Shi Xiao-Li, Yang Yi-Zhong, Cai Jian-Hua, Zhang Xiao-Li, Shi Min-Juan
School of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, Jiangsu, China.
Ying Yong Sheng Tai Xue Bao. 2009 Nov;20(11):2773-7.
Taking the insect-resistant transgenic corn varieties G03-2396 and G03-2739 and the conventional corn variety Suyu 16 as test materials, a bioassay in laboratory was conducted to test their resistance against Ostrinia furnacalis. The Bt toxin expression in different tissues of the two transgenic corns, the ingestion of Bt toxin by the 3rd and 5th instar of O. furnacalis, and the Bt toxin amount in feces of O. furnacalis larvae fed with Bt corns were analyzed by using enzyme-linked-immunosorbent-assay (ELISA). It was found that the central leaves of both G03-2396 and G03-2739 had great toxicity to O. furnacalis larvae. After fed with the central leaves for 6 d, the survival rate of neonate larvae was less than 3%, and that of the 3rd instar larvae was less than 70%. Female ears had smaller toxicity than central leaves. The Bt toxic protein was detected both in the leaves and in the female ears of the two transgenic corns, but its content was higher in central leaves than in female ears. The Bt toxic protein expression level was in order of G03-2739 central leaf (39.6 microg x g(-1) FM) > G03-2396 central leaf (26.1 microg x g(-1) FM) > G03-2396 female ear (17.0 microg x g(-1) FM) > G03-2739 female ear (14.6 microg x g(-1) FM). When fed with central leaf or female ear, the Bt toxic protein amount in the 3rd instar larvae was significantly higher than that in the 5th instar larvae. For the same age instar larvae, the Bt toxic protein content was significantly higher after fed with central leaf than fed with female ear, so did the Bt toxic protein content in larvae feces, being the highest (10.4 microg x g(-1) FM) for the 5th instar larvae fed with G03-2739 central leaf, and the lowest (2.7 microg x g(-1) FM) for the 3rd instar larvae fed with G03-2739 female ear.
以抗虫转基因玉米品种G03 - 2396和G03 - 2739以及常规玉米品种苏玉16为试验材料，在实验室进行生物测定以检测它们对亚洲玉米螟的抗性。采用酶联免疫吸附测定法（ELISA）分析了两种转基因玉米不同组织中的Bt毒素表达、亚洲玉米螟3龄和5龄幼虫对Bt毒素的摄取量以及取食Bt玉米的亚洲玉米螟幼虫粪便中的Bt毒素含量。结果发现，G03 - 2396和G03 - 2739的中部叶片对亚洲玉米螟幼虫均具有很强的毒性。用中部叶片饲喂6天后，初孵幼虫的存活率低于3%，3龄幼虫的存活率低于70%。雌穗的毒性小于中部叶片。在两种转基因玉米的叶片和雌穗中均检测到了Bt毒蛋白，但其含量在中部叶片中高于雌穗。Bt毒蛋白表达水平顺序为：G03 - 2739中部叶片（39.6μg×g⁻¹鲜重）＞G03 - 2396中部叶片（26.1μg×g⁻¹鲜重）＞G03 - 2396雌穗（17.0μg×g⁻¹鲜重）＞G03 - 2739雌穗（14.6μg×g⁻¹鲜重）。用中部叶片或雌穗饲喂时，3龄幼虫体内的Bt毒蛋白量显著高于5龄幼虫。对于相同龄期的幼虫，用中部叶片饲喂后体内的Bt毒蛋白含量显著高于用雌穗饲喂，幼虫粪便中的Bt毒蛋白含量也是如此，其中取食G03 - 2739中部叶片的5龄幼虫粪便中Bt毒蛋白含量最高（10.4μg×g⁻¹鲜重），取食G03 - 2739雌穗的3龄幼虫粪便中Bt毒蛋白含量最低（2.7μg×g⁻¹鲜重）。
