A novel carbon quantum dot-based system delivering double-stranded RNA targeting susceptibility genes in tomato could control gray mold (Botrytis cinerea)

Gray mold is a fungal disease that affects many crops, including tomatoes, and causes massive economic losses worldwide. A novel control system is urgently needed because of the fungus’s high genetic variability and resistance to multiple fungicides. Spray-induced gene silencing is an effective way to control plant pests by triggering RNA interference (RNAi) and blocking key genes in them. However, directly silencing susceptibility genes in plants to control disease remains to be studied. This approach could be a more efficient way to induce RNAi than targeting the pest’s genes. Here, three disease susceptibility genes of tomato were efficiently targeted by RNA based nano fungicides coupled with double-stranded RNA-carbon quantum dots (dsRNA-CDs). The novel RNA based nano fungicides offered an excellent effect on dsRNA preservation and cellular delivery, also facilitated the production of jasmonic acid in plants, which enabled these fungicides with good inhibitory effects on gray mold, indicating that they could be a promising way to control this notorious disease. Moreover, the fungicides specifically silenced the target genes and had no side effects on plants. Therefore, the novel RNA based nano fungicides could be efficient tools to control gray mold in tomatoes, and the plant susceptibility gene-based system is a potential way to control various plant diseases.