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1.
Environ Monit Assess ; 193(4): 208, 2021 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-33755795

RESUMO

Increasing gaseous emissions of nitrogen (N) and sulfur (S) associated with oil sands development in northern Alberta (Canada) has led to changing regional wet and dry N and S deposition regimes. We assessed the potential for using bog plant/lichen tissue chemistry (N and S concentrations, C:N and C:S ratios, in 10 plant/lichen species) to monitor changing atmospheric N and S deposition through sampling at five bog sites, 3-6 times per growing season from 2009 to 2016. During this 8-year period, oil sands N emissions steadily increased, while S emissions steadily decreased. We examined the following: (1) whether each species showed changes in tissue chemistry with increasing distance from the Syncrude and Suncor upgrader stacks (the two largest point sources of N and S emissions); (2) whether tissue chemistry changed over the 8 year period in ways that were consistent with increasing N and decreasing S emissions from oil sands facilities; and (3) whether tissue chemistry was correlated with growing season wet deposition of NH4+-N, NO3--N, or SO42--S. Based on these criteria, the best biomonitors of a changing N deposition regime were Evernia mesomorpha, Sphagnum fuscum, and Vaccinium oxycoccos. The best biomonitors of a changing S deposition regime were Evernia mesomorpha, Cladonia mitis, Sphagnum fuscum, Sphagnum capillifolium, Vaccinium oxycoccos, and Picea mariana. Changing N and S deposition regimes in the oil sands region appear to be influencing N and S cycling in what once were pristine ombrotrophic bogs, to the extent that these bogs may effectively monitor future spatial and temporal patterns of deposition.


Assuntos
Líquens , Áreas Alagadas , Alberta , Ascomicetos , Monitoramento Ambiental , Nitrogênio/análise , Campos de Petróleo e Gás , Parmeliaceae , Enxofre/análise
2.
Sci Total Environ ; 764: 142875, 2021 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-33757245

RESUMO

Lichens contribute significantly to the biodiversity and functioning of many ecosystems. Although lichens are useful air pollution bioindicators and may respond in significant ways to global change, they are studied infrequently under field conditions in chamberless exposure systems. We surveyed corticolous lichens on paper birch (Betula papyrifera) and trembling aspen (Populus tremuloides) after 10 years exposure (1998-2007) to elevated CO2 (eCO2) and O3 (eO3) in the Aspen-FACE experiment in Rhinelander, WI, USA. This experiment utilized chamberless exposure rings, 30 m in diameter, with both host trees planted together in one quadrant. Four treatments were allocated among 12 rings: ambient, eCO2, eO3, and the combination of eCO2 + eO3, each replicated once in each of three blocks. Over the course of the experiment, ambient CO2 increased from 343 to 386 ppm while eCO2 averaged ~530 ppm CO2. Ambient ozone concentrations averaged ~37 ppb and ~49 ppb for eO3 although exposures decreased with time. Tree growth and leaf area index were negatively affected by eO3 and stimulated by eCO2, resulting in higher photosynthetically active radiation (PAR) in eO3 and lower in eCO2. We assessed lichen richness and cover on five host trees per ring on the north-facing side of the trunks, which were higher on birch than on aspen. Neither of the lichen measures on birch responded to the exposure treatments, while on aspen lichen cover was highest in eO3 and lowest in eCO2. On aspen, lichen cover was positively related to PAR and dominated by Caloplaca. No relationship was found for birch, although Lecanora exhibited a negative relationship with PAR. These lichens were insensitive to direct effects of eCO2 and eO3 at the levels applied. Instead, they responded to indirect effects, such as host tree species, and changes in understory PAR, resulting from direct effects of eO3 and eCO2 on the host trees.


