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1.
Microb Cell Fact ; 23(1): 78, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38475853

RESUMO

The biosynthetic potency of Taxol by fungi raises their prospective to be a platform for commercial production of Taxol, nevertheless, the attenuation of its productivity with the fungal storage, is the challenge. Thus, screening for a novel fungal isolate inhabiting ethnopharmacological plants, with a plausible metabolic stability for Taxol production could be one of the most affordable approaches. Aspergillus niger OR414905.1, an endophyte of Encephalartos whitelockii, had the highest Taxol productivity (173.9 µg/L). The chemical identity of the purified Taxol was confirmed by HPLC, FTIR, and LC-MS/MS analyses, exhibiting the same molecular mass (854.5 m/z) and molecular fragmentation pattern of the authentic Taxol. The purified Taxol exhibited a potent antiproliferative activity against HepG-2, MCF-7 and Caco-2, with IC50 values 0.011, 0.016, and 0.067 µM, respectively, in addition to a significant activity against A. flavus, as a model of human fungal pathogen. The purified Taxol displayed a significant effect against the cellular migration of HepG-2 and MCF-7 cells, by ~ 52-59% after 72 h, compared to the control, confirming its interference with the cellular matrix formation. Furthermore, the purified Taxol exhibited a significant ability to prompt apoptosis in MCF-7 cells, by about 11-fold compared to control cells, suppressing their division at G2/M phase. Taxol productivity by A. niger has been optimized by the response surface methodology with Plackett-Burman Design and Central Composite Design, resulting in a remarkable ~ 1.6-fold increase (279.8 µg/L), over the control. The biological half-life time of Taxol productivity by A. niger was ~ 6 months of preservation at 4 â„ƒ, however, the Taxol yield by A. niger was partially restored in response to ethyl acetate extracts of E. whitelockii, ensuring the presence of plant-derived signals that triggers the cryptic Taxol encoding genes.


Assuntos
Aspergillus , Paclitaxel , Zamiaceae , Humanos , Aspergillus niger , Endófitos/metabolismo , Células CACO-2 , Cromatografia Líquida , Estudos Prospectivos , Espectrometria de Massas em Tandem , Ciclo Celular
2.
PLoS One ; 19(2): e0284007, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38330066

RESUMO

Ceratozamia morettii, C. brevifrons, and C. tenuis are cycads considered endangered in montane forests in the center of Veracruz state. However, the amount of theoretical and empirical information available on the historical distribution of these species and how they could be affected in the future by the effects of climate change still needs to be increased. Our objective was to generate information on the spatial distribution of the species since the last glacial maximum, present, and future. To map the spatial distribution of species, we created a potential distribution model for each species. The spatial data used for the models included 19 bioclimatic data variables in the present, at the last glacial maximum using two models (CCSM4 and MIROC), and in the future (2080) using two models of the RCP 8.5 scenario of climate change (HadGEM2-CC and MIROC5). We found that each species occupies a unique ecoregion and climatic niche. Ceratozamia morettii and C. tenuis have a similar pattern with an expansion of their distribution area since the last glacial maximum with a larger distribution area in the present and a projected reduction in their distribution under future climatic conditions. For C. brevifrons, we also showed an increase in their distributional area since the last glacial maximum. We also showed that this expansion will continue under future climatic conditions when the species reaches its maximum distributional area. Projections about the future of these endemic cycad species show changes in their habitat, highlighting that temperate zone species (C. morettii and C. tenuis) will face imminent extinction if no effort is made to protect them. On the other hand, the tropical climate species (C. brevifrons) will be favored.


Assuntos
Zamiaceae , Ecossistema , Florestas , México , Mudança Climática
3.
Mol Phylogenet Evol ; 190: 107960, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37918683

