RESUMEN
Nothofagus antarctica (G.Forst.) Oerst. (Ñire) leaves are a valuable source of (poly)phenolic compounds and represent a high-value non-timber product from Patagonian forests. However, information on the variability of their chemical profile is limited or non-existent. The aim of this study was to evaluate the (poly)phenolic variability in Ñire leaf infusions. To this end, different tree populations growing under different temperature regimes and soil characteristics were considered. Interestingly, a cup of Ñire leaf infusion could be considered as a rich source of quercetin. Significant differences in the (poly)phenolic content, especially in flavonoid conjugates and cinnamic acids, were found among the populations studied. These results suggest metabolic variability among the forests studied, which could be related to the species response to its growing conditions, and also provide some clues about the performance of N. antarctica under future climate scenarios. The N. antarctica forests growing in environments with lower frequency of cold and heat stress and high soil fertility showed better infusion quality. This study showed how a South American beech interacts with its local environment at the level of secondary metabolism. In addition, the information obtained is useful for defining forest management strategies in the Patagonian region.
Asunto(s)
Fagus , Hojas de la Planta , Hojas de la Planta/metabolismo , Hojas de la Planta/química , Fagus/metabolismo , Fagus/crecimiento & desarrollo , Suelo/química , Bosques , Temperatura , Fenoles/análisis , Fenoles/metabolismo , Flavonoides/análisis , Flavonoides/metabolismoRESUMEN
PREMISE: Functional traits reflect species' responses to environmental variation and the breadth of their ecological niches. Fagus grandifolia and Oreomunnea mexicana have restricted distribution in upper montane cloud forests (1700-2000 m a.s.l.) in Mexico. These species were introduced into plantings at lower elevations (1200-1600 m a.s.l.) that have climates predicted for montane forests in 2050 and 2070. The aim was to relate morphological leaf traits to the ecological niche structure of each species. METHODS: Leaf functional traits (leaf area, specific leaf area [SLA], thickness, and toughness) were analyzed in forests and plantings. Atmospheric circulation models and representative concentration pathways (RCPs: 2.6, 4.5, 8.5) were used to assess future climate conditions. Trait-niche relationships were analyzed by measuring the Mahalanobis distance (MD) from the forests and the plantings to the ecological niche centroid (ENC). RESULTS: For both species, leaf area and SLA were higher and toughness lower in plantings at lower elevation relative to those in higher-elevation forests, and thickness was similar. Leaf traits varied with distance from sites to the ENC. Forests and plantings have different environmental locations regarding the ENC, but forests are closer (MD 0.34-0.58) than plantings (MD 0.50-0.70) for both species. CONCLUSIONS: Elevation as a proxy for expected future climate conditions influenced the functional traits of both species, and trait patterns related to the structure of their ecological niches were consistent. The use of distances to the ENC is a promising approach to explore variability in species' functional traits and phenotypic responses in optimal versus marginal environmental conditions.
Asunto(s)
Cambio Climático , Fagus , Bosques , Hojas de la Planta , Hojas de la Planta/fisiología , Hojas de la Planta/anatomía & histología , Fagus/fisiología , Fagus/anatomía & histología , México , EcosistemaRESUMEN
Four novel seconeodolastane diterpenoids, named tricholomalides D-G, were isolated, together with the known tricholomalide C, from the fruiting bodies of Tricholoma ustaloides Romagn., a species belonging to the large Tricholoma genus of higher mushrooms (Basidiomycota, family Tricholomataceae). They were isolated through multiple chromatographic separations, and the structures, including the absolute configuration, were established through a detailed analysis of MS, NMR, and CD spectral data and comparison with related compounds reported in the literature, which has been thoroughly revised.