Assuntos
Líquens , Ozônio , Dióxido de Carbono/toxicidade , Ecossistema , Ozônio/toxicidade , Árvores
3.
Environ Monit Assess ; 193(4): 198, 2021 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-33730196

RESUMO

We investigated the association between air pollution and asthma and bronchitis hospital admissions in Algiers city (Algeria). In addition, we used geographic information systems (GIS) and statistical methods to evaluate their correlation with the atmospheric pollution estimated by the lichen biomonitoring method of the index of atmospheric purity (IAP), the index of human impact (IHI) and environmental parameters. Thus, we georeferenced 976 local patients (including 771 patients with asthma and 205 patients with bronchitis). Then, we compared the patients to the spatial distribution of IAP in thirty-five areas (communities). The results revealed a significant difference in the mean spatial variation in the diseases among those areas. In fact, maps and generalized linear models (GLMs) revealed a significant negative correlation between IAP and diseases. Therefore, redundancy analysis (RDA) and Monte Carlo tests described a significant effect of IAP, urbanization and the number of roads on the distribution of diseases. We hope our findings contribute to enriching the literature on health research with a low-cost method of monitoring outdoor air pollution.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Asma , Bronquite , Líquens , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Argélia , Asma/epidemiologia , Baías , Monitoramento Biológico , Cidades , Monitoramento Ambiental , Sistemas de Informação Geográfica , Humanos
4.
Molecules ; 26(4)2021 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-33672591

RESUMO

The present study provides new data concerning the chemical characterisation of Physcia mediterranea Nimis, a rare Mediterranean species belonging to the family Physciaceae. The phytochemical screening was carried out using GC-MS, HPLC-ESI-MS-MS, and NMR techniques. Hot extraction of n-hexane was carried out, followed by separation of the part insoluble in methanol: wax (WA-hex), from the part soluble in methanol (ME-hex). GC-MS analysis of the ME-hex part revealed the presence of methylbenzoic acids such as sparassol and atraric acid and a diterpene with a kaurene skeleton which has never been detected before in lichen species. Out of all the compounds identified by HPLC-ESI-MS-MS, sixteen compounds are common between WA-hex and ME-hex. Most are aliphatic fatty acids, phenolic compounds and depsides. The wax part is characterised by the presence of atranorin, a depside of high biological value. Proton 1H and carbon 13C NMR have confirmed its identification. Atranol, chloroatranol (depsides compound), Ffukinanolide (sesquiterpene lactones), leprolomin (diphenyl ether), muronic acid (triterpenes), and ursolic acid (triterpenes) have also been identified in ME-hex. The results suggested that Physcia mediterranea Nimis is a valuable source of bioactive compounds that could be useful for several applications as functional foods, cosmetics, and pharmaceuticals.


Assuntos
Líquens/química , Compostos Fitoquímicos/análise , Estrutura Molecular , Especificidade da Espécie
5.
Sci Total Environ ; 771: 144834, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33548716

RESUMO

The lichen Scots pine forests habitats are undergoing rapid disappearance across Europe. Due to the semi-natural character of this habitat and an increase of the nitrification as a result of air pollution, determination of factors responsible for the decrease in lichen field layer cover requires a comprehensive approach. Our study aimed to investigate environmental factors necessary for the determination of active protection measures in order to maintain this vulnerable habitat. Specifically, we aimed to investigate: 1) the environmental factors influencing lichen cover in the lichen Scots pine forests of Bory Tucholskie National Park; 2) the differences in habitat variables between sites with lichen-rich and bryophyte-rich field layers. In our study, we used vegetation and microhabitat properties data collected over three years of surveys, as well as ALS LiDAR data. Our results indicated that lichen and bryophyte cover, tree height, tree cover, thickness of organic matter layer, soil temperature and soil water content differed between lichen-rich and bryophyte-rich sites. We found a significant negative relationship between lichen cover recorded within the field layer and tree height. The lichen-rich field layer developed better in areas with lower tree height and thinner layer of organic matter, which created a favorable habitat conditions for lichen development. Our research revealed the previously unknown impact of tree height for the development of lichen field layer. These findings can be used to plan the active conservation measures of lichen Scots pine forests.


