A novel strategy to enhance resistance to Cucumber mosaic virus in tomato by grafting to transgenic rootstocks

Cucumber mosaic virus (CMV) can infect a wide range of host species. For the lacking of CMV resistant varieties of tomato, RNA interference (RNAi) can be used as a fast and effective method for the generation of transgenic resistant varieties. In this current study, five intron-spliced hairpin RNA (ihpRNA) plant expression vectors aimed at five genes of CMV have been constructed. Transgenic tomatoes were obtained by Agrobacterium tumefaciens-mediated transformation with expression vectors. Highly resistant generations of transgenic plants were employed as rootstocks and grafted onto non-transgenic tomatoes that resulted in the successful transfer of resistance to the scions. Using a novel method of plant cuttings for rootstock propagation, we obtained large quantities of disease-resistant material. Further, this method produces scions that can remain undetectable for transgenic resistance marker genes that may provide novel approaches to evade collective concerns about genetically-modified organism (GMO) biosafety.