外源乙烯和茉莉酸甲酯对鲜切甘蓝活性氧代谢的影响

为研究鲜切果蔬活性氧代谢以及不同外源信号分子对鲜切果蔬活性氧代谢的影响,以鲜切甘蓝为材料,利用外源乙烯和茉莉酸甲酯（MeJA）处理鲜切甘蓝,于4℃条件下贮藏,测定了活性氧H2O2和O2-·的变化,超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）以及抗坏血酸过氧化物酶（APX）等酶活性。结果表明,乙烯和MeJA两种处理抑制了鲜切甘蓝活性氧H2O2含量的增加及O2-·的生成速率,外源乙烯处理提高了鲜切甘蓝中具有防御功能的SOD和APX活性,而抑制了POD和CAT的活性;MeJA处理后鲜切甘蓝的SOD、POD、CAT活性均受到抑制,对整个贮藏过程中的APX活性的作用效果有所不同,贮藏前期促进但贮藏后期起到一定程度的抑制作用。在两种处理中,乙烯提高鲜切甘蓝的抗氧化活性作用明显。 

Effect of exogenous ethylene and methyl jasmonate (MeJA) on reactive oxygen metabolism in tissue of fresh-cut cabbage

To clarify the reactive oxygen metabolism of fresh-cut fruits and vegetables, fresh-cut cabbages were taken as materials, exogenous ethylene and methyl jasmonate (MeJA) were used as signals to treat fresh-cut cabbages, and then stored at 4℃. The changes of H2O2 and O2-were analyzed and the activity of super oxygen dehydrogenises (SOD) , peroxidase (POD) , catalase (CAT) , ascorbate peroxidase (APX) were measured as main enzymes in the metabolism. Results showed that the reactive oxygen including H2O2 and O2-were inhibited by ethylene and MeJA respectively. The activity of SOD and APX could be improved after treated with ethylene, but the activity of POD and CAT were inhibited. Antioxidant enzymes including SOD, POD, and CAT were inhibited after MeJA treatments. The influence of MeJA on APX during 12h were different, the activity of APX was promoted in the beginning but inhibited in the end. Between two treatments, ethylene could promote the antioxidant activity of fresh-cut cabbage obviously.