Assuntos
Líquens , Ecossistema , Europa (Continente) , Florestas , Árvores
6.
Sci Total Environ ; 771: 145360, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33548723

RESUMO

Epiphytic and epixylic lichens respond negatively to forest degradation, climate change and pollution, but those effects may depend on functional traits or interact with the stage of tree decay. Disentangling the main drivers of lichen communities remains a challenge in regions where lichens are diverse and poorly known, as the case of Patagonian temperate forests. We used a multi-scale approach to evaluate the relationship between environmental variables, tree decay stage and lichens. We sampled lichens across three increasing scales (tree â‰ª site â‰ª landscape) by selecting 19 landscape units, where trees in four decay stages (snags, logs, cavity trees and healthy trees) were selected within sampling plots. A total of 35 predictors were measured over different scales, including 25 remote sensing indices of forest conditions, climate and air pollutants. Structural Equation Models were used to test the causal linkages of predictors with lichens, distinguishing functional categories (size, growth and reproductive strategy). A total of 69 lichen species were recorded. Cavity trees and logs supported the largest diversity, while snags and healthy trees had the lowest diversity. Functional lichen groups responded differently to fine-scale variables, including the diameter, height, density and pH of trees. Air pollutants affected species with sexual and mixed strategies. Lichens were sensitive to precipitation, temperature and wind speed, with foliose and sexual species responding positively to the latter. The abundance of all species and macrolichens increased with tree senescence and decreased with canopy continuity. Lichens occupying snags and logs responded negatively to primary productivity and tree senescence, but positively to soil organic matter. Our findings suggest: i) the functional structure of lichen communities varies non-linearly with the wood decay process; ii) the reproductive strategy influences the sensitivity to air pollutants, iii) climate variables influence dispersal and colonization of woody substrates; and iv) forest structure/succession interacts with tree decay.


Assuntos
Poluentes Atmosféricos , Líquens , Mudança Climática , Florestas , Árvores
7.
Planta ; 253(1): 14, 2021 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-33392847

RESUMO

MAIN CONCLUSION: During desiccation, both apparent electron transport rate (ETRapp) and photosynthetic CO2 uptake peak when external water has evaporated. External water, causing suprasaturation, weakens the strong correlation between ETRapp and CO2 uptake. Lichens are poikilohydric organisms passively regulated by ambient conditions. In theory, apparent electron transport rate (ETRapp), estimated by photosystem II yield measured in light (ΦPSII), is a proxy of photosynthetic CO2 uptake. Hydration level, however, is a complicating factor, particularly during suprasaturation that strongly reduces CO2 diffusion. Here, the cephalolichen Lobaria pulmonaria and two chlorolichens Parmelia sulcata and Xanthoria aureola were excessively hydrated before photosynthetic CO2 uptake and ΦPSII using imaging fluorescence tools were simultaneously measured while drying at 200 µmol photons m-2 s-1. CO2 uptake peaked when hydration had declined to a level equivalent to their respective internal water holding capacity (WHCinternal) i.e., the water per thallus area after blotting external water. CO2 uptake and ETRapp in all species were highly correlated at hydration levels below WHCinternal, but weaker at higher hydration (chlorolichens) or absent (cephalolichen). Yet, at a specimen level for the two chlorolichens, the correlation was strong during suprasaturation. The CO2 uptake-ETRapp relationship did not differ between measured species, but may vary between other lichens because the slope depends on cortical transmittance and fraction of electrons not used for CO2 uptake. For new lichen species, calibration of ETRapp against CO2 uptake is therefore necessary. At intrathalline scales, ΦPSII during drying initially increased along thallus margins before reaching maximum values in central portions when hydration approached WHCinternal. WHCinternal represents the optimal hydration level for lichen photosynthesis. In conclusion, ETRapp is an easily measured and reliable proxy of CO2 uptake in thalli without external water but overestimates photosynthesis during suprasaturation.


