Autophagy and its role in plant abiotic stress management

Being unable to move, plants are regularly exposed to changing environmental conditions, among which various types of abiotic stress, such as heat, drought, salt, and so forth. These might have deleterious effects on plant performance and yield. Plants thus need to adapt using appropriate stress responses. One of the outcomes of abiotic stress is the need to degrade and recycle damaged proteins and organelles. Autophagy is a conserved eukaryotic mechanism functioning in the degradation of proteins, protein aggregates, and whole organelles. It was previously shown to have a role in plant abiotic stress. This review will describe the current knowledge regarding the involvement of autophagy in plant abiotic stress response, mechanisms functioning in autophagy induction during stress, and possible direction for future research.     

植物响应非生物胁迫的磷酸化修饰组学研究进展

植物具有固着生活的特点,高温、低温、干旱和盐等生境中常见的非生物胁迫会严重影响植物的生长发育。蛋白质磷酸化是植物应对非生物胁迫的重要机制,主要通过蛋白质的磷酸化和去磷酸化修饰来调控植物细胞对外界胁迫的应激反应,在植物细胞快速传递胁迫信号并激活对胁迫环境的形态、生理和分子水平适应机制的过程中起重要作用。该文主要介绍了植物磷酸化蛋白质的富集、检测和鉴定技术,并对近年来国内外有关植物响应高温、低温、干旱、淹水、盐、养分亏缺和元素毒害等非生物胁迫的磷酸化修饰蛋白组学研究进展进行综述。     

Role of Pathogen-Related Protein 10 (PR 10) under Abiotic and Biotic Stresses in Plants

Members of the Pathogenesis Related (PR) 10 protein family have been identified in a variety of plant species and a wide range of functions ranging from defense to growth and development has been attributed to them. PR10 protein possesses ribonuclease (RNase) activity, interacts with phytohormones, involved in hormone-mediated signalling, afforded protection against various phytopathogenic fungi, bacteria, and viruses particularly in response to biotic and abiotic stresses. The resistance mechanism of PR10 protein may include activation of defense signalling pathways through possible interacting proteins involved in mediating responses to pathogens, degradation of RNA of the invading pathogens. Moreover, several morphological changes have been shown to accompany the enhanced abiotic stress tolerance. In this review, the possible mechanism of action of PR10 protein against biotic and abiotic stress has been discussed. Furthermore, our findings also confirmed that the in vivo Nitric oxide (NO) is essential for most of environmental abiotic stresses and disease resistance against pathogen infection. The proper level of NO may be necessary and beneficial, not only in plant response to the environmental abiotic stress, but also to biotic stress. The updated information on this interesting group of proteins will be useful in future research to develop multiple stress tolerance in plants.     

Plant proteome changes under abiotic stress--contribution of proteomics studies to understanding plant stress response

Plant acclimation to stress is associated with profound changes in proteome composition. Since proteins are directly involved in plant stress response, proteomics studies can significantly contribute to unravel the possible relationships between protein abundance and plant stress acclimation. In this review, proteomics studies dealing with plant response to a broad range of abiotic stress factors--cold, heat, drought, waterlogging, salinity, ozone treatment, hypoxia and anoxia, herbicide treatments, inadequate or excessive light conditions, disbalances in mineral nutrition, enhanced concentrations of heavy metals, radioactivity and mechanical wounding are discussed. Most studies have been carried out on model plants Arabidopsis thaliana and rice due to large protein sequence databases available; however, the variety of plant species used for proteomics analyses is rapidly increasing. Protein response pathways shared by different plant species under various stress conditions (glycolytic pathway, enzymes of ascorbate-glutathione cycle, accumulation of LEA proteins) as well as pathways unique to a given stress are discussed. Results from proteomics studies are interpreted with respect to physiological factors determining plant stress response. In conclusion, examples of application of proteomics studies in search for protein markers underlying phenotypic variation in physiological parameters associated with plant stress tolerance are given.     

