title: Photoacclimation of photosynthesis in the Eustigmatophycean Nannochloropsis gaditana.
abstract: Nannochloropsis is an eukaryotic alga of the phylum Heterokonta, originating from a secondary endosymbiotic event. In this work, we investigated how the photosynthetic apparatus responds to growth in different light regimes in Nannochloropsis gaditana. We found that intense illumination induces the decrease of both photosystem I and II contents and their respective antenna sizes. Cells grown in high light showed a larger capacity for electron transport, with enhanced cyclic electron transport around photosystem I, contributing to photoprotection from excess illumination. Even when exposed to excess light intensities for several days, N. gaditana cells did not activate constitutive responses such as nonphotochemical quenching and the xanthophyll cycle. These photoprotection mechanisms in N. gaditana thus play a role in acclimation to fast changes in illumination within a time range of minutes, while regulation of the electron flow capacity represents a long-term response to prolonged exposure to excess light.
authors.affiliation: Dipartimento di Biologia, Università di Padova, Via U. Bassi 58/B, 35121, Padua, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Meneghesso
authors.affiliation: Dipartimento di Biologia, Università di Padova, Via U. Bassi 58/B, 35121, Padua, Italy.
authors.forename: Diana
authors.initials: D
authors.lastname: Simionato
authors.affiliation: Dipartimento di Biologia, Università di Padova, Via U. Bassi 58/B, 35121, Padua, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Gerotto
authors.affiliation: Dipartimento di Biologia, Università di Padova, Via U. Bassi 58/B, 35121, Padua, Italy.
authors.forename: Nicoletta
authors.initials: N
authors.lastname: La Rocca
authors.affiliation: Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Université Grenoble Alpes, Institut National Recherche Agronomique (INRA), Institut de Recherche en Sciences et Technologies pour le Vivant (iRTSV), CEA Grenoble, 38054, Grenoble Cedex 9, France.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Finazzi
authors.affiliation: Dipartimento di Biologia, Università di Padova, Via U. Bassi 58/B, 35121, Padua, Italy. tomas.morosinotto@unipd.it.
authors.forename: Tomas
authors.identifier: http://orcid.org/0000-0002-0803-7591
authors.initials: T
authors.lastname: Morosinotto
mesh_terms: D000064:Acclimatization; D004579:Electron Transport / Q000528:radiation effects; D008027:Light; D010788:Photosynthesis / Q000528:radiation effects; D045331:Photosystem I Protein Complex / Q000378:metabolism*; D045332:Photosystem II Protein Complex / Q000378:metabolism*; D058009:Stramenopiles / Q000502:physiology* / Q000528:radiation effects; D024341:Xanthophylls / Q000378:metabolism
chemical_list: D045331:Photosystem I Protein Complex; D045332:Photosystem II Protein Complex; D024341:Xanthophylls
keywords: Acclimation; Cyclic electron flow; Microalgae; Nonphotochemical quenching; Photoprotection