Chemical dialogues at the crossroads of host–bacteria interactions Microbiomes are now recognised as the second genome of eukaryotes, providing diverse life-support functions for their hosts. The impact of microbiome members on the growth and health of their hosts is...

Chemical dialogues at the crossroads of host–bacteria interactions

@cp-trendsplantsci.bsky.social by Emtinan Diab, Nicola Thome, Somayah Elsayed, @raaijmakersjm.bsky.social and @gillesvanwezel.bsky.social

www.cell.com/trends/micro...

panorama of Haarlem (aka home)

Panorama of Haarlem (aka home)

Now out in @acs.org JACS Au, the manuscript by #BarbaraTerlouw et al. describing PARAS, a high-accuracy machine-learning algorithm to predict substrate specificities of nonribosomal peptide synthetase (NRPS) adenylation domains, key for estimating natural product structures from BGC sequence. 1/n

awesome, thanks!

Graphical abstract Diab (2026)

New publication: Plant Coumarins #Modulate Natural Product #Biosynthesis in a #Streptomyces #Root #Endophyte, by @gillesvanwezel.bsky.social and others.
doi.org/10.1021/acs....

if Iran gets a nuclear weapon, Israel will be gone the next day and then the world follows. When to intervene and on what legal basis I cannot judge. But friendly talks and common sense will never help. Wish we could solve it with a nice scientific debate but...

Bluesky is mostly science for me. Anyway, Iran murdered as many civilians in 2 days as fell in Gaza in 2 years. It does not legitamise war, but the silence after the brutal genocide in Iran shows how focused and the West is on Israel. Let's hope the world will become a better place soon.

Plant Coumarins Modulate Natural Product Biosynthesis in a Streptomyces Root Endophyte 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.

Plant Coumarins Modulate Natural Product Biosynthesis in a Streptomyces Root Endophyte

Journal of Natural Products by Emtinan Diab, Chao Du, Wendalina Tigani, Somayah Elsayed and @gillesvanwezel.bsky.social #LeidenBiology

pubs.acs.org/doi/10.1021/...

@gillesvanwezel.bsky.social @marnixmedema.bsky.social @lonegram.bsky.social @medinadiscovery.bsky.social @aberdeenchem.bsky.social @cleverflick.bsky.social @erinninnovation.bsky.social @naturalis.bsky.social @wurplant.bsky.social @bahnestechmann.bsky.social @eu-openscreen.bsky.social @ethz.ch

Genes for the biosynthesis of plant natural products are clustered on plants, as discussrd (and published) by @anneosbourn.bsky.social

talk is also enjoyed by @evolvedbiofilm.bsky.social 🙂

looking forward to the talk by @anneosbourn.bsky.social on Plant Natural Products and esp triterpenes. Anne is todays speaker in the @led3hub.bsky.social seminar series.

great post, thanks.

2025 was a year full of great scientific discoveries and breakthroughs. Here, I want to highlight 10 papers that got me really excited. Of course, this is a highly subjective selection and I am sure I am forgetting some papers that I would love to include, but here it goes: (1/12)

last walk of the year in parc Elswout.

Graphical abstract Pan et al. (2026).

New publication: Disentangling the molecular mechanisms of disease suppression by endophytic #Flavobacterium sp. 98, by @xinyapan.bsky.social @gillesvanwezel.bsky.social @raaijmakersjm.bsky.social and others. #plantmicrobiome #plantgrowth
doi.org/10.1016/j.mi...

Kudos to #yijunzhu #hannahaugustijn and #victoriapascal for getting this out, and thanks to @gillesvanwezel.bsky.social #dylandodd and #michaelfischbach for the collaboration!
Try it out now on gutsmash.bioinformatics.nl

congrats Xinya. Thanks for involving us in this great piece of work!

Hypoxia Induces Phenotypic and Metabolic Shifts in Endophytic Flavobacterium sp. 98 Abstract. Oxygen plays a crucial role in shaping microbial physiology, functions, and behavior. Endophytic bacteria, residing within plant tissues, inhabit

academic.oup.com/ismej/advanc... Endophytic adaptation in Flavobacterium sp. 98 @xinyapan.bsky.social @vcarryon.bsky.social @gillesvanwezel.bsky.social ✌🏽 lysoPE story could be cool

admittedly it was for a PhD defense act...

Endozoi què?

keep trying

ja die loting.... sloeg helemaal nergens op. Die vredesprijs voor Trump ook, absurd.

de bezuinigingen zijn idd (deels) debatable. Qua programma's, de omroepen krijgen budget en maken zelf de keuzes en die zijn heel interessant. Programma's die populair zijn gaan naar de commercielen. De culturele programma's delven wellicht het onderspit. Daar moet je goed naar kijken.

Enrichment of root-associated Streptomyces strains in response to drought is driven by diverse functional traits and does not predict beneficial effects on plant growth Understanding how root microbes respond to drought is crucial for improving crop resilience. This study finds that Streptomyces responses are strain-specific and functionally diverse, with traits and ...

Enrichment of root-associated Streptomyces strains in response to drought is driven by diverse functional traits and does not predict beneficial effects on plant growth

journals.plos.org/plosbiology/...

