Common bean (Phaseolus vulgaris) is the world most important food legume for direct human consumption in developing countries. There are several destructive virus diseases causing significant yield reduction belonging primarily to the familes Potyviridae and Bromoviridae. These viruses are transmitted by aphids and also through seeds and are distributed worldwide. An effective method for obtaining resistant stock would be to produce transgenic plants expressing virus-derived dsRNA. The aim of this study is produce transgenic common bean that is simultaneously resistant to bean common mosaic virus, bean common mosaic necrosis virus, and cucumber mosaic virus using RNAi technology. Several sense, antisense and hairpin constructs were prepared containing gene fragments of BCMV CP, BCMNV HC-pro, CMV 2b, and another construct that contains the same fragments of all three genes. The constructs efficiency was checked in Nicotiana benthamiana, and N. tabacum transiently. After two weeks, phenotypic and serologic analysis showed significant resistance in transgenic plants prepared using this construct than plants transformed with an empty vector. We noted similar levels of virus resistance among plants containing siRNAs targeting a single virus than the serrate construct targeting three viruses. The results showed 2 weeks after inoculation plants without constructs shows symptoms including growth reduction and malformation but plants were inoculated with constructs were shows symptoms until five weeks. These outcomes provide the basis for an expanding bean transformation program.
