High throughput screening platform for insecticidal plant formulations using axenic whitefly colonies

Overview

This solution offers a high throughput, compact screening methodology for evaluating insecticidal formulations derived from plant-expressed genes. By combining transient gene expression in Nicotiana benthamiana with axenic (germ-free) whitefly colonies and synthetic membrane feeding systems, the platform enables rapid, quantitative assessment of insecticidal activity against phloem-feeding insects. The approach replaces labor-intensive whole-plant bioassays with a streamlined, laboratory-scale workflow that reduces space requirements and improves reproducibility. It is designed to accommodate a range of insecticidal modalities, including protein toxins, RNAi, and amiRNA constructs.

Technical specifications

Key features:

• In vitro membrane feeding system using asymmetric membranes fabricated into GA7 tissue culture vessels for aseptic delivery of test compounds
• Transient expression of insecticidal genes in N. benthamiana (acyl sugar knockout) for rapid production of candidate biomolecules
• Small-scale axenic whitefly colonies enabling quantitative inoculation and population health modeling
• Phloem-specific and apoplastic expression options demonstrated via mCherry tomato visualization and confocal microscopy confirmation of uptake
• Support for multiple insecticidal formats including plant codon-optimized protein toxins, RNAi, and amiRNA feeding
• Texas red synthetic phloem validated as a tracking tool for confirming ingestion through membrane feeding

How it works:

Candidate insecticidal genes are transiently expressed in N. benthamiana. Protein extracts or filter-sterilized viral infective clones are delivered to axenic whitefly colonies through sterile membranes. Whitefly proliferation is measured to a standardized endpoint, enabling dose-response comparisons and quantitative ranking of insecticidal formulations.

Technology readiness level

The platform is currently at a proof-of-principle stage. Key components have been individually validated, including establishment of axenic whitefly colonies, membrane feeding with synthetic phloem, and visualization of gene product uptake. A dozen insecticidal protein candidates are already available for testing. Future validation will focus on standardized dose-response feeding assays and quantitative comparison protocols. The team is open to collaborative input on insecticidal formulation specifics to broaden the screening dimensions of the technology.