果实采后品质保持的氧化还原生物学机制

果实采后衰老与品质劣变是由内在和外部因素引发的一种整体性退化过程，其中蛋白氧化损伤起主要作用。生物体内存在蛋白氧化还原调节器，如硫氧还蛋白（Trx）、谷氧还蛋白（Grx）、甲硫氨酸亚砜还原酶（Msr）等，它们直接或间接参与氧化蛋白修复和氧化还原信号途径，但目前相关认识主要源于哺乳动物和微生物的衰老或细胞凋亡。本项目以呼吸跃变型（如香蕉等）和非跃变型（如荔枝等）果实为材料，以采后果实在贮藏过程中蛋白氧化还原调节器Trx/Grx/Msr介导的蛋白氧化还原调控为核心，从蛋白质氧化特性、Trx/Grx/Msr对氧化胁迫的应答、Trx/Grx/Msr介导的代谢蛋白、抗氧化酶系统、转录因子的氧化修饰在采后果实成熟衰老和劣变的作用等方面，重点阐明采后果实品质保持的氧化还原调控的网络及作用机制。研究结果对于深入揭示采后果实衰老和品质劣变的机理及其调控机制具有重要意义，将为优化果实采后贮藏技术提供理论依据。

Harvest fruit senescence and quality deterioration is an overall degradation process caused by internal and external factor, in which protein oxidative damage plays a key role. Organisms possess protein redox regulators, such as thioredoxin (Trx), glutaredoxin (Grx), methionine sulfoxide reductase (Msr), which can directly or indirectly repair oxidized proteins and are involved in redox signaling pathways. However, related progresses are mainly made on mammals and microorganisms. This project is to investigate the roles of redox regulation of proteins by Trx, Grx and Msr in regulating harvested fruit senescence and quality deterioration. The following issues will be studied: (1) what are protein oxidation characteristics, including cysteine oxidation, methionine oxidation and glutathionylation, during harvested fruit senescence and quality deterioration ; (2) what are ROS-responsive transcription factors related to protein redox regulators (Trx, Grx and Msr) and how do these ROS-responsive transcription factors regulate the expression of protein redox regulators (Trx, Grx and Msr) ; (3) how do protein redox regulators (Trx, Grx and Msr) act on metabolic proteins related to ethylene synthesis, fruit softening and aromatic synthesis ; (4) how do protein redox regulators (Trx, Grx and Msr) act on antioxidant enzymes; (5) how do protein redox regulators (Trx, Grx and Msr) act on transcription factors related to fruit ripening and senescence. The results of the study will be of great significance to the illumination of the regulation mechanism of harvested fruit senescence and deterioration in terms of redox biology, which will provide theoretical knowledge for research and development of postharvest technologies.