A freezing responsive UDP-glycosyltransferase improves potato freezing tolerance via modifying flavonoid metabolism

Potato (Solanum tuberosum) is a globally important staple crop. However, cultivated potato varieties are highly sensitive to low temperatures. The molecular mechanisms underlying freezing resistance in potatoes remain poorly understood. Through comparative metabolome and transcriptome analyses of freezing-tolerant (CM, Solanum commersonii) and freezing-sensitive (DM, DM1-3516R44) varieties, we identified a cold-induced UDP-glycosyltransferase gene, ScUGT73B4, which is associated with the accumulation of glycosylated flavonoids in wild CM varieties. Overexpression of ScUGT73B4 led to increased accumulation of glycosylated flavonoids and enhanced antioxidant capacity, resulting in improved freezing tolerance in potato plantlets. These findings reveal a UDP-glycosyltransferase in the flavonoid pathway and offer a potential valuable genetic resource for breeding potatoes with improved freezing tolerance.