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Phytochelatins (PCs) are cysteine-rich small peptides, enzymatically synthesized from reduced glutathione (GSH) by cytosolic enzyme phytochelatin synthase (PCS). The open reading frame (ORF) of the

18 Pág. Instituto de Ciencias Forestales (ICIFOR), Phylogenetic relationships of species within the pleurocarpous moss genus Neckera s.l. (Neckeraceae) are reconstructed based on three genomic regions: the plastid rps4-trnT-trnL-trnF cluster and the rpl16 group II intron, as well as the internal transcribed spacer region of the nuclear ribosomal DNA (ITS1-5.8S-ITS2). The phylogenetic reconstruction suggests numerous taxonomic changes within the Neckeraceae. Two unispecific Asian genera are described as new: Taiwanobryopsis to accommodate Neckera warburgii, and Indoneckera to accommodate Neckera himalayana. Seven of the other "Neckera"species, all distributed in Asia, are transferred to Forsstroemia, and a further four Asian species to Taiwanobryum. Six Southern Hemisphere or tropical species (one from New Zealand, one from Africa, four from South America) are transferred to Alleniella. After these adjustments, Neckera becomes a northern hemisphere, mainly temperate, genus of c. 10 species that are absent from the tropics. It is in this context morphologically characterized by lack of paraphyllia (except N. californica) and an absent or weak costa. Alleniella has two species - the first diverging lineages - in the northern hemisphere, but the rest of the currently 15 species are distributed in the southern hemisphere and most of the species occur in mountain habitats in the tropics; it is however absent from tropical Asia and very scarce in Asia in general. Twelve of the 15 species have paraphyllia, which is the clearest morphological distinction from Neckera. Forsstroemia with 19 species, heavily concentrated in Asia, is the largest genus in the Neckeraceae. Clearly longer and more distinct costa distinguishes the genus from Neckera and Alleniella. Taiwanobryum is a morphologically heterogeneous Asian genus of nine species. Neckera decurrens Broth. is synonymized with Forsstroemia fauriei and Neckera valentiniana Besch. with Alleniella ehrenbergii. ©, We acknowledge funding by the German Science Foundation (DFG QU 153/3-1, QU 153/3-2, QU 153/8-1).

Centro de Investigación Forestal (CIFOR), Nonrecombining sex chromosomes, like the mammalian Y, often lose genes and accumulate transposable ele ments, a process termed degeneration. The correlation between suppressed recombination and degeneration is clear in animal XY systems, but the absence of recombination is confounded with other asymmetries between the X and Y. In contrast, UV sex chromosomes, like those found in bryophytes, experience symmetrical population genetic conditions. Here, we generate nearly gapless female and male chromosome-scale reference genomes of the moss Ceratodon purpureus to test for degeneration in the bryophyte UV sex chromosomes. We show that the moss sex chromosomes evolved over 300 million years ago and expanded via two chromosomal fusions. Although the sex chromosomes exhibit weaker purifying selection than autosomes, we find that suppressed recombination alone is insufficient to drive degeneration. Instead, the U and V sex chromosomes harbor thousands of broadly expressed genes, including numerous key regulators of sexual development across land plants., This work was supported by NSF DEB-1541005 and 1542609 and start-up funds from UF to S.F.M.; microMORPH Cross-Disciplinary Training Grant, Sigma-Xi Grant-In-Aid of Research, and Society for the Study of Evolution Rosemary Grant Award to S.B.C.; NSF DEB-1239992 to N.J.W.; the Emil Aaltonen Foundation and the University of Turku to S.O.; and NSF DEB-1541506 to J.G.B. and S.F.M. The work conducted by the U.S. Department of Energy Joint Genome Institute was supported by the Office of Science of the U.S. Department of Energy under contract no. DE-AC02-05CH11231., 12 Pág. Supplementary material for this article is available at http://advances.sciencemag.org/cgi/ content/full/7/27/eabh2488/DC1

Wide-range geographically discontinuous distributions have long intrigued scientists. We explore the role of ecology, geology, and dispersal in the formation of these large-scale disjunctions, using the angiosperm tribe Putorieae (Rubiaceae) as a case study. From DNA sequences of nuclear ITS and six plastid markers, we inferred a phylogeny with 65% of all known Putorieae species. Divergence times, ancestral ranges, and diversification rate shifts were then estimated using Bayesian inference. We further explored species climatic tolerances and performed ancestral niche reconstruction to discriminate among alternative speciation modes, including geographical and ecological vicariance, and ecogeographical, ecological, and dispersal-mediated speciation. As a result, we identified seven major clades in Putorieae, some of which exhibit striking geographical disjunctions, matching the Rand Flora pattern, with sister species in the Canary Islands and eastern and southern Africa. Initial diversification within the tribe occurred in the early Miocene, coincident with a period of climate warming; however, most clades diverged within the last 10 Myr. Aridification and high extinction rates, coupled with ecological vicariance, explain the oldest disjunctions. Adaptation to new environmental conditions, after allopatry, is observed in several clades. Dispersal, either long-distance or via corridors made available by mountain uplift, is behind the most recent disjunctions. Some of these events were followed by ecological speciation and rapid diversification, with species becoming adapted to xeric or increasingly colder continental climates. We show that an integrative approach may help discriminate among speciation modes invoked to explain disjunctions at macroevolutionary time scales, even when extinction has erased the signature of past events., Funding was provided by the Spanish Government, through grants CGL2015-67849-P (MINECO/FEDER) to IS. MR was supported by a MINECO FPI Fellowship (BES-2013-065389), jointly supervised by IS and RR. RR was supported by grant CGL2015-73621-JIN (AEI/FEDER). LP was supported through an EU-funded SYNTHESYS3 grant (GB-TAF-5153). The authors acknowledge the CIPRES portal for computational resources, Dietmar Quandt for assistance with petBD alignment, and the E, K, and MA herbaria for access to their collections.

Pines growing in the Mediterranean Basin form a heterogeneous assembly despite sharing a common past history. Because of their ecological and economic importance it is of special interest to understand their evolution through time and space. Here, we review the last advances in phylogenetic relationships among Mediterranean pines, as well as their common phylogeographic and demographic histories in response to spatial and temporal variations in climate and fire regimes, along with their specific evolutionary trajectories. We also review the knowledge accumulated during recent decades in relation to the adaptation of Mediterranean pines in an evolving world: the evolutionary path of key traits and the genomic basis of adaptive variation, both central to understanding the past evolutionary success of Mediterranean pines, their current situation and their future response to environmental changes.