RESUMO

The cycad genus Ceratozamia comprises 40 species from Mexico, Guatemala, Belize, and Honduras, where cycads occur throughout climatically varied montane habitats. Ceratozamia has the potential to reveal the history and processes of species diversification across diverse Neotropical habitats in this region. However, the species relationships within Ceratozamia and the ecological trends during its evolution remain unclear. Here, we aimed to clarify the phylogenetic relationships, the timing of clade and species divergences, and the niche evolution throughout the phylogenetic history of Ceratozamia. Genome-wide DNA sequences were obtained with MIG-seq, and multiple data-filtering steps were used to optimize the dataset used to construct an ultrametric species tree. Divergence times among branches and ancestral niches were estimated. The niche variation among species was evaluated, summarized into two principal components, and their ancestral states were reconstructed to test whether niche shifts among branches can be explained by random processes, under a Brownian Motion model. Ceratozamia comprises three main clades, and most species relationships within the clades were resolved. Ceratozamia has diversified since the Oligocene, with major branching events occurring during the Miocene. This timing is consistent with fossil evidence, the timing estimated for other Neotropical plant groups, and the major geological events that shaped the topographic and climatic variation in Mexico. Patterns of niche evolution in the genus do not accord with the Brownian Motion model. Rather, non-random evolution with shifts towards more seasonal environments at high latitudes, or shifts towards humid or dry environments at low latitudes explain the diversification of Ceratozamia. We present a comprehensive phylogenetic reconstruction for Ceratozamia and identify for the first time the environmental factors involved in clade and species diversification within the genus. This study alleviates the controversies regarding the species relationships in the genus and provides the first evidence that latitude-associated environmental factors may influence processes of niche evolution in cycads.


Assuntos
Zamiaceae , Filogenia , Zamiaceae/genética , Filogeografia , Ecossistema , Fatores de Tempo
4.
Phytochemistry ; 217: 113901, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37884257

RESUMO

Macrozamia communis and its associated endophytic fungi are untapped sources of bioactive metabolites with great potential for medicinal exploitation. Chemical investigation of the mycelial extract derived from an endophytic fungus Penicillium sp. MNP-HS-2 associated with M. communis fruit afforded four mycophenolic acid derivatives recognized as previously undescribed natural products (1-4), together with nine known metabolites (5-13). Chemical structures of isolated compounds were determined based on extensive spectroscopic analyses, including 1D/2D NMR and HRESIMS. The absolute stereochemistry of alternatain E (1) was unambiguously established by comparing its experimental and calculated time-dependent density functional theory electronic circular dichroism spectra (TDDFT-ECD). All isolated compounds were assessed for their antimicrobial and cytotoxic activities, where mycophenolic acid methyl ester (7), displayed significant cytotoxic activity against seven different cell lines with IC50 values in the low micromolar to nanomolar range. Mycophenolene A (3) exhibited significant antibacterial activity against Staphylococcus aureus (MIC = 2.1 µg/mL).


Assuntos
Anti-Infecciosos , Antineoplásicos , Penicillium , Zamiaceae , Ácido Micofenólico/farmacologia , Estrutura Molecular , Penicillium/química , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Antineoplásicos/química
5.
Ann Bot ; 130(5): 671-685, 2022 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-36111957

RESUMO

BACKGROUND AND AIMS: Cycads are regarded as an ancient lineage of living seed plants, and hold important clues to understand the early evolutionary trends of seed plants. The molecular phylogeny and spatio-temporal diversification of one of the species-rich genera of cycads, Macrozamia, have not been well reconstructed. METHODS: We analysed a transcriptome dataset of 4740 single-copy nuclear genes (SCGs) of 39 Macrozamia species and two outgroup taxa. Based on concatenated (maximum parsimony, maximum likelihood) and multispecies coalescent analyses, we first establish a well-resolved phylogenetic tree of Macrozamia. To identify cyto-nuclear incongruence, the plastid protein coding genes (PCGs) from transcriptome data are extracted using the software HybPiper. Furthermore, we explore the biogeographical history of the genus and shed light on the pattern of floristic exchange between three distinct areas of Australia. Six key diagnostic characters are traced on the phylogenetic framework using two comparative methods, and infra-generic classification is investigated. KEY RESULTS: The tree topologies of concatenated and multi-species coalescent analyses of SCGs are mostly congruent with a few conflicting nodes, while those from plastid PCGs show poorly supported relationships. The genus contains three major clades that correspond to their distinct distributional areas in Australia. The crown group of Macrozamia is estimated to around 11.80 Ma, with a major expansion in the last 5-6 Myr. Six morphological characters show homoplasy, and the traditional phenetic sectional division of the genus is inconsistent with this current phylogeny. CONCLUSIONS: This first detailed phylogenetic investigation of Macrozamia demonstrates promising prospects of SCGs in resolving phylogenetic relationships within cycads. Our study suggests that Macrozamia, once widely distributed in Australia, underwent major extinctions because of fluctuating climatic conditions such as cooling and mesic biome disappearance in the past. The current close placement of morphologically distinct species in the phylogenetic tree may be related to neotenic events that occurred in the genus.


