Analysis of the expression of genes related to oxylipin biosynthesis in Fusarium verticillioides and maize kernels during their interaction

Fusarium verticillioides is a pathogen that can cause ear and stalk rot in maize. Under suitable environmental conditions, this fungus produces large amount of fumonisins, a potential carcinogenic to humans and animals classified as IARC2B. Recent studies have shown that pathogen and host exchange an oxylipin-based cross talk during their interaction. This study was aimed at investigating whether environmental conditions, namely water activity (a(w)) at 0.90 and 20 degrees C, which are the thresholds for F. verticillioides development, affect the maize/fungal oxylipin gene expression profile. Fungal Fvlds1-3, Fvlox, Zmlox3 and the maize defense-related ZmPR1 genes significantly changed their expression after infection at 0.90 a(w) and 20 degrees C. Moreover, the expression of maize genes peaked after that of fungal genes, indicating that, under these experimental conditions, plant and pathogen coordinate the oxylipin gene expression reciprocally. This kind of modulation of fungal and plant gene expression is suggestive of the "zig zag model" proposed for other plant-pathogen interaction systems.