甘蔗、斑茅及割手密Ⅲ型过氧化物酶基因克隆及比较分析

Isolation and Comparative Analysis of Class Ⅲ Peroxidases Gene DNA on Saccharum officinarum,Saccharum spontaneum and Saccharum arundinaceum

研究旨在通过比较分析甘蔗及其近缘种割手密和斑茅Ⅲ型过氧化物酶(Prxs)基因差异,探讨这三种植物Prxs功能差异的遗传基础。采用同源克隆方法,成功克隆获得了甘蔗、斑茅和割手密的Prxs基因DNA序列(Genebank登录号分别为KJ001797,KJ001798和KJ001799)。经测序鉴定,克隆获得的这三个基因DNA长度分别为3 030 bp、3 048 bp和3 028 bp,外显子长度均为1 083 bp,其中编码区长度为996 bp,编码331个氨基酸。蛋白质保守结构域分析表明,此三个基因均具有过氧化物酶典型保守结构域,属于依赖于亚铁血红素Ⅲ型过氧化物酶亚类,为目标基因,且在功能位点区域高度保守,只存在一个氨基酸位点差异。基因结构比较分析表明,克隆获得的割手密、斑茅和甘蔗过氧化物酶基因均包含4个外显子,与高粱、玉米和水稻的同源基因外显子个数一致,外显子长度有较小差异,而内含子长度却存在较大差异。高粱、玉米和水稻Prxs同源基因均处在靠近染色体末端的位置,说明此基因存在一定的同线性。本研究结果为深入研究Prxs基因在不同植物中功能差异提供了一定的参考,为研究植物中Prxs基因的进化规律奠定了一定的基础。

In this study,to isolate and comparate of class Ⅲ peroxidases(Prxs) gene DNA on Saccharum officinarum,Saccharum spontaneum and Saccharum arundinaceum,and investigate the functional differences of Prxs gene on sugarcane and relative species,by using the homologous cloning strategy,a Sorghum bicolor Prxs gene was used as probe,three novel Prxs genes(KJ001797,KJ001798 and KJ001799) were cloned.The sequencing data were showed,the length of these cloned gene was 3 030,3 048 and 3 028 base pair,respectively,each of the three genetic exon full length was 1 083 bp,including 5' untranslated regions 27 bp,3' untranslated regions 60 bp,and996 bp ORF,which coded 331 amino acids.The proteins conservative structural domain analysis were showed,these three genic proteins had typical well-conserved amino-acid residues of peroxidases,were classified to heme containing class Ⅲ peroxidases,which were the aimed genes,and the functional sites were highly conserved,only an amino acid site was different.The genic structural analysis were showed,each of the cloned gene was included four exons,was the same in sorghum,maize and rice,the exons length were nearly the same between these species,but the introns length were obviously different.The homologous genes of these clones were located on chromosomal terminal in sorghum,maize and rice,indicated that these homologous genes were collinear.This study provided a reference for further study in distinguishing the functional difference among different plants,lay a foundation for the evolution research of Prxs genes in plant kingdom.