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Plant organic nitrogen nutrition: costs, benefits, and carbon use efficiency
Get PDFDifferences in soil mobility and assimilation costs between organic and inorganic nitrogen (N) compounds would hypothetically induce plant phenotypic plasticity to optimize acquisition of, and performance on, the different N forms. Here we evaluated this hypothesis experimentally and theoretically. We grew Arabidopsis in split-root setups combined with stable isotope labelling to study uptake and distribution of carbon (C) and N from l-glutamine (l-gln) and NO3- and assessed the effect of the N source on biomass partitioning and carbon use efficiency (CUE). Analyses of stable isotopes showed that 40-48% of C acquired from l-gln resided in plants, contributing 7-8% to total C of both shoots and roots. Plants grown on l-gln exhibited increased root mass fraction and root hair length and a significantly lower N uptake rate per unit root biomass but displayed significantly enhanced CUE. Our data suggests that organic N nutrition is linked to a particular phenotype with extensive growth of roots and root hairs that optimizes for uptake of less mobile N forms. Increased CUE and lower N uptake per unit root growth may be key facets linked to the organic N phenotype
Carbon Credits Through Wood Use: Revisiting the Maximum Potential and Sensitivity to Key Assumptions
Get PDFWood use generates technosphere carbon credits (TCCs) through avoided fossil-based emissions and net sequestration of carbon into the technosphere (harvested wood products and geological storage). We investigated how large and uncertain TCCs of wood use per carbon harvested are considering the current and alternative ways of using wood, and the effects of the decarbonization of societies over 25-, 50-, and 100-year time horizons. We applied stochastic simulation and scenario analysis using Finnish market structure as a baseline to demonstrate the use of the TCC calculator created. The mean value of TCCs of wood use were between 0.2 and 0.5 tC/tC with an uncertainty range from 0.1 to 0.8 tC/tC, depending on the scenario. The uncertainties were mainly concerned with the extent to which (1) fossil-based emissions are avoided through substitution (displacement factors) and (2) fossil-based raw materials are substituted (substitution rates). Assumptions on the decarbonization of societies reduced TCCs of wood use significantly over time. TCCs of wood use can be increased by directing wood into uses that substitute fossil-intensive materials and have a long lifetime, such as construction materials, and increasing energy recovery and avoiding emitting carbon at the end of life of harvested wood products by carbon capture and storage. However, they were very likely to be considerably lower than forest carbon debits resulting from harvesting additional wood for substitution under all considered circumstances and under a wide but reasonable range of stochastic parameter values. Thus, the result emphasizes the need to reduce overall consumption of goods to mitigate climate change
The type of environment has a greater impact on the larval microbiota of Anopheles arabiensis than on the microbiota of their breeding water
Get PDFMosquito larvae of the genus Anopheles develop entirely in water, frequently visiting the surface for air. The aquatic environment plays a key role in shaping their microbiota, but the connection between environmental characteristics of breeding sites and larval microbiota remains underexplored. This study focuses on Anopheles arabiensis, which inhabits the surface microlayer (SML) of breeding sites, a zone with high particle density. We hypothesized that the SML could allow us to capture the diversity of the surrounding environment, and in turn its influence on the larval microbial communities. To test this, we collected A. arabiensis larvae and SML samples from various breeding sites categorized by environmental features. Our results confirm that breeding site characteristics are significant drivers of the bacterial species present in mosquito larvae. Additionally, we found that the larval micro-environment selectively shapes its microbiota, highlighting a dynamic interplay between environmental and internal factors. Interestingly, specific bacterial families were associated with the presence or absence of larvae in breeding sites, suggesting potential ecological roles. These findings expand our understanding of vector-mosquito microbiota, emphasizing the importance of breeding site features in shaping larval microbial communities and providing a foundation for future research on mosquito ecology and control strategies.Environmental characteristics of the breeding site are an important factor in shaping the microbiota of mosquitoes of the genus Anopheles
