Base de dados : MEDLINE
Pesquisa : B01.650.940.800.575.912.250.583.300 [Categoria DeCS]
Referências encontradas : 52 [refinar]
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[PMID]:28131342
[Au] Autor:Juszczak I; Bartels D
[Ad] Endereço:Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, Kirschallee 1, D-53115 Bonn, Germany.
[Ti] Título:LEA gene expression, RNA stability and pigment accumulation in three closely related Linderniaceae species differing in desiccation tolerance.
[So] Source:Plant Sci;255:59-71, 2017 Feb.
[Is] ISSN:1873-2259
[Cp] País de publicação:Ireland
[La] Idioma:eng
[Ab] Resumo:Desiccation-tolerant plants (Craterostigma plantagineum and Lindernia brevidens) evolved a highly efficient strategies to prevent dehydration-induced irreversible damage. The protection system involves synthesis of LEA proteins, decrease of photosynthetic activity and activation of antioxidant systems. The regulation of these processes requires joint action of multiple proteins. Here, we present comparative analyses of accumulation of transcripts encoding components of the protection machinery, such as selected LEA proteins, enzymes of the chlorophyll degradation pathway and anthocyanin biosynthesis enzymes in total and polysomal RNA pools. The analyses revealed that desiccation-tolerant plants recruit mRNAs to ribosomes with higher efficiency than the desiccation-sensitive species L. subracemosa. Desiccation-tolerant species accumulated high amounts of LEA transcripts during dehydration and precisely controlled the amounts of chlorophyll keeping it at a level sufficient to activate photosynthesis after rehydration. In contrast, mRNA of L. subracemosa was prone to dehydration-induced degradation, decomposition of the photosynthetic apparatus and degradation of free chlorophyll. Thus, the results of the studies point to differences in the control of gene expression and degradation of chlorophyll in desiccation-tolerant versus desiccation-sensitive species when the plants were subjected to dehydration.
[Mh] Termos MeSH primário: Adaptação Fisiológica
Clorofila/metabolismo
Secas
Magnoliopsida/genética
Proteínas de Plantas/genética
Estabilidade de RNA
Água/metabolismo
[Mh] Termos MeSH secundário: Antocianinas/metabolismo
Craterostigma/genética
Craterostigma/metabolismo
Desidratação
Regulação da Expressão Gênica de Plantas
Fenômenos Genéticos
Magnoliopsida/metabolismo
Fotossíntese
Pigmentos Biológicos/metabolismo
Proteínas de Plantas/metabolismo
RNA Mensageiro/metabolismo
RNA de Plantas/metabolismo
Especificidade da Espécie
Estresse Fisiológico
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anthocyanins); 0 (Pigments, Biological); 0 (Plant Proteins); 0 (RNA, Messenger); 0 (RNA, Plant); 0 (late embryogenesis abundant protein, plant); 059QF0KO0R (Water); 1406-65-1 (Chlorophyll)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170130
[St] Status:MEDLINE


  2 / 52 MEDLINE  
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[PMID]:27258321
[Au] Autor:Zia A; Walker BJ; Oung HM; Charuvi D; Jahns P; Cousins AB; Farrant JM; Reich Z; Kirchhoff H
[Ad] Endereço:Institute of Biological Chemistry, Washington State University, Pullman, WA, 99164-6340, USA.
[Ti] Título:Protection of the photosynthetic apparatus against dehydration stress in the resurrection plant Craterostigma pumilum.
[So] Source:Plant J;87(6):664-80, 2016 Sep.
[Is] ISSN:1365-313X
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The group of homoiochlorophyllous resurrection plants evolved the unique capability to survive severe drought stress without dismantling the photosynthetic machinery. This implies that they developed efficient strategies to protect the leaves from reactive oxygen species (ROS) generated by photosynthetic side reactions. These strategies, however, are poorly understood. Here, we performed a detailed study of the photosynthetic machinery in the homoiochlorophyllous resurrection plant Craterostigma pumilum during dehydration and upon recovery from desiccation. During dehydration and rehydration, C. pumilum deactivates and activates partial components of the photosynthetic machinery in a specific order, allowing for coordinated shutdown and subsequent reinstatement of photosynthesis. Early responses to dehydration are the closure of stomata and activation of electron transfer to oxygen accompanied by inactivation of the cytochrome b6 f complex leading to attenuation of the photosynthetic linear electron flux (LEF). The decline in LEF is paralleled by a gradual increase in cyclic electron transport to maintain ATP production. At low water contents, inactivation and supramolecular reorganization of photosystem II becomes apparent, accompanied by functional detachment of light-harvesting complexes and interrupted access to plastoquinone. This well-ordered sequence of alterations in the photosynthetic thylakoid membranes helps prepare the plant for the desiccated state and minimize ROS production.
