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Maike Petersen - One of the best experts on this subject based on the ideXlab platform.
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Phenolic metabolism in the hornwort Anthoceros agrestis: 4-coumarate CoA ligase and 4-hydroxybenzoate CoA ligase.
Plant cell reports, 2020Co-Authors: Julia Wohl, Maike PetersenAbstract:4-Coumarate coenzyme A ligase and 4-hydroxybenzoate coenzyme A ligase from the hornwort Anthoceros agrestis expressed in E. coli were characterized on biochemical and molecular levels and showed interesting substrate specificities. Acyl-activating enzymes are associated with the biosynthesis or degradation of various metabolic products such as lipids, amino acids, sugars, and natural compounds. In this work, cDNA sequences encoding 4-coumarate coenzyme A ligase (4CL) and 4-hydroxybenzoate coenzyme A ligase (4HBCL) were amplified from the hornwort Anthoceros agrestis. The coding sequences were expressed in E. coli and purified by Ni-chelate chromatography. The CoA ligases exhibited different substrate specificities. 4CL catalyzed the activation of 4-coumaric acid, 3-coumaric acid, 2-coumaric acid, caffeic acid, isoferulic acid, ferulic acid, and cinnamic acid but lacked activities towards sinapic acid and benzoic acids. In contrast, 4HBCL preferred 4-hydroxybenzoic acid and benzoic acid, but also accepted other benzoic acid derivatives except salicylic acid and 3-aminosalicylic acid. Furthermore, 4HBCL also activated isoferulic acid, cinnamic acid, 2-coumaric acid, 3-coumaric acid, 4-coumaric acid and caffeic acid, but lacked affinity for ferulic acid and sinapic acid. These substrate specificities could be related to the phenolic compounds identified in Anthoceros agrestis.
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Functional expression and characterization of cinnamic acid 4-hydroxylase from the hornwort Anthoceros agrestis in Physcomitrella patens
Plant Cell Reports, 2020Co-Authors: Julia Wohl, Maike PetersenAbstract:Key message Cinnamic acid 4-hydroxylase from the hornwort Anthoceros agrestis (AaC4H) was functionally expressed in the moss Physcomitrella patens and characterized at biochemical and molecular levels. Abstract Cinnamic acid 4-hydroxylase (C4H), a cytochrome P450-dependent hydroxylase, catalyzes the formation of 4-coumaric acid (=4-hydroxycinnamic acid) from trans -cinnamic acid. In the hornwort Anthoceros agrestis (Aa), this enzyme is supposed to be involved in the biosynthesis of rosmarinic acid (a caffeic acid ester of 3-(3,4-dihydroxyphenyl)lactic acid) and other related compounds. The coding sequence of AaC4H (CYP73A260) was expressed in the moss Physcomitrella patens (Pp_AaC4H ) . Protein extracts from the transformed moss showed considerably increased C4H activity driven by NADPH:cytochrome P450 reductase of the moss. Since Physcomitrella has own putative cinnamic acid 4-hydroxylases, enzyme characterization was carried out in parallel with the untransformed Physcomitrella wild type (Pp_WT). Apparent K _m-values for cinnamic acid and NADPH were determined to be at 17.3 µM and 88.0 µM for Pp_AaC4H and 25.1 µM and 92.3 µM for Pp_WT, respectively. Expression levels of AaC4H as well as two Physcomitrella patens C4H isoforms were analyzed by quantitative real-time PCR. While PpC4H_1 displayed constantly low levels of expression during the whole 21-day culture period, AaC4H and PpC4H_2 increased their expression during the first 6–8 days of the culture period and then decreased again. This work describes the biochemical in vitro characterization of a cytochrome P450-dependent enzyme, namely C4H, heterologously expressed in the haploid model plant Physcomitrella patens .