Assuntos
Dióxido de Carbono , Transporte de Elétrons , Líquens , Ascomicetos/metabolismo , Dióxido de Carbono/metabolismo , Clorofila , Líquens/metabolismo , Luz , Parmeliaceae/metabolismo , Fotossíntese/fisiologia
8.
Environ Monit Assess ; 193(2): 101, 2021 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-33515080

RESUMO

The lichen species Parmotrema tinctorum (Nyl.) Hale was transplanted in two cities-Tezpur (small) and Guwahati (large)-of the Brahmaputra Valley to assess the impact of air pollution on the anatomy and physiology, and accumulation of pollutants. Significant damage to the anatomy was observed in samples, and the degree of damage was found to be higher in the transplants of the larger city. In the lichen transplants from locations having high traffic density, the total chlorophyll content was found to fall; on the contrary, electrical conductivity was found to be higher. The exposed-to-control ratio showed severe accumulation of Cd in all the transplants. Elements such as Cd, Pb, and Zn were found to be enriched in all the lichen samples from both Guwahati as well as Tezpur city. Besides, Cr, Cu, K, and Ni were also realized to be enhanced to a moderate extent. The correlations of indicator metal species pairs showed that anthropogenic influence was quite clear.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Líquens , Metais Pesados , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Cidades , Monitoramento Ambiental , Índia , Metais Pesados/análise , Parmeliaceae
9.
Oecologia ; 195(2): 489-497, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33394128

RESUMO

Cloud forests have been found to lose more nitrogen in stream discharge than they gain from atmospheric deposition. They also support a large diversity and biomass of tree epiphytes, predominately composed of cryptogams. Since cryptogam epiphytes harbor nitrogen fixing cyanobacteria, they may help make up for the nitrogen loss from ecosystems. We assessed cryptogam biomass on the ground, boles and branches in Quercus costaricensis dominated stands near the tree line in the Cordillera de Talamanca, Costa Rica. Nitrogen fixation was assayed using 15N2 uptake. Total cryptogam biomass was 2 977 kg ha-1, with 67% being found on the lower branches. Bryophytes and chlorolichens made up 53% and 44%, respectively, of the biomass. Half of the bryophyte mass was composed of the liverwort Plagiochila heterophylla, and 66% of the chlorolichen of Lobariella pallida. There were no significant differences in nitrogen fixation rates between the cryptogam species, with a mean rate of 5.04 µg N g-1 day-1 during the predominantly wet condition in the forest. The overall nitrogen input from fixation was 6.1 kg N ha-1 year-1, of which 78% came from bryophytes, 18% from chlorolichens, and 4% from cyanolichens. Only 2.0% of the fixation occurred in cryptogams on the ground, whereas 67%, 24%, and 7% occurred on the lower branches, boles, and upper branches, respectively. These results show that tree epiphytes constitute a significant source of nitrogen for these forests, due to the trees' large surface area, and can make up for the nitrogen lost from these ecosystems.


Assuntos
Líquens , Fixação de Nitrogênio , Ascomicetos , Biomassa , Costa Rica , Ecossistema , Florestas , Nitrogênio/análise , Árvores
10.
Am J Bot ; 108(1): 159-171, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33512730

RESUMO

PREMISE: Lichens are one of the main structural components of plant communities in the North American boreal biome. They play a pivotal role in lichen woodlands, a large ecosystem situated north of the closed-crown forest zone, and south of the forest-tundra zone. In Eastern Canada (Quebec), there is a remnant LW found 500 km south of its usual distribution range, in the Parc National des Grands-Jardins, originated mainly because of wildfires. We inferred the origin of the lichen Cladonia stellaris from this LW and assessed its genetic diversity in a postfire succession. METHODS: We genotyped 122 individuals collected across a latitudinal gradient in Quebec. Using the software Stacks, we compared four different approaches of locus selection and single-nucleotide polymorphism calling. We identified the best fitting approach to investigate population structure and estimate genetic diversity of C. stellaris. RESULTS: Populations in southern Quebec are not genetically different from those of northern LWs. The species consists of at least four phylogenetic lineages with elevated levels of genetic diversity and low co-ancestry. In Parc National des Grands-Jardins, we reported high values of genetic diversity not related with time since fire disturbance and low genetic differentiation among populations with different fire histories. CONCLUSIONS: This first population genomic study of C. stellaris is an important step forward to understand the origin and biogeographic patterns of lichen woodlands in North America. Our findings also contribute to the understanding of the effect of postfire succession on the genetic structure of the species.


