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Pesquisa : B01.650.940.800.575.156.955 [Categoria DeCS]
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[PMID]:28515078
[Au] Autor:Salas-Leiva DE; Meerow AW; Calonje M; Francisco-Ortega J; Griffith MP; Nakamura K; Sánchez V; Knowles L; Knowles D
[Ad] Endereço:International Center for Tropical Botany, Department of Biological Sciences, 11200 S.W. 8th Street, Florida International University, Miami, Florida 33199 USA.
[Ti] Título:Shifting Quaternary migration patterns in the Bahamian archipelago: Evidence from the complex at the northern limits of the Caribbean island biodiversity hotspot.
[So] Source:Am J Bot;104(5):757-771, 2017 May.
[Is] ISSN:1537-2197
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:PREMISE OF THE STUDY: The Bahamas archipelago is formed by young, tectonically stable carbonate banks that harbor direct geological evidence of global ice-volume changes. We sought to detect signatures of major changes on gene flow patterns and reconstruct the phylogeographic history of the monophyletic complex across the Bahamas. METHODS: Nuclear molecular markers with both high and low mutation rates were used to capture two different time scale signatures and test several gene flow and demographic hypotheses. KEY RESULTS: Single-copy nuclear genes unveiled apparent ancestral admixture on Andros, suggesting a significant role of this island as main hub of diversity of the archipelago. We detected demographic and spatial expansion of the complex on both paleo-provinces around the Piacenzian (Pliocene)/Gelasian (Pleistocene). Populations evidenced signatures of different migration models that have occurred at two different times. Populations on Long Island ( ) may either represent a secondary colonization of the Bahamas by or a rapid and early-divergence event of at least one population on the Bahamas. CONCLUSIONS: Despite changes in migration patterns with global climate, expected heterozygosity with both marker systems remains within the range reported for cycads, but with significant levels of increased inbreeding detected by the microsatellites. This finding is likely associated with reduced gene flow between and within paleo-provinces, accompanied by genetic drift, as rising seas enforced isolation. Our study highlights the importance of the maintenance of the predominant direction of genetic exchange and the role of overseas dispersion among the islands during climate oscillations.
[Mh] Termos MeSH primário: Biodiversidade
Filogenia
Zamiaceae/genética
[Mh] Termos MeSH secundário: Bahamas
Variação Genética
Ilhas
Repetições de Microssatélites
Filogeografia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171019
[Lr] Data última revisão:
171019
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170519
[St] Status:MEDLINE
[do] DOI:10.3732/ajb.1700054


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[PMID]:27704314
[Au] Autor:Prado A; Rubio-Mendez G; Yañez-Espinosa L; Bede JC
[Ad] Endereço:Department of Plant Science, McGill University, 21, 111 Lakeshore Road St., Anne de Bellevue, QC, Canada.
[Ti] Título:Ontogenetic Changes in Azoxyglycoside Levels in the Leaves of Dioon edule Lindl.
[So] Source:J Chem Ecol;42(11):1142-1150, 2016 Nov.
[Is] ISSN:1573-1561
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Plants have multiple strategies, including phytochemicals that protect their vulnerable tissues against pathogens and herbivores. Dioon edule, like all cycads, possess unique azoxy-type compounds, azoxyglycosides (AZGs) as a chemical defense; however, the ontogenetic variability of these compounds in this long-lived cycad is unknown. Here, we investigated the effects of plant age, sex, genotype and individual heterozygosity on AZG levels in mature leaves of wild D. edule populations from eastern Mexico. Individuals were divided into three ontogenetic stages: seedlings, juveniles and adults. We established overall leaf quality by quantifying pigments associated with photosynthesis; chlorophyll , chlorophyll and lutein. Leaf chlorophyll levels were higher in seedlings compared to adult cycads. Plants were genotyped using 11 microsatellite markers and foliar AZG levels were quantified by HPLC. AZG levels do not correlate with plant genotype or the individual's heterozygosity. Genetic analysis identified a distinction between lowland and highland individuals; foliar AZG levels were higher in lowland adult cycads compared to highland individuals. In both populations, the highest AZG levels were found in seedlings compared to adult cycads. These young cycads are highly reliant on their few leaves since seedlings bear one or two leaves for the first years of their life and, thus, are unlikely to recover from defoliation. The results suggest that cycad leaves with a greater nutritive content and a higher value for long-term survival are better protected with higher AZG levels. Female adult cycads have higher AZG levels compared to males, suggesting that the benefits of defense could also be linked to reproductive costs.
