Non-coding small RNAs responsive to abiotic stress in wheat (Triticum aestivum L.)

Plant small RNAs are emerging as significant components of epigenetic processes and of gene networks involved in development and homeostasis. In this paper, to identify small RNAs in wheat, 2,076 small RNAs were identified in a small RNA library from leaf, root, and spike. These small RNAs mapped to non-coding regions the CDS region of protein-coding genes and 5' UTR and 3' UTR regions. The expression of small RNAs in seedling leaves, roots, and spikes were analyzed by northern blot, which indicates that some small RNAs were responsive to abiotic stress treatments including heat, cold, salt and dehydration.     

Involvement of polyamines in plant response to abiotic stress

Environmental stresses are the major cause of crop loss worldwide. Polyamines are involved in plant stress responses. However, the precise role(s) of polyamine metabolism in these processes remain ill-defined. Transgenic approaches demonstrate that polyamines play essential roles in stress tolerance and open up the possibility to exploit this strategy to improve plant tolerance to multiple environmental stresses. The use of Arabidopsis as a model plant enables us to carry out global expression studies of the polyamine metabolic genes under different stress conditions, as well as genome-wide expression analyses of insertional-mutants and plants over-expressing these genes. These studies are essential to dissect the polyamine mechanism of action in order to design new strategies to increase plant survival in adverse environments.     

Participation of annexin At1 in plant response to abiotic stress

Annexins are calcium-dependent phospholipid-binding proteins existing both in animal and plant cells. Mammalian and especially human annexins were examined for many years, and their functions in these organisms are already well known, but it is not the case for plant annexins. On the basis of existing literature and experimental evidence, it can be proposed that plant annexins may have a role in stress response. Annexin At1 of Arabidopsis thaliana (AnnAt1) is one of eight proteins of this family in A. thaliana. In its sequence many potentially functional domains are found, owing to that this protein can play an important role in stress response of the organism. Considering literature data and our own experiments one can postulate that AnnAt1 has weak peroxidase activity and form oligomers in hydrogen peroxide-dependent manner. This can be important in response to oxidative stress. Also we found that this protein forms ion channel in pH-dependent manner. This phenomenon may have particular significance in maintaining calcium homeostasis in the cell and calcium signaling, therefore AnnAt1 may play different roles in regulating stress response of plant. This is extremely important because plants during growth and development have to cope different stress factors like drought, deficiency or excess of mineral compounds in the soil, as well as low or high temperatures.     

Non-coding RNAs: Functional roles in the regulation of stress response in Brassica crops

Brassica crops face a combination of different abiotic and biotic stresses in the field that can reduce plant growth and development by affecting biochemical and morpho-physiological processes. Emerging evidence suggests that non-coding RNAs (ncRNAs), especially microRNAs (miRNAs) and long ncRNAs (lncRNAs), play a significant role in the modulation of gene expression in response to plant stresses. Recent advances in computational and experimental approaches are of great interest for identifying and functionally characterizing ncRNAs. While progress in this field is limited, numerous ncRNAs involved in the regulation of gene expression in response to stress have been reported in Brassica. In this review, we summarize the modes of action and functions of stress-related miRNAs and lncRNAs in Brassica as well as the approaches used to identify ncRNAs.     

植物应答非生物胁迫的代谢组学研究进展

代谢组学技术是研究植物代谢的理想平台, 通过现代检测分析技术对胁迫环境下植物中代谢产物进行定性和定量分析, 可以监测其随时间变化的规律。而各种组学平台包括基因组学、转录组学及代谢组学的整合, 更是一个强有力的工具箱, 将所获得的不同组学的信息联系起来, 有利于从整体研究生物系统对基因或环境变化的响应, 如可判断代谢物的变化是从哪一个层面开始发生的, 帮助人们揭开复杂的植物胁迫应答机制。该文对近期代谢组学技术及其与蛋白质组学、基因组学技术相结合探索植物应答非生物胁迫的研究进行了综述。代谢组学的应用, 拓展了对植物耐受非生物胁迫分子机制的认识, 开展更多这方面的研究, 再通过植物代谢组学、转录组学、蛋白质组学和基因组学整合, 有助于从整体水平上把握植物胁迫应答机制。     