Premise: Genera that are widespread, with geographically discontinuous distributions and represented by few species, are intriguing. Is their achieved disjunct distribution recent or ancient in origin? Why are they species-poor? The Rand Flora is a continental-scale pattern in which closely related species appear codistributed in isolated regions over the continental margins of Africa. Genus Camptoloma (Scrophulariaceae) is the most notable example, comprising three species isolated from each other on the northwest, eastern, and southwest Africa. Methods: We employed Sanger sequencing of nuclear and plastid markers, together with genomic target sequencing of 2190 low-copy nuclear genes, to infer interspecies relationships and the position of Camptoloma within Scrophulariaceae by using supermatrix and multispecies-coalescent approaches. Lineage divergence times and ancestral ranges were inferred with Bayesian Markov chain Monte Carlo (MCMC) approaches. The population history was estimated with phylogeographic coalescent methods. Results: Camptoloma rotundifolium, restricted to Southern Africa, was shown to be a sister species to the disjunct clade formed by C. canariense, endemic to the Canary Islands, and C. lyperiiflorum, distributed in the Horn of Africa–Southern Arabia. Camptoloma was inferred to be sister to the mostly South African tribes Teedieae and Buddlejeae. Stem divergence was dated in the Late Miocene, while the origin of the extant disjunction was inferred as Early Pliocene. Conclusions: The current disjunct distribution of Camptoloma across Africa was likely the result of fragmentation and extinction and/or population bottlenecking events associated with historical aridification cycles during the Neogene; the pattern of species divergence, from south to north, is consistent with the “climatic refugia” Rand Flora hypothesis.

Instituto de Ciencias Forestales (ICIFOR), Complementary gene-resequencing and transcriptomic approaches reveal contrasted evolutionary histories in a species complex. Pinus halepensis and Pinus brutia are closely related species that can intercross, but occupy different geographical ranges and bioclimates. To study the evolution of this species complex and to provide genomic resources for further research, we produce and analyze two new complementary sets of genetic resources: (i) a set of 172 re-sequenced genomic target loci analyzed in 45 individuals, and (ii) a set of 11 transcriptome assemblies. These two datasets provide insights congruent with previous studies: P. brutia displays high level of genetic diversity and no genetic sub-structure, while P. halepensis shows three main genetic clusters, the western Mediterranean and North African clusters displaying much lower genetic diversity than the eastern Mediterranean cluster, the latter cluster having similar genetic diversity to P. brutia. In addition, these datasets provide new insights on the timing of the species-complex history: the two species would have split at the end of the tertiary, and the changing climatic conditions of the Mediterranean region at the end of the Tertiary-beginning of the Quaternary, together with the distinct species tolerance to harsh climatic conditions would have resulted in different geographic distributions, demographic histories and genetic patterns of the two pines. The multiple glacial-interglacial cycles during the Quaternary would have led to the expansion of P. brutia in the Middle East, while P. halepensis would have been through bottlenecks. The last glaciations, from 0.6 Mya on, would have affected further the Western genetic pool of P. halepensis., Funding was provided by the Spanish Ministry of Economy and Competitiveness (MINECO) under AdapCon grant (CGL2011-30182-C02-01/02), by the project INIA-MAPAMA EG17-048 co-financed by FEADER (75%) according to EU Regulation 1305/2013 and by EVOLTREE EU-funded Network of Excellence (http://www-evoltree.eu). SO received funding from the Spanish Ministry of Economy and Competitiveness (MINECO) under PTA2015-10836-I contract. We acknowledge the Supercomputing Centre of Galicia (CESGA) as well as CSC – Finnish IT Center for the allocation of computational resources.

Non-recombining sex chromosomes, like the mammalian Y, often lose genes and accumulate transposable elements, a process termed degeneration1,2. The correlation between suppressed recombination and degeneration is clear in animal XY systems1,2, but the absence of recombination is confounded with other asymmetries between the X and Y. In contrast, UV sex chromosomes, like those found in bryophytes, experience symmetrical population genetic conditions3,4. Here we test for degeneration in the bryophyte UV sex chromosome system through genomic comparisons with new female and male chromosome-scale reference genomes of the moss Ceratodon purpureus. We show that the moss sex chromosomes evolved over 300 million years ago and expanded via two chromosomal fusions. Although the sex chromosomes show signs of weaker purifying selection than autosomes, we find suppressed recombination alone is insufficient to drive gene loss on sex-specific chromosomes. Instead, the U and V sex chromosomes harbor thousands of broadly-expressed genes, including numerous key regulators of sexual development across land plants.

International audience; European black pine (Pinus nigra J.F.Arnold) is an ecologically and economically important conifer growing across southern Europe and the Mediterranean Basin in a variety of habitats. Its morphological and ecological variabilities as well as geographic origin are the basis for subspecies level taxonomic identification and forestry practice recommendations. Yet, no true consensus exists and genomic resources are lacking for resolving the taxonomy of P. nigra and assessing its adaptive potential. To provide genetic tools for further research, we generated novel genomic resources using six de novo transcriptomic assemblies representing major biogeographic regions where the species is growing naturally. Using two closely related species, Pinus sylvestris and Pinus halepensis, as outgroups, we identified a set of 2200 nuclear, putatively orthologous, single-copy genes. In addition, we identified a set of 405,624 polymorphic SNPs for P. nigra. Based on these resources, we were able to confirm the division of P. nigra into two wide geographical population groups and to provide new insights into evolutionary dynamics of the species.

Syfte är att undersöka hur förskollärare arbetar för att stimulera barns tidiga språkutveckling. Vår arbetslivserfarenhet, egna erfarenheter samt det personliga intresset för barns språkutveckling är det som har styrt vårt val av att undersöka hur förskollärare, i förskolan, stimulerar barns tidiga språkutveckling. Det vi vill få svar på är hur begreppet språkutveckling uppfattas av förskollärare och på vilket sätt förskollärare arbetar med att stimulera barns tidiga språkutvecklingI studien har vi använt den sociokulturella teorin som utgångspunkt.För att få svar på̊ studiens forskningsfrågor har vi använt semistrukturerade intervjuer som metod. Underlaget för resultatet bygger på̊ intervjuer med 6 förskollärare som arbetar på 5 olika förskolor i 2 olika kommuner och har olika lång arbetslivserfarenhet.Resultatet visar att förskollärare arbetar med att stimulera barns språkutveckling genom att erbjuda en mångfald av olika aktiviteter i språkutvecklande lärmiljöer samt genom att ha ett förhållningssätt där de är närvarande och inlyssnande gentemot barnen. I resultatet framkommer det att förskollärarna finner det viktigt att använda sig av ett korrekt språk och att de inte förenklar språket när de samtalar med barnen. Vidare påvisar resultatet att förskollärarna anser att de har en viktig roll i att kunna tyda och sätta ord på vad barnen menar, även de som inte har språket ännu. Detta gör de genom att läsa av barnens kroppsspråk samt att de själva har ett tydligt kroppsspråk när de kommunicerar med barnen för att förstärka orden. En metod som används av samtliga förskollärare av samma anledning är TAKK (tecken som alternativ och kompletterande kommunikation).

