RNAi-mediated reduction of gut surface protein expression in Diaphorina citri reduces acquisition of Candidatus liberibacter asiaticus

The Asian citrus psyllid, Diaphorina citri, transmits Candidatus Liberibacter asiaticus (CLas), the causative agent of citrus greening disease. Current management strategies primarily rely on synthetic chemical insecticides, leading to the evolution of resistance in D. citri populations. CLas is acquired by D. citri through feeding on infected plants and interacts with the surface of the D. citri gut to infect gut epithelial cells. To investigate the role of abundant gut surface proteins in CLas acquisition, we employed RNA interference (RNAi) to silence selected gut-expressed genes in D. citri via double-stranded RNA (dsRNA). Insects were fed dsRNA or control treatments via membrane feeding assays. Membrane feeding of dsRNAs resulted in reduced transcript levels in both nymphs and adults, with maximum knockdown observed at 72 h or 120 h post-treatment, depending on the target gene. Knockdown of specific targets significantly reduced CLas acquisition in both nymphs and adults. Some dsRNA treatments inducing D. citri nymph and/or adult mortality also decreased honeydew production, consistent with antifeedant effects. Although reduced feeding prevents identification of specific CLas entry receptors, the data implies these surface proteins in both vector competence and survival. RNAi-based targeting of gut surface proteins provides a potential strategy for disrupting CLas transmission and developing novel disease management tools.