植物水通道蛋白的干旱应答机制研究进展

干旱胁迫是严重影响全球作物生产的非生物胁迫之一,研究植物耐旱机制已成为一个重要领域。水通道蛋白是一类特异、高效转运水及其它小分子底物的膜通道蛋白,在植物中具有丰富的亚型,参与调节植物的水分吸收和运输。近10年来,水通道蛋白在植物不同生理过程中的作用,一直受到研究人员的关注,特别是在非生物胁迫方面,而研究表明水通道蛋白在干旱胁迫下对植物的耐旱性起着至关重要的作用,能维持细胞水分稳态和调控环境胁迫快速响应。水通道蛋白在植物耐旱过程中的调控机制及功能较复杂,而关于其应答机制和不同亚型功能性研究的报道甚少。该文综述了植物水通道蛋白的分类、结构、表达调控和活性调节,分别从植物水通道蛋白响应干旱表达调控机制、水通道蛋白基因表达的时空特异性、水通道蛋白基因的表达与蛋白丰度,水通道蛋白基因的耐旱转化四个方面阐明干旱胁迫下植物水通道蛋白的表达,重点阐述其参与植物干旱胁迫应答的作用机制,并提出水通道蛋白研究的主要方向。     

Molecular analysis of Hsp70 mechanisms in plants and their function in response to stress

Studying the strategies of improving abiotic stress tolerance is quite imperative and research under this field will increase our understanding of response mechanisms to abiotic stress such as heat. The Hsp70 is an essential regulator of protein having the tendency to maintain internal cell stability like proper folding protein and breakdown of unfolded proteins. Hsp70 holds together protein substrates to help in movement, regulation, and prevent aggregation under physical and or chemical pressure. However, this review reports the molecular mechanism of heat shock protein 70 kDa (Hsp70) action and its structural and functional analysis, research progress on the interaction of Hsp70 with other proteins and their interaction mechanisms as well as the involvement of Hsp70 in abiotic stress responses as an adaptive defense mechanism.     

植物CBL-CIPK信号系统响应非生物胁迫的调控机制

钙调磷酸酶B蛋白(CBLs)及其互作蛋白激酶(CIPKs)组成的信号系统是非生物逆境响应的重要调控网络。CBL-CIPK系统通过磷酸化感应并解码Ca²⁺信号, 参与植物对非生物胁迫的应答调控。该文综述了CBLs和CIPKs结构、CBLs-CIPKs对不同底物磷酸化及其响应非生物胁迫调控机制的研究进展, 并展望了未来的研究方向, 以期为作物抗逆性遗传改良提供思路。     

Crop Improvement and Abiotic Stress Tolerance Promoted by Moringa Leaf Extract

Moringa leaf extract (MLE) has been shown to promote beneficial outcomes in animals and plants. It is rich in amino acids, antioxidants, phytohormones, minerals, and many other bioactive compounds with nutritional and growth-promoting potential. Recent reports indicated that MLE improved abiotic stress tolerance in plants. Our understanding of the mechanisms underlying MLE-mediated abiotic stress tolerance remains limited. This review summarizes the existing literature on the role of MLE in promoting plant abiotic stress acclimation processes. MLE is applied to plants in a variety of ways, including foliar spray, rooting media, and seed priming. Exogenous application of MLE promoted crop plant growth, photosynthesis, and yield under both nonstress and abiotic stress conditions. MLE treatment reduced the severity of osmotic and oxidative stress in plants by regulating osmolyte accumulation, antioxidant synthesis, and secondary metabolites. MLE also improves mineral homeostasis in the presence of abiotic stress. Overall, this review describes the potential mechanisms underpinning MLE-mediated stress tolerance.     

