大麦转录因子基因HvNAC1的克隆及功能初探

Isolation of the Transcription Factor HvNAC1 and Preliminary Investigation on Its Function

NAC转录因子家族是植物中最大的转录因子家族之一,在植物的生长发育及植物参与生物与非生物胁迫过程中起重要作用。本研究通过分析感染大麦温和花叶病毒(Barley mild mosaic virus,BaMMV)的大麦转录组测序结果,获得表达上调的基因 HORVU5Hr1G011650,基因注释为 HvNAC1。通过生物信息学分析发现该基因全长915 bp,编码304个氨基酸,分子量为33.3 kDa,理论等电点为9.21,在14～141位氨基酸之间含有NAC转录因子家族保守结构域。系统进化分析发现,该基因与小麦、拟南芥中的NAC转录因子同源性较高。组织表达分析发现,该基因在大麦的不同生长时期均有表达,在结实后期和外颖壳中表达量较高。农杆菌介导的烟草亚细胞定位实验表明,该基因定位于细胞核中。在酵母实验中,发现 HvNAC1具有完整的转录因子活性。

NAC family is one of the most abundant transcription factor families in plant. Those members are known in roles of plant growth and development as well as responses to abiotic and biotic stresses. Taking advantage of the transcriptome datasets, here we identified a Barley mild mosaic virus(BaMMV)-infected up-regulation gene HORVU5 Hr1 G011650(named HvNAC1). This NAC gene contains a 915 bp open reading frame that encodes 304 amino acids with a conserved domain(between 14 th and 141 st amino acids). By bioinformatics prediction, the deduced protein represented molecular weight of 33.3 kDa and theoretical isoelectric point of 9.21. The transcripts of this gene were detected in samples from different growth stages of barley, while its transcript was abundant at the stage of late grain filling stage and in outer glume. By Agrobacterium-mediated transformation in tobacco, HvNAC1 was localized to the nucleus. In yeast, HvNAC1 showed the binding and activation activities, suggesting a function as a typical transcription factor.