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production of rosmarinic acid and a new rosmarinic acid 3 o beta d glucoside in suspension cultures of the hornwort Anthoceros agrestis paton
Planta, 2006Co-Authors: Katharina Vogelsang, Bernd Schneider, Maike PetersenAbstract:Cell suspension cultures of the hornwort Anthoceros agrestis Paton (Anthocerotaceae) were cultivated and characterized in CB-media containing 2 and 4% sucrose. The suspension cells accumulated rosmarinic acid up to 5.1% of the cell dry weight as well as caffeoyl-4′-hydroxyphenyllactate. Moreover, a more hydrophilic compound was detected which was isolated and identified as rosmarinic acid 3′-O-β-D-glucoside, a new rosmarinic acid derivative. This new rosmarinic acid derivative was found up to 1.0% of the cell dry weight in suspension cells of A. agrestis.
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cinnamic acid 4 hydroxylase from cell cultures of the hornwort Anthoceros agrestis
Planta, 2003Co-Authors: Maike PetersenAbstract:Cinnamic acid 4-hydroxylase (EC 1.14.13.11), a cytochrome P450-dependent hydroxylase was for the first time characterized from a hornwort, Anthoceros agrestis Paton (Anthocerotaceae). In suspension cultures of A. agrestis up to 5% of the dry weight was accumulated as rosmarinic acid, a natural product commonly known from higher plants (e.g. species of the Lamiaceae and Boraginaceae). Cinnamic acid 4-hydroxylase is involved in the biosynthesis of rosmarinic acid. The participation of cytochrome P450 was demonstrated by the inhibition of hydroxylase activity by cytochrome c and the inhibition of cinnamic acid hydroxylation in a CO-containing atmosphere, which is partially released by illumination with blue light. The apparent K m values were determined to be at 60 μM and 5 μM for NADPH and cinnamic acid, respectively. A comparatively high hydroxylation activity was seen with NADH as electron donor. While the hydroxylase activity with NADPH was strongly inhibited by the competitive electron acceptor cytochrome c, the activity with NADH was less susceptible, indicating the possibility of different electron-transfer pathways.
Juan Carlos Villarreal - One of the best experts on this subject based on the ideXlab platform.
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morphology ultrastructure and phylogenetic affinities of the single island endemic Anthoceros cristatus steph ascension island
Journal of Bryology, 2017Co-Authors: Juan Carlos Villarreal, Jeffrey G Duckett, Silvia PresselAbstract:Oceanic islands, due to their geographical isolation, number, precisely defined boundaries and their geomorphological and climatic diversity, have provided enormous insights into speciation, dispersal, adaptive radiations and macroecological processes. One of the key components of these island studies is the role of single-island endemics (SIEs) as, in many instances, island biogeography models use the proportion of SIEs to infer evolutionary processes. It is, therefore, imperative to undertake critical taxonomic revisions to evaluate SIEs because changes in the number of SIEs have a key impact on downstream biogeographic analyses. We revise the special case of a putative SIE Anthoceros cristatus on Ascension Island using light and electron microscopy, as well phylogenomic tools. A. cristatus lies within the A. agrestis/A. punctatus complex but differs from the sister species A. agrestis and A. punctatus in spore morphology and gametophytic lamellae fringed with caducous marginal cells. The present confir...
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taxonomic notes on phaeoceros himalayensis with lectotypification of Anthoceros himalayensis
Phytotaxa, 2015Co-Authors: Sahut Chantanaorrapint, Phuntsho Penjor, Juan Carlos VillarrealAbstract:The hornworts are the smallest group of bryophytes, comprising 10 to 12 genera (Li et al. 2011; Villarreal & Renner 2012; Chantanaorrapint 2014) with approximately 220 species worldwide (Villarreal et al. 2010; Soderstrom et al. 2015). The status of some species is still unclear and several taxa are yet to be typified (Villarreal et al. 2015). Anthoceros himalayensis Kashyap (1915: 8) was first described by Kashyap from India without designating any type specimen, but was probably based on material collected by himself during a field trip in Mussoorie, Western Himalayas. Furthermore, the figure that accompanies the protologue appears, judging by the shapes of the thalli and the position of the tubers, to include line drawings of two species, namely A. himalayensis and perhaps a Phymatoceros sp. Anthoceros himalayensis was later transferred to the genus Phaeoceros Proskauer (1951: 346) by Proskauer (Bapna & Vyas 1962), however, he had not examined Kashyap’s collection. Attempts to locate Kashyap’s specimens have been problematic. Asthana and Srivastava (1991) also failed to locate the specimen during the study of Indian hornworts. It became necessary to designate a lectotype. Therefore, we here designate Kashyap’s illustration, the Figure 4.4, in the original publication (Kashyap 1915: 8) as the lectotype of Phaeoceros himalayensis (Kashyap) Proskauer (1967: 61) ex Bapna & Vyas (1962: 88) (≡ Anthoceros himalayensis Kashyap). A detailed description, line drawings, and SEM photographs are provided, based on Chopra’s collection from type locality and the recent collections from Thailand.
