Targeting gut surface proteins in Diaphorina citri by RNA interference reduces uptake of Candidatus Liberibacter...

The Asian citrus psyllid, Diaphorina citri, vectors Candidatus Liberibacter asiaticus (CLas) that causes citrus greening disease, which has devastated global citrus production. Current management primarily relies on the application of synthetic chemical insecticides, resulting in the evolution of resistance among D. citri populations. CLas is ingested by D. citri while feeding on infected plants and subsequently interacts with the gut epithelial surface to establish infection. To determine the functional significance of abundant gut surface proteins in D. citri during CLas uptake, we used RNA interference (RNAi) to silence nine key gut surface protein genes.

Following membrane feeding on double-stranded RNAs (dsRNAs), transcript levels were reduced by 20-51% in adults and 28-50% in nymphs at 72 h, with higher knockdown efficiencies of 41-63% in adults and 30-81% in nymphs by 120 h. Some dsRNA treatments increased D. citri mortality by approximately 20% over the control treatment, and two treatments reduced honeydew production indicative of reduced feeding consistent with disrupted gut function. Silencing of several individual proteins, including alkaline phosphatase, cadherin, cluster of calcium-transporting ATPase, croquemort and monocarboxylate transporter, reduced CLas uptake in nymphs and/or adults.

Silencing of abundant gut surface proteins in D. citri limited CLas uptake, establishing a functional basis for RNAi-mediated suppression of pathogen uptake. While additional studies are needed to determine specific molecular interactions, these results identify gut surface proteins as promising targets for RNAi-based interventions to reduce CLas uptake by psyllids. © 2026 Society of Chemical Industry.