马铃薯HSP17.7基因的克隆及其对高温逆境的响应

Cloning of HSP17.7 Gene and Its Response to High Temperature Stress in Potato

热激蛋白和植物对高温的响应密切相关,同时在植物生长发育调控和逆境抵抗等方面具有重要作用。该研究克隆了马铃薯热激蛋白基因StHSP 17.7(GenBank登录号为XP_006350804.1),对其全长cDNA序列进行了相关生物信息学分析,并利用qRT-PCR分析StHSP17.7基因在高温胁迫下的差异表达特性。结果显示:(1)StHSP 17.7全长755 bp,包含465 bp开放阅读框,编码154个氨基酸。(2)StHSP17.7分子质量约为17.62 kD,等电点7.91,为亲水性蛋白,C端含有保守序列Ⅰ和Ⅱ组成的ACD结构域,属于典型的sHSPs家族成员。(3)系统进化分析发现马铃薯小分子热激蛋白归为12个亚家族,其中StHSP17.7与马铃薯HSP17.6蛋白亲缘关系较近,属于小分子热激蛋白C的Ⅰ类家族成员;基因结构分析显示,在马铃薯48个sHSP基因中,StHSP17.7基因不含内含子,含1个内含子的基因有23个,占47.9%。(4)qRT-PCR分析显示,高温能够快速诱导StHSP 17.7基因表达,且基因表达量呈爆发式变化,在24 h达到最高值。研究表明,StHSP 17.7基因明显参与了马铃薯对高温的响应。

Plant heat-shock proteins are representative proteins that respond to high temperatures and play an important role in regulating plant growth and development and resisting adversity.In this study,HSP 17.7 gene from Solanum tuberosum was cloned by RT-PCR and bioinformatic characters were analyzed.The expression level of StHSP 17.7 gene under high temperature stress was analyzed by qRT-PCR.The results showed that:(1)full-length sequence of StHSP 17.7 gene was 755 bp.It contains an open reading frame of 465 bp and 154 amino acids were encoded.(2)The StHSP 17.7 gene encoding protein was a hydrophilic protein with molecular weight of 17.62 kD and the isoelectric point is 7.91.The functional structure domain analysis showed that the C-terminal of the protein contained an ACD domain consisting of conserved sequenceⅠand conserved sequenceⅡ,typically belonging to the sHSPs family member.(3)Phylogenetic analysis showed that sHSPs of S.tuberosum was clustered into 12 subfamilies.The StHSP17.7 protein was closely related to the HSP17.6 protein of S.tuberosum,and belongs to the family of small heat shock protein CⅠ.Gene structure analysis showed that among 48 StHSPs genes from S.tuberosum,StHSP 17.7 gene does not contain intron,and other 23 genes contained one introns,accounting for 47.9%of all the genes in the family.(4)qRT-PCR analysis showed that StHSP 17.7 gene expression was rapidly induced by high temperatures,and the gene expression level showed an explosive change,reaching the highest value in 24 h.The results suggest that StHSP 17.7 gene is very sensitive to heat stress and may play an important role in response to high-temperature stress in potatoes.