TY - JOUR
T1 - The pigment composition of Phaeocystis antarctica (Haptophyceae) under varius conditions of light, temperature, salinity, and iron
AU - van Leeuwe, Maria A.
AU - Visser, Ronald J. W.
AU - Stefels, Jacqueline
PY - 2014/12
Y1 - 2014/12
N2 - 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.
AB - 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.
KW - 19 '-Hexanoyloxyfucoxanthin
KW - CHEMTAX
KW - fucoxanthin
KW - HPLC
KW - irradiance
KW - Phaeocystis
KW - pigments
KW - salinity
KW - temperature
KW - PHYTOPLANKTON COMMUNITY STRUCTURE
KW - SOUTHERN-OCEAN
KW - SEA-ICE
KW - PRYMNESIOPHYTE PHAEOCYSTIS
KW - PHOTOSYNTHETIC RESPONSES
KW - FRAGILARIOPSIS-CYLINDRUS
KW - CHEMTAX ANALYSIS
KW - ALGAE
KW - CHEMOTAXONOMY
U2 - 10.1111/jpy.12238
DO - 10.1111/jpy.12238
M3 - Article
VL - 50
SP - 1070
EP - 1080
JO - Journal of Phycology
JF - Journal of Phycology
SN - 0022-3646
IS - 6
ER -