浅水湖泊草源型活性氧物种（ROS）的生消特征与机制

Reactive oxygen species (ROS) are strong oxidizing substances that are involved in the photochemical reaction as well as the oxidation-reduction reaction in water body. ROS are the important factor that affect the migration, transformation, fate and the ecological effect of organic matters in water environment. The aquatic plant is a key component of the ecological system of lakes. Study of the ROS production from aquatic plants will help to discover the environmental behaviors of the ROS and also facilitates the understanding of the purification ability of aquatic plants on water pollutants. However, the characteristics and mechanisms of ROS production from aquatic macrophyte plants in shallow lakes are still not well understood. This proposal will use the aquatic plants in grass-type zones in Taihu Lake as a model and through indoor-simulation and field-observation to study the ROS produced during plant development and after plant death. The main contents in the project include the temporal and special characteristics of the ROS production and the correlation with environmental factors through; the determination of main factors influencing ROS production from aquatic plants; and the application of metagenomics technology to analyze the interactions between light and microorganisms; as well as to determine the stability of ROS in aquatic environment. Based on the studies mentioned above, this project will obtain the characteristics and mechanisms of the production of ROS by aquatic plants in shallow lakes. This project is extremely valuable for managing the lake environment and will provide important theoretical support for the ecological restoration function of aquatic plants.

活性氧物种（ROS）是一类具有强氧化性的物质，参与水体的光化学、氧化还原反应，是影响有机污染物在水环境中的迁移、转化、归宿及生态效应的重要因素。水生植物是湖泊生态系统的重要组成部分，研究水生植物对水环境中贡献的ROS既有利于了解水体中ROS的环境行为，也有利于提高水生植物对水体污染物净化能力的认识。然而目前对于草源型ROS的生消特征及机制并不清楚。本项目以太湖草型区水生植物为研究对象，通过室内模拟及野外验证实验，首先研究草型湖区ROS时空变化特征及其与环境因子的关联性；进而分析草源型ROS产生过程中的关键影响因素；再应用宏基因组技术研究草源型ROS产生过程中光和微生物相互作用关系；最后确定草源型ROS的环境稳定性，以最终揭示浅水湖泊水生植物生长期与衰亡期ROS的生消特征及机制。本项目在湖泊环境治理方面有重要的应用价值，同时为湖泊中水生植物的生态修复功能提供重要的理论支持。

活性氧物种（ROS）是影响有机污染物在水环境中的迁移、转化、归宿及生态效应的重要因素。水生植物是湖泊生态系统的重要组成部分，研究水生植物对水环境中贡献的ROS既有利于了解水体中ROS的环境行为，也有利于提高水生植物对水体污染物净化能力的认识。然而目前对于草源型ROS的生消特征及机制并不清楚。本项探究了浅水湖泊水体中光和微生物对植物残体的协同降解作用，构建了浅水湖泊水体中植物残体分解的光-微生物联合驱动机制；进一步研究发现光降解和微生物降解对植物残体的短期和长期分解阶段产生的可溶性有机物（DOM）的组分也有着不同的影响，并且在这一过程中，ROS的产生同样发挥着促进其中难降解组分的去除的作用；不同湖泊中（鄱阳湖、太湖）ROS产生特征分析以及主要影响因素，如ROS在鄱阳湖的丰水期的产率均显著高于枯水期，丰水期的DOM以外源为主，具有较高的分子量、芳香性和腐殖化程度，一些难降解组分，如木质素类和富含羧基的脂环分子(CRAM)是引发丰水期较高ROS产生的关键组分，而丰水期较高ROS稳态浓度显著缩短了水体中乙草胺降解的半衰期；提供了一种预测ROS产生的新方法，对水位变化下ROS介导下污染物的动态变化具有重要的指导意义；最后，研发了一种实时原位同步获取水体、沉积物或土壤中活性氧物种含量的装置及方法。本项目在湖泊环境治理方面有重要的应用价值，同时为浅水湖泊中水生植物的生态修复功能提供重要的理论支持。