Ozone mitigates the flesh discoloration in response to 1-methylcyclopropene by promoting anthocyanin biosynthesis in postharvest nectarines

Abstract

The effects of combined treatments with 1-methylcyclopropene (1-MCP) and ethylene absorbent (EA) or ozone (O3) on the anthocyanins biosynthesis in nectarines stored at 0 °C were investigated during the storage period. The results indicated that 1-MCP+EA and 1-MCP+O3 effectively inhibited respiration and ethylene release. 1-MCP+EA reduced anthocyanins accumulation and inhibited the red coloration in pulp, whereas 1-MCP+O3 accelerated the red pigmentation. Contrasted to the 1-MCP group, 1-MCP+O3 exhibited higher anthocyanins contents, expression levels of PpPAL1, PpCHS, PpDFR, PpANS, PpUFGT, and PpMYB10.2 and activities of 4-coumarate coenzyme A ligase, flavanone 3-hydroxylase, dihydroflavonol 4-reductase, uridine diphosphate flavonoid 3-O-glucosyltransferase involved in the phenylpropanoid pathway. These results indicated that 1-MCP+O3 promoted the anthocyanins biosynthesis due to the up-regulation of enzymes activities and anthocyanins biosynthetic genes and transcription factor. This study may shed new light on improving quality and color development and optimizing 1-MCP application for postharvest preservation of fruit.