title: Phosphorus supply drives rapid turnover of membrane phospholipids in the diatom Thalassiosira pseudonana.
abstract: 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.
authors.affiliation: Ocean Biogeochemistry and Ecosystems, National Oceanography Centre, Southampton, UK. patrick.martin@noc.soton.ac.uk
authors.forename: Patrick
authors.initials: P
authors.lastname: Martin
authors.forename: Benjamin A S
authors.initials: BA
authors.lastname: Van Mooy
authors.forename: Abigail
authors.initials: A
authors.lastname: Heithoff
authors.forename: Sonya T
authors.initials: ST
authors.lastname: Dyhrman
mesh_terms: D017377:Diatoms / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D008563:Membrane Lipids / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism*; D010839:Phytoplankton / Q000166:cytology / Q000378:metabolism
chemical_list: D008563:Membrane Lipids; D010743:Phospholipids; D010758:Phosphorus