小麦3个NAC转录因子基因克隆与功能分析

Cloning and Characterization of Three NAC-like Transcription Factor Genes in Wheat

NAC类转录因子参与植物基因在不同条件、不同发育期的表达调控,在植物的发育、生长及对外界的各种生物和非生物因子的胁迫应答中起关键的调控作用。本研究对非亲和条锈菌小种CYR32侵染诱导的抗条锈病基因Yr5近等基因系Taichung29*6/Yr5的cDNA文库进行筛选及同源克隆,获得了小麦3个NAC类转录因子的cDNA序列。序列分析结果表明,这3个转录因子都具有DNA结合结构域,即NAC结构域,且氨基酸序列在该结构域的A、B、C、D和E5个亚区高度保守;同时发现这3个NAC类转录因子都有核定位信号及相关的转录调控功能区域。通过系统进化树分析,发现其中之一的TaNAC1属于NAC转录因子家族第Ⅰ组的NAP亚组,TaNAC3属于ATAF1亚组,TaNAC5属于NAM亚组;根据系统进化树和相关基因的功能分析,我们推测小麦转录因子TaNAC1、TaNAC3和TaNAC5可能参与植物生长发育调控或对生物、非生物胁迫作出的应答反应。

Transcription factors involved in the expression of plant genes in different conditions and regulation of different developmental stages,and they plays a key role in plant development,growth,and response to various biotic and abiotic stress factors.In this study,we isolated three novel cDNA clones encoding NAC transcription factor by homologous PCR cloning method and by screening a cDNA library of a near-isogenic line Taichung 29＊6/Yr5 of wheat resistance gene Yr5 induced by inoculating with race CYR32 of Puccinia striiformis.Amino acids translation and sequence analysis indicted that one DNA binding domain,also named NAC domain,lies in the N-terminal of every transcription factor,especially that the amino acids in the subdomain A,B,C,D and E comprising of NAC domain were highly conserved.Phylogenic tree showed that TaNAC1 and TaNAC3 belonged to NAP and ATAF1 group,respectively,and TaNAC5 belonged to NAM group.Based on the phylogenic tree analysis and comparison of the function annotation of related genes,we predicated that TaNAC1,TaNAC3 and TaNAC5 may involved in plant development progresses and abiotic/biotic stress responses.