High concentrations of heavy metals are typical of acidic environments. Therefore, studies on acidophilic organisms in their natural environments improve our understanding on the evolution of heavy metal tolerance and detoxification in plants. Here we sequenced the transcriptome of the extremophilic microalga Chlamydomonas acidophila cultivated in control conditions and with 500 μM of copper for 24 h. High-throughput 454 sequencing was followed by de novo transcriptome assembly. The reference transcriptome was annotated and genes related to heavy metal tolerance and abiotic stress were identified. Analyses of differentially expressed transcripts were used to detect genes involved in metabolic pathways related to abiotic stress tolerance, focusing on effects caused by increased levels of copper. Both transcriptomic data and observations from PAM fluorometry analysis suggested that the photosynthetic activity of C. acidophila is not adversely affected by addition of high amounts of copper. Up-regulated transcripts include several transcripts related to photosynthesis and carbohydrate metabolism, transcripts coding for general stress response, and a transcript annotated as homologous to the oil-body-associated protein HOGP coding gene. The first de novo assembly of C. acidophila significantly increases transcriptomic data available on extremophiles and green algae and thus provides an important reference for further molecular genetic studies. The differences between differentially expressed transcripts detected in our study suggest that the response to heavy metal exposure in C. acidophila is different from other studied green algae. © 2015, Springer Japan.

Reconstructing phylogenetic relationships at the micro- and macroevoutionary levels within the same tree is problematic because of the need to use different data types and analytical frameworks. We test the power of target enrichment to provide phylogenetic resolution based on DNA sequences from above species to within populations, using a large herbarium sampling and Euphorbia balsamifera (Euphorbiaceae) as a case study. Target enrichment with custom probes was combined with genome skimming (Hyb-Seq) to sequence 431 low-copy nuclear genes and partial plastome DNA. We used supermatrix, multispecies-coalescent approaches, and Bayesian dating to estimate phylogenetic relationships and divergence times. Euphorbia balsamifera, with a disjunct Rand Flora-type distribution at opposite sides of Africa, comprises three well-supported subspecies: western Sahelian sepium is sister to eastern African-southern Arabian adenensis and Macaronesian-southwest Moroccan balsamifera. Lineage divergence times support Late Miocene to Pleistocene diversification and climate-driven vicariance to explain the Rand Flora pattern. We show that probes designed using genomic resources from taxa not directly related to the focal group are effective in providing phylogenetic resolution at deep and shallow evolutionary levels. Low capture efficiency in herbarium samples increased the proportion of missing data but did not bias estimation of phylogenetic relationships or branch lengths. Reconstructing phylogenetic relationships at the micro- and macroevoutionary levels within the same tree is problematic because of the need to use different data types and analytical frameworks. We test the power of target enrichment to provide phylogenetic resolution based on DNA sequences from above species to within populations, using a large herbarium sampling and Euphorbia balsamifera (Euphorbiaceae) as a case study. Target enrichment with custom probes was combined with genome skimming (Hyb-Seq) to sequence 431 low-copy nuclear genes and partial plastome DNA. We used supermatrix, multispecies-coalescent approaches, and Bayesian dating to estimate phylogenetic relationships and divergence times. Euphorbia balsamifera, with a disjunct Rand Flora-type distribution at opposite sides of Africa, comprises three well-supported subspecies: western Sahelian sepium is sister to eastern African-southern Arabian adenensis and Macaronesian-southwest Moroccan balsamifera. Lineage divergence times support Late Miocene to Pleistocene diversification and climate-driven vicariance to explain the Rand Flora pattern. We show that probes designed using genomic resources from taxa not directly related to the focal group are effective in providing phylogenetic resolution at deep and shallow evolutionary levels. Low capture efficiency in herbarium samples increased the proportion of missing data but did not bias estimation of phylogenetic relationships or branch lengths.

To better understand heavy metal tolerance in Chlamydomonas acidophila, an extremophilic green alga, we assembled its transcriptome and measured transcriptomic expression before and after Cd exposure in this and the neutrophilic model microalga Chlamydomonas reinhardtii. Genes possibly related to heavy metal tolerance and detoxification were identified and analyzed as potential key innovations that enable this species to live in an extremely acid habitat with high levels of heavy metals. In addition we provide a data set of single orthologous genes from eight green algal species as a valuable resource for comparative studies including eukaryotic extremophiles. Our results based on differential gene expression, detection of unique genes and analyses of codon usage all indicate that there are important genetic differences in C. acidophila compared to C. reinhardtii. Several efflux family proteins were identified as candidate key genes for adaptation to acid environments. This study suggests for the first time that exposure to cadmium strongly increases transposon expression in green algae, and that oil biosynthesis genes are induced in Chlamydomonas under heavy metal stress. Finally, the comparison of the transcriptomes of several acidophilic and non-acidophilic algae showed that the Chlamydomonas genus is polyphyletic and that acidophilic algae have distinctive aminoacid usage patterns.

In the light of a phylogenetic reconstruction based on a multi-loci data set including sequence data from all three compartments (plastome: (rps4)–trnF, rpl16 group II intron; chondrome: nad5 group I intron; nuclear: ITS1&2) the Orthostichellaceae are described as a new family of pleurocarpous mosses. It is distributed mainly in the Neotropics and tropical Africa, and provisionally contains the genera Dixonia (Asia, 1 species), Afrothamnium gen. nov. (Africa and Neotropics, 1 sp.), Pinnatidendron gen. nov. (Africa and Neotropics, 1 sp.), Deslooveria gen. nov. (Africa and French Guiana, 5 spp.), Scabrellifolium gen. nov. (Neotropics and Africa, 2 spp.), and Orthostichella (Neotropics and Africa, 9 spp.). In the Neckeraceae we describe Dannorrisia gen. nov. (N. America, 1 sp.), Austrothamnium gen. nov. (Australasia, 2 spp.), and Bryobuckia gen. nov. (endemic to Chile, 7 spp.). Porotrichum s.str. becomes an essentially Neotropical genus and it contains the formerly recognized genera Porotrichopsis and Porotrichodendron. Thamnobryum s.str. is distributed exclusively in the Northern Hemisphere and is largely temperate. The mainly Macaronesian Echinodiaceae becomes a family of two genera, Echinodium (3 spp.) and Pseudomalia gen. nov. (1 sp.). The morphological evolution in the Orthostichellaceae is discussed based on the phylogeny.

