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Frontiers in Plant Science 2016Spring flooding in riparian forests can cause significant reductions in earlywood-vessel size in submerged stem parts of ring-porous tree species, leading to the...
Spring flooding in riparian forests can cause significant reductions in earlywood-vessel size in submerged stem parts of ring-porous tree species, leading to the presence of 'flood rings' that can be used as a proxy to reconstruct past flooding events, potentially over millennia. The mechanism of flood-ring formation and the relation with timing and duration of flooding are still to be elucidated. In this study, we experimentally flooded 4-year-old Quercus robur trees at three spring phenophases (late bud dormancy, budswell, and internode expansion) and over different flooding durations (2, 4, and 6 weeks) to a stem height of 50 cm. The effect of flooding on root and vessel development was assessed immediately after the flooding treatment and at the end of the growing season. Ring width and earlywood-vessel size and density were measured at 25- and 75-cm stem height and collapsed vessels were recorded. Stem flooding inhibited earlywood-vessel development in flooded stem parts. In addition, flooding upon budswell and internode expansion led to collapsed earlywood vessels below the water level. At the end of the growing season, mean earlywood-vessel size in the flooded stem parts (upon budswell and internode expansion) was always reduced by approximately 50% compared to non-flooded stem parts and 55% compared to control trees. This reduction was already present 2 weeks after flooding and occurred independent of flooding duration. Stem and root flooding were associated with significant root dieback after 4 and 6 weeks and mean radial growth was always reduced with increasing flooding duration. By comparing stem and root flooding, we conclude that flood rings only occur after stem flooding. As earlywood-vessel development was hampered during flooding, a considerable number of narrow earlywood vessels present later in the season, must have been formed after the actual flooding events. Our study indicates that root dieback, together with strongly reduced hydraulic conductivity due to anomalously narrow earlywood vessels in flooded stem parts, contribute to reduced radial growth after flooding events. Our findings support the value of flood rings to reconstruct spring flooding events that occurred prior to instrumental flood records.
PubMed: 27379108
DOI: 10.3389/fpls.2016.00775 -
The New Phytologist 2008This study presents the isolation and characterization of a novel nonsymbiotic Hb gene from sessile oak (Quercus petraea) seedlings, herein designated QpHb1. The...
This study presents the isolation and characterization of a novel nonsymbiotic Hb gene from sessile oak (Quercus petraea) seedlings, herein designated QpHb1. The cellular and tissue expression of QpHb1 was analysed by Northern blotting and in situ hybridization. The encoded protein was predicted to consist of 161 amino acid residues, and shares 71 and 51% amino acid sequence identity with the Arabidopsis class 1 and 2 nonsymbiotic Hb, respectively. Northern blot analysis revealed that QpHb1 was strongly expressed in roots. Spatial expression analysis of QpHb1 in the root apical region of sessile oak by in situ hybridization indicated that transcripts were mostly abundant in protoxylem cell initials, some cortical cells and the protoderm. In addition, when comparing the expression profile of QpHb1 in sessile and pedunculate oak (Quercus robur), two species with contrasted hypoxia tolerance, the transcript level of QpHb1 rose early in the most flood-tolerant species, pedunculate oak, during root submergence. The spatial-temporal expression of QpHb1 suggests that this gene could participate in perception and signalling during hypoxia.
Topics: Amino Acid Sequence; Cloning, Molecular; Gene Expression Profiling; Gene Expression Regulation, Plant; Hemoglobins; In Situ Hybridization; Molecular Sequence Data; Organ Specificity; Oxygen; Phylogeny; Plant Proteins; Plant Roots; Plant Shoots; Quercus; RNA, Plant; Water
PubMed: 17986182
DOI: 10.1111/j.1469-8137.2007.02250.x -
Tree Genetics & Genomes Feb 2019Reproduction, one of the main components of plant fitness, is highly variable in response to environmental cues, but little is known about the genetic determinism...
Reproduction, one of the main components of plant fitness, is highly variable in response to environmental cues, but little is known about the genetic determinism underlying reproduction-related traits in forest tree species. There is therefore an urgent need to characterize the genetic architecture of those traits if we are to predict the evolutionary trajectories of forest populations facing rapidly changing environment and mitigate their impacts. Using a full-sib family of pedunculate oak (), we investigated the within population variability of seed production and mean seed mass during four consecutive years. Reproductive traits were highly variable between trees and between years. The high narrow sense heritability and evolvability estimated underline the important genetic effect on the variability in seed production and mean seed mass. Despite a large variability over years, reproductive traits show significant genetic correlation between years. Furthermore, for the first time in forest tree species, quantitative trait loci (QTLs) associated with seed production and mean mass of a seed have been identified. While it is commonly assumed and observed that fitness-traits have low narrow sense heritabilities, our findings show that reproduction-related traits may undergo evolutionary changes under selective pressure and may be determinant for tree adaptation.
PubMed: 30546292
DOI: 10.1007/s11295-018-1309-2 -
Life (Basel, Switzerland) Mar 2023Oak bark is a rich niche for beneficial bioactive compounds. It is known that the amount of the compounds found in plant tissues can depend on species, genotype, growth...
