Using RNAi Technology To Cultivate New Rice Varieties Against Rice Black-streaked Dwarf Virus Disease

Rice black-streaked dwarf disease, caused by rice black-streaked dwarf virus (RBSDV), is a disastrous disease and spreads wildly in our country. The plants infected by RBSDV show obvious dwarf, abnormal heading, stagnant growth and development. RBSDV has10double-stranded RNA, S1-S10. Laodelphax striatellus, the main transmitting vector of RBSDV, can spread RBSDV permently through all the life. Therefore, to control this disease, we should not only control the virus itself, blocking the virus transmitting vector is also necessary. In this study, we constructed RNAi vectors of RBSDV S3and S8and Laodelphax striatellus’s genes related to reproductive development. Then, the RNAi vectors were transformed into RBSDV susceptible rice variety Wulingjing through agrobacterium transformation system. The main results of this study are as follows:1. Constructed RBSDV S3(inner capsid protein, the virus structural protein) RNAi vector pANDA-S3i. Then, transformed the vector into Wulingjing, and got31transgenic plants, of which there are11positive transgenic plants. The positive S3RNAi plants show resistance to RBSDV compared with the donor Wulingjing.2. The RBSDV S8(structure protein, transcription factors) RNAi vector pANDA-S8i was also constructed and transformed into Wulingjing. At last, we got42transgenic plants, of which there are9positive transgenic plants. However, the positive S8RNAi plants didn’t show obvious resistance against RBSDV compared with the donor Wulingjing.3. We also constructed RNAi vectors of Laodelphax striatellus genes related reproductive development, which are Ecdysone Receptor genes{Ecrl and Ecr2), Tubulin (C1tub1, C2tub1, C2tub2and C3tub1), Trehalase genes (Solu2and Memb2), insect intestinal mucin protein (Putal and Puta2) and Juvenile Hormone Binding protein (Juvef).4. We constructed effectively system of Laodelphax striatellus spreading RBSDV indoors.