Transcriptomic sequencing together with bioinformatic analyses and an automated annotation process led us to identify novel phytochelatin synthase (PCS) genes from two extremophilic green algae (Chlamydomonas acidophila and Dunaliella acidophila). These genes are of intermediate length compared to known PCS genes from eukaryotes and PCS-like genes from prokaryotes. A detailed phylogenetic analysis gives new insight into the complicated evolutionary history of PCS genes and provides evidence for multiple horizontal gene transfer events from bacteria to eukaryotes within the gene family. A separate subgroup containing PCS-like genes within the PCS gene family is not supported since the PCS genes are monophyletic only when the PCS-like genes are included. The presence and functionality of the novel genes in the organisms were verified by genomic sequencing and qRT-PCR. Furthermore, the novel PCS gene in Chlamydomonas acidophila showed very strong induction by cadmium. Cloning and expression of the gene in Escherichia coli clearly improves its cadmium resistance. The gene in Dunaliella was not induced, most likely due to gene duplication.

The analysis of fine-scale spatial genetic structure (FSGS) within populations can provide insights into eco-evolutionary processes. Restricted dispersal and locally occurring genetic drift are the primary causes for FSGS at equilibrium, as described in the isolation by distance (IBD) model. Beyond IBD expectations, spatial, environmental or historical factors can affect FSGS. We examined FSGS in seven African and Neotropical populations of the late-successional rain forest tree Symphonia globulifera L. f. (Clusiaceae) to discriminate the influence of drift-dispersal vs. landscape/ecological features and historical processes on FSGS. We used spatial principal component analysis and Bayesian clustering to assess spatial genetic heterogeneity at SSRs and examined its association with plastid DNA and habitat features. African populations (from Cameroon and São Tomé) displayed a stronger FSGS than Neotropical populations at both marker types (mean Sp = 0.025 vs. Sp = 0.008 at SSRs) and had a stronger spatial genetic heterogeneity. All three African populations occurred in pronounced altitudinal gradients, possibly restricting animal-mediated seed dispersal. Cyto-nuclear disequilibria in Cameroonian populations also suggested a legacy of biogeographic history to explain these genetic patterns. Conversely, Neotropical populations exhibited a weaker FSGS, which may reflect more efficient wide-ranging seed dispersal by Neotropical bats and other dispersers. The population from French Guiana displayed an association of plastid haplotypes with two morphotypes characterized by differential habitat preferences. Our results highlight the importance of the microenvironment for eco-evolutionary processes within persistent tropical tree populations., SCOPUS: ar.j, info:eu-repo/semantics/published

Expressed sequence tag (EST) libraries were generated from two populations of the red alga Furcellaria lumbricalis (Hudson) Lamouroux originating from different environmental conditions (the Atlantic Ocean and the brackish Baltic Sea), compared with each other and used to guide the design of single nucleotide polymorphism (SNP) markers. The species is endemic to the northern Atlantic, while in the low-salinity conditions of the Baltic Sea it occurs at the margin of its distribution and is presently threatened by eutrophication. Primers were developed for 13 transcribed regions, five of which were found to be variable at population level, containing a total of 20 SNP sites, which were then utilized in population genetic analyses on F. lumbricalis originating from different geographical locations and salinity conditions in northern and western Europe, and the results were compared with previous data of putatively neutral and adaptive (EST-derived) microsatellites. Although no conclusive evidence of selection was detected in neutrality tests, the level of genetic differentiation based on SNP variation (FST = 0.522; but 0.398 and 0.095 for EST-derived and putatively neutral microsatellites, respectively) is so great that the role of selection is evident. The Bayesian structure analysis supported the view of great differentiation between marine and brackish populations. Although the new primers were designed for F. lumbricalis, the same gene regions may have utility in population genetic and phylogenetic studies across red algal species. Copyright © 2013 John Wiley & Sons, Ltd.

National audience

The pleurocarpous moss genus Forsstroemia (Neckeraceae) that was taxonomically revised in 1987 on morphological grounds is now revisited using sequence data from two plastid regions (rps4-trnF and rpl16) and nuclear ribosomal DNA (ITS1 and 2). The taxon sampling comprises 11 out of 13 species and a representative set of Neckeraceae and Lembophyllaceae taxa as outgroups. Forsstroemia japonica was placed next to Shevockia inunctocarpa in a clade only remotely related to Forsstroemia. Thus, F. japonica is transferred to Shevockia. Forsstroemia remotifolia is renamed as Leptodon remotifolius and Pseudopterobryum tenuicuspis as Forsstroemia tenuicuspis (syn. F. tripinnata). The nine species in Forsstroemia form a monophyletic group, six of the species being restricted to Asia, one (F. coronata) to South America, and two (F. producta and F. trichomitria) having a wider distribution. A previously suggested hybrid origin for F. coronata was not supported by the sequence data.

The Hypnales are the largest order of mosses comprising approximately 4200 species. Phylogenetic reconstruction within the group has proven to be difficult due to rapid radiation at an early stage of evolution and, consequently, relationships among clades have remained poorly resolved. We compiled data from four sequence regions, namely, nuclear ITS1–5.8S–ITS2, plastid trnL–F and rps4, and mitochondrial nad5, for 122 hypnalean species and 34 species from closely related groups. Tree topologies from both Bayesian and parsimony analyses resolve the order as monophyletic. Although inferences were made from fastevolving genes, and despite strong phylogenetic signal in the nuclear ITS1–5.8S–ITS2 data, monophyly, as well as backbone nodes within the Hypnales, remains rather poorly supported except under Bayesian inferences. Ancestral distribution based on Bayesian dispersal-vicariance analysis supports a Gondwanan origin of the Hypnales and subsequent geographical radiation in the area of the former Laurasian supercontinent. Reconstruction of historical biogeography is congruent with mainly tropical and Gondwanan distributions in the sister groups Hypnodendrales, Ptychomniales, and Hookeriales, and with the dating for the oldest pleurocarp and hypnalean fossils. We contrast groupings in the phylogenetic tree with recent classifications and other phylogenetic inferences based on molecular data, and summarise current knowledge on the evolutionary history of, and relationships among, the Hypnales.