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horizontal transfer of an adaptive chimeric photoreceptor from bryophytes to ferns
Proceedings of the National Academy of Sciences of the United States of America, 2014Co-Authors: Juan Carlos Villarreal, Steven L Kelly, Carl J Rothfels, Michael Melkonian, Eftychios Frangedakis, Markus Ruhsam, Erin M Sigel, Joshua P Der, Jarmila Pittermann, Dylan O BurgeAbstract:Ferns are well known for their shade-dwelling habits. Their ability to thrive under low-light conditions has been linked to the evolution of a novel chimeric photoreceptor—neochrome—that fuses red-sensing phytochrome and blue-sensing phototropin modules into a single gene, thereby optimizing phototropic responses. Despite being implicated in facilitating the diversification of modern ferns, the origin of neochrome has remained a mystery. We present evidence for neochrome in hornworts (a bryophyte lineage) and demonstrate that ferns acquired neochrome from hornworts via horizontal gene transfer (HGT). Fern neochromes are nested within hornwort neochromes in our large-scale phylogenetic reconstructions of phototropin and phytochrome gene families. Divergence date estimates further support the HGT hypothesis, with fern and hornwort neochromes diverging 179 Mya, long after the split between the two plant lineages (at least 400 Mya). By analyzing the draft genome of the hornwort Anthoceros punctatus, we also discovered a previously unidentified phototropin gene that likely represents the ancestral lineage of the neochrome phototropin module. Thus, a neochrome originating in hornworts was transferred horizontally to ferns, where it may have played a significant role in the diversification of modern ferns.
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the plastid genome of the hornwort nothoceros aenigmaticus dendrocerotaceae phylogenetic signal in inverted repeat expansion pseudogenization and intron gain
American Journal of Botany, 2013Co-Authors: Juan Carlos Villarreal, Laura L. Forrest, Norman J Wickett, Bernard GoffinetAbstract: Premise of the study: The previously sequenced plastome of the hornwort Anthoceros angustus differs from that of other bryophytes by an expanded inverted repeat (IR) and the presence of a type I intron in the 23S ribosomal RNA ( rrn23 ) gene. We assembled the plastome of the hornwort Nothoceros aenigmaticus , contrasted its architecture to that of other bryophytes, and assessed the phylogenetic signifi cance of genomic characters in hornwort evolution. Methods: The Nothoceros plastome was reconstructed from shotgun sequencing of genomic DNA. Comparison with the Anthoceros plastome revealed three structural differences. We sequenced these regions in taxa spanning the hornwort phylogeny. Key results: The Nothoceros plastome is colinear with other bryophyte plastomes, but differs from the Anthoceros plastome by several gene regions located within the IR in Anthoceros being in the large single-copy region in Nothoceros , by the rrn23 gene lacking an intron, and by the rpl2 being a pseudogene. Comparisons across the hornwort phylogeny indicate that the fi rst two characters are restricted to Anthocerotaceae, while rpl2 pseudogenization diagnoses the sister lineage to Anthocerotaceae. Conclusions: The Nothoceros plastome is structurally similar to that of most bryophytes. However, we identifi ed more structural differences within hornworts than have been described within either the mosses or the liverworts. The distribution of the gene duplication involving the IR and an intron in the rrn23 gene are restricted to Anthocerotaceae. Occurrence of the intron and the conserved intron sequence between Anthoceros and distantly related chlorophyte algae may be due to horizontal gene transfer.
