Combined Benzothiadiazole and Heat Shock Treatment Accelerates Wound Healing in Sweet Potatoes

Mechanical damage resulting from the harvesting process and subsequent handling can contribute to the deterioration and decay of sweet potatoes (Ipomoea batatas) throughout storage. These detrimental effects can be mitigated by wound healing process. This study investigated the effects of combined benzothiadiazole (BTH) and heat shock (HS) treatment on the wound healing activity of sweet potatoes, along with the underlying mechanisms. Sweet potatoes subjected to BTH + HS treatment showed increased lignin formation and more hardness in the healing tissues than those individually treated with BTH or HS. The BTH + HS treatment surpassed each other in preventing weight loss, augmenting total phenolic and flavonoid compound production, and promoting reactive oxygen species (ROS) formation. In line with these results, the activity levels of enzymes associated with the phenylpropanoid pathway (phenylalanine ammonia-lyase, cinnamic acid 4-hydroxylase, 4-coumarate-CoA ligase, and cinnamyl alcohol dehydrogenase) and ROS metabolism (NADPH-dependent oxidases, superoxide dismutase, catalase, and peroxidase) were also enhanced to a greater degree in response to BTH + HS treatment relative to BTH or HS alone. Combining BTH and HS treatment is a more efficacious approach to improve sweet potato wound healing, with these benefits closely linked to the activation of the phenylpropanoid pathway and ROS metabolism.