渗氧对水稻砷吸收的影响及调控研究

项目名称： 渗氧对水稻砷吸收的影响及调控研究

项目编号： No.41201493

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 地理学

项目作者： 吴川

作者单位： 中南大学

项目金额： 25万元

中文摘要： 水稻是我国第一大粮食作物，砷污染严重影响稻米的产量和品质，危及人体健康。稻米砷污染问题已成为我国比较突出且急需解决的重要环境问题之一。水稻的通气组织和渗氧是其适应稻田湿地环境的决定因素，水稻的渗氧能力跟水稻地上部分砷（尤其是谷粒）的吸收以及谷粒无机砷含量成反比，调控环境因素可影响水稻的渗氧能力。本项目的研究基于对土壤水分条件和土壤硅含量等水稻砷吸收影响因素的探讨，分析土壤水分条件和硅对根的渗氧量（率）和孔隙度的影响及其作用机制，及其与砷在水稻的根际行为和砷在水稻体内形态和迁移转化之间的关系，找出提高水稻渗氧量（率）的方法，进而通过提高水稻的渗氧能力来减少水稻砷的吸收和积累，为砷低积累、高耐性的水稻品种在中低污染土壤的田间种植，减少可食谷粒中砷含量，降低水稻砷污染造成的健康风险提供理论依据。

中文关键词： 水稻；砷；硅；渗氧；铁膜

英文摘要： Arsenic (As) contamination is currently an environmental problem that has been receiving increasing concern. Substantial As contamination of paddy soil has now been found in China, and has adversely affected the health of millions of people that relies on rice as a staple food source. Therefore, there is an urgency to understand the mechanism of As tolerance and uptake by rice. The results of present proposal may be very valuable in revealing and explaining the physiological mechanisms of As uptake by rice, and can potentially provide valuable information in screening and breeding rice with low concentrations of As in their grains. Wetland plants including rice have adapted to waterlogged conditions by developing extensive aerenchyma in their roots. Rice roots constitutively form aerenchyma, and the amount is enhanced by waterlogging or oxygen-deficient conditions; porosity (gas volume/tissue volume) in plant tissues results from the intercellular gas-filled space formed as a constitutive part of development, which is enhanced by the formation of aerenchyma. In roots, oxygen is obviously required for respiration to provide sufficient energy for growth, maintenance, and nutrient uptake processes, and up to 30-40% of the oxygen supplied via the root aerenchyma is being lost to the soil, a process called radial oxy

英文关键词： rice；arsenic；silicon；radial oxygen loss；iron plaque