Asunto(s)
Fagus , Tricholoma , Madera , Tricholoma/química , Espectroscopía de Resonancia MagnéticaRESUMEN
The secondary metabolites produced by Tricholoma ustaloides Romagn., a mushroom species belonging to the large Tricholoma genus (Basidiomycota, Tricholomataceae), are unknown. Therefore, encouraged by the interesting results obtained in our previous chemical analyses of a few Tricholoma species collected in Italian woods, we aimed to investigate the secondary metabolites of Tricholoma ustaloides. The chemical analysis involved the isolation and characterization of secondary metabolites through an extensive chromatographic study. The structures of isolated metabolites, including the absolute configuration, were established based on a detailed analysis of MS, NMR spectroscopic, optical rotation, and circular dicroism data, and on comparison with those of related compounds reported in the literature. Two novel lanostane triterpenoids, named tricholidic acids B and C, together with triglycerides, a mixture of free fatty acids, five unidentified metabolites, and the known rare saponaceolides F and J, tricholidic acid, and tricholomenyn C, were isolated from an EtOAc extract of fruiting bodies of Tricholoma ustaloides that were collected in an Italian beech wood. This is the second example of isolation of tricholidic acid derivatives from a natural source. Saponaceolides F and J exhibited high cytotoxicity (IC50 values ≤ 10 µM) against a panel of five human cancer cell lines. The toxicity against myeloid leukemia (HL-60), lung cancer (A-549), hepatocellular cancer (HepG2), renal cancer (Caki-1), and breast cancer (MCF-7) cells was higher than that shown by the very well-known cytotoxic drug cisplatin.
Asunto(s)
Fagus , Tricholoma , Triterpenos , Humanos , Triterpenos/química , Estructura Molecular , Madera , Tricholoma/química , Células HL-60 , Cuerpos Fructíferos de los Hongos/químicaRESUMEN
Introduction: Wood is a natural resource used for construction and the manufacture of many products. This material is exposed to damage due to biotic and abiotic factors. An important biotic factor is wood-degrading fungi that generate large economic losses. The objectives of this study were to determine the effect of xylophagous fungi (Coniophora puteana and Trametes versicolor) on the natural durability of six timber species in southern Durango, Mexico, and to establish differences between fungal effects on each tree species. Materials and Methods: Samples of Pinus durangensis, P. cooperi, P. strobiformis, Juniperus deppeana, Quercus sideroxyla, and Alnus acuminata were exposed to fungi for 4 months under laboratory conditions according to European Standard EN350-1. Samples of Fagus sylvatica were used as control. Durability was determined as the percentage of wood mass loss for each species. Welch ANOVA tests were performed to establish differences among tree species. Welch t-tests were used to prove loss mass differences between fungi for each tree species. Results: The most resistant species to C. puteana were P. durangensis, J. deppeana, P. cooperi and P. strobiformis, showing mean mass losses lower than 8.08%. The most resistant species to T. versicolor were J. deppeana, P. strobiformis and P. durangensis (mean mass losses lower than 7.39%). Pinus strobiformis and Q. sideroxyla were more susceptible to C. puteana effect; in contrast, P. durangensis and P. cooperi showed more damage due to T. versicolor degradation. Conclusions: Woods of P. durangensis, P. cooperi, P. strobiformis and Juniperus deppeana are well adapted to infection by these xylophagous fungi and are therefore highly recommended for commercial use in southern Durango, Mexico.
Asunto(s)
Fagus , Pinus , Trametes/metabolismo , México , Madera/metabolismo , Pinus/metabolismo , Fagus/microbiologíaRESUMEN
Fag s 1 is a member of the Pathogen Related protein family 10 (PR-10) and can elicit cross-reaction with IgE antibodies produced against the birch pollen allergen Bet v 1. The Nuclear Magnetic Resonance (NMR) structure of Fag s 1 is presented along with its dynamic properties. It shares 66% identity with Bet v 1 and exhibits the expected three α-helices and seven ß-sheets arranged as a semi-beta barrel and exposing the residues mapped as the Bet v 1 IgE epitope. The structural dynamics of Fag s 1 were monitored on the fast and intermediate timescales, using relaxation rates. The complex dynamics of Fag s 1 are closely related to the internal cavity, and they modulate IgE and ligand binding.
