Reduction of Phakopsora pachyrhizi infection on soybean through host‐ and spray‐induced gene silencing

摘要

Asian soybean rust (ASR), caused by the obligate fungal pathogen , often leads to significant yield losses and can only be managed through fungicide applications currently. In the present study, eight urediniospore germination or appressorium formation induced genes were investigated for their feasibility to suppress ASR through a bean pod mottle virus (BPMV)‐based host‐induced gene silencing (HIGS) strategy. Soybean plants expressing three of these modified BPMV vectors suppressed the expression of their corresponding target gene by 45%–80%, fungal biomass accumulation by 58%–80%, and significantly reduced ASR symptom development in soybean leaves after the plants were inoculated with , demonstrating that HIGS can be used to manage ASR. In addition, when the in vitro synthesized double‐stranded RNAs (dsRNAs) for three of the genes encoding an acetyl‐CoA acyltransferase, a 40S ribosomal protein S16, and glycine cleavage system H protein were sprayed directly onto detached soybean leaves prior to inoculation, they also resulted in an average of over 73% reduction of pustule numbers and 75% reduction in biomass accumulation on the detached leaves compared to the controls. To the best of our knowledge, this is the first report of suppressing infection in soybean through both HIGS and spray‐induced gene silencing. It was demonstrated that either HIGS constructs targeting genes or direct dsRNA spray application could be an effective strategy for reducing ASR development on soybean.