The pigment composition of Phaeocystis antarctica (Haptophyceae) under varius conditions of light, temperature, salinity, and iron

Maria A. van Leeuwe*, Ronald J. W. Visser, Jacqueline Stefels

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

25 Citations (Scopus)

Abstract

The pigment composition of Phaeocystis antarctica was monitored under various conditions of light, temperature, salinity, and iron. 19'-Hexanoyloxyfucoxanthin (Hex-fuco) always constituted the major light-harvesting pigment, with remarkably stable ratios of Hex-fuco-to-chl a under the various environmental conditions. Increased pigment-to-chl a ratios at low irradiance confirmed the light-harvesting function of Fucoxanthin (Fuco), 19'-Hexanoyloxy-4-ketofucoxanthin (Hex-kfuco), 19'-butanoyloxyfucoxanthin (But-fuco), and chl c2 and c3. Increased pigment-to-chl a ratios at high irradiance, low iron concentrations, and to a lesser extent at high salinity confirmed the photoprotective function of diadinoxanthin, diatoxanthin, and b,b-carotene. Pigment ratios were not always according to expectations. The consistent increase in But-fuco/chl at high temperature, high salinity, and low iron suggests a role in photoprotection rather than in light harvesting. Low Hex-kfuco/chl ratios at high salinity were consistent with a role as light harvester, but the high ratios at high temperature were not, leaving the function of Hex-kfuco enigmatic. Dedicated experiments were performed to test whether or not the light-harvesting pigment Fuco could be converted into its structural relative Hexfuco, and vice versa, in response to exposure to light shifts. Rapid conversions could not be confirmed, but long-term conversions cannot be excluded. New pigment ratios are proposed for chemotaxonomic applications. The ratios will improve pigment-based diagnosis of algal species in waters dominated by P. antarctica.

Original languageEnglish
Pages (from-to)1070-1080
Number of pages11
JournalJournal of Phycology
Volume50
Issue number6
DOIs
Publication statusPublished - Dec-2014

Keywords

  • 19 '-Hexanoyloxyfucoxanthin
  • CHEMTAX
  • fucoxanthin
  • HPLC
  • irradiance
  • Phaeocystis
  • pigments
  • salinity
  • temperature
  • PHYTOPLANKTON COMMUNITY STRUCTURE
  • SOUTHERN-OCEAN
  • SEA-ICE
  • PRYMNESIOPHYTE PHAEOCYSTIS
  • PHOTOSYNTHETIC RESPONSES
  • FRAGILARIOPSIS-CYLINDRUS
  • CHEMTAX ANALYSIS
  • ALGAE
  • CHEMOTAXONOMY

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