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Microorganisms Jun 2024Soil bacterial communities play a remarkable role in nutrient cycling, significantly affecting soil organic material content, soil fertility, and, in an indirect way,...
Soil bacterial communities play a remarkable role in nutrient cycling, significantly affecting soil organic material content, soil fertility, and, in an indirect way, plant succession processes. Conversely, vegetation type influences microbial soil life. The present study compared the bacterial microbiome composition, diversity and catabolic activity profile of topsoil samples collected under three different forest types (a twice-coppiced black locust stand, a young, naturally reforested, and a middle-aged mixed pedunculate oak stand) planted on former arable land in the early 20th century. Diversity indices determined during 16S ribosomal RNA sequencing-based metagenome analysis indicated that the black locust stand had the highest soil bacterial community diversity. At the phylum level, Acidobacteriota, Actinobacteriota, Proteobacteria, Verrucomicrobiota, Bacteroidota, and Gemmatimonadota were the most abundant taxa in the forest soils. Concerning soil parameters, redundancy analysis revealed that pH had the highest impact on bacterial community structure and pH, and soil organic carbon content on the samples' respiration patterns. As for catabolic activity, the recently clearcut oak forest showed the lowest substrate-induced respiration, and citrate was the main driver for the inter-stand variability of microbial activity. Our results confirm that soil parameters and forest type influence the composition and functioning of the soil bacterial microbiome.
PubMed: 38930544
DOI: 10.3390/microorganisms12061162 -
BMC Plant Biology Aug 2012Genetic markers and linkage mapping are basic prerequisites for comparative genetic analyses, QTL detection and map-based cloning. A large number of mapping populations... (Comparative Study)
Comparative Study
BACKGROUND
Genetic markers and linkage mapping are basic prerequisites for comparative genetic analyses, QTL detection and map-based cloning. A large number of mapping populations have been developed for oak, but few gene-based markers are available for constructing integrated genetic linkage maps and comparing gene order and QTL location across related species.
RESULTS
We developed a set of 573 expressed sequence tag-derived simple sequence repeats (EST-SSRs) and located 397 markers (EST-SSRs and genomic SSRs) on the 12 oak chromosomes (2n = 2x = 24) on the basis of Mendelian segregation patterns in 5 full-sib mapping pedigrees of two species: Quercus robur (pedunculate oak) and Quercus petraea (sessile oak). Consensus maps for the two species were constructed and aligned. They showed a high degree of macrosynteny between these two sympatric European oaks. We assessed the transferability of EST-SSRs to other Fagaceae genera and a subset of these markers was mapped in Castanea sativa, the European chestnut. Reasonably high levels of macrosynteny were observed between oak and chestnut. We also obtained diversity statistics for a subset of EST-SSRs, to support further population genetic analyses with gene-based markers. Finally, based on the orthologous relationships between the oak, Arabidopsis, grape, poplar, Medicago, and soybean genomes and the paralogous relationships between the 12 oak chromosomes, we propose an evolutionary scenario of the 12 oak chromosomes from the eudicot ancestral karyotype.
CONCLUSIONS
This study provides map locations for a large set of EST-SSRs in two oak species of recognized biological importance in natural ecosystems. This first step toward the construction of a gene-based linkage map will facilitate the assignment of future genome scaffolds to pseudo-chromosomes. This study also provides an indication of the potential utility of new gene-based markers for population genetics and comparative mapping within and beyond the Fagaceae.
Topics: Alleles; Chromosome Mapping; Chromosomes, Plant; Evolution, Molecular; Expressed Sequence Tags; Gene Order; Genetic Linkage; Genetic Variation; Genome Size; Genome, Plant; Inheritance Patterns; Karyotype; Microsatellite Repeats; Quantitative Trait Loci; Quercus; Sympatry; Synteny
PubMed: 22931513
DOI: 10.1186/1471-2229-12-153 -
Tree Physiology Jul 2021Research on wood phenology has mainly focused on reactivation of the cambium in spring. In this study we investigated if summer drought advances cessation of wood...