Furcellaria lumbricalis is a red algae occurring in low salinity to fully marine conditions. Here, both putatively neutral and EST-derived microsatellite markers were developed and used to examine the genetic structure of northern European populations inhabiting different salinity conditions ranging from 35 to 3.6 psu. The amount of genetic variation did not differ between ocean and brackish populations, but differences were observed between marker types; EST-derived markers possessed less variation and showed greater differentiation than the putatively neutral microsatellites. No multicopy multilocus genotypes were detected despite expected asexuality in brackish populations. The Bayesian STRUCTURE analysis, when conducted for expressed marker data, indicated the presence of two main clusters, the Atlantic Ocean and Baltic Sea, while no clear structuring was observed based on putatively neutral microsatellites. The moderate level of genetic differentiation at neutral loci is probably due to genetic drift, a feasible explanation considering long distances between many populations, while the high level of differentiation in EST-linked markers reflects selection pressures.

In order to identify candidate genes with potential involvement in the salinity tolerance and other stress responses in the red alga Furcellaria lumbricalis (Hudson) Lamouroux, and to generate new markers for population genetic and stress tolerance adaptation studies, we constructed EST libraries from algal material originating from the marine environment of the Atlantic Ocean (35 psu), subjected to highly stressful low salinity conditions (6 psu). The obtained sequences were compared with EST sequence data originating from algal material growing naturally at 6 psu salinity in the northern Baltic Sea. The EST libraries composed of the Atlantic Ocean and Baltic Sea algal cDNA sequences consisted of 4971 and 4466 contigs, respectively. Of the contigs present in the Atlantic Ocean and Baltic Sea EST libraries, 60.5% and 56.0%, respectively, were present only within one library, while the rest, a total of 1963 contigs, were shared by the two EST libraries. The mean GC content of the EST sequences was 46.9%. The sequence searches resulted in 1612 hits in the Atlantic Ocean dataset and in 1582 hits in the Baltic Sea dataset. The majority of the gene regions remained unannotated, as gene ontology could be allocated only to altogether 576 sequences (11.6%) representing 393 different sequence regions in the Atlantic Ocean dataset, and 582 sequences (13.0%) representing 404 regions in the Baltic Sea dataset. Putatively, 28% of annotated ESTs (26% and 30% in the Atlantic Ocean and Baltic Sea, respectively) had a role in general or specific abiotic stress responses, while 4.3% of annotated ESTs were similar to genes that are known to play roles in specific salinity stress responses (4.9% and 3.8% in the Atlantic Ocean and Baltic Sea samples, respectively). Some differences between the two datasets were observed in the proportions of ESTs representing different functional categories indicating moderate functional divergence between the ocean and brackish water populations of F. lumbricalis.

Phylogenetic analyses using two fast evolving plastid markers (rps4, trnL-F) reveal the occurrence of the Australasiatic liverwort genus Lobatiriccardia in the Neotropics. Two new species, Lobatiriccardia oberwinkleri and L. verdoornioides are reported from Ecuador. Phylogenetic reconstructions support Lobatiriccardia and Aneura as monophyletic sister groups and do not place verdoornia as the first branching Aneuracean taxon but rather sister to Aneura and Lobatiriccardia, which is consistent with mycothallus development in Aneuraceae. Subsequently, Aneuraceae, as treated here, include Aneura, Lobatiriccardia, Riccardia, and Verdoornia. Although high levels of genetic structure can be observed among members of the Aneura pinguis complex, current species delimitations are questionable, and detailed analyses of cryptic speciation and biogeographic patterns are needed to understand the evolution of Aneura, with particular attention paid to the non-photosynthetic species Aneura mirabilis. Ancestral state reconstructions suggest an evolutionary trend of female gametangia, and subsequently the sporophyte, moving from a central position on the dorsal side of the thallus (Verdoornia) to a marginal position between thallus lobes (Lobatiriccardia) to a more ventral (quasi latero-ventral) position under the thallus margin (Aneura).

Leptodon corsicus (Neckeraceae) is described as the first endemic moss species from Corsica. It strikingly differs from the other species of the genus by the lack of a dense and pinnate to bipinnate mode of branching; about 10 times smaller shoots that do not inroll upon drying; the lack of paraphyllia; and few, occasional small pseudoparaphyllia. Due to its small size and several leaf characters, L. corsicus shares at first glance more similarities with Homalia webbiana and Neckera besseri than with Leptodon. Yet, phylogenetic analysis of chloroplast and nuclear DNA sequences unambiguously shows that L. corsicus is deeply nested within L. smithii. The numerous morphological characters that distinguish L. corsicus from L. smithii cannot be attributed to plasticity. Consequently, we interpret the phylogenetic position of L. corsicus as the result of a recent speciation process, involving mutations at one or a few coding loci or differences in gene expression, which have tremendous consequences for...

The status and relationships of two British narrow endemic Thamnobryum species (T. angustifolium and T. cataractarum) as well as two Macaronesian endemics (T. fernandesii and T. rudolphianum) were investigated using nuclear (ITS1&2) and plastid (the rps4-trnT-trnL-trnF cluster) markers. Geographic structure present within a monophyletic T. alopecurum containing these narrow endemic taxa, indicates that these submerged multistratose leaved forms in Britain and Madeira have been independently derived from the surrounding T. alopecurum populations and show convergent evolution in response to the extreme rheophilous habitat.

Population genetic studies in tropical plants are often challenging because of limited information on taxonomy, phylogenetic relationships and distribution ranges, scarce genomic information and logistic challenges in sampling. We describe a strategy to develop robust and widely applicable genetic markers based on a modest development of genomic resources in the ancient tropical tree species Symphonia globulifera L.f. (Clusiaceae), a keystone species in African and Neotropical rainforests. We provide the first low-coverage (11X) fragmented draft genome sequenced on an individual from Cameroon, covering 1.027 Gbp or 67.5% of the estimated genome size. Annotation of 565 scaffolds (7.57 Mbp) resulted in the prediction of 1046 putative genes (231 of them containing a complete open reading frame) and 1523 exact simple sequence repeats (SSRs, microsatellites). Aligning a published transcriptome of a French Guiana population against this draft genome produced 923 high-quality single nucleotide polymorphisms. We also preselected genic SSRs in silico that were conserved and polymorphic across a wide geographical range, thus reducing marker development tests on rare DNA samples. Of 23 SSRs tested, 19 amplified and 18 were successfully genotyped in four S. globulifera populations from South America (Brazil and French Guiana) and Africa (Cameroon and São Tomé island, FST = 0.34). Most loci showed only population-specific deviations from Hardy–Weinberg proportions, pointing to local population effects (e.g. null alleles). The described genomic resources are valuable for evolutionary studies in Symphonia and for comparative studies in plants. The methods are especially interesting for widespread tropical or endangered taxa with limited DNA availability. © 2016 John Wiley & Sons Ltd