Molecular mechanism of salicylic acid-induced abiotic stress tolerance in higher plants

Salicylic acid (SA), a key signaling molecule in higher plants, has been found to play a role in the response to a diverse range of phytopathogens and is essential for the establishment of both local and systemic-acquired resistance. Recent studies have indicated that SA also plays an important role in abiotic stress-induced signaling, and studies on SA-modulated abiotic tolerance have mainly focused on the antioxidant capacity of plants by altering the activity of anti-oxidative enzymes. However, little information is available about the molecular mechanisms of SA-induced abiotic stress tolerance. Here, we review recent progress toward characterizing the SA-regulated genes and proteins, the SA signaling pathway, the connections and differences between SA-induced tolerances to biotic and abiotic stresses, and the interaction of SA with other plant hormones under conditions of abiotic stress. The future prospects related to molecular tolerance of SA in response to abiotic stresses are also further summarized.     

Plant abiotic stress: deciphering remedial strategies for emerging problem

Growing in their natural environment, plants often encounter unfavorable environmental conditions that interrupt normal plant growth and productivity. Drought, high/low temperature and saline soils are the most common abiotic stresses that plants encounter in their natural environments. Molecular and genomic analyses have facilitated gene discovery and enabled genetic engineering using several functional or regulatory genes that are known to be involved in stress response and preliminary tolerance, to activate specific or broad pathways related to abiotic stress tolerance in plants. Through the use of transgenic technology, goals such as production of plants with desired traits that were unattainable with traditional selection programs are achieved. This review deals with recent advancement in understanding the role of various stress responsive genes and their critical importance for explaining the control mechanism of abiotic stress tolerance and engineering stress tolerant crops based on the expression of specific stress related genes.     

蛋白质组学在植物逆境胁迫研究中的进展

蛋白质组学是后基因组时代研究的热点领域之一,自从蛋白质组这个概念被提出以来,其研究一直受到广泛关注,其研究技术也有了极大地进步。植物时刻都面临各种非生物胁迫,包括干旱、冷、盐、金属等,在长期进化过程中,植物形成独特的机制来响应逆境,然而目前对于植物如何适应逆境的分子机制尚未完全阐明。因此蛋白质组学作为一种强有力的研究技术手段,将为研究植物响应胁迫的分子机制提供理论支撑。介绍了蛋白质组学的产生背景、研究技术手段及植物在各种胁迫条件下的蛋白质组学研究、植物亚细胞器的蛋白质组学研究状况,同时对植物蛋白质组学的发展前景进行了展望。     

Identification of changes in Triticum aestivum L. leaf proteome in response to drought stress by 2D-PAGE and MALDI-TOF/TOF mass spectrometry

Drought is an abiotic stress that strongly influences plant growth, development and productivity. To gain a better understanding of the drought-stress responses at physiological and molecular level in wheat plants (Triticum aestivum cv. KTC86211), we performed a comparative physiological and proteomics analysis. Eight-day-old wheat seedlings were treated with polyethylene glycol-simulated drought stress for 0, 24, 48 and 72 h. Drought treatment resulted in alterations of morphology, increased relative electrolyte leakage and reduced length and weight on leaf and root. Stress-induced proteome changes were analyzed by two-dimensional gel electrophoresis in conjunction with MALDI-TOF/TOF. Twenty-three spots differed significantly between control and treated plants following 48 h of drought stress, with 19 upregulated, and 4 downregulated, in leaf tissues. All of the differentially expressed protein spots were identified, revealing that the majority of proteins altered by drought treatment were involved in reactive oxygen species scavenging enzymes and photosynthesis. Other proteins identified were involved in protein metabolism, cytoskeleton structure, defense response, acid metabolism and signal transduction. All proteins might contribute cooperatively to reestablish cellular homeostasis under drought stress. The present study not only provides new insights into the mechanisms of acclimation and tolerance to drought stress in wheat plants, but also provides clues for improving wheat’s drought tolerance through breeding or genetic engineering.     

