RESUMEN
The biogeochemical cycles of trace elements are changed by fire as a result of the mineralization of organic matter. Monitoring the accumulation of trace elements in both the environment and the tree biomass during the post-fire (PF) forest ecosystem regeneration process is important for tree species selection for reforestation in ecosystems under anthropogenic pressure. We analyzed the soil concentrations of different groups of potentially toxic elements (PTEs), including beneficial (Al), toxic (Cd, Cr, Pb), and microelements (Cu, Mn, Ni, Zn), and their bioaccumulation in the tree species (Pinus sylvestris, Betula pendula, Alnus glutinosa) biomass introduced after a fire in a forest weakened by long-term emissions of industrial pollutants. The results indicated no direct threat from the PTEs tested at the PF site. The tree species introduced 30 years ago may have modified the biogeochemical cycles of the PTEs through different strategies of bioaccumulation in the belowground and aboveground biomass. Alder had relatively high Al concentrations in the roots and a low translocation factor (TF). Pine and birch had lower Al concentrations in the roots and higher TFs. Foliage concentrations and the TF of Cd increased from alder to pine to birch. However, the highest concentration and bioaccumulation factor of Cd was found in the alder roots. The concentrations of Cr in the foliage and the Cr TFs in the studied species increased from pine to birch to alder. Higher concentrations of Cu and Ni were found in the foliage of birch and alder than of pine. Among the species, birch also had the highest Pb and Zn concentrations in the roots and foliage. We found that different tree species had different patterns of PTE phytostabilization and ways they incorporated these elements into the biological cycle, and these patterns were not dependent on fire disturbance. This suggests that similar patterns might also occur in more polluted soils. Therefore, species-dependent bioaccumulation patterns could also be used to design phytostabilization and remediation treatments for polluted sites under industrial pressure.
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Monitoreo del Ambiente , Contaminantes del Suelo , Suelo , Árboles , Contaminantes del Suelo/análisis , Contaminantes del Suelo/metabolismo , Suelo/química , Alnus , Betula/metabolismo , Oligoelementos/análisis , Oligoelementos/metabolismo , Incendios , BosquesRESUMEN
The article gives a geobotanical description and a floristic analysis of communities with the participation of the rare and relict species Alnus glutinosa in condition of Aktobe region. The aim of the study is to provide a geobotanical assessment of the current status of a rare, relict species of the Alnus glutinosa population, which was included in the Red Data Book of Kazakhstan. At present, the flora of the Aktobe region is not sufficiently studied. Conservation of the biodiversity of the Aktobe region flora is one of the most topical issues. In Aktobe region, due to the lack of grazing, felling of trees, using as fuel and the emergence of uncontrolled tourism and at the same time due to the lack of natural renewal of the area, these consequences lead to a quantitative reduction in the species. In this regard, it is necessary to study the species and organize protection and conservation measures. The results of the study showed that the plant Alnus glutinosa is rarely found in the flora of Kazakhstan and also the distribution areas are reduced. Of the three investigated points, plants from 24 families were identified. Plant communities of Alnus glutinosa are being studied for the first time in the Aktobe region. For the first time in the conditions of the Aktobe region, the habitat of black alder was discovered. The floral composition of plant communities of Alnus glutinosa grown in various ecological environments was revealed, the ratio of life forms and phytocenotic features were studied for the first time. In addition, alder felt mite and ground bug, damaging black alder, were identified from 3 studied populations. It has been established that the main reason for the spread of this pest is a very strong moistening of the ground on which sticky Alder grows. Results sequencing showed that the DNA sample under study belongs to the fungus Alternaria alternata.
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Alnus , Biodiversidad , Kazajstán , Alnus/clasificaciónRESUMEN
A multitude of anthropogenic stressors impact biological communities and ecosystem processes in urban streams. Prominent among them are salinization, increased temperature, and altered flow regimes, all of which can affect microbial decomposer communities and litter decomposition, a fundamental ecosystem process in streams. Impairments caused by these stressors individually or in combination and recovery of communities and ecosystem processes after release from these stressors are not well understood. To improve our understanding of multiple stressors impacts we performed an outdoor stream mesocosm experiment with 64 experimental units to assess the response of microbial litter decomposers and decomposition. The three stressors we applied in a full-factorial design were increased salinity (NaCl addition, 0.53 mS cm-1 above ambient), elevated temperature (3.5 °C above ambient), and reduced flow velocity (3.5 vs 14.2 cm s-1). After two weeks of stressor exposure (first sampling) and two subsequent weeks of recovery (second sampling), we determined leaf-associated microbial respiration, fungal biomass, and the sporulation activity and community composition of aquatic hyphomycetes in addition to decomposition rates of black alder (Alnus glutinosa) leaves confined in fine-mesh litter bags. Microbial colonization of the litter was accompanied by significant mass loss in all mesocosms. However, there was little indication that mass loss, microbial respiration, fungal biomass, sporulation rate or community composition of aquatic hyphomycetes was strongly affected by either single stressors or their interactions. Two exceptions were temperature effects on sporulation and decomposition rate. Similarly, no notable differences among mesocosms were observed after the recovery phase. These results suggest that microbial decomposers and leaf litter decomposition are either barely impaired by exposure to the tested stressors at the levels applied in our experiment, or that communities in restored urban streams are well adapted to cope with these stressor levels.
