The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform
N. Rubén Cúneo - One of the best experts on this subject based on the ideXlab platform.
-
Origin of Equisetum: Evolution of horsetails (Equisetales) within the major euphyllophyte clade Sphenopsida.
American journal of botany, 2018Co-Authors: Andrés Elgorriaga, Ignacio H Escapa, Alexandru M. F. Tomescu, Gar W Rothwell, N. Rubén CúneoAbstract:PREMISE OF THE STUDY Equisetum is the sole living representative of Sphenopsida, a clade with impressive species richness, a long fossil history dating back to the Devonian, and obscure relationships with other living pteridophytes. Based on molecular data, the crown group age of Equisetum is mid-Paleogene, although fossils with possible crown synapomorphies appear in the Triassic. The most widely circulated hypothesis states that the lineage of Equisetum derives from calamitaceans, but no comprehensive phylogenetic studies support the claim. Using a combined approach, we provide a comprehensive phylogenetic analysis of Equisetales, with special emphasis on the origin of genus Equisetum. METHODS We performed parsimony phylogenetic analyses to address relationships of 43 equisetalean species (15 extant, 28 extinct) using a combination of morphological and molecular characters. KEY RESULTS We recovered Equisetaceae + Neocalamites as sister to Calamitaceae + a clade of Angaran and Gondwanan horsetails, with the four groups forming a clade that is sister to Archaeocalamitaceae. The estimated age for the Equisetum crown group is mid-Mesozoic. CONCLUSIONS Modern horsetails are not nested within calamitaceans; instead, both groups have explored independent evolutionary trajectories since the Carboniferous. Diverse fossil taxon sampling helps to shed light on the position and relationships of equisetalean lineages, of which only a tiny remnant is present within the extant flora. Understanding these relationships and early character configurations of ancient plant clades as Equisetales provide useful tests of hypotheses about overall phylogenetic relationships of euphyllophytes and foundations for future tests of molecular dates with paleontological data.
-
Developmental programmes in the evolution of Equisetum reproductive morphology: a hierarchical modularity hypothesis.
Annals of Botany, 2017Co-Authors: Alexandru M. F. Tomescu, Andrés Elgorriaga, Ignacio H Escapa, Gar W Rothwell, N. Rubén CúneoAbstract:Background The origin of the Equisetum strobilus has long been debated and the fossil record has played an important role in these discussions. The paradigm underlying these debates has been the perspective of the shoot as node–internode alternation, with sporangiophores attached at nodes. However, fossils historically excluded from these discussions (e.g. Cruciaetheca and Peltotheca) exhibit reproductive morphologies that suggest attachment of sporangiophores along internodes, challenging traditional views. This has rekindled discussions around the evolution of the Equisetum strobilus, but lack of mechanistic explanations has led discussions to a stalemate. Scope A shift of focus from the node–internode view to a perspective emphasizing the phytomer as a modular unit of the shoot, frees the debate of homology constraints on the nature of the sporangiophore and inspires a mechanism-based hypothesis for the evolution of the strobilus. The hypothesis, drawing on data from developmental anatomy, regulatory mechanisms and the fossil record, rests on two tenets: (1) the equisetalean shoot grows by combined activity of the apical meristem, laying down the phytomer pattern, and intercalary meristems responsible for internode elongation; and (2) activation of reproductive growth programmes in the intercalary meristem produces sporangiophore whorls along internodes. Conclusions Hierarchical expression of regulatory modules responsible for (1) transition to reproductive growth; (2) determinacy of apical growth; and (3) node–internode differentiation within phytomers, can explain reproductive morphologies illustrated by Cruciaetheca (module 1 only), Peltotheca (modules 1 and 2) and Equisetum (all three modules). This model has implications – testable by studies of the fossil record, phylogeny and development – for directionality in the evolution of reproductive morphology (Cruciaetheca–Peltotheca–Equisetum) and for the homology of the Equisetum stobilus. Furthermore, this model implies that sporangiophore development is independent of node–internode identity, suggesting that the sporangiophore represents the expression of an ancestral euphyllophyte developmental module that pre-dates the evolution of leaves.
