The Effect of 1-MCP on the Expression of Several Ripening-related Genes in Strawberries

Abstract

To elucidate the role of ethylene in nonclimacteric fruit development and ripening, quantitative (cDNA–amplified fragment length polymorphism) cDNA–AFLP was used to visualize differential gene expression in four stages of ripening of strawberries (Fragaria×ananassa Duch. `Elsanta') treated with 1-methylcyclopropene (1-MCP), a competitive inhibitor of ethylene action. The proportion of clones affected by 1-MCP treatment was much higher in green than in white, pink, and red receptacle tissue. Three major cell-wall-related genes were affected by 1-MCP and, thus, are putatively ethylene dependent: a ripening-repressed beta-galactosidase (Faßgal3), up-regulated by 1-MCP; a putative endo-1,3-1,4-beta-D-glucanase (EGase), up-regulated in green and down-regulated in red fruit by 1-MCP; and a pectate lyase B (plB), expressed only in the red stage and significantly down-regulated by 1-MCP. Furthermore, we have identified genes encoding an alcohol dehydrogenase, a protein kinase-related protein, and a putative glutathione S-transferase, all ripening-induced and down-regulated by 1-MCP, suggesting that their regulation is at least partly ethylene dependent.