MHO对苹果虎皮病发生和果皮活性氧代谢的影响

摘要

6-methyl-5-heptene-2 ketone (MHO) induced apple skin disease incidence and the skin effects of reactive oxygen species metabolism were investigated.Red Star apples of cold storage for 210 d were treated with 0.5,1.0 and 2.0 mL/L exogenous MHO.The content of endogenous MHO was after 10 d under 25 ℃,the malondialdehyde and superoxide anion radical and hydrogen peroxide contents in skin,and polyphenol oxidase,superoxide dismutase,catalase,peroxidaseenzyme activities were measured on a regular basis during the shelf life..Results showed that with the increase of MHO treatment concentration,the contents of malondialdehyde and superoxide anion radical and hydrogen peroxide in apple peel increased;Polyphenol oxidase activity gradually increased,superoxide dismutase,catalase,peroxidaseenzyme activities decreased with the increase of MHO treatment concentration; The endogenous MHO content increased and the incidence of skin disease of fruit also increased with the increase of MHO treatment concentration.So that exogenous MHO may reduce the onset of antioxidant enzyme activities to participate in apple skin disease process.%为研究6-甲基-5-庚烯-2酮(MHO)诱导苹果虎皮病发病以及对果皮活性氧代谢的影响,该实验将冷藏210d的红星苹果用0.5、1.0、2.0 mL/L的MHO进行外源处理后,测定其内源MHO含量,在25℃下放置10d后,期间定期测定货架期果皮中的MDA、O2-u0007、H2O2含量,以及PPO、SOD、CAT、POD活性的变化.结果表明,随着MHO处理浓度的增加,红星苹果果皮中MDA、O2-u0007、H2O2的含量也随之增加；果皮中的PPO活性逐渐上升,SOD、CAT、POD的活性随着MHO的处理浓度增加而降低；随着MHO处理浓度的增加,果实虎皮病的发病率也随之升高,同时果皮内源MHO含量也随之逐渐增加.研究认为,外源MHO可能通过降低抗氧化酶活性进而参与苹果虎皮病的发病过程.