中文摘要：

人工湿地中植物发挥着至关重要的作用。植物根系能向基质中释放糖类、酸类等分泌物,从而影响根际微生物种类及分布等微环境特征,因此植物根系分泌物与根际微环境的关系逐渐受到关注。综述了近10年来植物根系分泌物组成与分泌机理等方面的研究进展,分析了温度、pH值、光照等环境因子及养分含量、微生物等对根系分泌物的影响,探讨了根系分泌物在养分胁迫的改善、金属毒性的改善、对根际微生物的影响及化感作用等方面对微环境的影响。在此基础上提出明确植物根系分泌内在机制及其与植物抗逆性的关系等研究方向。

英文摘要：

The present paper is aimed to provide a research review on advances in the relationship between the plant root exudates and the rhizosphere micro-environment in the constructed wetlands. A lot of studies prove that sewage can be treated in such wetlands, offering a low-cost, environment-friendly alternative for common eco-engineering systems. Since plant roots can release exadutes, such as saccharides and acids, they can have great effects on the ecological structure of the microbial population and the micro-environment around them. Therefore, more and more attention has been paid to the study of the relationship between the plant root exudates and the change of the rhizosphere micro-environment in recent years. In this paper, we would like to make a summary of the research advances over the plant root exudates and their interaction with their surroundings in recent decade. Thus, it can be seen that in this paper we have made a detailed commentary on the definition, composition and excretion mechanism of the plant root exudates, which serves as the leading substance reacting instinctively to the environment changes. And, then, we have made an analysis of the effects of the environmental factors （such as temperature, pH value, illumination, and CO2 concentration）. In addition, we have also analyzed the essential influence of the nutritious content containing both of rhizosphere and other microbes on the plant root exudates. On the other hand, the plant root exudates also react to the rhizosphere micro-environment and play its role in their constructed wetland ecological system. Since plants can relieve the stress of nutrients by releasing the root exudates, such as organic acids, acidic phosphatase and so on, they help to degrade some organic pollutants by secreted some enzymes. Some organic acids secreted by the plant roots can remove the metal toxicity, their root exudates of different plants can influence the soil microbial species, microflora and their physiological characteristics around the root. In addi