Top: (Top row) Sensitivity of S. coelicolor mutants to GlcNAc. Spores (5 × 105 CFU) of S. coelicolor M145 and its mutant derivatives ∆nagB, SMA11, ∆nagB∆nagS, ∆nagB∆nagSC (∆nagB∆nagS expressing nagS) and ∆nagB∆nagSE (∆nagB∆nagS with empty plasmid pSET152) were streaked on MM agar plates with 1% mannitol (Mann) and 1% mannitol plus 10 mM GlcNAc (GlcNAc). (Bottom row) NagS and its role in GlcNAc sensing. Spores of M145 and ∆nagS were plated on MM and R5 with 0, 0.001, 0.01, 0.1, 1, 5, 10, 20, 50, 100, 150, and 200 mM GlcNAc. Note that nagS mutants hardly respond to GlcNAc. Bottom: Model for the metabolic control of development by GlcNAc and NagS. During late vegetative growth of streptomycetes, the old vegetative or substrate hyphae are degraded in a process of programmed cell death (PCD), to produce the nutrients required to build the aerial mycelium (see mycelial drawings on the right). Mycelial lysis results in breakdown of the cell-wall, leading to the accumulation of GlcNAc-6P, which is a major nutritional signal for the onset of development and antibiotic production. NagS converts GlcNAc-6P into 6P-chromogen I (denoted as X-Ac-6P), which in turn is deacetylated by NagA into a toxic metabolite (denoted as X-6P) that resembles ribose. The toxic metabolite promotes cell lysis, thus releasing more GlcNAc-6P that serves as substrate for NagS and NagA. A salvage pathway then switches off the toxic pathway again. For this, GlcNAc-6P is converted by NagA and NagB into Fructose-6P (Fru-6P), which enters the pentose phosphate pathway (PPP), thereby producing 6-phosphogluconate (6-PG), a metabolic inhibitor of NagS. Thus, production of toxic metabolites ceases and the transition to aerial growth can be initiated. Arrows with round ends represent inhibition, dashed arrow shows proposed activity.

GlcNAc build-up acts as a key metabolic signal in #Streptomyces, but how does it triggers developmental responses? @gillesvanwezel.bsky.social &co show that the enzyme NagS dehydrates GlcNAc-6P into a reactive intermediate, triggering a toxicity-based checkpoint @plosbiology.org 🧪 plos.io/44pE08I

say hi!

thanks @angelahuttner.bsky.social for a very inspiring talk LUMC Leiden.
The house in the image you showex was built in 1612, and Rembrandt van Rhijn was 6 years old by then and lived at the bridge in the back, 200 m away. Always when I see the house I think of how Rembrandt will have painted it!

@lennartschada.bsky.social

Top: (Top row) Sensitivity of S. coelicolor mutants to GlcNAc. Spores (5 × 105 CFU) of S. coelicolor M145 and its mutant derivatives ∆nagB, SMA11, ∆nagB∆nagS, ∆nagB∆nagSC (∆nagB∆nagS expressing nagS) and ∆nagB∆nagSE (∆nagB∆nagS with empty plasmid pSET152) were streaked on MM agar plates with 1% mannitol (Mann) and 1% mannitol plus 10 mM GlcNAc (GlcNAc). (Bottom row) NagS and its role in GlcNAc sensing. Spores of M145 and ∆nagS were plated on MM and R5 with 0, 0.001, 0.01, 0.1, 1, 5, 10, 20, 50, 100, 150, and 200 mM GlcNAc. Note that nagS mutants hardly respond to GlcNAc. Bottom: Model for the metabolic control of development by GlcNAc and NagS. During late vegetative growth of streptomycetes, the old vegetative or substrate hyphae are degraded in a process of programmed cell death (PCD), to produce the nutrients required to build the aerial mycelium (see mycelial drawings on the right). Mycelial lysis results in breakdown of the cell-wall, leading to the accumulation of GlcNAc-6P, which is a major nutritional signal for the onset of development and antibiotic production. NagS converts GlcNAc-6P into 6P-chromogen I (denoted as X-Ac-6P), which in turn is deacetylated by NagA into a toxic metabolite (denoted as X-6P) that resembles ribose. The toxic metabolite promotes cell lysis, thus releasing more GlcNAc-6P that serves as substrate for NagS and NagA. A salvage pathway then switches off the toxic pathway again. For this, GlcNAc-6P is converted by NagA and NagB into Fructose-6P (Fru-6P), which enters the pentose phosphate pathway (PPP), thereby producing 6-phosphogluconate (6-PG), a metabolic inhibitor of NagS. Thus, production of toxic metabolites ceases and the transition to aerial growth can be initiated. Arrows with round ends represent inhibition, dashed arrow shows proposed activity.

GlcNAc build-up acts as a key metabolic signal in #Streptomyces, but how does it triggers developmental responses? @gillesvanwezel.bsky.social &co show that the enzyme NagS dehydrates GlcNAc-6P into a reactive intermediate, triggering a toxicity-based checkpoint @plosbiology.org 🧪 plos.io/44pE08I