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The effects of two oxylipins - jasmonic acid (JA) and 9, 10-ketol-octadecadienoic acid (KODA) - on ethylene metabolism and ethylene receptor genes were examined in peach fruit (Prunus persica L.) harvested at 88 days after full bloom (DAFB), in the pre-climacteric stage, and at 102 DAFB, at the beginning of the climacteric stage. Immediate post-harvest applications of either n-propyl dihydrojasmonate (PDJ) (a JA analog) or KODA stimulated ethylene production and 1-aminocyclopropane-1-carboxylate (ACC) concentrations in fruit that were harvested at 88 and 102 DAFB. KODA application significantly increased levels of ACC oxidase (PpACO1) expression at 5 and 8 days after treatment (DAT) in 88-DAFB-harvested fruit, and at 1 DAT in 102-DAFB-harvested fruit. Expression levels of ethylene response factors (PpERS1) were not influenced by either PDJ or KODA applications at 88 or 102 DAFB. In contrast, levels of ethylene-receptor-coding genes (PpETR1) expression in 88-DAFB KODA-treated fruit increased at 8 and 14 DAT. Expression levels of constitutive triple response (PpCTR1) in the untreated control fruit decreased with DAT in both 88- and 102-DAFB-harvested fruit. These results suggest that certain oxylipins may promote ethylene production in peach fruit, and that PpETR1 and PpCTR1 may be associated with the autocatalytic system of ethylene production. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the inhibitory effect of 1-pentylcyclopropene (1-PentCP), a structural analogue of 1-methylcyclopropene (1-MCP), on postharvest ripening and senescence of bananas fruit (Musa acuminataL. AAA group cv. Brazil). The results showed that 1-PentCP was effective in postponing the occurrence time of ethylene production peak and respiration rate peak, delaying the softening and color change, inhibiting the increasing of soluble solids, soluble sugar, and 1-aminocyclopropane-1-carboxylate acid (ACC) content; inhibiting the activities of ACC synthase (ACS) and ACC oxidase (ACO); and suppressing the expression ofMaERS1 andMaERF1 in bananas. In addition, 1.2μL/L 1-PentCP was found to be most effective in delaying ripening and senescence process of bananas by inhibiting the activities of enzymes involved in ethylene biosynthesis and gene expression of ethylene receptors. It is suggested that 1-PentCP could be a promising candidates for practical use as a given ethylene inhibitor applied before the onset of ethylene action. [ABSTRACT FROM PUBLISHER]