Methyl jasmonate differentially and tissue-specifically regulated the expression of arginine catabolism-related genes and proteins in Agaricus bisporus mushrooms during storage.

Methyl jasmonate (MeJA)-regulated postharvest quality retention of Agaricus bisporus fruiting bodies is associated with arginine catabolism. However, the mechanism of MeJA-regulated arginine catabolism in edible mushrooms is still unclear. This study aimed to investigate the regulatory modes of MeJA on the expression of arginine catabolism-related genes and proteins in intact and different tissues of A. bisporus mushrooms during storage. Results showed that exogenous MeJA treatment activated endogenous JA biosynthesis in A. bisporus mushrooms, and differentially and tissue-specifically regulated the expression of arginine catabolism-related genes (AbARG, AbODC, AbSPE-SDH, AbSPDS, AbSAMDC, and AbASL) and proteins (AbARG, AbSPE-SDH, AbASL, and AbASS). MeJA caused no significant change in AbASS expression but resulted in a dramatic increase in AbASS protein level. Neither the expression of the AbSAMS gene nor the AbSAMS protein was conspicuously altered upon MeJA treatment. Additionally, MeJA reduced the contents of arginine and ornithine and induced the accumulation of free putrescine and spermidine, which was closely correlated with MeJA-regulated arginine catabolism-related genes and proteins. Hence, the results suggested that the differential and tissue-specific regulation of arginine catabolism-related genes and proteins by MeJA contributed to their selective involvement in the postharvest continuing development and quality retention of button mushrooms.