Mechanism of Acetophenone Fumigation to Inhibit Postharvest Botrytis cinerea in Grape

Gray mold is one of the main diseases in postharvest storage of grape. To explore the inhibition mechanism of acetophenone fumigation on Botrytis cinerea. When acetophenone was the lowest fungistatic concentration, the morphology and structure of the hypha of B. cinerea were observed by electron microscope. The contents of lipid and fatty acid of B. cinerea were determined by liquid chromatography-mass spectrometry, and the fumigation control effect of acetophenone on B. cinerea was also tested. The results showed that the minimum inhibitory concentratio (MIC) of acetophenone fumigation for B. cinerea was 62.50 μL/L. In vivo, the lesion diameter of the control group was 2.58 times that of the MIC acetophenone treatment group (P<0.05), while no symptoms were observed in the 2×MIC acetophenone treatment group. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that the mycelial morphology of B. cinerea fumigated with acetophenone was rough, shrimpy, empty cell, reduced cytoplasmic matrix, and local plasmic wall separation. The morphology and structure of the control group were normal. Compared with the control group, after acetophenone fumigation, the levels of Cer in the lipids were significantly up-regulated, while the levels of phospholipids (PE, LBPA, PS, CL, PA) were significantly down regulated. According to the KEGG Pathway enrichment analysis, the AGE-RAGE signaling pathway and sphingolipid metabolism showed significant differences. There were 22 different fatty acids between the acetophenone fumigation group and the control group, 10 up-regulated and 12 down-regulated fatty acids, respectively. Acetophenone fumigation can destroy the morphology and structure of B. cinerea, control lipid synthesis by affecting sphingolipid metabolism and fatty acids, and inhibit the growth of B. cinerea both in vivo and in vitro. This study provides a theoretical basis for the development of fumigants for the control of postharvest gray mold in grape.