Proteomic analysis of nuclear proteins during dehydration of the resurrection plant Xerophyta viscosa (original) (raw)
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Proteomic analysis of leaf proteins during dehydration of the resurrection plant Xerophyta viscosa
Plant, Cell & Environment, 2007
The desiccation-tolerant phenotype of angiosperm resurrection plants is thought to rely on the induction of protective mechanisms that maintain cellular integrity during water loss. Two-dimensional (2D) sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of the Xerophyta viscosa Baker proteome was carried out during dehydration to identify proteins that may play a role in such mechanisms. Quantitative analysis revealed a greater number of changes in protein expression levels at 35% than at 65% relative water content (RWC) compared to fully hydrated plants, and 17 dehydrationresponsive proteins were identified by tandem mass spectrometry (MS). Proteins showing increased abundance during drying included an RNA-binding protein, chloroplast FtsH protease, glycolytic enzymes and antioxidants. A number of photosynthetic proteins declined sharply in abundance in X. viscosa at RWC below 65%, including four components of photosystem II (PSII), and Western blot analysis confirmed that two of these (psbP and Lhcb2) were not detectable at 30% RWC. These data confirm that poikilochlorophylly in X. viscosa involves the breakdown of photosynthetic proteins during dismantling of the thylakoid membranes. In contrast, levels of these photosynthetic proteins were largely maintained during dehydration in the homoiochlorophyllous species Craterostigma plantagineum Hochst, which does not dismantle thylakoid membranes on drying.
Main conclusion Provides a first comprehensive review of integrated physiological and molecular aspects of desiccation tolerance Xerophyta viscosa. A synopsis of biotechnological studies being undertaken to improve drought tolerance in maize is given. Xerophyta viscosa (Baker) is a monocotyledonous resurrection plant from the family Vellociacea that occurs in summer-rainfall areas of South Africa, Lesotho and Swaziland. It inhabits rocky terrain in exposed grasslands and frequently experiences periods of water deficit. Being a resurrection plant it tolerates the loss of 95 % of total cellular water, regaining full metabolic competency within 3 days of rehydration. In this paper, we review some of the molecular and physiological adaptations that occur during various stages of dehydration of X. viscosa, these being functionally grouped into early and late responses, which might be relevant to the attainment of desiccation tolerance. During early drying (to 55 % RWC) photosynthesis is shut down, there is increased presence and activity of housekeeping antioxidants and a redirection of metabolism to the increased formation of sucrose and raffinose family oligosaccharides. Other metabolic shifts suggest water replacement in vacuoles proposed to facilitate mechanical stabilization. Some regulatory processes observed include increased presence of a linker histone H1 variant, a Type 2C protein phosphatase, a calmodulin-and an ERD15-like protein. During the late stages of drying (to 10 % RWC) there was increased expression of several proteins involved in signal transduction, and retroelements speculated to be instrumental in gene silencing. There was induction of antioxidants not typically found in desiccation-sensitive systems, classical stress-associated proteins (HSP and LEAs), proteins involved in structural stabilization and those associated with changes in various metabolite pools during drying. Metabolites accumulated in this stage are proposed, inter alia, to facilitate subcellular stabilization by vitrification process which can include glass-and ionic liquid formation. Keywords Physiology Á Proteome Á Resurrection plant Á Transcriptome Á Vegetative desiccation tolerance Abbreviation ERD (LRD) Early (Late) response to desiccation
Plant Growth Regulation, 1998
Xerophyta humilis (Bak.) Dur. and Schinz is a poikilochlorophyllous resurrection plant in that it is tolerant of considerable water loss (< 5% relative water content [RWC]) and thylakoid membranes are dismantled and chlorophyll is lost during dehydration. In this paper we examined the processes associated with recovery from desiccation upon rehydration. Dried leaf explants were rehydrated in water (control) or in solutions of actinomycin-D or cyclohexamide in order to determine to what extent initial recovery was dependant on de novo transcription and translation respectively. Our results suggest that considerable protection of subcellular organisation and components of metabolism occurs during drying such that the initial recovery of metabolism on rehydration is virtually independent of de novo transcription of nuclear genes. However recovery does require the synthesis of new proteins. The plasmalemma remains intact and macromolecular synthesis is not required for maintenance of its integrity. Messenger RNA's for chlorophyll biosynthesis appear to be stored in a stable form in the dried leaves and are translated on rehydration. Similarly most of the mRNA's necessary for recovery of electron transport in the chloroplast (as determined by measuring the quantum efficiency of photosystem II [F V /F M ] using chlorophyll fluorescence) appear to be stabily present in the dried leaves. However, for total recovery of F V /F M new genomic transcription is necessary.
