中文摘要：

根据植物偏好性密码子进行改造获得了天蚕素B基因,又通过同尾酶连接获得2个和3个天蚕素B基因的串联体,分别构建植物表达载体,并采用农杆菌介导的方法转化紫花苜蓿。对转基因植物进行分子生物学检测,结果表明CB、CB2、CB3三个基因成功整合到了苜蓿基因组中,转基因植物总蛋白活性检测表明转CB、CB2、CB3基因的蛋白均有一定的抑菌活性,但串联CB3基因的抑菌活性最强。

英文摘要：

Cecropin B gene was designed and synthesized by plant preference codon,tandem two and three genes（CB2and CB3）were obtained by the tail enzyme.The plant expression vector containing these three genes were constructed respectively.Then,transformed them into alfalfa,by agrobacterium.Integration of the CB multimers gene into the alfalfa genome was confirmed by molecular identification.The total protein of transgenic alfalfa were extracted to detect its bacterial activation,in vivo studies of the protein from the transgenic alfalfa plant demonstrated significant resistance to bacterial wilt and bacterial spot,but bioactivity of the CB-multimers of three genes was higher than bioactivity of single CB.