Fungi are the most economically devastating class of plant pathogens and affect a wide range of crops critical to global food security

The Department of Agriculture National Institute of Food and Agriculture awarded $299,544 to the Connecticut Agricultural Experimental Station on February 1, 2026, under the Agriculture and Food Research Initiative (AFRI) program to investigate RNA interference (RNAi) as a fungal disease control mechanism in soybeans.

The research addresses knowledge gaps in the intraspecies susceptibility of Sclerotinia sclerotiorum to RNAi and the durability of this technology across multiple pathogen generations. The project will use a large, genetically and geographically diverse collection of fungal isolates to challenge transgenic soybeans engineered with host-induced gene silencing (HIGS) targeting critical virulence genes. The work will evaluate both the prevalence and mechanistic basis of RNAi insensitivity within the isolate collection, then sequentially infect resistant HIGS lines to select for isolates capable of breaking RNAi-mediated resistance, generating data on the resilience and molecular weak points of the technology. The project will also validate the use of tRNA-like motifs to increase double-stranded RNA systemic activity and enable fungal disease control without regulatory burdens associated with traditional genetically modified organisms. The research will guide future integration of RNAi into integrated pest management practices and support development of highly systemic dsRNA technology for environmentally sustainable fungal disease control.

Work is performed in New Haven, Connecticut, with a period of performance from February 1, 2026, through January 31, 2028.

RNA interference (rnai) has emerged as a promising technology to combat fungal diseases, but substantial knowledge gaps in application limit its usage. This project will address critical questions surrounding the intraspecies susceptibility of s. Sclerotiorum to rnai and the durability of this technology across multiple pathogen generations. To achieve this, we will use a large collection of isolates with robust genetic, geographic and host range diversity. This collection will be used to challenge transgenic soybeans targeting critical virulence genes through host induced gene silencing (higs) and both the ubiquity and mechanistic basis of rnai insensitivity in the collection will be evaluated. Simultaneously, multiple isolates will be used to sequentially infect resistant higs lines and select for isolates capable of breaking rnai-mediated resistance, thus generating critical data on the resilience and molecular weak points of this technology. Finally, to investigate novel uses of rnai, we will validate the usage of trna-like motifs as a possible approach to increase dsrna systemic activity and control fungal diseases without the regulatory burden of traditional gmos. In the future this work will guide the integration of rnai into current IPM practices and lead to the development of highly systemic dsrna technology to facilitate environmentally sustainable control of fungal diseases.