[Mh] Termos MeSH primário: Glicosídeos/metabolismo
Folhas de Planta/metabolismo
Zamiaceae/crescimento & desenvolvimento
Zamiaceae/metabolismo
[Mh] Termos MeSH secundário: Ontologias Biológicas
Heterozigoto
Pigmentos Biológicos/metabolismo
Zamiaceae/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Glycosides); 0 (Pigments, Biological)
[Em] Mês de entrada:1702
[Cu] Atualização por classe:171027
[Lr] Data última revisão:
171027
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161006
[St] Status:MEDLINE


  3 / 36 MEDLINE  
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[PMID]:26446814
[Au] Autor:Suinyuy TN; Donaldson JS; Johnson SD
[Ad] Endereço:School of Life Sciences, University of KwaZulu-Natal, P/Bag X01, Scottsville, Pietermaritzburg 3201, South Africa Kirstenbosch Research Centre, South African National Biodiversity Institute, P/Bag X7, Claremont, Cape Town 7735, South Africa Department of Biological Sciences, University of Cape Town, P/Bag Rondebosch, Cape Town 7701, South Africa tsuinyuy@gmail.com.
[Ti] Título:Geographical matching of volatile signals and pollinator olfactory responses in a cycad brood-site mutualism.
[So] Source:Proc Biol Sci;282(1816):20152053, 2015 Oct 07.
[Is] ISSN:1471-2954
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Brood-site mutualisms represent extreme levels of reciprocal specialization between plants and insect pollinators, raising questions about whether these mutualisms are mediated by volatile signals and whether these signals and insect responses to them covary geographically in a manner expected from coevolution. Cycads are an ancient plant lineage in which almost all extant species are pollinated through brood-site mutualisms with insects. We investigated whether volatile emissions and insect olfactory responses are matched across the distribution range of the African cycad Encephalartos villosus. This cycad species is pollinated by the same beetle species across its distribution, but cone volatile emissions are dominated by alkenes in northern populations, and by monoterpenes and a pyrazine compound in southern populations. In reciprocal choice experiments, insects chose the scent of cones from the local region over that of cones from the other region. Antennae of beetles from northern populations responded mainly to alkenes, while those of beetles from southern populations responded mainly to pyrazine. In bioassay experiments, beetles were most strongly attracted to alkenes in northern populations and to the pyrazine compound in southern populations. Geographical matching of cone volatiles and pollinator olfactory preference is consistent with coevolution in this specialized mutualism.
[Mh] Termos MeSH primário: Coleópteros/fisiologia
Polinização
Simbiose
Compostos Orgânicos Voláteis/metabolismo
Zamiaceae/fisiologia
[Mh] Termos MeSH secundário: Animais
Evolução Biológica
Geografia
Odorantes/análise
Percepção Olfatória
África do Sul
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Volatile Organic Compounds)
[Em] Mês de entrada:1607
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151009
[St] Status:MEDLINE


  4 / 36 MEDLINE  
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[PMID]:26220840
[Au] Autor:Brookes DR; Hereward JP; Terry LI; Walter GH
[Ad] Endereço:The University of Queensland, School of Biological Sciences, Brisbane, 4072 Queensland, Australia. Electronic address: dean.brookes@uqconnect.edu.au.
[Ti] Título:Evolutionary dynamics of a cycad obligate pollination mutualism - Pattern and process in extant Macrozamia cycads and their specialist thrips pollinators.
[So] Source:Mol Phylogenet Evol;93:83-93, 2015 Dec.