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Ríos , Salinidad , Ríos/química , Ríos/microbiología , Biodegradación Ambiental , Ecosistema , Hojas de la Planta , Alnus , Temperatura , Monitoreo del AmbienteRESUMEN
The root nodules of actinorhizal plants are home to nitrogen-fixing bacterial symbionts, known as Frankia, along with a small percentage of other microorganisms. These include fungal endophytes and non-Frankia bacteria. The taxonomic and functional diversity of the microbial consortia within these root nodules is not well understood. In this study, we surveyed and analyzed the cultivable, non-Frankia fungal and bacterial endophytes of root nodules from red and Sitka alder trees that grow together. We examined their taxonomic diversity, co-occurrence, differences between hosts, and potential functional roles. For the first time, we are reporting numerous fungal endophytes of alder root nodules. These include Sporothrix guttuliformis, Fontanospora sp., Cadophora melinii, an unclassified Cadophora, Ilyonectria destructans, an unclassified Gibberella, Nectria ramulariae, an unclassified Trichoderma, Mycosphaerella tassiana, an unclassified Talaromyces, Coniochaeta sp., and Sistotrema brinkmanii. We are also reporting several bacterial genera for the first time: Collimonas, Psychrobacillus, and Phyllobacterium. Additionally, we are reporting the genus Serratia for the second time, with the first report having been recently published in 2023. Pseudomonas was the most frequently isolated bacterial genus and was found to co-inhabit individual nodules with both fungi and bacteria. We found that the communities of fungal endophytes differed by host species, while the communities of bacterial endophytes did not.
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Alnus , Bacterias , Endófitos , Hongos , Nódulos de las Raíces de las Plantas , Endófitos/clasificación , Endófitos/aislamiento & purificación , Endófitos/genética , Alnus/microbiología , Hongos/clasificación , Hongos/aislamiento & purificación , Hongos/genética , Bacterias/clasificación , Bacterias/aislamiento & purificación , Bacterias/genética , Nódulos de las Raíces de las Plantas/microbiología , Biodiversidad , Simbiosis , FilogeniaRESUMEN
The globalization in plant material trading has caused the emergence of invasive pests in many ecosystems, such as the alder pathogen Phytophthora ×alni in European riparian forests. Due to the ecological importance of alder to the functioning of rivers and the increasing incidence of P. ×alni-induced alder decline, effective and accessible decision tools are required to help managers and stakeholders control the disease. This study proposes a Bayesian belief network methodology to integrate diverse information on the factors affecting the survival and infection ability of P. ×alni in riparian habitats to help predict and manage disease incidence. The resulting Alder Decline Network (ADnet) management tool integrates information about alder decline from scientific literature, expert knowledge and empirical data. Expert knowledge was gathered through elicitation techniques that included 19 experts from 12 institutions and 8 countries. An original dataset was created covering 1189 European locations, from which P. ×alni occurrence was modeled based on bioclimatic variables. ADnet uncertainty was evaluated through its sensitivity to changes in states and three scenario analyses. The ADnet tool indicated that mild temperatures and high precipitation are key factors favoring pathogen survival. Flood timing, water velocity, and soil type have the strongest influence on disease incidence. ADnet can support ecosystem management decisions and knowledge transfer to address P. ×alni-induced alder decline at local or regional levels across Europe. Management actions such as avoiding the planting of potentially infected trees or removing man-made structures that increase the flooding period in disease-affected sites could decrease the incidence of alder disease in riparian forests and limit its spread. The coverage of the ADnet tool can be expanded by updating data on the pathogen's occurrence, particularly from its distributional limits. Research on the role of genetic variability in alder susceptibility and pathogen virulence may also help improve future ADnet versions.