Research on wood phenology has mainly focused on reactivation of the cambium in spring. In this study we investigated if summer drought advances cessation of wood formation and if it has any influence on wood structure in late successional forest trees of the temperate zone. The end of xylogenesis was monitored between August and November in stands of European beech and pedunculate oak in Belgium for two consecutive years, 2017 and 2018, with the latter year having experienced an exceptional summer drought. Wood formation in oak was affected by the drought, with oak trees ceasing cambial activity and wood maturation about 3 weeks earlier in 2018 compared with 2017. Beech ceased wood formation before oak, but its wood phenology did not differ between years. Furthermore, between the 2 years, no significant difference was found in ring width, percentage of mature fibers in the late season, vessel size and density. In 2018, beech did show thinner fiber walls, whereas oak showed thicker walls. In this paper, we showed that summer drought can have an important impact on late season wood phenology xylem development. This will help to better understand forest ecosystems and improve forest models.
Topics: Droughts; Ecosystem; Seasons; Trees; Wood; Xylem
PubMed: 33616191
DOI: 10.1093/treephys/tpaa175 -
The New Phytologist Sep 2021Leaves interact with a wealth of microorganisms. Among these, fungi are highly diverse and are known to contribute to plant health, leaf senescence and early...
Leaves interact with a wealth of microorganisms. Among these, fungi are highly diverse and are known to contribute to plant health, leaf senescence and early decomposition. However, patterns and drivers of the seasonal dynamics of foliar fungal communities are poorly understood. We used a multifactorial experiment to investigate the influence of warming and tree genotype on the foliar fungal community on the pedunculate oak Quercus robur across one growing season. Fungal species richness increased, evenness tended to decrease, and community composition strongly shifted during the growing season. Yeasts increased in relative abundance as the season progressed, while putative fungal pathogens decreased. Warming decreased species richness, reduced evenness and changed community composition, especially at the end of the growing season. Warming also negatively affected putative fungal pathogens. We only detected a minor imprint of tree genotype and warming × genotype interactions on species richness and community composition. Overall, our findings demonstrate that warming plays a larger role than plant genotype in shaping the seasonal dynamics of the foliar fungal community on oak. These warming-induced shifts in the foliar fungal community may have a pronounced impact on plant health, plant-fungal interactions and ecosystem functions.
Topics: Ecosystem; Genotype; Mycobiome; Quercus; Seasons
PubMed: 33960441
DOI: 10.1111/nph.17434 -
HNO Oct 1953
Topics: Humans; Neoplasms; Palatine Tonsil; Tonsillar Neoplasms
PubMed: 13128506
DOI: No ID Found -
Journal of Plant Physiology Jan 2003This study was performed in order to investigate whether the actual requirement for defence against photo-oxidative stress is reflected by the alpha-tocopherol...
This study was performed in order to investigate whether the actual requirement for defence against photo-oxidative stress is reflected by the alpha-tocopherol (alpha-Toco) content in leaves of pedunculate oak (Quercus robur L.). Antioxidants and pigments were quantified in leaves that were collected on six days between May and September 2000 in a mixed pine/oak forest at canopy positions differing in light environment. Pools of hydrophilic antioxidants and photo-protective xanthophyll cycle pigments (V + A + Z) reflected the anti-oxidative demand, as these pools increased with the average light intensity to which the leaves were acclimated. The photo-protective demand was not the determinant of the alpha-Toco content of oak leaves, as (1) foliage of a young oak, exposed to low light levels in the understorey, contained higher amounts of this lipophilic antioxidant than leaves sampled from semimature oaks at canopy positions with a similar light environment, and (2) a strong increase in the alpha-Toco content over the growing season was detected at each investigated crown position, whereas the V + A + Z pool did not show a concomitant accumulation during leaf ageing. The rate of alpha-Toco accumulation differed distinctly between samples taken at different canopy positions.
