Gene Regulation of Carbon Fixation, Storage, and Utilization in the Diatom Phaeodactylum tricornutum Acclimated to Light/Dark Cycles
Gene Regulation of Carbon Fixation, Storage, and Utilization in the Diatom Phaeodactylum tricornutum Acclimated to Light/Dark Cycles
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DOI：
10.1104/pp.112.206177
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发表时间：
2013-02-01
期刊：
影响因子：
7.4
通讯作者：
Bones, Atle M.
中科院分区：
文献类型：
--
作者：
Chauton, Matilde Skogen;Winge, Per;Bones, Atle M.
本文报道了三角褐指藻在指数流加培养条件下，在细胞、代谢产物和基因表达水平上对碳代谢的调控。在所有时间点同时采样的转录谱和细胞化学提供了关于碳掺入、命运和调节的全面数据集。在整个光照期间观察到尼罗红荧光（细胞中性脂质的代表）增加，并且水溶性葡聚糖在光照期间迅速增加。在黑暗期间观察到葡聚糖和脂质的近线性下降，并且转录谱数据表明这种下降与有丝分裂的开始相关。超过4,500个转录本在光/暗周期中被差异调节，其中许多与碳水化合物和脂质代谢有关。以前没有在藻类中描述的基因及其对光的调节与代谢过程中的拟议作用一起整合在此分析中。一些非常快速的光响应基因，如脂肪酸生物合成被确定和分配到生物合成过程。转录本和细胞化学数据反映了光能可用性和消耗光能的代谢过程之间的联系。我们的数据证实了碳代谢过程的空间定位，无论是质体或线粒体或糖酵解/糖异生，这是本地化的细胞质，叶绿体和线粒体。定位和昼夜表达模式可能有助于确定不同同工酶的作用和挖掘参与光反应和昼夜节律的基因。
The regulation of carbon metabolism in the diatom Phaeodactylum tricornutum at the cell, metabolite, and gene expression levels in exponential fed-batch cultures is reported. Transcriptional profiles and cell chemistry sampled simultaneously at all time points provide a comprehensive data set on carbon incorporation, fate, and regulation. An increase in Nile Red fluorescence (a proxy for cellular neutral lipids) was observed throughout the light period, and water-soluble glucans increased rapidly in the light period. A near-linear decline in both glucans and lipids was observed during the dark period, and transcription profile data indicated that this decline was associated with the onset of mitosis. More than 4,500 transcripts that were differentially regulated during the light/dark cycle are identified, many of which were associated with carbohydrate and lipid metabolism. Genes not previously described in algae and their regulation in response to light were integrated in this analysis together with proposed roles in metabolic processes. Some very fast light-responding genes in, for example, fatty acid biosynthesis were identified and allocated to biosynthetic processes. Transcripts and cell chemistry data reflect the link between light energy availability and light energy-consuming metabolic processes. Our data confirm the spatial localization of processes in carbon metabolism to either plastids or mitochondria or to glycolysis/gluconeogenesis, which are localized to the cytosol, chloroplast, and mitochondria. Localization and diel expression pattern may be of help to determine the roles of different isoenzymes and the mining of genes involved in light responses and circadian rhythms.