铁是植物生长必需的矿质元素，在中性和石灰性土壤中铁的有效性显著降低。土壤铁的有效性与水稻产量和籽粒品质密切相关。植物激素赤霉素和油菜素内酯在调控水稻生长发育、形态建成和产量方面发挥着重要的作用。近些年有研究暗示二者也可能参与了植物的矿质养分吸收和利用过程。我们前期的研究结果证明这两种激素参与了水稻铁营养过程，但其机理尚不清楚。因此，在我们前期的工作基础上，本项目将充分利用赤霉素和油菜素内酯合成代谢、信号传递相关的水稻突变体材料，系统研究赤霉素和油菜素内酯在水稻铁吸收、运输和铁向籽粒转移过程中单独的和相互的作用；揭示二者在水稻不同生育期铁吸收、运输和铁向籽粒转移过程中的生物学机制；解析赤霉素和油菜素内酯在水稻缺铁信号传递过程中的调控关系。研究成果有助于发现赤霉素和油菜素内酯的新功能，丰富植物铁营养调控机制，为提高水稻铁的利用效率和籽粒品质提供新途径。

Iron (Fe) is one of the essential nutrients required for plant growth and development. Plant growth is often limited by low availability of Fe in soil due to its low solubility, especially in calcareous soils. Iron deficiency is a main factor limiting rice production and rice grain quality. Gibberellin (GA) and brassinosteroid (BR) are important plant hormones involved in a wide range of biological processes, including plant growth, development, environmental response and production, but little information is available about their effects on Fe acquisition, translocation and allocation in rice. In this project, wild type (WT), mutants related to GA and BR biosynthesis and signal transduction are used to investigate the roles of GA and BR in Fe uptake, translocation and allocation, and to dissect the network associated with their signal transduction pathways in response to Fe status. The outcome will contribute to mechanistic understanding the function of GA and BR in plant Fe nutrition, and further application of the GA and BR knowledge in rice to improve Fe use efficiency, production and grain quality.