摘要： 为探讨大豆GmbHLH041转录因子在应答镉胁迫中的作用，根据前期的镉胁迫前后大豆根系转录组测序结果，筛选获得响应Cd胁迫的GmbHLH041基因，利用NCBI和Phytozome数据库，结合生物信息学软件对GmbHLH041基因进行预测分析，并通过qRT-PCR的方法检测大豆根系中GmbHLH041基因在50 μmol/L CdSO₄胁迫0，24 h的表达情况。结果显示，GmbHLH041基因编码542个氨基酸，相对分子质量为61.17 ku，理论等电点为5.89。二级结构预测结果显示，该氨基酸序列主要以无规则卷曲（39.48%）、α-螺旋（37.27%）和伸展链（16.61%）的形式存在，从拟南芥bHLH家族中的12个亚家族中挑选了24个bHLH蛋白并结合其他物种中亲缘关系较近的bHLH蛋白，对GmbHLH041进行系统进化树分析发现，GmbHLH041与野生大豆和狭叶羽扇豆的bHLH041蛋白亲缘关系较近，GmbHLH041划分到拟南芥bHLH家族第4亚族Ⅳd中。根据进化树的分析结果，选取与GmbHLH041亲缘关系最近的GsbHLH041、LabHLH041以及拟南芥第4亚族Ⅳd中的AT5G56960进行多重比对，结果显示，GmbHLH041含有一个保守的bHLH结构域；荧光定量PCR结果显示，GmbHLH041基因在50 μmol/L CdSO₄胁迫24 h后表达量极显著上升，说明GmbHLH041基因在Cd胁迫应答中可能发挥着重要的作用。

关键词: 大豆, 镉, bHLH

Abstract: In order to investigate the roles of GmbHLH041 in soybean response to cadmium stress, GmbHLH041 was chosen based on the primary transcriptome sequencing of soybean roots after cadmium treatment. By using NCBI,phytozome database combined with bioinformatics software,the systematic prediction and analysis of GmbHLH041 were conducted,and by qRT-PCR,the expression of GmbHLH041 in soybean roots was investigated after 50 μmol/L CdSO₄ treatment for 0 and 24 h. GmbHLH041 existed mainly in Random coil(39.48%),Alpha helix(37.27%)and Extended strand(16.61%)according to the secondary structure prediction. The results showed that GmbHLH041 encoded 542 amino acids,the relative molecular weight was 61.17 ku and the theoretical pI was 5.89. Phylogenetic analysis of GmbHLH041 was conduncted with 24 bHLH protein from 12 subgroup of bHLH family in Arabidopsis thaliana and other closely related bHLH proteins of other species. The results of phylogenetic analysis showed that the GmbHLH041 protein had a close homologous relationship with GsbHLH041 and LabHLH041 and belonged to the subclass Ⅳd of Arabidopsis thaliana bHLH proteins. Acording to the results of phylogenetic analysis,alignment of GmbHLH041 with closely related GsbHLH041,LabHLH041 and AT5G56960 from the bHLH subclass Ⅳd of Arabidopsis thaliana,the results showed that GmbHLH041 had a conserved bHLH domain. The expression of GmbHLH041 was up-regulated significantly after 50 μmol/L CdSO₄ treatment for 24 h,indicating its important function in response to cadmium stress.

Key words: Soybean, Cadmium, bHLH

中图分类号: 

• Q78

• S565.01