Resistance to a DNA and a RNA virus in transgenic plants by using a single chimeric transgene construct.

Tomato leaf curl Taiwan virus (ToLCTWV) and Tomato spotted wilt virus (TSWV) are two major tomato viruses that cause serious economic losses. In this study, a partial C2 gene from ToLCTWV and the middle half of the N gene of TSWV were fused as a chimeric transgene to develop multiple virus resistance in transgenic plants. This construct was introduced into Nicotiana benthamiana and tomato by Agrobacterium-mediated transformation. Several transgenic lines showed no symptom post agro-inoculation with ToLCTWV and displayed high resistance to TSWV. The detection of siRNAs indicated that the resistance was via RNA silencing. This study demonstrated that linkage of gene segments from two viruses with distinct genomic organization, one DNA and the other RNA, can confer multiple virus resistance in transgenic plants via gene silencing.