Asunto(s)
Alérgenos/inmunología , Antígenos de Plantas/química , Reacciones Cruzadas , Fagus/inmunología , Proteínas de Plantas/química , Antígenos de Plantas/inmunología , Antígenos de Plantas/aislamiento & purificación , Betula/inmunología , Epítopos/inmunología , Humanos , Simulación de Dinámica Molecular , Resonancia Magnética Nuclear Biomolecular , Proteínas de Plantas/inmunología , Proteínas de Plantas/aislamiento & purificación , Polen/inmunología , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/aislamiento & purificación , Relación Estructura-ActividadRESUMEN
Xylanases (EC 3.2.1.8) are hydrolytic enzymes, which randomly cleave the ß-1,4-linked xylose residues from xylan. The synthetic gene xynBS27 from Streptomyces sp. S27 was successfully cloned and expressed in Pichia pastoris. The full-length gene consists of 729 bp and encodes 243 amino acids including 51 residues of a putative signal peptide. This enzyme was purified in two steps and was shown to have a molecular weight of 20 kDa. The purified r-XynBS27 was active against beechwood xylan and oat spelt xylan as expected for GH 11 family. The optimum pH and temperature values for the enzyme were 6.0 and 75 °C, respectively. The Km and Vmax were 12.38 mg/mL and 13.68 µmol min/mg, respectively. The r-XynBS27 showed high xylose tolerance and was inhibited by some metal ions and by SDS. r-XynBS27 was employed as an additive in the bread making process. A decrease in firmness, stiffness and consistency, and improvements in specific volume and reducing sugar content were recorded.
Asunto(s)
Proteínas Bacterianas/metabolismo , Pan , Clonación Molecular , Endo-1,4-beta Xilanasas/metabolismo , Pichia/genética , Avena , Proteínas Bacterianas/genética , Proteínas Bacterianas/aislamiento & purificación , Pan/análisis , Electroforesis en Gel de Poliacrilamida , Endo-1,4-beta Xilanasas/genética , Endo-1,4-beta Xilanasas/aislamiento & purificación , Estabilidad de Enzimas , Escherichia coli , Fagus , Calidad de los Alimentos , Concentración de Iones de Hidrógeno , Pichia/metabolismo , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Streptomyces/enzimología , Streptomyces/genética , Temperatura , Xilanos/metabolismoRESUMEN
This study explores the biotechnological potential for plant production of twelve psychrotolerant yeasts strains from Northwest-Patagonia. These strains were isolated from different substrates associated with Nothofagus sp. in native forests and Vaccinium sp. in a commercial plantation. Yeasts characterization was performed using in vitro assays to evaluate the production of auxin-like compounds and siderophores, ability to solubilize inorganic phosphate and to reduce common plant pathogen growth. Strain YF8.3 identified as Aureobasidium pullullans was the main producer of auxin-like and siderophores compounds. Phosphate solubilization was a characteristic observed by strains L8.12 and CRUB1775 identified as Holtermaniella takashimae and Candida maritima, respectively. Different yeast strains were able to inhibit the growth of Verticillium dahliae PPRI5569 and Pythium aphanidermatum PPRI 9009, but they all failed to inhibit the growth of Fusarium oxysporum PPRI5457. The present study, suggests that yeasts present in different environments in Northwestern-Patagonian have physiological in vitro features which may influence plant growth. These results are promising for the developing of biological products based on Patagonian yeasts for plant production in cold-temperate regions.
Asunto(s)
Basidiomycota/metabolismo , Candida/metabolismo , Fagus/microbiología , Fusarium/crecimiento & desarrollo , Pythium/crecimiento & desarrollo , Saccharomycetales/metabolismo , Vaccinium/microbiología , Verticillium/crecimiento & desarrollo , Argentina , Basidiomycota/aislamiento & purificación , Agentes de Control Biológico , Candida/aislamiento & purificación , Ácidos Indolacéticos/metabolismo , Saccharomycetales/aislamiento & purificación , Sideróforos/metabolismo , Microbiología del SueloRESUMEN
Herpes simplex virus belongs to Herpesviridae family and causes infection of humans from ancient times. 4OMe-glucuronoxylans as the renewable biopolymers can be promising glycomaterials for various applications in pharmacy. Control enzymatic degradation of the native 4OMe-glucuronoxylan (GX1) followed by targeted sulfation procedure afforded a range of 4OMe-glucuronoxylan sulfates differed in the degree of sulfation (10-16%) and molecular mass (21,000-5000g/mol; GXS1>GXS2>GXS3>GXS4). Antiviral activity tests on GXS1-4 against herpes simplex virus (HSV) types 1 and 2 revealed the positive effect of all compounds against strains of herpes virus. Of them, the compounds GXS1 and GXS4 were shown to be the most active for both HSV serotypes. The antiviral activity of GXS1 and GXS4 was similar to those of heparin or dextran sulfate, used as reference compounds. It was found that GXS1 and GXS4 were active as well against Polio and dengue viruses, however, on a smaller scale. The mode of antiviral action of 4OMe-glucuronoxylan sulfates is due to inhibition of the virus binding to the cell receptors.
