一氧化氮处理对甜瓜果实采后病害的控制及活性氧代谢的作用

Control of Post-harvest Diseases and Potentiation of Metabolism of Reactive Oxygen Species in Post-harvest Muskmelons Treated by Nitric Oxide

摘要:

为探究一氧化氮处理对甜瓜果实采后病害的控制及活性氧代谢的关系。以新疆‘西州蜜25号’甜瓜为试验材料，将60 μL/L的一氧化氮（nitric oxide，NO）气体充入密封箱熏蒸3 h，密封箱中不充入NO气体密封3 h的处理作为对照，放置12 h后损伤接种胶孢链格孢（Alternaria alternata），置于常温条件下贮藏。定期测定甜瓜果实病斑直径和病斑深度及与活性氧代谢相关的过氧化氢酶（catalase，CAT）、过氧化物酶（peroxidase，POD）、超氧化物歧化酶（superoxide dismutase，SOD）及超氧阴离子（superoxide anion，O2-?）的产生速率和过氧化氢（hydrogen peroxide，H2O2）的含量。结果表明：NO处理能明显降低贮藏期间甜瓜果实的病斑直径和病斑深度，诱导贮藏前期O2-?的产生速率加快和H2O2含量的快速积累，明显提高贮藏期间甜瓜果实SOD、CAT和POD的活性。说明NO处理诱导果实采后抗病性与调节果实的活性氧代谢密切相关。

Abstract:

The effects of fumigation treatment with nitric oxide on disease control and potentiation of metabolism of reactive oxygen species in post-harvest muskmelons were investigated. Xinjiang “Xizhoumi No. 25” muskmelons were fumigated with 60 μL/L of nitric oxide (NO) for 3 h in sealed boxes; melons kept in boxes without NO gas and sealed for 3 h were used as controls. After a 12 h treatment, the samples were inoculated with Alternaria alternata and stored at room temperature. The lesion diameter, lesion depth, rate of production of superoxide anion free radicals (O2-?), hydrogen peroxide (H2O2) content, and the activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) of the muskmelons were measured at regular intervals during storage. The results showed that the NO treatment significantly decreased the lesion diameter and lesion depth of muskmelons inoculated with A. alternata during the storage at room temperature. The NO treatment also induced the rapid accumulation of H2O2, and increased the rate of production of O2-? early in the storage. Furthermore, the NO treatment significantly enhanced SOD, CAT, and POD activities. This suggests that the disease resistance induced by NO treatment in post-harvest fruits is closely related to the regulation of the metabolism of reactive oxygen species.