Chitosan and Pichia membranaefaciens control anthracnose by maintaining cell structural integrity of citrus fruit

This work evaluated effects of chitosan and Pichia membranaefaciens treatments on anthracnose control of cell membrane and cell wall structure in citrus fruit (Citrus sinensis L. Osbeck). Pathogen infection can cause cell membrane destruction and cell wall degradation. The disease incidence and lesion diameter on chitosan- and P. membranaefaciens- treated citrus was significantly reduced, especially P. membranaefaciens. Moreover, those treatments all could regulate reactive oxygen species (ROS) to induce defense system, control the cell membrane damage, increase phenylalanine ammonia-lyase (PAL) activity to accumulate lignin, reduce cell wall related enzymes activities (PG, PME, CEL) to maintain the cell wall related compounds (pectin, cellulose) to maintain cellular integrity. These results indicated that chitosan and P. membranaefaciens treatments can control Colletotrichum gloeosporioides in citrus fruit via the maintenance of host cell structure integrity.