氮限制有利于三角褐指藻脂质积累  

Changes in central carbon metabolism of Phaeodactylum tricornutum are beneficial for lipid accumulation under nitrogen starvation conditions

作　　者：赵佩佩[1,2] 顾文辉[1] 伍松翠 解修俊[1] 赵宇鹏[3] 黄爱优[1] 郇丽[1,2] 潘光华[3] 王广策[1] 

机构地区：[1]中国科学院海洋研究所,青岛266071 [2]中国科学院大学地球科学学院,北京100049 [3]天津科技大学海洋科学与工程学院,天津300457

出　　处：《科学通报》2015年第23期2196-2208,共13页Chinese Science Bulletin

基　　金：科技部国家科技基础性工作专项(2012FY112900-01);科技部国际合作专项(2015DFG32160);中国科学院先导专项项目(XDA11020404;XDA05030401);天津市自然科学基金重点项目(12JCZDJC22200)资助

摘　　要：三角褐指藻是一种重要的海洋硅藻,其全基因组已完成测序.三角褐指藻富含脂肪酸,是一种潜在的生物柴油原料.因此,三角褐指藻是一种极具应用前景的模式海藻.本文分别在蛋白质组、转录组和生理水平上比较分析三角褐指藻在正常培养和缺氮培养下的变化.研究结果表明,细胞骨架、染色体组分及参与信号转导的多个蛋白的含量在缺氮条件下变化明显,蛋白质降解加速以利于氨基酸的重新利用;涉及光合作用和卡尔文循环的多个酶显著下调,叶绿素生物合成相关蛋白含量降低,光合效率明显下降;糖酵解和三羧酸循环相关蛋白的转录和表达水平大幅上调,脂肪酸合成过程中多个关键酶也表现为上调趋势.同时,尼罗红(Nile red)和氟硼荧(BODIPY)染色实验结果显示,三角褐指藻细胞在缺氮条件下脂滴增大.基于以上结果,本文认为,氮限制促进了三角褐指藻中脂质的积累,糖酵解和三羧酸循环的强化为脂质合成提供了充足的底物和能量.Phaeodactylum tricornutum is an important diatom that is rich in fatty acids. Information on its whole genome is publicly available. Here, we studied the proteome, transcriptome, and physiology of this organism in normal culture and under nitrogen starvation conditions. Our results showed that protein metabolism, the cytoskeleton, chromatin, and other bioprocesses including signal transduction changed dramatically when nitrogen was unavailable. Under the nitrogen starvation condition, photosynthesis and the Calvin cycle were down-regulated, while glycolysis, the TCA cycle, and lipid biosynthesis were up-regulated compared with the normal culture control. We suggest that the up-regulated glycolysis and TCA cycle may provide large amounts of substrates and energy for lipid biosynthesis. Nile red and BODIPY staining of P. tricornutum revealed that the lipid bodies were enlarged in the nitrogen-starved cells compared with the controls. These findings indicate that limited availability of nitrogen can stimulate the accumulation of lipids in P. tricornutum.

关 键 词：硅藻 脂质合成 代谢路径 蛋白质组学 三角褐指藻 

分 类 号：Q946[生物学—植物学]