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Genetic control of seasonal meristem arrest in trees
No full textPerennial plants, such as trees native to temperate and boreal regions, exhibit meristems that undergo annual cycles of activity and rest to synchronize their growth cycles withseasonal changes, ensuring survival under harsh winter conditions. The arrest of shootmeristem growth, known as growth cessation, is a critical initial step for trees to enterdormancy. This process is triggered by a combination of endogenous and exogenous signals, yet the molecular mechanisms and signaling pathways underlying growth ces-sation remain poorly understood. In this study, we demonstrate that Populus orthologs of APETALA2-like transcription factors (AP2Ls), the primary regulators of global pro-liferative arrest (GPA) in Arabidopsis, play a crucial role in the regulation of seasonal growth cessation in hybrid aspen trees. In particular, AP2Ls act as important activators of the expression of FLOWERING LOCUS T2 (FT2), a key gene for short-day- induced growth cessation. This contrasts with the established role of AP2Ls as repressors of FTin annual plants. Yet, the pathway itself is conserved with the pathway regulating GPA in annual plants, a completely different process during the plant life cycle. Our research highlights both the conserved roles and functional diversities of AP2Ls in a more general balancing of meristem proliferation and arrest in perennial plants, providing insights into the evolutionary adaptation of growth regulation mechanisms across plant species
A nonsense mutation in the PRKG2 gene in dalmatian dogs with chondrodysplasia
No full textSkeletal dysplasias encompass a diverse group of genetic disorders characterized by short stature and dwarfism. In humans, 771 types of skeletal dysplasia have been documented. Similar forms of these disorders have also been observed in dogs. The first cases of documented skeletal dysplasia in Dalmatian dogs were reported in the early 1980s, with additional affected dogs observed in subsequent years. Careful radiological and histopathological examinations at the time revealed severe limb deformities, including shortened radii and ulnae, irregular growth plates and disrupted endochondral ossification. In this study, we applied whole-genome sequencing on samples collected in 1992 and identified a genetic variant in the PRKG2 gene, introducing a premature stop codon (XM_038582312: c.1601T > G, p.L534X). Genetic variants in PRKG2 have previously been implicated in human acromesomelic dysplasia, a disorder affecting limb growth in young children. The PRKG2-encoded protein plays a crucial role in endochondral ossification, and if translated, the identified nonsense variant would result in a truncated protein lacking most of the catalytic domain. Extended screening of the genetic variant revealed its continued segregation in the current Dalmatian population. Furthermore, three recent cases of dwarfism in Dalmatians were found to be homozygous for the identified PRKG2 nonsense variant. These findings provide compelling evidence for the role of PRKG2 in Dalmatian dwarfism, resolving a decades-old genetic mystery in the breed
Carbon sequestration potential from sustainable management of arable land in the EU
No full textCarbon sequestration in arable soils is gaining increasing attention in global policymaking initiatives for climate-change mitigation. Large-scale assessments of soil organic carbon development in arable land are affected by the scarcity of reliable time series of soil organic carbon monitoring data and often fail to replicate observed trends or appreciate any effects induced by changes in soil management. This study quantifies C loss from contemporary soil management on specialist crop farms in the EU and the potential societal benefits from C sequestration and avoided C loss due to improved management. Our analysis is based on an evidence pool of 214 independent long-term time series of soil organic carbon measurements spanning a wide range of climatic conditions and soil types, and considers the implementation of reduced tillage, organic amendments, soil cover during winter, and crop rotations. Overall, we estimate the potential for C sequestration from improved soil management on specialist crop farms, representing 40% of all the arable land in the EU, to be 48 ( +/- 15) million tonnes CO2 equivalents yearly, which corresponds to 17% ( +/- 8) of the target for additional carbon removals in the soil and forest sinks under the Fit for 55 package. In addition, our results show high spatial variability in C losses due to current soil management practices and potential C sequestration from improvements. The annual climate-change mitigation value per unit of land with improved management shows a four-fold variation across countries, with Finland exhibiting the highest value and Cyprus the lowest. This demonstrates that a C payment eco-scheme should be adjusted spatially to achieve cost-effective soil organic carbon sequestration in arable soils in the EU
Life in the dead: Biodiversity in dead wood along macro- and microclimatic gradients
