Induction of Resistance to Grapevine fanleaf Virus (GFLV) by RNA Silencing Method

Plant viruses have been the limiting factor in agriculture. To date, 63 viral agents infecting grapes have been identified around the world. One of the most destructive of these agents is GFLV. To control these pathogens, traditional methods, such as crop rotation, early detection and elimination of infected plants, eradication of the infection source plants, cross protection, genetically modified plants for resistance and chemical control of vectors, have been used. The most efficient method to control viruses is the use of resistant plant varieties and the RNA Silencing-based resistance is the best way to establish the resistance to viruses in plants. In this study, the possibility of induction of resistance to GFLV using a partial GFLV RdRP gene sequence was evaluated. For this purpose, a hairpin construct containing intron and a partial RdRP gene sequence was developed. Agrobacterium tumefaciens was used for N. benthamiana transformation. 40 lines of transgenic N. benthamiana plants were created and confirmed by PCR reactions. The transgenic plants were mechanically inoculated with GFLV in order to evaluate their resistance to GFLV. The results of ELISA testing and plant symptoms showed that 27.5% of transgenic plants were resistant to GFLV and 40% of them showed the symptom and infection with delay. In this research, in addition to produce transgenic N. benthamiana plants resistant to GFLV, the results showed that the used hairpin construct is efficient to establish resistance to this virus and it could apply to produce resistance in grape and other host plants.