苦荞麦FtNHX1基因的克隆及表达分析

为深入研究液泡膜Na~+/H~+逆向转运蛋白在植物耐盐中的作用,以耐盐苦荞麦品种川荞1号为材料,利用同源克隆方法得到NHX基因,命名为FtNHX1,并在Gen Bank中注册,登录号为KY438929;序列分析表明,该基因开放阅读框1 662 bp,共编码553个氨基酸,预测蛋白分子量61.24 kDa,等电点5.15。系统进化树分析表明,FtNHX1与拟南芥(AtNHX1)、水稻(OsNHX1)和小麦(TaNHX1)的亲缘关系较近,氨基酸同源率分别为60.22%,58.95%和57.30%;荧光定量PCR分析表明,随着Na Cl胁迫浓度的增加,FtNHX1基因在苦荞麦根部、茎基部和叶片的相对表达量极显著增加,150 mmol/L NaCl胁迫下增加幅度最大,分别比对照增加了254.10%,311.35%和256.18%;Na Cl胁迫下FtNHX1基因在苦荞麦根部、茎基部和叶片的平均表达量分别比对照增加了109.46%,145.67%和155.94%,茎基部和叶片的平均表达量较高,说明苦荞麦FtNHX1基因的表达明显受盐胁迫诱导和调节,FtNHX1基因与苦荞麦的耐盐性有密切联系。

Cloning and Expression Analysis of FtNHX1 in Tartary Buckwheat

In order to further study the Na+/H+ antiporter roles of vacuole membrane in salt tolerance of plants,the salt-tolerant tartary buckwheat variety Chuanqiao No.1 was used as materials,and the NHX gene was obtained by homology cloning,which named FtNHX1,and registered in GenBank,the landing number was KY438929.Sequence analysis showed that the open reading frame of FtNHX1 was 1 662 bp,encoding 553 amino acids,with predicted molecular weight of 61.24 kDa and isoelectric point of 5.15.Phylogenetic tree analysis showed that FtNHX1 was closely related to AtNHX1,OsNHX1 and TaNHX1,with 60.22%,58.95% and 57.30% amino acid homology rates.Quantitative real-time PCR analysis showed that the relative expression of FtNHX1 gene in roots,stem base and leaf of tartary buckwheat was significantly increased with the concentration increasing of NaCl stress,and that increased the most under NaCl stress of 150 mmol/L,which was increased by 254.10%,311.35% and 256.18% respectively in contrast with control.The average expression of FtNHX1 gene in roots and stem base and leaf of tartary buckwheat was increased by 109.46%,145.67% and 155.94% in contrast with control under NaCl stress,and that in stem base and leaf was very higher,indicating that the expression of FtNHX1 gene in tartary buckwheat was obviously induced and regulated by salt stress,and there was a close relationship between the FtNHX1 gene and the salt tolerance of tartary buckwheat.