Potato Anti-virus And Potato Starch Improved By RNA Interference

Potato is the third-largest food crop after rice and wheat. It is cultivated widely in different areas of this world, not only as food and vegetables, but also as an important industrial raw material. Potato viruses have caused great damage each year, including reducing potato yield and decreasing potato quality. Potato virus X(PVX), Potato virus Y(PVY) and Potato leaf roll virus(PLRV) is the most serious pathogens among all of the potato viruses. In order to reduce the damage caused by the potato viruses, breeding of antiviral potato is an economic and effective way using RNAi technology. In this study I have constructed silencing vectors carrying sequences from single or multiple viruses. These sequences are part of genes encoding the coat protein of PVX, PVY and PLRV. These constrcts were introduced into an elite potato cultivar by Agrobacterium tumefactions-mediated transformation. Transgenic plants potentially resistant to single and multiple potato viruses were obtained and will be confirmed by DSA-ELISA.Potato amylopectin that has unique structure and physicochemical properties is an important industrial raw material which are widely used in the field of food adhesives, feed, casting, fuel and so on. Potato starches are a mixture of amylopectin and amylose in nature. Separation of amylose and Amylopectin consumes a lot of energy and water. Therefore breeding of high amylopectin potato is of great significance. The potato viral disease is serious problem in potato production. In order to breed potato which is resistant to major potato viruses and contain amylose-free starch, I have also constructed silencing vectors carrying chimeric sequences derived from the coat protein genes of PVX, PVY, PLRV and granule-bound starch synthase gene (GBSS). I have examined the expression level of GBSS in leaves of a few transgenic plants and showed the GBSS is significantly reduced, suggesting that the dsRNA targeting GBSS is sufficient to silence the GBSS at lest in leaves. Further evaluation of resistance to viruses and contents of amylose will be done when the transgenic plants are at suitable stages.