Profiling host- and parasite-derived miRNAs associated with Strongylus vulgaris infection in horses
Get PDFThe equine bloodworm, Strongylus vulgaris, is a common and highly pathogenic parasite in horses due to its migratory life cycle involving the intestinal arteries. Current diagnostic techniques cannot detect the prepatent migrating stages of S. vulgaris, highlighting the need for new biomarkers. Parasites release microRNAs (miRNAs) into their environment, which could potentially be detectable in host blood samples. Additionally, host miRNA expression patterns may change in response to infection. This study aimed to identify miRNAs associated with S. vulgaris infection by profiling the horse's miRNA response in the larval predilection site, the Cranial Mesenteric Artery (CMA) and examining the circulating parasite and horse-derived miRNAs in plasma of S. vulgaris-infected horses. Plasma samples were collected from 27 horses naturally infected with S. vulgaris and 28 uninfected horses. Arterial tissue samples from the CMA and Aorta were collected from a subset (n = 12) of the infected horses. Small RNA sequencing (small RNAseq) of a subset of the plasma samples (n = 12) identified miRNAs of interest, followed by quantitative real-time PCR (qPCR) evaluation of selected miRNAs in plasma from a larger cohort of horses. Small RNAseq detected 138 parasite-derived and 533 horse-derived miRNAs in the plasma samples. No difference in parasite-derived miRNA abundance was found between the infected and uninfected horses, but 140 horse-derived miRNAs were significantly differentially abundant between the two groups. When evaluated by qPCR, none of the selected parasite-derived miRNAs were detectable in plasma, but seven horsederived miRNAs were confirmed differentially abundant in plasma between the two groups. Seven horsederived miRNAs were differentially expressed in CMA tissue affected by migrating S. vulgaris compared with unaffected aortic tissue, with Eca-Mir-223-3p (Log2FC: 4.74) and Eca-Mir-140-3p (Log2FC: -3.64) being most differentially expressed. A receiver operating characteristic curve analysis suggested that Eca-Mir-486-5p and Eca-Mir-140-3p had the best diagnostic performance for distinguishing between infected and uninfected horses, with areas under the curve (AUC) of 0.78 and 0.77, respectively. Notably, Eca-Mir-140-3p was associated with age, and correcting for interaction with age increased the AUC to 0.96. In conclusion, several horse-derived miRNAs were associated with S. vulgaris infection and could differentiate between infected and uninfected horses based on their plasma abundance. However, the levels of these miRNAs were influenced by other factors (i.e age, breed), complicating their use as biomarkers. Parasite-derived miRNA abundance did not differ between S. vulgaris infected horses and those infected with other parasites using small RNAseq and were below detection limits of qPCR
Species distribution models built with local species data perform better for current time, but suffer from niche truncation
Get PDFTo cope with climate change-induced alterations, forest ecosystems' conservation and restoration require models that are both capable to incorporate current local-scale dynamics but also to anticipate future changes. These requirements may be fulfilled by robust assessments of response (i.e., species data such as forest inventories) and predictor (e.g., climate) variables. The aim of this study is to predict current and future probability of occurrence for 22 tree species comparing inventory and climate data at different spatial scales and test for model performance, reliability, and niche truncation. We built species distribution models (SDMs) for 22 tree species of Piedmont, an Alpine administrative region of north-western Italy. We compared (i) a fine-scale model calibrated with a local forest inventory with a 250-m spatial resolution at the extent of Piedmont and a regional climate model calibrated on the Italian extent versus (ii) coarse-scale model calibrated with a pan-European forest inventory (EU-Forest) at 1-km resolution and a global climate dataset (CHELSA v1.2). Moreover, (iii) we developed a data pooling method by combining the species data and using CHELSA. We evaluated models using spatial-block cross-validation and external validation through several metrics. We predicted the probability of occurrence for current and future under RCP4.5 and RCP8.5 climate scenarios. Models built with local species data performed better for the future than those incorporating broad species data and their current predictions reflected the realized distribution of species but they suffered from niche truncation while extrapolated to the future. Indeed, models calibrated at the local scale predicted greater magnitude of changes for future scenarios compared to coarse-scale models. Integrating species data at different extents and resolutions is a valid approach when both are available