Get PDFClimate is a major driver of biodiversity at both large and small spatial scales. My research focuses on the diversity of saproxylic (= dead wood dependent) species across macro- and microclimatic gradients in both forested and urban areas. I sampled beetles, fungi, and bacteria from spruce logs placed out in production forests along a 1200 km latitudinal gradient in Sweden, and along shade gradients from sun-exposed to fully shaded logs. I also measured the decomposition rates of these logs. Additionally, I surveyed saproxylic beetles in wood mould boxes, which resemble hollow trees, along urban-rural gradients in six cities in southern Sweden. For beetles and bacteria, I found a latitudinal diversity gradient with a higher diversity in the south. Moreover, the diversity of saproxylic beetles and brown-rot fungi (a key functional group in decomposition) followed the “hydroclimatic compensation model”. This model suggests that the species’ habitat requirements can alter along a regional climatic gradient to maintain consistent microclimatic conditions. For brown-rot fungi, I found a positive relationship between fungal diversity and saproxylic beetle abundance, which indicates that beetles serve as dispersal vectors. Furthermore, I observed increasing decomposition rates with increasing regional temperature. Interestingly, in the south, high fungal diversity reduced decomposition rates – likely due to antagonistic interactions – especially when the diversity of nitrogen-fixing bacteria was high. In contrast, this effect was reversed in the north under the same conditions. In urban landscapes, saproxylic beetle diversity was positively associated with habitat amount, but negatively associated with dispersal barriers, such as roads and buildings. Generally, I found microclimate to be a strong driver for the saproxylic biodiversity. Therefore, I conclude that dead wood creation with varying microclimatic conditions is needed to promote saproxylic species with different thermal requirements, both in forests and urban areas
The Effects of Forest Harvesting on Total and Methylmercury Concentrations in Surface Waters Depend on Harvest Practices and Physical Site Characteristics
Get PDFForest harvesting can lead to mercury (Hg) mobilization from soils to aquatic habitats and promote the transformation of inorganic Hg to highly neurotoxic and bioaccumulative methyl-Hg (MeHg). Multiple past studies reveal broad variation of stream water MeHg and total Hg (THg) concentration responses to forest harvesting, which has confounded messaging to forest and resource managers. To advance beyond divergent and sometimes contradictory findings, we synthesized information for 23 previously studied catchments in North America and Fennoscandia and compiled a uniform set of soil, landscape, and harvesting properties to identify forest management, riparian, and hillslope factors that influence responses of stream water MeHg and THg concentrations. From this synthesis, we found catchments with high soil moisture and organic soil layers >100 cm to be at highest risk for disturbance-induced increases in MeHg formation after harvest but not necessarily affecting concentrations of MeHg in stream waters. Instead, the combination of MeHg formation in soils along with factors that affect mobilization with runoff to streams most influenced how forest harvest affects MeHg concentrations in stream waters
On-farm testing of reduced animal welfare demands on productivity and welfare in pig production
Get PDFBackgroundSwedish animal welfare requirements exceed those of EU, which may have contributed to decreased pig production in Sweden since joining EU. On request from stakeholders, the Swedish Board of Agriculture allowed testing effects of reduced welfare demands on pig production for one year. This included weaning before 28 days at individual level, temporary confinements of sows during farrowing and mating, and increased stocking density of growers. The intervention period lasted for one year, and the productivity was compared with the preceding year.ResultsA reduced mean weaning age from 32 to 27 days did not have a significant effect on piglet welfare measures but the annual number of piglets weaned per sow increased by 1.3. Temporary confinement of sows at farrowing had no significant effect on piglet mortality or productivity, but the confinement reduced sow welfare. Temporary confinement of sows during mating did not improve sow productivity. Instead, hygiene and welfare decreased due to the confinement. Decreased stocking density by 10% compared with Swedish requirements had no significant effect on welfare measures. Nor did weight gain differ from the previous year. However, increased batch size of fatteners increased the incidence of respiratory lesions at slaughter, impaired growth and feed conversion.ConclusionsSimulations assured that over 90% of the piglets were older than 25 days in batches weaned at a mean age of 28 days. As piglets mature from three to four weeks of age, this was important for piglet welfare. Short-term confinement of sows at farrowing or mating decreased sow welfare due to the confinement while no significant increase in piglet productivity was found. An increased stocking density by 10% of weaners and growers did not affect welfare measures but increased the number of potential disease transmissions between pigs by 22% due to increased batch sizes. When batch size increased, respiratory lesions at slaughter increased and productivity decreased. Based on the results, the Board of Agriculture allowed herds to wean at a mean age of 28 days provided they complied with special requirements. Except for this, the minimal legal requirements of pig welfare in Sweden remained unchanged
A method to isolate soil organic phosphorus from other soil organic matter to determine its carbon isotope ratio
