Effect of 1-MCP Treatment on Postharvest Browning and Chlorophyll Breakdown Pathway Related Genes in Grape Rachis

The effects of 1-MCP on postharvest rachis quality, chloroplast ultrastructure and chlorophyll breakdown pathway genes expression were analyzed in the'Kyoho'table grape variety. The results showed that rachises treated with 1.0 μL/L 1-MCP had lower respiratory intensity and browning index, and higher tissue water content, soluble sugar content, lightness, greenness and chlorophyll content than the control, in contrast to the samples treated with 100 μL/L ethylene.Additionally, the expression of all known genes involved in the chlorophyll breakdown pathway was examined by real-time qPCR.The transcript abundance of non-yellow colouring 1 (NYC1), 7-hydroxymethyl chl a reductase (HCAR), pheophorbide a oxygenase (PAO), and stay-green 1 (SGR1) genes was inhibited by 1-MCP treatment, whereas that of NYC1-like (NOL).In conclusion, 1.0 μL/L 1-MCP could maintain rachis quality, delay rachis browning by suppressing the expression of some genes associated with the chlorophyll breakdown pathway, and maintain the integrity of chloroplasts in the grape rachis.