[Is] ISSN:1095-9513
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Obligate pollination mutualisms are rare and few have been investigated deeply. This paper focuses on one such mutualism involving thrips in the genus Cycadothrips that pollinate cycads in the genus Macrozamia. Both represent old lineages relative to insects and plants generally, are endemic to Australia, and are mutually co-dependent. The phylogenetic analyses presented here demonstrate that the pollinator is much more diverse than previously considered, with each pollinator lineage being extremely specific to between one and three host species where these latter share part of their distribution. The new species diversity we demonstrate in Cycadothrips all presently falls under the species name C. chadwicki, and these different lineages diversified during two periods. An older divergence, beginning 7.3Mya (4.4-11.1, 95% HPD), resulted in three major lineages, and then further diversification within each of these three lineages took place at most 1.1Mya (0.6-1.8, 95% HPD). These divergence estimates correspond to times when aridification was increasing in Australia, suggesting that population fragmentation following climatic change has played a significant role in the evolutionary history of Cycadothrips and Macrozamia. This means that co-diversification of the host and pollinator in allopatry appears to be the dominant process affecting species diversity. Host switching is also clearly evident in the discrepancy between the divergence times of the C. chadwicki lineage and C. albrechti, about 10.8Mya (6.0-17.1, 95% HPD), and their hosts, at about 1.1Mya (0.2-3.4Mya, 95% HPD), in that the pollinator split pre-dates the origin of the associated host species of each. These results add to the body of evidence that the evolutionary processes important in obligate pollinator mutualisms are more varied than previously assumed.
[Mh] Termos MeSH primário: Evolução Biológica
Polinização
Simbiose
Tisanópteros/fisiologia
Zamiaceae/fisiologia
[Mh] Termos MeSH secundário: Animais
Austrália
Fluxo Gênico
Genética Populacional
Geografia
Haplótipos/genética
Repetições de Microssatélites/genética
Filogenia
Especificidade da Espécie
Fatores de Tempo
Zamiaceae/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Em] Mês de entrada:1605
[Cu] Atualização por classe:151002
[Lr] Data última revisão:
151002
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150730
[St] Status:MEDLINE


  5 / 36 MEDLINE  
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[PMID]:26199364
[Au] Autor:Yan X; Bai M; Ning X; Ouyang H; Zhang S; Yang M; Wu H
[Ad] Endereço:State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangzhou 510642, China.
[Ti] Título:Spatiotemporal features of microsporogenesis in the cycad species Macrozamia communis.
[So] Source:Am J Bot;102(7):1061-72, 2015 Jul.
[Is] ISSN:1537-2197
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:UNLABELLED: • PREMISE OF THE STUDY: Spatiotemporal features of microsporogenesis may provide important clues about the evolution of microsporogenesis in seed plants. One cellular feature that attracts special attention is advance cell wall ingrowths (ACWIs) at future cytokinetic sites in microsporocytes since they have been found only in species of an ancient lineage of angiosperms, Magnolia, and in much less detail, of an ancient lineage of gymnosperms, cycads. Further investigation into microsporogenesis in a cycad species may yield knowledge critical to understanding the establishment of ACWIs as an important feature for comparative studies of microsporogenesis in seed plants.• METHODS: Bright-field and epifluorescence microscopy, confocal laser scanning microscopy, and transmission electron microscopy were used to investigate the microsporogenic process in Macrozamia communis, a species in the Zamiaceae family of cycads.• KEY RESULTS: In prophase-II microsporocytes in M. communis, ACWIs form as a callose ring between the newly formed nuclei and are not accompanied by cytokinetic apparatuses such as mini-phragmoplasts, wide tubules, or wide tubular networks. Shortly after the second nuclear division, new ACWIs, albeit thinner than the previous ACWIs, form between the newly formed nuclei. Subsequent cell plate formation in the planes of the ACWIs typically results in tetragonal tetrads.• CONCLUSIONS: Cytokinesis at the cell periphery is initiated earlier than cell plate formation in the cell interior in microsporogenesis in M. communis. The cellular features uncovered in M. communis may serve as useful reference features for comparative studies of microsporogenesis in plants.
[Mh] Termos MeSH primário: Citocinese
Gametogênese Vegetal
Sementes/fisiologia
Zamiaceae/fisiologia
[Mh] Termos MeSH secundário: Evolução Biológica
Parede Celular/metabolismo
Parede Celular/ultraestrutura
Células Germinativas Vegetais/fisiologia
Células Germinativas Vegetais/ultraestrutura
Glucanos/metabolismo
Sementes/ultraestrutura
Análise Espaço-Temporal
Zamiaceae/ultraestrutura
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Glucans); 9064-51-1 (callose)
[Em] Mês de entrada:1604
[Cu] Atualização por classe:150722
[Lr] Data última revisão:
150722
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150723
[St] Status:MEDLINE
[do] DOI:10.3732/ajb.1500112


  6 / 36 MEDLINE  
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[PMID]:25015529
[Au] Autor:Woodenberg WR; Pammenter NW; Farrant JM; Driouich A; Berjak P
[Ti] Título:Embryo cell wall properties in relation to development and desiccation in the recalcitrant-seeded Encephalartos natalensis (Zamiaceae) Dyer and Verdoorn.