[Mh] Termos MeSH primário: Craterostigma/fisiologia
Fotossíntese/fisiologia
[Mh] Termos MeSH secundário: Dióxido de Carbono/metabolismo
Complexo Citocromos b6f/metabolismo
Desidratação
Transporte de Elétrons
Complexo de Proteína do Fotossistema II/metabolismo
Estômatos de Plantas/fisiologia
Tilacoides/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Photosystem II Protein Complex); 142M471B3J (Carbon Dioxide); 9035-40-9 (Cytochrome b6f Complex)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171011
[Lr] Data última revisão:
171011
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160604
[St] Status:MEDLINE
[do] DOI:10.1111/tpj.13227


  3 / 52 MEDLINE  
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[PMID]:26687373
[Au] Autor:Guajardo E; Correa JA; Contreras-Porcia L
[Ad] Endereço:Departamento de Ecología y Biodiversidad, Facultad de Ecología y Recursos Naturales, Universidad Andres Bello, República 440, Santiago, Chile.
[Ti] Título:Role of abscisic acid (ABA) in activating antioxidant tolerance responses to desiccation stress in intertidal seaweed species.
[So] Source:Planta;243(3):767-81, 2016 Mar.
[Is] ISSN:1432-2048
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:MAIN CONCLUSION: The hormone ABA regulates the oxidative stress state under desiccation in seaweed species; an environmental condition generated during daily tidal changes. Desiccation is one of the most important factors that determine the distribution pattern of intertidal seaweeds. Among most tolerant seaweed is Pyropia orbicularis, which colonizes upper intertidal zones along the Chilean coast. P. orbicularis employs diverse mechanisms of desiccation tolerance (DT) (among others, e.g., antioxidant activation, photoinhibition, and osmo-compatible solute overproduction) such as those used by resurrection plants and bryophytes. In these organisms, the hormone abscisic acid (ABA) plays an important role in regulating responses to water deficit, including gene expression and the activity of antioxidant enzymes. The present study determined the effect of ABA on the activation of antioxidant responses during desiccation in P. orbicularis and in the sensitive species Mazzaella laminarioides and Lessonia spicata. Changes in endogenous free and conjugated ABA, water content during the hydration-desiccation cycle, enzymatic antioxidant activities [ascorbate peroxidase (AP), catalase (CAT) and peroxiredoxine (PRX)], and levels of lipid peroxidation and cell viability were evaluated. The results showed that P. orbicularis had free ABA levels 4-7 times higher than sensitive species, which was overproduced during water deficit. Using two ABA inhibitors (sodium tungstate and ancymidol), ABA was found to regulate the activation of the antioxidant enzymes activities during desiccation. In individuals exposed to exogenous ABA the enzyme activity increased, concomitant with low lipid peroxidation and high cell viability. These results demonstrate the participation of ABA in the regulation of DT in seaweeds, and suggest that regulatory mechanisms with ABA signaling could be of great importance for the adaptation of these organisms to dehydration.
[Mh] Termos MeSH primário: Ácido Abscísico/metabolismo
Proteínas de Algas/metabolismo
Craterostigma/fisiologia
Reguladores de Crescimento de Planta/metabolismo
Rodófitas/fisiologia
[Mh] Termos MeSH secundário: Adaptação Fisiológica
Antioxidantes/metabolismo
Ascorbato Peroxidases/metabolismo
Catalase/metabolismo
Craterostigma/citologia
Dessecação
Peroxidação de Lipídeos
Estresse Oxidativo/efeitos dos fármacos
Rodófitas/citologia
Estresse Fisiológico
Superóxido Dismutase/metabolismo
Água/fisiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Algal Proteins); 0 (Antioxidants); 0 (Plant Growth Regulators); 059QF0KO0R (Water); 72S9A8J5GW (Abscisic Acid); EC 1.11.1.11 (Ascorbate Peroxidases); EC 1.11.1.6 (Catalase); EC 1.15.1.1 (Superoxide Dismutase)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:171005
[Lr] Data última revisão:
171005
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151222
[St] Status:MEDLINE
[do] DOI:10.1007/s00425-015-2438-6


  4 / 52 MEDLINE  
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[PMID]:26607676
[Au] Autor:Giarola V; Krey S; von den Driesch B; Bartels D
[Ad] Endereço:Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Kirschallee 1, Bonn, D-53115, Germany.