Assuntos
Cycadopsida , Zamiaceae , Filogenia , Teorema de Bayes , Austrália , Evolução Molecular
6.
Zootaxa ; 5150(3): 428-442, 2022 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-36095653

RESUMO

Two beetles, Ceratophila (Vovidesa) chipjonesi, new species, and Pharaxonotha perezi, new species, (Coleoptera: Erotylidae: Pharaxonothinae) are described from the male cones of the New World cycad Ceratozamia santillanii Prez-Farr. Vovides (Cycadales: Zamiaceae). Morphological analysis and keys are provided for distinguishing these from related beetles inhabiting Ceratozamia in Mexico.


Assuntos
Besouros , Zamiaceae , Animais , Cycadopsida , Masculino , México
7.
Braz J Biol ; 84: e262610, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35766656

RESUMO

The serious blue butterfly, Chilades pandava -Horsfield, 1829- (Lepidoptera: Lycaenidae) is consider one of the main destructive insect pests for ornamental palms Cycas and Zamia. Biological and morphological measurements were carried out of C. pandava stages reared on Cycas revoluta (Cycadaceae) and Zamia encephalartoides (Zamiaceae). In description details, non-significant variations were recorded between the two gender of cycad blue butterfly in the obtained data, but the male adult was more densely blue or violet than female adult. By the aid of SEM, C. pandava all stages were distinct by long and thick hairs covered all the body. The morphometric characters namely, length, width and venation of wings, body length, forewing, hindwing could be as a guide for taxonomic discrimination. The data showed that the life cycle duration of C. pandava was ranged between 20.64 to 21.7 days. The developmental periods of different C. pandava stages are slightly higher on zamia than cycas palms. This investigation detected that a high survival rate was found on Cycas palms (86%) than the survived rate recording on Zamia palms (82%). In the present study, the described morphometric characters could be used as a guide for taxonomic discrimination of this pest. Consequently, this study added a valuable knowledge about C. pandava to have sound decisions for proposal of its management and conservation in Egypt.


Assuntos
Borboletas , Cycas , Zamiaceae , Animais , Feminino , Masculino
8.
Sci Rep ; 12(1): 180, 2022 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-34996996

RESUMO

Pseudomonas aeruginosa is an opportunistic bacterium causing several health problems and having many virulence factors like biofilm formation on different surfaces. There is a significant need to develop new antimicrobials due to the spreading resistance to the commonly used antibiotics, partly attributed to biofilm formation. Consequently, this study aimed to investigate the anti-biofilm and anti-quorum sensing activities of Dioon spinulosum, Dyer Ex Eichler extract (DSE), against Pseudomonas aeruginosa clinical isolates. DSE exhibited a reduction in the biofilm formation by P. aeruginosa isolates both in vitro and in vivo rat models. It also resulted in a decrease in cell surface hydrophobicity and exopolysaccharide quantity of P. aeruginosa isolates. Both bright field and scanning electron microscopes provided evidence for the inhibiting ability of DSE on biofilm formation. Moreover, it reduced violacein production by Chromobacterium violaceum (ATCC 12,472). It decreased the relative expression of 4 quorum sensing genes (lasI, lasR, rhlI, rhlR) and the biofilm gene (ndvB) using qRT-PCR. Furthermore, DSE presented a cytotoxic activity with IC50 of 4.36 ± 0.52 µg/ml against human skin fibroblast cell lines. For the first time, this study reports that DSE is a promising resource of anti-biofilm and anti-quorum sensing agents.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Chromobacterium/efeitos dos fármacos , Extratos Vegetais/farmacologia , Infecções por Pseudomonas/prevenção & controle , Pseudomonas aeruginosa/efeitos dos fármacos , Percepção de Quorum/efeitos dos fármacos , Dermatopatias Bacterianas/prevenção & controle , Zamiaceae , Animais , Antibacterianos/isolamento & purificação , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biofilmes/crescimento & desenvolvimento , Chromobacterium/crescimento & desenvolvimento , Chromobacterium/metabolismo , Modelos Animais de Doenças , Feminino , Regulação Bacteriana da Expressão Gênica , Indóis/metabolismo , Testes de Sensibilidade Microbiana , Extratos Vegetais/isolamento & purificação , Infecções por Pseudomonas/microbiologia , Infecções por Pseudomonas/patologia , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/crescimento & desenvolvimento , Pseudomonas aeruginosa/metabolismo , Ratos , Dermatopatias Bacterianas/microbiologia , Dermatopatias Bacterianas/patologia , Zamiaceae/química
9.
Am J Bot ; 109(1): 151-165, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35025111

