Fujimoto H, Itoh K, Yamamoto M, Kyozuka J, Shimamoto K
Plantech Research Institute, Yokohama, Japan.
Biotechnology (N Y). 1993 Oct;11(10):1151-5. doi: 10.1038/nbt1093-1151.
As a first step towards development of insect resistant rice we have introduced a truncated delta-endotoxin gene, cryIA(b) of Bacillus thuringiensis (B.t.) which has specific biological activity against lepidopteran insects into a japonica rice. To highly express the cryIA(b) gene in rice the coding sequence was extensively modified based on the codon usage of rice genes. Transgenic plants efficiently expressed the modified cryIA(b) gene at both mRNA and protein levels. Bioassays using R2 generation plants with two major rice insect pests, striped stemborer (Chilo suppressalis) and leaffolder (Cnaphalocrosis medinalis), indicated that transgenic rice plants expressing the CryIA(b) protein are more resistant to these pests than untransformed control plants. Our results suggest that the B.t. endotoxin genes will be useful for the rational development of new rice varieties resistant to major insect pests.
作为培育抗虫水稻的第一步，我们已将苏云金芽孢杆菌（B.t.）的截短型δ-内毒素基因cryIA(b)导入粳稻中，该基因对鳞翅目昆虫具有特定生物活性。为了在水稻中高效表达cryIA(b)基因，根据水稻基因的密码子使用情况对编码序列进行了广泛修饰。转基因植物在mRNA和蛋白质水平上均高效表达了修饰后的cryIA(b)基因。使用R2代植株对两种主要水稻害虫——二化螟（Chilo suppressalis）和稻纵卷叶螟（Cnaphalocrosis medinalis）进行的生物测定表明，表达CryIA(b)蛋白的转基因水稻植株比未转化的对照植株对这些害虫具有更强的抗性。我们的结果表明，B.t.内毒素基因将有助于合理培育抗主要害虫的新型水稻品种。
