人参Defensin基因表达载体构建及对锈病抗性分析

Construction of Expression Vector of Ginseng Defensin Gene and Analysis of Its Resistance against Rust

通过人参Defensin基因在拟南芥中的过表达,研究其在人参锈病菌胁迫过程中的抗性作用。采用RT-PCR技术克隆人参Defensin基因,其全长为240 bp,编码80个氨基酸,预测其蛋白分子量为12.091 1 ku。通过农杆菌介导浸花法将人参Defensin基因转到拟南芥中,经过抗性筛选及分子鉴定获得转基因拟南芥。以野生型拟南芥作对照,分析植株对锈病菌的抗性作用。结果表明:经锈病菌胁迫5 d,转基因拟南芥的生长状态明显优于野生型拟南芥,Defensin基因在转基因拟南芥中的表达量极显著高于野生型对照。人参Defensin基因对人参锈病菌具有一定的抗性作用。

Ginseng defensin genes play an important role in plant response to adversity stress. In this study, we focused on its resistance effect in the process of ginseng rust stress by construction of overexpression in Arabidopsis thaliana. Ginseng defensin gene was cloned by RT-PCR, the length of which was 240 bp, encoding 80 amino acids, and the predicted protein molecular weight was 12. 091 1 ku.Ginseng defensin gene was transformed into Arabidopsis thaliana using Agrobacterium tumefaciens strain harboring pCAMBIA1303-defensinby floral dip method. Then the transgenic plants were verified by resistance screening and genetic identification. At last, the resistance effect of the plants on the rust fungus was analyzed in comparison with the wild-type Arabidopsis. After rust stress for 5 d, the growth of transgenie Arabidopsis was observed to be obviously better than that of the wild, and the defensin gene expression in transgenic Arabidopsis thaliana was significantly higher in the meanwhile. These results show that ginseng defensin genes have certain resistance effect on ginseng rust fungus.