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1.
Improvement of root architecture under abiotic stress through control of auxin homeostasis in Arabidopsis and Brassica crops
Branka Salopek-Sondi, Stephan Pollmann, Kristina Gruden, Ralf Oelmüller, Jutta Ludwig-Müller, 2015, original scientific article

Abstract: Auxin plays an important role in many aspects of plant development including stress responses. Here we briefly summarize how auxin is involved in salt stress, drought (i.e. mostly osmotic stress), waterlogging and nutrient deficiency in Brassica plants. In addition, some mechanisms to control auxin levels and signaling in relation to root formation (under stress) will be reviewed. Molecular studies are mainly described for the model plant Arabidopsis thaliana, but we also like to demonstrate how this knowledge can be transferred to agriculturally important Brassica species, such as Brassica rapa, Brassica napus and Brassica campestris. Moreover, beneficial fungi could play a role in the adaptation response of Brassica roots to abiotic stresses. Therefore, the possible influence of Piriformospora indica will also be covered since the growth promoting response of plants colonized by P. indica is also linked to plant hormones, among them auxin.
Keywords: auxin, root development, abiotic stress
Published in DiRROS: 29.07.2024; Views: 129; Downloads: 59
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2.
Arthropod communities in fungal fruitbodies are weakly structured by climate and biogeography across European beech forests
Nicolas Friess, Jörg C. Müller, Pablo Aramendi, Claus Bässler, Martin P. Brändle, Christophe Bouget, Antoine Brin, Heinz Bussler, Kostadin B. Georgiev, Radosław Gil, Martin M. Gossner, Jacob Heilmann-Clausen, Gunnar Isacsson, Anton Krištín, Thibault Lachat, Laurent Larrieu, Elodie Magnanou, Alexander Maringer, Ulrich Mergner, Martin Mikoláš, Lars Opgenoorth, Jürgen Schmidl, Miroslav Svoboda, Simon Thorn, Kris Vandekerkhove, Al Vrezec, Thomas Wagner, Maria-Barbara Winter, Livia Zapponi, Roland Brandl, Sebastian Seibold, 2019, original scientific article

Abstract: Aim The tinder fungus Fomes fomentarius is a pivotal wood decomposer in European beech Fagus sylvatica forests. The fungus, however, has regionally declined due to centuries of logging. To unravel biogeographical drivers of arthropod communities associated with this fungus, we investigated how space, climate and habitat amount structure alpha and beta diversity of arthropod communities in fruitbodies of F. fomentarius. Location Temperate zone of Europe. Taxon Arthropods. Methods We reared arthropods from fruitbodies sampled from 61 sites throughout the range of European beech and identified 13 orders taxonomically or by metabarcoding. We estimated the total number of species occurring in fruitbodies of F. fomentarius in European beech forests using the Chao2 estimator and determined the relative importance of space, climate and habitat amount by hierarchical partitioning for alpha diversity and generalized dissimilarity models for beta diversity. A subset of fungi samples was sequenced for identification of the fungus’ genetic structure. Results The total number of arthropod species occurring in fruitbodies of F. fomentarius across European beech forests was estimated to be 600. Alpha diversity increased with increasing fruitbody biomass; it decreased with increasing longitude, temperature and latitude. Beta diversity was mainly composed by turnover. Patterns of beta diversity were only weakly linked to space and the overall explanatory power was low. We could distinguish two genotypes of F. fomentarius, which showed no spatial structuring. Main conclusion Fomes fomentarius hosts a large number of arthropods in European beech forests. The low biogeographical and climatic structure of the communities suggests that fruitbodies represent a habitat that offers similar conditions across large gradients of climate and space, but are characterized by high local variability in community composition and colonized by species with high dispersal ability. For European beech forests, retention of trees with F. fomentarius and promoting its recolonization where it had declined seems a promising conservation strategy.
Keywords: dead wood, insects, invertebrates, restoration, saproxylic, sporocarp
Published in DiRROS: 23.07.2024; Views: 285; Downloads: 71
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3.
Evidence for senescence in survival but not in reproduction in a short-lived passerine
Rémi Fay, Michael Schaub, Jennifer A. Border, Ian G. Henderson, Georg Fahl, Jürgen Feulner, Petra Horch, Mathis Müller, Helmut Rebstock, Dmitry Shitikov, Davorin Tome, Matthias Vögeli, Martin U. Grüebler, 2020, original scientific article