Christine Cargill - One of the best experts on this subject based on the ideXlab platform.
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hornworts of australia three new Anthoceros l anthocerotaceae species from new south wales
Telopea, 2021Co-Authors: Christine Cargill, Ruth PalssonAbstract:Three new species of Anthoceros sect. Fusiformes are described, all occurring on the North West Slopes and Plains of New South Wales and all sharing spore characteristics of a smooth unornamented strip either side of the triradiate mark on the proximal face. Illustrations and a distribution map are provided for all species, along with a key to Australian Anthocerotaceae.
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Notes on Early Land Plants Today. 23. A new synonym in Anthoceros (Anthocerotaceae, Anthocerotophyta)
2013Co-Authors: Christine Cargill, Lars Söderström, Anders Hagborg, Matt Von KonratAbstract:BM, HBG, L, MEL, PC, and W were searched in an attempt to find original material of these taxa. Two packets were found at G in the Stephani herbarium, one bearing the name Anthoceros fragilis (barcode G-61292) and the other lablled Anthoceros fertilis (barcode G-61293). Both annotations were in Stephani’s handwriting and the specimens match the descriptions in the protologue. The first author studied the G specimens and found they represent to the same taxon. Since the two names have equal priority, Anthoceros fragilis was chosen over Anthoceros fertilis, as the epithet more accurately describes the thallus, which is thinner and more delicate than that in the type species for the genus, Anthoceros punctatus Linnaeus (1753: 1139). Both specimens at G were collected by Amalie Dietrich from the Brisbane River area in Queensland. Dietrich’s herbarium is now in HBG with duplicates in many other herbaria. However, no duplicates of the Anthoceros material were found in HBG or several other herbaria with significant holdings of Dietrich specimens. Stephani based his descriptions of Anthoceros fragilis and Anthoceros fertilis on the specimens held in G, which appears to be the only extant type material for these names. They are thus regarded here as holotypes, despite an annotation by Proskauer on the specimen of Anthoceros fertilis to indicate that it was a
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nuevos registros de antocerotes anthocerotophyta rothm
2011Co-Authors: Yoira Riveraqueralta, Christine Cargill, Ex Stotler, Investigaciones BotanicasAbstract:The hornworts (Anthocerotophyta) are poorly studied in Cuba, compared to mosses and liverworts (Bryophyta and Marchantophyta). This study is based on the revision of herbarium material; literature consultation and the use of the optic and electronic microscopy of Scanning (JEOL LSM 6400 SEMs). After this study, the species: Anthoceros hispidus Steph. (Anthocerotaceae) and Phaeoceros oreganos (Aust.) Steph. (Notothyladaceae) were recognized and recorded for the first time in Cuba. Also, this study offered a characterization of them, photos and
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nuevos registros de antocerotes anthocerotophyta rothm ex stotler crand stotler en cuba new records of hornworts anthocerotophyta rothman
2011Co-Authors: Christine CargillAbstract:The hornworts (Anthocerotophyta) are poorly studied in Cuba, compared to mosses and liverworts (Bryophyta and Marchantophyta). This study is based on the revision of herbarium material; literature consultation and the use of the optic and electronic microscopy of Scanning (JEOL LSM 6400 SEMs). After this study, the species: Anthoceros hispidus Steph. (Anthocerotaceae) and Phaeoceros oreganos (Aust.) Steph. (Notothyladaceae) were recognized and recorded for the first time in Cuba. Also, this study offered a characterization of them, photos and
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nuevos registros de antocerotes anthocerotophyta rothm ex stotler crand stotler en cuba new records of hornworts anthocerotophyta rothman stotlar crand ex stotlar in cuba
