根际功能糖耦合电子载体抑制高氯酸盐植物吸收的化学机理

Perchlorates in environments are a new and noticeable persistent pollutant recently. Perchlorate-containing soils have become an increasingly serious problem in China. Accumulation of perchlorate in plant could poses a threat to quality security of agricultural products. The potential cumulative risk of perchlorates may be reduced by a saccharide-relevant chemical process in exudates of rhizosphere, in which perchlorates are attenuated by a reduction process of functional saccharides coupled with electron shuttles. However, few information can be found so far. The main goal of this study is to elucidate the major mechanism regarding the restrained plant uptake of perchlorate by function saccharides coupled with electron shuttles in rhizosphere. The aims are: (1) to investigate the rhizosphere processes which affect the reduction of perchlorate, on the basis of fluorescent micro titration technology and micro-/meso-cosm systems; (2) to quantify the contribution of key chemical process of saccharides to attenuation of perchlorate, based on the analyses of reactive kinetics, isotope labelling, and computational chemistry; (3) to characterize the association of plant uptake of perchlorate with the attenuation in rhizosphere; (4) expound the chemical mechanisms regarding function saccharides coupled with electron shuttles in rhizosphere during the perchlorate reduction. It is expected that the information obtained from the study may provide a support for explaining the principle of perchlorate pollution in rhizosphere, reducing pollution risk of agricultural products, improving quality security of agricultural products.

高氯酸盐是近年来很受关注的一类新型持久性污染物。我国土壤高氯酸盐污染范围广、形势严峻；植物吸收高氯酸盐造成农产品安全问题。利用植物根际分泌的大量糖还原高氯酸盐污染物、减小植物对高氯酸盐的吸收，进而可有效规避植物高氯酸盐污染风险；但难以检索到相关资料。本项目拟以我国污染土壤中常见的高氯酸盐为目标污染物，拟采用计算化学、谱学分析、微/中宇宙与土培等实验方法，在弄清植物根系、体内功能糖对高氯酸盐还原的基础上，研究影响高氯酸盐转变的根际过程、确定关键糖化学过程对高氯酸盐根际衰减的贡献、揭示根际过程影响高氯酸盐植物吸收的内在规律、阐明根际关键糖耦合电子载体化学还原高氯酸盐的机制。预期将促进荧光微滴定、同位素示踪、计算化学等新方法在污染物糖化学转化过程研究方面的应用。成果可为深入揭示高氯酸盐根际污染规律、减低作物污染风险、保障农产品安全等提供重要思路和依据。

高氯酸盐是近年来很受关注的一类环境新型持久性污染物。我国土壤高氯酸盐污染范围广、形势严峻，植物吸收高氯酸盐造成农产品安全问题。根际是植物和微生物活动的重要区间，其分泌的大量的有机分子可通过物理和化学途径作用于高氯酸盐污染物、减小植物对高氯酸盐的吸收，进而可有效规避可食用农产品的高氯酸盐吸收风险；但相关报道较少。本项目以我国污染土壤中常见的高氯酸盐为目标污染物，拟采用计算化学、谱学分析、微/中宇宙试验等方法，在弄清植物根系、体内功能组分对高氯酸盐物化学转化的基础上，研究影响高氯酸盐转变的根际过程、阐明关键根际化学过程对高氯酸盐根际衰减的贡献、揭示根际过程与高氯酸盐植物吸收的内在联系、找出根际关键糖耦合电子载体化学还原高氯酸盐的机制。成果将促进荧光微滴定、计算化学、现场分析等新方法在污染物环境过程研究方面的应用。成果可为深入揭示高氯酸盐根际污染规律、减低作物污染风险、保障农产品安全等提供重要思路和依据。在国际刊物出版学术论文5篇，含Environ. Sci. Technol.两篇；培养研究生3名；参加国际和国内会议共3人次。