Thiamine cross-feeding drives microbial coexistence in the leaf microbiome.

Thiamine cross-feeding between yeast and oomycete promotes their stable coexistence in the leaf microbiome, with Dioszegia hungarica supplying thiamine to Albugo laibachii.

• Why it matters: Understanding microbial community stability is vital for host health and ecosystem function, but the molecular mechanisms behind community assembly are not well understood.
• What they did: A continental-scale survey identified an asymmetric mutualism where Dioszegia facilitates Albugo colonization by providing thiamine, supported by genomic and transcriptomic analyses, and validated through in planta assays.
• The result: This metabolic cooperation underpins microbial coexistence and microbiome stability, offering new avenues for engineering microbiomes and improving plant resilience through targeted nutrient flow manipulation.