拟南芥AtTERT对大肠杆菌非生物胁迫抗性的影响

端粒酶是真核生物中维持染色体末端DNA完整性的一类特殊逆转录酶,研究拟南芥AtTERT对大肠杆菌生长及非生物胁迫的影响,为深入研究TERT蛋白非端粒功能奠定基础.将拟南芥AtTERT转入大肠杆菌,成功构建pET32a-AtTERT原核表达载体,优化诱导条件,纯化并鉴定GST-AtTERT融合蛋白,运用Western b...     

Wheat Lysin-Motif-Containing Proteins Characterization and Gene Expression Patterns under Abiotic and Biotic Stress

Lysin motif (LysM)-containing proteins (LYPs) are important pattern recognition receptors in plants. However, the evolutionary history and characteristics of LYP genes remain largely unclear in wheat. In this study, 62 LYPs were identified at genome wide in wheat. Based on phylogenetic and domain analysis, wheat LYPs were classified into 6 subgroups (group LysMe, LysMn, LYP, LYK, LysMFbox). Syntenic analysis showed the evolution of LYP genes in wheat. RNA-seq data showed that 22 genes were not expressed at any tissue or stress stimulation period. Some LYP and LYK genes were tissue- or stage- specific. The majority of TaLYK5s, TaLYK6s, TaLYP2s and TaLysMns genes were induced under chitin, flg22 and fungal treatment. qRT-PCR analysis showed that 4 genes were upregulated during Puccinia triticina infection with a peak at 18 h post inoculation. Our findings suggested that wheat LYPs may have specific roles in response to fungal infection and provided insights into the function and characteristics of wheat LYP genes.     

拟南芥漆酶基因AtLAC4参与生长及非生物胁迫响应

植物漆酶基因家族在拟南芥(Arabidopsis thaliana)中共有17个成员,目前各基因的具体功能尚不十分清楚.该研究利用过量表达的方法初步分析了拟南芥AtLAC4的功能.GUS染色显示AtLAC4在拟南芥的维管组织中有较强的表达,并在叶片排水器中特异表达.AtLAC4过量表达导致植株木质素含量增多、次生壁加厚、植株变小和莲座叶叶柄变短.ABA对AtLAC4的表达具有明显的诱导作用,AtLAC4过量表达植株对外源ABA敏感;干旱处理后,AtLAC4过量表达植株的耐旱能力比野生型明显增强.以上结果表明,AtLAC4基因在调控植物生长发育及非生物胁迫响应中具有重要作用.     

Rice Mitogen-activated Protein Kinase Gene Family and Its Role in Biotic and Abiotic Stress Response

The mitogen-activated protein kinase （MAPK） cascade is an important signaling module that transduces extracellular stimuli into intracellular responses in eukaryotic organisms. An increasing body of evidence has shown that the MAPK-mediated cellular signaling is crucial to plant growth and development, as well as biotic and abiotic stress responses. To date, a total of 17 MAPK genes have been Identified from the rice genome. Expression profiling, biochemical characterization and/or functional analysis were carried out with many members of the rice MAPK gene family, especially those associated with biotic and abiotic stress responses. In this review, the phylogenetic relationship and classification of rice MAPK genes are discussed to facilitate a simple nomenclature and standard annotation of the rice MAPK gene family. Functional data relating to biotic and abiotic stress responses are reviewed for each MAPK group and show that despite overlapping in functionality, there is a certain level of functional specificity among different rice MAP kinases. The future challenges are to functionally characterize each MAPK, to identify their downstream substrates and upstream kinases, and to genetically manipulate the MAPK signaling pathway in rice crops for the Improvement of agronomically important traits.     

Rice Mitogen-activated Protein Kinase Gene Family and Its Role in Biotic and Abiotic Stress Response

The mitogen-activated protein kinase (MAPK) cascade is an important signaling module that transduces extracellu-lar stimuli into intracellular responses in eukaryotic organisms. An increasing body of evidence has shown that theMAPK-mediated cellular signaling is crucial to plant growth and development, as well as biotic and abiotic stressresponses. To date, a total of 17 MAPK genes have been identified from the rice genome. Expression profiling,biochemical characterization and/or functional analysis were carried out with many members of the rice MAPKgene family, especially those associated with biotic and abiotic stress responses. In this review, the phylogeneticrelationship and classification of rice MAPK genes are discussed to facilitate a simple nomenclature and standardannotation of the rice MAPK gene family. Functional data relating to biotic and abiotic stress responses are re-viewed for each MAPK group and show that despite overlapping in functionality, there is a certain level of functionalspecificity among different rice MAP kinases, The future challenges are to functionally characterize each MAPK, toidentify their downstream substrates and upstream kinases, and to genetically manipulate the MAPK signalingpathway in rice crops for the improvement of agronomically important traits.     

