Methyl benzoate-based compounds for rice planthopper control and plant defense induction

Overview

Rice planthoppers are among the most destructive pests affecting rice production globally, causing significant yield losses and requiring heavy insecticide use. This research proposes a dual-pronged, biology-based pest management approach built on methyl benzoate-related compounds (MBCs), which are natural volatile chemicals released by rice seedlings when attacked by planthoppers or Lepidoptera larvae.

The solution targets two complementary mechanisms: direct application of MBC-based chemicals that repel planthoppers and attract their natural enemies such as the egg-parasitic wasp Anagrus nilaparvatae, and plant defense inducers (PDIs) that stimulate rice plants to produce their own protective MBCs. Together, these approaches offer a more sustainable alternative to conventional insecticides while supporting integrated pest management.

Technical specifications

Core discovery:

• A key gene controlling MBC biosynthesis in rice has been identified through genetic and genomic analysis
• Genome-edited rice mutants lacking this gene fail to produce MBCs under attack, suffer greater planthopper damage, and attract fewer parasitic wasps

MBC-based chemical formulation:

• Methyl benzoate, methyl salicylate, and methyl o-methoxybenzoate identified as primary active MBCs
• Each compound demonstrated repellent effects on planthopper feeding and oviposition
• Methyl benzoate and methyl salicylate showed strong attraction activity for the egg-parasitic wasp

Plant defense inducer (PDI) screening:

• High-throughput screening using a Promoter:GUS reporter rice line linked to the MBC synthase gene
• Screening of the Otava natural-like chemical library and AI-identified plant defense hormone analogs (in collaboration with Atomwise)
• Hormone signaling pathways confirmed as regulators of MBC synthase expression

Technology readiness level

The technology is currently at an early-to-mid stage of development. Laboratory validation has confirmed the biological role of MBCs in repelling planthoppers and recruiting their natural enemies. Future work will focus on optimizing MBC concentrations and combinations through controlled bioassays with planthoppers and parasitic wasps, followed by field validation. Parallel efforts will screen chemical libraries to identify effective PDIs that activate MBC production in rice plants. The approach is positioned for translational development toward practical field deployment in rice pest management programs.