Key facts
- Researchers identified microbial compounds with potential as future fungicide leads.
- The study focused on suppressing Zymoseptoria tritici, a major wheat pathogen.
- A pipeline combining bioassay, genome mining, and chemistry was used.
- 52 out of 534 environmental Pseudomonas isolates showed suppression of Z. tritici.
- The study identified the known antifungal compound 2,4-diacetylphloroglucinol (2,4-DAPG).
- Some isolates may produce previously unknown antifungal molecules.
Researchers at Rothamsted Research have identified potential new fungicide leads by screening environmental bacteria. The study focused on Zymoseptoria tritici, a significant pathogen affecting wheat crops, which has developed resistance to existing fungicides, making new control methods urgent. The research team utilized a high-throughput 'in vitro' bioassay to screen 534 environmental Pseudomonas isolates, identifying 52 that could suppress a standard Z. tritici strain. These promising isolates were further tested against a panel of 12 genetically diverse Z. tritici strains collected across Europe, revealing variations in inhibition strength. The analysis pointed to bacterial genes involved in producing antifungal molecules, including the known compound 2,4-diacetylphloroglucinol (2,4-DAPG). A proof-of-concept experiment showed that disrupting a key gene for 2,4-DAPG production led to a loss of both the compound and the bacteria's ability to inhibit Z. tritici. Crucially, the study also identified antagonistic isolates whose activity could not be explained by known gene clusters, suggesting the potential production of novel antifungal molecules. This pipeline offers a practical method for discovering future fungicide leads from bacteria, allowing for earlier testing against diverse pathogen populations.