Chen Hao, Zhang Guoan, Zhang Qifa, Lin Yongjun
National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070, China.
J Econ Entomol. 2008 Feb;101(1):182-9. doi: 10.1603/0022-0493(2008)101[182:eotbtr]2.0.co;2.
Ten transgenic Bacillus thuringiensis Bt rice, Oryza sativa L., lines with different Bt genes (two Cry1Ac lines, three Cry2A lines, and five Cry9C lines) derived from the same variety Minghui 63 were evaluated in both the laboratory and the field. Bioassays were conducted by using the first instars of two main rice lepidopteran insect species: yellow stem borer, Scirpophaga incertulas (Walker) and Asiatic rice borer, Chilo suppressalis (Walker). All transgenic lines exhibited high toxicity to these two rice borers. Field evaluation results also showed that all transgenic lines were highly insect resistant with both natural infestation and manual infestation of the neonate larvae of S. incertulas compared with the nontransformed Minghui63. Bt protein concentrations in leaves of 10 transgenic rice lines were estimated by the sandwich enzyme-linked immunosorbent assay. The cry9C gene had the highest expression level, next was cry2A gene, and the cry1Ac gene expressed at the lowest level. The feeding behavior of 7-d-old Asiatic rice borer to three classes of Bt transgenic rice lines also was detected by using rice culm cuttings. The results showed that 7-d-old larvae of Asiatic rice borer have the capacity to distinguish Bt and non-Bt culm cuttings and preferentially fed on non-Bt cuttings. When only Bt culm cuttings with three classes of different Bt proteins (CrylAc, Cry2A, and Cry9C) were fed, significant distribution difference of 7-d-old Asiatic rice borer in culm cuttings of different Bt proteins also was found. In the current study, we evaluate different Bt genes in the same rice variety in both the laboratory and the field, and also tested feeding behavior of rice insect to these Bt rice. These data are valuable for the further development of two-toxin Bt rice and establishment of appropriate insect resistance management in the future.
对源自同一品种明恢63的10个携带不同Bt基因的转基因苏云金芽孢杆菌（Bt）水稻品系（2个Cry1Ac品系、3个Cry2A品系和5个Cry9C品系）进行了实验室和田间评估。使用两种主要水稻鳞翅目昆虫物种的初龄幼虫进行生物测定：二化螟，Scirpophaga incertulas (Walker) 和三化螟，Chilo suppressalis (Walker)。所有转基因品系对这两种水稻螟虫均表现出高毒性。田间评估结果还表明，与未转化的明恢63相比，所有转基因品系在自然侵染和人工接种二化螟初孵幼虫的情况下均具有高抗虫性。通过夹心酶联免疫吸附测定法估计了10个转基因水稻品系叶片中的Bt蛋白浓度。cry9C基因表达水平最高，其次是cry2A基因，cry1Ac基因表达水平最低。还使用稻茎切段检测了7日龄三化螟对三类Bt转基因水稻品系的取食行为。结果表明，7日龄三化螟幼虫有能力区分Bt和非Bt稻茎切段，并优先取食非Bt切段。当仅投喂含有三类不同Bt蛋白（CrylAc、Cry2A和Cry9C）的Bt稻茎切段时，也发现7日龄三化螟在不同Bt蛋白的稻茎切段中有显著的分布差异。在本研究中，我们在实验室和田间评估了同一水稻品种中的不同Bt基因，并测试了水稻害虫对这些Bt水稻的取食行为。这些数据对于未来双毒素Bt水稻的进一步开发和建立适当的抗虫管理具有重要价值。
