马铃薯StNAC72基因克隆及表达分析

Cloning and Function Analysis of the StNAC72 Gene from Potato(Solanum tuberosum)

NAC转录因子在应答非生物胁迫中具有重要的调节作用。本研究以宁薯4号叶为材料,应用RT-PCR技术从已建立的转录组测序数据库中获得了马铃薯StNAC72基因全长序列,对其序列特征进行生物信息学分析;并应用real-time PCR技术分析了干旱和干旱后复水处理下根、匍匐茎和叶中该基因的时空表达特征。结果表明,StNAC72基因开放阅读框长1 074 bp,编码357个氨基酸,含有典型的NAM结构域。进化树聚类分析显示,该基因与拟南芥AtNAC072/RD26亲缘关系最近,属于NAC蛋白的SNAC(stressassociated NAC)组成员。转录水平表达分析显示,StNAC72基因表达量存在组织表达差异;干旱处理致使匍匐茎和叶中StNAC72均表现出上调表达模式,干旱处理后匍匐茎中StNAC72表达量较无处理的匍匐茎中上调近10倍;根中该基因对胁迫应答变化不明显,但表达量相较对照根中上调近1倍。干旱后复水处理促使StNAC72表达量下调,且以匍匐茎中该基因对胁迫应答最为显著,说明该基因可能参与干旱及水分刺激信号传导过程。研究结果为应用StNAC72改良马铃薯抗逆能力提供了基础理论数据。

NAC transcription factors play crucial roles in response to abiotic stress in plant. In this study, the full length c DNA of StNAC72 gene was cloned from leaves of NINGSHU 4 by RT-PCR, whose nucleotides and amino acid sequence were analyzed by bioinformatics software. Expression pattern of StNAC72 in roots, stolon tip and leaves under drought stress and rewatering after drought was detected by real-time PCR technology. The results showed that the full-length open reading frame of StNAC72 was 1 074 bp and the encoded StNAC72 comprising357 amino acids. The N-terminal amino acid residue of StNAC72 contained a typical NAM conserved domain.Phylogenetic analysis demonstrated that StNAC72 shared high homology with AtNAC072/RD26, and it belong to SNAC(stress-associated NAC) subfamily of NAC family. Transcription and expression analysis showed that expression level of StNAC72 exhibited tissue expression differences. StNAC72 was up-regulated in the tuber tip and leaves under drought stress. And the expression level of StNAC72 was 10 times higher in stolon tip under drought stress than that in control stolon. Changes of StNAC72 expression level in roots were not as distinct as that in tuber tip and leaves. However, StNAC72 in roots under drought stress was up-regulated almost 1 time as much as that in control group. Compared with StNAC72 expression level in drought stress groups, they exhibited down-regulated pattern in all of the rewatering after drought stress groups and the gene expression in stolon tips showed the most significant changes. Those showed that the StNAC72 might play an important role in drought stress response and water stimulation signal transduction process and our data provided basic theoretical evidence for the future research of improvement of adversity ability in potato.