桃果实PLDα基因的表达及生物信息学分析

Bioinformatics analysis and expression of PLDα gene in peach fruits

磷脂酶D(PLD)能催化磷酸二酯键水解和碱基交换,其水解产物磷脂酸可以作为第二信使,参与植物信号转导过程。几乎在植物所有的生命阶段及对环境胁迫的应答中,PLD都起着重要的作用。本试验借助分子生物学手段,在体外构建了p ET30a-PLDα重组表达载体,并成功地在表达菌株Transetta(DE3)中进行表达。研究发现PLDα蛋白氨基酸序列存在2个HKD基序,两基序间隔320个氨基酸,亲水性平衡系数为-0.417,表明PLDα蛋白为疏水性蛋白。系统进化树构建结果显示,桃果实PLDα蛋白与草莓PLDα蛋白二者亲缘关系最近;三维结构模拟存在的"洞穴"结构可以很好地解释该蛋白的疏水性。实时荧光定量PCR结果表明,低温能提高PLDα基因m RNA基因表达水平。

Phospholipase fl(PLD)can catalyze the hydrolysis and base exchange of phosphodiester bonds,its hydrolyzate phosphatidic acid(PA)can be used as a second messenger to participate in plant signal transduction processes.PLfl plays an important role in almost all stages of plant life and responses to environmental stress.In this study,the recombinant PLDa protein was expressed in Escherichia coli by molecular biolog^^method.There were two HKD motifs in PLDa protein,which were separated by320amino acids.The hydrophilic balance coefficient was-0.417,which indicated that PLDa protein was a hydrophobic protein.The results of phylogenetic tree revealed that PLDa protein of peach was more closely related to strawberry PLDa protein in evolution.The three-dimensional structure of peach PLDa protein showed a“cave”structure,this structure could explain the hydrophobicity of the protein.The results of qPCR showed that PLfla mRNA of peach fruit was induced in the low temperature.