Asunto(s)
Antivirales/química , Antivirales/farmacología , Fagus/química , Sulfatos/química , Xilanos/química , Xilanos/farmacología , Animales , Antivirales/toxicidad , Chlorocebus aethiops , Células Vero , Virus/efectos de los fármacos , Xilanos/toxicidadRESUMEN
Fagales allergens belonging to the Bet v 1 family account responsible for the majority of spring pollinosis in the temperate climate zones in the Northern hemisphere. Among them, Fag s 1 from beech pollen is an important trigger of Fagales pollen associated allergic reactions. The protein shares high similarity with birch pollen Bet v 1, the best-characterized member of this allergen family. Of note, recent work on Bet v 1 and its homologues found in Fagales pollen demonstrated that not all allergenic members of this family have the capacity to induce allergic sensitization. Fag s 1 was shown to bind pre-existing IgE antibodies most likely primarily directed against other members of this multi-allergen family. Therefore, it is especially interesting to compare the structures of Bet v 1-like pollen allergens, which have the potential to induce allergic sensitization with allergens that are mainly cross-reactive. This in the end will help to identify allergy eliciting molecular pattern on Bet v 1-like allergens. In this work, we report the (1)H, (15)N and (13)C NMR assignment of beech pollen Fag s 1 as well as the secondary structure information based on backbone chemical shifts.
Asunto(s)
Alérgenos/química , Fagus/química , Resonancia Magnética Nuclear Biomolecular , Proteínas de Plantas/química , Isótopos de Carbono , Isótopos de Nitrógeno , Estructura Secundaria de Proteína , TritioRESUMEN
Diameter at breast height (DBH) is the simplest, most common and most important tree dimension in forest inventory and is closely correlated with wood volume, height and biomass. In this study, a number of linear and nonlinear models predicting diameter at breast height from stump diameter were developed and evaluated for Oriental beech (Fagus orientalisLipsky) stands located in the forest region of Ayanck, in the northeast of Turkey. A set of 1,501 pairs of diameter at breast height-stump measurements, originating from 70 sample plots of even-aged Oriental beech stands, were used in this study. About 80 % of the otal data (1,160 trees in 55 sample plots) was used to fit a number of linear and nonlinear model parameters; the remaining 341 trees in 15 sample plots were randomly reserved for model validation and calibration response. The power model data set was found to produce the most satisfactory fits with the Adjusted Coefficient of Determination, R2adj (0.990), Root Mean Square Error, RMSE (1.25), Akaikes Information Criterion, AIC (3820.5), Schwarzs Bayesian Information Criterion, BIC (3837.2), and Absolute Bias (1.25). The nonlinear mixed-effect modeling approach for power model with R2adj(0.993), AIC (3598), BIC (3610.1), Absolute Bias (0.73) and RMSE (1.04) provided much better fitting and precise predictions for DBH from stump diameter than the conventional nonlinear fixed effect model structures for this model. The calibration response including tree DBH and stump diameter measurements of the four largest trees in a calibrated sample plot in calibration produced the highest Bias, -5.31 %, and RMSE, -6.30 %, the greatest reduction percentage.
