甘蓝型油菜HIPPs基因家族的鉴定与表达分析

Identification and Expression Analysis of HIPPs Gene Family in Brassica napus L.

重金属相关异戊二烯化植物蛋白(HIPPs,heavy metal-associated isoprenylated plant proteins)是金属离子在植物细胞内安全运输的关键蛋白,在植物体金属离子稳态的维持过程中发挥重要作用。目前关于HIPPs基因家族的研究多集中于模式植物水稻(Oryza sativa L.)和拟南芥(Arabidopsis thaliana (L.) Heynh.),在甘蓝型油菜(Brassica napus L.)中报道相对较少。本研究通过生物信息学的方法在甘蓝型油菜全基因组(Darmor-bzh v10)中鉴定到了不均匀分布在19条染色体上的104个BnaHIPPs基因。蛋白理化性质分析发现其氨基酸数目在120~630 aa,蛋白分子量在13827.56~64467.05 ku,平均等电点为8.07,蛋白平均疏水指数在-1.146~-0.17之间。基因表达模式分析发现它们在不同组织和发育时期的表达模式具有一定的时空表达特性,在根中的表达量最高。镉胁迫处理条件下BnaHIPPs的表达模式发生了改变,BnaA08p24150、BnaA09p41730和BnaC06p45180在根和叶片中的相对表达水平都发生了上调。系统进化关系显示BnaHIPPs基因被分为5个亚家族。此外,共线性分析显示在BnaHIPPs基因的进化过程中,大多数的BnaHIPPs都是以片段复制的形式参与BnaHIPPs基因家族的扩张过程,仅发现BnaC05p3800、BnaC05p3810、BnaC05p3820和BnaC05p3830以串联重复的形式参与BnaHIPPs的复制事件。本研究结果将为甘蓝型油菜BnaHIPPs基因家族的进一步研究奠定基础。

The heavy metal-associated isoprenylated plant proteins(HIPPs),which play an important role in the maintenance of metal ion homeostasis and detoxification mechanism,have been accepted as key proteins in the safety transportation of metallic ions in plants.While the HIPPs gene family has been investigated in these model plants,such as Oryza sativa L.and Arabidopsis thaliana(L.)Heynh.,to our knowledge the HIPPs gene family in Brassica napus L.remains analyzed.In this study,104 HIPPs genes were identified in the genome of Brassica napus L.(Darmor-bzh v10)using Bioinformatics methods.The HIPPs members were not evenly distributed on 19 chromosomes.The amino acid number,protein molecular weight,isoelectric point,and protein hydrophobicity index of BnaHIPPs were ranged from 120 to 630 aa,13827.56 to 64467.05 ku,8.07,and-1.146 to-0.17,respectively.The HIPPs genes showed tissue specific expression and temporal specificity,as well as the highest transcripts in roots.Moreover,the expression of BnaHIPPs was significantly altered in response to Cd2+stress treatment.For example,BnaA08p24150,BnaA09p41730 and BnaC06p45180 were up-regulated in both roots and leaves.The phylogenetic analysis showed that BnaHIPPs were divided into five distinct clades.The collinearity analysis elucidated that the expansion of the BnaHIPPs gene family members was largely contributed by fragment replication,and only for four members BnaC05p3800,BnaC05p3810,BnaC05p3820,and BnaC05p3830 were found with tandem repetition.Our results will provided insights for future deciphering the BnaHIPPs gene family members in B.napus L..