MYCOLab Ai Logo - gold and army green

Control effects and mechanisms of metabolites from Streptomyces ahygroscopicus var. gongzhulingensis strain 769 on sclerotinia rot in sunflowers

Summary

Scientists discovered that a beneficial soil bacterium called Streptomyces can effectively control sunflower rot disease caused by a harmful fungus. When applied to soil or roots, this bacterium reduced disease severity by over 50% and improved plant root health and seed quality. The treatment works by both directly killing the pathogenic fungus and strengthening the plant’s natural defense systems.

Background

Sunflower sclerotinia rot caused by Sclerotinia sclerotiorum is a significant threat to global agriculture. Chemical control has led to pesticide resistance and environmental pollution. Streptomyces species are known for producing bioactive secondary metabolites with antifungal properties.

Objective

To investigate the control efficacy of S. ahygroscopicus var. gongzhulingensis strain 769 (S769) metabolites against sunflower sclerotinia rot and elucidate the underlying mechanisms through in vitro, pot, and field trials.

Results

S769 exhibited 65.79% mycelial growth inhibition in vitro and significantly reduced disease severity in field trials (7.36% and 5.92% vs. 14.69% control). Treatment increased root fresh weight by 15.85% and reduced shriveled seeds by 34.26%. Transcriptomics revealed 6,622 upregulated genes including MAPK signaling and phenylpropanoid biosynthesis pathways.

Conclusion

S769 demonstrates dual action through direct antifungal effects and host defense activation. The enrichment of beneficial rhizobacteria without altering microbial diversity highlights its potential as a sustainable biological control agent for sclerotinia rot management in sunflowers.
  • Published in:Frontiers in Plant Science,
  • Study Type:Field Trial and Mechanistic Study,
  • Source: 10.3389/fpls.2025.1649819
Scroll to Top