Abstract. Coumarins are a family of plant-derived secondary metabolites that are produced via the phenylpropanoid pathway. In the past decade, coumarins ha

Arabidopsis coordinates Fe acquisition with its root microbiota by releasing distinct coumarin chemotypes in response to environmental pH. These root-exuded specialized metabolites interact with root-associated bacteria to mobilize Fe either through bacterial siderophore-dependent chelation at circumneutral pH or through bacterial redox-sensing-controlled reduction at acidic pH.

The plant microbiome plays a central role in regulating plant health and resilience, providing eco-friendly alternatives to agrochemicals. Plant-associated Streptomyces species are prolific producers of structurally diverse natural products with a demonstrated role in promoting plant growth. Coumarins are prevalent plant metabolites that shape the root microbiome, but their impact on microbial natural product biosynthesis is poorly understood. Here, we demonstrate that the coumarins scopoletin and its glucoside scopolin remodel specialized metabolism in the Arabidopsis root endophyte Streptomyces sp. ATMOS53. Multiomics analyses revealed that the coumarins activate the biosynthesis of the pyrrolizidine alkaloids bohemamines and alter the balance in anthracycline biosynthesis, with reduced production of late-stage anthracycline congeners and accumulation of shunt metabolites earlier in the pathway. These metabolic shifts resulted in a marked reduction of the antimicrobial activity of ATMOS53 against plant-associated Bacillus and Paenibacillus species. Notably, coumarin-mediated repression of anthracycline production was also observed in the established producers Streptomyces peucetius and Streptomyces galilaeus, indicating that the regulatory effect on anthracycline biosynthesis is conserved in streptomycetes. Our findings highlight coumarins as modulators of specialized metabolism of Streptomyces and show the significance of plant-derived chemicals for the control of the biosynthetic capacity of plant-associated microbes.

Arabidopsis coordinates Fe acquisition with its root microbiota by releasing distinct coumarin chemotypes in response to environmental pH. These root-exuded specialized metabolites interact with root-...

Iron acquisition is a critical challenge for plants, especially in iron-deficient soils. Recent research underscores the importance of root-exuded coumarins in modulating the root microbiome communi.....

Iron acquisition is a critical challenge for plants, especially in iron-deficient soils. Recent research underscores the importance of root-exuded coumarins in modulating the root microbiome community...

Complex coumarins (CCs) represent characteristic metabolites found in Apiaceae plants, possessing significant medical value. Their essential functional role is likely as protectants against pathogens and regulators responding to environmental stimuli. Utilizing genomes and transcriptomes from 34 Apiaceae plants, including our recently sequenced Peucedanum praeruptorum, we conduct comprehensive phylogenetic analyses to reconstruct the detailed evolutionary process of the CC biosynthetic pathway in Apiaceae. Our results show that three key enzymes – p-coumaroyl CoA 2’-hydroxylase (C2’H), C-prenyltransferase (C-PT), and cyclase – originated successively at different evolutionary nodes within Apiaceae through various means of gene duplications: ectopic and tandem duplications. Neofunctionalization endows these enzymes with novel functions necessary for CC biosynthesis, thus completing the pathway. Candidate genes are cloned for heterologous expression and subjected to in vitro enzymatic as

.50% ± 0.92% yield. Qualitative and quantitative phytochemical analysis of the extract revealed the presence of alkaloids, flavonoids, phenols, steroids, terpenoids, coumarins, and carbohydrates, with...

Here, the authors show that rhizobacteria can utilize and detoxify simple coumarins secreted by iron-deficient plants, thereby enhancing their root colonization. This, in turn, hampers plant iron acqu...