Plant Coumarins Modulate Natural Product Biosynthesis in a Streptomyces Root Endophyte

Area of Science:

• Microbiology
• Plant Science
• Natural Product Chemistry

Background:

• The plant microbiome is crucial for plant health, with Streptomyces species producing beneficial natural products.
• Coumarins, plant metabolites, influence root microbiomes, but their effect on microbial biosynthesis is unclear.

Purpose of the Study:

• To investigate how coumarins scopoletin and scopolin affect the specialized metabolism of the Arabidopsis root endophyte Streptomyces sp. ATMOS53.
• To understand the impact of coumarins on microbial natural product biosynthesis and antimicrobial activity.

Main Methods:

• Multiomics analyses (genomics, transcriptomics, metabolomics) were employed.
• Streptomyces sp. ATMOS53 was treated with scopoletin and scopolin.
• Antimicrobial activity assays were performed against Bacillus and Paenibacillus species.

Main Results:

• Coumarins activated pyrrolizidine alkaloid (bohemamines) biosynthesis.
• Anthracycline biosynthesis was altered, with reduced late-stage products and accumulation of early shunt metabolites.
• This resulted in decreased antimicrobial activity of Streptomyces sp. ATMOS53.
• Coumarin-mediated repression of anthracycline production was conserved in Streptomyces peucetius and Streptomyces galilaeus.

Conclusions:

• Coumarins act as significant modulators of Streptomyces specialized metabolism.
• Plant-derived chemicals can control the biosynthetic capabilities of plant-associated microbes.
• These findings highlight potential eco-friendly strategies for agriculture by manipulating plant-microbe interactions.