Yeast cell wall induces disease resistance against Penicillium expansum in pear fruit and the possible mechanisms involved.

The results from this study showed that cell wall prepared from Rhodosporidium paludigenum induced strong disease resistance against blue mold rot caused by Penicillium expansum in pear fruit. Yeast cell wall reduced germination of P. expansum in vitro and in fruit wounds after 24h of treatment. Moreover, the cell wall treatment significantly enhanced the activities of defense-related enzymes (β-1,3-glucanase and chitinase) and the genes expression of PR proteins (PR1-like, endoGLU9, endoCHI-like and PR4), which may be an important mechanism by which cell wall reduces the fungal disease of pear fruit caused by P. expansum. These findings suggest that the mechanism by which R. paludigenum induced fruit resistance was linked to the function of its cell wall and application of cell wall might be a useful strategy for the control of postharvest disease in pear fruit.