WRKY转录因子是一个大的植物转录因子家族。该转录因子家族最显著的特征是家族各成员至少包含一个WRKY结构域,该结构域的N-端有一个高度保守的WRKYGQK基序,C-端为一个锌指类似结构域(zinc-finger-like motif),一般组成为C-X_(4-5)-C-X_(22-23)-H-X-H。WRKY转录因子通过WRKY结构域与下游目标基因启动子区的W-box进行特异性结合从而调控目标基因的表达。研究表明,WRKY蛋白除了广泛参与植物种子萌发与休眠、叶片衰老、代谢、激素信号转导外,还参与生物和非生物胁迫等生理生化反应过程的调控等新功能。综述了国内外有关WRKY转录因子的研究进展,讨论了其在植物生长发育以及应对生物和非生物胁迫过程中发挥的调控功能,以期为全面研究WRKY转录因子家族的结构和功能提供新的观点。
WRKY transcription factors( TFs) are typically characterized by a WRKY domain and belonged to a large class of TFs in plants. The WRKY domain contains a highly conserved core sequence of WRKYGQK at its Nterminal,and a C-terminal zinc finger-like motif,which is generally C-X_(4-5)-C-X_(22-23)-H-X-H. WRKY proteins could bind specifically to the W-box elements in the promoter of the downstream target genes via the WRKY DNA-binding domain for transcriptional regulation. Accumulated studies showed that the WRKY protein family was widely involved in processes of seed germination and dormancy,leaf senescence,metabolism,hormone signaling,and biotic and abiotic stresses in plants. Also,regulatory networks of WRKY TFs were illuminated. This paper reviewed the recent progresses on WRKY TFs,mainly focusing on the biological functions of WRKY TFs in response to biotic and abiotic stresses as well as in plant growth and development. Additionally,WRKY proteins that play ‘double-edged sword'roles in responses to biotic stresses were illustrated.