水稻干旱响应基因OsERF74的克隆和功能的初步分析

Cloning and Functional Analysis of Rice Drought Response Gene OsERF74 in Rice

ERF (Ethylene-responsive factor)转录因子家族是AP2-EREBP (APETALA2 and ethylene-responsive element binding proteins, AP2/ERF)超家族中的一个具有较多成员的家族,其在植物中广泛存在并在植物生长发育过程中发挥重要作用。在水稻中ERF转录因子家族成员的OsERF74为水稻干旱响应模块7的节点基因。本研究从水稻品种‘日本晴’中克隆了OsERF74,通过生物信息学和蛋白质系统发育树分析显示OsERF74为ERF类转录因子,具有高度保守的AP2结构域,并在其N端具有跨膜结构域;在烟草中对OsERF74进行亚细胞定位显示其定位于细胞膜上;OsERF74在水稻营养生长和生殖生长时期的各个组织中均有表达,而在苗期的根和叶组织中OsERF74的表达受到多种激素和非生物胁迫的调节;为了解OsERF74基因功能,构建并获得了超表达转基因植株。通过高渗透胁迫下的种子萌发实验显示OsERF74超表达能够增强水稻种子在高渗透胁迫下的萌发率。本研究初步探究了OsERF74的特性与功能,为进一步挖掘水稻干旱响应功能基因提供基础。

The ERF(Ethylene-responsive factor)transcription factor family is a family with a large members in the AP2-EREBP(APETALA2 and ethylene-responsive element binding proteins,or AP2/ERF)superfamily,which is ubiquitous in plants.ERF family plays an important role in the growth and development of plants.OsERF74,a member of the ERF transcription factor family in rice,is the node gene of rice drought response module 7(Zhang et al.,2012).In this study,OsERF74 was cloned from the rice variety"Nipponbare",and bioinformatics and protein phylogenetic tree analysis showed that OsERF74 is an ERF transcription factor with a highly conserved AP2 domain and a transmembrane domain at its N-terminus;Subcellular localization of OsERF74 in tobacco showed that it was localized on the cell membrane;OsERF74 was expressed in various tissues during the vegetative and reproductive growth stages of rice,while the expression of OsERF74 in the root and leaf of the seedling stage was regulated by a variety of hormones and different abiotic stress;In order to understand the function of OsERF74, an overexpression transgenic plant was constructed and obtained. Seedgermination experiments under high osmotic stress show that OsERF74 overexpression can enhance thegermination rate of rice seeds under high osmotic stress. This study initially explored the characteristics andfunctions of OsERF74, laying a foundation for further mining of rice drought-responsive functional genes.