title: Dynamics of Viral Abundance and Diversity in a Sphagnum-Dominated Peatland: Temporal Fluctuations Prevail Over Habitat.
abstract: Viruses impact microbial activity and carbon cycling in various environments, but their diversity and ecological importance in Sphagnum-peatlands are unknown. Abundances of viral particles and prokaryotes were monitored bi-monthly at a fen and a bog at two different layers of the peat surface. Viral particle abundance ranged from 1.7 x 10(6) to 5.6 x 10(8) particles mL(-1), and did not differ between fen and bog but showed seasonal fluctuations. These fluctuations were positively correlated with prokaryote abundance and dissolved organic carbon, and negatively correlated with water-table height and dissolved oxygen. Using shotgun metagenomics we observed a shift in viral diversity between winter/spring and summer/autumn, indicating a seasonal succession of viral communities, mainly driven by weather-related environmental changes. Based on the seasonal asynchrony between viral and microbial diversity, we hypothesize a seasonal shift in the active microbial communities associated with a shift from lysogenic to lytic lifestyles. Our results suggest that temporal variations of environmental conditions rather than current habitat differences control the dynamics of virus-host interactions in Sphagnum-dominated peatlands.
authors.affiliation: UMR CNRS 6553 ECOBIO, Université de Rennes 1 Rennes, France.
authors.forename: Flore
authors.initials: F
authors.lastname: Ballaud
authors.affiliation: UMR CNRS 6553 ECOBIO, Université de Rennes 1 Rennes, France.
authors.forename: Alexis
authors.initials: A
authors.lastname: Dufresne
authors.affiliation: UMR CNRS 6553 ECOBIO, Université de Rennes 1 Rennes, France.
authors.forename: André-Jean
authors.initials: AJ
authors.lastname: Francez
authors.affiliation: Université Clermont Auvergne, Université Blaise PascalClermont-Ferrand, France; CNRS, UMR 6023, Laboratoire Microorganismes: Génome et EnvironnementAubière, France.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Colombet
authors.affiliation: Université Clermont Auvergne, Université Blaise PascalClermont-Ferrand, France; CNRS, UMR 6023, Laboratoire Microorganismes: Génome et EnvironnementAubière, France.
authors.forename: Télesphore
authors.initials: T
authors.lastname: Sime-Ngando
authors.affiliation: UMR CNRS 6553 ECOBIO, Université de Rennes 1 Rennes, France.
authors.forename: Achim
authors.initials: A
authors.lastname: Quaiser
keywords: bog; ecological succession; fen; metaviromes; microbial interactions; prokaryotes