HMA基因家族在芸薹属AC基因组中的进化分析

摘要

To better understand the metal ion transport mechanism in AC genomes of Brassica crops,we identified HMA (heavy metal transporting ATPase) genes in Brassica rapa,B.oleracea and B.napus genomes and analysed their evolution.Results showed that total of 50 candidate HMA genes were identified in AC genomes,including 14 in B.rapa genome,13 in B.oleracea genome,23 in B.napus genome (11 in A subgenome,12 in C subgenome).HMA genes were unevenly duplicated in the 3 species.50 HMA genes belonged to 3 subgroups (P_1 B-1,P_1 B-2 and P_1 B-4).Among the subgroups,conserved protein sequence distribution,protein properties,gene structure and the cis-acting elements in promoter region were all different.HMA genes were expressed differently in the same tissue of the same subgroup.8 HMA genes (including Bra003110,Bol030251,BnaA10g06240D,BnaC09g28870D,BnaC09g11230D,BnaC04g20290D,BnaA09g10950D and Bra027641) were significantly different from AtHMA5.It suggested that these genes might present new functions different from homologous gene AtHMA5 in Brassica crops.Besides,the new variant of GICCSME and GICCPSE in AC genomes was different from A.thaliana HMA genes site GICC (T/S) SE.It might have been associated with new function of the corresponding genes.The present results of the study would shed light on specific functional analysis of HMA genes in Brasscia AC genomes,and could also guide the study of metal ion transport mechanism by HMA genes in Brassica crop.%为研究芸薹属AC基因组重金属转运ATP酶(HMA,heavy metal transporting ATPase)参与的金属转运机制,利用白菜、甘蓝和甘蓝型油菜全基因组数据对HMA基因进行全基因组水平鉴定,并分析其在芸薹属AC基因组中的进化.结果显示,在芸薹属AC基因组中共鉴定到50个HMA基因,其中白菜14个、甘蓝13个、甘蓝型油菜23个(A亚基因组11个,C亚基因组12个),并且HMA基因在三个物种中均存在不均匀加倍的现象.这50个基因分属于P_1B-1、P_1B-2、P_1B-4三个亚族,在蛋白保守序列分布、蛋白理化性质、基因结构和启动区顺式作用元件等方面不同亚族之间各有差异,但同一亚族的基因在组织表达特异性方面也存在较大的差异.还发现Bra003110、Bol030251、BnaA10g06240D、BnaC09g28870D,BnaC09g11230D、BnaC04g20290D、BnaA09g10950D和Bra027641几个与AtHMA5同源的基因,在多个方面较AtHMA5发生了较大的变异,可能会导致这些基因在芸薹属作物中延伸出不同于AtHMA5的功能.在芸薹属AC基因组HMA基因中发现的GICCSME和GICCPSE新变异类型,不同于拟南芥中的GICC(T/S) SE功能位点,也可能导致相应的基因出现新的功能变异.本研究为从芸薹属AC基因组中选择特异性金属离子转运的HMA基因提供生物信息学参考,对进一步解析芸薹属植物中HMA基因参与的金属离子转运机制具有重要的指导意义.