2020
Authors
Carlos Sacristan Carlos G Das Neves Faisal Suhel Irene Sacristán Torstein Tengs Inger Sofie Hamnes Knut Ivar Engesæter MadslienAbstract
Bartonella spp. are fastidious, Gram‐negative, aerobic, facultative intracellular bacteria that infect humans, domestic and wild animals. In Norway, Bartonella spp. have been detected in cervids, mainly within the distribution area of the arthropod vector deer ked (Lipoptena cervi ). We used PCR to survey the prevalence of Bartonella spp. in blood samples from 141 cervids living outside the deer ked distribution area (moose [Alces alces , n = 65], red deer [Cervus elaphus , n = 41], and reindeer [Rangifer tarandus , n = 35]), in 44 pool samples of sheep tick (Ixodes ricinus , 27 pools collected from 74 red deer and 17 from 45 moose) and in biting midges of the genus Culicoides (Diptera: Ceratopogonidae, 120 pools of 6710 specimens). Bartonella DNA was amplified in moose (75.4 %, 49/65) and in red deer (4.9 %, 2/41) blood samples. All reindeer were negative. There were significant differences in Bartonella prevalence among the cervid species. Additionally, Bartonella was amplified in two of 17 tick pools collected from moose and in 3 of 120 biting midge pool samples. The Bartonella sequences amplified in moose, red deer and ticks were highly similar to B. bovis , previously identified in cervids. The sequence obtained from biting midges was only 81.7 % similar to the closest Bartonella spp. We demonstrate that Bartonella is present in moose across Norway and present the first data on northern Norway specimens. The high prevalence of Bartonella infection suggests that moose could be the reservoir for this bacterium. This is the first report of bacteria from the Bartonella genus in ticks from Fennoscandia, and in Culicoides biting midges worldwide.
Authors
Yongjie Kuang Shaofang Li Bing Ren Fang Yan Carl Jonas Jorge Spetz Xiangju Li Xueping Zhou Huanbin ZhouAbstract
Recently developed CRISPR-mediated base editors, which enable the generation of numerous nucleotide changes in target genomic regions, have been widely adopted for gene correction and generation of crop germplasms containing important gain-of-function genetic variations. However, to engineer target genes with unknown functional SNPs remains challenging. To address this issue, we present here a base-editing-mediated gene evolution (BEMGE) method, employing both Cas9n-based cytosine and adenine base editors as well as a single-guide RNA (sgRNA) library tiling the full-length coding region, for developing novel rice germplasms with mutations in any endogenous gene. To this end, OsALS1 was artificially evolved in rice cells using BEMGE through both Agrobacterium-mediated and particle-bombardment-mediated transformation. Four different types of amino acid substitutions in the evolved OsALS1, derived from two sites that have never been targeted by natural or human selection during rice domestication, were identified, conferring varying levels of tolerance to the herbicide bispyribac-sodium. Furthermore, the P171F substitution identified in a strong OsALS1 allele was quickly introduced into the commercial rice cultivar Nangeng 46 through precise base editing with the corresponding base editor and sgRNA. Collectively, these data indicate great potential of BEMGE in creating important genetic variants of target genes for crop improvement.
Abstract
The main objective of this paper is to present the new model BASGRA_N, to show how it was parameterized for grass swards in Scandinavia, and to evaluate its performance in predicting above-ground biomass, crude protein, cell wall content and dry matter digestibility. The model was developed to allow simulation of: (1) the impact of N-supply on the plants and their environment, (2) the dynamics of greenhouse gas emissions from grasslands, (3) the dynamics of cell-wall content and digestibility of leaves and stems, which could not be simulated with its predecessor, the BASGRA-model. To calibrate and test the model, we used field experimental data. One dataset included observations of biomass (DM) and crude protein content (CP) under different N fertilizer regimes from five sites in central and southern Sweden. The other dataset included observations of DM, and sward components as well as CP, cell wall content (NDF) and DM digestibility as affected by harvesting regime from one site in southwestern Norway. The total number of experiments was nine, of which three were used for model testing. When BASGRA_N was run with the maximum a-posteriori (MAP) parameter vector from the Bayesian calibration for the Swedish test sites, DM and CP were both simulated to an overall Pearson correlation coefficient (Rb) of minimum 0.58, Willmott's index of agreement (d) of minimum 0.69 and normalized root mean squared error (NRMSE) of maximum 0.30. Corresponding metrics for Norwegian test sites were 0.93, 0.96 and 0.27 for DM and > 0.73, > 0.61, < 0.18 for DM digestibility, NDF and CP content, respectively. We conclude that BASGRA_N can be used to simulate yield and CP responses to N with satisfactory precision, while maintaining key features from its predecessor. The results also suggest that DM digestibility and NDF can be simulated satisfactorily, which is supported by results from a recent model comparison study. Further testing of the model is needed for a few variables for which we currently do not have enough data, notably leaching and emission of N-containing compounds. Further work will include application of the model to investigate greenhouse gas mitigation options, and evaluation against independent data for the conditions for which it will be applied.