O Soriţău - One of the best experts on this subject based on the ideXlab platform.
-
Equisetum arvense l extract induces antibacterial activity and modulates oxidative stress inflammation and apoptosis in endothelial vascular cells exposed to hyperosmotic stress
Oxidative Medicine and Cellular Longevity, 2018Co-Authors: A Pallag, Gabriela Adriana Filip, Diana Olteanu, Simona Clichici, Ioana Baldea, Tunde Jurca, Otilia Micle, Laura Vicas, Eleonora Marian, O SoriţăuAbstract:Background. The antimicrobial activity of the Equisetum arvense L. extract and the mechanisms involved in the in vitro effects on endothelial vascular cells exposed to hyperosmotic stress were evaluated. Methods. Antimicrobial activity was evaluated by disk diffusion method and minimum inhibitory concentration (MIC) determination, and oxidative stress, inflammation, and apoptosis, in pretreatment with Equisetum arvense L., caffeic acid, and cathechin, were quantified. Results. The results have shown that Equisetum arvense L. exhibited antibacterial effects only on pathogenic gram-positive cocci. The modulatory activity of Equisetum arvense L. on endothelial cells exposed to hypertonic medium was different and depended on the concentration used. Low concentrations of tested compounds exerted antioxidant effect and diminished the activity of caspase-8 and also increased IκB expression while in high doses, Equisetum arvense L. was prooxidant, induced apoptosis, and decreased IL-6 secretion. Conclusions. These experimental findings suggest that Equisetum arvense L. has antibacterial effects on gram-positive cocci and, administered in low dose, may be a new therapeutic approach for diseases associated with hypertonic conditions or oxidative stress and apoptosis.
-
Equisetum arvense l extract induces antibacterial activity and modulates oxidative stress inflammation and apoptosis in endothelial vascular cells exposed to hyperosmotic stress
Oxidative Medicine and Cellular Longevity, 2018Co-Authors: A Pallag, Gabriela Adriana Filip, Diana Olteanu, Simona Clichici, Ioana Baldea, Tunde Jurca, Otilia Micle, Laura Vicas, Eleonora Marian, O SoriţăuAbstract:Background. The antimicrobial activity of the Equisetum arvense L. extract and the mechanisms involved in the in vitro effects on endothelial vascular cells exposed to hyperosmotic stress were evaluated. Methods. Antimicrobial activity was evaluated by disk diffusion method and minimum inhibitory concentration (MIC) determination, and oxidative stress, inflammation, and apoptosis, in pretreatment with Equisetum arvense L., caffeic acid, and cathechin, were quantified. Results. The results have shown that Equisetum arvense L. exhibited antibacterial effects only on pathogenic gram-positive cocci. The modulatory activity of Equisetum arvense L. on endothelial cells exposed to hypertonic medium was different and depended on the concentration used. Low concentrations of tested compounds exerted antioxidant effect and diminished the activity of caspase-8 and also increased IκB expression while in high doses, Equisetum arvense L. was prooxidant, induced apoptosis, and decreased IL-6 secretion. Conclusions. These experimental findings suggest that Equisetum arvense L. has antibacterial effects on gram-positive cocci and, administered in low dose, may be a new therapeutic approach for diseases associated with hypertonic conditions or oxidative stress and apoptosis.
Andrés Elgorriaga - One of the best experts on this subject based on the ideXlab platform.
-
Origin of Equisetum: Evolution of horsetails (Equisetales) within the major euphyllophyte clade Sphenopsida.
