In vitro RNA-mediated gene silencing of Fusarium oxysporum f.sp. cubense from Ecuador and assessment of RNAi molecule stability in banana plants

Abstract

Objective Fusarium wilt poses a significant threat to banana production, caused by diverse clonal Fusarium lineages. Given the lack of curative measures, developing effective treatments is crucial. RNA interference (RNAi) technology, utilizing double-stranded RNA (dsRNA) molecules, offers a promising solution. In this study, RNAi was evaluated by silencing the activity of the Beta-tubulin (Focβ-tub), C5 Sterol desaturase (FocERG3) and Chitin synthase 1 (FocChs1) genes in a pathogenic Fusarium strain. Furthermore, we study the potential of dsRNA translocation in 3 months old banana plants at early hours of been spray under greenhouse conditions. Results In vitro results demonstrated that dsRNA-FocChs1 was more effective in inhibiting spores, with an average IC₅₀ of 156.84 mg/L, compared to dsRNA-Focβ-tub (IC₅₀: 532.7 mg/L), dsRNA-FocERG3 (IC₅₀: 635.59 mg/L), and a positive control (IC₅₀: 243.91 mg/L). A greenhouse test was conducted to evaluate the translocation of dsRNA in banana plants. The results demonstrated that the dsRNA remained on the applied leaf without degradation up to 48 hours post-application (hpa). However, no translocation to other plant tissues was detected until the last time point. Further time points should be evaluated to ascertain the dsRNA translocation to other banana plant tissue.