Zhejiang Academy of Agricultural Science, Institute of Crops and Nuclear Technology Utilisation, Hangzhou, China.
Pest Manag Sci. 2013 Jan;69(1):135-41. doi: 10.1002/ps.3379. Epub 2012 Aug 24.
Rice is the major food resource for nearly half of the global population; however, insect infestation could severely affect the production of this staple food. To improve rice insect resistance and reduce the levels of Bt toxin released into the environment, the Cry1Ab gene was conjugated to the rice rbcS promoter to express Bt toxin in specific tissues of transgenic plants.
Eight marker-free, T(2) lines were separated from the T(0) cotransformants. Using RT-PCR, high levels of Cry1Ab expression were detected in the leaf but not in the seed. The Cry1Ab protein level ranged from 1.66 to 3.31 µg g(-1) in the leaves of four transgenic lines, but was barely detectable in their seeds by ELISA. Bioassays showed that the mortality rate of silkworm larvae feeding on mulberry leaves dipped in transgenic rice flour and pollen was less than that of the positive control (KMD), and that their average weight was higher than that of KMD, suggesting that the Cry1Ab protein was not expressed in the seed and pollen.
The transgene conferred a high level of resistance to insects and biosafety to the rice plants, which could be directly used in rice breeding.
水稻是全球近一半人口的主要粮食资源；然而，虫害会严重影响这种主食的产量。为了提高水稻的抗虫性并减少释放到环境中的 Bt 毒素水平，Cry1Ab 基因被连接到水稻 rbcS 启动子上，以使 Bt 毒素在转基因植物的特定组织中表达。
从 T(0)共转化体中分离出 8 个无标记的 T(2)系。通过 RT-PCR，在叶片中检测到高水平的 Cry1Ab 表达，但在种子中未检测到。四个转基因系叶片中的 Cry1Ab 蛋白水平在 1.66 至 3.31 µg g(-1)之间，但通过 ELISA 在其种子中几乎检测不到。生物测定表明，取食浸过转基水稻粉和花粉的桑叶的家蚕幼虫死亡率低于阳性对照（KMD），且其平均体重高于 KMD，表明 Cry1Ab 蛋白未在种子和花粉中表达。
该转基因赋予了水稻高水平的抗虫性和生物安全性，可直接用于水稻育种。