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Alnus , Teorema de Bayes , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/estadística & datos numéricos , Phytophthora , Ecosistema , Europa (Continente)/epidemiología , Bosques , Conservación de los Recursos NaturalesRESUMEN
Today, allergies have become a serious problem. PR-10 proteins are clinically relevant allergens that have the ability to bind hydrophobic ligands, which can significantly increase their allergenicity potential. It has been recently shown that not only the birch pollen allergen Bet v 1 but also the alder pollen allergen Aln g 1, might act as a true sensitizer of the immune system. The current investigation is aimed at the further study of the allergenic and structural features of Aln g 1. By using qPCR, we showed that Aln g 1 was able to upregulate alarmins in epithelial cells, playing an important role in sensitization. With the use of CD-spectroscopy and ELISA assays with the sera of allergic patients, we demonstrated that Aln g 1 did not completely restore its structure after thermal denaturation, which led to a decrease in its IgE-binding capacity. Using site-directed mutagenesis, we revealed that the replacement of two residues (Asp27 and Leu30) in the structure of Aln g 1 led to a decrease in its ability to bind to both IgE from sera of allergic patients and lipid ligands. The obtained data open a prospect for the development of hypoallergenic variants of the major alder allergen Aln g 1 for allergen-specific immunotherapy.
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Alérgenos , Antígenos de Plantas , Inmunoglobulina E , Proteínas de Plantas , Polen , Humanos , Polen/inmunología , Polen/química , Alérgenos/inmunología , Alérgenos/química , Antígenos de Plantas/inmunología , Antígenos de Plantas/química , Inmunoglobulina E/inmunología , Proteínas de Plantas/inmunología , Proteínas de Plantas/química , Alnus/inmunología , Alnus/químicaRESUMEN
Alnus glutinosa is an actinorhizal plant that fixes N via actinomycetes. Compared to other trees, A. glutinosa is more resistant to environmental stress and able to uptake soil nutrients more easily. Alnus glutinosa grows well not only in natural stands but also in degraded environment or soil in need of restoration. Changes in the contents of selected macro-, micro-, and non-nutrient elements in the leaves of A. glutinosa during the vegetation season were monitored in the Ore Mountains (Czech Republic), an area affected by extreme air pollution in the past. Decreased foliar content of N, P, K, and Cu, and increased content of Ca, Mn, Zn, and Al were observed; the content of other elements (S, Mg, Pb, and Cd) varied during the growing season or remained constant. From the viewpoint of nutrition, the content of N, S, Ca, and Mg macroelements was adequate; concentrations of P and K were low. Excessive amounts of Mn and Zn were measured, and the level of Cu was good. Non-nutrient elements Pb and Cd were present at the background level, and the level of Al was high. N/P, N/Ca, N/Mg, and Ca/Mg ratios were balanced, S/N value showed the lack of S, and N/K ratio indicated low content of K, which caused also suboptimal K/Ca and K/Mg values. The P/Al ratio varied from balanced to lower values. The content of individual elements and monitored changes were influenced by the amount of elements in the soil, moisture conditions, foliage phenology, and altitude.
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Alnus , Cadmio , Plomo , Estaciones del Año , Monitoreo del Ambiente , SueloRESUMEN
Although the pesticide hexachlorocyclohexane (HCH) and its isomers have long been banned, their presence in the environment is still reported worldwide. In this study, we investigated the bioaccumulation potential of α, ß, and δ hexachlorocyclohexane (HCH) isomers in black alder saplings (Alnus glutinosa) to assess their environmental impact. Each isomer, at a concentration of 50 mg/kg, was individually mixed with soil, and triplicate setups, including a control without HCH, were monitored for three months with access to water. Gas chromatography-mass spectrometry revealed the highest concentrations of HCH isomers in roots, decreasing towards branches and leaves, with δ-HCH exhibiting the highest uptake (roots-14.7 µg/g, trunk-7.2 µg/g, branches-1.53 µg/g, leaves-1.88 µg/g). Interestingly, α-HCH was detected in high concentrations in ß-HCH polluted soil. Phytohormone analysis indicated altered cytokinin, jasmonate, abscisate, and gibberellin levels in A. glutinosa in response to HCH contamination. In addition, amplicon 16S rRNA sequencing was used to study the rhizosphere and soil microbial community. While rhizosphere microbial populations were generally similar in all HCH isomer samples, Pseudomonas spp. decreased across all HCH-amended samples, and Tomentella dominated in ß-HCH and control rhizosphere samples but was lowest in δ-HCH samples.