Topics: Acclimatization; Antioxidants; Light; Oxidative Stress; Pigments, Biological; Plant Leaves; Quercus; Seasons; Xanthophylls; alpha-Tocopherol
PubMed: 12685051
DOI: 10.1078/0176-1617-00952 -
PloS One 2021Natural succession of vegetation on abandoned farmland provides opportunities for passive rewilding to re-establish native woodlands, but in Western Europe the patterns...
Natural succession of vegetation on abandoned farmland provides opportunities for passive rewilding to re-establish native woodlands, but in Western Europe the patterns and outcomes of vegetation colonisation are poorly known. We combine time series of field surveys and remote sensing (lidar and photogrammetry) to study woodland development on two farmland fields in England over 24 and 59 years respectively: the New Wilderness (2.1 ha) abandoned in 1996, and the Old Wilderness (3.9 ha) abandoned in 1961, both adjacent to ancient woodland. Woody vegetation colonisation of the New Wilderness was rapid, with 86% vegetation cover averaging 2.9 m tall after 23 years post-abandonment. The Old Wilderness had 100% woody cover averaging 13.1 m tall after 53 years, with an overstorey tree-canopy (≥ 8 m tall) covering 91%. By this stage, the structural characteristics of the Old Wilderness were approaching those of neighbouring ancient woodlands. The woody species composition of both Wildernesses differed from ancient woodland, being dominated by animal-dispersed pedunculate oak Quercus robur and berry-bearing shrubs. Tree colonisation was spatially clustered, with wind-dispersed common ash Fraxinus excelsior mostly occurring near seed sources in adjacent woodland and hedgerows, and clusters of oaks probably resulting from acorn hoarding by birds and rodents. After 24 years the density of live trees in the New Wilderness was 132/ha (57% oak), with 390/ha (52% oak) in the Old Wilderness after 59 years; deadwood accounted for 8% of tree stems in the former and 14% in the latter. Passive rewilding of these 'Wilderness' sites shows that closed-canopy woodland readily re-established on abandoned farmland close to existing woodland, it was resilient to the presence of herbivores and variable weather, and approached the height structure of older woods within approximately 50 years. This study provides valuable long-term reference data in temperate Europe, helping to inform predictions of the potential outcomes of widespread abandonment of agricultural land in this region.
Topics: Conservation of Natural Resources; Ecosystem; Forests; Trees
PubMed: 34133452
DOI: 10.1371/journal.pone.0252466 -
The Journal of Animal Ecology Nov 2022Climate change has been shown to advance spring phenology, increase the number of insect generations per year (multivoltinism) and increase pathogen infection levels....
Climate change has been shown to advance spring phenology, increase the number of insect generations per year (multivoltinism) and increase pathogen infection levels. However, we lack insights into the effects of plant spring phenology and the biotic environment on the preference and performance of multivoltine herbivores and whether such effects extend into the later part of the growing season. To this aim, we used a multifactorial growth chamber experiment to examine the influence of spring phenology on plant pathogen infection, and how the independent and interactive effects of spring phenology and plant pathogen infection affect the preference and performance of multigenerational attackers (the leaf miner Tischeria ekebladella and the aphid Tuberculatus annulatus) on the pedunculate oak in the early, mid and late parts of the plant growing season. Pathogen infection was highest on late phenology plants, irrespective of whether inoculations were conducted in the early, mid or late season. The leaf miner consistently preferred to oviposit on middle and late phenology plants, as well as healthy plants, during all parts of the growing season, whereas we detected an interactive effect between spring phenology and pathogen infection on the performance of the leaf miner. Aphids preferred healthy, late phenology plants during the early season, healthy plants during the mid season, and middle phenology plants during the late season, whereas aphid performance was consistently higher on healthy plants during all parts of the growing season. Our findings highlight that the impact of spring phenology on pathogen infection and the preference and performance of insect herbivores is not restricted to the early season, but that its imprint is still present - and sometimes equally strong - during the peak and end of the growing season. Plant pathogens generally negatively affected herbivore preference and performance, and modulated the effects of spring phenology. We conclude that spring phenology and pathogen infection are two important factors shaping the preference and performance of multigenerational plant attackers, which is particularly relevant given the current advance in spring phenology, pathogen outbreaks and increase in voltinism with climate change.
