两种凝集素基因在转基因烟草中表达的研究

构建了含尾穗苋凝集素基因(ACA)的cDNA序列和改造后的雪花莲凝集素基因(GNA)的植物表达载体pBACG。在此表达载体中，ACA和GNA基因的表达分别由35S启动子和CoYMV启动子控制。通过农杆菌介导，将ACA和GNA基因转化到烟草中，经卡那霉素筛选获得60株转化再生植株。对PCR检测呈阳性的50株植株进行接蚜虫实验，结果表明，其平均抑虫率达83．9％。Southern blotting分析表明，ACA和GNA基因都已整合到烟草基因组中。Western blotting结果显示这两个基因在不同植株中都可表达其相应的蛋白质，但表达水平不同。部分Western blotting分析呈阳性植株的抗蚜性与T0代相近，达85．3％，说明这两个基因的抗蚜功能可以稳定遗传。

Expression of Two Plant Agglutinin Genes in Transgenic Tobacco Plants

A plant expression vector pBACG containing the DNA sequence coding for Amaranthus caudatus agglutinin (ACA) and a modified Glanthus nivalis agglutinin (GNA) gene was constructed.Leaf explants of Nicotiana tobacum cv.SRI were transformed with A.tumefaciens LBA4404 harbouring the above expression vector.Results from PCR and Southern blotting analysis showed that both the ACA and GNA gene were inserted into the genome of transformed tobacco plants.Western blottingting analysis of soluble protein isolated from transgenic plants showed that ACA and GNA were synthesized.The results from insect bioassay with peach aphids (Myzus persicae) revealed that the transgenic plants of pBACG had acquired high resistance against peach aphids.The average aphid-inhibition rate reached up to 83.9% and 85.3% for transgenic plants (T_0) and their selfed progenies (T_1) respectively,indicating that the functions of these two genes were inheritable.