Red-light phenotype in a marine diatom involves a specialized oligomeric red-shifted antenna and altered cell morphology

• Published in: Scientific reports 2017-09, Vol.7 (1), p.11976-10, Article 11976
• Main Authors: Herbstová, Miroslava, Bína, David, Kaňa, Radek, Vácha, František, Litvín, Radek
• Format: Article
• Language: English
• Subjects: 14/19; 631/449/1734/2077; 631/449/2686; 631/45/612/1237; 631/57/1464; 82/16; 82/29; 82/58; 82/83; Acclimation; Acclimatization; Adaptation, Physiological; Aquatic Organisms - physiology; Aquatic Organisms - radiation effects; Bacillariophyta; Carbon fixation; Cell culture; Cell morphology; Cytology; Diatoms - physiology; Diatoms - radiation effects; Humanities and Social Sciences; Light-Harvesting Protein Complexes - metabolism; multidisciplinary; Phenotype; Photosynthetic apparatus; Plankton; Protein Multimerization; Science; Science (multidisciplinary); Spectrum Analysis
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-017-12247-0

Diatoms greatly contribute to carbon fixation and thus strongly influence the global biogeochemical balance. Capable of chromatic acclimation (CA) to unfavourable light conditions, diatoms often dominate benthic ecosystems in addition to their planktonic lifestyle. Although CA has been studied at the molecular level, our understanding of this phenomenon remains incomplete. Here we provide new data to better explain the acclimation-associated changes under red-enhanced ambient light (RL) in diatom Phaeodactylum tricornutum , known to express a red-shifted antenna complex (F710). The complex was found to be an oligomer of a single polypeptide, Lhcf15. The steady-state spectroscopic properties of the oligomer were also studied. The oligomeric assembly of the Lhcf15 subunits is required for the complex to exhibit a red-shifted absorption. The presence of the red antenna in RL culture coincides with the development of a rounded phenotype of the diatom cell. A model summarizing the modulation of the photosynthetic apparatus during the acclimation response to light of different spectral quality is proposed. Our study suggests that toggling between alternative organizations of photosynthetic apparatus and distinct cell morphologies underlies the remarkable acclimation capacity of diatoms.