[Ti] Título:The Craterostigma plantagineum glycine-rich protein CpGRP1 interacts with a cell wall-associated protein kinase 1 (CpWAK1) and accumulates in leaf cell walls during dehydration.
[So] Source:New Phytol;210(2):535-50, 2016 Apr.
[Is] ISSN:1469-8137
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Craterostigma plantagineum tolerates extreme desiccation. Leaves of this plant shrink and extensively fold during dehydration and expand again during rehydration, preserving their structural integrity. Genes were analysed that may participate in the reversible folding mechanism. Analysis of transcripts abundantly expressed in desiccated leaves identified a gene putatively coding for an apoplastic glycine-rich protein (CpGRP1). We studied the expression, regulation and subcellular localization of CpGRP1 and its ability to interact with a cell wall-associated protein kinase (CpWAK1) to understand the role of CpGRP1 in the cell wall during dehydration. The CpGRP1 protein accumulates in the apoplast of desiccated leaves. Analysis of the promoter revealed that the gene expression is mainly regulated at the transcriptional level, is independent of abscisic acid (ABA) and involves a drought-responsive cis-element (DRE). CpGRP1 interacts with CpWAK1 which is down-regulated in response to dehydration. Our data suggest a role of the CpGRP1-CpWAK1 complex in dehydration-induced morphological changes in the cell wall during dehydration in C. plantagineum. Cell wall pectins and dehydration-induced pectin modifications are predicted to be involved in the activity of the CpGRP1-CpWAK1 complex.
[Mh] Termos MeSH primário: Parede Celular/metabolismo
Craterostigma/metabolismo
Glicina/metabolismo
Folhas de Planta/metabolismo
Proteínas de Plantas/metabolismo
Proteínas Quinases/metabolismo
[Mh] Termos MeSH secundário: Ácido Abscísico/farmacologia
Sequência de Aminoácidos
Proteínas de Arabidopsis/metabolismo
Sequência de Bases
Parede Celular/efeitos dos fármacos
Craterostigma/efeitos dos fármacos
Craterostigma/genética
DNA Complementar/genética
DNA Complementar/isolamento & purificação
Desidratação
Regulação para Baixo/efeitos dos fármacos
Secas
Eletroforese em Gel Bidimensional
Regulação da Expressão Gênica de Plantas/efeitos dos fármacos
Proteínas de Fluorescência Verde/metabolismo
Modelos Biológicos
Folhas de Planta/efeitos dos fármacos
Proteínas de Plantas/química
Proteínas de Plantas/genética
Regiões Promotoras Genéticas/genética
Ligação Proteica/efeitos dos fármacos
Proteínas Recombinantes de Fusão/metabolismo
Saccharomyces cerevisiae/metabolismo
Análise de Sequência de DNA
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Arabidopsis Proteins); 0 (DNA, Complementary); 0 (Plant Proteins); 0 (Recombinant Fusion Proteins); 147336-22-9 (Green Fluorescent Proteins); 72S9A8J5GW (Abscisic Acid); EC 2.7.- (Protein Kinases); TE7660XO1C (Glycine)
[Em] Mês de entrada:1612
[Cu] Atualização por classe:161230
[Lr] Data última revisão:
161230
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151127
[St] Status:MEDLINE
[do] DOI:10.1111/nph.13766


  5 / 52 MEDLINE  
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[PMID]:26376004
[Au] Autor:Challabathula D; Puthur JT; Bartels D
[Ad] Endereço:Department of Life Sciences, School of Basic and Applied Sciences, Central University of Tamil Nadu, Tamil Nadu, India.
[Ti] Título:Surviving metabolic arrest: photosynthesis during desiccation and rehydration in resurrection plants.
[So] Source:Ann N Y Acad Sci;1365(1):89-99, 2016 Feb.
