高等植物WRKY转录因子家族的演化及功能研究进展

WRKY转录因子是植物转录调节因子的最大家族之一,并且是调节植物许多生物过程的信号网络的组成部分。WRKY转录因子通过其保守结构域与靶基因启动子区域的W-box特异性结合,调节靶基因的表达,进而调控植物的叶片衰老、种子萌发与休眠、开花等生长发育过程外,还参与调控植物生物和非生物胁迫的响应过程。本文用代表性植物基因组数据,对WRKY的基因演化作了归纳,综述了近二十年来国内外WRKY转录因子的相要研究进展,并介绍了该转录因子在植物生物胁迫和非生物胁迫应答及生长发育过程中的调控作用。      

花生AhDREB转录因子对逆境胁迫的响应

DREB(Dehydration Responsive Element Binding Protein)转录因子是AP2/ERF类转录因子的一个亚家族,在植物抗逆过程中发挥关键作用。为更深入地理解花生Ah DREB转录因子的特点与功能,本研究采用生物信息学的方法对Ah DREB基因家族进行了分析。本研究发现花生中共有22个Ah DREB基因,并进一步分析了Ah DREB基因家族成员基因结构特点、遗传进化关系、组织表达情况以及逆境胁迫响应。研究结果表明,Ah DREB转录因子可以分成6类,每一类基因结构具有明显不同的特点。Ah DREB在22个正常不同组织中表达量均较低,但在逆境胁迫条件下,部分Ah DREB基因表达明显提高。本研究为深入分析Ah DREB基因在逆境胁迫中的作用奠定了理论基础。     

小麦转录因子 TaDREB6基因启动子的克隆及活性分析

启动子的分析有助于解析植物抵御不良环境的机制。植物DREB转录因子参与对干旱、低温和高盐等胁迫的响应,在抗逆中起着重要作用。本研究利用反向PCR方法从小麦中克隆获得DREB转录因子TaDREB6基因启动子,长度为1 705 bp。PLACE和PlantCARE分析发现,TaDREB6基因启动子包含多种胁迫相关元件。构建由TaDREB6基因启动子驱动的GUS植物表达载体,转化小麦成熟胚愈伤组织,组织化学染色结果表明,TaDREB6基因启动子是诱导型启动子,受干旱、低温、盐、脱落酸和水杨酸等胁迫诱导。Real-time PCR显示,TaDREB6基因受多种胁迫诱导表达,与TaDREB6启动子活性分析结果一致,这些结果为进一步分析DREB转录因子的功能提供了依据。     

大豆干旱响应GRAS基因筛选及GmGRAS27的生物信息学和逆境表达分析

GRAS转录因子在植物抵抗非生物胁迫过程中发挥了重要作用,为了研究大豆GRAS基因在干旱胁迫中的响应,以挖掘大豆GRAS转录因子在干旱等非生物胁迫响应中的功能和分子机制提供分子基础,本研究利用基因表达综合数据库(Gene Expression Omnibus,GEO)筛选响应干旱胁迫的大豆GRAS基因,利用PlantC...     

大豆GmDof4和GmDof11基因的非生物胁迫诱导表达及启动子分析

Dof家族是典型的植物特异性锌指转录因子家族,在植物中可以对非生物胁迫产生应答.为初步研究大豆Dof家族主要转录因子编码基因GmDof4和GmDof11在大豆抗非生物胁迫过程中的作用及调控原理,本研究通过实时荧光定量PCR检测大豆幼苗中GmDof4和GmDof11基因在非生物胁迫下的表达情况,并使用PlantCARE在线数据库分析两个基因上游启动子的作用元件.结果显示:GmDof4在干旱、高盐、高温和低温胁迫下表达量升高;GmDof11在干旱、高盐和低温胁迫下表达量升高,在高温胁迫下表达量下降.启动子顺式作用元件预测结果显示,GmDof4启动子中含有1个厌氧诱导元件、1个低温响应元件和1个MYB转录因子结合位点;GmDof11启动子中含有3个厌氧诱导元件、2个低温响应元件、1个防御和胁迫响应元件和1个MYB转录因子结合位点.此外,它们的启动子序列中还含有脱落酸响应元件、茉莉酸甲酯响应元件、赤霉素响应元件以及生长素响应元件.结果说明GmDof4和GmDof11的启动子区域含有逆境相关顺式作用元件,能够参与大豆对非生物胁迫的应答.     

