Fumonisin B1 induces nuclease activation and salicylic acid accumulation through long-chain sphingoid base build-up in germinating maize

Fusarium verticillioides is a predominant maize fungal pathogen that causes seed decay, damping-off and seedling blight. Most isolates of this fungus produce fumonisins, which disrupt sphingolipid biosynthesis causing the accumulation of sphingoid long-chain bases (LCB). In the work reported in this paper we tested the effect of fumonisin B1 (FB1) on germinating maize embryos and found that it induced an endonuclease activity and salicylic acid (SA) accumulation that correlate with sphingoid LCB build-up and cell lysis. Exogenously applied sphinganine produced similar effects on these markers. This suggests that fumonisin production contributes to the colonization of this necrotroph by activating the SA pathway and inducing cell death.