Asunto(s)
Dinámicas no Lineales , Fagus/anatomía & histología , Modelos LinealesRESUMEN
Diameter at breast height (DBH) is the simplest, most common and most important tree dimension in forest inventory and is closely correlated with wood volume, height and biomass. In this study, a number of linear and nonlinear models predicting diameter at breast height from stump diameter were developed and evaluated for Oriental beech (Fagus orientalisLipsky) stands located in the forest region of Ayanck, in the northeast of Turkey. A set of 1,501 pairs of diameter at breast height-stump measurements, originating from 70 sample plots of even-aged Oriental beech stands, were used in this study. About 80 % of the otal data (1,160 trees in 55 sample plots) was used to fit a number of linear and nonlinear model parameters; the remaining 341 trees in 15 sample plots were randomly reserved for model validation and calibration response. The power model data set was found to produce the most satisfactory fits with the Adjusted Coefficient of Determination, R2adj (0.990), Root Mean Square Error, RMSE (1.25), Akaikes Information Criterion, AIC (3820.5), Schwarzs Bayesian Information Criterion, BIC (3837.2), and Absolute Bias (1.25). The nonlinear mixed-effect modeling approach for power model with R2adj(0.993), AIC (3598), BIC (3610.1), Absolute Bias (0.73) and RMSE (1.04) provided much better fitting and precise predictions for DBH from stump diameter than the conventional nonlinear fixed effect model structures for this model. The calibration response including tree DBH and stump diameter measurements of the four largest trees in a calibrated sample plot in calibration produced the highest Bias, -5.31 %, and RMSE, -6.30 %, the greatest reduction percentage.(AU)
Asunto(s)
Modelos Lineales , Dinámicas no Lineales , Fagus/anatomía & histologíaRESUMEN
Changes in intrinsic water use efficiency (iWUE) were investigated in Fagus sylvatica and Nothofagus spp. over the last century. We combined dendrochronological methods with dual-isotope analysis to investigate whether atmospheric changes enhanced iWUE of Fagus and Nothofagus and tree growth (basal area increment, BAI) along latitudinal gradients in Italy and Chile. Post-maturation phases of the trees presented different patterns in δ13C, Δ13C, δ18O, Ci (internal CO2 concentration), iWUE, and BAI. A continuous enhancement in isotope-derived iWUE was observed throughout the twentieth century, which was common to all sites and related to changes in Ca (ambient CO2 concentration) and secondarily to increases in temperature. In contrast to other studies, we observed a general increasing trend of BAI, with the exception of F. sylvatica in Aspromonte. Both iWUE and BAI were uncoupled with the estimated drought index, which is in agreement with the absence of enduring decline in tree growth. In general, δ13C and δ18O showed a weak relationship, suggesting the major influence of photosynthetic rate on Ci and δ13C, and the minor contribution of the regulation of stomatal conductance to iWUE. The substantial warming observed during the twentieth century did not result in a clear pattern of increased drought stress along these latitudinal transects, because of the variability in temporal trends of precipitation and in specific responses of populations.
Asunto(s)
Fagus/metabolismo , Agua/metabolismo , Carbono/química , Carbono/metabolismo , Dióxido de Carbono/análisis , Isótopos de Carbono/química , Chile , Clima , Sequías , Fagus/crecimiento & desarrollo , Italia , Isótopos de Oxígeno/química , Fotosíntesis , Análisis de Regresión , TemperaturaRESUMEN
Montane forests provide the natural framework to test for various ecological settings at distinct elevations as they may affect population demography, which in turn will affect the spatial genetic structure (SGS). We analyzed the fine-scale SGS of Nothofagus pumilio, which dominates mountain areas of Patagonia, in three pairs of sites at contrasting elevations (low- vs. high-elevation). Within a total area of 1 ha fresh leaf tissue from 90 individuals was collected at each of the six studied stands following a spatially explicit sampling design. Population genetic diversity parameters were analyzed for all sampled individuals using five polymorphic isozyme loci, and a subset of 50 individuals per stand were also screened for five microsatellite loci. The SGS was assessed on 50 individuals/stand, using the combined datasets of isozymes and microsatellites. Most low-elevation stands consisted of older individuals with complex age structures and genetically diverse plots. In contrast, high-elevation stands and one post-fire low-elevation population yielded even-aged structures with evidence of growth suppression, and were genetically homogeneous. All stands yielded significant SGS. Similarly to mature stands of the non-sprouter congener Nothofagus dombeyi, multi-age low-altitude N. pumilio yielded significant SGS weakened by competing species of the understory and the formation of seedling banks. Alike the sprouter Nothofagus antarctica, high-altitude stands produced significant SGS as a consequence of occasional seedling establishment reinforced by vegetative spread.