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Alnus , Contaminantes del Suelo , Hexaclorociclohexano/análisis , Biodegradación Ambiental , ARN Ribosómico 16S/genética , Contaminantes del Suelo/análisis , SueloRESUMEN
Alders are nitrogen (N)-fixing riparian trees that promote leaf litter decomposition in streams through their high-nutrient leaf litter inputs. While alders are widespread across Europe, their populations are at risk due to infection by the oomycete Phytophthora ×alni, which causes alder dieback. Moreover, alder death opens a space for the establishment of an aggressive N-fixing invasive species, the black locust (Robinia pseudoacacia). Shifts from riparian vegetation containing healthy to infected alder and, eventually, alder loss and replacement with black locust may alter the key process of leaf litter decomposition and associated microbial decomposer assemblages. We examined this question in a microcosm experiment comparing three types of leaf litter mixtures: one representing an original riparian forest composed of healthy alder (Alnus lusitanica), ash (Fraxinus angustifolia), and poplar (Populus nigra); one with the same species composition where alder had been infected by P. ×alni; and one where alder had been replaced with black locust. The experiment lasted six weeks, and every two weeks, microbially driven decomposition, fungal biomass, reproduction, and assemblage structure were measured. Decomposition was highest in mixtures with infected alder and lowest in mixtures with black locust, reflecting differences in leaf nutrient concentrations. Mixtures with alder showed distinct fungal assemblages and higher sporulation rates than mixtures with black locust. Our results indicate that alder loss and its replacement with black locust may alter key stream ecosystem processes and assemblages, with important changes already occurring during alder infection. This highlights the importance of maintaining heathy riparian forests to preserve proper stream ecosystem functioning.
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Alnus , Ecosistema , Árboles , Ríos/microbiología , Biomasa , Nitrógeno , Hojas de la Planta/microbiología , Alnus/microbiologíaRESUMEN
Leaf ecophysiological traits are known to change with leaf and tree age. In the present study, we measured the effect of leaf and tree age on leaf ecophysiological and morphological traits of nitrogen-fixing Alnus nepalensis (D. Don) which is a pioneer tree species in degraded lands. Three naturally occurring A. nepalensis forest stands, namely young (5-8 years old), mature (40-55 years old), and old (130-145 years old), were considered in this study. We also investigated the seasonal variations in leaf ecophysiological and morphological traits during leaf flushing, fully expanded, and leaf senescence phenological stages. The ecophysiological and morphological traits were compared between leaf and tree ages using a linear mixed-effect model (LMM) and Tukey's HSD test. Fully expanded leaves and young trees demonstrate ecophysiological traits consistent with acquisitive resource-use strategies. Our results revealed that net photosynthetic capacity (Aarea and Amass), leaf stomatal conductance (gswarea and gswmass), transpiration rate (Earea and Emass), specific leaf area (SLA), predawn and midday water potential (Ψ), leaf total chlorophyll concentration, photosynthetic N- and P-use efficiency (PNUE and PPUE) were higher in younger trees than mature and old trees. We found lower wateruse efficiency (WUE) and intrinsic water-use efficiency (WUEi) in young trees than in mature and old ones. Mass-based net photosynthetic capacity (Amass) was positively correlated with PNUE, PPUE, transpiration rate, stomatal conductance, SLA and chlorophyll concentrations but negatively correlated with WUE and WUEi. However, mass-based leaf nitrogen (N) and phosphorus (P) concentrations were the highest in fully expanded leaves and did not vary with tree age despite N concentration being negatively correlated with SLA. Overall, this study provides valuable insights into the age-related changes in leaf ecophysiological traits of A. nepalensis. The findings underscore the importance of considering tree age when studying plant ecophysiology and highlight the acquisitive resource-use strategies employed by young trees for rapid growth and establishment.