Ciencia en su PC, 2011Co-Authors: Yoira Riveraqueralta, Christine CargillAbstract:Los antocerotes (Anthocerotophyta) son un grupo poco estudiado en Cuba, si se compara con el nivel de conocimiento que se tiene de los musgos y las hepaticas (Bryophyta y Marchantophyta). En el presente estudio, a partir de la revision de material de herbario, la consulta de literatura especializada y el empleo de la microscopia optica y electronica de barrido (JEOL LSM 6400 SEMs) se registran y se reconocen por primera vez en Cuba las especies Anthoceros hispidus Steph. (Anthocerotaceae) y Phaeoceros oreganus (Aust.) Steph. (Notothyladaceae); ademas, se ofrece su caracterizacion, fotos y fotomicrografias de las esporas. Se mapifica su distribucion y se ofrecen datos sobre la autecologia de las especies, asi como propuestas para la conservacion de las especies estudiadas. ABSTRACT The hornworts (Anthocerotophyta) are poorly studied in Cuba, compared to mosses and liverworts (Bryophyta and Marchantophyta). This study is based on the revision of herbarium material; literature consultation and the use of the optic and electronic microscopy of Scanning (JEOL LSM 6400 SEMs). After this study, the species: Anthoceros hispidus Steph. (Anthocerotaceae) and Phaeoceros oreganos (Aust.) Steph. (Notothyladaceae) were recognized and recorded for the first time in Cuba. Also, this study offered a characterization of them, photos and spores photomicrographs. Distribution maps are shown and the data on autecology species are offered; as well as proposals for the conservation of the species studied.
Péter Szövényi - One of the best experts on this subject based on the ideXlab platform.
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an agrobacterium mediated stable transformation technique for the hornwort model Anthoceros agrestis
New Phytologist, 2021Co-Authors: Eftychios Frangedakis, Manuel Waller, Tomoaki Nishiyama, Hirokazu Tsukaya, Yuling Yue, Michelle Tjahjadi, Andika Gunadi, Joyce Van Eck, Péter SzövényiAbstract:Despite their key phylogenetic position and their unique biology, hornworts have been widely overlooked. Until recently there was no hornwort model species amenable to systematic experimental investigation. Anthoceros agrestis has been proposed as the model species to study hornwort biology. We have developed an Agrobacterium-mediated method for the stable transformation of A. agrestis, a hornwort model species for which a genetic manipulation technique was not yet available. High transformation efficiency was achieved by using thallus tissue grown under low light conditions. We generated a total of 274 transgenic A. agrestis lines expressing the β-glucuronidase (GUS), cyan, green, and yellow fluorescent proteins under control of the CaMV 35S promoter and several endogenous promoters. Nuclear and plasma membrane localization with multiple color fluorescent proteins was also confirmed. The transformation technique described here should pave the way for detailed molecular and genetic studies of hornwort biology, providing much needed insight into the molecular mechanisms underlying symbiosis, carbon-concentrating mechanism, RNA editing and land plant evolution in general.
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a simple agrobacterium mediated stable transformation technique for the hornwort model Anthoceros agrestis
bioRxiv, 2021Co-Authors: Eftychios Frangedakis, Manuel Waller, Tomoaki Nishiyama, Hirokazu Tsukaya, Yuling Yue, Michelle Tjahjadi, Andika Gunadi, Joyce Van Eck, Péter SzövényiAbstract:We have developed a simple Agrobacterium-mediated method for the stable transformation of the hornwort Anthoceros agrestis, the fifth bryophyte species for which a genetic manipulation technique becomes available. High transformation efficiency was achieved by using thallus tissue grown under low-light conditions. We generated a total of 216 transgenic A. agrestis lines expressing the β-Glucuronidase (GUS), cyan, green, and yellow fluorescent proteins under the control of the CaMV 35S promoter and several endogenous promoters. Nuclear and plasma membrane localization with multiple color fluorescent proteins was also confirmed. The transformation technique described here should pave the way for detailed molecular and genetic studies of hornwort biology, providing much needed insight into the molecular mechanisms underlying symbiosis, carbon-concentrating mechanism, RNA editing, and land plant evolution in general.
