The effects of postharvest pre-treatments with para-coumaric acid (PCA) and cinnamic acid (CA) against brown blotch disease in Agaricus bisporus mushrooms caused by Pseudomonas tolaasii were investigated. PCA and CA at the concentration of 300 mg L−1 provided the highest inhibition ratio of 28.9% and 20.9%, respectively, on the in vitro growth of P. tolaasii. In addition, PCA and CA pre-treatments dramatically reduced the P. tolaasii-caused brown blotch disease in postharvest A. bisporus. Biochemical analysis revealed that PCA and CA inhibited P. tolaasii-induced activation of polyphenol oxidase and melanin production, increased activities of β-N-acetylglucosaminidase, β-1,3-glucanase and chitinase, promoted phenylpropanoid biosynthetic enzyme activities and metabolite production, enhanced antioxidant enzyme activities, and decreased malondialdehyde content in A. bisporus mushrooms. Collectively, these results demonstrated that PCA and CA can induce resistance to postharvest brown blotch disease in A. bisporus mushrooms, and have good prospects for disease control in edible mushrooms.
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