Oak bark is a rich niche for beneficial bioactive compounds. It is known that the amount of the compounds found in plant tissues can depend on species, genotype, growth site, etc., but it is unclear whether oak phenology, i.e., late or early bud burst, can also influence the amount of phenols and antioxidants that can be extracted. We tested two populations expressing different phenology and five half-sib families in each population to see how phenology, genotype, as well as extrahent differences (75% methanol or water) can determine the total phenol, total flavonoid content, as well as antioxidant activity. Significant statistical differences were found between half-sib families of the same population, between populations representing different oak phenology and different extrahents used. We determined that the extraction of flavonoids was more favorable when using water. So was antioxidant activity using one of the indicators, when significant differences between extrahents were observed. Furthermore, in families where there was a significant difference, phenols showed better results when using methanol. Overall, late bud burst families exhibited higher levels in all parameters tested. Thus, we recommend that for further bioactive compound extraction, all these factors be noted.
PubMed: 36983864
DOI: 10.3390/life13030710 -
AJNR. American Journal of Neuroradiology Mar 2006The imaging appearance of facial nerve schwannomas (FNSs) has been described as an enhancing tubular mass (using T1-enhanced MR) within an enlarged facial nerve canal...
BACKGROUND AND PURPOSE
The imaging appearance of facial nerve schwannomas (FNSs) has been described as an enhancing tubular mass (using T1-enhanced MR) within an enlarged facial nerve canal (using CT). The purpose of this study is to identify how often the FNS imaging findings conform to this description and determine whether there are underlying anatomic explanations for the discrepant imaging appearances identified.
MATERIALS AND METHODS
The clinical, pathologic, and radiologic records of 24 FNS in 23 patients were retrospectively reviewed. Each FNS was evaluated for location along the facial nerve. The lesions were cataloged by facial nerve segment with the imaging characteristics of each segment described.
RESULTS
The average age at time of first imaging was 39 years (age range, 10-70 years). Eighteen (71%) of the 24 FNSs were pathologically confirmed, while the others were determined intraoperatively or diagnostically by the presence of both enlargement of the facial nerve canal and enhancement on contrast-enhanced T1 MR examination. The most common location was in the geniculate fossa (83%), followed by the labyrinthine and tympanic segments of the facial nerve (both 54%). The most common clinical presentation was facial neuropathy (42%).
CONCLUSION
The classic description of FNS on enhanced T1 MR is that of a well-circumscribed fusiform enhancing mass along the course of the intratemporal facial nerve with bone algorithm CT showing sharply defined bony canal enlargement. Modern imaging techniques, however, demonstrate the importance of the surrounding anatomic landscape, leading to various imaging appearances. Lesions traversing the labyrinthine segment can demonstrate a dumbbell appearance. When FNSs track along the greater superficial petrosal nerve, they may present as a round mass projecting up into the middle cranial fossa. FNS of the tympanic segment of the facial nerve preferentially pedunculate into the middle ear cavity, clinically presenting as a middle ear mass. When the mastoid segment of the facial nerve is involved, irregular and "invasive" tumor margins seen on MR can be explained on CT as tumor breaking into surrounding mastoid air cells.
Topics: Adolescent; Adult; Aged; Child; Cranial Nerve Neoplasms; Facial Nerve Diseases; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Neurilemmoma; Tomography, X-Ray Computed
PubMed: 16552018
DOI: No ID Found -
World Journal of Clinical Cases Jul 2019Because the duodenum is fixed onto the retroperitoneum, duodenal intussusception is usually impossible except in cases of malrotational abnormality. Although cases of...
BACKGROUND
Because the duodenum is fixed onto the retroperitoneum, duodenal intussusception is usually impossible except in cases of malrotational abnormality. Although cases of duodenal intussusception without malrotational abnormalities have been reported, it is unclear whether they constitute true intussusception or simple mucosal prolapse.
CASE SUMMARY
A 66-year-old woman presented with whole-body edema and malaise. Blood analysis indicated severe anemia and cholestasis. Endoscopic examination revealed a pedunculate polyp on the second part of the duodenum that migrated distally with mucosal elongation. Computed tomography showed duodenal intussusception. A tumor as the lead point and retroperitoneal structure, including the head of the pancreas and fat, invaginated beyond the duodenojejunal flexure. She was diagnosed with ampullary adenoma caused repeated intussusception that reduced spontaneously and underwent pancreaticoduodenectomy. Laparotomy showed tumor prolapse beyond the duodenojejunal flexure without intussusception. There was no evidence of malrotational abnormality. She was discharged with no complications.
CONCLUSION
We report true duodenal intussusception without malrotational abnormality. This phenomenon was also associated with mucosal prolapse.
PubMed: 31417932
DOI: 10.12998/wjcc.v7.i14.1857 -
Frontiers in Plant Science 2018Anticipating the evolutionary responses of long-lived organisms, such as trees, to environmental changes, requires the assessment of genetic variation of adaptive traits...