Asunto(s)
Altitud , ADN de Plantas/genética , Fagus/genética , Repeticiones de Microsatélite/genética , Argentina , Ecosistema , Especiación Genética , Isoenzimas/genética , Polimorfismo Genético , Población/genéticaRESUMEN
Historical climate changes and orogenesis are two important factors that have shaped intraspecific biodiversity patterns worldwide. Although southern South America has experienced such complex events, there is a paucity of studies examining the effects on intraspecific diversification in this part of the world. Liolaemus pictus is the southernmost distributed lizard in the Chilean temperate forest, whose genetic structure has likely been influenced by Pleistocene glaciations. We conducted a phylogeographic study of L. pictus in Chile and Argentina based on one mitochondrial and two nuclear genes recovering two strongly divergent groups, Northern and Southern clades. The first group is distributed from the northernmost limit of the species to the Araucanía region while the second group is distributed throughout the Andes and the Chiloé archipelago in Southern Chile. Our results suggest that L. pictus originated 751 Kya, with divergence between the two clades occurring in the late Pleistocene. Demographic reconstructions for the Northern and Southern clades indicate a decrease in effective population sizes likely associated with Pleistocene glaciations. Surprisingly, patterns of genetic variation, clades age and historical gene flow in populations distributed within the limits of the Last Glacial Maximum (LGM) are not explained by recent colonization. We propose an "intra-Andean multiple refuge" hypothesis, along with the classical refuge hypothesis previously proposed for the biota of the Chilean Coastal range and Eastern Andean Cordillera. Our hypothesis is supported by niche modelling analysis suggesting the persistence of fragments of suitable habitat for the species within the limits of the LGM ice shield. This type of refuge hypothesis is proposed for the first time for an ectothermic species.
Asunto(s)
Cambio Climático , Evolución Molecular , Fagus , Lagartos/genética , Árboles , Animales , Chile , Grupo Citocromo b/genética , ADN Mitocondrial , Ecosistema , Haplotipos , Lagartos/clasificación , Filogenia , FilogeografíaAsunto(s)
Ascomicetos/citología , Ascomicetos/clasificación , Fagus/microbiología , Árboles , Argentina , Chile , Ecosistema , HongosRESUMEN
BACKGROUND: Nothofagus nervosa is one of the most emblematic native tree species of Patagonian temperate forests. Here, the shotgun RNA-sequencing (RNA-Seq) of the transcriptome of N. nervosa, including de novo assembly, functional annotation, and in silico discovery of potential molecular markers to support population and associations genetic studies, are described. RESULTS: Pyrosequencing of a young leaf cDNA library generated a total of 111,814 high quality reads, with an average length of 447 bp. De novo assembly using Newbler resulted into 3,005 tentative isotigs (including alternative transcripts). The non-assembled sequences (singletons) were clustered with CD-HIT-454 to identify natural and artificial duplicates from pyrosequencing reads, leading to 21,881 unique singletons. 15,497 out of 24,886 non-redundant sequences or unigenes, were successfully annotated against a plant protein database. A substantial number of simple sequence repeat markers (SSRs) were discovered in the assembled and annotated sequences. More than 40% of the SSR sequences were inside ORF sequences. To confirm the validity of these predicted markers, a subset of 73 SSRs selected through functional annotation evidences were successfully amplified from six seedlings DNA samples, being 14 polymorphic. CONCLUSIONS: This paper is the first report that shows a highly precise representation of the mRNAs diversity present in young leaves of a native South American tree, N. nervosa, as well as its in silico deduced putative functionality. The reported Nothofagus transcriptome sequences represent a unique resource for genetic studies and provide a tool to discover genes of interest and genetic markers that will greatly aid questions involving evolution, ecology, and conservation using genetic and genomic approaches in the genus.