American journal of botany, 2018Co-Authors: Andrés Elgorriaga, Ignacio H Escapa, Alexandru M. F. Tomescu, Gar W Rothwell, N. Rubén CúneoAbstract:PREMISE OF THE STUDY Equisetum is the sole living representative of Sphenopsida, a clade with impressive species richness, a long fossil history dating back to the Devonian, and obscure relationships with other living pteridophytes. Based on molecular data, the crown group age of Equisetum is mid-Paleogene, although fossils with possible crown synapomorphies appear in the Triassic. The most widely circulated hypothesis states that the lineage of Equisetum derives from calamitaceans, but no comprehensive phylogenetic studies support the claim. Using a combined approach, we provide a comprehensive phylogenetic analysis of Equisetales, with special emphasis on the origin of genus Equisetum. METHODS We performed parsimony phylogenetic analyses to address relationships of 43 equisetalean species (15 extant, 28 extinct) using a combination of morphological and molecular characters. KEY RESULTS We recovered Equisetaceae + Neocalamites as sister to Calamitaceae + a clade of Angaran and Gondwanan horsetails, with the four groups forming a clade that is sister to Archaeocalamitaceae. The estimated age for the Equisetum crown group is mid-Mesozoic. CONCLUSIONS Modern horsetails are not nested within calamitaceans; instead, both groups have explored independent evolutionary trajectories since the Carboniferous. Diverse fossil taxon sampling helps to shed light on the position and relationships of equisetalean lineages, of which only a tiny remnant is present within the extant flora. Understanding these relationships and early character configurations of ancient plant clades as Equisetales provide useful tests of hypotheses about overall phylogenetic relationships of euphyllophytes and foundations for future tests of molecular dates with paleontological data.
-
Developmental programmes in the evolution of Equisetum reproductive morphology: a hierarchical modularity hypothesis.
Annals of Botany, 2017Co-Authors: Alexandru M. F. Tomescu, Andrés Elgorriaga, Ignacio H Escapa, Gar W Rothwell, N. Rubén CúneoAbstract:Background The origin of the Equisetum strobilus has long been debated and the fossil record has played an important role in these discussions. The paradigm underlying these debates has been the perspective of the shoot as node–internode alternation, with sporangiophores attached at nodes. However, fossils historically excluded from these discussions (e.g. Cruciaetheca and Peltotheca) exhibit reproductive morphologies that suggest attachment of sporangiophores along internodes, challenging traditional views. This has rekindled discussions around the evolution of the Equisetum strobilus, but lack of mechanistic explanations has led discussions to a stalemate. Scope A shift of focus from the node–internode view to a perspective emphasizing the phytomer as a modular unit of the shoot, frees the debate of homology constraints on the nature of the sporangiophore and inspires a mechanism-based hypothesis for the evolution of the strobilus. The hypothesis, drawing on data from developmental anatomy, regulatory mechanisms and the fossil record, rests on two tenets: (1) the equisetalean shoot grows by combined activity of the apical meristem, laying down the phytomer pattern, and intercalary meristems responsible for internode elongation; and (2) activation of reproductive growth programmes in the intercalary meristem produces sporangiophore whorls along internodes. Conclusions Hierarchical expression of regulatory modules responsible for (1) transition to reproductive growth; (2) determinacy of apical growth; and (3) node–internode differentiation within phytomers, can explain reproductive morphologies illustrated by Cruciaetheca (module 1 only), Peltotheca (modules 1 and 2) and Equisetum (all three modules). This model has implications – testable by studies of the fossil record, phylogeny and development – for directionality in the evolution of reproductive morphology (Cruciaetheca–Peltotheca–Equisetum) and for the homology of the Equisetum stobilus. Furthermore, this model implies that sporangiophore development is independent of node–internode identity, suggesting that the sporangiophore represents the expression of an ancestral euphyllophyte developmental module that pre-dates the evolution of leaves.