Anticipating the evolutionary responses of long-lived organisms, such as trees, to environmental changes, requires the assessment of genetic variation of adaptive traits in natural populations. To this end, high-density markers are needed to calculate genomic relatedness between individuals allowing to estimate the genetic variance of traits in wild populations. We designed a targeted capture-based, next-generation sequencing assay based on the highly heterozygous pedunculate oak () reference genome, for the sequencing of 3 Mb of genic and intergenic regions. Using a mixed stand of 293 and genotypes we successfully captured over 97% of the target sequences, corresponding to 0.39% of the oak genome, with sufficient depth (97×) for the detection of about 190,000 SNPs evenly spread over the targeted regions. We validated the technique by evaluating its reproducibility, and comparing the genomic relatedness of trees with their known pedigree relationship. We explored the use of the technique on other related species and highlighted the advantages and limitations of this approach. We found that 92.07% of target sequences in and 70.36% of sequences in were captured. We used this SNP resource to estimate genetic relatedness in the mixed oak stand. Mean pairwise genetic relatedness was low within each species with a few values exceeding 0.25 (half-sibs) or 0.5 (full-sibs). Finally, we applied the technique to a long-standing issue in population genetics of trees regarding the relationship between inbreeding and components of fitness. We found very weak signals for inbreeding depression for reproductive success and no signal for growth within both species.
PubMed: 30057586
DOI: 10.3389/fpls.2018.00996 -
Journal of Parasitic Diseases :... Jun 2019Two new species of Hermann (Monogenea: Mazocraeidae) are described infecting clupeoid fishes of Visakhapatnam coast, Bay of Bengal: n. sp. from Cuvier and n. sp....
Two new species of Hermann (Monogenea: Mazocraeidae) are described infecting clupeoid fishes of Visakhapatnam coast, Bay of Bengal: n. sp. from Cuvier and n. sp. from van Hasselt and Lacepede. n.sp. is distinguished from the most closely related species (, , , ) by the combination of following characters: Body size, extent of caeca, number and arrangement of testes, size and structure of the clamps and the armature of genital complex. n. sp. differs from all the other species of in the pedunculate nature and the sizes of the haptoral clamps and the structure of the genital complex. A detailed analysis of the species of the genus is presented. The partial 28SrDNa sequences of was generated and deposited in the GenBank.
PubMed: 31263339
DOI: 10.1007/s12639-019-01095-6 -
The New Phytologist Aug 2022Many plant species produce multiple leaf flushes during the growing season, which might have major consequences for within-plant variation in chemistry and species...
Many plant species produce multiple leaf flushes during the growing season, which might have major consequences for within-plant variation in chemistry and species interactions. Yet, we lack a theoretical or empirical framework for how differences among leaf flushes might shape variation in damage by insects and diseases. We assessed the impact of leaf flush identity on leaf chemistry, insect attack and pathogen infection on the pedunculate oak Quercus robur by sampling leaves from each leaf flush in 20 populations across seven European countries during an entire growing season. The first leaf flush had higher levels of primary compounds, and lower levels of secondary compounds, than the second flush, whereas plant chemistry was highly variable in the third flush. Insect attack decreased from the first to the third flush, whereas infection by oak powdery mildew was lowest on leaves from the first flush. The relationship between plant chemistry, insect attack and pathogen infection varied strongly among leaf flushes and seasons. Our findings demonstrate the importance of considering differences among leaf flushes for our understanding of within-tree variation in chemistry, insect attack and disease levels, something particularly relevant given the expected increase in the number of leaf flushes with climate change.
Topics: Animals; Insecta; Plant Leaves; Quercus; Seasons; Trees
PubMed: 35514157
DOI: 10.1111/nph.18209 -
Royal Society Open Science Mar 2019Soil detritivores such as Collembola impact plant growth, tissue nutrient concentration and gene expression. Using a model system with pedunculate oak () microcuttings...
Soil detritivores such as Collembola impact plant growth, tissue nutrient concentration and gene expression. Using a model system with pedunculate oak () microcuttings that display a typical endogenous rhythmic growth with alternating shoot (SF) and root flushes (RF), we investigated the transcriptomic response of oak with and without mycorrhiza () to the presence of Collembola (), and linked it to changes in resource allocation by pulse labelling the plants with C and N. Collembola impacted Gene Ontology (GO) terms as well as plant morphology and elemental ratios with the effects varying markedly with developmental phases. During SF Collembola increased GO terms related to primary growth and this was mirrored in increased C and N excess in aboveground plant compartments. During RF, Collembola increased GO terms related to plant secondary metabolism and physical fortification. Further, Collembola presence resulted in an increase in plant defence-related GO terms suggesting that Collembola in the rhizosphere prime oak shoots against the attack by fungi or herbivores. Notably, the impact of Collembola on growth, resource allocation and oak gene expression was modified by presence of . The results indicate that oaks clearly react to the presence of Collembola in the rhizosphere and respond in a complex way by changing the expression of genes of both primary and secondary metabolism, and this resulted in concomitant changes in plant morphology and physiology.
PubMed: 31032040
DOI: 10.1098/rsos.181869