Abstract: In order to explore the functions of the senescence-related gene (SRG1) in Kalanchoe daigremontiana,the gene of KdSRG1 was cloned from the wild-type K daigremontiana,and then analyzed for its bioinformatics,subcellular localization,and gene expression analysis. The results showed that the open reading frame of KdSRG1 was 219 bp in length,encoding a peptide of 72 amino acids. The KdSRG1 protein is a hydrophilic unstable acidic protein,which was localized in the nucleus and the cell membrane,and had no transmembrane structures or signal peptides and species specific in property. The relative expression of KdSRG1 gene in K. daigremontiana was higher in its plantlets and leave than that in the roots and stems,which demonstrated that gene may be involved in the regulation of adventitious bud and leaf growth. By analyzing the cis-acting elements of KdSRG1 promoter,it was speculated that KdSRG1 gene would take a role in that plant meristem formation and palisade mesophyll cells differentiation,and the expression of this gene may be regulated by light signal,abscisic acid (ABA),and methyl jasmonate (MeJA). Moreover,the KdSRG1 gene may play a role in that plant stress regulation. The self-activation detection showed that KdSRG1 protein had no self-activation activity and could be used to the subsequent yeast two-hybrid experiments. This study could be used for further research on the functional mechanisms of KdSRG1 gene.

Key words: Kalanchoe daigremontiana, KdSRG1 gene, Gene cloning, Subcellular localization, Expression analysis

摘要： 为探究大叶落地生根(Kalanchoe daigremontiana)中衰老相关基因1(Senescence-related gene 1,SRG1)的功能,以野生型大叶落地生根为材料,克隆KdSRG1基因,对其进行生物信息学分析、亚细胞定位和基因表达分析。结果表明:KdSRG1基因开放阅读框为219 bp,编码72个氨基酸;KdSRG1蛋白是一个亲水性的不稳定酸性蛋白,定位于细胞核和细胞质,不含跨膜结构和信号肽,并且具有物种上的特异性;该基因在大叶落地生根的不定芽和叶中的相对表达量较高,说明其参与不定芽和叶的生长调控;通过分析其启动子顺式作用元件,推测KdSRG1基因参与植物分生组织表达和栅栏细胞分化过程,并且其表达可能受光信号、脱落酸(Abscisic acid,ABA)和茉莉酸甲酯(Methyl jasmonate,MeJA)调控,同时可能在植物逆境胁迫调控方面发挥作用;自激活检测表明KdSRG1蛋白没有自激活活性,可用于后续的酵母双杂实验。本研究为进一步研究KdSRG1基因的作用机制及功能奠定了基础。

关键词: 大叶落地生根, KdSRG1基因, 基因克隆, 亚细胞定位, 表达分析