Using RNAi Cultivate Processing Tomato Resistant To ToMV

In this research, RNAi technology was used to repress the homology target gene expression of Tomato mosaic virus by degrading mRNA of target gene aiming to resist ToMV. Agrobacterium-mediated transformation has been used to introduce the RNAi vector into processing tomatoes.The conditions for regeneration and transformation of processing tomato mediated by Agrobacterium were studied with the aim of optimizing the transformation protocol.(2)Transgenic plants were tested in order to make sure that they were resistant to ToMV.During the experimmt cotyledons were taken as explants,first We added different concentrations of Kanamycin into MS basic medium in order to test whether they were resistant to Kanamycin.We Found that the differentiation of cotyledon explants were inhibited in different degrees.And then different concentrations of kanamycin was added into induction medium. The first ten days we added 10mg/L kanamycin into induction medium,The second ten days we added 30mg/L,and from then on we added 50mg/L. We added different concentrations and types of cytokinins into bud induction medium.ZT0.5 mg/L,1.0 mg/L or 6-BA2.0 mg/1 was added into bud induction medium in order to choose the best concentration and type of cytokinins for bud induction.After infection,we studied inflution of temperature on bud induction.explants were placed in 23～24℃and 26～28℃temperature, other things were equal.PCR amplication showed that fragments of ToMV was integrated into genome of transgenic tomato plants. The result showed transgenic tomato plants are resistant to ToMV when infected with ToMVThrough the experimmt we got such result:(1) After 4d pre-culture,3d co-culture, and 12weeks of selective culture with 10～30～50 mg/L kanamycin, in the first ten days concentrations of kanamycin in bud induction medium were 10mg/L, in the second ten days concentrations of kanamycin in bud induction medium were 30mg/L, and from then on concentrations of kanamycin were 50mg/L. 0.5mg/LZT, 0.1mg/LIAA was added into bud induction medium, explants were placed under 23～24℃condition,the best transformation efficiencies could be obtained.(2) Transgenic plants are resistant to ToMV.Different fragments of ToMV were selected to contruct RNAi vector.The result showed fragments of ToMV has influences on resistance to ToMVThrough the experiment we found that the best transformation efficiencies could be obtained by improving conditions.Genetic engineering technology open up new ways to plant antiviral breeding. It is possible to cultivate processing tomato resistant to ToMV using RNAi.