香蕉MaNHX5关键耐盐氨基酸位点的鉴定及验证  

Identification and verification of key salt-tolerant amino acid sites of banana MaNHX5

作　　者：徐亚 滕梦鑫 乔飞[2] 江行玉[3] 周扬[1] 李新国[1] XU Ya;TENG Mengxin;QIAO Fei;JIANG Xingyu;ZHOU Yang;LI Xinguo(School of Horticulture,Hainan University,Haikou 570228,Hainan,China;Tropical Crops Genetic Resources Institute,Chinese Academy of Tropical Agricultural Sciences,Haikou 570100,Hainan,China;College of Tropical Crops,Hainan University,Haikou 570228,Hainan,China)

机构地区：[1]海南大学园艺学院,海南海口570228 [2]中国热带农业科学院热带作物品种资源研究所,海南海口570100 [3]海南大学热带作物学院,海南海口570228

出　　处：《生物工程学报》2022年第5期1946-1952,共7页Chinese Journal of Biotechnology

基　　金：国家自然科学基金(31760549,32160679)。

摘　　要：为提高香蕉NHX基因的耐盐性,从巴西蕉(Musa acuminata L. AAA group)中克隆到一个MaNHXs基因家族的MaNHX5基因,利用生物信息学方法预测了Ma NHX5关键耐盐氨基酸位点和突变前后蛋白质结构的变化,通过定点突变技术将Ma NHX5蛋白的276位丝氨酸(S)成功突变为天冬氨酸(D),利用AXT3盐敏感突变酵母进行功能回补试验。结果表明,将突变后的MaNHX5基因转入AXT3盐敏感突变酵母,200 mmol/L NaCl处理下,突变酵母耐盐性显著提高。由此推测Ma NHX5蛋白的Ser276对香蕉Na+跨液泡膜运输起重要作用。In order to improve the salt tolerance of banana NHX genes, we cloned a MaNHX5 gene from Musa acuminata L. AAA group and predicted the key salt-tolerant amino acid sites and mutant protein structure changes of MaNHX5 by using bioinformatics tools. The 276-position serine(S) of MaNHX5protein was successfully mutated to aspartic acid(D) by site-directed mutagenesis, and the AXT3salt-sensitive mutant yeast was used for a functional complementation test. The results showed that after the mutated MaNHX5 gene was transferred to AXT3 salt-sensitive mutant yeast, the salt tolerance of the mutant yeast was significantly improved under 200 mmol/L NaCl treatment. It is hypothesized that Ser276 of MaNHX5 protein plays an important role in the transport of Na+ across the tonoplast.

关 键 词：香蕉 NHX基因 耐盐性 定点突变 

分 类 号：S668.1[农业科学—果树学]