A Jonathan Shaw1, Nicolas Devos2, Yang Liu3, Cymon J Cox4, Bernard Goffinet3, Kjell Ivar Flatberg5, Blanka Shaw2. 1. Department of Biology, Duke University, Durham, NC 27708, USA shaw@duke.edu. 2. Department of Biology, Duke University, Durham, NC 27708, USA. 3. Department of Ecology and Evolutionary Biology, 75 North Eagleville Road, Storrs, CT 06269, USA. 4. Centro de Ciências do Mar, Universidade do Algarve, Campus de Gambelas, Edif. 7, 8005-139 Faro, Portugal. 5. NTNU University Museum, Norwegian University of Science and Technology, N-7491 Trondheim, Norway.
Abstract
BACKGROUND AND AIMS: Sphagnum-dominated peatlands contain approx. 30 % of the terrestrial carbon pool in the form of partially decomposed plant material (peat), and, as a consequence, Sphagnum is currently a focus of studies on biogeochemistry and control of global climate. Sphagnum species differ in ecologically important traits that scale up to impact ecosystem function, and sequencing of the genome from selected Sphagnum species is currently underway. As an emerging model system, these resources for Sphagnum will facilitate linking nucleotide variation to plant functional traits, and through those traits to ecosystem processes. A solid phylogenetic framework for Sphagnum is crucial to comparative analyses of species-specific traits, but relationships among major clades within Sphagnum have been recalcitrant to resolution because the genus underwent a rapid radiation. Herein a well-supported hypothesis for phylogenetic relationships among major clades within Sphagnum based on organellar genome sequences (plastid, mitochondrial) is provided. METHODS: We obtained nucleotide sequences (273 753 nucleotides in total) from the two organellar genomes from 38 species (including three outgroups). Phylogenetic analyses were conducted using a variety of methods applied to nucleotide and amino acid sequences. The Sphagnum phylogeny was rooted with sequences from the related Sphagnopsida genera, Eosphagnum and Flatbergium KEY RESULTS: Phylogenetic analyses of the data converge on the following subgeneric relationships: (Rigida (((Subsecunda) (Cuspidata)) ((Sphagnum) (Acutifolia))). All relationships were strongly supported. Species in the two major clades (i.e. Subsecunda + Cuspidata and Sphagnum + Acutifolia), which include >90 % of all Sphagnum species, differ in ecological niches and these differences correlate with other functional traits that impact biogeochemical cycling. Mitochondrial intron presence/absence are variable among species and genera of the Sphagnopsida. Two new nomenclatural combinations are made, in the genera Eosphagnum and Flatbergium CONCLUSIONS: Newly resolved relationships now permit phylogenetic analyses of morphological, biochemical and ecological traits among Sphagnum species. The results clarify long-standing disagreements about subgeneric relationships and intrageneric classification.
BACKGROUND AND AIMS: Sphagnum-dominated peatlands contain approx. 30 % of the terrestrial carbon pool in the form of partially decomposed plant material (peat), and, as a consequence, Sphagnum is currently a focus of studies on biogeochemistry and control of global climate. Sphagnum species differ in ecologically important traits that scale up to impact ecosystem function, and sequencing of the genome from selected Sphagnum species is currently underway. As an emerging model system, these resources for Sphagnum will facilitate linking nucleotide variation to plant functional traits, and through those traits to ecosystem processes. A solid phylogenetic framework for Sphagnum is crucial to comparative analyses of species-specific traits, but relationships among major clades within Sphagnum have been recalcitrant to resolution because the genus underwent a rapid radiation. Herein a well-supported hypothesis for phylogenetic relationships among major clades within Sphagnum based on organellar genome sequences (plastid, mitochondrial) is provided. METHODS: We obtained nucleotide sequences (273 753 nucleotides in total) from the two organellar genomes from 38 species (including three outgroups). Phylogenetic analyses were conducted using a variety of methods applied to nucleotide and amino acid sequences. The Sphagnum phylogeny was rooted with sequences from the related Sphagnopsida genera, Eosphagnum and Flatbergium KEY RESULTS: Phylogenetic analyses of the data converge on the following subgeneric relationships: (Rigida (((Subsecunda) (Cuspidata)) ((Sphagnum) (Acutifolia))). All relationships were strongly supported. Species in the two major clades (i.e. Subsecunda + Cuspidata and Sphagnum + Acutifolia), which include >90 % of all Sphagnum species, differ in ecological niches and these differences correlate with other functional traits that impact biogeochemical cycling. Mitochondrial intron presence/absence are variable among species and genera of the Sphagnopsida. Two new nomenclatural combinations are made, in the genera Eosphagnum and Flatbergium CONCLUSIONS: Newly resolved relationships now permit phylogenetic analyses of morphological, biochemical and ecological traits among Sphagnum species. The results clarify long-standing disagreements about subgeneric relationships and intrageneric classification.
Authors: David J Weston; Collin M Timm; Anthony P Walker; Lianhong Gu; Wellington Muchero; Jeremy Schmutz; A Jonathan Shaw; Gerald A Tuskan; Jeffrey M Warren; Stan D Wullschleger Journal: Plant Cell Environ Date: 2014-12-07 Impact factor: 7.228
Authors: A Jonathan Shaw; Cymon J Cox; William R Buck; Nicolas Devos; Alex M Buchanan; Lynette Cave; Rodney Seppelt; Blanka Shaw; Juan Larraín; Richard Andrus; Johann Greilhuber; Eva M Temsch Journal: Am J Bot Date: 2010-08-06 Impact factor: 3.844
Authors: Robert K Jansen; Zhengqiu Cai; Linda A Raubeson; Henry Daniell; Claude W Depamphilis; James Leebens-Mack; Kai F Müller; Mary Guisinger-Bellian; Rosemarie C Haberle; Anne K Hansen; Timothy W Chumley; Seung-Bum Lee; Rhiannon Peery; Joel R McNeal; Jennifer V Kuehl; Jeffrey L Boore Journal: Proc Natl Acad Sci U S A Date: 2007-11-28 Impact factor: 11.205
Authors: Sergey Y Morozov; Irina A Milyutina; Tatiana N Erokhina; Liudmila V Ozerova; Alexey V Troitsky; Andrey G Solovyev Journal: PeerJ Date: 2018-04-16 Impact factor: 2.984