical for function of plant heterotrimeric G proteins.
Immunocytolocalization of ferredoxin-GOGAT in the cells of green leaves and cotyledons of Lycopersicon esculentum
Publisher: Oxford University Press (OUP)
Date: 05-1988
DOI: 10.1104/PP.87.1.255
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