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"Wilhelm, Eva"
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nsaio6 : neuer schmuck aus Idar-Oberstein = new jewellery from Idar-Oberstein
Beginning with the renaissance of gemstones in jewellery design since the 1970s, Ute Eitzenhèofer, Theo Smeets, Lothar Brèugel (ret. 2014) and Eva-Maria Kollischan (since 2014) successfully established the Hochschule Trier in Idar-Oberstein as a creative European jewellery centre. To mark the exhibition in the Stadtmusem Simeonstift in Trier on thirty years of the Gemstone and Jewellery Department, the publication shows an exciting selection of works from the last ten years. Works in creative design and photography accompany diverse approaches that exemplify the contemporary use of a reputedly 'outmoded' raw material. In exploring the aesthetic characteristics of the material and the experimental confrontation with its physical qualities, the gemstone's potential for design comes entirely into its own. Within current discourse it comments ironically, on the one hand, on the unilateral societal ascription as a luxury item; on the other, it functions as a charming and noble object of nature. Exhibition: Stadtmuseum Simeonstift Trier, Germany (27.01.16 - 26.02.2017).
Book
Erwinia amylovora Expresses Fast and Simultaneously hrp/dsp Virulence Genes during Flower Infection on Apple Trees
Pathogen entry through host blossoms is the predominant infection pathway of the gram-negative bacterium Erwinia amylovora leading to manifestation of the disease fire blight. Like in other economically important plant pathogens, E. amylovora pathogenicity depends on a type III secretion system encoded by hrp genes. However, timing and transcriptional order of hrp gene expression during flower infections are unknown.
Using quantitative real-time PCR analyses, we addressed the questions of how fast, strong and uniform key hrp virulence genes and the effector dspA/E are expressed when bacteria enter flowers provided with the full defense mechanism of the apple plant. In non-invasive bacterial inoculations of apple flowers still attached to the tree, E. amylovora activated expression of key type III secretion genes in a narrow time window, mounting in a single expression peak of all investigated hrp/dspA/E genes around 24-48 h post inoculation (hpi). This single expression peak coincided with a single depression in the plant PR-1 expression at 24 hpi indicating transient manipulation of the salicylic acid pathway as one target of E. amylovora type III effectors. Expression of hrp/dspA/E genes was highly correlated to expression of the regulator hrpL and relative transcript abundances followed the ratio: hrpA>hrpN>hrpL>dspA/E. Acidic conditions (pH 4) in flower infections led to reduced virulence/effector gene expression without the typical expression peak observed under natural conditions (pH 7).
The simultaneous expression of hrpL, hrpA, hrpN, and the effector dspA/E during early floral infection indicates that speed and immediate effector transmission is important for successful plant invasion. When this delicate balance is disturbed, e.g., by acidic pH during infection, virulence gene expression is reduced, thus partly explaining the efficacy of acidification in fire blight control on a molecular level.
Journal Article
Cultivation-independent population analysis of bacterial endophytes in three potato varieties based on eubacterial and Actinomycetes-specific PCR of 16S rRNA genes
Endophytic bacteria are ubiquitous in most plants and colonise plants without exhibiting pathogenicity. Studies on the diversity of bacterial endophytes have been mainly approached by characterisation of isolates obtained from internal tissues. Despite the broad application of culture-independent techniques for the analysis of microbial communities in a wide range of natural habitats, little information is available on the species diversity of endophytes. In this study, microbial communities inhabiting stems, roots and tubers of three potato varieties were analysed by 16S rRNA-based techniques such as terminal restriction fragment length polymorphism analysis, denaturing gradient gel electrophoresis as well as 16S rDNA cloning and sequencing. Two individual plant experiments were conducted. In the first experiment plants suffered from light deficiency, whereas healthy and robust plants were obtained in the second experiment. Plants obtained from both experiments showed comparable endophytic populations, but healthy potato plants possessed a significantly higher diversity of endophytes than stressed plants. In addition, plant tissue and variety specific endophytes were detected. Sequence analysis of 16S rRNA genes indicated that a broad phylogenetic spectrum of bacteria is able to colonise plants internally including alpha-, beta-, and gamma-Proteobacteria, high-GC Gram-positives, microbes belonging to the Flexibacter/Cytophaga/Bacteroides group and Planctomycetales. Group-specific analysis of Actinomycetes indicated a higher abundance and diversity of Streptomyces scabiei-related species in the variety Mehlige Muhlviertler, which is known for its resistance against potato common scab caused by S. scabiei.
Journal Article
Somatic Embryogenesis in Oak (Quercus spp.)
