title: Short- and long-term acclimation patterns of the giant kelp Macrocystis pyrifera (Laminariales, Phaeophyceae) along a depth gradient.
abstract: The giant kelp, Macrocystis pyrifera, is exposed to highly variable irradiance and temperature regimes across its geographic and vertical depth gradients. The objective of this study was to extend our understanding of algal acclimation strategies on different temporal scales to those varying abiotic conditions at various water depths. Different acclimation strategies to various water depths (0.2 and 4 m) between different sampling times (Jan/Feb and Aug/Sept 2012; long-term acclimation) and more rapid adjustments to different depths (0.2, 2 and 4 m; short-term acclimation) during 14 d of transplantation were found. Adjustments of variable Chl a fluorescence, pigment composition (Chl c, fucoxanthin), and the de-epoxidation state of the xanthophyll cycle pigments were responsible for the development of different physiological states with respect to various solar radiation and temperature climates. Interestingly, the results indicated that phlorotannins are important during long-term acclimation while antioxidants have a crucial role during short-term acclimation. Furthermore, the results suggested that modifications in total lipids and fatty acid compositions apparently also might play a role in depth acclimation. In Aug/Sept (austral winter), M. pyrifera responded to the transplantation from 4 m to 0.2 m depth with a rise in the degree of saturation and a switch from shorter- to longer-chain fatty acids. These changes seem to be essential for the readjustment of thylakoid membranes and might, thus, facilitate efficient photosynthesis under changing irradiances and temperatures. Further experiments are needed to disentangle the relative contribution of solar radiation, temperature and also other abiotic parameters in the observed physiological changes.
authors.affiliation: Marine Botany and Bremen Marine Ecology - Center for Research and Education (BreMarE), University of Bremen, Leobener Str. NW2, 28359, Bremen, Germany.
authors.forename: Kristina
authors.initials: K
authors.lastname: Koch
authors.affiliation: Facultad de Ciencias del Mar, Universidad Católica del Norte and Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Larrondo 1281, Coquimbo, Chile.|Nucleus Ecology and Sustainable Management of Oceanic Island (ESMOI), Coquimbo, Chile.
authors.forename: Martin
authors.initials: M
authors.lastname: Thiel
authors.affiliation: Marine Zoology and Bremen Marine Ecology - Center for Research and Education (BreMarE), University of Bremen, Leobener Str. NW2, Bremen, 28359, Germany.
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Hagen
authors.affiliation: Ecological Chemistry, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI), Am Handelshafen 12, Bremerhaven, 27570, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Graeve
authors.affiliation: Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Casilla 567, Valdivia, Chile.
authors.forename: Iván
authors.initials: I
authors.lastname: Gómez
authors.affiliation: Facultad de Ciencias del Mar, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile.
authors.forename: David
authors.initials: D
authors.lastname: Jofre
authors.affiliation: Marine Botany and Bremen Marine Ecology - Center for Research and Education (BreMarE), University of Bremen, Leobener Str. NW2, 28359, Bremen, Germany.|Max Planck Institute for Marine Microbiology, Celsiusstr. 1, Bremen, 28359, Germany.
authors.forename: Laurie C
authors.initials: LC
authors.lastname: Hofmann
authors.affiliation: Facultad de Ciencias del Mar, Universidad Católica del Norte and Centro de Investigación y Desarrollo Tecnológico en Algas (CIDTA), Larrondo 1281, Coquimbo, Chile.
authors.forename: Fadia
authors.initials: F
authors.lastname: Tala
authors.affiliation: Marine Botany and Bremen Marine Ecology - Center for Research and Education (BreMarE), University of Bremen, Leobener Str. NW2, 28359, Bremen, Germany.
authors.forename: Kai
authors.initials: K
authors.lastname: Bischof
mesh_terms: D000064:Acclimatization / Q000528:radiation effects; D000975:Antioxidants / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D005227:Fatty Acids / Q000378:metabolism; D005453:Fluorescence; D044423:Kelp / Q000502:physiology* / Q000528:radiation effects; D008027:Light; D044662:Macrocystis / Q000502:physiology* / Q000528:radiation effects; D010788:Photosynthesis / Q000528:radiation effects; D045332:Photosystem II Protein Complex / Q000378:metabolism; D025341:Principal Component Analysis; D012995:Solubility; D013634:Tannins / Q000378:metabolism; D013997:Time Factors; D024341:Xanthophylls / Q000378:metabolism
chemical_list: D000975:Antioxidants; D005227:Fatty Acids; D045332:Photosystem II Protein Complex; D013634:Tannins; D024341:Xanthophylls; D002734:Chlorophyll; D000077194:Chlorophyll A
keywords: Chile; PAR; acclimation; antioxidants; fatty acid composition; phlorotannins; temperature; total lipids