RESUMO

PREMISE: Although maintaining the appropriate mid-day timing of the diel thermogenic events of cones of the dioecious cycads Macrozamia lucida and M. macleayi is central to the survival of both plant and pollinator in this obligate pollination mutualism, the nature of the underlying mechanism remains obscure. We investigated whether it is under circadian control. Circadian mechanisms control the timing of many ecologically important processes in angiosperms, yet only a few gymnosperms have been studied in this regard. METHODS: We subjected cones to different ambient temperature and lighting regimens (constant temperature and darkness; stepwise cool/warm ambient temperatures in constant darkness; stepwise dark/light exposures at constant temperature) to determine whether the resulting timing of their thermogenic events was consistent with circadian control. RESULTS: Cones exposed to constant ambient temperature and darkness generated multiple temperature peaks endogenously, with an average interpeak-temperature period of 20.7 (±0.20) h that is temperature-compensated (Q10 = 1.02). Exposure to 24-h ambient temperature cycles (12 h cool/12 h warm, constant darkness) yielded an interpeak-temperature period of 24.0 (±0.05) h, accurately and precisely replicating the ambient temperature period. Exposure to 24-h photo-cycles (12 h light/12 h dark, constant ambient temperature) yielded a shorter, more variable interpeak-temperature period of 23 (±0.23) h. CONCLUSIONS: Our results indicate that cycad cone thermogenesis is under circadian clock control and differentially affected by ambient temperature and light cycles. Our data from cycads (an ancient gymnosperm lineage) adds to what little is known about circadian timing in gymnosperms, which have rarely been studied from the circadian perspective.


Assuntos
Cycadopsida , Zamiaceae , Ritmo Circadiano , Luz , Polinização , Temperatura , Termogênese
10.
Ann Bot ; 130(3): 345-354, 2022 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-34871356

RESUMO

BACKGROUND AND AIMS: We conducted a comprehensive analysis of the functional traits of leaves (leaflets) of cycads. The aim of this study was to clarify the functional divergence between the earlier origin Cycadaceae and the later differentiated Zamiaceae, and the differences in trait associations between cycads and angiosperms. METHODS: We selected 20 Cycadaceae species and 21 Zamiaceae species from the same cycad garden in South China, and measured their leaf structure, economic traits, mechanical resistance (Fp) and leaf water potential at the turgor loss point (πtlp). In addition, we compiled a dataset of geographical distribution along with climatic variables for these cycad species, and some leaf traits of tropical-sub-tropical angiosperm woody species from the literature for comparison. KEY RESULTS: The results showed significantly contrasting leaf trait syndromes between the two families, with Zamiaceae species exhibiting thicker leaves, higher carbon investments and greater Fp than Cycadaceae species. Leaf thickness (LT) and πtlp were correlated with mean climatic variables in their native distribution ranges, indicating their evolutionary adaptation to environmental conditions. Compared with the leaves of angiosperms, the cycad leaves were thicker and tougher, and more tolerant to desiccation. Greater Fp was associated with a higher structural investment in both angiosperms and cycads; however, cycads showed lower Fp at a given leaf mass per area or LT than angiosperms. Enhancement of Fp led to more negative πtlp in angiosperms, but the opposite trend was observed in cycads. CONCLUSIONS: Our results reveal that variations in leaf traits of cycads are mainly influenced by taxonomy and the environment of their native range. We also demonstrate similar leaf functional associations in terms of economics, but different relationships with regard to mechanics and drought tolerance between cycads and angiosperms. This study expands our understanding of the ecological strategies and likely responses of cycads to future climate change.


