植物响应联合胁迫机制的研究进展

自然界中, 植物通常面对多重联合胁迫。在全球气候变化日益加剧的背景下, 多重联合胁迫对植物生长发育及作物产量形成的不利影响日益显著。阐明植物响应和适应联合胁迫的生理与分子机制, 对人们理解植物对自然环境的适应机理, 及培育耐受联合胁迫的新品种有重要意义。研究表明, 植物响应联合胁迫的机制是特异的, 不能简单地从单一胁迫响应叠加来推断。植物遭受联合胁迫时, 各种生理、代谢和信号途径相互作用, 使得植物响应联合胁迫非常复杂。该文综述了植物响应联合胁迫的生理与分子机理的最新进展, 并阐述了植物响应联合胁迫的研究方法。     

植物响应联合胁迫机制的研究进展

自然界中, 植物通常面对多重联合胁迫。在全球气候变化日益加剧的背景下, 多重联合胁迫对植物生长发育及作物产量形成的不利影响日益显著。阐明植物响应和适应联合胁迫的生理与分子机制, 对人们理解植物对自然环境的适应机理, 及培育耐受联合胁迫的新品种有重要意义。研究表明, 植物响应联合胁迫的机制是特异的, 不能简单地从单一胁迫响应叠加来推断。植物遭受联合胁迫时, 各种生理、代谢和信号途径相互作用, 使得植物响应联合胁迫非常复杂。该文综述了植物响应联合胁迫的生理与分子机理的最新进展, 并阐述了植物响应联合胁迫的研究方法。     

植物CBL-CIPK信号系统的功能及其作用机理

由类钙调磷酸酶B蛋白CBLs及其互作蛋白激酶CIPKs组成的信号系统是植物逆境胁迫信号传导的关键调控节点,是近几年植物逆境胁迫生理与分子生物学研究领域中的重要热点之一。文章主要介绍了CBLs和CIPKs基本功能结构域、CBL-CIPK信号系统在各种生物和非生物逆境胁迫响应、营养物质吸收及植物激素应答中的生物学功能及其作用机理。     

Deciphering the regulatory mechanisms of abiotic stress tolerance in plants by genomic approaches

Environmental constraints that include abiotic stress factors such as salt, drought, cold and extreme temperatures severely limit crop productivity. Improvement of crop plants with traits that confer tolerance to these stresses was practiced using traditional and modern breeding methods. Molecular breeding and genetic engineering contributed substantially to our understanding of the complexity of stress response. Mechanisms that operate signal perception, transduction and downstream regulatory factors are now being examined and an understanding of cellular pathways involved in abiotic stress responses provide valuable information on such responses. This review presents genomic-assisted methods which have helped to reveal complex regulatory networks controlling abiotic stress tolerance mechanisms by high-throughput expression profiling and gene inactivation techniques. Further, an account of stress-inducible regulatory genes which have been transferred into crop plants to enhance stress tolerance is discussed as possible modes of integrating information gained from functional genomics into knowledge-based breeding programs. In addition, we envision an integrative genomic and breeding approach to reveal developmental programs that enhance yield stability and improve grain quality under unfavorable environmental conditions of abiotic stresses.     

Signal transduction during cold, salt, and drought stresses in plants

Abiotic stresses, especially cold, salinity and drought, are the primary causes of crop loss worldwide. Plant adaptation to environmental stresses is dependent upon the activation of cascades of molecular networks involved in stress perception, signal transduction, and the expression of specific stress-related genes and metabolites. Plants have stress-specific adaptive responses as well as responses which protect the plants from more than one environmental stress. There are multiple stress perception and signaling pathways, some of which are specific, but others may cross-talk at various steps. In this review article, we first expound the general stress signal transduction pathways, and then highlight various aspects of biotic stresses signal transduction networks. On the genetic analysis, many cold induced pathways are activated to protect plants from deleterious effects of cold stress, but till date, most studied pathway is ICE-CBF-COR signaling pathway. The Salt-Overly-Sensitive (SOS) pathway, identified through isolation and study of the sos1, sos2, and sos3 mutants, is essential for maintaining favorable ion ratios in the cytoplasm and for tolerance of salt stress. Both ABA-dependent and -independent signaling pathways appear to be involved in osmotic stress tolerance. ROS play a dual role in the response of plants to abiotic stresses functioning as toxic by-products of stress metabolism, as well as important signal transduction molecules and the ROS signaling networks can control growth, development, and stress response. Finally, we talk about the common regulatory system and cross-talk among biotic stresses, with particular emphasis on the MAPK cascades and the cross-talk between ABA signaling and biotic signaling.     