Assuntos
Líquens , Rena , Animais , Ascomicetos , Canadá , Ecossistema , Florestas , Líquens/genética , Metagenômica , América do Norte , Filogenia , Quebeque , Estados Unidos
11.
Sci Total Environ ; 750: 141439, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32882488

RESUMO

Certain lichens are effective colonisers of polluted sites. However, little is known about the tolerance of photobionts and the degree of mycobiont selectivity to photobionts relative to metal pollution. The present study recognises the genetic and anatomical diversity of Asterochloris photobionts in epigeic lichens, i.e. Cladonia cariosa, C. rei, and Diploschistes muscorum, in relation to a wide spectrum of soil pollution. In accordance with phylogenetic analysis, photobionts were clustered in 7 moderately- to well-supported clades, including 19 haplotypes. The mycobionts of all studied lichens demonstrated a low level of selectivity and were capable of associating with various Asterochloris lineages. This tendency was also expressed by the frequent (~25%) occurrence of multiple algal genotypes in a single thallus. This indicates that identified Asterochloris lineages are generally tolerant to heavy-metal pollution, and the low level of selectivity of mycobionts enables them to select the most suitable and/or available partner. The trend of increasing incidence of certain Asterochloris lineages and decreasing frequency of others along with increasing soil pollution was observed. This proves the superior adaptation of some photobionts to polluted sites. Such symbiotic plasticity constitute an adaptive feature necessary for the successful colonisation. High number of haplotypes at polluted sites could be the result of multiple introduction events from different areas during the initial stages of spontaneous succession. Regardless of the genetic pattern, Asterochloris cells were considerably smaller, and the density and compaction of cells in the algal layer were higher, in lichen specimens from polluted sites, indicating that photobiont characteristics may be closely dependent on heavy-metal pollution.


Assuntos
Líquens , Metais Pesados , Ecossistema , Poluição Ambiental , Filogenia , Simbiose
12.
Zootaxa ; 4878(3): zootaxa.4878.3.10, 2020 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-33311150

RESUMO

The Brazilian genus Machima Brunner von Wattenwyl, 1878 includes three valid species: M. paranensis Rehn, 1950 and M. scalprum Rehn, 1950 distributed on Southern and M. phyllacantha (Burmeister, 1838) from Northeastern Brazil. Herein we analyzed eleven male specimens of Machima from Parque Nacional de Itatiaia and propose a new species. Machima itatiaia sp. nov. is characterized by its main lobe of the cercus curving abruptly on apical two-thirds and accessory lobe as long as wide. The new species is the first record of the genus from Southeastern Brazil. Finally, we also present a key to species of Machima based on males.


Assuntos
Líquens , Ortópteros , Animais , Brasil , Florestas , Masculino
13.
Phytochemistry ; 180: 112521, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33099129

RESUMO

Three undescribed stictanes, nieblastictanes A-C, two flavicanes, nieblaflavicanes A and B, together with three already reported stictanes, along with the known compounds (+)-usnic acid, sekikaic acid, divaricatic acid, and divaricatinic acid methyl ester were isolated from an ethyl acetate extract of the western North American lichen Niebla homalea. The structures of the new and known compounds were established by spectroscopic methods including nuclear magnetic resonance spectroscopy, mass spectrometry and electronic circular dichroism. Among the compounds isolated, usnic acid exhibited moderately potent antiproliferative activities against the A2780 ovarian (IC50 3.8 µM) and MCF-7 breast cancer (IC50 6.8 µM) cell lines. A plausible mode of formation of the chlorine-containing compound nieblastictane C is provided and the contribution of the isolated compounds to the chemotaxonomy of United States lichen species of the genus Niebla is also discussed.


Assuntos
Ascomicetos , Líquens , Neoplasias Ovarianas , Linhagem Celular Tumoral , Feminino , Humanos , Espectroscopia de Ressonância Magnética , Estados Unidos
14.
Yakugaku Zasshi ; 140(10): 1251-1258, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-32999204

