Double-stranded RNA (dsRNA) plays an essential role in many biological processes and has a great potential for agronomic applications in disease and pest control. A simple and effective method to monitor dsRNA uptake by fungi is crucial for the use of dsRNA as alternative fungicide. The protocol reported in this chapter describes an efficient method to detect and localize labeled dsRNA in fungal hyphae. We use the fungal Verticillium longisporum, a fungal plant pathogen that commonly infects rapeseed and other Brassica species, to explain the procedure, though we have validated the method in a broad spectrum of fungi. Hereafter we elucidate step-by-step the production, fluorescence labeling, as well as detection of dsRNA via fluorescence microscopy in fungal mycelium.
Keywords: Environmental RNAi; Fluorescent dsRNA; Hyphae; dsRNA detection.