早衰基因ES1影响水稻失水

发布时间：2018-05-25 18:40

本文选题：ES1 + 失水　；参考：《中国农业科学院》2016年博士后论文

【摘要】：干旱是一个世界性的问题,已成为21世纪威胁农业生产、限制农业可持续性发展战略的全球焦点问题。水分散失过快通常会使植物受到干旱胁迫,引起植物的早衰。本研究中,我们分离到了一个水稻早衰突变体early senescence 1(es1), esl苗期叶片边缘就开始发白、枯萎,表现出失水状态,到了三叶期就出现早衰现象。本研究对该突变体进行了等位性检测、叶片细胞形态学切片观察,突变性状遗传分析,早衰控制基因的图位克隆及功能初步研究,主要结果如下：1)获得稳定遗传的早衰突变体esl,遗传分析表明,该突变性状是单隐性核基因控制的质量性状。2)利用图位克隆法克隆出控制水稻早衰基因ES1,早衰突变体esl发生单碱基突变,突变事件发生在剪接位点上,由于剪接错误导致读码框移位,提前终止,造成基因功能的改变。通过互补验证,确定早衰突变表型由此基因突变造成。借助图位克隆手段克隆了ESl基因,ESl基因编码一个SCAR-like protein2,该蛋白与actin polymerization相关,是SCAR/WAVE complex的一部分。3)ESl基因突变以后,esl单位叶面积上的气孔数明显增多,而且大多处于半张半闭状态,从而导致水分散失过快,加快了esl的水分循环,从而引起esl根部吸水能力增强,茎秆的水分运输能力也增强了,同时伴随水分一起运输的金属离子在体内富集。4)表达量检测表明ES1在叶片和叶鞘中的表达量要高于其它组织,这与其影响水稻失水的功能是吻合的。将ES1融合GFP报告基因,发现该基因在细胞质中进行表达。总之,我们研究结果表明ES1基因影响水稻的失水。
[Abstract]:Drought is a worldwide problem, which has become the global focus of the strategy of threatening agricultural production and restricting the sustainable development of agriculture in the 21st century. Excessive water loss usually causes plants to suffer drought stress, causing premature senescence. In this study, we isolated a rice early senescence mutant, early senescence 1, which began to grow white and withered at the leaf edge of esl at seedling stage, showing water loss, and premature senescence at the trefoil stage. In this study, the alleles of the mutant were detected, the morphological sections of leaf cells were observed, the genetic analysis of mutant traits, the mapping and cloning of premature senescence control gene and the function of the mutant were preliminarily studied. The main results were as follows: (1) the stable genetic mutant ESL was obtained. Genetic analysis showed that, The mutant trait is the quality trait controlled by single recessive nuclear gene. 2) the rice premature senescence gene ES1 was cloned by map cloning method. The single base mutation occurred in esl, and the mutation event occurred at the splicing site. Due to splicing error, reading frame shift, early termination, resulting in changes in gene function. By complementary verification, the phenotype of premature senescence mutation was determined to be caused by gene mutation. A SCAR-like protein 2 gene encoding ESl gene was cloned by means of map-based cloning. The protein was associated with actin polymerization. It was a part of SCAR/WAVE complex. The stomatal number per leaf area increased obviously after the SCAR/WAVE complex gene mutation, and most of them were in a semi-open and semi-closed state. As a result, the water loss is too fast, and the water cycle of esl is accelerated, which leads to the increase of the water absorption capacity of the esl root and the water transport capacity of the stem. The results showed that the expression of ES1 in leaves and sheaths was higher than that in other tissues, which was consistent with its function of affecting rice water loss. ES1 fusion GFP reporter gene was found to be expressed in the cytoplasm. In conclusion, our results suggest that the ES1 gene affects water loss in rice.
【学位授予单位】：中国农业科学院
【学位级别】：博士后
【学位授予年份】：2016
【分类号】：S511

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