Potential Role and Involvement of Antioxidants and Other Secondary Metabolites of Wheat in the Infection Process and Resistance to Fusarium spp.

Abstract

This article provides a summary of current knowledge about wheat metabolites that may affect resistance against Fusarium head blight (FHB). The mechanisms of resistance, the roles of secondary metabolites in wheat defense, and future directions for breeding are assessed. The soluble phenols play an important role in redox regulation in plant tissues and can act as antimicrobial compounds. The color of cereal hulls and grains is caused by such natural pigments as anthocyanins in the aleurone, endosperm, and pericarp layers of the grain. Phenolic acids, alkylresorcinols, and phytohormones actively participate in the defense system, whereas carotenoids show various effects against Fusarium species that are positively correlated with the levels of their mycotoxins. Pathogen infestation of vegetative tissues induces volatile organic compounds production, which can provide defensive functions to infested wheat. The efficient use of native resistance in the wheat gene pool, introgression of resistant alleles, and implementation of modern genotypic strategies to increase levels of native secondary metabolites with antifungal properties can enhance the FHB resistance of new varieties. Expanding the breeding interest in the use of forms with different grain color and plant organs can be a potential benefit for the creation of lines with increased resistance to various stresses.