青花菜病程相关蛋白基因BoPR2的克隆与表达

Cloning and expression analysis of a pathogenesis-related protein gene BoPR2 from Brassica oleracea var. italica

病程相关蛋白基因以家族形式存在于植物中,在抗病反应中起着重要作用。以青花菜为试材,利用PCR法克隆到1个PR2基因,定名为BoPR2。测序结果表明,BoPR2基因组全长1188bp,具1个内含子,编码区全长1092bp,编码351个氨基酸;序列比对和系统发育分析结果显示,BoPR2与野甘蓝、甘蓝型油菜和白菜PR2的相似度最高,在发育树上聚为一组,与亚麻荠、荠菜的相似度最低,亲缘关系最远;实时定量PCR结果表明,BoPR2的表达受芸薹根肿菌诱导,在10d时的相对表达量最大,约为对照的6倍;但BoPR2的表达不受核盘菌的诱导。BoPR2基因的克隆与表达分析,为青花菜抗病机理研究及开展分子育种奠定了基础。

Pathogenesis-related protein genes comprise a gene family in plants,and they play a key role in disease resistance.In this study,a gene designated BoPR2 was isolated from broccoli material using the PCR method.Sequencing results indicated that the full-length genomic DNA was 1 188 bp with an intron,and its coding sequence was 1 092 bp encoding 351 amino acids.Sequence comparison and phylogenetic analysis results showed that higher similarities were found between BoPR2 and PR2 proteins from Brassica oleracea var.oleracea and B.rapa subsp.chinensis,and they were clustered into the same clade.The lowest similarities were seen between BoPR2 and PR2s from both Camelina sativa and Capsella rubella,indicating their distinct relationships.Real-time quantitative PCR results revealed that the expression of BoPR2 gene was induced by Plasmodiophora brassicae,and the highest relative expression level was detected at 10 d after incubation with an approximately 6-fold increase.However,the expression of BoPR2 was not affected by Sclerotinia sclerotiorum.Isolation and expression analysis of BoPR2 provide evidence for further studies on disease resistance mechanism and broccoli molecular breeding.