-
Reconstruction and Phylogenetic Significance of a New Equisetum Linnaeus Species from the Lower Jurassic of Cerro Bayo (Chubut Province, Argentina)
Ameghiniana, 2015Co-Authors: Andrés Elgorriaga, Ignacio H Escapa, Benjamin Bomfleur, Rubén Cúneo, Eduardo G. OttoneAbstract:We describe Equisetum dimorphum sp. nov. from the Lower Jurassic of Chubut Province, Patagonia, Argentina. This new species is based on fertile and vegetative remains preserved as impressions of stems, leaves, strobili, transversal sections of the stems showing their anatomy, and terminal pagoda-like structures. The fine-grained sedimentary matrix also preserved detailed impressions of epidermal features. The morphological characters allow a whole-plant reconstruction and assignment to Equisetum. Equisetum dimorphum sp. nov. shows a mosaic of morphological characters that are commonly present in other Mesozoic forms and representatives of the two extant Equisetum subgenera, e.g., sunken stomata and a blunt strobilus apex. Compared to other well-known Mesozoic equisetalean taxa, Equisetum dimorphum sp. nov. appears to be most closely related to a group of Jurassic Equisetum-like plants including Equisetum laterale Phillips and Equisetites ferganensis Seward. Additional evidence for the morphological stasis of the fertile and vegetative organs of extant horsetails is supplied with this new material, adding further support to the hypothesis that the extant horsetails are a successful group that has undergone only little morphological changeover time and that has been present, nearly worldwide, since Jurassic times.
Alexandru M. F. Tomescu - One of the best experts on this subject based on the ideXlab platform.
-
Origin of Equisetum: Evolution of horsetails (Equisetales) within the major euphyllophyte clade Sphenopsida.
American journal of botany, 2018Co-Authors: Andrés Elgorriaga, Ignacio H Escapa, Alexandru M. F. Tomescu, Gar W Rothwell, N. Rubén CúneoAbstract:PREMISE OF THE STUDY Equisetum is the sole living representative of Sphenopsida, a clade with impressive species richness, a long fossil history dating back to the Devonian, and obscure relationships with other living pteridophytes. Based on molecular data, the crown group age of Equisetum is mid-Paleogene, although fossils with possible crown synapomorphies appear in the Triassic. The most widely circulated hypothesis states that the lineage of Equisetum derives from calamitaceans, but no comprehensive phylogenetic studies support the claim. Using a combined approach, we provide a comprehensive phylogenetic analysis of Equisetales, with special emphasis on the origin of genus Equisetum. METHODS We performed parsimony phylogenetic analyses to address relationships of 43 equisetalean species (15 extant, 28 extinct) using a combination of morphological and molecular characters. KEY RESULTS We recovered Equisetaceae + Neocalamites as sister to Calamitaceae + a clade of Angaran and Gondwanan horsetails, with the four groups forming a clade that is sister to Archaeocalamitaceae. The estimated age for the Equisetum crown group is mid-Mesozoic. CONCLUSIONS Modern horsetails are not nested within calamitaceans; instead, both groups have explored independent evolutionary trajectories since the Carboniferous. Diverse fossil taxon sampling helps to shed light on the position and relationships of equisetalean lineages, of which only a tiny remnant is present within the extant flora. Understanding these relationships and early character configurations of ancient plant clades as Equisetales provide useful tests of hypotheses about overall phylogenetic relationships of euphyllophytes and foundations for future tests of molecular dates with paleontological data.
-
Developmental programmes in the evolution of Equisetum reproductive morphology: a hierarchical modularity hypothesis.
Annals of Botany, 2017Co-Authors: Alexandru M. F. Tomescu, Andrés Elgorriaga, Ignacio H Escapa, Gar W Rothwell, N. Rubén CúneoAbstract:Background The origin of the Equisetum strobilus has long been debated and the fossil record has played an important role in these discussions. The paradigm underlying these debates has been the perspective of the shoot as node–internode alternation, with sporangiophores attached at nodes. However, fossils historically excluded from these discussions (e.g. Cruciaetheca and Peltotheca) exhibit reproductive morphologies that suggest attachment of sporangiophores along internodes, challenging traditional views. This has rekindled discussions around the evolution of the Equisetum strobilus, but lack of mechanistic explanations has led discussions to a stalemate. Scope A shift of focus from the node–internode view to a perspective emphasizing the phytomer as a modular unit of the shoot, frees the debate of homology constraints on the nature of the sporangiophore and inspires a mechanism-based hypothesis for the evolution of the strobilus. The hypothesis, drawing on data from developmental anatomy, regulatory mechanisms and the fossil record, rests on two tenets: (1) the equisetalean shoot grows by combined activity of the apical meristem, laying down the phytomer pattern, and intercalary meristems responsible for internode elongation; and (2) activation of reproductive growth programmes in the intercalary meristem produces sporangiophore whorls along internodes. Conclusions Hierarchical expression of regulatory modules responsible for (1) transition to reproductive growth; (2) determinacy of apical growth; and (3) node–internode differentiation within phytomers, can explain reproductive morphologies illustrated by Cruciaetheca (module 1 only), Peltotheca (modules 1 and 2) and Equisetum (all three modules). This model has implications – testable by studies of the fossil record, phylogeny and development – for directionality in the evolution of reproductive morphology (Cruciaetheca–Peltotheca–Equisetum) and for the homology of the Equisetum stobilus. Furthermore, this model implies that sporangiophore development is independent of node–internode identity, suggesting that the sporangiophore represents the expression of an ancestral euphyllophyte developmental module that pre-dates the evolution of leaves.
