Pseudomonas siderophores: A mechanism explaining disease-suppressive soils

These findings suggest that disease suppressiveness is caused in part by microbial siderophores which efficiently complex iron(III) in soils, making it unavailable to pathogens, thus inhibiting their growth.

Abstract

The addition of either fluorescentPseudomonas strain B10, isolated from a take-all suppressive soil, or its siderophore, pseudobactin, to bothFusarium-wilt and take-all conducive soils inoculated withFusarium oxysporum f. sp.lini orGaeumannomyces graminis var.tritici, respectively, rendered them disease suppressive. Our findings suggest that disease suppressiveness is caused in part by microbial siderophores which efficiently complex iron(III) in soils, making it unavailable to pathogens, thus inhibiting their growth. Amendment of exogenous iron(III) to disease-suppressive soils converted them to conductive soils presumably by repressing siderophore production.