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Alnus , Árboles , Árboles/metabolismo , Alnus/metabolismo , Himalayas , Fotosíntesis , Clorofila/metabolismo , Nitrógeno/metabolismo , Agua , Nutrientes , Hojas de la Planta/metabolismoRESUMEN
The tolerance of European alder (Alnus glutinosa Gaertn.) to soil salinity can be attributed to symbiosis with microorganisms at the absorptive root level. However, it is uncertain how soil salinity impacts microbial recruitment in the following growing season. We describe the bacterial and fungal communities in the rhizosphere and endosphere of A. glutinosa absorptive roots at three tested sites with different salinity level. We determined the morphological diversity of ectomycorrhizal (ECM) fungi, the endophytic microbiota in the rhizosphere, and the colonization of new absorptive roots in the following growing season. While bacterial diversity in the rhizosphere was higher than that in the absorptive root endosphere, the opposite was true for fungi. Actinomycetota, Frankiales, Acidothermus sp. and Streptomyces sp. were more abundant in the endosphere than in the rhizosphere, while Actinomycetota and Acidothermus sp. dominated at saline sites compared to nonsaline sites. Basidiomycota, Thelephorales, Russulales, Helotiales, Cortinarius spp. and Lactarius spp. dominated the endosphere, while Ascomycota, Hypocreales and Giberella spp. dominated the rhizosphere. The ECM symbioses formed by Thelephorales (Thelephora, Tomentella spp.) constituted the core community with absorptive roots in the spring and further colonized new root tips during the growing season. With an increase in soil salinity, the overall fungal abundance decreased, and Russula spp. and Cortinarius spp. were not present at all. Similarly, salinity also negatively affected the average length of the absorptive root. In conclusion, the endophytic microbiota in the rhizosphere of A. glutinosa was driven by salinity and season, while the ECM morphotype community was determined by the soil fungal community present during the growing season and renewed in the spring.
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Alnus , Basidiomycota , Microbiota , Micorrizas , Alnus/microbiología , Bacterias , Bosques , Suelo , Raíces de Plantas/microbiología , Microbiología del SueloRESUMEN
Tree-ring δ15N may depict site-specific, long-term patterns in nitrogen (N) dynamics under N2-fixing species, but field trials with N2-fixing tree species are lacking and the relationship of temporal patterns in tree-ring δ15N to soil N dynamics is controversial. We examined whether the tree-ring δ15N of N2-fixing red alder (Alnus rubra Bong.) would mirror N accretion rates and δ15N of soils and whether the influence of alder-fixed N could be observed in the wood of a neighboring conifer. We sampled a 27-year-old replacement series trial on south-eastern Vancouver Island, with red alder and coastal Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) planted in five proportions (0/100, 11/89, 25/75, 50/50 and 100/0) at a uniform stem density. An escalation in forest floor N content was evident with an increasing proportion of red alder, equivalent to a difference of ~750 kg N ha-1 between 100% Douglas-fir versus 100% alder. The forest floor horizon also had high δ15N values in treatments with more red alder. Red alder had a consistent quadratic fit in tree-ring δ15N over time, with a net increase of $\sim$1.5, on average, from initial values, followed by a plateau or slight decline. Douglas-fir tree-ring δ15N, in contrast, was largely unchanged over time (in three of four plots) but was significantly higher in the 50/50 mix. The minor differences in current leaf litter N content and δ15N between alder and Douglas-fir, coupled with declining growth in red alder, suggests the plateau or declining trend in alder tree-ring δ15N could coincide with lower N2-fixation rates, potentially by loss in alder vigor at canopy closure, or down-regulation via nitrate availability.
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Alnus , Pseudotsuga , Nitrógeno , Árboles/fisiología , Bosques , Plantas , Pseudotsuga/fisiologíaRESUMEN
Diarylheptanoids are secondary metabolites of plants that comprise a C6-C7-C6 scaffold. They can be broadly classified into linear-type and cyclic-type diarylheptanoids based on their chemical structures. Actinorhizal trees, such as Casuarina, Alnus, and Myrica, which form nodule symbiosis with actinomycetes Frankia, produce cyclic diarylheptanoids (CDHs); in Alnus sieboldiana Matsum. in particular, we have reported that the addition of CDHs leads to an increase in the number of nodules. However, the information available on the biosynthesis of CDHs is scarce. A greater number of plants CDHs (including those isolated from actinorhizal trees) with a saturated heptane chain have been isolated compared with linear, non-cyclic diarylheptanoids. To identify the genes involved in the synthesis of these compounds, genes with significant sequence similarity to existing plant double-bond reductases were screened in A. sieboldiana. This report describes the isolation and characterization of two A. sieboldiana double-bond reductases (AsDBR1 and AsDBR2) that catalyze the NADPH-dependent reduction of bisdemethoxycurcumin and curcumin. The optimum pH for the two enzymes was 5.0. The apparent Km values for bisdemethoxycurcumin and NADPH were 4.24 and 3.53 µM in the case of AsDBR1, and 2.55 and 2.13 µM for AsDBR2. The kcat value was 9.4-fold higher for AsDBR1 vs. AsDBR2 when using the bisdemethoxycurcumin substrate. Interestingly, the two AsDBRs failed to reduce the phenylpropanoid monomer.
