OsDTRF1基因调控陆稻陆生适应性的分子和生理机制研究

栽培稻长期进化分别形成了适应水生和陆生的生态种，水稻和陆稻。项目前期利用群体遗传学、比较和进化基因组学鉴定到陆稻生态型分化基因OsDTRF1，该基因响应ABA信号和干旱胁迫差异表达，过表达OsDTRF1可以提高水稻抗旱性，增强植株的旱地适应能力，并鉴定到2个与OsDTRF1互作的bHLH转录因子蛋白OsIRO2和OsIRO3，暗示OsDTRF1通过调控铁离子的吸收和转运介导陆稻的陆生适应性，但OsDTRF1如何发挥陆生适应性调控功能的分子和生理机制尚不清楚。本项目拟在已有工作基础上，明确OsDTRF1介导铁离子吸收/转运和陆生适应性的调控功能；解析OsDTRF1与OsIRO2、OsIRO3互作调控的下游通路等分子机制，揭示铁离子参与植株陆生适应性调控的生理机制，最终阐明OsDTRF1介导陆稻陆生适应性进化的作用机制。研究成果将为水稻耐旱种质资源创新和新品种培育提供新的基因资源和功能标记。

Cultivated rice has evolved for long time to form both aquatic and terrestrial ecological species, irrigated rice and upland rice, respectively. To better facilitate drought-resistance breeding in rice, it is of great importance to identify drought tolerant germplasms and genes. In our previous study, an upland rice ecotypic differentiation gene OsDTRF1 was identified using population genetics, comparative and evolutionary genomics approaches. Results indicated that OsDTRF1 was significantly differential expressed in response to ABA signal and drought stress, and overexpressing OsDTRF1 could improve the drought resistance and aerobic adaptation in rice. Two bHLH transcription factor proteins, OsIRO2 and OsIRO3, were preliminarily screened and verified to interact with OsDTRF1, suggesting that OsDTRF1 might also play a role in Fe2+ absorption and transport. However, the molecular and physiological mechanisms of OsDTRF1 in drought resistance and its roles in population differentiation between the irrigated and upland rice remained unclear. Based on our previous studies, the aims of this project are further to verify the biological function of OsDTRF1 in regulating drought resistance and aerobic adaptation, to study different heterodimers formed by OsDTRF1, OsIRO2 and/or OsIRO3, and their downstream regulatory pathways. Furthermore, the physiological mechanism of Fe2+ participating in drought resistance and aerobic adaptation of plants will be clarified. The results of this study would provide theoretical basis for better understanding the molecular foundation and mechanisms of OsDTRF1 in regulating the adaptability of upland rice to aerobic environment, and offer new genes and markers for rice drought-resistance breeding.