柽柳ThGSTT1基因的抗旱耐盐表达分析

The Expression Analysis of a ThGSTT1 Gene from Tamarix hispida under Salt and Drought Stress

[目的]研究柽柳ThGSTT1基因的抗旱耐盐表达。[方法]通过对柽柳7个转录组分析,克隆获得一条谷胱甘肽转移酶基因,通过Blast比对及进化分析其结构,并采用qPCR分析基因的抗旱耐盐表达。[结果]该基因为谷胱甘肽Theta家族基因,因此命名为ThGSTT1基因;该基因编码的蛋白氨基酸残基数为231,分子量为26.1 kDa,理论等电点为7.14。表达谱分析显示,ThGSTT1在柽柳根和叶中的表达不同,具有一定的组织表达特异性。qPCR分析结果表明,盐胁迫明显诱导了ThGSTT1基因的表达,叶中胁迫7 d表达量为对照的7.48倍,根中胁迫9 d时最大。PEG胁迫下ThGSTT1基因的表达明显受抑制,根中胁迫第3天的表达仅为对照的23.7%,而叶中胁迫第5 d表达量最低,为对照的12.7%。[结论]谷胱甘肽转移酶是一种重要的抗逆保护酶类,进行抗旱耐盐表达分析具有重要意义。

[Objective] To study ThGSTT1 gene from Tamarix hispida under salt and drought stress.[Method] a full length cDNA of glutathione transferase gene was cloned from 7 transcriptome cDNA library of Tamarix hispida.[Result] The results of blast and phylogenetic tree showed that this gene was belonged to GST Theta family,so named as ThGSTT1.ThGSTT1 encoded protein of 231 amino acid residues with the molecular mass 26.1 kDa and theoretical isoelectric point of 7.14.The expression profile of ThGSTT1 under NaHCO3 showed difference between roots and leaves.The results of real time RT-PCR showed that the expressions of ThGSTT1 were obvious induced after NaCl stress.In leaves,the expression level was highest at 7 d,it was 7.48 fold compared to the control; while in roots,its expression was 2.08 fold at 9 d.Under PEG stress,ThGSTT1 was mainly down-regulated,and in roots it was down regulated to 23.7％ at 3 d,while in leaves it was expressed lowest at 5 d,only 12.7％ of its in the control.[Conclusion] Glutathione transferase gene is an important protecting enzyme in plants,drought and salt resistance expression analysis has significance.