绿豆果胶甲酯酶基因及其响应镉胁迫的分析  

Pectin Methylesterase Gene of Mung Bean and its Response to Cadmium Stress

作　　者：杨乐 张创娟 程斌 冷艳[1] 李师翁[1] YANG Le;ZHANG Chuang-juan;CHENG Bin;LENG Yan;LI Shi-weng(School of Biological and Pharmaceutical Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学生物与制药工程学院,兰州730070

出　　处：《兰州交通大学学报》2022年第4期119-127,共9页Journal of Lanzhou Jiaotong University

基　　金：国家自然科学基金(31760110)。

摘　　要：果胶甲酯酶(PME)是在植物细胞壁中起重要功能的酶,通过去甲酯化降低细胞间的约束,使细胞伸长.基于绿豆(Vigna radiata(Linn.) R. Wilczek)基因组注释文件,利用HMMER和Pfam等软件对绿豆果胶甲酯酶(PMEs)进行鉴定,分析PMEs基因结构和系统发育等.运用转录组和酶学方法检测正常条件和镉(Cd)胁迫下绿豆苗期根、茎和叶中PMEs表达模式及PME酶活性的变化.结果表明:绿豆基因组有80个PMEs,大部分PMEs具有相似的结构和共同的motif.系统发育分析将80个VrPMEs编码果胶甲酯酶蛋白(VrPMEs)归为5个分支,其与同科大豆GmPMEs具有更近的亲缘关系.17个VrPMEs在对照和Cd处理组绿豆苗期根、茎、叶中均有表达,但表达水平不同.Cd胁迫显著上调根中3个VrPMEs平均3.52倍,显著下调14个VrPMEs平均1.89倍;显著上调茎中2个VrPMEs平均2.69倍;对叶中VrPMEs表达影响较小.Cd胁迫在1、5和9天显著升高根中PME的平均酶活1.06、1.32和1.85倍,而对茎和叶中PME活性影响较小.基因表达与酶活性的结果相印证,强调根PME基因及其酶参与了绿豆幼苗期对Cd胁迫的响应,为进一步研究植物PME基因功能及其在重金属胁迫中的作用积累了重要资料.Pectin methyl esterase(PME)plays important roles in plant cell walls,reducing the intercellular constraints and promoting the cell elongation through demethylation.Based on the annotation files of mung bean genome,PME gene is identified by using HMMER and Pfam softwares,and the gene structure and phylogenetic is further analyzed.Furthermore,PME expression patterns and the activity of PME enzyme in root,stems,and leaves of mung bean seedlings treated with or without cadmium(Cd)were detected by using transcriptome and enzymology.The results showed that the mung bean genome contains a total of 80 PMEs,most of which have similar gene structure and common motifs.Phylogenetic analysis clustered the proteins,i.e.,pectin methyl esterase(VrPMEs),into five clades,which were more closely related to soybean GmPMEs.Transcriptome analysis showed that 17 VrPMEs were expressed in roots,stems,and leaves of mung bean seedlings in the control and Cd treatment groups,but the expression levels were different.Cd stress has significantly up-regulated three VrPMEs in roots by an average of 3.52 times,while has significantly down-regulated 14 VrPMEs by an average of 1.89 times;and has significantly up-regulated two VrPMEs in stems by an average of 2.69 times;and less affect them in leaves.Cd stress has increased the enzyme activity of PME in roots by an average 1.06,1.32,and 1.85 times at 1,5,and 9 days,respectively,but had less effect on the activity of stems and leaves.The results of gene expression and enzyme activity confirmed that PME genes and enzyme were involved in the response of mung bean seedlings to Cd stress,especially in the roots.Our results might provide important data for further study on the function of plant PME genes and their roles in heavy metal stress.

关 键 词：绿豆 果胶甲酯酶基因 镉胁迫 转录组 

分 类 号：S522[农业科学—作物学]