外源褪黑素通过调控活性氧代谢减轻采后杏果实冷害

为探究褪黑素处理对杏果实采后冷害和活性氧(reactive oxygen species,ROS)代谢的影响,本研究以'赛买提'杏为材料,采用不同浓度(50、100、200μmol/L)的褪黑素进行减压渗透处理(0.05?MPa保持2 min,后恢复常压继续浸泡8 min),以蒸馏水处理作对照,处理后的杏果实置于温度(...

Exogenous Melatonin Ameliorates Postharvest Chilling Injury of Apricot Fruit by Modulating Reactive Oxygen Species Metabolism

In this study, the effects of melatonin on chilling injury and reactive oxygen metabolism were investigated during the storage of postharvest apricot fruit at (0 ± 1) ℃ and 90%–95% relative humidity. ‘Saimaiti’ apricots were impregnated with different concentrations of melatonin (50, 100 and 200 μmol/L) at 0.05 MPa for 2 min and then at atmospheric pressure for 8 min before storage. Distilled water was used as a control. Chilling injury incidence and chilling injury index were periodically recorded, and malondialdehyde (MDA) content, cell membrane permeability, superoxide anion radical production rate, H2O2 content and antioxidant enzyme activities were measured in apricot fruit. Compared to the control group, melatonin treatment obviously reduced chilling injury incidence and index in apricot fruit (P < 0.05), and 100 μmol/L melatonin was the most effective in reducing chilling injury. Furthermore, apricot fruit treated with melatonin increased the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD), inhibited the accumulation of superoxide anion radical and H2O2, reduced membrane lipid peroxidation, and maintained membrane integrity. These results suggested that the inhibition of exogenous melatonin on chilling injury of apricot fruit was closely related to the regulation of reactive oxygen metabolism. These findings can provide a theoretical basis for the application of melatonin in controlling chilling injury of postharvest apricot fruit.