[Research advances on the metabolic pathways and functions mediated by plant xanthine dehydrogenase]

The xanthine dehydrogenase (XDH), a molybdenum-containing oxidoreductase belonging to the molybdenum hydroxylase flavoprotein family, has been identified in a variety of eukaryotes, bacteria, and archaea. XDH catalyzes the conversion of xanthine and hypoxanthine to uric acid, which then undergoes further reactions to form allantoin and allantoic acid. Studies have shown that XDH plays a role in various metabolic processes, including purine metabolism, nitrogen metabolism, hormone metabolism, reactive oxygen species metabolism, and responses to biotic and abiotic stresses. Here, we introduced the structural features, metabolic pathways, and biological functions of XDH. In addition, we summarized the research progress in XDH to give insights into the molecular mechanism of purine metabolism in plants and prospected the application of XDH, with the aim to facilitate future research on the growth, development, and stress resistance of crops.