Physiologia Plantarum, 2004
Xerophyta humilis (Bak.) Dur and Schinz is an indigenous Southern African resurrection plant which is able to protect itself from the stresses associated with extreme dehydration. For the purpose of analysing global patterns of gene expression in response to desiccation and recovery on rehydration, we have generated a normalized 10 900 library, representing genes from root and leaf tissue that are expressed during the dehydration-rehydration cycle. For the small-scale microarray analysis described here, 424 cDNAs were sequenced, annotated, arrayed and hybridized with hydrated and dehydrated, leaf-specific RNA. Reverse Northern blots were used as an alternative method to compare the expression results. A total of 55 dehydration-inducible cDNAs were identified combining the results of both methods. Northern blot analysis of 14 of the 55 the dehydration-upregulated cDNAs verified the expression status of all 14 genes. Dehydration-upregulated cDNAs included those homologous to known dehydration stress-responsive genes encoding metallothioneins, galactinol synthases, an aldose reductase and a glyoxalase. A large number of genes encoding late embryonic abundant proteins (LEAs), dehydrins and desiccation-related proteins were also identified, suggesting that proteins that provide mechanical and antioxidant protection against water loss dominate the mRNA population in desiccated X. humilis leaf tissue. Dehydration-upregulated genes identified in this study, and not previously implicated in the dehydration response, include cDNAs encoding a putative chloroplast RNA-binding protein and a protein containing SNF2/helicase domains. Comparisons with microarray data, which profile the dehydration response in desiccation-sensitive plants, reveal differences in expression patterns between X. humilis and Arabidopsis and rice that could provide clues as to the mechanisms underlying desiccation-tolerant and -sensitive phenotypes. The X. humilis library promises to be a useful resource for transcript profiling the dehydration and rehydration response in a desiccationtolerant plant.
Label-free proteomic analysis of Xerophyta schlechteri leaf tissue under dehydration stress
IAA-Asp-Indole-3-acetic acid IBA-Indole-3-butyric acid ICA-Indole-3-carboxylic acid ICAT-Isotope-coded affinity tags iTRAQ-Isobaric tags for relative and absolute quantification JA-Jasmonic acid x JA lle-Jasmonyl-l-isoleucine KEGG-Kyoto Encyclopaedia of Genes and Genomes LC-MS-Liquid chromatography-mass spectrometry LEA-Late embryogenesis abundant protein LFQ-Label-free quantification LRD-Late response to drying MMTS-Methylmethanethiosulphonate MRD-Mid response to drying MSTFA-N-Methyl-N-(trimethylsilyl) trifluoroacetamide PAI-Protein abundance index RFO-Raffinose family oligosaccharides RNS-Reactive nitrogen species ROS-Reactive oxygen species RWC-Relative water content SA-Salicylic acid SD-Standard deviation SDS-Sodium dodecyl sulfate
Planta, 2018
Main conclusion Multiple dehydration/rehydration treatments improve the adaptation of Craterostigma plantagineum to desiccation by accumulating stress-inducible transcripts, proteins and metabolites. These molecules serve as stress imprints or memory and can lead to increased stress tolerance. It has been reported that repeated exposure to dehydration may generate stronger reactions during a subsequent dehydration treatment in plants. This stimulated us to address the question whether the desiccation tolerant resurrection plant Craterostigma plantagineum has a stress memory. The expression of four representative stress-related genes gradually increased during four repeated dehydration/rehydration treatments in C. plantagineum. These genes reflect a transcriptional memory and are trainable genes. In contrast, abundance of chlorophyll synthesis/degradation-related transcripts did not change during dehydration and remained at a similar level as in the untreated tissues during the recovery phase. During the four dehydration/rehydration treatments the level of ROS pathway-related transcripts, superoxide dismutase (SOD) activity, proline, and sucrose increased, whereas H 2 O 2 content and electrolyte leakage decreased. Malondialdehyde (MDA) content did not change during the dehydration, which indicates a gain of stress tolerance. At the protein level, increased expression of four representative stress-related proteins showed that the activated stress memory can persist over several days. The phenomenon described here could be a general feature of dehydration stress memory responses in resurrection plants.
