Cross species metabolic complementation of vitamin K2 biosynthesis determines emergent suppression of tomato Fusarium wilt.

Multi-omics approaches have revealed a cross-species functional emergence phenomenon leading to emergent suppression of Fusarium wilt. We show that a three‑species consortium exhibits emergent suppression of Fusarium oxysporum f. sp. lycopersici (Fol) that is absent in single or pairwise cultures. This antifungal activity arises from coordinated activation of two phylogenetically distinct vitamin K2 biosynthesis pathways-the Men pathway (primarily Bacillus) and the Mqn pathway (Paenibacillus)-whose complementary actions enhance K2 production and directly inhibit the pathogen. A structural analogue, vitamin K3, recapitulates this effect, offering translational potential. Our findings establish that emergent microbiome functions depend on interaction‑triggered latent metabolic activation, not constitutive exchange or additive effects.