Abstract: Senescence has been studied since a long time by theoreticians in ecology and evolution, but empirical support in natural population has only recently been accumulating. One of the current challenges is the investigation of senescence of multiple fitness components and the study of differences between sexes. Until now, studies have been more frequently conducted on females than on males and rather in long-lived than in short-lived species. To reach a more fundamental understanding of the evolution of senescence, it is critical to investigate age-specific survival and reproduction performance in both sexes and in a large range of species with contrasting life histories. In this study, we present results on patterns of age-specific and sex-specific variation in survival and reproduction in the whinchat Saxicola rubetra, a short-lived passerine. We compiled individual-based long-term datasets from seven populations that were jointly analyzed within a Bayesian modeling framework. We found evidence for senescence in survival with a continuous decline after the age of 1 year, but no evidence of reproductive senescence. Furthermore, we found no clear evidence for sex effects on these patterns. We discuss these results in light of previous studies documenting senescence in short-lived birds. We note that most of them have been conducted in populations breeding in nest boxes, and we question the potential effect of the nest boxes on the shape of age-reproductive trajectories.
Keywords: actuarial senescence, age-specific demographic rate, aging, Saxicola rubetra, whinchat
Published in DiRROS: 22.07.2024; Views: 124; Downloads: 80
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4.
Interlaboratory comparison study on ribodepleted total RNA high-throughput sequencing for plant virus diagnostics and bioinformatic competence
Yahya Gaafar, Marcel Westenberg, Marleen Botermans, László Krizbai, Kris De Jonghe, Yoika Foucart, Luca Ferretti, Denis Kutnjak, Anja Pecman, Nataša Mehle, Jan F. Kreuze, Giovanna Müller, Nikolaos Vakirlis, Despoina Beris, Christina Varveri, Heiko Ziebell, 2021, original scientific article

Abstract: High-throughput sequencing (HTS) technologies and bioinformatic analyses are of growing interest to be used as a routine diagnostic tool in the field of plant viruses. The reliability of HTS workflows from sample preparation to data analysis and results interpretation for plant virus detection and identification must be evaluated (verified and validated) to approve this tool for diagnostics. Many different extraction methods, library preparation protocols, and sequence and bioinformatic pipelines are available for virus sequence detection. To assess the performance of plant virology diagnostic laboratories in using the HTS of ribosomal RNA depleted total RNA (ribodepleted totRNA) as a diagnostic tool, we carried out an interlaboratory comparison study in which eight participants were required to use the same samples, (RNA) extraction kit, ribosomal RNA depletion kit, and commercial sequencing provider, but also their own bioinformatics pipeline, for analysis. The accuracy of virus detection ranged from 65% to 100%. The false-positive detection rate was very low and was related to the misinterpretation of results as well as to possible cross-contaminations in the lab or sequencing provider. The bioinformatic pipeline used by each laboratory influenced the correct detection of the viruses of this study. The main difficulty was the detection of a novel virus as its sequence was not available in a publicly accessible database at the time. The raw data were reanalysed using Virtool to assess its ability for virus detection. All virus sequences were detected using Virtool in the different pools. This study revealed that the ribodepletion target enrichment for sample preparation is a reliable approach for the detection of plant viruses with different genomes. A significant level of virology expertise is needed to correctly interpret the results. It is also important to improve and complete the reference data.
Keywords: high-throughput sequencing, ribodepletion, interlaboratory comparison, test performance study, proficiency test, Virtool
Published in DiRROS: 19.07.2024; Views: 135; Downloads: 79
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5.
On some aspects of spectral theory for infinite bounded non-negative matrices in max algebra
Vladimir Müller, Aljoša Peperko, 2024, original scientific article

Abstract: Several spectral radii formulas for infinite bounded non-negative matrices in max algebra are obtained. We also prove some Perron–Frobenius type results for such matrices. In particular, we obtain results on block triangular forms, which are similar to results on Frobenius normal form of $n \times n$ matrices. Some continuity results are also established.
Keywords: non-negative matrices, infinite bounded matrices, max algebra, Bonsall’s cone spectral radius, eigenvalues, continuity
Published in DiRROS: 30.05.2024; Views: 265; Downloads: 245
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6.
Fast and accurate multiplex identification and quantification of seven genetically modified soybean lines using six-color digital PCR
Alexandra Bogožalec Košir, Sabine Muller, Jana Žel, Mojca Milavec, Allison C. Mallory, David Dobnik, 2023, original scientific article

Abstract: The proliferation of genetically modified organisms (GMOs) presents challenges to GMO testing laboratories and policymakers. Traditional methods, like quantitative real-time PCR (qPCR), face limitations in quantifying the increasing number of GMOs in a single sample. Digital PCR (dPCR), specifically multiplexing, offers a solution by enabling simultaneous quantification of multiple GMO targets. This study explores the use of the Naica six-color Crystal dPCR platform for quantifying five GM soybean lines within a single six-plex assay. Two four-color assays were also developed for added flexibility. These assays demonstrated high specificity, sensitivity (limit of detection or LOD < 25 copies per reaction) and precision (bias to an estimated copy number concentration <15%). Additionally, two approaches for the optimization of data analysis were implemented. By applying a limit-of-blank (LOB) correction, the limit of quantification (LOQ) and LOD could be more precisely determined. Pooling of reactions additionally lowered the LOD, with a two- to eight-fold increase in sensitivity. Real-life samples from routine testing were used to confirm the assays’ applicability for quantifying GM soybean lines in complex samples. This study showcases the potential of the six-color Crystal dPCR platform to revolutionize GMO testing, facilitating comprehensive analysis of GMOs in complex samples.
Keywords: digital PCR, dPCR, quantification, multiplexing, genetically modified organisms, 6-color system, virus diagnostics, virology
Published in DiRROS: 29.03.2024; Views: 379; Downloads: 164
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