云南花生丛枝植原体secY基因序列分析及结构预测

SecY Gene Sequence Analysis and Structure Prediction of Peanut Witches′-broom Phytoplasma in Yunnan Province

对采自云南元谋的花生丛枝植株总DNA进行secY基因的巢式PCR扩增,得到约1 700 bp的特异扩增片段,将该扩增产物克隆后进行序列测定,表明该片段长1 709 bp,该序列包括部分rpl15基因、全部secY基因序列以及部分的map基因,为植原体部分spc核糖体蛋白操纵子,其中secY基因编码的蛋白包括420个氨基酸,为含有10个明显跨膜区的整合性跨膜蛋白。通过同源性比对及构建的系统进化树,表明该株系与来源于台湾、海南的花生丛枝植原体亲缘关系最近,确定了该株系属于16SrII-A亚组成员。该分类结果与基于16SrDNA及rp基因的分析结果一致。

A fragment about 1 700 bp of secY gene was amplified by nested-PCR from the total DNA of diseased peanut showing witches′-broom in Yuanmou County of Yunnan Province.After cloning and nucleotide sequencing analysis of amplified fragment indicated that the DNA fragment was 1 709 bp in length,which was the partial phytoplasmal spc ribosomal protein operon containing the rpl15 gene,a protein translocase gene(secY) and the map gene.The secY gene encoded a SecY protein of 420 amino acids and was an integrated transmembrane protein which has 10 evident transmembrane domains.From the homology comparison and the phylogenetic tree based on secY gene sequences showed that the genetic relationship of peanut witches′-broom phytoplasma strain from Yunnan Province(PnWB-YNym) was closely related with PnWB from Taiwan and Hainan Province and confirmed that PnWB-YNym belongs to the member of subgroup A,group 16SrII.The classification result based on secY gene analysis coincided with those of results based on 16SrDNA gene and rp gene.