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

- Yeast cell wall inhibited the mold rot in harvested fruit for the first time.
- Yeast cell wall inhibited the spore germination of P. expansum in vitro.
- Yeast cell wall enhanced the activities of β-1,3-glucanase and chitinase.
- Yeast cell wall significantly up-regulated genes expression of PR proteins.

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 24 h 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.