Plant RABs: Role in Development and in Abiotic and Biotic Stress Responses

Endosomal trafficking plays an integral role in various eukaryotic cellular activities and is vital for higher-order functions in multicellular organisms. RAB GTPases are important proteins that influence various aspects of membrane traffic, which consequently influence many cellular functions and responses. Compared to yeast and mammals, plants have evolved a unique set of plant-specific RABs that play a significant role in their development. RABs form the largest family of small guanosine triphosphate (GTP)-binding proteins, and are divided into eight sub-families named RAB1, RAB2, RAB5, RAB6, RAB7, RAB8, RAB11 and RAB18. Recent studies on different species suggest that RAB proteins play crucial roles in intracellular trafficking and cytokinesis, in autophagy, plant microbe interactions and in biotic and abiotic stress responses. This review recaptures and summarizes the roles of RABs in plant cell functions and in enhancing plant survival under stress conditions.     

BRs在植物响应非生物胁迫中的作用

油菜素甾体(brassinosteroids,BRs)是植物界普遍存在的一类多羟基化的植物甾体激素,不仅调节植物的生长发育过程,还参与植物对生物和非生物胁迫的响应.概述了BRs的生物合成途径以及信号转导途径,重点阐述了BRs参与非生物胁迫应答的分子机制,展望了BRs未来的研究方向,为深入理解BRs介导的非生物胁迫调控网...     

蔗糖转化酶在高等植物生长发育及胁迫响应中的功能研究进展

随着分子生物学和测序技术的发展,植物蔗糖转化酶基因的克隆、表达调控及其功能方面的研究取得了长足的进展。综述了近年来蔗糖转化酶在植物生长发育、以及转化酶介导的植物对生物与非生物胁迫等过程中的重要作用,并对该领域今后的研究前景进行了展望。     

ERF转录因子在植物对生物和非生物胁迫反应中的作用

ERF（ethylene responsive factor）转录因子是植物AP2/ERF转录因子超家族的一个亚家族,其特征是蛋白序列中含有一个高度保守的58或59个氨基酸组成的ERF结构域,广泛参与植物生长发育及各种逆境胁迫反应的调控。文章简要介绍ERF转录因子在植物抗生物和非生物胁迫反应中的作用及其可能机制,并讨论了今后的研究重点。     

类受体蛋白激酶与植物非生物胁迫应答

类受体蛋白激酶(receptor-like protein kinase,RLK)是植物信号转导网络中的重要成员,参与介导生长、发育以及逆境胁迫应答等多种细胞代谢过程．在植物细胞中已发现和克隆了富含亮氨酸重复区型(LRR)、凝集素型(lectin-like)和细胞壁相联型(WAK)等不同的RLK亚家族．这些RLK能够感受多种发育和外界环境胁迫信号, 并在植物对非生物胁迫的响应过程中发挥重要的调控作用．本文结合当今国内外研究进展,简述植物RLK的典型结构域特征,详细介绍多种RLK在植物逆境信号识别与转导中发挥的作用,同时对RLK在非生物胁迫应答中的具体作用机制进行了探讨．     

拟南芥神经酰胺酶基因对氧化胁迫的响应

以拟南芥哥伦比亚生态型（Col）和神经酰胺酶突变体为实验材料,通过对突变体的一系列生理生化指标的测定,来研究拟南芥神经酰胺酶基因（AtCER）对H2O2的响应。利用PCR和Northern blot获得了9个AtCER纯合单突变体。不同浓度H2O2处理野生型和突变体后,发现突变体对H2O2的反应比野生型更加敏感。H2O2处理后突变体叶片出现比野生型更严重的黄化现象和坏死斑点,总叶绿素含量也比野生型下降的更快,电导率测定也发现突变体比野生型的电导率增加得更多。抗氧化酶活性的分析结果发现H2O2处理后,突变体的抗氧化酶活性比野生型提高了1．5～3倍。上述研究结果说明AtCER参与了H2O2诱导的氧化胁迫反应。     

Reference Gene Selection for Quantitative Real-Time PCR in Chrysanthemum Subjected to Biotic and Abiotic Stress

Quantitative real-time PCR (RT-qPCR) is a reliable method for assessing gene expression, provided that suitable reference genes are included to normalize the data. The stability of expression of eight potential reference genes, namely, tubulin (alpha-2,4 tubulin), actin, EF1α (elongation factor 1α), UBC (ubiquitin C), GAPDH (glyceraldehyde-3-phosphate dehydrogenase), psaA (photosynthesis-related plastid gene representing photosystem I), PP2Acs (catalytic subunit of protein phosphatase 2A), and PGK (phosphoglycerate kinase), was assessed in chrysanthemum plants subjected to aphid infestation, heat stress or waterlogging stress using geNorm software. The widely used reference gene EF1α performed well for aphid infested plants but poorly for waterlogged ones. The catalytic subunit of protein phosphatase 2A (PP2Acs) was the best performing one during heat and waterlogging stress, but was the worst during aphid infestation. The commonly used reference gene actin was generally the least stable of the set. No single gene was suitable for normalization on its own. The choice of reference gene(s) is an important factor in gene expression studies based on RT-qPCR.     