Small RNAs as big players in plant abiotic stress responses and nutrient deprivation

Abiotic stress is one of the primary causes of crop losses worldwide. Much progress has been made in unraveling the complex stress response mechanisms, particularly in the identification of stress responsive protein-coding genes. In addition to protein coding genes, recently discovered microRNAs (miRNAs) and endogenous small interfering RNAs (siRNAs) have emerged as important players in plant stress responses. Initial clues suggesting that small RNAs are involved in plant stress responses stem from studies showing stress regulation of miRNAs and endogenous siRNAs, as well as from target predictions for some miRNAs. Subsequent studies have demonstrated an important functional role for these small RNAs in abiotic stress responses. This review focuses on recent advances, with emphasis on integration of small RNAs in stress regulatory networks.     

钙离子在植物抵抗非生物胁迫中的作用

钙离子(Ca2+)是植物生长发育所必需的一种大量元素,它同时作为重要信使参与调节植物对环境胁迫的抗逆过程。本文综述了钙离子相关的植物抗逆研究领域最新进展,如Ca2+调节胞内[Na+]/[K+]、调节胞内脱落酸(abscisic acid,ABA)浓度、稳定细胞壁及细胞膜、识别Ca2+/Ca2+依赖蛋白激酶系统以及起始抗逆基因转录,为后续植物细胞Ca2+在环境胁迫下的浓度、分布的实时变化等研究提供一定的基础支撑。     

Lipid signalling in plant responses to abiotic stress

Lipids are one of the major components of biological membranes including the plasma membrane, which is the interface between the cell and the environment. It has become clear that membrane lipids also serve as substrates for the generation of numerous signalling lipids such as phosphatidic acid, phosphoinositides, sphingolipids, lysophospholipids, oxylipins, N‐acylethanolamines, free fatty acids and others. The enzymatic production and metabolism of these signalling molecules are tightly regulated and can rapidly be activated upon abiotic stress signals. Abiotic stress like water deficit and temperature stress triggers lipid‐dependent signalling cascades, which control the expression of gene clusters and activate plant adaptation processes. Signalling lipids are able to recruit protein targets transiently to the membrane and thus affect conformation and activity of intracellular proteins and metabolites. In plants, knowledge is still scarce of lipid signalling targets and their physiological consequences. This review focuses on the generation of signalling lipids and their involvement in response to abiotic stress. We describe lipid‐binding proteins in the context of changing environmental conditions and compare different approaches to determine lipid–protein interactions, crucial for deciphering the signalling cascades.     

The role of small RNAs in abiotic stress

It was recently discovered that plants respond to environmental stress not only with a specific gene expression programme at the mRNA and protein level but also small RNAs as response modulators play an important role. The small RNAs lead to cleavage or translational inhibition of mRNAs via complementary target sites. Different examples are described where small RNAs have been shown to be involved in stress responses. A link between hormonal action and small RNA activities has frequently been observed thus coupling exogenous factors with endogenous transmitters. Using the CDT-1 gene from the desiccation tolerant plant Craterostigma plantagineum as an example, it is discussed that generation of novel small RNAs could be an evolutionary pathway in plants to adapt to extreme environments.     