大豆类钙调磷酸酶B亚基GmCBL1互作候选蛋白的筛选

Ca2+是非生物胁迫信号转导途径中的重要信号分子,植物类钙调磷酸酶B亚基蛋白(CBL,calcineurin B-like proteins)是一类重要的钙信号受体蛋白,主要通过与其他蛋白的特异结合传递信号,使植物形成对非生物胁迫的响应。本实验室已经获得大豆Gm CBL1基因,功能鉴定显示Gm CBL1增强了转基因拟南芥对非生物胁迫的耐性。为了进一步研究Gm CBL1的作用机理,本研究构建诱饵载体p GBKT7::Gm CBL1,利用酵母双杂交技术筛选大豆Gm CBL1的互作蛋白。通过对筛选获得的106个蛋白基因测序和Blast比对分析,并根据其可能的生理功能对这些候选蛋白归类,整理得到4类蛋白:能量代谢相关蛋白、修饰蛋白、防御蛋白、钙信号转导相关蛋白。筛选得到候选蛋白的功能预测初步表明,大豆Gm CBL1参与多条信号途径,为进一步研究探索大豆CBL介导的抗逆信号转导途径奠定了基础。     

Beyond osmolytes and transcription factors: drought tolerance in plants <Emphasis Type="Italic">via</Emphasis> protective proteins and aquaporins

Mechanisms of drought tolerance have been studied by numerous groups, and a broad range of molecules have been identified to play important roles. A noteworthy response of stressed plants is the accumulation of novel protective proteins, including heat-shock proteins (HSPs) and late embryogenesis abundant (LEA) proteins. Identification of gene regulatory networks of these protective proteins in plants will allow a wide application of biotechnology for enhancement of drought tolerance and adaptation. Similarly, aquaporins are involved in the regulation of water transport, particularly under abiotic stresses. The molecular and functional characterization of protective proteins and aquaporins has revealed the significance of their regulation in response to abiotic stresses. Herein, we highlight new findings regarding the action mechanisms of these proteins. Finally, this review also surveys the current advances in engineering drought tolerant plants, particularly the engineering of protective proteins (sHSPs and LEA) and aquaporins for imparting drought stress tolerance in plants.     

植物蛋白质组学研究进展

 蛋白质组学是后基因组时代功能基因组学研究的新兴学科和热点领域。该文简要介绍了蛋白质组学产生的科学背景、研究方法和研究内容。蛋白质组学研究方法主要有双向聚丙烯酰胺凝胶电泳（2D-PAGE）、质谱(Mass-spectrometric)技术、蛋白质芯片（Protein chips）技术、酵母双杂交系统（Yeast two-hybrid system）、植物蛋白质组数据库等。其应用的范围包括植物群体遗传学、在个体水平上植物对生物和非生物环境的适应机制、植物的发育和组织器官的分化过程,以及不同亚细胞结构在生理生态过程中的作用等诸多方面。同时对植物蛋白质组学的发展前景进行了展望。     

Proteomics reveals new salt responsive proteins associated with rice plasma membrane

The signaling processes in plants that initiate cellular responses to biotic and abiotic factors are believed to be located in the plasma membrane (PM). A better understanding of the PM proteome response to environmental stresses might lead to new strategies for improving stress-tolerant crops. A sub-cellular proteomics approach was applied to monitor changes in abundance of PM-associated protein in response to salinity, a key abiotic stress affecting rice productivity worldwide. Proteome was extracted from a root plasma-membrane-rich fraction of a rice salt tolerant variety, IR651, grown under saline and normal conditions. Comparative two-dimensional electrophoresis revealed that 24 proteins were differentially expressed in response to salt stress. From these, eight proteins were identified by mass spectrometry analysis. Most of the proteins identified are likely to be PM-associated and are known to be involved in several important mechanisms of plant adaptation to salt stress. These include regulation of PM pumps and channels, membrane structure, oxidative stress defense, signal transduction, protein folding, and the methyl cycle. To investigate the correlation between mRNA and protein level in response to salinity, we performed quantitative Real-Time PCR analysis of three genes that were salt responsive at the protein level, including 1,4-Benzoquinone reductase, a putative remorin and a hypersensitive induced response protein. No concordance was detected between the changes in levels of gene and protein expression. Our results indicate that the proteomics approach is suitable for expression analysis of membrane associated proteins under salt stress.