水稻线粒体RNA编辑与雄性不育的研究

RNA editing is a molecular process on RNA by changing specific nucleotide sequences, which can produce a novel protein or peptide. Studies showed RNA editing is widely distributed in plant mitochondria and chloroplast, which is essential for plant development, although the mechanism is unclear. In previous studies, we selected several PPR-DYW proteins as candidate gene for researches on RNA editing. Among them, a RNAi line exhibited male sterility and decreased seed setting, termed as pss2. Data suggested the RNA editing of nad3 is decreased in pss2, while other editing sites were not affected. In this project, we will take the strategies of BN-PAGE and protein activities tests to analyze the activities of five complexes of electron transport chain. We will also perform protein expression, EMSA and RNA editing activities tests to analyze the RNA binding and/or catalytic activities of PSS2. We will use yeast 2 hybrid library to screen and identify some candidate interact factors of PSS2. Through these studies, we try our best to illustrate the biological function of PSS2 and contribute to understand the mechanism and process of RNA editing in plant. It also provides reference for creating male sterile germplasm, and broaden the way of heterosis utilization in crops.

RNA编辑是指在RNA水平进行碱基改变的转录后调控，这种改变可产生新的蛋白或多肽。研究表明RNA编辑广泛存在于植物线粒体、叶绿体等细胞器中，在植物生长发育中发挥重要功能，但机理仍不清晰。在前期工作基础上通过对PPR基因家族分析，我们选择与RNA编辑密切联系的PPR-DYW基因展开研究，获得了一些重要进展。其中，突变体材料pss2表现出雄性不育，结实率降低，同时营养生长也有一定影响，研究表明pss2突变体中线粒体基因nad3的RNA编辑效率发生变化，而其他编辑位点没有差异。本项目拟通过BN-PAGE、蛋白酶活实验检测线粒体电子传递链各复合体活性，通过蛋白表达及蛋白-RNA互作验证PSS2的RNA结合活性，通过淘洗酵母文库获得PSS2互作的蛋白。通过阐明PSS2的生物学功能，进一步了解植物PPR-DYW基因参与RNA编辑的机理及过程，为创制雄性不育材料提供借鉴，拓宽农作物杂种优势利用的途径。

RNA编辑是指在RNA水平进行碱基改变的转录后调控，这种改变可产生新的蛋白或多肽，也可以提前终止原有的蛋白或多肽。研究表明RNA编辑现象在动物中较少，而在植物线粒体、叶绿体等细胞器广泛存在中，在植物生长发育中发挥重要功能，但机理仍不清晰。在前期工作基础上通过对PPR基因家族分析，我们选择多个与RNA编辑密切联系的PPR-DYW基因展开研究，获得了一些重要进展。在本项目的支持下，课题组克隆了PPS1、OsPGL1、PPR756等多个参与RNA编辑的PPR基因，研究了这些PPR基因的靶标RNA编辑情况以及水稻表型变异，同时分析了PPR蛋白与对应靶标RNA的体内、体外结合，以及PPR蛋白与MORFs之间的互作，为进一步了解植物PPR-DYW基因参与RNA编辑的机理及过程，以及创制雄性不育材料提供借鉴，拓宽农作物杂种优势利用的途径。