The tomato yellow leaf curl virus satellite DNA was used as vector which containing the Su gene, and transformed the plasmid into Agrobacterium by freeze thawing method. Agrobacterium infected plants via root absorption, and virus-induced gene silencing system was optimized, twexplore the influence to virus-induced gene silencing efficiency. The results showed infected 22-25 days tomato seedling via OD600 1.5 Agrobacterium-mediated root-absorption which containing plasmid pBinPLUS-2mβ-Su and pBinPLUS-1.7A, ...