| 论文标题： | |
|---|---|
| 作者： | |
| 出版刊物： | |
| 出版日期： | |
| 出版年份： | |
| 卷/期： | |
| DOI： | |
| 论文摘要： | The tricarboxylic acid (TCA) cycle is a key metabolic pathway that unifies carbohydrate, lipid and protein metabolism. In Phaeodactylum tricornutum, accumulation of triacylglycerols (TAGs) under nitrogen stress is a consequence of re-allocation of carbon mainly from the intermediates of TCA cycle. Oxaloacetate, an intermediate of the TCA cycle, can flux out of the cycle by the decarboxylation enzyme phosphoenolpyruvate carboxykinase (PEPCK), thus decreasing the carbon flow directed to fatty acid biosynthesis. We assayed the expression of genes encoding mitochondrially-localized decarboxylation enzymes, essential for putative C-4 metabolism, in P. tricornutum. Targeted knockdown of PEPCK was performed using RNA-interference and the photosynthetic characteristics and TAG contents of knockdown lines were characterized. PEPCK was significantly upregulated at both the mRNA and protein levels during TAG accumulation in P. tricornutum, and both PEPCK transcript abundance and enzyme activity were reduced significantly in two RNAi lines. The mutants exhibited lower photosynthetic activity, while TAG content was markedly increased. Meanwhile, cell density was comparable with that of wild-type. We propose that carbon from decarboxylation of C4 metabolites in the mitochondria plays a minor role in carbon concentration in this diatom. Downregulated decarboxylation succeeded in increasing lipid accumulation by decreasing the loss of carbon skeletons without compromising cell biomass. (C) 2016 Elsevier B.V. All rights reserved. |
以下内容与「星空体育彩票官网正规渠道」同属公开资讯，可按栏目接着查阅相关条目。
本站按公开材料组织页面。需要原文时请核对应栏目发布页。
若从搜索引擎进入，可先确认当前栏目名称，再按需打开相关阅读。
