Methionine-Based Sulfonium Lipid Mediates dsRNA for Gene Silencing in Pests

Effective gene carriers will promote the application of RNA interference (RNAi) technology in future pesticide development. This paper reports a group of novel methionine-based sulfonium lipid compounds (MSLs) and screens their gene delivery abilities in vitro and in vivo. Experiments showed that most MSLs could encapsulate nucleic acids into nanoparticles at an S/P ratio of 4:1, with nanoparticle sizes ranging from 124 to 216 nm and zeta potentials ranging from +27 to 40 mV, and could effectively protect nucleic acids from enzymatic degradation. MSLs successfully mediated the cellular uptake and transfection of nucleic acids in Kc cells and insects. Using dsRNA of CHT10 as the RNAi target, four MSLs were proven to mediate dsRNA interference in Drosophila melanogaster and Ostrinia furnacalis and achieved significant growth inhibition during larval development, eventually leading to pest death. The study demonstrates that MSLs are useful nanocarriers for the development of dsRNA pesticides.