海带硝酸盐还原酶基因表达与酶活的调控机制

项目名称： 海带硝酸盐还原酶基因表达与酶活的调控机制

项目编号： No.41306179

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 天文学、地球科学

项目作者： 徐东

作者单位： 中国水产科学研究院黄海水产研究所

项目金额： 26万元

中文摘要： 氮素既是组成植物有机体最重要的元素之一，又是其生理代谢中生物催化剂的主要组分，其代谢对植物生命活动至关重要。硝酸盐还原酶NR是植物氮素同化的关键酶，催化体内的硝酸盐还原为亚硝酸盐，形成氨基酸和蛋白质后参与有机体构成。项目以海带为研究对象，获取其nr基因的全长序列，通过系统发生分析推测其在进化过程中的地位；分别测定不同处理条件下海带配子体、幼孢子体及成熟孢子体NO3-吸收效率、组织氮含量、nr基因表达水平和酶的催化活性，明确基因表达、酶催化活性与各生理指标的相关性，分析海带NR基因表达与催化活性对主要环境因子的响应及调控机制；检测nr基因在光周期下的昼夜表达模式，明确nr基因表达是否具有内源节律性。项目有助于揭示大型海洋褐藻氮素代谢途径的分子调控机制，为正确评估海洋藻类环境修复潜力以及揭示海洋生物的适应能力和调节机制提供理论基础。

中文关键词： 海带；硝酸盐还原酶；基因表达；酶活调控；

英文摘要： The nitrogen is not only the important substance in plant tissue structure, but also the most active and ubiquitous element as the main component of the enzyme in physiological metabolism, playing a significant role in nitrogen metabolism in plant life. An important way by which plants incorporate nitrogen to their metabolism is the assimilation of nitrate, which should reduce nitrate to nitrite, converted to ammonia and further incorporated into amino acids and protein. In this study we would firstly clone and characterize of the nitrate reductase gene in Saccharina japonica. Its roles and position would be revealed by phylogenetic analysis. Secondlly, the nitrate uptake rate, tissue nitrogen concentration, nitrate reductase activity and nr expression under different stress conditions would be determined respectively. The correlationship between gene expression, nitrate reductase activity, and relative physiological parameters will be defined. The respondence of nr expression and NR activity to primary environmental factors and their modulation mechanism will be analyzed. Finally, the daily rhythm of nr expression relative to different photoperiod was determined and analyzed to check whether it was endogenous controlled. This study will illustrate the molecular mechanism of nitrogen metabolism in marine brown m

英文关键词： Saccharina japonica；nitrate reductase；gene experession；enzyme activity regulation；