A Pallag - One of the best experts on this subject based on the ideXlab platform.
-
Equisetum arvense l extract induces antibacterial activity and modulates oxidative stress inflammation and apoptosis in endothelial vascular cells exposed to hyperosmotic stress
Oxidative Medicine and Cellular Longevity, 2018Co-Authors: A Pallag, Gabriela Adriana Filip, Diana Olteanu, Simona Clichici, Ioana Baldea, Tunde Jurca, Otilia Micle, Laura Vicas, Eleonora Marian, O SoriţăuAbstract:Background. The antimicrobial activity of the Equisetum arvense L. extract and the mechanisms involved in the in vitro effects on endothelial vascular cells exposed to hyperosmotic stress were evaluated. Methods. Antimicrobial activity was evaluated by disk diffusion method and minimum inhibitory concentration (MIC) determination, and oxidative stress, inflammation, and apoptosis, in pretreatment with Equisetum arvense L., caffeic acid, and cathechin, were quantified. Results. The results have shown that Equisetum arvense L. exhibited antibacterial effects only on pathogenic gram-positive cocci. The modulatory activity of Equisetum arvense L. on endothelial cells exposed to hypertonic medium was different and depended on the concentration used. Low concentrations of tested compounds exerted antioxidant effect and diminished the activity of caspase-8 and also increased IκB expression while in high doses, Equisetum arvense L. was prooxidant, induced apoptosis, and decreased IL-6 secretion. Conclusions. These experimental findings suggest that Equisetum arvense L. has antibacterial effects on gram-positive cocci and, administered in low dose, may be a new therapeutic approach for diseases associated with hypertonic conditions or oxidative stress and apoptosis.
-
Equisetum arvense l extract induces antibacterial activity and modulates oxidative stress inflammation and apoptosis in endothelial vascular cells exposed to hyperosmotic stress
Oxidative Medicine and Cellular Longevity, 2018Co-Authors: A Pallag, Gabriela Adriana Filip, Diana Olteanu, Simona Clichici, Ioana Baldea, Tunde Jurca, Otilia Micle, Laura Vicas, Eleonora Marian, O SoriţăuAbstract:Background. The antimicrobial activity of the Equisetum arvense L. extract and the mechanisms involved in the in vitro effects on endothelial vascular cells exposed to hyperosmotic stress were evaluated. Methods. Antimicrobial activity was evaluated by disk diffusion method and minimum inhibitory concentration (MIC) determination, and oxidative stress, inflammation, and apoptosis, in pretreatment with Equisetum arvense L., caffeic acid, and cathechin, were quantified. Results. The results have shown that Equisetum arvense L. exhibited antibacterial effects only on pathogenic gram-positive cocci. The modulatory activity of Equisetum arvense L. on endothelial cells exposed to hypertonic medium was different and depended on the concentration used. Low concentrations of tested compounds exerted antioxidant effect and diminished the activity of caspase-8 and also increased IκB expression while in high doses, Equisetum arvense L. was prooxidant, induced apoptosis, and decreased IL-6 secretion. Conclusions. These experimental findings suggest that Equisetum arvense L. has antibacterial effects on gram-positive cocci and, administered in low dose, may be a new therapeutic approach for diseases associated with hypertonic conditions or oxidative stress and apoptosis.