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Extremely low genetic diversity in the European clade of the model bryophyte Anthoceros agrestis
Plant Systematics and Evolution, 2020Co-Authors: Thomas N. Dawes, D. Christine Cargill, Dietmar Quandt, Juan Carlos Villarreal A., Péter Szövényi, Irene Bisang, Fay-wei Li, Duncan A. Hauser, Laura L. ForrestAbstract:The hornwort Anthoceros agrestis is emerging as a model system for the study of symbiotic interactions and carbon fixation processes. It is an annual species with a remarkably small and compact genome. Single accessions of the plant have been shown to be related to the cosmopolitan perennial hornwort Anthoceros punctatus . We provide the first detailed insight into the evolutionary history of the two species. Due to the rather conserved nature of organellar loci, we sequenced multiple accessions in the Anthoceros agrestis – A. punctatus complex using three nuclear regions: the ribosomal spacer ITS2, and exon and intron regions from the single-copy coding genes rbc S and phytochrome. We used phylogenetic and dating analyses to uncover the relationships between these two taxa. Our analyses resolve a lineage of genetically near-uniform European A. agrestis accessions and two non-European A. agrestis lineages. In addition, the cosmopolitan species Anthoceros punctatus forms two lineages, one of mostly European accessions, and another from India. All studied European A. agrestis accessions have a single origin, radiated relatively recently (less than 1 million years ago), and are currently strictly associated with agroecosystem habitats.
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Establishment of Anthoceros agrestis as a model species for studying the biology of hornworts
BMC Plant Biology, 2015Co-Authors: Péter Szövényi, Dietmar Quandt, Eftychios Frangedakis, Mariana Ricca, Susann Wicke, Jane A LangdaleAbstract:Background Plants colonized terrestrial environments approximately 480 million years ago and have contributed significantly to the diversification of life on Earth. Phylogenetic analyses position a subset of charophyte algae as the sister group to land plants, and distinguish two land plant groups that diverged around 450 million years ago – the bryophytes and the vascular plants. Relationships between liverworts, mosses hornworts and vascular plants have proven difficult to resolve, and as such it is not clear which bryophyte lineage is the sister group to all other land plants and which is the sister to vascular plants. The lack of comparative molecular studies in representatives of all three lineages exacerbates this uncertainty. Such comparisons can be made between mosses and liverworts because representative model organisms are well established in these two bryophyte lineages. To date, however, a model hornwort species has not been available. Results Here we report the establishment of Anthoceros agrestis as a model hornwort species for laboratory experiments. Axenic culture conditions for maintenance and vegetative propagation have been determined, and treatments for the induction of sexual reproduction and sporophyte development have been established. In addition, protocols have been developed for the extraction of DNA and RNA that is of a quality suitable for molecular analyses. Analysis of haploid-derived genome sequence data of two A. agrestis isolates revealed single nucleotide polymorphisms at multiple loci, and thus these two strains are suitable starting material for classical genetic and mapping experiments. Conclusions Methods and resources have been developed to enable A. agrestis to be used as a model species for developmental, molecular, genomic, and genetic studies. This advance provides an unprecedented opportunity to investigate the biology of hornworts.
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establishment of Anthoceros agrestis as a model species for studying the biology of hornworts
BMC Plant Biology, 2015Co-Authors: Péter Szövényi, Dietmar Quandt, Eftychios Frangedakis, Mariana Ricca, Susann Wicke, Jane A LangdaleAbstract:Plants colonized terrestrial environments approximately 480 million years ago and have contributed significantly to the diversification of life on Earth. Phylogenetic analyses position a subset of charophyte algae as the sister group to land plants, and distinguish two land plant groups that diverged around 450 million years ago – the bryophytes and the vascular plants. Relationships between liverworts, mosses hornworts and vascular plants have proven difficult to resolve, and as such it is not clear which bryophyte lineage is the sister group to all other land plants and which is the sister to vascular plants. The lack of comparative molecular studies in representatives of all three lineages exacerbates this uncertainty. Such comparisons can be made between mosses and liverworts because representative model organisms are well established in these two bryophyte lineages. To date, however, a model hornwort species has not been available. Here we report the establishment of Anthoceros agrestis as a model hornwort species for laboratory experiments. Axenic culture conditions for maintenance and vegetative propagation have been determined, and treatments for the induction of sexual reproduction and sporophyte development have been established. In addition, protocols have been developed for the extraction of DNA and RNA that is of a quality suitable for molecular analyses. Analysis of haploid-derived genome sequence data of two A. agrestis isolates revealed single nucleotide polymorphisms at multiple loci, and thus these two strains are suitable starting material for classical genetic and mapping experiments. Methods and resources have been developed to enable A. agrestis to be used as a model species for developmental, molecular, genomic, and genetic studies. This advance provides an unprecedented opportunity to investigate the biology of hornworts.
