Physiological changes and molecular regulation in sweetpotato responses to low-temperature stress

Sweetpotato (Ipomoea batatas [L.] Lam) is highly adaptable to different soils and climates, but it is more sensitive to cold due to its tropical origin. Low-temperature stress is a key factor affecting storage and has a significant impact on sweetpotato quality. During sweetpotato storage, prolonged exposure to low temperatures causes chilling damage to the root system, altering its physiological functions. This is manifested by wilting of the tuberous roots, nutrient loss, and reduced antioxidant enzyme activity. At the same time, it leads to a significant downregulation of genes associated with cold signaling pathways. Understanding the physiological and molecular mechanisms of sweetpotato's response to low-temperature stress, which is crucial for improving its quality during storage. In addition, methods such as high-voltage alternating electric field, controlled atmosphere, hot water treatment, and hot air treatment can better preserve the nutrients of sweetpotato and maintain their high commercial quality during low-temperature storage. This article reviews and summarizes key studies on the nutrient and physiological changes, as well as the molecular regulatory mechanisms of sweetpotato during low-temperature storage, and identifies unresolved questions in this field. It provides insights for further research on low-temperature stress in sweetpotato.