浮萍LmGSTU1基因克隆及其提高大肠杆菌镉耐受性的分析  

Cloning of Duckweed LmGSTU1 Gene and Analysis of Improving Cadmium Tolerance in Escherichia coli

作　　者：娄遵义 刘兆菊 毕星怡 任丽丽 杨贵利 Lou Zunyi;Liu Zhaoju;Bi Xingyi;Ren Lili;Yang Guili(College of Life Sciences,Guizhou University,Guiyang 550025,Guizhou,China;State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550025,Guizhou,China)

机构地区：[1]贵州大学生命科学学院,贵州贵阳550025 [2]中国科学院地球化学研究所环境地球化学国家重点实验室,贵州贵阳550025

出　　处：《山地农业生物学报》2025年第1期76-84,共9页Journal of Mountain Agriculture and Biology

基　　金：国家自然科学基金项目(32001203);贵州省科技计划重点项目(黔科合基础-ZK[2022]重点021);贵州大学实验室开放项目(SYSKF2024-69);贵州大学大学生创新创业训练计划项目(gzusc2023113)。

摘　　要：谷胱甘肽-S-转移酶(Glutathione-S-transferases,GST)是由大型基因家族编码的多功能酶,在植物耐受重金属胁迫方面具有重要作用。本研究以镉(Cadmium,Cd)超富集浮萍的cDNA为模板扩增出LmGSTU1基因,并进一步对LmGSTU1基因进行生物信息学分析。结果表明:LmGSTU1基因全长675 bp,可编码224个氨基酸,存在GST-C和GST-N两个亚家族结构域。LmGSTU1蛋白为带负电荷稳定的酸性亲水性蛋白,含有14个磷酸化位点,二级结构以α-螺旋为主,不存在信号肽和跨膜区域。此外,构建原核表达重组质粒pET30a-LmGSTU1,探究重组菌BL21 (pET30a-LmGSTU1)在不同浓度Cd胁迫下的生长变化。在400 mg/L Cd胁迫下,两种菌的生长速率差异最为显著,重组菌BL21 (pET30a-LmGSTU1)的生长速率高达对照菌BL21 (pET30a)的2倍,说明LmGSTU1基因的表达能增强大肠杆菌BL21对重金属Cd胁迫的耐受性。研究结果可为后续深入研究LmGSTU1基因在浮萍中的解毒机制奠定理论基础。Glutathione-S-transferases(GST) are multifunctional enzymes encoded by a large gene family,which plays an important role in plant tolerance to heavy metal stress.The LmGSTU1 gene was amplified using cadmium enriched duckweed cDNA as a template,and further bioinformatics analysis of the LmGSTU1 gene was performed.The results showed that the LmGSTU1 gene,with two subfamily domains of GST-C and GST-N,had a total length of 675 bp and encode 224 amino acids.The LmGSTU1 protein was an acidic hydrophilic protein with negative charge and stability,containing 14 phosphorylation sites.The secondary structure of LmGSTU1 protein was mainly α-helix,without signal peptides or transmembrane regions.In addition,the prokaryotic expression recombinant plasmid pET30a-LmGSTU1 was constructed to explore the growth of recombinant strain BL21(pET30a-LmGSTU1) under different concentrations of heavy metal Cd stress.The results showed that under the stress of 400 mg/L Cd,the growth rate difference between the two bacteria was most significant.The growth rate of recombinant strain BL21(pET30a-LmGSTU1) was twice that of the control strain BL21(pET30a).It indicated that the expression of LmGSTU1 gene can enhance the tolerance of Escherichia coli BL21 to heavy metal Cd stress.The results of this study can lay a theoretical foundation for subsequent in-depth research on the detoxification mechanism of LmGSTU1 gene in duckweed.

关 键 词：LmGSTU1基因 浮萍 原核表达 生物信息学分析 

分 类 号：Q78[生物学—分子生物学]