Peatmoss (Sphagnum) diversification associated with Miocene Northern Hemisphere climatic cooling?

Shaw, A. Jonathan; Devos, Nicolas; Cox, Cymon J.; Boles, Sandra B.; Shaw, Blanka; Buchanan, Alex M.; Cave, Lynette; Seppelt, R. D.

doi:10.1016/j.ympev.2010.01.020

Cited by 86 publications

(79 citation statements)

References 34 publications

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“…Their estimates, albeit crude, suggest that the Sphagnopsida is an ancient group and diverged from the Takakiopsida between 129 and 319 million years ago (Ma), and the Flatbergiaceae plus Ambuchananiaceae diverged from the Sphagnaceae between 34 and 104 Ma. The diversifi cation of extant Sphagnum species, in contrast, occurred relatively recently, between seven and 20 Ma, possibly associated with climatic cooling of the northern hemisphere and origin of boreal vegetation during the Miocene ( Shaw et al, 2010 ).…”

Section: Discussionmentioning

confidence: 99%

“…The 60-taxon, 8-locus data set was used in a companion paper ( Shaw et al, 2010 ) to the present one, describing the timeframe of diversifi cation in Sphagnopsida, and GenBank accession numbers were reported in that paper. For the sake of completeness, all GenBank numbers, including those previously published as well as those newly generated for this paper, are provided in Appendix 1.…”

Section: Methodsmentioning

confidence: 99%

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Newly resolved relationships in an early land plant lineage: Bryophyta class Sphagnopsida (peat mosses)

Shaw

Cox

Buck

et al. 2010

American J of Botany

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Phylogenetic analyses of genome structure and nucleotide sequences from mitochondrial, plastid, and nuclear genes have corroborated the view held by botanists for over a century that the bryophyte groups (mosses, liverworts, hornworts) comprise early-diverging land plant lineages that originated before the appearance of vascular plants ( Haeckel, 1876 ;Campbell, 1895 ;Bower, 1935 ;Kenrick and Crane, 1997 ;Shaw and Renzaglia, 2004 ). Early cladistic analyses based on morphological characters ( Mishler and Churchill, 1984 ) showed that the three bryophyte groups, classifi ed by most botanists of the time as a single phylum because of their similar gametophyte-dominant life cycles, more likely represent a paraphyletic grade that diverged before the emergence of the vascular plants. In fact, Haeckel ' s (1876) tree similarly shows mosses and liverworts as a paraphyletic grade basal to the vascular plants. Recent data sets appear to favor the hypothesis that liverworts (phylum Marchantiophyta) comprise the earliest-diverging lineage, followed by the mosses (Bryophyta) and hornworts (Anthocerophyta) ( Qiu et al., 1998 ;Nickrent et al., 2000 ;Shaw and Renzaglia, 2004 ). However, the most data-rich studies to date, based on chloroplast or mitochondrial organellar proteins, like analyses based on sperm cell morphology ( Garbary et al., 1993 ), identify a clade uniting liverworts and mosses, and additional data are still needed before we can consider the branching order of early land plant lineages to be fi nally resolved ( Nishiyama et al., 2004 ;Rodr í guez-Ezpeleta et al., 2007 ;Terasawa et al., 2007 ; but see also Qiu, et al., 2006 ).Notwithstanding that much remains to do, great progress has been made toward resolving phylogenetic relationships within the mosses (phylum Bryophyta s.s.) (e.g., Cox and Hedderson, 1999 ;Cox et al., 2000 ;Newton et al., 2000 ; Goffi net et al., 2001 ;Stech and Frey, 2008 ; Goffi net et al., 2009 ;Wahrmund et al., 2010 ). Major clades resolved by molecular data to a large extent mirror previous classifi cations based on morphology (e.g., Fleischer, 1923 ; Brotherus, 1924 Brotherus, -1925Vitt, 1984 • Premise of the study : The Sphagnopsida, an early-diverging lineage of mosses (phylum Bryophyta), are morphologically and ecologically unique and have profound impacts on global climate. The Sphagnopsida are currently classifi ed in two genera, Sphagnum (peat mosses) with some 350 -500 species and Ambuchanania with one species. An analysis of phylogenetic relationships among species and genera in the Sphagnopsida were conducted to resolve major lineages and relationships among species within the Sphagnopsida.• Methods : Phylogenetic analyses of nucleotide sequences from the nuclear, plastid, and mitochondrial genomes (11 704 nucleotides total) were conducted and analyzed using maximum likelihood and Bayesian inference employing seven different substitution models of varying complexity.• Key results : Phylogenetic analyses resolved three lineages within the Sphagnopsida: (1) Sphagnum serice...

