大豆GmNHX1基因克隆及其在酵母中的耐盐性分析  

Cloning and functional characterization of a vacuolar Na^+/H^+ antiporter gene (GmNHX1) from soybean

作　　者：范龙[1] 孙天杰[1] 杨郡[1] 张洁[1] 王冬梅[1] 

机构地区：[1]河北农业大学生命科学学院/植物逆境实验室,河北保定071001

出　　处：《河北农业大学学报》2015年第6期7-12,24,共7页Journal of Hebei Agricultural University

基　　金：转基因生物新品种培育重大专项子课题(2014ZX0800402B-001)

摘　　要：Na^+/H^+逆向转运蛋白基因在植物响应盐胁迫中具有重要作用。本研究从耐盐大豆品种‘冀豆7号'克隆Na+/H+逆向转运蛋白基因GmNHX1,并利用酵母突变体对该基因的功能进行了初步研究。结果发现,GmNHX1包含1 641 bp的开放阅读框,编码546个氨基酸,有典型的Na^+/H^+逆向转运蛋白特征,与已知功能的液泡膜Na^+/H^+逆向转运蛋白具有较高同源性。半定量分析结果表明,GmNHX1受盐胁迫上调表达,在相同浓度盐胁迫下该基因在叶片中的表达量高于根系;耐盐品种‘冀豆7号'在200 mmol/L NaCl胁迫下,其GmNHX1的表达相较0 mmol/L NaCl处理下的表达增加了225%,而盐敏感品种‘冀豆17'只增加了94%。利用nhx1盐敏感酵母突变体进行功能互补试验,结果发现在50,200 mmol/L NaCl胁迫条件下,转GmNHX1酵母突变体菌株生长速度高于对照,GmNHX1具有恢复nhx1酵母突变体耐盐性的功能。Na＋/H＋ antiporters play significant roles in plant responses to salinity stress. The full-length cDNA of Na＋/H＋ antiporter gene GmNHX1 was cloned from soybean cultivar ＇Jidou 7＇ , and its function was studied by using functional yeast complementation. The GmN- HX1 sequence contains 1 641 bp open reading frame encoding 546 amino acids, with a typical Na＋/H＋ antiporter feature. And it has high homology with vacuolar Na＋/H＋ antiporter of known function. The RT-PCR results show that the expression of GmNHX1 upregulated by salinity stress; the expression level in leaves is higher than that in root under the same NaCl treatment condition; Strong salt tolerant soybean cultivar Jidou7 under 200 mmol/L NaCl treatment, the expression of GmNHX1 increased by 225 % than without NaC1. While in weak salt tolerant soybean cultivar Jidoul7 only increased by 94%. To further investigate the role of GmNHX1 response to salt stress, salt sensitive yeast mutant YDR456W and AXT3 were used to functional complementation. Under 50 or 200 mmol/L NaC1 treatmenst, expression of GmNHX1 in YDR456W and AXTa mutants survived, suggesting that GmNHX1 comple- ments the salt-sensitive phenotype caused by NHXl gene disruption in yeast.

关 键 词：NA+/H+逆向转运蛋白 大豆 耐盐性 酵母突变体 

分 类 号：S565.1[农业科学—作物学]