RESUMO

Natural materials such as crude drugs and foods are mixtures composed of various metabolites. Metabolic profiling is often used to identify possible correlations between a compound's metabolic profile and pharmacologic activity. Direct-injection electron ionization-mass spectrometry (DI-EI-MS) is a novel metabolomics method useful for characterizing biological materials. This review demonstrates the establishment of a DI-EI-MS method for metabolic profiling using several closely related lichen species: Cladonia krempelhuberi, C. gracilis, C. pseudogymnopoda, and C. ramulosa. The qualitative DI-EI-MS method was used to profile major and/or minor constituents in extracts of lichen samples. Each lichen sample could be distinguished by altering the DI-EI-MS electron energy and examining the resulting data using one-way analysis of variance. We also attempted to predict pharmacologic activity using DI-EI-MS metabolomics. Blueberry leaf extracts inhibited the proliferation of adult T-cell leukemia (ATL) cells. Blueberry leaf extracts could be distinguished by principal component analysis based on the absolute intensity of characteristic fragment ions. Twenty cultivars were categorized into four species, and the most appropriate discriminative marker m/z value for identifying each cultivar was selected statistically. Components extracted based on DI-EI-MS analyses could be used to construct a model to predict ATL cell bioactivity. These data suggest that the novel DI-EI-MS metabolomics method is suitable for identifying species of natural materials and predicting their pharmacologic activity. This approach could enhance public health by facilitating evaluations of pharmacologic activity and functionality, leading to the elimination of counterfeit products.


Assuntos
Produtos Biológicos/metabolismo , Produtos Biológicos/farmacologia , Mirtilos Azuis (Planta)/química , Mirtilos Azuis (Planta)/metabolismo , Líquens/metabolismo , Metabolômica , Extratos Vegetais/farmacologia , Proliferação de Células/efeitos dos fármacos , Previsões , Humanos , Leucemia-Linfoma de Células T do Adulto/patologia , Espectrometria de Massas/métodos , Metabolômica/métodos , Extratos Vegetais/isolamento & purificação
15.
Environ Monit Assess ; 192(11): 693, 2020 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-33037947

RESUMO

The subject of this paper is the possibility of using self-organizing map (SOM) in the biomonitoring studies. We used lichens as biomonitors to indicate different degrees of air quality. This research included all of 88 lichen species that was collected at 75 investigated points. These lichen species showed the different responses to air pollution. The air quality was assessed by IAP (index of atmospheric pollution) values. The IAP values were calculated for all of investigated points on the territory of four natural and one urban ecosystem. Calculated IAP values were in range of 10 to 75. On the basis of the lichen data and IAP values, we have employed SOM analysis that distinguished three clusters (A, B, and C). It presented lichen indicator species for each cluster: 16 species for cluster A, 18 species for cluster B, and two species for cluster C. This paper presents a useful method to find indicator species.


Assuntos
Poluição do Ar , Líquens , Península Balcânica , Ecossistema , Monitoramento Ambiental , Sérvia
16.
Oecologia ; 194(4): 757-770, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33129203

RESUMO

Current strategies for conservation reportedly suffer from an inadequate awareness of the drivers affecting lichen diversity, pointing to the need to fully develop a functional approach to lichen ecology. This study is an attempt to detect the drivers affecting functional diversity in the lichen flora of a volcanic Mediterranean area. Data on epiphytic lichen distribution were correlated with information coming from a GIS analysis. Species richness, functional diversity and indicator values of lichens species were analyzed as a function of altitude, bioclimatic patterns and land use patterns. Both taxonomic and functional diversity were found to increase with altitude, peaking at 600 m a.s.l. and slightly decreasing at higher elevations. A filtering effect of altitude on lichen growth-forms was detected at increasing altitude, with foliose isidiate lichens replacing crustose lichens with sexual reproduction, cyanobacteria replacing Trentepohlia as photobiont, and oligotrophic species linked to partially shaded environments gradually replacing species indicating eutrophic conditions. Forest stations impacted by low impact traditional agriculture tended to express higher lichen diversity compared to either undisturbed broadleaved forests or intensive orchards. These data demonstrate the need to integrate traditional low-impact agricultural practices in protected areas. Moreover, they provide the evidence that reanalyzing past and recent lichenological censuses with the proposed analytical tools may help previewing and driving the evolution of endangered ecosystems.