植物凝集素类受体激酶参与非生物胁迫响应的研究进展

植物在生长发育过程中会受到各种胁迫因子的影响,非生物胁迫是其中极其重要的一类。类受体激酶(receptor-like kinases, RLKs)是植物中广泛存在的一类蛋白,能够快速有效地对胁迫因子作出响应,最终引起一系列生物效应。凝集素类受体激酶(lectin receptor-like kinases, LecRLKs)是RLKs的一个亚族,其具有细胞外凝集素结构域、跨膜结构域和细胞内激酶结构域三个结构域。根据细胞外凝集素结构域的不同可分为L、G和C三种不同类型。近年来,大量的研究表明植物凝集素类受体激酶在非生物胁迫响应中发挥重要作用。LecRLKs通过识别非生物胁迫相关的信号分子,激活下游的信号通路,如MAPK通路、ROS通路、钙信号通路等,调节基因表达和蛋白质翻译以增强植物的抗逆性。该文概述了植物凝集素类受体激酶的结构特征及其分类,并系统综述了LecRLKs在盐胁迫、低温胁迫、干旱胁迫、机械损伤和植物激素等非生物胁迫响应中的功能和作用机制,同时也对LecRLKs的未来研究方向作出了展望。该文不仅为深入了解植物凝集素类受体激酶参与非生物胁迫响应的功能提供了参考,而且为利用LecRLKs进行作物抗逆育种改良提供了理论依据。     

植物MYB转录因子与非生物胁迫响应研究

MYB转录因子家族是植物中最大的转录因子家族之一,在植物体内的多种生理生化反应中起着关键性作用,其中一项重要功能就是对非生物逆境的应答。这类转录因子通过调控生长发育,影响代谢产物的合成和影响激素信号等多方面参与非生物逆境的应答。介绍了MYB转录因子的结构特点和分类上的新发现,并综述了近几年MYB转录因子家族在植物响应干旱、高温、低温和高盐等非生物胁迫方面的研究进展。     

The function of small RNAs in plant biotic stress response

Small RNAs(s RNAs) play essential roles in plants upon biotic stress. Plants utilize RNA silencing machinery to facilitate pathogen-associated molecular pattern-triggered immunity and effector-triggered immunity to defend against pathogen attack or to facilitate defense against insect herbivores. Pathogens, on the other hand, are also able to generate effectors and s RNAs to counter the host immune response. The arms race between plants and pathogens/insect herbivores has triggered the evolution of s RNAs,RNA silencing machinery and pathogen effectors. A great number of studies have been performed to investigate the roles of s RNAs in plant defense, bringing in the opportunity to utilize s RNAs in plant protection. Transgenic plants with pathogen-derived resistance ability or transgenerational defense have been generated, which show promising potential as solutions for pathogen/insect herbivore problems in the field. Here we summarize the recent progress on the function of s RNAs in response to biotic stress, mainly in plant-pathogen/insect herbivore interaction,and the application of s RNAs in disease and insect herbivore control.     

In vivo role of nitric oxide in plant response to abiotic and biotic stress

Over the past few years, nitric oxide (NO) has emerged as an important regulator in many physiological events, especially in response to abiotic and biotic stress. However, the roles of NO were mostly derived from pharmacological studies or the mutants impaired NO synthesis unspecifically. In our recent study, we highlighted a novel strategy by expressing the rat neuronal NO synthase (nNOS) in Arabidopsis to explore the in vivo role of NO. Our results suggested that plants were able to perform well in the constitutive presence of nNOS, and provided a new class of plant experimental system with specific in vivo NO release. Furthermore, our findings also confirmed that the in vivo NO is essential for most of environmental abiotic stresses and disease resistance against pathogen infection. Proper level of NO may be necessary and beneficial, not only in plant response to the environmental abiotic stress, but also to biotic stress.     

Long Non-coding RNAs in the Cytoplasm

An enormous amount of long non-coding RNAs (lncRNAs) transcribed from eukaryotic genome are important regulators in different aspects of cellular events. Cytoplasm is the residence and the site of action for many lncRNAs. The cytoplasmic lncRNAs play indispensable roles with multiple molecular mechanisms in animal and human cells. In this review, we mainly talk about functions and the underlying mechanisms of lncRNAs in the cytoplasm. We highlight relatively well-studied examples of cytoplasmic lncRNAs for their roles in modulating mRNA stability, regulating mRNA translation, serving as competing endogenous RNAs, functioning as precursors of microRNAs, and mediating protein modifications. We also elaborate the perspectives of cytoplasmic lncRNA studies.     

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.