A first greenhouse application of bacteria-expressed and nanocarrier-delivered RNA pesticide for Myzus persicae control

There are two main limitations for sprayable RNA pesticide development: delivery efficiency and synthetic cost of double-stranded RNA (dsRNA). We previously constructed a nanocarrier-based transdermal dsRNA delivery system and a novel bacteria-based hairpin RNA (hpRNA) expression system to solve these challenges. Herein, as a subsequent exploration of RNA pesticide (sprayable ds/hpRNA for pest control), we performed a greenhouse application of bacteria-expressed and nanocarrier-delivered RNA pesticide on green peach aphid. The nanoparticle SPc could combine and deliver dsRNA across the aphid cuticle and V-type proton ATPase subunits d (ATP-d) and G (ATP-G) were selected as the potential RNA interference (RNAi) targets. Our plasmid-Escherichia coli system simultaneously expressing ATP-d and ATP-G hairpin RNAs (hpRNAs) was constructed for mass production of hpRNA. The expressed hpRNA was mixed with SPc and detergent to form RNA formulation, which showed a certain insecticidal activity through the spray application in the greenhouse. Total control efficacy of our RNA pesticide could reach 61% on 3 d and maintained at 50% until the sixth day. To our knowledge, our study is the first attempt to apply the bacteria-expressed and nanocarrier-delivered RNA pesticides for pest control in the greenhouse trial, which is beneficial for promoting the development of RNA pesticides.