Virus-induced Gene Silencing in Studying Aphid Resistance in Wheat

Virus-induced gene silencing (VIGS) technology is one of the emerging reverse genetic approaches in cereal crops. The use of VIGS in studying aphid defense gene function in wheat has not been explored. Thus, Leon van Eck of Colorado State University, and colleagues, used barley stripe mosaic virus (BSMV) to target and silence a WRKY53 transcription activator and a phenylalanine-ammonia-lyase (PAL) gene which are both suspected of stimulating aphid defense in wheat. They inoculated the resistant wheat with VIGS constructs and observed that the WRKY53 levels decreased, reaching almost the same level as that of the susceptible wheat. At the same time, the PAL expression also decreased, which may imply that both genes are in the same defense response network. Aphid infestation is higher in the silenced plants and there was an increase in the fitness of the aphids compared with those feeding on the control plants. Therefore, it is confirmed that WRKY53 an d PAL  have significant functions in garnering positive resistance against aphids.