摘要：

作为植物抵御多种逆境胁迫的重要调节因子,植物热激转录因子(Hsf)家族基因数目多,结构、特性和功能复杂多样。植物Hsf不仅通过直接转录调控热激蛋白和相关基因的表达,参与对多种逆境胁迫的响应和适应过程,还介导植物诸多生命活动过程。自20世纪80年代酵母Hsf被首先克隆以来,多个物种的Hsf家族被识别和研究,模式植物番茄和拟南芥Hsf研究比较早且相对深入,研究主要集中在HsfA族,B族研究较少,C族报道更少。随着全球气候变化,极端高温事件频发,已严重威胁小麦、玉米等粮食作物的产量和品质,深入研究作物耐热性机制从而挖掘功能基因、通过生物技术方法改良作物的耐热性,是抵抗高温逆境的关键。大田作物中Hsf家族数目大小不等,基因组复杂,研究起步晚。为此,植物生理与分子生物学研究室从2009年开始对作物Hsf家族基因进行研究,依据最新的基因组信息,确定了家族基因数目及核酸和蛋白质结构特性、明确了家族基因的时空表达特性及其对多种非生物逆境的响应规律。克隆获得多个基因并借助遗传转化和基因编辑技术创制转基因材料和突变体,对其耐热性以及抗逆性调控功能多层面进行了鉴定,并对下游调控机制进行了深入解析。研究不仅丰富了大田作物耐热性调控理论基础,也为作物耐热性研究和生物育种提供优异新种质。目前,关于Hsf的研究主要集中在功能鉴定和对下游基因的转录调控方面,其上游哪些组分通过何种方式介导Hsf参与耐热性调控方面的研究还缺乏证据,机制尚不清楚。基于本研究室多年来对小麦、玉米Hsf家族的研究结果,结合他人的相关研究报道,详述了近年来植物Hsf在抗逆性响应和适应过程中调控功能、机制及其主要研究进展,以期为深入阐明Hsf家族的作用及其调控网络提供理论依据,为耐热生物育种挖掘强效的基因资源和备选位点。

关键词: 植物热激转录因子, 非生物胁迫, 功能与机制, 调控网络

Abstract:

As a key regulating factor in response to various abiotic stresses,plant heat shock transcription factor (Hsf) has a big family,and diverse structure,characteristics and functions.Hsf not only directly regulates Hsp and other relative gene expression and participates in the processes of response and adaption to various abiotic stresses,but also mediates many life activities regulation.Since the first Hsf was cloned from yeast in the 1980s,more and more Hsfs from other species have been identified and studied.In the previous reports,the identification of the Hsf family in plants was performed only in model species such as Arabidopsis and tomato.Furthermore,the studies is mainly focused on the HsfA subfamily,with few studies on the HsfB subfamily.And,the precise function of HsfC family is also largely unknown.With global climate change,the frequent occurrence of extremely high temperature events has seriously threatened the yield and quality of wheat,maize and other crops.To deal with the threat posed by heat stress,unraveling the mechanism of thermotolerance,identifying functional the targeted Hsfs and improving stress tolerance of crop through biotechnology methods is important.The number of Hsf family in field crops is various,the genome is complex,and the related research started lately compared with model species.To this end,our laboratory began to study the Hsf family of crops in 2009.Based on the latest genomic information,we confirmed the number of members,the modular structure and the spatio-temporal expression pattern of Hsf family.At the same time,with the help of transgenic wheat and mutant by genetic transformation and the CRISPR/Cas9 clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR-associated protein mediated genome editing technology,several Hsfs were cloned and their regulatory functions of thermotolerance were identified,and some mechanism of thermotolerance was clarified.Our research not only enriched the theoretical basis of thermotolerance,but also provided new germplasm for biological breeding.At present,many studies have reported on functional identification and transcriptional regulation of Hsfs,however,evidences lack on which upstream component mediate Hsf's participation in regulation of thermotolerance,and the related mechanism is still unknown.Based on previous research results about wheat and maize Hsf families of lab,and many relative reports published in public,we reviewed the roles and mechanisms of plant Hsf in regulating process reported in recent years,aiming to promote research in illustrating the extensive and special roles and regulation network of plant Hsf family further,and dig useful genes and selective QTLs for biological breeding for plant thermotolerance.

Key words: Plant heat shock transcription factor, Abiotic stresses, Function and mechanism, Regulation network