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Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Newly resolved relationships in an early land plant lineage: Bryophyta class Sphagnopsida (peat mosses)

Shaw

Cox

Buck

et al. 2010

American J of Botany

Self Cite

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“…We also carried out runs that removed one calibration fossil at a time, leaving only the vascular plant constraint. An additional analysis was conducted using a mean substitution rate across mitochondrial, nuclear, and plastid genomes of 3 × 10 −4 substitutions per site per million years (55).…”

Section: Methodsmentioning

confidence: 99%

Hornwort pyrenoids, carbon-concentrating structures, evolved and were lost at least five times during the last 100 million years

Villarreal

Renner

2012

Proc. Natl. Acad. Sci. U.S.A.

113

105

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Ribulose-1,5-Biphosphate-carboxylase-oxygenase (RuBisCO) has a crucial role in carbon fixation but a slow catalytic rate, a problem overcome in some plant lineages by physiological and anatomical traits that elevate carbon concentrations around the enzyme. Such carbon-concentrating mechanisms are hypothesized to have evolved during periods of low atmospheric CO 2 . Hornworts, the sister to vascular plants, have a carbon-concentrating mechanism that relies on pyrenoids, proteinaceous bodies mostly consisting of RuBisCO. We generated a phylogeny based on mitochondrial and plastid sequences for 36% of the approximately 200 hornwort species to infer the history of gains and losses of pyrenoids in this clade; we also used fossils and multiple dating approaches to generate a chronogram for the hornworts. The results imply five to six origins and an equal number of subsequent losses of pyrenoids in hornworts, with the oldest pyrenoid gained ca. 100 Mya, and most others at <35 Mya. The nonsynchronous appearance of pyrenoid-containing clades, the successful diversification of pyrenoid-lacking clades during periods with low [CO 2 ], and the maintenance of pyrenoids during episodes of high [CO 2 ] all argue against the previously proposed relationship between pyrenoid origin and low [CO 2 ]. The selective advantages, and costs, of hornwort pyrenoids thus must relate to additional factors besides atmospheric CO 2 . independent origins T he enzyme most important in photosynthesis is Ribulose-1,5-Biphosphate-carboxylase-oxygenase, or RuBisCO. This enzyme has a low CO 2 attraction and catalytic rate, which plants compensate for by increasing their CO 2 affinity, synthesizing large quantities of the enzyme, or increasing the CO 2 concentration near it (1-3). Among green organisms (algae and land plants), CO 2 -concentrating mechanisms (CCMs, also referred to as carbonconcentrating mechanisms) have evolved in numerous lineages to increase the CO 2 :O 2 ratio inside their photosynthetic cells. These mechanisms are C 4 photosynthesis, Crassulacean acid metabolism, and the pyrenoids found in algae and hornworts (4, 5).

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“…The same primers were used in different groups of mosses, especially Sphagnum (e.g. Shaw et al 2003Shaw et al , 2010), from family and genus level (e.g. Shaw et al 2008a) to species and intraspecific levels (e.g.…”

Section: Plastid Genome Markersmentioning

confidence: 99%

20,000 species and five key markers: The status of molecular bryophyte phylogenetics

Stech¹,

Quandt²

2014

Phytotaxa

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A number of reviews have accompanied and monitored the progress of molecular phylogenetic research on bryophytes, focusing on the publication record itself, bryophyte phylogeny and systematics in the molecular era, as well as the evolution and phylogenetic utility of markers from different genomes. However, none of the recent reviews include a detailed characterization of all molecular markers used in bryophyte phylogenetics. Here we provide an overview of the history and current state of marker utilization, including coding and non-coding sequence markers from all three genomes as well as fingerprinting approaches. The molecular architecture and evolutionary peculiarities, as well as practical aspects such as amplification and sequencing strategies, are outlined for the DNA sequence markers, with a focus on the most commonly employed regions. Their phylogenetic utility and potential for solving some of the remaining, pressing questions in bryophyte phylogeny, as well as their suitability for molecular species identification by DNA barcoding, are discussed.

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Peatmoss (Sphagnum) diversification associated with Miocene Northern Hemisphere climatic cooling?

Cited by 86 publications

References 34 publications

Newly resolved relationships in an early land plant lineage: Bryophyta class Sphagnopsida (peat mosses)

Newly resolved relationships in an early land plant lineage: Bryophyta class Sphagnopsida (peat mosses)

Hornwort pyrenoids, carbon-concentrating structures, evolved and were lost at least five times during the last 100 million years

20,000 species and five key markers: The status of molecular bryophyte phylogenetics

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