[Is] ISSN:1749-6632
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Photosynthesis is the key process that is affected by dehydration in plants. Desiccation-tolerant resurrection plants can survive conditions of very low relative water content. During desiccation, photosynthesis is not operational, but is recovered within a short period after rehydration. While homoiochlorophyllous resurrection plants retain their photosynthetic apparatus during desiccation, poikilochlorophyllous resurrection species dismantle chloroplasts and degrade chlorophyll but resynthesize them again during rehydration. Dismantling the chloroplasts avoids the photooxidative stress in poikilochlorophyllous resurrection plants, whereas it is minimized in homoiochlorophyllous plants through the synthesis of antioxidant enzymes and protective proteins or metabolites. Although the cellular protection mechanisms in both of these species vary, these mechanisms protect cells from desiccation-induced damage and restore photosynthesis upon rehydration. Several of the proteins synthesized during dehydration are localized in chloroplasts and are believed to play major roles in the protection of photosynthetic structures and in recovery in resurrection species. This review focuses on the strategies of resurrection plants in terms of how they protect their photosynthetic apparatus from oxidative stress during desiccation without membrane damage and with full recovery during rehydration. We review the role of the dehydration-induced protection mechanisms in chloroplasts and how photosynthesis is restored during rehydration.
[Mh] Termos MeSH primário: Adaptação Fisiológica/fisiologia
Craterostigma/metabolismo
Fotossíntese/fisiologia
Folhas de Planta/metabolismo
[Mh] Termos MeSH secundário: Cloroplastos/metabolismo
Dessecação
Água/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; REVIEW
[Nm] Nome de substância:
059QF0KO0R (Water)
[Em] Mês de entrada:1608
[Cu] Atualização por classe:160403
[Lr] Data última revisão:
160403
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150917
[St] Status:MEDLINE
[do] DOI:10.1111/nyas.12884


  6 / 52 MEDLINE  
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[PMID]:26633550
[Au] Autor:Williams B; Njaci I; Moghaddam L; Long H; Dickman MB; Zhang X; Mundree S
[Ad] Endereço:Centre for Tropical Crops and Biocommodities, Queensland University of Technology, Brisbane, Queensland, Australia.
[Ti] Título:Trehalose Accumulation Triggers Autophagy during Plant Desiccation.
[So] Source:PLoS Genet;11(12):e1005705, 2015 Dec.
[Is] ISSN:1553-7404
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Global climate change, increasingly erratic weather and a burgeoning global population are significant threats to the sustainability of future crop production. There is an urgent need for the development of robust measures that enable crops to withstand the uncertainty of climate change whilst still producing maximum yields. Resurrection plants possess the unique ability to withstand desiccation for prolonged periods, can be restored upon watering and represent great potential for the development of stress tolerant crops. Here, we describe the remarkable stress characteristics of Tripogon loliiformis, an uncharacterised resurrection grass and close relative of the economically important cereals, rice, sorghum, and maize. We show that T. loliiformis survives extreme environmental stress by implementing autophagy to prevent Programmed Cell Death. Notably, we identified a novel role for trehalose in the regulation of autophagy in T.loliiformis. Transcriptome, Gas Chromatography Mass Spectrometry, immunoblotting and confocal microscopy analyses directly linked the accumulation of trehalose with the onset of autophagy in dehydrating and desiccated T. loliiformis shoots. These results were supported in vitro with the observation of autophagosomes in trehalose treated T. loliiformis leaves; autophagosomes were not detected in untreated samples. Presumably, once induced, autophagy promotes desiccation tolerance in T.loliiformis, by removal of cellular toxins to suppress programmed cell death and the recycling of nutrients to delay the onset of senescence. These findings illustrate how resurrection plants manipulate sugar metabolism to promote desiccation tolerance and may provide candidate genes that are potentially useful for the development of stress tolerant crops.
[Mh] Termos MeSH primário: Autofagia/genética
Craterostigma/crescimento & desenvolvimento
Transcriptoma/genética
Trealose/metabolismo
[Mh] Termos MeSH secundário: Mudança Climática
Craterostigma/genética
Dessecação
Oryza
Folhas de Planta/genética
Folhas de Planta/metabolismo
Poaceae/genética
Estresse Fisiológico/genética
Trealose/genética
Água
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
059QF0KO0R (Water); B8WCK70T7I (Trehalose)
[Em] Mês de entrada:1606
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151204
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pgen.1005705


  7 / 52 MEDLINE  
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[PMID]:26025524
[Au] Autor:Giarola V; Challabathula D; Bartels D
[Ad] Endereço:Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, Kirschallee 1, D-53115 Bonn, Germany.
[Ti] Título:Quantification of expression of dehydrin isoforms in the desiccation tolerant plant Craterostigma plantagineum using specifically designed reference genes.
[So] Source:Plant Sci;236:103-15, 2015 Jul.
