Wheat DFR gene editing for fusarium head blight and crown rot resistance

Overview

Fusarium head blight (FHB) and Fusarium crown rot (FCR) are devastating wheat diseases that cause significant yield losses and mycotoxin contamination worldwide. This research builds on compelling evidence from barley showing that kernel flavonoid content and composition confer resistance to these pathogens. By targeting the dihydroflavonol reductase (DFR) gene, a key enzyme in the flavonoid biosynthetic pathway, this approach aims to develop wheat genotypes with durable, broad-spectrum resistance to Fusarium infections.

The solution addresses a critical need in wheat breeding for sustainable disease management strategies that reduce reliance on fungicides while protecting grain quality and food safety.

Technical specifications

• Gene target: Dihydroflavonol reductase (DFR) genes located on the long arms of wheat chromosomes 3A, 3B, and 3D
• Approach 1: TILLING-based mutagenesis to identify wheat lines with premature stop codons in DFR gene copies in both pasta and common wheat
• Approach 2: CRISPR-based genome editing of wheat DFR genes in a moderately FHB-resistant background
• Delivery method: Carbon dot-based delivery system for genome editing reagents, optimized in the investigator's laboratory
• Resistance mechanism: Accumulation of dihydroquercetin in seeds, which suppresses mycelial growth and macrospore formation, preventing fungal penetration of the seed coat
• Validation methods: HPLC analysis for flavonoid content profiling and pathogen challenge assays for FHB and FCR resistance
• Genetic strategy: Stacking single amber mutations via genetic crossing to produce double and triple mutants for enhanced resistance

Technology readiness level

This research is currently at TRL 3-4 (proof-of-concept and validation in laboratory conditions). The wheat DFR genes have been cloned and assigned to specific chromosomal locations. TILLING mutants with premature stop codons have been identified in both pasta and common wheat genotypes. Current work focuses on stacking single mutations to create double and triple mutants through genetic crossing, with ongoing validation of resistance phenotypes. Future validation includes CRISPR-based genome editing and comprehensive testing for flavonoid content and pathogen resistance. The approach is ready for collaborative partnerships to advance toward field trials and commercial wheat variety development.