Abstract
Nature in Norway (NiN) has detailed ecological definitions of a high number of ecosystem units, but its applicability in practical vegetation mapping is unknown because it was not designed with a specific mapping method in mind. To investigate this further, two methods for mapping – 3D aerial photographic interpretation of colour infrared photos and field survey – were used to map comparable sites. The classification accuracy of each method was evaluated using 160 randomly distributed plots. The results show an overall classification accuracy of 62.5% for 3D aerial photographic interpretation and 82.5% for field survey. However, the accuracy varied for the ecosystem units mapped. The classification accuracy of ecosystem units in acidic, dry and open terrain was similar for both methods, whereas classification accuracy of calcareous units was highest using field survey. The mapping progress using 3D aerial photographic interpretation was more than two times faster than that of field survey. Based on the results, the authors recommend a method combining 3D aerial photographic interpretation and field survey to achieve effectively accurate mapping in practical applications of the NiN system.
Abstract
Denne rapporten beskriver utviklingen av en ny metode og en digital kartløsning for å visualisere ulike økosystemtjenester på nasjonal skala i Norge.
Authors
Sille Rebane Kalev Jõgiste Andres Kiviste John A. Stanturf Ahto Kangur Marek MetslaidAbstract
Growth of CO2 concentration level has strong interactions with forests. Forests are able to sequester carbon (C) through photosynthesis and can help to mitigate the effects of climate warming, as well as to reduce the CO2 concentration in the atmosphere. Drought and other extreme weather conditions play a key role in ecosystem functioning and the C-cycle. The eddy covariance (EC) method can be used to better understand forest ecosystems CO2 exchange by directly measuring net carbon and water fluxes. In our study, EC results for measurement of fluxes between the atmosphere and forest canopy are reported for the study period from May to August 2018 in Järvselja, Estonia. Stand-replacing disturbance (clear-cutting) took place in April 2013. The young forest stand is dominated by Norway spruce (Picea abies) and birch (Betula spp.). Findings so far include (1) a C-budget for the study period that showed a slight C-sink status; (2) net ecosystem exchange (NEE) was −0.0084 µmol m−2 s−1 indicating C-uptake during the measurement period; (3) in May, June, July and August, NEE was −0.027, −0.015, 0.001 and 0.006 µmol m−2 s−1, respectively; (4) NEE fluxes are lower in drought conditions and are affected by temperature that averaged 15 °C.
Abstract
No abstract has been registered
Authors
Fernanda C. N. Esteca Nina Trandem Ingeborg Klingen Jandir Cruz Santos Italo Delalibera Júnior Gilberto José de MoraesAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Susanne von Bargen Rim Al Kubrusli Thomas Gaskin Stephanie Fürl Florian Hüttner Dag-Ragnar Blystad David G. Karlin Risto Jalkanen Carmen BüttnerAbstract
Since Emaraviruses have been discovered in 2007 several new species were detected in a range of host plants. Five genome segments of a novel Emaravirus from mosaic‐diseased Eurasian aspen (Populus tremula) have been completely determined. The monocistronic, segmented ssRNA genome of the virus shows a genome organisation typical for Emaraviruses encoding the viral RNA‐dependent RNA polymerase (RdRP, 268.2 kDa) on RNA1 (7.1 kb), a glycoprotein precursor (GPP, 73.5 kDa) on RNA2 (2.3 kb), the viral nucleocapsid protein (N, 35.6 kDa) on RNA3 (1.6 kb), and a putative movement protein (MP, 41.0 kDa) on RNA4 (1.6 kb). The fifth identified genome segment (RNA5, 1.3 kb) encodes a protein of unknown function (P28, 28.1 kDa). We discovered that it is distantly related to proteins encoded by Emaraviruses, such as P4 of European mountain ash ringspot‐associated virus. All proteins from this group contain a central hydrophobic region with a conserved secondary structure and a hydrophobic amino acid stretch, bordered by two highly conserved positions, thus clearly representing a new group of homologues of Emaraviruses. The virus identified in Eurasian aspen is closely associated with observed leaf symptoms, such as mottle, yellow blotching, variegation and chloroses along veins. All five viral RNAs were regularly detectable by RT‐PCR in mosaic‐diseased P. tremula in Norway, Finland and Sweden (Fennoscandia). Observed symptoms and testing of mosaic‐diseased Eurasian aspen by virus‐specific RT‐PCR targeting RNA3 and RNA4 confirmed a wide geographic distribution of the virus in Fennoscandia. We could demonstrate that the mosaic‐disease is graft‐transmissible and confirmed that the virus is the causal agent by detection in symptomatic, graft‐inoculated seedlings used as rootstocks as well as in the virus‐infected scions used for graft‐inoculation. Owing to these characteristics, the virus represents a novel species within the genus Emaravirus and was tentatively denominated aspen mosaic‐associated virus.