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Alnus , Alnus/química , NADP , Diarilheptanoides/química , Plantas , Árboles , Oxidorreductasas , Clonación MolecularRESUMEN
Alnus nepalensis and Schima wallichii are native tree species accompanying succession in abandoned agricultural land in the middle mountainous region of central Nepal. To understand how root fungi recover during spontaneous succession, we analyzed the diversity and composition of arbuscular mycorrhizal (AM), ectomycorrhizal (ECM), and total fungi in tree fine roots from three land use types, short-term abandoned land (SA), long-term abandoned land (LA), and regenerated forest (RF) as a reference. Additionally, ECM morphotypes were examined. The results showed different speeds of succession in the studied fungal groups. While the change in the AM fungal community appears to be rapid and LA resembles the composition of RF, the total fungi in the abandoned land types are similar to each other but differed significantly from RF. Interestingly, the relative abundance of Archaeosporaceae followed a trend differing between the tree species (SA < LA in A. nepalensis, but SA > LA in S. wallichii). Unlike AM and total fungi, there was no significant difference in the ECM community of A. nepalensis between land use types, probably due to their low species diversity (9 ECM morphotypes, 31 ECM operational taxonomic units). However, Cortinarius sp. was significantly more abundant in RF than in the other land use types, whereas Alnicola, Tomentella, and Russula preferred young stages. Our results suggest that for both studied tree species the AM fungal succession could reach the stage of regenerated forest relatively fast. In the case of total fungi, because of hyperdiversity and composed of species specialized to a variety of environments and substrates, the transition was expected to be delayed in abandoned land where the vegetation was still developing and the ecosystem was not as complex as that found in mature forests.
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Agaricales , Alnus , Micorrizas , Microbiología del Suelo , Bosques , Ecosistema , Árboles/microbiología , Suelo , HongosRESUMEN
Frankia strain Ag45/Mut15T was isolated from a root nodule of Alnus glutinosa growing in a swamp at lake Grossensee, Germany. The strain forms root nodules on A. glutinosa, in which it produces hyphae and clusters of N2-fixing vesicles. N2-fixing vesicles are also produced in nitrogen-free growth medium, in addition to hyphae and sporangia. The whole-cell hydrolysates of strain Ag45/Mut15T contained meso-diaminopimelic acid in the peptidoglycan and ribose, xylose, mannose, glucose, galactose and a trace of rhamnose as cell-wall sugars. The major polar lipids were phosphatidylglycerol, phosphatidylinositol, diphosphatidylglycerol and glyco-phospholipid. The predominant (>20â%) menaquinones were MK-9(H6) and MK-9(H4). The major fatty acid profile (>10â%) consisted of iso-C16:0, C17â:â1 ω8c and C17â:â0. Pairwise 16S rRNA gene distances showed that strain Ag45/Mut15T was most closely related to Frankia torreyi CpI1T and Candidatus Frankia nodulisporulans with 16S rRNA gene similarity values of 0.001335 substitutions per site. An multilocus sequence analysis phylogeny based on atpD, dnaA, ftsZ, pgk and rpoB amino acid sequences positioned the strain within cluster 1 of Alnus- and Myrica-nodulating species, close to Candidatus F. nodulisporulans AgTrST and F. canadensis ARgP5T. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between the studied strain Ag45/Mut15T and all validly named Frankia species were below the defined threshold for prokaryotic species demarcation. Candidatus F. nodulisporulans AgTrST, which cannot be cultivated in vitro, was found to be the closest phylogenetic neighbour to strain strain Ag45/Mut15T with dDDH and ANI values of 61.8 and 97â%, respectively. Strain Ag45/Mut15T was not able to sporulate in nodule tissues like strain AgTrST.Phenotypic, physiological and phylogenomic analyses confirmed the assignment of strain Ag45/Mut15T (=DSM 114737T=LMG 326O1T) to a novel species, with Ag45/Mut15T as type strain, for which the name Frankia umida sp. nov. is proposed.