Priority actions for Fusarium head blight resistance in durum wheat: Insights from the wheat initiative
Get PDFFusarium head blight (FHB), mainly caused by Fusarium graminearum and Fusarium culmorum, is a major wheat disease. Significant efforts have been made to improve resistance to FHB in bread wheat (Triticum aestivum), but more work is needed for durum wheat (Triticum turgidum spp. durum). Bread wheat has ample genetic variation for resistance breeding, which can be readily exploited, while durum wheat is characterized by higher disease susceptibility and fewer valuable resistance sources. The Wheat Initiative - Expert Working Group on Durum Wheat Genomics and Breeding has promoted a scientific discussion to define the key actions that should be prioritized for achieving resistance in durum wheat comparable to that found in bread wheat. Here, a detailed state of the art and novel tools to improve FHB resistance in durum are presented, together with a perspective on the next steps forward. A meta-analysis grouping all quantitative trait loci (QTL) associated with FHB resistance in both bread and durum wheat has been conducted to identify hotspot regions that do not overlap with Rht alleles, which are known to negatively correlate with FHB resistance. A detailed list of QTL related to FHB resistance and deoxynivalenol contamination and durum lines carrying different sources of FHB resistance are provided as a strategic resource. QTL, closely linked markers and durum wheat lines carrying the useful alleles, can be selected to design an effective breeding program. Finally, we highlight the priority actions that should be implemented to achieve satisfactory resistance to FHB in durum wheat
Spatial and temporal variation in crop productivity and relation with soil fertility within upland agroforestry
Get PDFAgroforestry can be an option of sustainable farming practices for upland communities. However, information of spatial and temporal variation in soil fertility and crop productivity along slopes, which can guide e.g. effective management, such as application of fertilizers, is limited. This study evaluated spatial and temporal variability in crop productivity and soil fertility along slopes in two different fruit tree agroforestry systems in upland areas of north-west Vietnam: (1) longan-mango agroforestry integrating longan (Dimocarpus longan L.), mango (Mangifera indica L.), maize (Zea mays L.), and guinea grass (Panicum maximum Jacq.), and (2) plum agroforestry integrating plum (Prunus salicina L.), maize, and guinea grass. The two systems were established on relatively steep slopes, 37 % and 65 % slope, respectively. Crop performance and soil fertility were measured in different positions relative to the fruit tree-grass rows over 4–5 years and compared with sole-crop maize. The results showed that maize height, grain yield, and leaf nitrogen (N) concentrations were significantly higher at the upslope than downslope side of tree-grass rows. For example, the grain yields were 30–35 % higher at the upslope than downslope side. Regarding soil fertility, there was a tendency that SOC, total N, total phosphorus (P), available P, and available potassium (K) were higher at the upslope than downslope side of tree-grass rows. Thus, the forage grass strips played an important role in trapping N and other nutrients, and enhanced nutrient use efficiency within agroforestry at the steeply sloping study sites. The maize performance and soil fertility in the areas mid-way between two tree-grass rows were comparable to those in sole-crop maize. The results of this study can provide guidance for farmers managing fruit tree agroforestry in north-west Vietnam or other regions with similar cropping, climate, and biophysical characteristics to implement more effective plot management practices on sloping land
Towards sustainable spring wheat cultivation
Get PDFNitrogen (N) is essential for plant growth; however, the frequent use of N-based fertilizers to maintain high crop yields is associated with several environmental risks. Sustainable agriculture requires crops that maintain high yields with less fertilizer. Spring wheat, a promising staple crop in Nordic regions, was used as a model to evaluate the breeding potential for N use efficiency traits, which are not typically targeted in crop breeding programs. The overall objective of this thesis was to explore the application of N use efficiency traits in spring wheat breeding programs for high latitude environments. The aims were to (i) explore the relationships between breeding target and non-target traits across various varieties grown in Central Sweden over a two year period; (ii) assess the genetic and