Assuntos
Magnoliopsida , Zamiaceae , Carbono , Cycadopsida , Secas , Magnoliopsida/fisiologia , Folhas de Planta/fisiologia , Água/fisiologia
11.
Ann Bot ; 128(5): 577-588, 2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34265043

RESUMO

BACKGROUND AND AIMS: The gymnosperm order Cycadales is pivotal to our understanding of seed-plant phylogeny because of its phylogenetic placement close to the root node of extant spermatophytes and its combination of both derived and plesiomorphic character states. Although widely considered a 'living fossil' group, extant cycads display a high degree of morphological and anatomical variation. We investigate stomatal development in Zamiaceae to evaluate variation within the order and homologies between cycads and other seed plants. METHODS: Leaflets of seven species across five genera representing all major clades of Zamiaceae were examined at various stages of development using light microscopy and confocal microscopy. KEY RESULTS: All genera examined have lateral subsidiary cells of perigenous origin that differ from other pavement cells in mature leaflets and could have a role in stomatal physiology. Early epidermal patterning in a 'quartet' arrangement occurs in Ceratozamia, Zamia and Stangeria. Distal encircling cells, which are sclerified at maturity, are present in all genera except Bowenia, which shows relatively rapid elongation and differentiation of the pavement cells during leaflet development. CONCLUSIONS: Stomatal structure and development in Zamiaceae highlights some traits that are plesiomorphic in seed plants, including the presence of perigenous encircling subsidiary cells, and reveals a clear difference between the developmental trajectories of cycads and Bennettitales. Our study also shows an unexpected degree of variation among subclades in the family, potentially linked to differences in leaflet development and suggesting convergent evolution in cycads.


Assuntos
Zamiaceae , Cycadopsida , Fósseis , Filogenia , Sementes
12.
Carbohydr Polym ; 261: 117831, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33766335

RESUMO

Arabinogalactan-proteins (AGPs), important signalling molecules of the plant cell wall, are structurally extensively investigated in angiosperms, but information on AGPs in gymnosperms is still limited. We characterized AGPs from the gymnosperms Ginkgo biloba, Ephedra distachya, Encephalartos longifolius and Cycas revoluta. The protein contents are comparable to that of angiosperm AGPs. Hydroxyproline is the site of linking the carbohydrate part and was detected in all AGPs with highest concentration in Cycas AGP (1.1 % of the AGP). Interestingly, with the exception of Cycas, all AGPs contained the monosaccharide 3-O-methylrhamnose not present in angiosperm polysaccharides. The carbohydrate moieties of Cycas and Ephredra showed the main components 1,3,6-linked galactose and terminal arabinose typical of angiosperm AGPs, whereas that of Ginkgo AGP was unique with 1,4-linked galactose as dominant structural element. Bioinformatic search for glycosyltransferases in Ginkgo genome also revealed a lower number of galactosyltransferases responsible for biosynthesis of the 1,3-Gal/1,6-Gal AGP backbone.


Assuntos
Parede Celular/química , Cycadopsida/química , Mucoproteínas/química , Evolução Biológica , Sequência de Carboidratos , Parede Celular/metabolismo , Biologia Computacional , Cycadopsida/classificação , Cycadopsida/metabolismo , Cycas/química , Cycas/metabolismo , Ephedra/química , Ephedra/metabolismo , Galactanos/química , Ginkgo biloba/química , Ginkgo biloba/metabolismo , Estrutura Molecular , Mucoproteínas/isolamento & purificação , Mucoproteínas/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/metabolismo , Conformação Proteica , Zamiaceae/química , Zamiaceae/metabolismo
13.
Phytochemistry ; 186: 112715, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33721794

RESUMO

Cycad cone thermogenesis and its associated volatiles are intimately involved in mediating the behavior of their obligate specialist pollinators. In eastern Australia, thrips in the Cycadothrips chadwicki species complex are the sole pollinators of many Macrozamia cycads. Further, they feed and reproduce entirely in the pollen cones. M. miquelii, found only in the northern range of this genus, is pollinated only by a C. chadwicki cryptic species that is the most distantly related to others in the complex. We examined the volatile profile from M. miquelii pollen and ovulate (receptive and non-receptive) cones to determine how this mediates pollination mechanistically, using GC-MS (gas chromatography-mass spectrometry) and behavioral tests. Monoterpenes comprise the bulk of M. miquelii volatile emissions, as in other Macrozamia species, but we also identified compounds not reported previously in any cycad, including three aliphatic esters (prenyl acetate and two of uncertain identity) and two aliphatic alcohols. The two unknown esters were confirmed as prenyl (3-methylbut-2-enyl) esters of butyric and crotonic ((E))-but-2-enoic) acids after chemical synthesis. Prenyl crotonate is a major component in emissions from pollen and receptive ovulate cones, is essentially absent from non-receptive cones, and has not been reported from any other natural source. In field bioassays, Cycadothrips were attracted only to those volatile treatments containing prenyl crotonate. We discuss M. miquelii cone odorants relative to those of other cycads, especially with respect to prenyl crotonate being a species-specific signal to this northern C. chadwicki cryptic species, and how this system may have diversified.