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Alnus , Frankia , Ácidos Grasos/química , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Composición de Base , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana , Fosfolípidos/química , Vitamina K 2/químicaRESUMEN
Iron overload causes multiorgan dysfunction and serious damage. Alnus incana from the family Betulaceae, widely distributed in North America, is used for treating diseases. In this study, we investigated the iron chelating, antioxidant, anti-inflammatory, and antiapoptotic activities of the total and butanol extract from Alnus incana in iron-overloaded rats and identified the bioactive components in both extracts using liquid chromatography-mass spectrometry. We induced iron overload in the rats via six intramuscular injections of 12.5 mg iron dextran/100 g body weight for 30 days. The rats were then administered 60 mg ferrous sulfate /kg body weight once daily using a gastric tube. The total and butanol extracts were given orally, and the reference drug (deferoxamine) was administered subcutaneously for another month. After two months, we evaluated the biochemical, histopathological, histochemical, and immunohistochemical parameters. Iron overload significantly increased the serum iron level, liver biomarker activities, hepatic iron content, malondialdehyde, tumor necrosis factor-alpha, and caspase-3 levels. It also substantially (P < 0.05) reduced serum albumin, total protein, and total bilirubin content, and hepatic reduced glutathione levels. It caused severe histopathological alterations compared to the control rats, which were markedly (P < 0.05) ameliorated after treatment. The total extract exhibited significantly higher anti-inflammatory and antiapoptotic activities but lower antioxidant and iron-chelating activities than the butanol extract. Several polyphenolic compounds, including flavonoids and phenolic acids, were detected by ultraperformance liquid chromatography-electrospray ionization-quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS) analysis. Our findings suggest that both extracts might alleviate iron overload-induced hepatoxicity and other pathological conditions characterized by hepatic iron overload, including thalassemia and sickle-cell anemia.
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Alnus , Enfermedad Hepática Inducida por Sustancias y Drogas , Sobrecarga de Hierro , Ratas , Animales , Antioxidantes/metabolismo , Extractos Vegetales/química , Sobrecarga de Hierro/metabolismo , Hierro/metabolismo , Hígado/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Antiinflamatorios/farmacología , Butanoles/metabolismoRESUMEN
The primary succession of ectomycorrhizal (ECM) fungi has been well described for Pinus and Salix, but the succession for other pioneer hosts is almost unknown. Here, we investigated ECM fungal communities of Alnus sieboldiana at different host growth stages in a primary successional volcanic site on Izu-Oshima Island, Japan. ECM root tips were collected from 120 host individuals, encompassing seedling, sapling, and mature tree stages. The taxonomic identity of the ECM fungi was determined based on rDNA internal transcribed spacer region sequences. Nine molecular taxonomic units were detected from a total of 807 root tips. The initial ECM fungal community on the pioneer seedlings was composed of only three species, where an undescribed Alpova species (Alpova sp.) was exclusively frequent. With host growth, other ECM fungal species were added to the communities, while the initial colonizers remained even at mature tree stages. Thus, the ECM fungal composition significantly changed along host growth stages and showed the nested community structure. Although most of the ECM fungi confirmed in this study had a broad Holarctic geographical distribution, the Alpova sp. had no previous records in other regions. These results suggest that a locally evolved Alpova sp. plays an essential role in the initial seedling establishment of A. sieboldiana at early successional volcanic sites.
Asunto(s)
Alnus , Basidiomycota , Micorrizas , Alnus/genética , Alnus/microbiología , Japón , Basidiomycota/genética , ADN Ribosómico/genética , Árboles/microbiología , Plantones/microbiología , HongosRESUMEN
Bark beetles (Coleoptera: Curculionidae; Scolytinae) are tree-infesting insects that consume subcortical tissues and fungi. Species capable of killing their host trees are most commonly associated with conifers, as very few bark beetle species infest and kill hardwood hosts directly. The alder bark beetle, Alniphagus aspericollis, is a hardwood-killing bark beetle that colonizes and kills red alder, Alnus rubra. Conifer-killing bark beetles have well-known associations with symbiotic ophiostomatoid fungi that facilitate their life histories, but it is unknown whether A. aspericollis has any fungal associates. This study was conducted to identify any consistent filamentous fungal associates of A. aspericollis and characterize the consistency of observed beetle-fungus relationships. Beetles and gallery phloem samples were collected from seven sites throughout the Greater Vancouver region in British Columbia, Canada. Filamentous fungi were isolated from these samples and identified by DNA barcoding using the internal transcribed spacer (ITS) region and other barcode regions for resolution to the species-level for the most dominant isolates. The most common fungal associate was a previously undescribed Neonectria major-like fungus, Neonectria sp. nov., which was isolated from ~67% of adult beetles, ~59% of phloem samples, and ~94% of the beetle-infested trees. Ophiostoma quercus was isolated from ~28% of adult beetles, ~9% of phloem samples, and ~56% of infested trees and deemed a casual associate of A. aspericollis, while a putatively novel species of Ophiostoma was more infrequently isolated from A. aspericollis and its galleries. Cadophora spadicis, a new record for red alder, was rarely isolated and is probably coincidentally carried by A. aspericollis. Overall, A. aspericollis was only loosely associated with ophiostomatoid fungi, suggesting that these fungi have little ecological significance in the beetle-tree interaction, while Neonectria sp. nov. may be a symbiote of A. aspericollis that is vectored by the beetle.