转录因子DREB在植物抗逆中的应用

DREB转录因子即干旱应答元件结合蛋白质,它能与启动子中的DRE/CRT顺式元件特异结合,激活许多逆境诱导基因的表达,从而增强植物对逆境胁迫的耐受力。综述了DREB转录因子与植物抗旱性的关系,DREB转录因子的克隆与鉴定,以及它的表达载体的构建。     

参与植物盐胁迫调控的转录因子研究进展

盐胁迫是影响植物生长、发育和作物产量的主要环境因子.在盐胁迫的响应和适应过程中,植物会产生许多生理生化反应,许多基因被激活,导致大量参与盐胁迫的蛋白质的积累.胁迫响应基因的表达主要由特定的转录因子(TF)调控,转录因子通常可以激活或抑制多个靶基因的转录.目前已发现多个胁迫响应的转录因子,对它们调控的基因启动子区的顺式作用元件也有很多研究.转录因子及其顺式作用元件不仅是基因表达的分子开关,而且在信号传导过程中是信号转导通路的终端.在这篇文章中,我们重点总结了参与植物盐胁迫调控的几类转录因子,包括NAC、bZIP和bHLH的研究进展.     

参与植物盐胁迫调控的转录因子研究进展（英文）

盐胁迫是影响植物生长、发育和作物产量的主要环境因子。在盐胁迫的响应和适应过程中,植物会产生许多生理生化反应,许多基因被激活,导致大量参与盐胁迫的蛋白质的积累。胁迫响应基因的表达主要由特定的转录因子(TF)调控,转录因子通常可以激活或抑制多个靶基因的转录。目前已发现多个胁迫响应的转录因子,对它们调控的基因启动子区的顺式作用元件也有很多研究。转录因子及其顺式作用元件不仅是基因表达的分子开关,而且在信号传导过程中是信号转导通路的终端。在这篇文章中,我们重点总结了参与植物盐胁迫调控的几类转录因子,包括NAC、bZIP和bHLH的研究进展。     

小麦SPL家族基因在非生物胁迫下的表达分析

SQUAMOSA promoter binding protein like(SPL)是一类在植物中广泛存在的转录因子家族,在调控植物生长发育、响应逆境胁迫等方面发挥着重要作用。为解析小麦中SPL家族基因响应非生物胁迫的机理,本研究采用生物信息学的方法在全基因组范围内对小麦SPL基因家族成员进行鉴定,并对鉴定到的SPL基因进行表达模式分析。结果表明,在全基因组范围内共鉴定到56个小麦SPL基因,其中27个是miR156的靶基因;系统进化分析发现,56个小麦SPL基因聚类为7个亚家族。基于转录组数据对表达模式进行分析,发现36个小麦SPL基因与非生物胁迫响应相关,响应缺氮、缺磷、高盐、低温、干旱、高温胁迫以及热旱共胁迫的基因分别有12、16、22、6、13、14和21个,其中TraesCS3D02G425800同时响应7种非生物胁迫。qRT PCR验证结果与转录组数据基本一致。     

茶树WOX基因家族的鉴定和表达模式分析

WOX转录因子在植物的生长发育和非生物胁迫响应中起着重要的调控作用。文章基于全基因组数据,从茶树基因组中鉴定出29个WOX基因,并对其基因结构、进化关系、保守域、染色体定位进行分析,同时分析了它们在PEG诱导的干旱胁迫、盐胁迫处理中的转录组数据。结果表明,29个CsWOX(茶树WOX)基因在茶树染色体上分布不均;根据进化关系将茶树WOX基因分为4类;基因结构和保守基序分析发现相同亚家族的基因结构和保守结构域基本一致;基因表达分析显示,CsWOX基因在花和果实组织中具有较高的表达水平,且部分基因随着叶片成熟度的增加,表达水平升高;不同的Cs?WOX基因在PEG诱导的干旱胁迫、盐胁迫处理下存在差异表达,说明CsWOX基因广泛参与茶树生长发育并在响应非生物胁迫中发挥重要作用。该结果将为进一步研究WOX基因在调控茶树生长发育和非生物胁迫响应中的作用提供一些有价值的信息,为茶树WOX基因的功能研究与利用提供科学依据。     