Assuntos
Tisanópteros , Zamiaceae , Animais , Austrália , Flores , Polinização , Simbiose
14.
Nat Prod Res ; 35(23): 5166-5176, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32643403

RESUMO

Given the lack of adequate research on Dioon spinulosum (D. spinulosum) Dyer Ex Eichler, this study was conducted focusing on different biological activities and phytochemical investigation of D. spinulosum for the first time. D. spinulosum showed strong protective activity against DNA damage and potent activity against VERO cell line. It also presented antimicrobial and hepatoprotective activity. Phytochemical investigation of the leaves resulted in isolation of two new flavonoids, apigenin 7-O-α-d-glucopyranoside (15) and amentoflavone 7-O-α-l-rhamnopyranoside (16), in addition to fifteen known compounds: phytone (1), trans-phytol (2), ß-sitosterol (3), stigmasterol (4), oliveriflavone (5), 7,4',7″,4″'-tetramethylamentoflavone (6), 7,4',7''-trimethylamentoflavone (7), scaidopitysin (8), bilobetin (9), isoginkgetin (10), aromadendrin (11), sotusflavone (12), engeletin (14) and eriocitrin (17) for the first time together with amentoflavone (13). Compounds (11) and (13) displayed very strong cytotoxic activity and showed the highest protective activity against DNA damage.


Assuntos
Anti-Infecciosos , Zamiaceae , Antioxidantes/farmacologia , Flavonoides/farmacologia , Extratos Vegetais/farmacologia , Folhas de Planta
15.
New Phytol ; 227(6): 1872-1884, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32392621

RESUMO

Niche conservatism is the tendency of lineages to retain the same niche as their ancestors. It constrains biological groups and prevents ecological divergence. However, theory predicts that niche conservatism can hinder gene flow, strengthen drift and increase local adaptation: does it mean that it also can facilitate speciation? Why does this happen? We aim to answer these questions. We examined the variation of chloroplast DNA, genome-wide single nucleotide polymorphisms, morphological traits and environmental variables across the Dioon merolae cycad populations. We tested geographical structure, scenarios of demographic history, and niche conservatism between population groups. Lineage divergence is associated with the presence of a geographical barrier consisting of unsuitable habitats for cycads. There is a clear genetic and morphological distinction between the geographical groups, suggesting allopatric divergence. However, even in contrasting available environmental conditions, groups retain their ancestral niche, supporting niche conservatism. Niche conservatism is a process that can promote speciation. In D. merolae, lineage divergence occurred because unsuitable habitats represented a barrier against gene flow, incurring populations to experience isolated demographic histories and disparate environmental conditions. This study explains why cycads, despite their ancient lineage origin and biological stasis, have been able to diversify into modern ecosystems worldwide.


Assuntos
Zamiaceae , Ecossistema , Especiação Genética , Geografia , México , Filogenia
16.
Mol Phylogenet Evol ; 139: 106530, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31176968

RESUMO

Evidence suggests that past climatic fluctuations affected speciation of extant cycads. However, empirical genetic and morphological evidence explaining patterns and processes of species diversification are scarce. There are some explanations for the origin and evolution of the genus Ceratozamia, but with inconclusive results. To elucidate the evolution of Ceratozamia, we used genetic and phenotypic sources as empirical data, which were applied in a 'proximate-ultimate' framework (ecological and evolutionary scale, respectively). Our results suggested that the evolutionary mechanisms of speciation were shaped by deterministic (natural selection-adaptation) driven by climatic conditions associated to water stress, and probably enhanced by stochastic processes (gene drift and inbreeding). In general terms, punctuated evolution models were those that best explained the patterns of speciation throughout the phylogenetic history of the lineages encompassed in the genus Ceratozamia. Finally, we provide empirical evidence on the tempo and mode of the evolution of a 'living plant fossil'.