[So] Source:Protoplasma;252(1):245-58, 2015 Jan.
[Is] ISSN:1615-6102
[Cp] País de publicação:Austria
[La] Idioma:eng
[Ab] Resumo:Plant cell walls are dynamic entities that may change with development, differ between plant species and tissue type and play an important role in responses to various stresses. In this regard, the present investigation employed immunocytochemistry to determine wall composition and possible changes during development of immature and mature embryos of the recalcitrant-seeded cycad Encephalartos natalensis. Fluorescent and gold markers, together with cryo-scanning and transmission electron microscopy (TEM) were also used to analyse potential changes in the cell walls of mature embryos upon desiccation. Immature cell walls were characterised by low- and high methyl-esterified epitopes of pectin, rhamnogalacturonan-associated arabinan, and the hemicellulose xyloglucan. Arabinogalactan protein recognised by the LM2 antibody, along with rhamnogalacturonan-associated galactan and the hemicellulose xylan, were not positively localised using immunological probes, suggesting that the cell walls of the embryo of E. natalensis do not possess these epitopes. Interestingly, mature embryos appeared to be identical to immature ones with respect to the cell wall components investigated, implying that these may not change during the protracted post-shedding embryogenesis of this species. Drying appeared to induce some degree of cell wall folding in mature embryos, although this was limited by the abundant amyloplasts, which filled the cytomatrical space. Folding, however, was correlated with relatively high levels of wall plasticisers typified by arabinose polymers. From the results of this study, it is proposed that the embryo cell walls of E. natalensis are constitutively prepared for the flexibility required during cell growth and expansion, which may also facilitate the moderate cell wall folding observed in mature embryos upon drying. This, together with the abundant occurrence of amyloplasts in the cytomatrix, may provide sufficient mechanical stabilisation if water is lost, even though the seeds of this species are highly desiccation-sensitive.
[Mh] Termos MeSH primário: Parede Celular/química
Microscopia de Fluorescência/métodos
Zamiaceae/química
[Mh] Termos MeSH secundário: Dessecação
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Em] Mês de entrada:1602
[Cu] Atualização por classe:171012
[Lr] Data última revisão:
171012
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:140713
[St] Status:MEDLINE


  7 / 36 MEDLINE  
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[PMID]:25331676
[Au] Autor:Retief K; West AG; Pfab MF
[Ad] Endereço:Department of Biological Sciences, University of Cape Town, Private Bag X1, Rondebosch, Cape Town, South Africa.
[Ti] Título:Can stable isotopes and radiocarbon dating provide a forensic solution for curbing illegal harvesting of threatened cycads?
[So] Source:J Forensic Sci;59(6):1541-51, 2014 Nov.
[Is] ISSN:1556-4029
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Cycads in South Africa are facing an extinction crisis due to the illegal extraction of plants from the wild. Proving wild origin of suspect ex situ cycads to the satisfaction of a court of law is difficult, limiting law enforcement efforts. We investigated the feasibility of using multiple stable isotopes to identify specimens removed from the wild. Relocated and wild specimens from two species in the African genus Encephalartos (E. lebomboensis and E. arenarius) were sampled. (14) C analysis indicated that a ± 30-year chronology could be reliably obtained from the cycads. For E. arenarius, pre-relocation tissue was consistent with a wild origin, whereas tissue grown post-relocation was isotopically distinct from the wild for (87) Sr/(86) Sr and δ(15) N. For E. lebomboensis, δ(34) S, δ(18) O, and (87) Sr/(86) Sr were different between relocated and control plants, consistent with the >30 years since relocation. Our findings demonstrate the potential for a forensic isotope approach to identify illegal ex situ cycads.
