Building a Protective Shield: The Role of Wound Healing in Reducing Postharvest Decay and Preserving Quality of Citrus Fruit

Postharvest citrus fruit is susceptible to pathogenic infestation and quality reduction through wounds, leading to tremendous commercial losses. Herein, wound healing of citrus fruit was obviously at 25°C for five days to form a barrier effective against the development of infectious diseases and water dissipation. Combined with the results of transcriptional and metabolic levels, wound healing activated the expression of CsKCS4, CsKCS11, CsCYP704B1, CsFAH1, CsGPAT3 and CsGPAT9 genes in suberin biosynthesis pathway, and CsPMEI7, CsCesA-D3, CsXTH2, CsXTH6, CsXTH22, CsXTH23, CsXTH24, CsC4H and CsCAD genes in cell wall metabolism pathway, leading to the accumulation of suberin monomers and cell wall components. The results of microscopic observations proved wound healing promoted suberin deposition and cell wall strengthening. Meanwhile, wound healing required the provision of energy and precursor substances by carbohydrate metabolism and amino acid metabolism. We provide new insights into the regulatory mechanism of wound healing on improving disease resistance and maintaining the quality of citrus fruit.