Influences of flavonoids from Sedum aizoon L. on the cell membrane of Botrytis cinerea

Botrytis cinerea is a plant pathogen, which affects the quality of fruits. However, chemical antifungal agents are extremely harmful to the environment, hence it's critical to create a natural plant-derived antifungal agent to replace chemical antifungal agents. The study explored the antifungal mechanisms of flavonoids from Sedum aizoon L. (FSAL) against B. cinerea. In the study, cell membrane served as an important breakthrough point. The minimum inhibitory concentration (MIC) of FSAL against B. cinerea was investigated. The propidium iodide (PI) staining observation of B. cinerea was explored. The activities of crucial enzymes involved in the metabolism were studied as well as the phospholipid and fatty acid changes. The expression of genes related to the membrane lipid metabolism was also measured. The results showed that FSAL had a certain inhibitory effect on B. cinerea and the MIC was 1.500 mg/mL. FSAL disrupted the cell membrane of B. cinerea, which decreased the contents of glutathione and proline at a low level as well as the membrane phospholipids. Compared with the control group, the activities of crucial enzymes were decreased, and the expression of key genes was reduced. It indicated that FSAL inhibited B. cinerea by disrupting its cell membrane, offering the possibility of a natural plant-derived antifungal agent for the preservation of fruits.