利用RNAi技术防治稻纵卷叶螟的研究

Rice (Oryza sativa) is one of the most important food crops, and the rice leaf folder (RLF), Cnaphalocrocis medinalis, is a serious rice pest in Asia. This project will focus on Agrobacterium-mediated transformation of the target sequences of trehalase (CmTre) and chitin synthase (CmCHS) genes from RLF chitin synthesis pathway into Fuhui 838 rice, the hybridization analysis and insect-resistant identification of the transgenic rice, and screening homozygous transgenic lines with excellent insect resistance. Research objectives are: establishing a technology platform that is used to control rice pests by transgenic RNA interference (RNAi) technique; and breeding transgenic lines with high insect resistance and excellent yield traits. Research contents include: constructing RNAi expression vestors; Agrobacterium-mediated transformation of rice and identification; expression analyses of the RNAi vectors in transgenic rice; indoor and field insect-resistant identification and yield investigation of the transgenic lines; and detection of RNAi efficacy in RLF. The scientific issue to be resolved is: transgenic rice engineered to express dsRNAs of RLF CmTre and CmCHS can resist insect pests, thereby reducing in RLF feeding damage. This is a new strategy for the control of rice pests. The previous preliminary research can pave the way for this project that is a new exploration of biological control of rice pests. This project would be helpful to effective control of rice pests, assurance of high-yield and top-quality rice, and protection of the ecological environment.

水稻是主要粮食作物之一，稻纵卷叶螟是一种主要的水稻害虫。本项目以农杆菌介导将稻纵卷叶螟几丁质合成通路上的海藻糖酶基因(CmTre)和几丁质合成酶基因(CmCHS)的靶点序列转入辐恢838水稻，经杂交分析和抗虫性鉴定，筛选出抗虫性优良的纯合转基因株系。主要研究目标是：建立转基因水稻RNAi防治害虫的技术平台；培育出高抗虫性及产量性状优良的转基因水稻株系。主要研究内容及拟解决的科学问题：构建RNAi植物表达载体；农杆菌介导转化水稻及鉴定；转基因植株中干扰载体的表达分析；转基因植株室内和田间抗虫性鉴定及产量性状考察；稻纵卷叶螟RNAi效应检测。实现用转基因RNAi技术防治稻纵卷叶螟，这是防治水稻害虫的新策略。 本项目有扎实预研基础，是对水稻害虫生物防治的新探索，对于有效控制水稻害虫、保障水稻高产优质、保护生态环境具有重要意义。

水稻是主要粮食作物之一，稻纵卷叶螟是水稻主要害虫之一。本项目利用RNA干扰（RNAi）技术，将稻纵卷叶螟几丁质合成通路上的海藻糖酶基因CmTre（包括CmTre1和CmTre2）和几丁质合成酶基因CmCHS（包括CmCHSA和CmCHSB）的双链RNA（dsRNA）导入水稻植株，稻纵卷叶螟取食水稻时摄入靶基因dsRNA，在体内产生siRNA引起RNA干扰效应，沉默CmTre和CmCHS基因，几丁质不能正常合成，从而引起该害虫发育障碍或死亡，实现防治害虫的目的。CmTre1水稻株系抗虫效率为70%，田间平均每株卷叶率为1.43%，平均每株白叶率为0.99%。CmTre2水稻株系抗虫效率为66.67%，田间平均卷叶率为13.4%，平均白叶率为12.47%。CmTre水稻株系抗虫效率为76.64%，田间平均卷叶率为12.61%，平均白叶率为11.84%。CmCHSA水稻株系抗虫效率为56%，田间平均卷叶率为13.96%，平均白叶率为8.45%。CmCHSB水稻株系抗虫效率为61%，田间平均卷叶率为10.25%，平均白叶率为7.54%。CmCHS水稻株系抗虫效率为77.94%，田间平均卷叶率为9.78%，平均白叶率为7.67%。CmTre-CmCHS水稻株系抗虫效率为78.34%，田间平均卷叶率为8.24%，平均白叶率为6.32%。上述水稻株系的抗虫效率、卷叶率和白叶率与对照相比均具有显著差异。本项目是对水稻害虫绿色防控的新探索，用RNAi技术防治水稻害虫，具有环境友好、绿色安全等优点，对于保障稻米优质安全、保护生态环境具有重要意义。