Chitosan-encapsulated sirna biopesticide for citrus psyllid control

Overview

This research proposes a chitosan nanoparticle-based platform for delivering small interfering RNA (siRNA) to the Asian citrus psyllid (Diaphorina citri), a key insect vector responsible for spreading Huanglongbing (HLB), one of the most destructive diseases affecting citrus crops worldwide. By nanoencapsulating gene-silencing siRNAs within chitosan particles, the technology aims to enable oral delivery through feeding, triggering targeted gene silencing and psyllid mortality. This approach represents a promising biocontrol alternative that could reduce reliance on broad-spectrum chemical pesticides and help protect citrus production.

Technical specifications

• Target organism: Diaphorina citri (Asian citrus psyllid), vector of HLB
• Active mechanism: RNA interference (RNAi) via siRNA-mediated gene silencing
• Delivery vehicle: Chitosan nanoparticles assembled using the ionic gelation method
• Target genes: SOD, AWD, WTN, and Rac1, all associated with psyllid development
• Prior validation: Direct soaking application of unencapsulated siRNA cocktails achieved 10-40% mortality in psyllids and confirmed gene silencing via RT-qPCR
• Proposed delivery method: siRNA-loaded chitosan nanoparticles applied to leaf surfaces, allowing psyllids to ingest the particles during feeding
• Evaluation approach: Mortality monitoring combined with RT-qPCR analysis using the comparative Ct method to quantify mRNA fold reduction
• Specificity testing: Planned assessment to confirm the biopesticide does not adversely affect non-target species

Technology readiness level

The technology is currently at an early-to-mid stage of development. Laboratory proof-of-concept has been established, demonstrating that siRNA cocktails applied through soaking can silence target genes and induce mortality in D. citri. The next phase of validation focuses on confirming whether chitosan nanoencapsulation enables effective siRNA delivery through feeding, including nanoparticle characterization (particle formation and size), feeding-based mortality assays, and gene expression analysis. Additional specificity testing against unintended species is planned to support potential field application. The technology requires further optimization and field validation before commercial deployment.