表达多肽抗生素apidaecin的转基因烟草及其抗病性的初步分析

将多肽抗生素apidaecin基因与病程相关蛋白的信号肽序列融合，构建了apidaecin的分泌型植物表达载体、apidaecin与另一多肽抗生素Shiva\|I的双价分泌型植物表达载体，以本实验室原来构建的Shiva-I分泌型植物表达载体做对照，转化了模式植物烟草。对3种转基因植物进行了分子检测，转化再生苗95%为PCR阳性，Southern杂交结果进一步证明外源基因已经整合到了烟草基因组中，RT-PCR检测表明外源基因可以在转基因烟草内正常转录。对T0代转基因烟草进行烟草野火病的抗病性实验，从3种转基因烟草中都得到了抗病植株，病情指数分析的初步结果显示，双价转基因烟草抗病性最好，apidaecin的次之，Shiva-I的最差。

Construction of Plant Expression Vectors Harboring a Peptide Antibiotic-apidaecin Gene and Resistance Analysis of the Transgenic Tobacco

Two plant expression vectors(pBinPRHbI and pBinPRSIHbI)were constructed:Firstly,apidaecin gene were fused to the signal peptide coding sequencing of a PR-protein,and cloned into a binary vector pBin438 to form pBinPRHbI.Then,the cassette consisting of 35S promoter,PR signal peptide coding sequencing and apidaecin gene was cut off from pBinPRHbI and inserted into another plant expression vector pBinPRSI to produce a bivalent plant expression vector pBinPRSIHbI.pBinPRSI was constructed previously in our lab and contained PR signal peptide and Shiva-I fusion gene under control of 35S promoter.The three plant expression vecotrs were introduced into tobacco by \%Agrobacterium\%-mediated transformation.The positive rate of PCR was 95% in all putative transgenic plants.Results from Southern blot indicated that foreign genes were integrated into tobacco genome and RT-PCR analysis proved that the foreign gene was transcribed in transgenic tobacco.The transgenic tobacco showed higher resistance to \%P.syringae pv tabaci\%,the causal agent of tobacco wild fire disease,than their original cultivars.From the disease index,the transgenic plants carrying apidaecin and Shiva-I genes had highest resistance among three kinds of transgenic plants,and the plants carrying Shiva-I gene alone had lowest resistance.