Wound healing in citrus fruit is promoted by chitosan and Pichia membranaefaciens as a resistance mechanism against Colletotrichum gloeosporioides

Colletotrichum gloeosporioides is the most important pathogen of citrus fruit and is a serious concern in rainy, humid regions and seasons. In this study, the effects of chitosan and Pichia membranaefaciens on anthracnose control, wound healing, and the cell wall changes in citrus fruit and the relationship between wound healing and cell wall composition were evaluated. We found that chitosan and P. membranaefaciens increased the wound healing process via wound tissue appearance changes, lignin accumulation, increases in cell wall compounds (pectin, cellulose) and reduced activities of cell wall enzymes - polygalacturonase (PG); pectin methylesterase (PME); cellulase (CEL) - to control anthracnose. During wound healing, acid-soluble pectin (ASP) and cellulose had strong positive correlations with lignin.