Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2017
Abstract
The plant hormone auxin is a vital component for plant reproduction as it regulates the development of both male and female reproductive organs, including ovules and gynoecia. Furthermore, auxin plays important roles in the development and growth of seeds and fruits. Auxin responses can be detected in ovules shortly after fertilization, and it has been suggested that this accumulation is a prerequisite for the developmental reprogramming of the ovules to seeds, and of the gynoecium to a fruit. However, the roles of auxin at the final stages of ovule development, and the sources of auxin leading to the observed responses in ovules after fertilization have remained elusive. Here we have characterized the auxin readout in Arabidopsis ovules, at the pre-anthesis, anthesis and in the immediate post-fertilization stages, using the R2D2 auxin sensor. In addition we have mapped the expression of auxin biosynthesis and conjugation genes, as well as that of auxin transporting proteins, during the same developmental stages. These analyses reveal specific spatiotemporal patterns of the different auxin homeostasis regulators. Auxin biosynthesis genes and auxin transport proteins define a prepatterning of vascular cell identity in the pre-anthesis funiculus. Furthermore, our data suggests that auxin efflux from the ovule is restricted in an anther-dependent manner, presumably to synchronize reproductive organ development and thereby optimizing the chances of successful fertilization. Finally, de novo auxin biosynthesis together with reduced auxin conjugation and transport result in an enhanced auxin readout throughout the sporophytic tissues of the ovules soon after fertilization. Together, our results suggest a sophisticated set of regulatory cascades that allow successful fertilization and the subsequent transition of the female reproductive structures into seeds and fruits.
Authors
Rolf Nestby Sebastien GuéryAbstract
OBJECT: Improved precision fertilization by introducing sensors and remote control to secure fruit yield and reduce nutrient leaching in soil culture. MATERIAL AND METHODS:We broadcasted before bedding and mulching 50 g m–2 of a multi-mineral fertilizer. Beds had two plant rows 20 cm apart, with plant distance of 25 cm. Experimental design was split plot with three replications and three treatments. Treatments: fertigation in large plots, cultivar in small plots and year. RESULTS: Plant development in the establishing year had no benefit of fertigation in addition to fertilizer given before bedding. When the yield is 3 kg m–2 a nutrient solution of 6 g N m–2 gave highest yield, using 4 g m–2 from two weeks before harvest and during harvest. ‘Florence’ and ‘Sonata’ developed well; however, ‘Florence’ had mildew on fruits in the last cropping year. ‘Korona’ presented well the first cropping year, but grew small fruits heavily infested by mildew in the last cropping year. CONCLUSION: Fertilization had effect on fruit yield. It is discussed how a fertilization schedule for the establishment year and cropping years can be adapted to plant development stages. Mildew infestation on fruits was dependent of cultivar and fertilization. Introducing sensors for recording of growth factors and in situ ion-levels of soil water nutrients, proved valuable.
Abstract
Large-scale bark beetle outbreaks in northern conifer forests have already demonstrated huge impacts on forest economy, ecosystems and carbon dynamics. In North America, a historically unprecedented outbreak of the mountain pine beetle has expanded north- and eastwards beyond its historical range, and has reached epidemic levels in areas of northern British Columbia previously thought to be unsuitable for beetle survival. In Europe, the vast northern spruce forests have been spared from bark beetle outbreaks in the past, but here we review some recent observations and research results indicating that this may be undergoing change. For example, monitoring data of the most serious tree-killing bark beetle in Europe, Ips typographus, show a several-fold increase of the populations in its northern range during warm years. In the extensive spruce forests of northern Fennoscandia and Russia, a new phenomenon of tree-killing episodes by I. typographus has occurred in the last decade. Northern localities with one beetle generation per year in the past are now having more often two. Also other bark beetle species in the genus Ips have demonstrated a fast northward expansion in Europe, including one species contributing in bark beetle outbreaks of I. typographus in Central and Southern Europe.
Authors
Håvard Steinshamn Karl-Christian Mahnert Inga Marie Aasen Spiridoula Athanasiadou Heidi L Enemark Kristin SørheimAbstract
No abstract has been registered
Authors
Monica Matei Lucian Laslo DEÁK György Ciobotaru Nicu Mădălina Boboc Marius Raischi Cristina Mușat Theodor Lupei Simona Raischi Andreea Moncea Diana Dumitru Gabriel Badea Lampros Lamprinakis Divina Gracia P. Rodriguez Anne Prestvik Asbjørn Veidal Björn KlimekAbstract
No abstract has been registered
Authors
Carrie Joy Andrew Einar Heegaard Paul M. Kirk Claus Bässler Jacob Heilmann-Clausen Irmgard Krisai-Greilhuber Thomas W. Kuyper Beatrice Senn-Irlet Ulf Büntgen Jeffrey Michael Diez Simon Egli Alan C. Gange Rune Halvorsen Klaus Høiland Jenni Nordén Fredrik Rustøen Lynne Boddy Håvard KauserudAbstract
Species occurrence observations are increasingly available for scientific analyses through citizen science projects and digitization of museum records, representing a largely untapped ecological resource. When combined with open-source data, there is unparalleled potential for understanding many aspects of the ecology and biogeography of organisms. Here we describe the process of assembling a pan-European mycological meta-database (ClimFun) and integrating it with open-source data to advance the fields of macroecology and biogeography against a backdrop of global change. Initially 7.3 million unique fungal species fruit body records, spanning nine countries, were processed and assembled into 6 million records of more than 10,000 species. This is an extraordinary amount of fungal data to address macro-ecological questions. We provide two examples of fungal species with different life histories, one ectomycorrhizal and one wood decaying, to demonstrate how such continental-scale meta-databases can offer unique insights into climate change effects on fungal phenology and fruiting patterns in recent decades. Keywords Biogeography; Citizen science; Fungi; Global change; Meta-database; Open-source
Abstract
No abstract has been registered
Authors
Claudia Kammann Jim Ippolito Nikolas Hagemann Nils Borchard Maria Luz Cayuela José M. Estavillo Teresa Fuertes-Mendizabal Simon Jeffery Jürgen Kern Jeff Novak Daniel Rasse Sanna Saarnio Hans-Peter Schmidt Kurt Spokas Nicole Wrage-MönnigAbstract
Agriculture and land use change has significantly increased atmospheric emissions of the non-CO2 green-house gases (GHG) nitrous oxide (N2O) and methane (CH4). Since human nutritional and bioenergy needs continue to increase, at a shrinking global land area for production, novel land management strategies are required that reduce the GHG footprint per unit of yield. Here we review the potential of biochar to reduce N2O and CH4 emissions from agricultural practices including potential mechanisms behind observed effects. Furthermore, we investigate alternative uses of biochar in agricultural land management that may significantly reduce the GHG-emissions-per-unit-of-product footprint, such as (i) pyrolysis of manures as hygienic alternative to direct soil application, (ii) using biochar as fertilizer carrier matrix for underfoot fertilization, biochar use (iii) as composting additive or (iv) as feed additive in animal husbandry or for manure treatment. We conclude that the largest future research needs lay in conducting life-cycle GHG assessments when using biochar as an on-farm management tool for nutrient-rich biomass waste streams.
Authors
Adam Thomas O'tooleAbstract
No abstract has been registered
Abstract
No abstract has been registered