Defensive Role of Plant Hormones in Advancing Abiotic Stress-Resistant Rice Plants

Consistent climatic perturbations have increased global environmental concerns, especially the impacts of abiotic stresses on crop productivity. Rice is a staple food crop for the majority of the world’s population. Abiotic stresses, including salt, drought, heat, cold and heavy metals, are potential inhibitors of rice growth and yield. Abiotic stresses elicit various acclimation responses that facilitate in stress mitigation. Plant hormones play an important role in mediating the growth and development of rice plants under optimal and stressful environments by activating a multitude of signalling cascades to elicit the rice plant’s adaptive responses. The current review describes the role of plant hormone-mediated abiotic stress tolerance in rice, potential crosstalk between plant hormones involved in rice abiotic stress tolerance and significant advancements in biotechnological initiatives including genetic engineering approach to provide a step forward in making rice resistance to abiotic stress.     

Role of ABA in integrating plant responses to drought and salt stresses

Since their early migration from aquatic environments to the land, plants have had to cope with periodic and unpredictable environmental stresses during growth and development. Surviving such stresses over a long evolutionary scale led plants to acquire mechanisms by which they can sensitively perceive incoming stresses and regulate their physiology accordingly. The plant hormone abscisic acid (ABA) plays a major role in plant responses to stress. Although rapid production of ABA in response to drought and salt stresses is essential to define ABA as a stress hormone, an equally rapid catabolism of ABA when such stresses are relieved is also essential in that role. Since ABA mediates so many stress responses, the initial perception of dehydration and the subsequent changes in gene expression that lead to rapid ABA biosynthesis constitute the most important stress signal transduction pathway among all the plant responses to stresses. Identification of the genes involved and understanding their roles during stress perception and physiological regulation has become an important and exciting research field in recent years. This review covers mainly our understanding of this aspect. ABA-induced changes in gene expression and their roles in physiological regulation are dealt with in less detail.     

Down-Regulated Expression of RACK1 Gene by RNA Interference Enhances Drought Tolerance in Rice

The receptor for activated C-kinase 1 (RACK1) is a highly conserved scaffold protein with versatile functions, and plays important roles in the regulation of plant growth and development. Transgenic rice plants, in which the expression of RACK1 gene was inhibited by RNA interference (RNAi), were studied to elucidate the possible functions of RACK1 in responses to drought stress in rice. Real-time PCR analysis showed that the expression of RACK1 in transgenic rice plants was inhibited by more than 50%. The tolerance to drought stress of the transgenic rice plants was higher as compared with the non-transgenic rice plants. The peroxidation of membrane and the production of malondialdehyde were significantly lower, and the superoxide dismutase activity in transgenic rice plants was significantly higher than those in non-trangenic rice plants. It is suggested that RACK1 negatively regulated the redox system-related tolerance to drought stress of rice plants.     

Molecular Approaches to Improve Salt Resistance in Crops: Facts and Perspectives

SUMMARY

Because of the expansion of agriculture into marginal environments, enhancement of crop resistance to soil salinity is becoming a frequent objective for breeders. The tools offered by molecular biology to transfer a single or a few genes provide a major hope to reduce the negative impact of broad gene transfer that takes place in wide-cross hybridizations. Due to the presence of osmotic and toxic components in the growth response of plants to salt stress, any attempt to improve plant performance in saline environments should ensure the maintenance of an adequate flux of water into plant tissues, and also avoid the build up of ions into the cell compartments where they can exert toxic effects. Besides, reduction of injury effects due to salinity on plant tissues is a highly desirable objective. Transgenic plants overexpressing ion transporters able to exclude Na⁺ into vacuoles, the enzymes required for the biosynthesis of several osmocompatible, organic solutes, or the enzymes participating in detoxification pathways, have been obtained. Some of these transgenic plants display an enhanced growth relative to their wild type parents in saline environments, although the way in which this resistance is achieved remains essentially unknown. A fourth and promising way to engineer salt resistance in plants is the attempt to manipulate gene regulatory pathways. The extent to which these experiences, mainly with model plants, could be extrapolated to crop plants growing in the field is discussed. It is proposed that a combination of different molecular approaches could be helpful to achieve enhanced salt resistance in crop plants.     

