Phosphorus supply drives rapid turnover of membrane phospholipids in the diatom Thalassiosira pseudonana

• Published in: The ISME Journal Vol. 5; no. 6; pp. 1057 - 1060
• Main Authors: Martin, Patrick, Van Mooy, Benjamin AS, Heithoff, Abigail, Dyhrman, Sonya T
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.06.2011; Oxford University Press; Nature Publishing Group
• Subjects: 631/158/2446/2447; 631/326/47; 631/45/287/1194; Biomedical and Life Sciences; Diatoms - chemistry; Diatoms - cytology; Diatoms - metabolism; Ecology; Evolutionary Biology; Life Sciences; Lipids; Marine systems; Membrane Lipids - metabolism; Membranes; Microbial Ecology; Microbial Genetics and Genomics; Microbiology; Phospholipids - metabolism; Phosphorus; Phosphorus - metabolism; Physiology; Phytoplankton; Phytoplankton - cytology; Phytoplankton - metabolism; Reservoirs; Short Communication; Thalassiosira pseudonana; non-phosphorus lipids; betaine lipids; diatoms; DGCC; lipid substitution; phosphatidylcholine
• DOI: 10.1038/ismej.2010.192
• ISSN: 1751-7362; 1751-7370

In low-phosphorus (P) marine systems, phytoplankton replace membrane phospholipids with non-phosphorus lipids, but it is not known how rapidly this substitution occurs. Here, when cells of the model diatom Thalassiosira pseudonana were transferred from P-replete medium to P-free medium, the phospholipid content of the cells rapidly declined within 48 h from 45±0.9 to 21±4.5% of the total membrane lipids; the difference was made up by non-phosphorus lipids. Conversely, when P-limited T. pseudonana were resupplied with P, cells reduced the percentage of their total membrane lipids contributed by a non-phosphorus lipid from 43±1.5 to 7.3±0.9% within 24 h, whereas the contribution by phospholipids rose from 2.2±0.1 to 44±3%. This dynamic phospholipid reservoir contained sufficient P to synthesize multiple haploid genomes, suggesting that phospholipid turnover could be an important P source for cells. Field observations of phytoplankton lipid content may thus reflect short-term changes in P supply and cellular physiology, rather than simply long-term adjustment to the environment.