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Irregular ripening is a major deterrent for the purchase of European pears. Cell wall polyuronides and related- modifying enzymes were investigated in two European winter pears, ‘Comice’ and ‘d’Anjou’, during ripening at 20 °C following 5 and 8 months of storage at −1.1 °C. Both pear cultivars developed a melting (buttery-juicy) texture and higher water-soluble polyuronides (WSP) in flesh tissue after 5 months, but the pears’ texture quality decreased and a mealy (coarse-dry) texture presented in ‘Comice’ pear after long-term storage. Activities of pectin methylesterase (PME) and α-arabinofuranosidase (α-ARF) in ‘Comice’ pears was positively correlated with texture development, whereas in ‘d’Anjou’ pears polygalacturonase (PG), PME, cellulase (CEL), and β-galactosidase (β-GAL) were more highly correlated with texture. 1-MCP reduced pear ripening by inhibiting ethylene production and the activities of cell wall-modifying enzymes, maintaining higher antioxidants, and alleviating membrane lipid peroxidation. These results indicated melting texture developed in European pears as a result of the synthesis of WSP and increase of PME activity during pear fruit softening. [ABSTRACT FROM AUTHOR]

• Postharvest CO treatment effectively controlled Alternaria rot in jujube. • CO did not show any antifungal activity to A. alternata in vitro. • CO treatment enhanced the accumulation of antifungal substances. • CO activated disease resistance-related enzymes (PAL, PPO, CHI and GLU) in jujube. CO is a gas signal molecule involved in various physiological and metabolic regulation processes in plants. In the present study, we evaluated the effects of CO fumigation on the control of Alternaria rot in jujube fruit and explored the mechanism of action. Results showed that CO at 10 μmol L−1 significantly reduced lesion diameter in the fruit inoculated with A. alternata without showing any antifungal activity in vitro. CO treatment enhanced the activities of four representative resistance-related enzymes (phenylalanine ammonia-lyase, polyphenol oxidase, chitinase, and β-1,3-glucanase). Furthermore, CO also led to increase in the content of phenolics, flavonoids, lignin, and H 2 O 2. These results indicate that CO induces resistance to Alternaria rot primarily by activating disease resistance-related enzymes and enhancing accumulation of antifungal substances, and that CO can be a promising elicitor of plant defense responses to resist Alternaria rot in postharvest jujube fruit. [ABSTRACT FROM AUTHOR]