Assuntos
Evolução Biológica , Zamiaceae/anatomia & histologia , Animais , Fósseis , Especiação Genética , Fenótipo , Filogenia , Filogeografia , Tamanho da Amostra , América do Sul , Especificidade da Espécie , Fatores de Tempo , Zamiaceae/genética
17.
PLoS One ; 14(2): e0211271, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30726265

RESUMO

Cycads are among the few plants that have developed specialized roots to host nitrogen-fixing bacteria. We describe the bacterial diversity of the coralloid roots from seven Dioon species and their surrounding rhizosphere and soil. Using 16S rRNA gene amplicon sequencing, we found that all coralloid roots are inhabited by a broad diversity of bacterial groups, including cyanobacteria and Rhizobiales among the most abundant groups. The diversity and composition of the endophytes are similar in the six Mexican species of Dioon that we evaluated, suggesting a recent divergence of Dioon populations and/or similar plant-driven restrictions in maintaining the coralloid root microbiome. Botanical garden samples and natural populations have a similar taxonomic composition, although the beta diversity differed between these populations. The rhizosphere surrounding the coralloid root serves as a reservoir and source of mostly diazotroph and plant growth-promoting groups that colonize the coralloid endosphere. In the case of cyanobacteria, the endosphere is enriched with Nostoc spp and Calothrix spp that are closely related to previously reported symbiont genera in cycads and other early divergent plants. The data reported here provide an in-depth taxonomic characterization of the bacterial community associated with coralloid root microbiome. The functional aspects of the endophytes, their biological interactions, and their evolutionary history are the next research step in this recently discovered diversity within the cycad coralloid root microbiome.


Assuntos
Bactérias Fixadoras de Nitrogênio/classificação , Análise de Sequência de DNA/métodos , Zamiaceae/microbiologia , Biodiversidade , DNA Ribossômico/genética , Endófitos/classificação , Endófitos/genética , Endófitos/isolamento & purificação , Bactérias Fixadoras de Nitrogênio/genética , Bactérias Fixadoras de Nitrogênio/isolamento & purificação , Filogenia , Raízes de Plantas/microbiologia , RNA Ribossômico 16S/genética , Rizosfera , Zamiaceae/classificação
18.
J Ethnobiol Ethnomed ; 15(1): 4, 2019 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-30658655

RESUMO

BACKGROUND: This study documents cycad-human relationships in Mexico, Belize, Guatemala, El Salvador, and Honduras over the last 6000 years. The impetus was acute need for a better understanding of previously undocumented uses of cycads in this region, and the need to improve cycad conservation strategies using ethnobotanical data. We hypothesized that cycads are significant dietary items with no long-term neurological effects, are important to religious practice, and contribute to cultural identity and sense of place, but that traditional knowledge and uses are rapidly eroding. Guiding questions focused on nomenclature, food and toxicity, relationships to palms and maize, land management issues, roles in religious ceremony, and medicinal uses, among others, and contributions of these to preservation of cycads. METHODS: From 2000 to 2017, the authors conducted 411 semi-structured ethnographic interviews, engaged in participant-observation in Mexican and Honduran communities, and carried out archival research and literature surveys. RESULTS: We documented 235 terms and associated uses that 28 ethnic groups have for 57 species in 19 languages across 21 Mexican states and 4 Central American nations. Carbohydrate-rich cycads have been both famine foods and staples for at least six millennia across the region and are still consumed in Mexico and Honduras. Certain parts are eaten without removing toxins, while seed and stem starches are detoxified via several complex processes. Leaves are incorporated into syncretic Roman Catholic-Mesoamerican religious ceremonies such as pilgrimages, Easter Week, and Day of the Dead. Cycads are often perceived as ancestors and protectors of maize, revealing a close relationship between both groups. Certain beliefs and practices give cycads prominent roles in conceptions of sense of place and cultural heritage. CONCLUSIONS: Cycads are still used as foods in many places. Though they do not appear to cause long-term neurological damage, their health effects are not fully understood. They are often important to religion and contribute to cultural identity and sense of place. However, because most traditional knowledge and uses are rapidly eroding, new community-based biocultural conservation efforts are needed. These should incorporate tradition where possible and seek inspiration from existing successful cases in Honduras and Mexico.