environmental influences on early-vigor root traits; (iii) develop a methodology to rapidly assess N use efficiency traits; and (iv) identify genomic regions and candidate lines with desirable trait combinations in a population of 183 recombinant inbred lines (RILs). Stable associations were found between certain N use efficiency traits and breeding targets, as wheats bred for high yield were characterized by high N utilization efficiency. High N uptake efficiency was not linked to any breeding target. Early-vigor root traits were strongly influenced by both variety and environmental conditions, but unassociated with breeding target. A simple methodology for phenotyping N use efficiency traits in large populations was developed based on allometry, and promising candidate lines with favorable trait combinations were identified, along with 186 genomic regions associated with N use efficiency. The results demonstrate the potential of incorporating N use efficiency traits as breeding targets for crops, thereby supporting a more sustainable agricultur
The power of prevention and valorisation - Environmental impacts of reducing surplus and waste of bakery products at retail
Get PDFThe wastage of edible food still remains a major global challenge, despite its well-known consequences. Although bread and bakery products are identified as some of the most frequently wasted foods, the amounts generated and the pathways used to manage this surplus are often unknown. To support sustainable food systems, there is an urgent need to identify how much surplus is generated along the supply chain, including both sweet and savoury products, and to map how this resource is managed. The aim of this study was to quantify the surplus and waste of baked goods in Sweden, alongside mapping the pathways used for managing unsold bread generated at the supplier-retailer interface. Life cycle assessment, considering 16 midpoint indicators and three endpoint indicator, was used to assess the environmental benefits of reducing bakery product surplus. The results reveal that nearly 180 000 tonnes of baked goods are wasted annually in Sweden. Roughly 51% is generated at the supplier-retailer interface, particularly considering bread sold under take-back agreements where 14% of production becomes surplus. Only 2% of this surplus is recirculated to the food system, while the majority is instead used in energy production. Scenario analyses, including nine scenarios designed to capture various innovations to reduce surplus, demonstrated that prevention and valorisation strategies, such as data sharing and price reductions, have the greatest potential for reducing waste and environmental impact. Prevention could result in up to ten times lower climate impact per kg bread. The findings offer valuable insights for future research on sustainable food systems, and can act as practical guidance for industry actors, stakeholders, and policymakers to implement waste-reduction strategies that promote sustainable, resource-efficient food systems
Synergistic effects of biochar and abscisic acid improved root morphology, antioxidant defense system and decreased availability and bioaccumulation of cadmium in Triticum aestivum (L.) under cadmium stress
Get PDFBiochar (BC) and abscisic acid (ABA) may deliver positive physiological effects on heavy metal-stressed plants but their interactive role for regulating cadmium (Cd) availability in agricultural soils is unclear. This study revealed that the Cd-induced oxidative stress significantly reduced the growth of wheat, physiology and antioxidant responses. Interestingly, the co-application of BC (2.5 %) and ABA (20 μmol L−1) restored the growth of wheat plants by minimizing Cd accumulation and translocation than their single use. The co-application of these amendments significantly increased the tissues biomass by 36 %, total root volume (29 %), root surface area (44 %), foliar Chl-a and Chl-b by 59 % and 55 % at 10 mg kg−1 Cd than control. Elevated Cd levels increased the proline, MDA and H2O2 contents, while BC and ABA applications ameliorated the Cd-induced oxidative injury by boosting the enzymatic activities of catalase by 46 %, ascorbate-peroxidase by 46 % and peroxidase by 37 % at 10 mg kg−1 Cd. The Cd treatment also increased Cd levels in soil, root and shoot tissues of wheat plants. The co-application BC and ABA reduced DTPA-extractable soil Cd by about 3-fold at 5 mg kg−1 and by about 1.8-fold at 10 mg kg−1, as compared to respective controls. The combined BC + ABA treatment reduced Cd biological accumulation by 35 % and 33 %; and Cd translocation by 21 % and 9 % at 5 and 10 mg kg−1 Cd levels than control. It was concluded that the combined BC+ABA application restored the growth, physiology, antioxidant enzymatic activities and minimized Cd bioaccumulation in wheat tissues