Asunto(s)
Fagus/genética , Transcriptoma , Argentina , Biblioteca de Genes , Marcadores Genéticos , Repeticiones de Microsatélite , Anotación de Secuencia Molecular , ARN de Planta/genética , Análisis de Secuencia de ADNRESUMEN
A population of Fagus grandifolia var. mexicana (covering ca. 4.7 ha) is established in a montane cloud forest refuge at Acatlan Volcano in eastern Mexico (Veracruz State), and it represents one of only ten populations of this species known to occur in the country (each stand covers ca. 2-35 ha in extension) and one of the southernmost in the continent. Sporocarps of several ectomycorrhizal macrofungi have been observed in the area, and among them, individuals of the genus Lactarius are common in the forest. However, the morphological and molecular characterization of ectomycorrhizae is still in development. Currently, two species of Lactarius have been previously documented in the area. Through the phylogenetic analysis of the internal transcribed spacer (ITS) region from basidiomes and ectomycorrhizae, we identified the Lactarius fumosibrunneus ectomycorrhiza. The host, F. grandifolia var. mexicana, was determined comparing the amplified ITS sequence from ectomycorrhizal root tips in the GenBank database with Basic Local Alignment Search Tool. The mycorrhizal system of L. fumosibrunneus is monopodial-pyramidal, characterized by its shiny, white to silver and pruinose surface, secreting a white latex when damaged, composed of three plectenchymatous mantle layers, with diverticulated terminal elements at the outer mantle. It lacks emanating hyphae, rhizomorphs, and sclerotia. A detailed morphological and anatomical description, illustrations, and photographs of the ectomycorrhiza are presented. The comparison of L. fumosibrunneus and other Lactarius belonging to subgenus Plinthogalus is presented.
Asunto(s)
Basidiomycota/aislamiento & purificación , Fagus/microbiología , Micorrizas/aislamiento & purificación , Secuencia de Bases , Basidiomycota/clasificación , Basidiomycota/citología , Basidiomycota/genética , ADN de Hongos/química , ADN de Hongos/genética , ADN Espaciador Ribosómico/genética , Fagus/citología , Cuerpos Fructíferos de los Hongos , Hifa , México , Datos de Secuencia Molecular , Micorrizas/clasificación , Micorrizas/citología , Micorrizas/genética , Filogenia , Raíces de Plantas/citología , Raíces de Plantas/microbiología , Raíces de Plantas/fisiología , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN , Simbiosis , ÁrbolesRESUMEN
A new milkcap species, Lactarius fuscomarginatus, was found in the subtropical region of central Veracruz (eastern Mexico) associated with two relict populations of Fagus grandifolia var. mexicana. The species is characterized macroscopically by its dark pileus and stipe and by its distant and whitish lamellae with blackish to blackish brown edges. A molecular phylogenetic analyses based on ITS and LSU nucDNA sequences confirms the delimitation of this new taxon and places L. fuscomarginatus in subgenus Gerardii. A detailed morphological comparison is given with similar species.
Asunto(s)
Agaricales/clasificación , Fagus/microbiología , Agaricales/genética , Agaricales/ultraestructura , Secuencia de Bases , ADN de Hongos , ADN Espaciador Ribosómico , México , Datos de Secuencia Molecular , Micorrizas/clasificación , Micorrizas/citología , Filogenia , Análisis de Secuencia de ADN , Esporas Fúngicas/ultraestructura , Árboles/microbiología , Clima TropicalRESUMEN
Ectomycorrhizal (EM) fleshy fungi are being monitored in a population of Fagus grandifolia var. mexicana persisting in a montane cloud forest refuge on a volcano in a subtropical region of central Veracruz (eastern Mexico). The population of Fagus studied represents one of the 10 recognized forest fragments still housing this tree genus in Mexico. This is the first attempt to document EM fungi associated with this tree species in Mexico. We present evidence of the ectomycorrhizal symbiosis for Lactarius badiopallescens and L. cinereus with this endemic tree. Species identification of Lactarius on Fagus grandifolia var. mexicana was based on the comparison of DNAsequences (ITS rDNA) of spatiotemporally co-occurring basidiomes and EM root tips. The host of the EM tips was identified by comparison of the large subunit of the ribulose-bisphosphate carboxylase gene (rbcL). The occurrence of Lactarius badiopallescens and L. cinereus populations in the area of study represent the southernmost record known to date of these two species in North America and are new for the Neotropical Lactarius mycota. Descriptions coupled with illustrations of macro- and micromorphological features of basidiomes as well as photographs of ectomycorrhizas are presented.