Screening and production of dsRNA molecules for protecting Cucumis sativus against Cucumber mosaic virus through foliar application

Cucumber mosaic virus (CMV), which is one of the most prevalent plant viruses, harms many crops around the word. Although CMV causes severe economic losses to agriculture, successful prevention and treatment strategies are lacking. RNA interference (RNAi) is a promising strategy for the control of CMV because of its impressive specificity and sustainability. Here, a bacterial expression approach was conducted to produce hairpin RNA, and the best expression conditions to produce a high yield of dsRNA were explored. The highest expression of dsRNA in Escherichia coli HT115 was achieved at 37 °C using 2 mM IPTG and 17 h post-induction. For resistance analysis, six dsRNA molecules were constructed for CMV 1a, 2a, 3a and coat protein (CP). In cucumber ( Cucumis sativus ), foliar application of dsRNA preparations derived from CMV-1a and CMV-2a proteins conferred efficient protection against CMV. Our findings confirm that the exogenous application of dsRNA with a bacterial prokaryotic expression system could be a powerful biotechnological tool to protect plants against virus infections.