Ascorbate Biosynthesis and Recycling Genes Are Involved in the Responses of Garlic Allium sativum L. Plants to Fusarium proliferatum Infection

The expression profile of the key genes of biosynthesis (VTC2, GPP, GalDH, and GalLDH) and recycling (MDHAR1, MDHAR4, and MDHAR5) of ascorbate in response to infection with the fungal pathogen Fusarium proliferatum in garlic cultivars resistant (Podnebesny) and sensitive (Dubkovsky) to Fusarium rot was determined. It was found that differences in resistance to Fusarium lead to discrepancies in the dynamics and expression of individual genes of the ascorbate pathway, as well as in the ascorbate content. It was shown that, in response to infection, the expression level of the MDHAR4 gene increases in the resistant cultivar and decreases in the Fusarium-sensitive accession. As infection progresses, the expression levels of the VTC2 and GalLDH genes increase significantly (higher in the cv. Dubkovsky than in the cv. Podnebesny). In both cultivars, the ascorbate content increases (1.5 times higher in the cv. Dubkovsky than in the cv. Podnebesny).