Soft rot caused by is one of the most serious postharvest bacterial diseases of green peppers. The present research aimed to determine the biocontrol effect of on postharvest soft rot of green peppers and to further delve into biocontrol mechanisms by analyzing the metabolism of reactive oxygen species (ROS) in green peppers. As key results, soft rot occurrence of green peppers was alleviated with the increase of the concentration of , and the disease incidence and index of the fruits treated with 1 × 10 CFU/mL of for 4 d were 28.3% and 12.7%, respectively, which were significantly decreased compared with that of the control. could significantly increase NADPH oxidase (NOX) activity in green peppers to trigger ROS outbreaks, which induced defense response of the fruits. Furthermore, it promoted the enzymatic activities of the ROS scavenging system, including antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT)), ascorbic acid-glutathione (AsA-GSH) cycle-related enzymes (ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione reductase (GR)), glutathione peroxidase (GPX) cycle-related enzymes (GPX, GR and glutathione--transferase (GST)). Besides, increased the non-enzymatic ROS scavenging system contents, including ascorbate (AsA) and glutathione (GSH) in green peppers. Importantly, the levels of O·, HO and malondialdehyde (MDA) in green peppers were reduced, thereby enhancing green pepper disease resistance. This study offers novel insights to advanced strategies in preventing and controlling postharvest soft rot in green peppers.

中文翻译：

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枯草芽孢杆菌调控ROS代谢控制青椒采后软腐病

软腐病是青椒采后最严重的细菌性病害之一。本研究旨在通过分析青椒活性氧（ROS）的代谢情况，确定其对青椒采后软腐病的生防效果，并进一步深入探讨生防机制。主要结果是，青椒软腐病的发生随着浓度的增加而减轻，1×10 CFU/mL处理4 d的果实发病率和指数分别为28.3%和12.7%。与对照相比显着降低。可以显着增加青椒中 NADPH 氧化酶（NOX）的活性，引发 ROS 爆发，从而诱导果实的防御反应。此外，它还促进ROS清除系统的酶活性，包括抗氧化酶（超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT））、抗坏血酸-谷胱甘肽（AsA-GSH）循环相关酶（抗坏血酸）过氧化物酶（APX）、单脱氢抗坏血酸还原酶（MDHAR）、脱氢抗坏血酸还原酶（DHAR）、谷胱甘肽还原酶（GR））、谷胱甘肽过氧化物酶（GPX）循环相关酶（GPX、GR和谷胱甘肽转移酶（GST））。此外，还增加了青椒中非酶ROS清除系统的含量，包括抗坏血酸（AsA）和谷胱甘肽（GSH）。重要的是，青椒中O·、H2O和丙二醛（MDA）的水平降低，从而增强了青椒的抗病性。这项研究为预防和控制青椒采后软腐病的先进策略提供了新的见解。