Heavy metals are toxic compounds known to cause multiple and severe cellular damage. However, acidophilic extremophiles are able to cope with very high concentrations of heavy metals. This study investigated the stress response under natural environmental heavy metal concentrations in an acidophilic Dunaliella acidophila. We employed Illumina sequencing for a de novo transcriptome assembly and to identify changes in response to high cadmium concentrations and natural metal-rich water. The photosynthetic performance was also estimated by pulse amplitude-modulated (PAM) fluorescence. Transcriptomic analysis highlights a number of processes mainly related to a high constitutive expression of genes involved in oxidative stress and response to reactive oxygen species (ROS), even in the absence of heavy metals. Photosynthetic activity seems to be unaltered under short-term exposition to Cd and chronic exposure to natural metal-rich water, probably due to an increase in the synthesis of structural photosynthetic components preserving their functional integrity. An overrepresentation of Gene Ontology (GO) terms related to metabolic activities, transcription, and proteosomal catabolic process was observed when D. acidophila grew under chronic exposure to natural metal-rich water. GO terms involved in carbohydrate metabolic process, reticulum endoplasmic and Golgi bodies, were also specifically overrepresented in natural metal-rich water library suggesting an endoplasmic reticulum stress response. © 2016, Springer Science+Business Media New York.

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The daily photosynthetic performance of a natural biofilm of the extreme acidophilic Euglena mutabilis from Rio Tinto (SW, Spain) under full solar radiation was analyzed by means of pulse amplitude-modulated (PAM) fluorescence measurements and metatrascriptomic analysis. Natural E. mutabilis biofilms undergo large-scale transcriptomic reprogramming during midday due to a dynamic photoinhibition and solar radiation stress. Photoinhibition is due to UV radiation and not to light intensity, as revealed by PAM fluorometry analysis. In order to minimize the negative effects of solar radiation, our data supports the presence of a circadian rhythm in this euglenophyte that increases their opportunity to survive. Differential gene expression throughout the day (at 12:00, 20:00 and night) was monitored by massive Illumina parallel sequencing of metatranscriptomic libraries. The transcription pattern was altered in genes involved in Photosystem II stability and repair, UV damaged DNA repair, non-photochemical quenching and oxidative stress, supporting the photoinhibition detected by PAM fluorometry at midday.

Two closely related tropical genera from the pleurocarpous moss family Neckeraceae are revised: the second largest genus in the family, Neckeropsis , currently with 29 species, and Himantocladium , comprising six species. Twenty-one species of Neckeropsis and five of Himantocladium were included in this study, which is based on phylogenetic analyses using sequence level data from the plastid ( rps4 ) -trnT-trnL-trnF cluster and rpl16 as well as nuclear ITS1 & 2. Neckeropsis appeared as polyphyletic. Neckeropsis s. str. comprises 12 species and a further four species, not included in the analysis, are tentatively retained in the genus based on morphology. Four new genera are segregated from Neckeropsis : Pengchengwua (with one sp.), Planicladium (two spp.), Pseudoparaphysanthus (five spp.), and Neckeromnion (five spp.). Neckeropsis gracilis is synonymized with Neckeromnion urocladum and reported for the first time from Laos. Four molecular analyzed species are resolved in the Himantocladium s. str. clade, with a fifth species being added solely on morphological basis. Himantocladium formosicum is transferred to Neckeropsis . Leaf-like paraphyses (ramenta), unique in Neckeropsis s. str. , have evolved two times. In addition, the rare Noguchiodendron sphaerocarpum from the Himalayan region, the single species in its genus, was included in a phylogenetic analysis for the first time and it was found to be closely related to the Asian genus Taiwanobryum .

Adaptive evolution has often been proposed to explain correlations between habitats and certain phenotypes. In mosses, a high frequency of species with specialized sporophytic traits in exposed or epiphytic habitats was, already 100 years ago, suggested as due to adaptation. We tested this hypothesis by contrasting phylogenetic and morphological data from two moss families, Neckeraceae and Lembophyllaceae, both of which show parallel shifts to a specialized morphology and to exposed epiphytic or epilithic habitats. Phylogeny-based tests for correlated evolution revealed that evolution of four sporophytic traits is correlated with a habitat shift. For three of them, evolutionary rates of dual character-state changes suggest that habitat shifts appear prior to changes in morphology. This suggests that they could have evolved as adaptations to new habitats. Regarding the fourth correlated trait the specialized morphology had already evolved before the habitat shift. In addition, several other specialized “epiphytic” traits show no correlation with a habitat shift. Besides adaptive diversification, other processes thus also affect the match between phenotype and environment. Several potential factors such as complex genetic and developmental pathways yielding the same phenotypes, differences in strength of selection, or constraints in phenotypic evolution may lead to an inability of phylogeny-based comparative methods to detect potential adaptations.

In this study we reconstruct the structural evolution of the hyper-variable P6b region of the group I trnLeu intron in a monophyletic group of lichen-symbiotic Nostoc strains and establish it as a useful marker in the phylogenetic analysis of these organisms. The studied cyanobacteria occur as photosynthetic and/or nitrogen-fixing symbionts in lichen species of the diverse Nephroma guild. Phylogenetic analyses and secondary structure reconstructions are used to improve the understanding of the replication mechanisms in the P6b stem–loop and to explain the observed distribution patterns of indels. The variants of the P6b region in the Nostoc clade studied consist of different combinations of five sequence modules. The distribution of indels together with the ancestral character reconstruction performed enables the interpretation of the evolution of each sequence module. Our results indicate that the indel events are usually associated with single nucleotide changes in the P6b region and have occurred several times independently. In spite of their homoplasy, they provide phylogenetic information for closely related taxa. Thus we recognize that features of the P6b region can be used as molecular markers for species identification and phylogenetic studies involving symbiotic Nostoc cyanobacteria.

The family Neckeraceae is composed of three distinct clades, of which two, i.e. the Neckera and Thamnobryum clades, are well defined. The third clade, consisting of species belonging to Caduciella, Curvicladium, Handeliobryum, Himantocladium, Homaliodendron, Hydrocryphaea, Neckera, Neckeropsis, Pinnatella, Shevockia and Taiwanobryum, is the focus of this study. Based on sequence data from the trnS-rps4-trnT-trnL-trnF plastid cluster and the rpl16 intron as well as from nuclear ITS1&2, the phylogenetic relationships of these genera are reconstructed. The nearest relatives of this clade are resolved shedding more light on the evolution of the family. The generic composition of the clade and its individual genera are discussed; polyphyly requires redefinition of Pinnatella, Neckeropsis and Homaliodendron. The positions of Touwia and Homalia within the family are addressed in an additional analysis based on more extensive sequence data, and the corresponding new combinations are made. Several further taxonomic changes are proposed, including Circulifolium gen. nov., comprising the former Homaliodendron exiguum and H. microdendron.

