香蕉3个Tau类谷胱甘肽硫转移酶基因的克隆及序列分析

Molecular Cloning and Expression of Three Glutathione S-transferases Gene from Banana(Musa acuminata L.AAA group,cv. Brazilian)

为了获得香蕉抗逆相关基因,通过随机克隆测序和RACE(rapid-amplification of cDNA ends)的方法从香蕉根系cDNA文库中获得3个谷胱甘肽硫转移酶基因,命名为MaGSTU1、MaGSTU2和MaGSTU3(GenBank登录号分别为:KC261934、KC261935和KC261936)。经5′RACE获得3个GST基因全长,分别包含1个627、675和699 bp的最大开放阅读框(Open Reading Frame,ORF),分别编码208、224和232个氨基酸的蛋白质。蛋白质序列同源比对发现其含有完整的GST_N_Tau和GST_C_Tau结构域。系统发育树显示所有Tau类GST基因聚成一大支,充分说明本研究克隆的3个基因为Tau类GST基因。这些结果为进一步分析该类基因的功能和今后香蕉抗逆分子育种提供了基础资料。

Glutathione S-transferases（GST）are muhifunctional detoxification enzymes that participate in a variety of cellular processes, including stress responses. In this study, we reported the molecular characteristics of three GST genes（MaGSTU1, MaGSTU2 and MaGSTU3）cloned from banana（Musa acuminate L. AAA group, cv. Brazilian） using a RACE-PCR-based strategy. Three full-length cDNA of GST genes were amplified from banana roots cDNA, containing 627 bp, 699 bp and 675 bp ORF, and encoding 208, 232 and 224 amino acids, respectively. Protein alignment showed that they contained the complete GST N Tau and GST_C_Tau domains. Phylogenetic analysis showed that the deduced amino acid sequences of MaGSTUs also had high similarity to Tau class GSTs of other plant species. The results are of potential importance not only for further study on the nature and function of banana GSTs but also for the improvement of crops for abiotic stress resistance by genetic engineering.