Combinatorial Interactions of Biotic and Abiotic Stresses in Plants and Their Molecular Mechanisms: Systems Biology Approach

Plants are continually facing biotic and abiotic stresses, and hence, they need to respond and adapt to survive. Plant response during multiple and combined biotic and abiotic stresses is highly complex and varied than the individual stress. These stresses resulted alteration of plant behavior through regulating the levels of microRNA, heat shock proteins, epigenetic variations. These variations can cause many adverse effects on the growth and development of the plant. Further, in natural conditions, several abiotic stresses causing factors make the plant more susceptible to pathogens infections and vice-versa. A very intricate and multifaceted interactions of various biomolecules are involved in metabolic pathways that can direct towards a cross-tolerance and improvement of plant’s defence system. Systems biology approach plays a significant role in the investigation of these molecular interactions. The valuable information obtained by systems biology will help to develop stress-resistant plant varieties against multiple stresses. Thus, this review aims to decipher various multilevel interactions at the molecular level under combinatorial biotic and abiotic stresses and the role of systems biology to understand these molecular interactions.     

Oxylipins and plant abiotic stress resistance

Oxylipins are signaling molecules formed enzymatically or spontaneously from unsaturated fatty acids in all aerobic organisms. Oxylipins regulate growth, development, and responses to environmental stimuli of organisms. The oxylipin biosynthesis pathway in plants includes a few parallel branches named after first enzyme of the corresponding branch as allene oxide synthase, hydroperoxide lyase, divinyl ether synthase, peroxygenase, epoxy alcohol synthase, and others in which various biologically active metabolites are produced. Oxylipins can be formed non-enzymatically as a result of oxygenation of fatty acids by free radicals and reactive oxygen species. Spontaneously formed oxylipins are called phytoprostanes. The role of oxylipins in biotic stress responses has been described in many published works. The role of oxylipins in plant adaptation to abiotic stress conditions is less studied; there is also obvious lack of available data compilation and analysis in this area of research. In this work we analyze data on oxylipins functions in plant adaptation to abiotic stress conditions, such as wounding, suboptimal light and temperature, dehydration and osmotic stress, and effects of ozone and heavy metals. Modern research articles elucidating the molecular mechanisms of oxylipins action by the methods of biochemistry, molecular biology, and genetics are reviewed here. Data on the role of oxylipins in stress signal transduction, stress-inducible gene expression regulation, and interaction of these metabolites with other signal transduction pathways in cells are described. In this review the general oxylipin-mediated mechanisms that help plants to adjust to a broad spectrum of stress factors are considered, followed by analysis of more specific responses regulated by oxylipins only under certain stress conditions. New approaches to improvement of plant resistance to abiotic stresses based on the induction of oxylipin-mediated processes are discussed.     

Plant–rhizobacteria interactions alleviate abiotic stress conditions

Root-colonizing non-pathogenic bacteria can increase plant resistance to biotic and abiotic stress factors. Bacterial inoculates have been applied as biofertilizers and can increase the effectiveness of phytoremediation. Inoculating plants with non-pathogenic bacteria can provide 'bioprotection' against biotic stresses, and some root-colonizing bacteria increase tolerance against abiotic stresses such as drought, salinity and metal toxicity. Systematic identification of bacterial strains providing cross-protection against multiple stressors would be highly valuable for agricultural production in changing environmental conditions. For bacterial cross-protection to be an effective tool, a better understanding of the underlying morphological, physiological and molecular mechanisms of bacterially mediated stress tolerance, and the phenomenon of cross-protection is critical. Beneficial bacteria-mediated plant gene expression studies under non-stress conditions or during pathogenic rhizobacteria–plant interactions are plentiful, but only few molecular studies on beneficial interactions under abiotic stress situations have been reported. Thus, here we attempt an overview of current knowledge on physiological impacts and modes of action of bacterial mitigation of abiotic stress symptoms in plants. Where available, molecular data will be provided to support physiological or morphological observations. We indicate further research avenues to enable better use of cross-protection capacities of root-colonizing non-pathogenic bacteria in agricultural production systems affected by a changing climate.     

Plant stress surveillance monitored by ABA and disease signaling interactions

Abiotic and biotic stresses are the major factors that negatively impact plant growth. In response to abiotic environmental stresses such as drought, plants generate resistance responses through abscisic acid (ABA) signal transduction. In addition to the major role of ABA in abiotic stress signaling, ABA signaling was reported to downregulate biotic stress signaling. Conversely recent findings provide evidence that initial activation of plant immune signaling inhibits subsequent ABA signal transduction. Stimulation of effector-triggered disease response can interfere with ABA signal transduction via modulation of internal calcium-dependent signaling pathways. This review overviews the interactions of abiotic and biotic stress signal transduction and the mechanism through which stress surveillance system operates to generate the most efficient resistant traits against various stress condition.     

NAC转录因子在植物抗病和抗非生物胁迫反应中的作用

NAC转录因子是植物特有的一类转录因子,其共同特点是在N端含有一段高度保守、由约150个氨基酸组成的NAC结构域,而C端为高度变异的转录调控区。研究表明,NAC转录因子不仅参与植物生长发育的调控,而且在植物抗逆反应中具有重要的调控作用。文章着重介绍NAC转录因子在植物抗逆反应中的作用及其调控机制,并简要讨论NAC转录因子生物学功能的研究方向。