Topics: Animals; Seasons; Herbivory; Quercus; Plants; Insecta; Climate Change; Aphids; Temperature; Plant Leaves
PubMed: 36047365
DOI: 10.1111/1365-2656.13804 -
Metabolites Oct 2021Two species of oak are dominant in French forests: pedunculate oak () and sessile oak (.). Their differentiation is not straightforward but is essential to better...
Two species of oak are dominant in French forests: pedunculate oak () and sessile oak (.). Their differentiation is not straightforward but is essential to better understand their respective molecular content in order to better valorize them. Thus, to improve oak species identification, an untargeted UHPLC-HRMS/MS method associated with a two-step data treatment was developed to analyze a wide range of specialized metabolites enabling the comparison of both species of oak extracts. Pooled extracts from sessile and pedunculate oaks, composed of extracts from several trees of pure species from various origins, were compared using first the Venn diagram, as a quick way to get an initial idea of how close the extracts are, and then using a molecular network to visualize, on the one hand, the ions shared between the two species and, on the other hand, the compounds specific to one species. The molecular network showed that the two species shared common clusters mainly representative of tannins derivatives and that each species has specific molecules with similar fragmentation patterns, associated in specific clusters. This methodology was then applied to compare these two pooled extracts to unknown individuals in order to determine the species. The Venn diagram allowed for the quick presumption of the species of the individual and then the species could be assigned more precisely with the molecular network, at the level of specific clusters. This method, developed for the first time, has several interests. First, it makes it possible to discriminate the species and to correctly assign the species of unknown samples. Moreover, it gave an overview of the metabolite composition of each sample to better target oak tree utilization and valorization.
PubMed: 34677399
DOI: 10.3390/metabo11100684 -
Ultraschall in Der Medizin (Stuttgart,... Jan 2011The objective of the present study was to investigate the prevalence of gallbladder polyps and possible risk factors in a random population sample of an urban population.
PURPOSE
The objective of the present study was to investigate the prevalence of gallbladder polyps and possible risk factors in a random population sample of an urban population.
MATERIAL AND METHODS
A total of 2099 subjects (1072 women, 1027 men; aged 19 - 65 years, mean age 42.1 (SD ± 12.8 years) were prospectively examined using ultrasound, a standardized questionnaire and laboratory studies.
RESULTS
Gallbladder polyps were identified in 6.1 % (128 / 2099) of all subjects (women: 6.1 % [63 / 1027]); men: 6.1 % [65 / 1072]). Solitary polyps were found in 52.4 % (65 / 124), two polyps in 16.1 % (20 / 124), three polyps in 6.5 % (8 / 124), several polyps in 22.6 % (28 / 124) and multiple polyps in 2.4 % (3 / 124) of subjects. The mean polyp diameter was 4.7 mm (SD ± 2.2; range 2 - 20 mm). The polyp diameter was ≤ 7 mm in 94.5 % of subjects. The polyps were described as pedunculate in 82.3 % (102 / 124). The polyps were broad-based in 11.3 % of subjects (14 / 124; men: 18 % women: 4.8 %). The polyps were homogeneously echogenic in 100 % of cases and with irregular contours in only one male subject. Multiple logistic regression failed to demonstrate an influence on the increased occurrence of gallbladder polyps for the risk factors of male sex, age, body-mass index (BMI), alcohol, nicotine or caffeine consumption or diabetes mellitus.
CONCLUSION
The prevalence of gallbladder polyps reported in the present study (6.1 %) is higher than figures previously published for populations in Germany or Europe. The majority of polyps were pedunculate and solitary. A typical risk factor profile for gallbladder polyps could not be identified in the present population sample.
Topics: Adult; Aged; Cross-Sectional Studies; Female; Gallbladder Diseases; Germany; Health Surveys; Humans; Male; Middle Aged; Polyps; Risk Factors; Ultrasonography; Young Adult
PubMed: 20414857
DOI: 10.1055/s-0029-1245265