Get PDFDespite the importance of soil organic phosphorus (OP) for plant nutrition, its dynamics in soil remain elusive due to the lack of multiple stable P isotopes. Here, we developed a method that isolates the soil OP pool from other soil organic matter to measure its carbon isotope signature to elucidate soil OP decomposition. We tested three extractants (H2SO4, HCl, and NaOH in 0.5 M) for their capacity to preferentially extract OP. For isolating OP from the extract, we evaluated different pH adjustments (pH 1.5-10) and iron-or aluminum hydroxide additions. Finally, we determined the carbon isotope ratio (S13C) of the isolated OP pool. We found that the H2SO4 extracts had the highest OP content and the lowest organic carbon (OC):OP ratio compared to the HCl and NaOH extracts. The pH adjustments of the H2SO4 extracts to pH 4-7.5 removed >= 93 % of the extracted OP from the solution. The OC:OP ratio of the precipitates was the lowest (11-16) at pH 7.5, showing a strong preferential OP precipitation caused by the pH alteration. Metal hydroxide addition (combined with pH treatment) did not improve the preferential OP removal. The S13C of the OP reflected differences in the vegetation (C3/C4) that grows at the soil sampling sites. Overall, this method provides a simple and effective approach to isolate the soil OP pool from other soil organic matter and determine its carbon isotope ratio, which opens new avenues to study soil OP dynamics
Interactive and unimodal relationships between plant biomass, abiotic factors, and plant diversity in global grasslands
Get PDFGrasslands cover approximately a third of the Earth's land surface and account for about a third of terrestrial carbon storage. Yet, we lack strong predictive models of grassland plant biomass, the primary source of carbon in grasslands. This lack of predictive ability may arise from the assumption of linear relationships between plant biomass and the environment and an underestimation of interactions of environmental variables. Using data from 116 grasslands on six continents, we show unimodal relationships between plant biomass and ecosystem characteristics, such as mean annual precipitation and soil nitrogen. Further, we found that soil nitrogen and plant diversity interacted in their relationships with plant biomass, such that plant diversity and biomass were positively related at low levels of nitrogen and negatively at elevated levels of nitrogen. Our results show that it is critical to account for the interactive and unimodal relationships between plant biomass and several environmental variables to accurately include plant biomass in global vegetation and carbon models
Profiling of the microRNA transcriptome in feline whole blood
Get PDFCirculating microRNAs (miRNAs) are potential biomarkers for numerous diseases. Characterization of the whole blood (WB) miRNA-transcriptome (miRNome) in cats is lacking, which limits the potential use of miRNAs as biomarkers for diseases such as feline cardiovascular disease. The aims of the present study were to profile and evaluate circulating miRNAs in feline WB by high-throughput sequencing of the total miRNome in WB from twelve domestic mixed breed (DOM) and Norwegian Forest (NFO) cats stringently diagnosed with or without preclinical hypertrophic cardiomyopathy (HCM). A total of 459 mature miRNAs were identified in feline WB, of which 40 were potential novel feline miRNAs. A majority, 85.3%, of the miRNAs showed sequence similarity with human miRNAs. An effect of breed was found, with up to thirteen WB miRNAs being differentially abundant between breeds. The majority of the significant breed-specific miRNAs in feline WB could be associated with regulation of haematopoietic cells. One miRNA, miR-204-5p, was potentially associated with preclinical HCM in NFO cats, but the results need to be confirmed in a larger and sex-unbiased cohort. In conclusion, here we used miRNome-sequencing to identify hundreds of circulating miRNAs in feline WB. Breed should be considered when evaluating the miRNome in feline WB
Chironomid-climate continentality conundrum
Get PDFIt is predicted that continentality, a climate parameter representative of a region's annual temperature and precipitation range, will undergo significant changes in the future. The lack of past continentality reconstructions makes it impossible to decipher any long-term patterns of continentality changes. Here, we investigate the extent to which continentality influences modern chironomid assemblages and evaluate their ecological relevance for palaeolimnological data-based reconstructions of past continentality. We selected 53 lakes along a longitudinal gradient covering the East European Plain (Western part of Russia, Estonia, Latvia) and southern Scandinavia (Sweden and Norway). We analysed the dependency of chironomid assemblages on a variety of environmental parameters including two continentality indices (annual temperature range (ATR) and the Kerner Oceanity Index (KOI)), growing degree days at base temperature 5 degrees C, mean air temperatures of July, April, and October, number of ice-cover days, lake-water pH, loss-of-ignition and water depth using redundancy analysis. Correlations between all variables were tested to check for possible confounding effects. KOI had the highest explanatory power of 18.4% in the dataset and an absence of collinearity (correlation index < 0.7) with all the other tested variables. Further, we estimated weighted average optima to investigate the distribution of the morphotypes along the continentality gradient in the dataset. Glyptotendipes pallens-type, Neozavrelia, Polypedilum sordens-type, and Microchironomus showed a preference for a continental climate, while Paratanytarsus penicillatus-type, Pseudorthocladius, Thienemannimyia, and Limnophyes were found mainly in samples from oceanic areas. Weighted averaging-partial least squares regression was used for a trial test of the data, resulting in a promising KOI-based model performance with R2 = 0.73 and RMSEP = 5.1. Despite the relatively small dataset, our study suggests that chironomid data have the potential for further development as a tool for reconstructing palaeocontinentality