Plant Polyamines in Reproductive Activity and Response to Abiotic Stress*

In this review we will focus on two areas in which the accumulated evidence for a critical physiological role of polyamines is becoming compelling, i.e. reproductive activity and response to abiotic stress. Regarding reproductive behavior, it seems clear that polyamines are members of the array of internal compounds required for flower initiation, normal floral organ morphogenesis, fruit growth and fruit ripening in particular plant species. Abiotic stresses such as osmotic stress can “turn on” arginine decarboxylase (ADC) genes, resulting in a rapid increase in their mRNA levels. Localization of ADC enzyme in the chloroplast suggests a role of PAs in the maintenance of photosynthetic activity during senescence responses induced by osmotic stress. We envisage that the use of transgenic plants and improved molecular probes will resolve in the near future the physiological significance of stress-induced changes in PA metabolism as well as the role of these compounds in reproductive activity.     

miR482介导的植物生物胁迫响应

植物在生长发育过程中会遇到各种生物胁迫,根据响应过程的不同,可将之分为基于蛋白质的生物胁迫和基于RNA的生物胁迫。miR482是一种植物特有的、已在23个物种中被证实存在的小RNA。miR482参与指导植物次级phasiRNA的合成,其主要靶标为植物庞大的Ⅳ=日§三R尺类家族抗病基因。本文通过整理近年来ETI（effector-triggeredimmunity）相关的NBS-LRR类抗病基因和抗RNA沉默抑制相关miR482级联调控的研究成果,总结出了miR482介导植物两类生物胁迫响应的调控机制。     

异源表达CkLEA1基因增强了拟南芥对非生物胁迫的耐受性

植物在生长过程中会受到各种非生物胁迫的伤害,导致生长发育和产量受到严重影响,胚胎晚期丰富蛋白（late embryogenesis abundant proteins,LEA蛋白）在植物抵抗非生物胁迫过程中起着重要的保护作用。在前期的研究基础上,将受多种胁迫诱导的柠条锦鸡儿CkLEA1（GenBank登录号KC309408）基因转入野生型拟南芥,通过实时荧光定量PCR从7株T₃代纯合体中筛选出3个转基因株系做进一步研究。种子萌发率实验发现,在200 mmol/L NaCl和400 mmol/L甘露醇处理下,转基因株系萌发率均高于野生型拟南芥。干旱处理2周大的幼苗后,转基因株系明显比野生型更抗旱,存活率高于野生型,并且失水率低于野生型。同时,转基因株系积累了较少的丙二醛（MDA）,超氧化物歧化酶（SOD）活性和谷胱甘肽（GSH）含量也高于野生型。这些结果表明,柠条锦鸡儿CkLEA1基因在种子萌发阶段提高了拟南芥对盐和渗透胁迫的耐受性,并且提高了转基因拟南芥幼苗生长阶段对干旱胁迫的抵抗能力。     

Chitinase Gene Expression in Response to Environmental Stresses in Arabidopsis thaliana: Chitinase Inhibitor Allosamidin Enhances Stress Tolerance

The expression levels of three chitinase genes in Arabidopsis thaliana, AtChiA (class III), AtChiB (class I), and AtChiV (class IV), were examined under various stress conditions by semi-quantitative RT-PCR. Under normal growth conditions, the AtChiB and AtChiV genes were expressed in most organs of Arabidopsis plants at all growth stages, whereas the AtChiA gene was not expressed at all. The class III AtChiA gene was expressed exclusively when the plants were exposed to environmental stresses, especially to salt and wound stresses. Treatment of Arabidopsis plants with allosamidin, which inhibits class III chitinases, did not affect the growth rate. Surprisingly, however, the plants treated with allosamidin were more tolerant of abiotic stresses (cold, freezing, heat, and strong light) than the control plants. It also appeared that allosamidin enhances AtChiA and AtChiB expression under heat and strong light stresses. Allosamidin is likely to enhance abiotic stress tolerance, probably through crosstalk between the two signaling pathways for biotic and abiotic stress responses.