Molecular basis of chromatic adaptation in pennate diatom Phaeodactylum tricornutum.
The remarkable adaptability of diatoms living in a highly variable environment assures their prominence among marine primary producers. The present study integrates biochemical, biophysical and genomic data to bring new insights into the molecular mechanism of chromatic adaptation of pennate diatoms in model species Phaeodactylum tricornutum, a marine eukaryote alga possessing the capability to shift its absorption up to ~700 nm as a consequence of incident light enhanced in the red component. Presence of these low energy spectral forms of Chl a is manifested by room temperature fluorescence emission maximum at 710 nm (F710). Here we report a successful isolation of the supramolecular protein complex emitting F710 and identify a member of the Fucoxanthin Chlorophyll a/c binding Protein family, Lhcf15, as its key building block. This red-shifted antenna complex of P. tricornutum appears to be functionally connected to photosystem II. Phylogenetic analyses do not support relation of Lhcf15 of P. tricornutum to other known red-shifted antenna proteins thus indicating a case of convergent evolutionary adaptation towards survival in shaded environments.
Institute of Plant Molecular Biology, Biology Centre CAS, Branisovska 31, 37005 Ceske Budejovice, Czech Republic; Faculty of Science, University of South Bohemia, Branisovska 1760, 37005 Ceske Budejovice, Czech Republic.
Miroslava
M
Herbstová
Institute of Plant Molecular Biology, Biology Centre CAS, Branisovska 31, 37005 Ceske Budejovice, Czech Republic; Faculty of Science, University of South Bohemia, Branisovska 1760, 37005 Ceske Budejovice, Czech Republic.
David
D
Bína
Faculty of Science, University of South Bohemia, Branisovska 1760, 37005 Ceske Budejovice, Czech Republic.
Peter
P
Koník
Institute of Plant Molecular Biology, Biology Centre CAS, Branisovska 31, 37005 Ceske Budejovice, Czech Republic; Faculty of Science, University of South Bohemia, Branisovska 1760, 37005 Ceske Budejovice, Czech Republic.
Zdenko
Z
Gardian
Institute of Plant Molecular Biology, Biology Centre CAS, Branisovska 31, 37005 Ceske Budejovice, Czech Republic; Faculty of Science, University of South Bohemia, Branisovska 1760, 37005 Ceske Budejovice, Czech Republic.
František
F
Vácha
Institute of Plant Molecular Biology, Biology Centre CAS, Branisovska 31, 37005 Ceske Budejovice, Czech Republic; Faculty of Science, University of South Bohemia, Branisovska 1760, 37005 Ceske Budejovice, Czech Republic. Electronic address: litvin@umbr.cas.cz.
Radek
R
Litvín
D000222:Adaptation, Physiological; D002734:Chlorophyll / Q000378:metabolism*; D000077194:Chlorophyll A; D003116:Color; D017377:Diatoms / Q000502:physiology*; D005453:Fluorescence; D008027:Light; D045342:Light-Harvesting Protein Complexes / Q000378:metabolism*; D045332:Photosystem II Protein Complex / Q000378:metabolism*; D010802:Phylogeny; D013050:Spectrometry, Fluorescence; D021241:Spectrometry, Mass, Electrospray Ionization
D045342:Light-Harvesting Protein Complexes; D045332:Photosystem II Protein Complex; D002734:Chlorophyll; D000077194:Chlorophyll A
Chromatic adaptation; Diatom; Heterokonta; Light harvesting antenna; Phaeodactylum tricornutum; Red-shifted antenna complex