根表铁膜是水稻适应水生环境的重要物理屏障和养分库。稻田干湿交替过程是水稻生长过程中常见的管理方法，研究稻田干湿交替驱动水稻根表铁膜的形成机理，对阻止有害重金属和有机污染物通过水稻根系进入籽粒具有重要意义。本项目拟利用铁膜数量差异显著的水稻品种为材料，利用DCB方法、电镜、X射线与能谱分析仪等表征水稻根表铁膜的种类、数量与分布；利用微电极、色谱与质谱联用仪等测定水稻根际Eh值和氧化性物质的动态变化，明确干湿交替驱动根表铁膜形成的根际特征。然后，借助组织化学染色和比色法等测定水稻根系抗氧化酶活性、活性氧累积等，明确干湿交替驱动根表铁膜形成的生理机制。在此基础上，利用高通量测序和Pathway显著性富集分析，分离干湿交替诱导铁膜形成的差异表达基因；借助农杆菌介导转化，获得转基因材料；并评价转基因材料在铁膜形成过程中的作用。该研究结果对阐明水稻根表铁膜的形成机制和水稻新品种选育具有重要科学意义

Iron plaque on root surface is an important physical barrier and nutrient pool. Soil drying and wetting alternation is a traditional management strategy in rice production. Studying the formation mechanism of iron plaque can provide scientific basis for improvement of rice quality and production. In this study rice varieties differing in iron plaque quantity will be used as experimental materials. Equipment and methods including DCB method, electron microscope, X-ray photoelectron spectrometry etc. will be used to characterize the type, quantity and distribution of iron plaque. Microelectrode and chromatograph mass spectrometer will be used to measure rhizospheric Eh value and dynamics of oxidative substances. The above results will contribute to elucidating rhizospheric characteristics driven by wetting and drying alteration. Then histochemical staining and colorimetric method will be used to determine the activities of antioxidant enzymes, reactive oxygen species etc. so as to understand the physiological mechanism of iron plaque formation driven by drying and wetting alteration. Based on the above results, high throughput sequencing technique and pathway analysis will be used to isolate differential expressed genes. Transgenic plants will be made by using agrobacterium tumefaciens mediated transformation. The function of a candidate gene in forming iron plaque will be evaluated during wetting and drying alteration. Thus the molecular mechanism of iron plaque formation will be explored. The above results will play an important role in elucidating formation of iron plaque and provide scientific evidences for breeding new rice varieties.