Seasonal patterns in Synechococcus pigment diversity at two temperate sites with contrasting oceanic regimes
Year: 2026
Type: preprint
Abstract: ABSTRACT Competition for light has driven extensive pigment diversification among phytoplankton species, yet how this diversity shapes their spatiotemporal distribution in the field has been little studied so far. The cyanobacterium Synechococcus is an ideal model for addressing this issue, since this group has colonized most light spectral niches in marine environments. Here, we used an approach based on marker read recruitment from metagenomes to analyze the seasonal succession of Synechococcus pigment types (PTs) at two time-series stations off French coasts exhibiting contrasting oceanic regimes. Marked seasonality was observed at both sites. The shallow, permanently mixed English Channel site SOMLIT-Astan was characterized by an alternation between green-light specialists (PT 3a) peaking in spring, and chromatic acclimaters type A (PT 3dA) accounting for most of the Synechococcus community in winter. In contrast, the pigment diversity was much higher at the deep Mediterranean station BOUSSOLE. In the upper layer, the two main PTs were the blue light specialists (PT 3c), which dominated the community in summer and fall, and PT 3dA cells, which were more abundant in spring. The third most abundant PT was chromatic acclimaters type B (PT 3dB), which accounted for up to 15% of the surface community in late fall. Strikingly, PT 3dA was dominant at depth during most of the year. Multivariate analyses between PT abundances, clade abundances and environmental factors, notably water color indexes, suggested new associations between PTs to specific clades and ecological niches. This study provides novel insights for refining distribution models of Synechococcus PTs and phytoplankton groups in general.
Authors: Louison Dufour, Emile Faure, Frédéric Partensky, Francesco Mattei, Julia Uitz, Flavien Petit, Vincenzo Vellucci, Melek Golbol, Morgane Ratin, Bastian Gouriou, Martin Gachenot, Julia Clairet, Gregory K. Farrant, Mark Hoebeke, Erwan Corre, David Antoine, Anne-Claire Baudoux, Estelle Bigeard, Sarah Bureau, Jade Castel, Aurélie Chambouvet, Douglas Couet, Romain Cre’hriou, Colomban de Vargas, Céline Dimier, Florence Le Gall, Laure Guillou, Nicolas Henry, Fabienne Rigaut-Jalabert, Christian Jeanthon, Sarah Romac, Nathalie Simon, Jérémy Szymczak, Clara Trellu, Marie Walde, Anna Hickman, Stephanie Dutkiewicz, David M. Kehoe, Fabrice Not, Eric Thiébaut, Laurence Garczarek
Institutions: Centre National de la Recherche Scientifique, Czech Academy of Sciences, Station Biologique de Roscoff, Sorbonne Université, Adaptation et Diversité en Milieu Marin, Czech Academy of Sciences, Institute of Microbiology, University of Bristol, National Oceanography Centre, Laboratoire d’Océanographie de Villefranche, Institut de la Mer de Villefranche, Institut Pierre-Simon Laplace, Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques, Institut de Recherche pour le Développement, Structure et Instabilité des Génomes, Ifremer, Université de Bretagne Occidentale, Institut Universitaire Européen de la Mer, Laboratoire des Sciences de l'Environnement Marin, Curtin University, University of Southampton, Massachusetts Institute of Technology, Indiana University Bloomington, Indiana University
Language: English
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
SDG: Life below water
Open Access status: green
OpenAlex ID: W7168143005