Eftychios Frangedakis - One of the best experts on this subject based on the ideXlab platform.
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an agrobacterium mediated stable transformation technique for the hornwort model Anthoceros agrestis
New Phytologist, 2021Co-Authors: Eftychios Frangedakis, Manuel Waller, Tomoaki Nishiyama, Hirokazu Tsukaya, Yuling Yue, Michelle Tjahjadi, Andika Gunadi, Joyce Van Eck, Péter SzövényiAbstract:Despite their key phylogenetic position and their unique biology, hornworts have been widely overlooked. Until recently there was no hornwort model species amenable to systematic experimental investigation. Anthoceros agrestis has been proposed as the model species to study hornwort biology. We have developed an Agrobacterium-mediated method for the stable transformation of A. agrestis, a hornwort model species for which a genetic manipulation technique was not yet available. High transformation efficiency was achieved by using thallus tissue grown under low light conditions. We generated a total of 274 transgenic A. agrestis lines expressing the β-glucuronidase (GUS), cyan, green, and yellow fluorescent proteins under control of the CaMV 35S promoter and several endogenous promoters. Nuclear and plasma membrane localization with multiple color fluorescent proteins was also confirmed. The transformation technique described here should pave the way for detailed molecular and genetic studies of hornwort biology, providing much needed insight into the molecular mechanisms underlying symbiosis, carbon-concentrating mechanism, RNA editing and land plant evolution in general.
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a simple agrobacterium mediated stable transformation technique for the hornwort model Anthoceros agrestis
bioRxiv, 2021Co-Authors: Eftychios Frangedakis, Manuel Waller, Tomoaki Nishiyama, Hirokazu Tsukaya, Yuling Yue, Michelle Tjahjadi, Andika Gunadi, Joyce Van Eck, Péter SzövényiAbstract:We have developed a simple Agrobacterium-mediated method for the stable transformation of the hornwort Anthoceros agrestis, the fifth bryophyte species for which a genetic manipulation technique becomes available. High transformation efficiency was achieved by using thallus tissue grown under low-light conditions. We generated a total of 216 transgenic A. agrestis lines expressing the β-Glucuronidase (GUS), cyan, green, and yellow fluorescent proteins under the control of the CaMV 35S promoter and several endogenous promoters. Nuclear and plasma membrane localization with multiple color fluorescent proteins was also confirmed. The transformation technique described here should pave the way for detailed molecular and genetic studies of hornwort biology, providing much needed insight into the molecular mechanisms underlying symbiosis, carbon-concentrating mechanism, RNA editing, and land plant evolution in general.
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Establishment of Anthoceros agrestis as a model species for studying the biology of hornworts
BMC Plant Biology, 2015Co-Authors: Péter Szövényi, Dietmar Quandt, Eftychios Frangedakis, Mariana Ricca, Susann Wicke, Jane A LangdaleAbstract:Background Plants colonized terrestrial environments approximately 480 million years ago and have contributed significantly to the diversification of life on Earth. Phylogenetic analyses position a subset of charophyte algae as the sister group to land plants, and distinguish two land plant groups that diverged around 450 million years ago – the bryophytes and the vascular plants. Relationships between liverworts, mosses hornworts and vascular plants have proven difficult to resolve, and as such it is not clear which bryophyte lineage is the sister group to all other land plants and which is the sister to vascular plants. The lack of comparative molecular studies in representatives of all three lineages exacerbates this uncertainty. Such comparisons can be made between mosses and liverworts because representative model organisms are well established in these two bryophyte lineages. To date, however, a model hornwort species has not been available. Results Here we report the establishment of Anthoceros agrestis as a model hornwort species for laboratory experiments. Axenic culture conditions for maintenance and vegetative propagation have been determined, and treatments for the induction of sexual reproduction and sporophyte development have been established. In addition, protocols have been developed for the extraction of DNA and RNA that is of a quality suitable for molecular analyses. Analysis of haploid-derived genome sequence data of two A. agrestis isolates revealed single nucleotide polymorphisms at multiple loci, and thus these two strains are suitable starting material for classical genetic and mapping experiments. Conclusions Methods and resources have been developed to enable A. agrestis to be used as a model species for developmental, molecular, genomic, and genetic studies. This advance provides an unprecedented opportunity to investigate the biology of hornworts.