Assuntos
Líquens , Biodiversidade , Ecossistema , Monitoramento Ambiental , Florestas , Itália
17.
BMC Ecol ; 20(1): 56, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-33059667

RESUMO

BACKGROUND: Landscape genetics is an interdisciplinary field that combines tools and techniques from population genetics with the spatially explicit principles from landscape ecology. Spatial variation in genotypes is used to test hypotheses about how landscape pattern affects dispersal in a wide range of taxa. Lichens, symbiotic associations between mycobionts and photobionts, are an entity for which little is known about their dispersal mechanism. Our objective was to infer the dispersal mechanism in the semi-aquatic lichen Dermatocarpon luridum using spatial models and the spatial variation of the photobiont, Diplosphaera chodatii. We sequenced the ITS rDNA and the ß-actin gene regions of the photobiont and mapped the haplotype spatial distribution in Payuk Lake. We subdivided Payuk Lake into subpopulations and applied four spatial models based on the topography and hydrology to infer the dispersal mechanism. RESULTS: Genetic variation corresponded with the topography of the lake and the net flow of water through the waterbody. A lack of isolation-by-distance suggests high gene flow or dispersal within the lake. We infer the dispersal mechanism in D. luridum could either be by wind and/or water based on the haplotype spatial distribution of its photobiont using the ITS rDNA and ß-actin markers. CONCLUSIONS: We inferred that the dispersal mechanism could be either wind and/or water dispersed due to the conflicting interpretations of our landscape hypotheses. This is the first study to use spatial modelling to infer dispersal in semi-aquatic lichens. The results of this study may help to understand lichen dispersal within aquatic landscapes, which can have implications in the conservation of rare or threatened lichens.


Assuntos
Líquens , Fluxo Gênico , Genética Populacional , Genótipo , Líquens/genética , Simbiose
18.
BMC Evol Biol ; 20(1): 115, 2020 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-32912146

RESUMO

BACKGROUND: In this study, we investigate species limits in the cyanobacterial lichen genus Rostania (Collemataceae, Peltigerales, Lecanoromycetes). Four molecular markers (mtSSU rDNA, ß-tubulin, MCM7, RPB2) were sequenced and analysed with two coalescent-based species delimitation methods: the Generalized Mixed Yule Coalescent model (GMYC) and a Bayesian species delimitation method (BPP) using a multispecies coalescence model (MSC), the latter with or without an a priori defined guide tree. RESULTS: Species delimitation analyses indicate the presence of eight strongly supported candidate species. Conclusive correlation between morphological/ecological characters and genetic delimitation could be found for six of these. Of the two additional candidate species, one is represented by a single sterile specimen and the other currently lacks morphological or ecological supporting evidence. CONCLUSIONS: We conclude that Rostania includes a minimum of six species: R. ceranisca, R. multipunctata, R. occultata 1, R. occultata 2, R. occultata 3, and R. occultata 4,5,6. Three distinct Nostoc morphotypes occur in Rostania, and there is substantial correlation between these morphotypes and Rostania thallus morphology.


Assuntos
Ascomicetos/classificação , Especiação Genética , Líquens/microbiologia , Filogenia , Teorema de Bayes , DNA Ribossômico/genética , Marcadores Genéticos , Modelos Genéticos , Especificidade da Espécie
19.
PLoS One ; 15(9): e0238303, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32997661