[Is] ISSN:1873-2259
[Cp] País de publicação:Ireland
[La] Idioma:eng
[Ab] Resumo:Craterostigma plantagineum is a desiccation tolerant resurrection plant. Many genes are induced during desiccation. Dehydrins are a group of dehydration-induced genes present in all higher plants. The current study aims at classifying the most abundantly expressed dehydrin genes from vegetative tissues of C. plantagineum and quantifying their expression. To identify variations between dehydrin isoforms at different stages of desiccation and rehydration by RT-qPCR, the target mRNA requires an accurate and reliable normalization. Previously we reported that RNAs from leaves and roots of C. plantagineum are not degraded during desiccation and subsequent rehydration thus allowing the use of RT-qPCR to test the stability of reference genes. The expression stability of eight candidate reference genes was tested in leaves, roots and callus. These genes were ranked according to their stability of gene expression using GeNorm(PLUS) and RefFinder. The most consistently expressed reference genes in each tissue were identified and used to normalize gene expression data. Dehydrin isoforms were divided in three groups based on the expression level during the desiccation process in three different tissues (leaves, roots and callus).
[Mh] Termos MeSH primário: Craterostigma/genética
Regulação da Expressão Gênica de Plantas
Proteínas de Plantas/genética
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Craterostigma/metabolismo
Dados de Sequência Molecular
Folhas de Planta/metabolismo
Proteínas de Plantas/metabolismo
Raízes de Plantas/metabolismo
Isoformas de Proteínas/genética
Isoformas de Proteínas/metabolismo
Alinhamento de Sequência
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Plant Proteins); 0 (Protein Isoforms); 134711-03-8 (dehydrin proteins, plant)
[Em] Mês de entrada:1603
[Cu] Atualização por classe:150530
[Lr] Data última revisão:
150530
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150531
[St] Status:MEDLINE


  8 / 52 MEDLINE  
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[PMID]:26002527
[Au] Autor:Giarola V; Bartels D
[Ad] Endereço:Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Kirschallee 1, 53115, Bonn, Germany.
[Ti] Título:What can we learn from the transcriptome of the resurrection plant Craterostigma plantagineum?
[So] Source:Planta;242(2):427-34, 2015 Aug.
[Is] ISSN:1432-2048
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:MAIN CONCLUSION: The desiccation transcriptome of the resurrection plant C. plantagineum is composed of conserved protein coding transcripts, taxonomically restricted transcripts and recently evolved non-protein coding transcripts. Research in resurrection plants has been hampered by the lack of genome sequence information, but recently introduced sequencing technologies overcome this limitation partially and provide access to the transcriptome of these plants. Transcriptome studies showed that mechanisms involved in desiccation tolerance are conserved in resurrection plants, seeds and pollen. The accumulation of protective molecules such as sugars and LEA proteins are major components in desiccation tolerance. Leaf folding, chloroplast protection and protection during rehydration must involve specific molecular mechanisms, but the basis of such mechanisms is mainly unknown. The study of regulatory regions of a desiccation-induced C. plantagineum gene suggests that cis-regulatory elements may be responsible for expression variations in desiccation tolerant and non-desiccation-tolerant plants. The analysis of the C. plantagineum transcriptome also revealed that part of it is composed of taxonomically restricted genes (TRGs) and non-protein coding RNAs (ncRNAs). TRGs are known to code for new traits required for the adaptation of organisms to particular environmental conditions. Thus the study of TRGs from resurrection plants should reveal species-specific functions related to the desiccation tolerance phenotype. Non-protein coding RNAs can regulate gene expression at epigenetic, transcriptional and post-transcriptional level and thus these RNAs may be key players in the rewiring of regulatory networks of desiccation-related genes in C. plantagineum.
[Mh] Termos MeSH primário: Craterostigma/genética
Transcriptoma/genética
[Mh] Termos MeSH secundário: Adaptação Fisiológica/genética
Craterostigma/fisiologia
Dessecação
Regulação da Expressão Gênica de Plantas
Especificidade da Espécie
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Em] Mês de entrada:1604
[Cu] Atualização por classe:171005
[Lr] Data última revisão:
171005
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150524
[St] Status:MEDLINE
[do] DOI:10.1007/s00425-015-2327-z


  9 / 52 MEDLINE  
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[PMID]:25998524
[Au] Autor:Farrant JM; Cooper K; Hilgart A; Abdalla KO; Bentley J; Thomson JA; Dace HJ; Peton N; Mundree SG; Rafudeen MS
[Ad] Endereço:Department of Molecular and Cell Biology, University of Cape Town, Private Bag X3, Rondebosch, 7701, South Africa, jill.farrant@uct.ac.za.