Asunto(s)
Alnus , Escarabajos , Hypocreales , Tracheophyta , Gorgojos , Animales , Gorgojos/microbiología , Corteza de la Planta/microbiología , Colombia BritánicaRESUMEN
Nitrogen-fixing Nepalese alder (Alnus nepalensis D. Don.), a pioneer species and nurse tree species, forms pure stands, and sometimes occurs in mixed stands in areas affected by landslides. The objective of this study was to understand the influence of A. nepalensis on carbon stock in white oak (Quercus leucotrichophora A. Camus) forests. We investigated the differences in vegetation biomass carbon (tree, sapling, seedling, shrub and herbs, and forest floor mass), soil organic carbon stock, and sequestration rates in five naturally occurring oak mixed alder (OMA) forest stands and five naturally occurring oak without alder (OWA) forest stands along the basal area gradient in order to investigate the role of A. nepalensis on ecosystem carbon stock. The total basal area ranged from 61.20 to 89.51 m2 ha-1 in the OMA stands and from 38.02 to 53.54 m2 ha-1 in the OWA stands. The total tree density of the OMA stands (1120 to 1330 trees ha-1) was higher than that of the OWA stands (950 to 1230 trees ha-1). The total ecosystem carbon stock in the OMA stands was significantly (P<0.05) higher than that in the OWA stands, ranging from 485.3 to 635.6 Mg C ha-1 in the former and from 378.8 to 472 Mg C ha-1 in the latter. Soil was the second largest carbon pool in all the studied stands, with the values ranging from 238.1 to 254.1 Mg C ha-1 in the OMA and 185.5 to 215.8 Mg C ha-1 in the OWA stands. The soil organic carbon (SOC) stock was 1.19 to 1.28 times higher in the OMA than in the OWA stands. Of the total ecosystem carbon stock in different OMA stands, A. nepalensis stored 16.2 to 38.8%. Annual carbon sequestration rates (6.6 to 9.5 Mg C ha-1 yr-1) in the OMA stands were significantly (P<0.05) higher than in the OWA (2.5 to 5.4 Mg C ha-1 yr-1) stands. Among all the species and across the stands, the greatest carbon sequestration was exhibited by A. nepalensis (3.4 to 5.3 Mg C ha-1 yr-1). The present results show the role of A. nepalensis in ecosystem carbon stock and sequestration rates. Significantly higher rates of carbon sequestration by oak in OMA stands than OWA stands clearly indicate the facilitative role of co-occurring nitrogen-fixing A. nepalensis. The results imply that Q. leucotrichophora mixed with a A. nepalensis plantation may be a good option for enhancing ecosystem carbon stock, carbon sequestration, and habitat restoration in the central Himalaya.
Asunto(s)
Alnus , Carbono , Ecosistema , Bosques , Quercus , Árboles , Alnus/metabolismo , Biomasa , Carbono/análisis , Carbono/metabolismo , Nepal , Quercus/metabolismo , Suelo/química , Árboles/química , Árboles/metabolismo , Fijación del Nitrógeno/fisiologíaRESUMEN
Red alder (Alnus rubra Bong.) is an ecologically significant and important fast-growing commercial tree species native to western coastal and riparian regions of North America, having highly desirable wood, pigment, and medicinal properties. We have sequenced the genome of a rapidly growing clone. The assembly is nearly complete, containing the full complement of expected genes. This supports our objectives of identifying and studying genes and pathways involved in nitrogen-fixing symbiosis and those related to secondary metabolites that underlie red alder's many interesting defense, pigmentation, and wood quality traits. We established that this clone is most likely diploid and identified a set of SNPs that will have utility in future breeding and selection endeavors, as well as in ongoing population studies. We have added a well-characterized genome to others from the order Fagales. In particular, it improves significantly upon the only other published alder genome sequence, that of Alnus glutinosa. Our work initiated a detailed comparative analysis of members of the order Fagales and established some similarities with previous reports in this clade, suggesting a biased retention of certain gene functions in the vestiges of an ancient genome duplication when compared with more recent tandem duplications.