[Mh] Termos MeSH primário: Crime
Espécies em Perigo de Extinção
Zamiaceae/química
[Mh] Termos MeSH secundário: Botânica
Radioisótopos de Carbono/análise
Comércio
Ciências Forenses
Radioisótopos de Chumbo
Radioisótopos de Nitrogênio
Folhas de Planta/química
Análise de Componente Principal
Radioisótopos de Estrôncio
Radioisótopos de Enxofre
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Carbon Radioisotopes); 0 (Lead Radioisotopes); 0 (Nitrogen Radioisotopes); 0 (Strontium Radioisotopes); 0 (Sulfur Radioisotopes)
[Em] Mês de entrada:1601
[Cu] Atualização por classe:141110
[Lr] Data última revisão:
141110
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:141022
[St] Status:MEDLINE
[do] DOI:10.1111/1556-4029.12644


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[PMID]:25172315
[Au] Autor:Hall JA; Walter GH
[Ad] Endereço:School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia, john.hall@uq.edu.au.
[Ti] Título:Relative seed and fruit toxicity of the Australian cycads Macrozamia miquelii and Cycas ophiolitica: further evidence for a megafaunal seed dispersal syndrome in cycads, and its possible antiquity.
[So] Source:J Chem Ecol;40(8):860-8, 2014 Aug.
[Is] ISSN:1573-1561
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:An apparent contradiction in the ecology of cycad plants is that their seeds are known to be highly poisonous, and yet they seem well adapted for seed dispersal by animals, as shown by their visually conspicuous seed cones and large seeds presented within a brightly colored fleshy "fruit" of sarcotesta. We tested if this sarcotesta could function as a reward for cycad seed dispersal fauna, by establishing if the toxic compound cycasin, known from the seeds, is absent from the sarcotesta. The Australian cycads Macrozamia miquelii and Cycas ophiolitica were tested (N = 10 individuals per species) using gas chromatography / mass spectrometry. Cycasin was detected at 0.34 % (fresh weight) in seed endosperm of M. miquelii and 0.28 % (fresh weight) in seed endosperm of C. ophiolitica. Cycasin was absent from the sarcotesta of the same propagules (none detected in the case of M. miquelii, and trace quantities detected in sarcotesta of only four of the ten C. ophiolitica propagules). This laboratory finding was supported by field observations of native animals eating the sarcotesta of these cycads but discarding the toxic seed intact. These results suggest cycads are adapted for dispersal fauna capable of swallowing the large, heavy propagules whole, digesting the non-toxic sarcotesta flesh internally, and then voiding the toxic seed intact. Megafauna species such as extant emus or cassowaries, or extinct Pleistocene megafauna such as Genyornis, are plausible candidates for such dispersal. Cycads are an ancient lineage, and the possible antiquity of their megafaunal seed dispersal adaptations are discussed.
[Mh] Termos MeSH primário: Cycas/fisiologia
Cicasina/metabolismo
Extinção Biológica
Frutas/química
Dispersão de Sementes
Sementes/química
Zamiaceae/fisiologia
[Mh] Termos MeSH secundário: Animais
Austrália
Tamanho Corporal
Cycas/química
Especificidade da Espécie
Vertebrados
Zamiaceae/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
9H51HL0E1D (Cycasin)
[Em] Mês de entrada:1507
[Cu] Atualização por classe:171027
[Lr] Data última revisão:
171027
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:140831
[St] Status:MEDLINE
[do] DOI:10.1007/s10886-014-0490-5


  9 / 36 MEDLINE  
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[PMID]:25077507
[Au] Autor:Tomlinson PB; Magellan TM; Griffith MP
[Ad] Endereço:Montgomery Botanical Center 11901 Old Cutler Road, Coral Gables, Florida 33156 USA The Kampong of the National Tropical Botanical Garden, 4013 South Douglas Road, Miami, Florida 33133 USA.
[Ti] Título:Root contraction in Cycas and Zamia (Cycadales) determined by gelatinous fibers.
[So] Source:Am J Bot;101(8):1275-85, 2014 Aug.
