芒果细菌性黑斑病病菌抗铜基因copA克隆与序列分析

Cloning and sequence analysis of copA from Xanthomonas campestris pv.mangiferaeindicae

芒果细菌性黑斑病是由野油菜黄单胞菌芒果致病变种(Xanthomonas campestris pv.mangiferaeindicae)引起的细菌性病害,是芒果生产中最为重要的病害之一。本试验通过对比已报道的黄单胞属的抗铜基因copA序列的分析、比较,设计简并引物Copa-F/Copa-R,采用同源克隆法从芒果细菌性黑斑病病菌中扩增出约1 800 bp的DNA片段。序列分析表明,该基因片段含有1个完整的copA同源基因(GenBank accession No.KJ890405.1),其核苷酸序列全长1 794 bp,编码597个氨基酸,其分子量约66.271 kDa,等电点(PI)为6.40。系统进化树结果显示,该基因编码的氨基酸序列与Xanthomonas属多个不同种的抗铜基因聚为一类。

Mango bacterial black spot,causes by Xanthomonas campestris pv.mangiferaeindicae,is one of the most important diseases in mango production.In this study,degenerate PCR primers CopaF/CopaR were designed according to the conserved amino acid sequence of copA homologs from Xanthomonas spp.,and a DNA fragment about 1.8 kb was cloned from X.campestris pv.mangiferaeindicae.Sequence analysis showed that the DNA fragment was 1 794 bp,containing a complete copA homologue（GenBank accession No.KJ890405.1）,and encoding a putative protein of 597 amino acids with a molecular weight of 66.271 kDa and isoelectric point of 6.40.Phylogenetic analysis indicated that putative protein of CopA showed high similarity to CopA homologs of other Xanthomonas spp.Cloning of copA will be benefit to further study of the copper-resistance mechanisms of X.campestris pv.mangiferaeindica.