Foliar application of clay-delivered RNA interference for whitefly control

Area of Science:

• Agricultural Entomology
• Molecular Entomology
• Biotechnology

Background:

• Whiteflies (Bemisia tabaci) are significant global agricultural pests that feed on plant phloem.
• RNA interference (RNAi) using double-stranded RNA (dsRNA) shows promise for pest control but faces challenges with dsRNA uptake and phloem delivery in sap-sucking insects.
• Developing effective RNAi-based biopesticides requires overcoming delivery limitations for broad-spectrum pest control.

Purpose of the Study:

• To investigate the efficacy of dsRNA loaded onto layered double hydroxide (LDH) nanoparticles, termed BioClay, for controlling whitefly populations.
• To assess the impact of BioClay formulation and adjuvants on dsRNA uptake, movement within the plant, and subsequent pest control.
• To evaluate the potential of BioClay as a platform for RNAi-based pest management targeting multiple life stages of whiteflies.

Main Methods:

• Identification of single and combinational target genes in whiteflies for RNAi-based control.
• Formulation of dsRNA with layered double hydroxide (LDH) to create BioClay for foliar application.
• In planta testing of BioClay spray, with and without adjuvants, to assess whitefly disruption.
• Evaluation of dsRNA movement to vascular bundles and uptake by whiteflies.

Main Results:

• Foliar application of BioClay effectively disrupted multiple developmental stages of whiteflies in planta.
• Adjuvants significantly enhanced the uptake and movement of dsRNA from foliar application to plant vascular bundles and into whiteflies.
• BioClay delivery of dsRNA provided improved protection against immature whitefly stages compared to naked dsRNA.
• The BioClay platform demonstrated potential for complete life cycle control of whiteflies.

Conclusions:

• BioClay represents a novel and effective platform for delivering dsRNA to control agricultural pests like whiteflies.
• Enhanced uptake and phloem mobility facilitated by BioClay and adjuvants are crucial for successful RNAi-based pest control in sap-sucking insects.
• This technology holds promise for developing sustainable, broad-spectrum RNAi insecticides for complete pest life cycle management.