Earlier phylogenetic studies, including species belonging to the Neckeraceae, have indicated that this pleurocarpous moss family shares a strongly supported sister group relationship with the Lembophyllaceae, but the family delimitation of the former needs adjustment. To test the monophyly of the Neckeraceae, as well as to redefine the family circumscription and to pinpoint its phylogenetic position in a larger context, a phylogenetic study based on molecular data was carried out. Sequence data were compiled, combining data from all three genomes: nuclear ITS1 and 2, plastid trnS-rps4-trnT-trnL-trnF and rpl16, and mitochondrial nad5 intron. The Neckeraceae have sometimes been divided into the two families, Neckeraceae and Thamnobryaceae, a division rejected here. Both parsimony and Bayesian analyses of molecular data revealed that the family concept of the Neckeraceae needs several further adjustments, such as the exclusion of some individual species and smaller genera as well as the inclusion of the Leptodontaceae. Within the family three well-supported clades (A, B and C) can be distinguished. Members of clade A are mainly non-Asiatic and nontropical. Most species have a weak costa and immersed capsules with reduced peristomes (mainly Neckera spp.) and the teeth at the leaf margins are usually unicellular. Clade B members are also mainly non-Asiatic. They are typically fairly robust, distinctly stipilate, having a single, at least relatively strong costa, long setae (capsules exserted), and the peristomes are well developed or only somewhat reduced. Members of clade C are essentially Asiatic and tropical. The species of this clade usually have a strong costa and a long seta, the seta often being mammillose in its upper part. The peristome types in this clade are mixed, since both reduced and unreduced types are found. Several neckeraceous genera that were recognised on a morphological basis are polyphyletic (e.g. Neckera, Homalia, Thamnobryum, Porotrichum). Ancestral state reconstructions revealed that currently used diagnostic traits, such as the leaf asymmetry and costa strength are highly homoplastic. Similarly, the reconstructions revealed that the 'reduced' sporophyte features have evolved independently in each of the three clades. Earlier phylogenetic studies, including species belonging to the Neckeraceae, have indicated that this pleurocarpous moss family shares a strongly supported sister group relationship with the Lembophyllaceae, but the family delimitation of the former needs adjustment. To test the monophyly of the Neckeraceae, as well as to redefine the family circumscription and to pinpoint its phylogenetic position in a larger context, a phylogenetic study based on molecular data was carried out. Sequence data were compiled, combining data from all three genomes: nuclear ITS1 and 2, plastid trnS-rps4-trnT-trnL-trnF and rpl16, and mitochondrial nad5 intron. The Neckeraceae have sometimes been divided into the two families, Neckeraceae and Thamnobryaceae, a division rejected here. Both parsimony and Bayesian analyses of molecular data revealed that the family concept of the Neckeraceae needs several further adjustments, such as the exclusion of some individual species and smaller genera as well as the inclusion of the Leptodontaceae. Within the family three well-supported clades (A, B and C) can be distinguished. Members of clade A are mainly non-Asiatic and nontropical. Most species have a weak costa and immersed capsules with reduced peristomes (mainly Neckera spp.) and the teeth at the leaf margins are usually unicellular. Clade B members are also mainly non-Asiatic. They are typically fairly robust, distinctly stipilate, having a single, at least relatively strong costa, long setae (capsules exserted), and the peristomes are well developed or only somewhat reduced. Members of clade C are essentially Asiatic and tropical. The species of this clade usually have a strong costa and a long seta, the seta often being mammillose in its upper part. The peristome types in this clade are mixed, since both reduced and unreduced types are found. Several neckeraceous genera that were recognised on a morphological basis are polyphyletic (e.g. Neckera, Homalia, Thamnobryum, Porotrichum). Ancestral state reconstructions revealed that currently used diagnostic traits, such as the leaf asymmetry and costa strength are highly homoplastic. Similarly, the reconstructions revealed that the 'reduced' sporophyte features have evolved independently in each of the three clades. Earlier phylogenetic studies, including species belonging to the Neckeraceae, have indicated that this pleurocarpous moss family shares a strongly supported sister group relationship with the Lembophyllaceae, but the family delimitation of the former needs adjustment. To test the monophyly of the Neckeraceae, as well as to redefine the family circumscription and to pinpoint its phylogenetic position in a larger context, a phylogenetic study based on molecular data was carried out. Sequence data were compiled, combining data from all three genomes: nuclear ITS1 and 2, plastid trnS-rps4-trnT-trnL-trnF and rpl16, and mitochondrial nad5 intron. The Neckeraceae have sometimes been divided into the two families, Neckeraceae and Thamnobryaceae, a division rejected here. Both parsimony and Bayesian analyses of molecular data revealed that the family concept of the Neckeraceae needs several further adjustments, such as the exclusion of some individual species and smaller genera as well as the inclusion of the Leptodontaceae. Within the family three well-supported clades (A, B and C) can be distinguished. Members of clade A are mainly non-Asiatic and nontropical. Most species have a weak costa and immersed capsules with reduced peristomes (mainly Neckera spp.) and the teeth at the leaf margins are usually unicellular. Clade B members are also mainly non-Asiatic. They are typically fairly robust, distinctly stipilate, having a single, at least relatively strong costa, long setae (capsules exserted), and the peristomes are well developed or only somewhat reduced. Members of clade C are essentially Asiatic and tropical. The species of this clade usually have a strong costa and a long seta, the seta often being mammillose in its upper part. The peristome types in this clade are mixed, since both reduced and unreduced types are found. Several neckeraceous genera that were recognised on a morphological basis are polyphyletic (e.g. Neckera, Homalia, Thamnobryum, Porotrichum). Ancestral state reconstructions revealed that currently used diagnostic traits, such as the leaf asymmetry and costa strength are highly homoplastic. Similarly, the reconstructions revealed that the 'reduced' sporophyte features have evolved independently in each of the three clades.