RESUMO

Lichens are stable symbiotic associations between fungus and algae and/or cyanobacteria that have different biological activities. Around 60% of anti-cancer drugs are derived from natural resources including plants, fungi, sea creatures, and lichens. This project aims to identify the apoptotic effects and proliferative properties of extracts of Bryoria capillaris (Ach.) Brodo & D.Hawksw, Cladonia fimbriata (L.) Fr., Evernia divaricata (L.) Ach., Hypogymnia tubulosa (Schaer.) Hav., Lobaria pulmonaria (L.) Hoffm., and Usnea florida (L.) Weber ex Wigg. lichen species on prostate cancer cells. Lichen extracts were performed by ethanol, methanol, and acetone separately by using the Soxhlet apparatus and the effects of the extracts on cell viability, proliferation, and apoptosis were measured with the utilization of MTT, LDH assay, Annexin V assay, and Western Blot. Findings of our study revealed a positive correlation between the elevation of cell sensitivity and the increase in the treatment doses of the extract in that higher doses applied reverberate to higher cell sensitivity. A similar correlation was also identified between cell sensitivity elevation and the duration of the treatment. Evidence in our study have shown the existence of an anti-proliferative effect in the extracts of Bryoria capillaris, Evernia divaricata (L.) Ach., Hypogymnia tubulosa (Schaer.) Hav., Lobaria pulmonaria (L.) Hoffm., and Usnea florida (L.) Weber ex Wigg., while a similar effect was not observed in the extracts of Cladonia fimbriata. Evernia divaricata induced anti-proliferative and apoptotic effects in PC-3 cells, which induced apoptotic cell death by both extrinsic and intrinsic pathways. Hypogymnia tubulosa has been shown to have anti-proliferative and apoptotic effects in all extractions methods and our findings identified that both the percentage of the apoptotic cells and apoptotic protein expressions recorded an increase at lower treatment concentrations. Although Lobaria pulmonaria is known to have significant cytotoxic effects, we did not observe a decrease in cell proliferation. Indeed, proliferation marker proliferating cell nuclear antigen (PCNA) protein expression levels have shown an increase in all extracts, while Usnea florida exhibited apoptosis induction and slight proliferation reduction in extract treatments with lower concentrations. We tested 18 extracts of six lichen species during our study. Of these, Evernia divaricata and Hypogymnia tubulosa demonstrated significant apoptotic activity on prostate cancer cells including at low concentrations, which implies that it is worth pursuing the biologically active lead compounds of these extracts on prostate cancer in vitro. Further corroboratory studies are needed to validate the relative potential of these extracts as anti-metastatic and anti-tumorigenic agents.


Assuntos
Antineoplásicos/farmacologia , Apoptose , Proliferação de Células , Líquens/química , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia , Humanos , Masculino , Células Tumorais Cultivadas
20.
Proc Natl Acad Sci U S A ; 117(38): 23847-23858, 2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32873646

RESUMO

Umbilicaria muhlenbergii is the only known dimorphic lichenized fungus that grows in the hyphal form in lichen thalli but as yeast cells in axenic cultures. However, the regulation of yeast-to-hypha transition and its relationship to the establishment of symbiosis are not clear. In this study, we show that nutrient limitation and hyperosmotic stress trigger the dimorphic change in U. muhlenbergii Contact with algal cells of its photobiont Trebouxia jamesii induced pseudohyphal growth. Treatments with the cAMP diphosphoesterase inhibitor IBMX (3-isobutyl-1-methylxanthine) induced pseudohyphal/hyphal growth and resulted in the differentiation of heavily melanized, lichen cortex-like structures in culture, indicating the role of cAMP signaling in regulating dimorphism. To confirm this observation, we identified and characterized two Gα subunits UmGPA2 and UmGPA3 Whereas deletion of UmGPA2 had only a minor effect on pseudohyphal growth, the ΔUmgpa3 mutant was defective in yeast-to-pseudohypha transition induced by hyperosmotic stress or T. jamesii cells. IBMX treatment suppressed the defect of ΔUmgpa3 in pseudohyphal growth. Transformants expressing the UmGPA3 G45V or UmGPA3 Q208L dominant active allele were enhanced in the yeast-to-pseudohypha transition and developed pseudohyphae under conditions noninducible to the wild type. Interestingly, T. jamesii cells in close contact with pseudohyphae of UmGPA3 G45V and UmGPA3 Q208L transformants often collapsed and died after coincubation for over 72 h, indicating that improperly regulated pseudohyphal growth due to dominant active mutations may disrupt the initial establishment of symbiotic interaction between the photobiont and mycobiont. Taken together, these results show that the cAMP-PKA pathway plays a critical role in regulating dimorphism and symbiosis in U. muhlenbergii.


Assuntos
Ascomicetos , AMP Cíclico/metabolismo , Líquens , Simbiose/fisiologia , Clorófitas/metabolismo , Clorófitas/fisiologia , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Hifas/citologia , Hifas/metabolismo , Transdução de Sinais/fisiologia
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