TOWARDS PROTEOMICS OF DESICCATION TOLERANCE IN THE RESURRECTION PLANT HABERLEA RHODOPENSIS
Comptes rendus de l'Académie bulgare des sciences: sciences mathématiques et naturelles
Drought is a major environmental constraint of agricultural productivity worldwide. Understanding the molecular basis of drought tolerance in plants is of importance with respect to basic research and for its improvement in crop plants. Resurrection plants are a small group of angiosperms that can survive extreme dehydration to the point of desiccation and are excellent model systems to investigate the mechanisms of desiccation tolerance. We have chosen to study the leaf proteome response to desiccation of the extremely desiccation-tolerant plant Haberlea rhodopensis. We used high-resolution denaturing two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) to compare the proteomes of hydrated control plants to those dehydrated to 16% water content. As a result we were able to separate and quantify a total of 152 and 148 protein spots in control and fully dry plants, respectively. Comparative analysis indicated differences in protein expression profiles between control and trea...
2001
Xerophyta viscosa (Baker) is a monocotyledonous resurrection plant that is capable of tolerating extremes of desiccation. Upon rewatering, it rehydrates completely, assuming its full physiological activities. Studies on changes in gene expression associated with dehydration stress tolerance were conducted. A cDNA library was constructed from mRNA isolated from dehydrated X. viscosa leaves [85%, 37% and 5% relative water content (RWC)]. XVT8 represents one of 30 randomly selected clones that were differentially expressed when X. viscosa was dehydrated. Sequence analysis of XVT8 revealed that XVT8 exhibited 45% and 43% identity to dehydrin proteins from Arabidopsis thaliana and Pisum sativum respectively, at the amino acid level. XVT8 encodes a glycine-rich protein (27 kDa) which is largely hydrophilic and contains a hydrophobic segment at the C-terminus. Southern blot analysis confirmed the presence of XVT8 in the X. viscosa genome. XVT8 transcripts accumulated in X. viscosa plants that were exposed to heat, low temperature and dehydration stresses, and to exogenous abscisic acid and ethylene. These results provide direct evidence for the heat, low temperature, dehydration, abscisic acid and ethylene-dependent regulation of the XVT8 gene in X. viscosa.
Phytochemistry, 2011
Drought and its affects on agricultural production is a serious issue facing global efforts to increase food supplies and ensure food security for the growing world population. Understanding how plants respond to dehydration is an important prerequisite for developing strategies for crop improvement in drought tolerance. This has proved to be a difficult task as all of the current research plant models do not tolerate cellular dehydration well and, like all crops, they succumb to the effects of a relatively small water deficit of À4 MPa or less. For these reasons many researchers have started to investigate the usefulness of resurrection plants, plants that can survive extremes of dehydration to the point of desiccation, to provide answers as to how plants tolerate water loss. We have chosen to investigate the leaf proteome response of the desiccation-tolerant grass Sporobolus stapfianus Gandoger to dehydration to a water content that encompasses the initiation of the cellular protection response evident in these plants. We used a combination of two-dimensional Difference Gel Electrophoresis (2D-DIGE) and liquid chromatography-tandem-mass spectrometry to compare the proteomes of young leaves from hydrated plants to those dehydrated to approximately 30% relative water content. High-resolution 2D-DIGE revealed 96 significantly different proteins and 82 of these spots yielded high-quality protein assignments by tandem-mass spectrometry. Inferences from the bioinformatic annotations of these proteins revealed the possible involvement of protein kinase-based signaling cascades and brassinosteroid involvement in the regulation of the cellular protection response. Enzymes of glycolysis, both cytoplasmic and plastidic, as well as five enzymes of the Calvin cycle increased in abundance. However, the RuBisCO large subunit and associated proteins were reduced, indicating a loss of carbon fixation but a continued need to supply the necessary carbon skeletons for the constituents involved in cell protection. Changes in abundance of several proteins that appear to have a function in chromatin structure and function indicate that these structures undergo significant changes as a result of dehydration. These observations give a unique ''snap-shot'' of the proteome of S. stapfianus at a critical point in the passage towards desiccation.