[Ti] Título:A molecular physiological review of vegetative desiccation tolerance in the resurrection plant Xerophyta viscosa (Baker).
[So] Source:Planta;242(2):407-26, 2015 Aug.
[Is] ISSN:1432-2048
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo: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.
[Mh] Termos MeSH primário: Adaptação Fisiológica
Craterostigma/fisiologia
Dessecação
[Mh] Termos MeSH secundário: Biotecnologia
Craterostigma/anatomia & histologia
Craterostigma/classificação
Craterostigma/genética
Estresse Oxidativo
Estresse Fisiológico
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; REVIEW
[Em] Mês de entrada:1604
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150523
[St] Status:MEDLINE
[do] DOI:10.1007/s00425-015-2320-6


  10 / 52 MEDLINE  
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[PMID]:25713340
[Au] Autor:Charuvi D; Nevo R; Shimoni E; Naveh L; Zia A; Adam Z; Farrant JM; Kirchhoff H; Reich Z
[Ad] Endereço:Department of Biological Chemistry (D.C., R.N., Z.R.) and Electron Microscopy Unit (E.S.), Weizmann Institute of Science, Rehovot 76100, Israel;Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, Hebrew University of Jerusalem, Rehovot 76100, Israel (L.N., Z.A.);Institute of Bio
[Ti] Título:Photoprotection conferred by changes in photosynthetic protein levels and organization during dehydration of a homoiochlorophyllous resurrection plant.
[So] Source:Plant Physiol;167(4):1554-65, 2015 Apr.
[Is] ISSN:1532-2548
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:During desiccation, homoiochlorophyllous resurrection plants retain most of their photosynthetic apparatus, allowing them to resume photosynthetic activity quickly upon water availability. These plants rely on various mechanisms to prevent the formation of reactive oxygen species and/or protect their tissues from the damage they inflict. In this work, we addressed the issue of how homoiochlorophyllous resurrection plants deal with the problem of excessive excitation/electron pressures during dehydration using Craterostigma pumilum as a model plant. To investigate the alterations in the supramolecular organization of photosynthetic protein complexes, we examined cryoimmobilized, freeze-fractured leaf tissues using (cryo)scanning electron microscopy. These examinations revealed rearrangements of photosystem II (PSII) complexes, including a lowered density during moderate dehydration, consistent with a lower level of PSII proteins, as shown by biochemical analyses. The latter also showed a considerable decrease in the level of cytochrome f early during dehydration, suggesting that initial regulation of the inhibition of electron transport is achieved via the cytochrome b6f complex. Upon further dehydration, PSII complexes are observed to arrange into rows and semicrystalline arrays, which correlates with the significant accumulation of sucrose and the appearance of inverted hexagonal lipid phases within the membranes. As opposed to PSII and cytochrome f, the light-harvesting antenna complexes of PSII remain stable throughout the course of dehydration. Altogether, these results, along with photosynthetic activity measurements, suggest that the protection of retained photosynthetic components is achieved, at least in part, via the structural rearrangements of PSII and (likely) light-harvesting antenna complexes into a photochemically quenched state.
[Mh] Termos MeSH primário: Craterostigma/fisiologia
Fotossíntese/fisiologia
Complexo de Proteínas do Centro de Reação Fotossintética/metabolismo
Complexo de Proteína do Fotossistema II/metabolismo
[Mh] Termos MeSH secundário: Craterostigma/genética
Craterostigma/efeitos da radiação
Complexo Citocromos b6f/genética
Complexo Citocromos b6f/metabolismo
Desidratação
Dessecação
Transporte de Elétrons
Luz
Complexo de Proteínas do Centro de Reação Fotossintética/genética
Folhas de Planta/genética
Folhas de Planta/fisiologia
Folhas de Planta/efeitos da radiação
Proteínas de Plantas/genética
Proteínas de Plantas/metabolismo
Água/fisiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Photosynthetic Reaction Center Complex Proteins); 0 (Photosystem II Protein Complex); 0 (Plant Proteins); 059QF0KO0R (Water); 9035-40-9 (Cytochrome b6f Complex)
[Em] Mês de entrada:1602
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150226
[St] Status:MEDLINE
[do] DOI:10.1104/pp.114.255794



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