一个新的油菜NHX基因电子克隆及序列分析

基于电子克隆的方法,从甘蓝型油菜中获得一个新的反向转运蛋白基因cDNA序列,暂被命名为BnNHX6。BnNHX6包含一个完整的长为1593bp的开放阅读框架,编码530个氨基酸。BnNHX6蛋白属于跨膜蛋白,有9个跨膜区,含有信号肽,预测在质膜上。通过同源比对和进化分析发现,BnNHX6的氨基酸序列与拟南芥AtNHX5和AtNHX6、西红柿LeNHX2、毛白杨PtNHX2基因所编码的氨基酸序列高度同源,同源性分别为78.4%、92.6%、77.1%、76.9%,亲缘关系较近;但与已报道的油菜BnNHX1同源性仅为24.9%,亲缘关系很远,表明BnNHX6是一个新的油菜反向转运蛋白基因。

Electronic cloning and sequence analysis of a novel Na+/H+ antiporter gene BnNHX6 from Brassica napus

A novel Na＋/H＋antiporter（NHX） gene was isolated from Brassica napus through electronic cloning.The gene was tentatively designated as BnNHX6,whose open reading flame was 1593 bp in length and encoded 530 amino acids.BnNHX6 possessed nine membrane-spanning segment domains and signal peptide sequences and was predicted to locate in plasma membrane.Multiple alignment analysis based on the amino acids encoded by different NHX genes from Arabidopsis thaliana,Solanum lycopersicum and Populus tomentosa indicated that BnNHX6 showed high similarity with 78.4%,92.6%,77.1% and 76.9% identities to AtNHX5,AtNHX6,LeNHX2 and PtNHX2,respectively.However,with 24.9% identities to BnNHX1 previously reported from Brassica napus,the evolutionary analysis showed that BnNHX6 was most closely related to AtNHX5,AtNHX6,LeNHX2 and PtNHX2,respectively,and was very far related to BnNHX1.Those resulted suggested that BnNHX6 was a novel Na ＋ /H ＋ antiporter gene in rapeseed.