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establishment of Anthoceros agrestis as a model species for studying the biology of hornworts
BMC Plant Biology, 2015Co-Authors: Péter Szövényi, Dietmar Quandt, Eftychios Frangedakis, Mariana Ricca, Susann Wicke, Jane A LangdaleAbstract:Plants colonized terrestrial environments approximately 480 million years ago and have contributed significantly to the diversification of life on Earth. Phylogenetic analyses position a subset of charophyte algae as the sister group to land plants, and distinguish two land plant groups that diverged around 450 million years ago – the bryophytes and the vascular plants. Relationships between liverworts, mosses hornworts and vascular plants have proven difficult to resolve, and as such it is not clear which bryophyte lineage is the sister group to all other land plants and which is the sister to vascular plants. The lack of comparative molecular studies in representatives of all three lineages exacerbates this uncertainty. Such comparisons can be made between mosses and liverworts because representative model organisms are well established in these two bryophyte lineages. To date, however, a model hornwort species has not been available. Here we report the establishment of Anthoceros agrestis as a model hornwort species for laboratory experiments. Axenic culture conditions for maintenance and vegetative propagation have been determined, and treatments for the induction of sexual reproduction and sporophyte development have been established. In addition, protocols have been developed for the extraction of DNA and RNA that is of a quality suitable for molecular analyses. Analysis of haploid-derived genome sequence data of two A. agrestis isolates revealed single nucleotide polymorphisms at multiple loci, and thus these two strains are suitable starting material for classical genetic and mapping experiments. Methods and resources have been developed to enable A. agrestis to be used as a model species for developmental, molecular, genomic, and genetic studies. This advance provides an unprecedented opportunity to investigate the biology of hornworts.
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horizontal transfer of an adaptive chimeric photoreceptor from bryophytes to ferns
Proceedings of the National Academy of Sciences of the United States of America, 2014Co-Authors: Juan Carlos Villarreal, Steven L Kelly, Carl J Rothfels, Michael Melkonian, Eftychios Frangedakis, Markus Ruhsam, Erin M Sigel, Joshua P Der, Jarmila Pittermann, Dylan O BurgeAbstract:Ferns are well known for their shade-dwelling habits. Their ability to thrive under low-light conditions has been linked to the evolution of a novel chimeric photoreceptor—neochrome—that fuses red-sensing phytochrome and blue-sensing phototropin modules into a single gene, thereby optimizing phototropic responses. Despite being implicated in facilitating the diversification of modern ferns, the origin of neochrome has remained a mystery. We present evidence for neochrome in hornworts (a bryophyte lineage) and demonstrate that ferns acquired neochrome from hornworts via horizontal gene transfer (HGT). Fern neochromes are nested within hornwort neochromes in our large-scale phylogenetic reconstructions of phototropin and phytochrome gene families. Divergence date estimates further support the HGT hypothesis, with fern and hornwort neochromes diverging 179 Mya, long after the split between the two plant lineages (at least 400 Mya). By analyzing the draft genome of the hornwort Anthoceros punctatus, we also discovered a previously unidentified phototropin gene that likely represents the ancestral lineage of the neochrome phototropin module. Thus, a neochrome originating in hornworts was transferred horizontally to ferns, where it may have played a significant role in the diversification of modern ferns.