Crops constantly experience various biotic stresses during their life cycle, and Fusarium spp. remain one of the most serious groups of pathogens affecting plants. The ability to manipulate the expression of certain microorganism genes via RNAi creates the opportunity for new-generation dsRNA-based preparations to control a large number of diseases. In this study, we applied virus-induced gene silencing (VIGS), and spray-induced gene silencing (SIGS) to silence the trichothecene-producing gene TRI5 in F. culmorum as a means to reduce its aggressiveness on spring wheat. Treatment of the fungus with dsTRI5RNA in vitro reduced deoxynivalenol (DON) and 3-acetyldeoxynivalenol (3-A-DON) accumulations by 53–85% and 61–87%, respectively, and reduced TRI5 expression by 84–97%. VIGS decreased the proportion of infected wheat spikelets by 73%, but upregulation was observed for TRI5. SIGS on wheat leaves and ears using certain dsTRI5RNA amounts negatively impacted F. culmorum growth. However, when performing in vivo analyses of TRI5 mRNA levels, the upregulation of the gene was determined in the variants where fungal colonization was restricted, suggesting a compensatory reaction of the pathogen to RNAi.

Double-stranded small RNAs (dsRNA) perform various regulatory functions via RNA-interference. Additionally, they can be transported between various plant species and their pathogens and pests via extracellular vesicles, protecting RNA from nucleases. Plants secrete short dsRNA molecules to defend themselves against pathogens. The latter also use small RNAs when infecting crops. Some dsRNAs of pathogens are known as ribonucleic effectors. Host-induced gene silencing (HIGS) was shown to be effective when breeding resistant varieties and analyzing plant-pathogen interactions. However, complexity of transgenesis and society fear of genetically modified products make HIGS application difficult. The appearance of a new strategy based on plant spraying with dsRNA gave a new perspective of plant protection. Currently such a strategy requires accurate studying as well as the development of efficient systems stably producing high-quality dsRNA.