Systems-level analysis of the metabolic responses of the diatom Phaeodactylum tricornutum to phosphorus stress.
Phosphorus is an important macronutrient. To understand the molecular and cellular responses to phosphorus stress better, transcriptome profiling in combination with biochemical investigations was conducted in the model diatom Phaeodactylum tricornutum. Out of 10 402 predicted genes, 2491 and 405 genes were significantly upregulated or downregulated respectively. Unsurprisingly, genes associated with phosphate uptake were upregulated, such as the phosphate transporters and alkaline phosphatases. Genes encoding stress-shock proteins were accordingly upregulated, including genes associated with stress-responsive proteins, signal transduction and secondary metabolism. Additionally, genes related to protein translation, carbon fixation, glycolysis and the citric acid cycle were also upregulated. Genes associated with gene transcription were downregulated, thereby resulting in the upregulation of translation to compensate for the limited supply of messenger RNA. The downregulation of genes related to β-oxidation could contribute to the accumulation of fatty acids. Accordingly, triacylglycerols, which are important for energy storage, were determined to increase by 1.65-fold. Intracellular membranes, other than chloroplast membranes, tended to be dispersed; this finding was in accordance with the increased transcription of a total of 11 genes encoding putative phospholipases. Taken together, this work revealed the coordination of multiple metabolic pathways and certain key genes in the adaptation of P. tricornutum to phosphorus stress.
Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institute, College of Life Science, Jinan University, Guangzhou, China.
Zhi-Kai
ZK
Yang
Jian-Wei
JW
Zheng
Ying-Fang
YF
Niu
Wei-Dong
WD
Yang
Jie-Sheng
JS
Liu
Hong-Ye
HY
Li
D000222:Adaptation, Physiological; D057486:Carbon Cycle; D002952:Citric Acid Cycle; D017377:Diatoms / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling; D006019:Glycolysis; D007425:Intracellular Membranes / Q000378:metabolism; D050356:Lipid Metabolism; D028061:Phosphate Transport Proteins / Q000235:genetics / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017423:Sequence Analysis, RNA; D013312:Stress, Physiological; D059467:Transcriptome; D015854:Up-Regulation
D028061:Phosphate Transport Proteins; D012333:RNA, Messenger; D010758:Phosphorus