Assuntos
Etnobotânica , Zamiaceae , Belize , Culinária , El Salvador , Etnicidade , Guatemala , Honduras , Humanos , Entrevistas como Assunto , México , Plantas Comestíveis , Plantas Medicinais , Terminologia como Assunto
19.
Pak J Biol Sci ; 22(10): 477-485, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31930837

RESUMO

BACKGROUND AND OBJECTIVE: Cycas revoluta and Zamia encephalartoides were commercially ornamental palms. Butterfly, Chilades pandava was an important pest of ornamental palms either cycas or zamia. Impact factors on C. pandava infestations on cycas and zamia palms were studied. MATERIALS AND METHOD: Two field experiments were carried out during the period from 1st January-15th December, 2018 in a private palm nursery at Abu-Ghaleb village, Giza, Egypt to study the infestation of C. pandava on cycas and zamia palms and also, provided its control strategies. RESULTS: The infested percent of C. pandava was recorded the highest values at 1st week of May and September, 2018 with 63.89 % on cycas palms. Whereas, the high value of the infestation percent was 66.67% on zamia palms. A positive effect was reported with maximum and minimum temperatures but a negative effect was recorded with average RH% on C. pandava infestations. The increasing of the C. pandava infestations decreased these 2 plant enzymes, peroxidase and phenoloxidase. The average reduction percentages of the tested 9 pesticides against C. pandava infestations on cycas palms were markedly higher in case of sulfur 70% SC and fipronil 80% WG being 69.88 and 61.30% reductions than other treatments after 3 sequential applications throughout 3 months, respectively. CONCLUSION: Chilades pandava infestation was higher on cycas palms than zamia palms. Sulfur and Fipronil were more efficacy pesticides against this pest.


Assuntos
Borboletas/fisiologia , Cycas/fisiologia , Inseticidas , Zamiaceae/fisiologia , Animais , Egito , Peroxidases/metabolismo , Controle de Pragas/métodos , Doenças das Plantas , Estações do Ano , Enxofre
20.
Zootaxa ; 4508(2): 151-178, 2018 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-30485971

RESUMO

Ceratophila new genus (Erotylidae: Pharaxonothinae) inhabiting male cones of the Mesoamerican cycad genus Ceratozamia Brongniart (Zamiaceae) is described for seven new species and compared to other genera of the Pharaxonothinae. Ceratophila differs from other genera of the Pharaxonothinae in many characters, most notable of which are: lateral pronotal carina thicker anteriorly in lateral view; head with supraocular and transverse occipital lines; elytra lacking a basal bead; and stridulatory files at base of head narrowly separated. Ceratophila has the male genitalia laterally compressed with a short median lobe and flagellum, similar to other Erotylidae. In comparison, the most superficially similar pharaxonothine genus Pharaxonotha Reitter has: lateral pronotal carina thin along entire length; head lacking supraocular lines, but with transverse occipital lines; elytra with distinct basal bead; stridulatory files at base of head widely separated; and unique male genitalia that are dorsoventrally flattened with a long median lobe and flagellum. Ceratophila contains two subgenera, which differ most notably in external characters and sexual dimorphism. Members of Ceratophila (Ceratophila), the nominal subgenus, have: more cylindrical bodies, pronotum evenly convex dorsally; the pronotum lacking basal longitudinal grooves on disc; metatibiae that are distinctly triangularly dilated toward apex; and no apparent external sexual dimorphism. In comparison, members of Ceratophila (Vovidesa) new subgenus have: dorsoventrally flattened bodies; the pronotum explanate (concave) along lateral margins; the pronotum with basal longitudinal grooves on disc; metatibiae weakly or not dilated toward apex; and with all tibiae in males showing strong sexual dimorphism. Four new species are described within the subgenus Ceratophila: C. (C.) chemnicki, C. (C.) gregoryi, C. (C.) picipennis, C. (C.) sanchezae; and three new species are described within the subgenus Vovidesa: C. (V.) chiapensis, C. (V.) mixeorum, C. (V.) vazquezi. Keys to genera, subgenera and species of known adults based on morphology are provided.


Assuntos
Besouros , Zamiaceae , Distribuição Animal , Estruturas Animais , Animais , Tamanho Corporal , Cycadopsida , Masculino , Tamanho do Órgão
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