The present review summarizes the factors involved in controlling the process of oak somatic embryogenesis as a method for vegetative plant propagation and includes also data on artificial seed production, cryopreservation and transformation. One major limitation, the inability to initiate embryogenic cultures from mature trees, has been recently overcome. Leaves from selected cork oak trees with an age of 50 yr and more have been used to initiate somatic embryogenesis (SE) with a frequency of up to 20%. These findings offer encouraging prospects for cloning proven superior plant material and to integrate this propagation system into tree improvement programs. Once the process of SE has been initiated, the multiplication cycle proceeds via secondary embryogenesis, which can be maintained indefinitely. Problems are reported by the formation of anomalous embryos. The mutability of somatic embryogenic cell lines of various oak species has been monitored by flow cytometry and molecular markers. No somaclonal variation was detected applying random amplified polymorphic DNA (RAPD) or amplified fragment length polymorphism (AFLP) markers, whereas DNA-content measurements via flow cytometry revealed tetraploidy in some cell lines after several years of continuous subculture. Maturation and low germination frequencies are the main bottlenecks for a broader use of this technique. Recently attention has been on embryo quality and parameters for conversion capacity such as high endogenous cytokinin level and low abscisic acid (ABA) level. Although oak is probably the species that is the most well-developed system for a broadleaved forest tree, data on growth performances of somatic embryo-derived plants are rare.
Journal Article
Impact of Rehabilitation on Physical and Neuropsychological Health of Patients Who Acquired COVID-19 in the Workplace
Workers, especially healthcare workers, are exposed to an increased risk for SARS-CoV-2 infection. However, less is known about the impact of rehabilitation on health outcomes associated with post-COVID. This longitudinal observational study examined the changes in physical and neuropsychological health and work ability after inpatient rehabilitation of 127 patients (97 females/30 males; age 21–69 years; Mean = 50.62) who acquired COVID-19 in the workplace. Post-COVID symptoms, functional status, physical performance, neuropsychological health, employment, and work ability were assessed before and after rehabilitation. Group differences relating to sex, professions, and acute COVID status were also analyzed. Except for fatigue, the prevalence of all post-COVID symptoms decreased after rehabilitation. Significant improvements in physical performance and neuropsychological health outcomes were determined. Moreover, healthcare workers showed a significantly greater reduction in depressive symptoms compared to non-healthcare workers. Nevertheless, participants reported poor work ability, and 72.5% of them were still unable to work after discharge from rehabilitation. As most participants were still suffering from the impact of COVID-19 at rehabilitation discharge, ongoing strategies in aftercare are necessary to improve their work ability. Further investigations of this study population at 6 and 12 months after rehabilitation should examine the further course of post-COVID regarding health and work ability status.
Journal Article
Cultivation-independent population analysis of bacterial endophytes in three potato varieties based on eubacterial and Actinomycetes-specific PCR of 16S rRNA genes
Endophytic bacteria are ubiquitous in most plants and colonise plants without exhibiting pathogenicity. Studies on the diversity of bacterial endophytes have been mainly approached by characterisation of isolates obtained from internal tissues. Despite the broad application of culture-independent techniques for the analysis of microbial communities in a wide range of natural habitats, little information is available on the species diversity of endophytes. In this study, microbial communities inhabiting stems, roots and tubers of three potato varieties were analysed by 16S rRNA-based techniques such as terminal restriction fragment length polymorphism analysis, denaturing gradient gel electrophoresis as well as 16S rDNA cloning and sequencing. Two individual plant experiments were conducted. In the first experiment plants suffered from light deficiency, whereas healthy and robust plants were obtained in the second experiment. Plants obtained from both experiments showed comparable endophytic populations, but healthy potato plants possessed a significantly higher diversity of endophytes than stressed plants. In addition, plant tissue and variety specific endophytes were detected. Sequence analysis of 16S rRNA genes indicated that a broad phylogenetic spectrum of bacteria is able to colonise plants internally including α-, β-, and γ-Proteobacteria, high-GC Gram-positives, microbes belonging to the
Flexibacter/Cytophaga/Bacteroides group and Planctomycetales. Group-specific analysis of
Actinomycetes indicated a higher abundance and diversity of
Streptomyces scabiei-related species in the variety Mehlige Mühlviertler, which is known for its resistance against potato common scab caused by
