【摘要】 该研究在转录组数据基础上,以独行菜(Lepidium apetalum Willd.)种子耐受和不能耐受低温萌发的2组样本为材料,对其bHLH转录因子家族成员进行分析,并对该家族成员表达差异极显著的laICE1基因进行克隆、序列分析、结构预测,以探讨独行菜幼苗中laICE1基因表达对低温胁迫的响应特征。结果表明:(1)萌发中的独行菜种子,至少有83个bHLH转录因子序列表达,相对于低温萌发停滞组,在低温萌发耐受组的独行菜种子中,有10个下调、13个上调、60个表达差异不显著。其中表达量极显著下调的序列c20009_g1具有1 503bp开放阅读框,GO注释到ICE1基因,该基因命名为laICE1。(2)laICE1基因编码500aa,蛋白分子量为54 635.19kD,理论等电点为5.45,分子式为C2364H3742N688O758S22;该蛋白具有保守结构域bHLH。(3)定量分析表明,laICE1基因在非低温胁迫的独行菜种子中的表达量显著低于一直处于低温胁迫中不能进行萌发的独行菜种子,这与转录组数据库中该序列表达情况一致;而laICE1基因在独行菜幼苗期经低温处理后,其表达量显著上调,表明laICE1基因可能在独行菜幼苗耐受低温生长中具有一定的作用。更多还原

【Abstract】 On the basis of transcriptome data,the expression of bHLHs of Lepidium apetalumseeds which can tolerate low temperature germination and not between the two groups,were compared,and the family of class bHLH transcription factors in the seeds transcriptome is analyzed in this paper,the laICE1 was one of the bHLH transcription factor gene family members whose relative level of expression in seeds was different between the two-groups significantly.The gene was cloned and its expression was analyzed in response to low temperature stress in L.apetalum seedling.The results showed that:(1)there were 83 family members of bHLH transcription factors in L.apetalumseeds at least.Compared with the low temperature germination stagnation group,there were 17 down regulation,13 up regulation and 60 bHLHtranscription factors with no significant difference in the low temperature germination tolerance group seeds.Among them,the expression of c20009_g1 was down regulated remarkably,and it had an open reading frame composed of 1 503 bp.The sequence was annotated in the GO database with known plant cold related ICE1 genes.C20009_g1 was named laICE1 in this article.(2)Sequence analysis showed that laICE1 encodes a protein consisting of 500 aa with a molecular weight of 54 635.19 kD,a theoretical PI of 5.45,a formula of C2364 H3742 N688 O758 S22,and a conserved domain bHLH.(3)Quantitative analysis by real-time fluorescence showed that the expression of laICE1 was significantly lower in the seeds of the germination tolerance group than that in the seeds of the germination stagnation group.This is consistent with the data of the transcriptome.After low temperature treatment,the expression level of the gene was increased significantly in seedling stage.These results suggest that laICE1 may be related to the ability of the L.apetalumseedlings to tolerate low temperature.更多还原