[Is] ISSN:1537-2197
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:UNLABELLED: • PREMISE OF THE STUDY: Reaction wood (RW) in seed plants can induce late and usually secondary changes in organ orientation. Conifers produce compression wood (CW), generated by compression tracheids, which generate a push force. Angiosperms produce tension wood (TW), generated by tension wood fibers (TWF) often described as "gelatinous fibers," which exert a pull force. Usually RW is produced eccentrically, but it can occur concentrically, as in aerial roots of Ficus. However, gymnosperms can produce gelatinous fibers (tension fibers, TF), as in cortical and secondary phloem tissues (Gnetum). TFs are therefore limited neither to wood, xylem, nor angiosperms. Here we demonstrate that TFs in secondary phloem are involved in contraction of roots of cycads and compare them with TFs of Ficus.• METHODS: We sectioned root material of cycads at various stages of seedling development using simple staining and histochemical procedures to follow the course of secondary phloem development. Aerial roots of Ficus were compared with the cycad root material.• KEY RESULTS: Tension fibers (gelatinous fibers) occur extensively and continuously in the secondary phloem in roots that undergo contraction. Older tissues, but notably the xylem, become distorted by contraction. TFs in cycads correspond in cell wall features to TFs that occur in Ficus, but do not occur in secondary xylem. The individual fibers visibly contract.• CONCLUSIONS: Tissue contraction in Cycas and Zamia corresponds to that found in angiosperms and Gnetum and further broadens the scope of the activity of tension tissues. This finding possibly indicates that gelatinous fibers originated at a very early period of seed plant evolution.
[Mh] Termos MeSH primário: Cycas/citologia
Floema/citologia
Células Vegetais/fisiologia
Raízes de Plantas/citologia
Zamiaceae/citologia
[Mh] Termos MeSH secundário: Evolução Biológica
Parede Celular
Cycadopsida
Cycas/fisiologia
Ficus/citologia
Gelatina
Gnetum
Floema/fisiologia
Raízes de Plantas/fisiologia
Plântulas/citologia
Plântulas/fisiologia
Xilema/citologia
Zamiaceae/fisiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
9000-70-8 (Gelatin)
[Em] Mês de entrada:1504
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:140801
[St] Status:MEDLINE
[do] DOI:10.3732/ajb.1400170


  10 / 36 MEDLINE  
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[PMID]:24884688
[Au] Autor:Cafasso D; Chinali G
[Ad] Endereço:a Dipartimento di Biologia, Complesso Universitario Monte S. Angelo, Università degli Studi di Napoli "Federico II", Via Cinthia, I-80126 Napoli, Italy.
[Ti] Título:An ancient satellite DNA has maintained repetitive units of the original structure in most species of the living fossil plant genus Zamia.
[So] Source:Genome;57(3):125-35, 2014 Mar.
[Is] ISSN:1480-3321
[Cp] País de publicação:Canada
[La] Idioma:eng
[Ab] Resumo:ZpS1 satellite DNA is specific to the genus Zamia and presents repetitive units organized as long arrays and also as very short arrays dispersed in the genome. We have characterized the structure of the ZpS1 repeats in 12 species representative of the whole geographic distribution of the genus. In most species, the clone most common sequences (cMCS) were so similar that a general most common sequence (GMCS) of the ZpS1 repetitive unit in the genus could be obtained. The few partial variations from the GMCS found in cMCS of some species correspond to variable positions present in most other species, as indicated by the clone consensus sequences (cCS). Two species have an additional species-specific variety of ZpS1 satellite. The dispersed repeats were found to contain more mutations than repeats from long arrays. Our results indicate that all or most species of Zamia inherited the ZpS1 satellite from a common ancestor in Miocene and have maintained repetitive units of the original structure till present. The features of ZpS1 satellite in the genus Zamia are poorly compatible with the model of concerted evolution, but they are perfectly consistent with a new model of satellite evolution based on experimental evidences indicating that a specific amplification-substitution repair mechanism maintains the homogeneity and stability of the repeats structure in each satellite DNA originally present in a species as long as the species exists.
[Mh] Termos MeSH primário: DNA Satélite
Evolução Molecular
Fósseis
Zamiaceae/genética
[Mh] Termos MeSH secundário: Sequência de Bases
Dados de Sequência Molecular
Filogenia
Zamiaceae/classificação
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Satellite)
[Em] Mês de entrada:1501
[Cu] Atualização por classe:161020
[Lr] Data última revisão:
161020
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:140603
[St] Status:MEDLINE
[do] DOI:10.1139/gen-2013-0133



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