S. scabiei.
Journal Article
Physiological and morphological characteristics during development of pedunculate oak (Quercus robur L.) zygotic embryos
The developmental stages of oak zygotic embryos (ZEs) are characterized here according to morphological and physiological features. Seeds were harvested from June to September in 1-week intervals. Excised embryos were classified into four stages of development by using growth parameters. For physiological characterization, endogenous levels of abscisic acid (ABA), indole-3-acetic acid (IAA), l-proline, starch content and water status were determined. The expression of the oak legumin storage protein gene was tested in immature cotyledonary ZEs before and after ABA treatment. The ABA levels of the embryos showed a significant peak during the intermediate stage of maturation (stage III) and then decreased again at the end of the late maturation phase (stage IV). Concomitant with ABA, the moisture content declined with the maximum embryo size. High IAA levels were found at the beginning of embryo enlargement as exponential growth occurred (stage II) but decreased during further development. Starch accumulated gradually in the course of maturation, whereas significant values were found in stage IV ZEs near shedding. Proline, on fresh weight basis, was high during stages I and II. Osmotic potential increased when, by rapid dry matter accumulation, stage II ZEs reached their maximum size during early intermediate development. Expression of precocious germination was higher on hormone-free medium, in particular, among stage II and stage III ZEs. Variations in phytohormone levels in combination with changes in tissue water status seem to be important factors for oak ZE development.
Journal Article
PLANT REGENERATION FROM ENCAPSULATED SOMATIC EMBRYOS OF PEDUNCULATE OAK (QUERCUS ROBUR L.)
Cotyledonary Quercus robur L. somatic embryos from two cell lines were encapsulated in 4% (w/v) sodium alginate. An artificial endosperm was provided by the addition of P24 medium plus 3% (w/v) sucrose. Oak somatic embryos and oak synthetic seeds were germinated on P24 medium plus 0.1 μM indole-3-butyric acid and 0.9 μM 6-benzylaminopurine or were dehydrated prior to germination. The highest conversion rates (26%) were obtained with encapsulated somatic embryos as well as artificial endosperm-coated somatic embryos. Encapsulation improved the regeneration into oak plantlets in one of the two cell lines tested. The artificial endosperm had no additional beneficial effect on conversion frequency, but increased germination rate in one cell line tested. Significant higher conversion could be attributed to slow desiccation compared to the non-encapsulated control. Cold storage as a post-maturation treatment had no influence on the germination ability of oak synthetic seeds. Differences in the response of the cell lines with respect to conversion frequencies and timing of germination were observed. Fifty-six well-developed plantlets regenerated 12 wk after germination, and 29 plants were transferred to the greenhouse, where they have been successfully established in substrate.
Journal Article
Ubiquitin and fusarium resistance: Lessons from wheat cDNAS conferring deoxynivalenol resistance in yeast
The production of the trichothecene mycotoxin deoxynivalenol (DON) is an important virulence factor of the plant pathogenic fungus Fusarium graminearum on wheat. We have engineered a DON sensitive yeast strain and constructed a cDNA library from DON treated wheat suspension culture cells in a yeast expression vector. The library was used to select DON resistance conferring clones. Besides ORFs of unknown function, we found 3 classes of cDNAs that in addition to DON resistance conferred hypersensitivity to hygromycin and canavanine. The predicted functions of several of the wheat cDNAs (putative E3 ligase, ubiquitin specific protease, proteasome subunit) suggested a role for ubiquitin-proteasome mediated protein degradation in DON resistance. Results with a coupled wheat germ in vitro translation system and a GUS-luciferase fusion gene showed that DON is a powerful translation elongation inhibitor. The truncated proteins formed in the presence of DON most likely lead to ubiquitin depletion and consequently growth inhibition in yeast. Ubiquitin is essential for many processes in plants, including plant defense. Our results warrant the re-evaluation of the relevance of proteasome system components found to be differentially regulated during Fusarium infection.
Journal Article
Organ-specific defence strategies of pepper (Capsicum annuum L.) during early phase of water deficit
Drought is one of the major factors that limits crop production and reduces yield. To understand the early response of plants under nearly natural conditions, pepper plants (Capsicum annuum L.) were grown in a greenhouse and stressed by withholding water for 1 week. Plants adapted to the decreasing water content of the soil by adjustment of their osmotic potential in root tissue. As a consequence of drought, strong accumulation of raffinose, glucose, galactinol and proline was detected in the roots. In contrast, in leaves the levels of fructose, sucrose and also galactinol increased. Due to the water deficit cadaverine, putrescine, spermidine and spermine accumulated in leaves, whereas the concentration of polyamines was reduced in roots. To study the molecular basis of these responses, a combined approach of suppression subtractive hybridisation and microarray technique was performed on the same material. A total of 109 unique ESTs were detected as responsive to drought, while additional 286 ESTs were selected from the bulk of rare transcripts on the array. The metabolic profiles of stressed pepper plants are discussed with respect to the transcriptomic changes detected, while attention is given to the differences between defence strategies of roots and leaves.
Journal Article