Progress on physiological and molecular mechanisms of storage root formation and development in sweetpotato

Sweetpotato (Ipomoea batatas (L.) Lam.) is an important food crop worldwide. The storage root is undisputedly the most vital agronomic trait and the main harvest goal in sweetpotato production. Therefore, exploring the mechanisms underlying the storage root formation and development is of particular importance. Storage root formation and development are complex biological processes, involving in morphological, physiological and molecular changes. Morphologically, storage root formation and bulking is the result of cell division and cam-bium activity. Physiologically, storage root formation and bulking is affected by a variety of hormonal signals. Genetically, storage root formation and bulking is regulated by a large number of genes, proteins and enzymes. This review summarizes the morphological, physiological and molecular changes during storage root formation and bulking and provides future directions for the study of sweetpotato storage root formation and development.