摘要： 为揭示结缕草LEA蛋白在植物逆境胁迫应答过程中的作用与功能，利用RT-PCR方法从日本结缕草Meyer中克隆得到一个lea基因，命名为Zjlea3，对其进行生物信息学分析。蛋白质理化性质分析结果表明：该基因编码产物包含177个氨基酸，预测分子质量为18.3 ku，理论等电点（pI）为5.63，为亲水性蛋白，含有9个特征性的11氨基酸基序，属于LEA蛋白中的第3组成员。聚类分析结果表明：Zjlea3蛋白与高粱、石茅等耐高温物种的同源蛋白亲缘关系最近。荧光定量PCR分析显示：在低温、干旱和高盐胁迫下，Zjlea3基因表达量均有上调，表达量峰值分别出现在72，24，72 h，其中受低温诱导上调幅度最大。转基因酵母抗逆性分析显示：转化Zjlea3基因的酵母细胞对冷冻、高盐和高渗胁迫的耐受能力显著提升。由此推测Zjlea3蛋白参与结缕草抵御低温、干旱和高盐等非生物胁迫的调控。

关键词: LEA蛋白, 日本结缕草, 非生物胁迫, 表达模式, 抗逆功能

Abstract: To reveal the role and function of Zoysia japonica LEA protein in plant response to stress, a lea gene designated Zjlea3 from Zoysia japonica Meyer was cloned using RT-PCR. The bioinformatics analysis were performed on this gene.The results of protein physicochemical properties showed that the gene encoded a hydrophilic protein that contained 177 amino acids with a predicted molecular weight of 18.3 ku and a theoretical isoelectric point (pI) of 5.63. The protein belonged to the Group3 of the LEA family, containing 9 repeats of the 11-mer motif that characterized the group. The phylogenetic tree analysis indicated that the Zjlea3 was closely related to thehomologous protein from high temperature tolerance species such as Sorghum bicolo r and S. halepense. Fluorescence quantitative analysis showed that the expression of Zjlea3 gene was up-regulated under low temperature, drought and high salt stress, with the peak levels at 72, 24, 72 h, respectively, and with the greatest modulation under low temperature stress. The stress resistance analysis of transgenic yeast indicated that yeast cells harboring Zjlea3 had significantly increased tolerance to freezing,salty and hyperosmotic stress.It is speculated that Zjlea3 protein is involved in the regulation of Zoysia japonica against abiotic stresses such as low temperature, drought and high salt.

Key words: LEA protein, Zoysia japonica, Abiotic stress, Expression pattern, Stress resistance function

中图分类号: 

• Q943.2