Role of LOX3 Gene in Alleviating Adverse Effects of Drought and Pathogens in Rice

Lipoxygenase 3 (LOX3) is a major component of the LOX isozymes in mature rice seeds. To investigate the role of LOX3 gene under stresses, a plant expression vector containing antisense cDNA of LOX3 was constructed. Rice varieties Wuyunjing 7 and Kasalath were transformed by the Agrobacterium-mediated method and transgenic rice plants were generated. PCR and Southern blot results showed that the antisense LOX3 gene was integrated into the rice genome. Analyses of embryo LOX3 deletion and semi-quantitative RT-PCR confirmed the antisense suppression of LOX3 gene in transgenic plants. The T2 antisense plants of LOX3 were sensitive to drought stress, rice blast and bacterial blight compared with non-transgenic plants. These results suggest that the LOX3 gene might function in response to stresses.     

RNA干涉下调RACK1基因表达增强水稻抗旱能力

 RACK1是一种多功能支架蛋白,广泛参与植物生长发育过程的调节。利用RNA干涉技术抑制水稻RACK1基因的表达,分析了RACK1基因在响应干旱胁迫中的功能。实时定量PCR对获得的转基因植株的RACK1基因表达分析结果表明,转基因水稻RACK1基因表达受抑制程度达50%左右。与非转基因水稻（对照）相比,转基因水稻耐干旱能力显著强于对照,其膜的过氧化酶和丙二醛的产生显著低于对照,而超氧化物歧化酶活性极显著高于对照。表明RACK1蛋白质调节水稻对干旱胁迫的耐性,并且这种调节在很大程度上与植株体内的氧化还原系统有关。     

长穗偃麦草EeSnRK2.6基因克隆及生物信息学分析

蔗糖非发酵相关蛋白激酶家族2(SnRK2)基因家族受各种逆境胁迫诱导表达,在提高植物的抗逆性中发挥着至关重要的作用。为继续深入挖掘有效的抗逆相关基因资源并为转基因小麦提供重要候选基因,基于同源克隆方法从抗旱、耐盐性极强的长穗偃麦草中克隆了EeSnRK2.6基因的cDNA序列,该基因全长1 096bp,编码364个氨基酸,推测分子量为41.73kD,等电点为5.98,是亲水性氨基酸,共有18处磷酸化位点和1处跨膜域。氨基酸序列同源性分析发现,长穗偃麦草EeSnRK2.6基因与其他目前已报道的抗逆效果显著的SnRK2家族基因有较高同源性,同大豆SnRK2.6基因同源性达到95%,且具有典型的丝氨酸/苏氨酸类蛋白激酶保守域。系统进化树分析表明,EeSnRK2.6与SbSnRK2.6属于同一进化分枝上。因此,推测该基因属于SnRK2基因家族成员,可能在参与逆境胁迫反应、增强植物的抗逆性中起着重要作用。     

偃麦草ErABF1基因克隆及功能分析

抗逆相关bZIP (Basic leucine zipper) 转录因子家族基因主要参与ABA、干旱、高盐等胁迫应答反应,其过表达能够显著增强植物的抗逆性。本研究从偃麦草（Elytrigria repens L.）中分离到一个抗逆相关 ErABF1（E. repens ABA Binding Factor 1）基因,氨基酸序列比对分析发现,该基因与小麦、玉米、拟南芥等bZIP转录因子基因同源性较高,亲缘关系较近;ErABF1基因的表达受到ABA、干旱、高盐、低温的强烈诱导;在2% PEG、200 mmol·L^-1 NaCl胁迫培养基上初步功能分析表明, ErABF1过表达提高了转基因烟草对干旱、高盐的胁迫耐性。