2011 Volume 80 Issue 4 Pages 512-520
The effects of 1-methylcyclopropene (1-MCP) on ascorbate (AsA) metabolism were studied and the possible molecular mechanisms were discussed for two cultivars of cauliflower (Brassica oleracea, L. var. botrytis), ‘Violet Queen’ and ‘Snow Crown’. Ethylene production was suppressed in ‘Violet Queen’, while it was increased in ‘Snow Crown’ by 1-MCP treatment. Meanwhile, the changing patterns of AsA metabolism after harvest were different between the two cauliflower cultivars. In ‘Violet Queen’, AsA content decreased in the control after harvest, and the loss of AsA was delayed by 1-MCP treatment. In ‘Snow Crown’, AsA content remained almost constant and was not affected by 1-MCP treatment. In ‘Violet Queen’, the gene expression of BO-APX1, BO-APX2, and BO-sAPX was down-regulated, while the gene expression of BO-DHAR and BO-GLDH was up-regulated by 1-MCP treatment. The regulation of these genes contributed to the suppression of AsA reduction in ‘Violet Queen’ treated by 1-MCP. In ‘Snow Crown’, simultaneous down-regulation of BO-APX1, BO-APX2, and BO-sAPX, which were responsible for AsA breakdown, and BO-MDAR1, BO-MDAR2, BO-DHAR, and BO-GLDH, which were responsible for AsA regeneration and biosynthesis, might lead to maintain the AsA level constant with 1-MCP treatment.
