title: Photoprotective and antioxidant responses to light spectrum and intensity variations in the coastal diatom Skeletonema marinoi.
abstract: Photosynthesis is known to produce reactive oxygen species together with the transformation of light into biochemical energy. To fill the gap of the knowledge on the protective antioxidant network of microalgae, a series of experiments to explore the role of spectral composition and intensity of light in the modulation of the photodefence mechanisms developed by the coastal diatom Skeletonema marinoi were performed. The modulation of the total phenolic content, ascorbic acid and the enzymes glutathione reductase, catalase, ascorbate peroxidase and superoxide dismutase together with xanthophyll cycle and non-photochemical quenching in response to variations in the light environment were analysed. Most of the enzymes' activity was promptly affected by the red light. Yet, the monochromatic high intensity blue light enhanced the synthesis of total phenolic content and ascorbic acid in parallel to the xanthophyll cycle activity. This study reveals the dual effects of spectral composition and intensity of light on the modulation of photoprotective mechanisms. Diatoms developed a complementary and/or alternative tuning processes to cope with the variable light environment they experience in the water column. They also provided valuable insights into light manipulation regimes for diatom cultivation that will help to maximize production of bioactive molecules.
authors.affiliation: Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli, 80121, Italy.
authors.forename: Arianna
authors.initials: A
authors.lastname: Smerilli
authors.affiliation: Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli, 80121, Italy.
authors.forename: Ida
authors.initials: I
authors.lastname: Orefice
authors.affiliation: Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli, 80121, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Corato
authors.affiliation: Instituto de Investigaciones Marinas CSIC, Av. Eduardo Cabello 6, Vigo, 36208, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Gavalás Olea
authors.affiliation: School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, United Kingdom.
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Ruban
authors.affiliation: Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli, 80121, Italy.
authors.forename: Christophe
authors.initials: C
authors.lastname: Brunet
mesh_terms: D000975:Antioxidants; D002374:Catalase; D017377:Diatoms / Q000201:enzymology / Q000502:physiology* / Q000528:radiation effects*; D015971:Gene Expression Regulation, Enzymologic / Q000528:radiation effects; D008027:Light; D058086:Microalgae / Q000378:metabolism; D010636:Phenols / Q000378:metabolism; D010788:Photosynthesis / Q000502:physiology; D017382:Reactive Oxygen Species; D013482:Superoxide Dismutase; D024341:Xanthophylls
chemical_list: D000975:Antioxidants; D010636:Phenols; D017382:Reactive Oxygen Species; D024341:Xanthophylls; D002374:Catalase; D013482:Superoxide Dismutase