Phylogenetic analyses of the Hypnales usually show the same picture of poorly resolved trees with a large number of polyphyletic taxa and low support for the few reconstructed clades. One odd clade, however, consisting of three genera that are currently treated either within the Leskeaceae (Miyabea) or Neckeraceae (Homaliadelphus and Bissetia), was retrieved in a previously published phylogeny based on chloroplast rbcL. In order to elucidate the reliability of the observed Homaliadelphus - Miyabea - Bissetia - clade (HMB-clade) and to reveal its phylogenetic relationships a molecular study based on a representative set of hypnalean taxa was performed. Sequence data from all three genomes, namely the ITS1 and 2 (nuclear), the trnS-rps4-trnT-trnL-trnF cluster (plastid), the nad5 intron (mitochondrial), were analyzed. Although the phylogenetic reconstruction of the combined data set was not fully resolved regarding the backbone it clearly indicated the polyphyletic nature of various hypnalean families, such as the Leskeaceae, Hypnaceae, Hylocomiaceae, Neckeraceae, Leptodontaceae and Anomodontaceae with respect to the included taxa. In addition the results favor the inclusion of the Leptodontaceae and Thamnobryaceae in the Neckeraceae. The maximally supported HMB-clade consisting of the three genera Homaliadelphus (2-3 species), Miyabea (3 species) and Bissetia (1 species) is resolved sister to a so far unnamed clade comprising Taxiphyllum aomoriense, Glossadelphus ogatae and Leptopterigynandrum. The well-resolved and supported HMB-clade, here formally described as the Miyabeaceae, fam. nov. is additionally supported by morphological characters such as strongly incrassate, porose leaf cells, a relatively weak and diffuse costa and the presence of dwarf males. The latter are absent in the Neckeraceae and the Leskeaceae. It is essentially an East Asian family, with one species occurring in North America. Phylogenetic analyses of the Hypnales usually show the same picture of poorly resolved trees with a large number of polyphyletic taxa and low support for the few reconstructed clades. One odd clade, however, consisting of three genera that are currently treated either within the Leskeaceae (Miyabea) or Neckeraceae (Homaliadelphus and Bissetia), was retrieved in a previously published phylogeny based on chloroplast rbcL. In order to elucidate the reliability of the observed Homaliadelphus - Miyabea - Bissetia - clade (HMB-clade) and to reveal its phylogenetic relationships a molecular study based on a representative set of hypnalean taxa was performed. Sequence data from all three genomes, namely the ITS1 and 2 (nuclear), the trnS-rps4-trnT-trnL-trnF cluster (plastid), the nad5 intron (mitochondrial), were analyzed. Although the phylogenetic reconstruction of the combined data set was not fully resolved regarding the backbone it clearly indicated the polyphyletic nature of various hypnalean families, such as the Leskeaceae, Hypnaceae, Hylocomiaceae, Neckeraceae, Leptodontaceae and Anomodontaceae with respect to the included taxa. In addition the results favor the inclusion of the Leptodontaceae and Thamnobryaceae in the Neckeraceae. The maximally supported HMB-clade consisting of the three genera Homaliadelphus (2-3 species), Miyabea (3 species) and Bissetia (1 species) is resolved sister to a so far unnamed clade comprising Taxiphyllum aomoriense, Glossadelphus ogatae and Leptopterigynandrum. The well-resolved and supported HMB-clade, here formally described as the Miyabeaceae, fam. nov. is additionally supported by morphological characters such as strongly incrassate, porose leaf cells, a relatively weak and diffuse costa and the presence of dwarf males. The latter are absent in the Neckeraceae and the Leskeaceae. It is essentially an East Asian family, with one species occurring in North America. Phylogenetic analyses of the Hypnales usually show the same picture of poorly resolved trees with a large number of polyphyletic taxa and low support for the few reconstructed clades. One odd clade, however, consisting of three genera that are currently treated either within the Leskeaceae (Miyabea) or Neckeraceae (Homaliadelphus and Bissetia), was retrieved in a previously published phylogeny based on chloroplast rbcL. In order to elucidate the reliability of the observed Homaliadelphus - Miyabea - Bissetia - clade (HMB-clade) and to reveal its phylogenetic relationships a molecular study based on a representative set of hypnalean taxa was performed. Sequence data from all three genomes, namely the ITS1 and 2 (nuclear), the trnS-rps4-trnT-trnL-trnF cluster (plastid), the nad5 intron (mitochondrial), were analyzed. Although the phylogenetic reconstruction of the combined data set was not fully resolved regarding the backbone it clearly indicated the polyphyletic nature of various hypnalean families, such as the Leskeaceae, Hypnaceae, Hylocomiaceae, Neckeraceae, Leptodontaceae and Anomodontaceae with respect to the included taxa. In addition the results favor the inclusion of the Leptodontaceae and Thamnobryaceae in the Neckeraceae. The maximally supported HMB-clade consisting of the three genera Homaliadelphus (2-3 species), Miyabea (3 species) and Bissetia (1 species) is resolved sister to a so far unnamed clade comprising Taxiphyllum aomoriense, Glossadelphus ogatae and Leptopterigynandrum. The well-resolved and supported HMB-clade, here formally described as the Miyabeaceae, fam. nov. is additionally supported by morphological characters such as strongly incrassate, porose leaf cells, a relatively weak and diffuse costa and the presence of dwarf males. The latter are absent in the Neckeraceae and the Leskeaceae. It is essentially an East Asian family, with one species occurring in North America.

Pinnatella gollanii Broth., previously known only from north Indian collections dating back to 1903, was rediscovered in Nepal in 2001.

Pinnatella homaliadelphoides Enroth, S. Olsson, S. He, Shevock & D. Quandt (Neckeraceae, Bryophyta) is illustrated and described from China and India. Morphologically, it differs strongly from all known species of Pinnatella , but shares many features characteristic of Homaliadelphus Dixon & P. de la Varde (Miyabeaceae). The generic placement is therefore evaluated by molecular methods. Sequence data from the plastid rps4-trnT-trnL-trnF cluster as well as the rpl16 group II intron and the nuclear ITS1 & 2 place Pinnatella homaliadelphoides sister to P. foreauana Ther. & P. de la Varde, both sharing the same general geographical distribution range.

The previously invalidly published combination Homaliodendron fruticosum S. Olsson, Enroth & D. Quandt (Neckeraceae, Bryophyta) is here validated by citing the basionym.

Stress constantly challenges plant adaptation to the environment. Of all stress types, arsenic was a major threat during the early evolution of plants. The most prevalent chemical form of arsenic is arsenate, whose similarity to phosphate renders it easily incorporated into cells via the phosphate transporters. Here, we found that arsenate stress provokes a notable transposon burst in plants, in coordination with arsenate/phosphate transporter repression, which immediately restricts arsenate uptake. This repression was accompanied by delocalization of the phosphate transporter from the plasma membrane. When arsenate was removed, the system rapidly restored transcriptional expression and membrane localization of the transporter.We identifyWRKY6 as an arsenate-responsive transcription factor that mediates arsenate/phosphate transporter gene expression and restricts arsenate-induced transposon activation. Plants therefore have a dual WRKY-dependent signaling mechanism that modulates arsenate uptake and transposon expression, providing a coordinated strategy for arsenate tolerance and transposon gene silencing. © American Society of Plant Biologists. All rights reserved.

Pinnatella gollanii Broth., previously known only from north Indian collections dating back to 1903, was rediscovered in Nepal in 2001.