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| 2. |
- Bargaz, Adnane, et al.
(författare)
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Intercropping of faba bean with wheat under low water availability promotes faba bean nodulation and root growth in deeper soil layers
- 2015
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Ingår i: Procedia Environmental Sciences. - : Elsevier BV. - 1878-0296. ; 29, s. 111-112
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Konferensbidrag (refereegranskat)abstract
- The symbiotically fixed N is advantageous to legumes growing under N-limiting conditions, and is also potentially beneficial for subsequent or associated non-legume crops(1, 2). However, under stressful conditions such as water limitation and low nutrient availability, legumes may lose the distinct advantage of an unlimited source of symbiotic N-2 (3, 4,) (5) Belowground niche complementarity in legume-cereal intercrops may improve resource use efficiency and adaptability to environmental constraints, but effects of water limitation on legume rooting and nodulation patterns is poorly understood. To advance our knowledge of mechanisms involved in water stress response, faba bean (Vicia faba L., FB) and wheat (Triticum aestivum L.) were grown as mono- and intercrops in soil-filled plexiglass rhizoboxes under water sufficiency (80% of field capacity; FC) and water stress (30% of FC). Water stress decreased shoot biomass in both monocropped and intercropped FB, as well as root length in monocropped FB. Intercropping increased both shoot dry weight and height of FB irrespective of water treatment, while increased root biomass and length in intercropped FB was observed only under water stress. No significant effects of crop or water treatment were found on wheat growth parameters. Intercropping increased overall nodulation (nodule number and nodule dry weight; NDW) regardless of water availability. However spatial patterns of nodulation differed between water treatments: top-15-cm NDW and number increased (27 and 33%, respectively) in sufficiently-watered intercropped FE, while NDW in the same soil layer significantly decreased (45%) in water-stressed intercropped FE. In contrast, below-15-cm NDW and number significantly increased in intercropped FE under both water levels. This enhanced nodulation in the deeper soil layer and the associated increase in root and shoot growth provides evidence for a shift in niche occupancy that improves FB performance when exposed to water limitation in intercropping. (C) 2015 The Authors. Published by Elsevier B.V.
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| 3. |
- Bargaz, Adnane, et al.
(författare)
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Nodulation and root growth increase in lower soil layers of water-limited faba bean intercropped with wheat
- 2016
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Ingår i: Journal of Plant Nutrition and Soil Science. - : Wiley. - 1436-8730 .- 1522-2624. ; 179, s. 537-546
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Tidskriftsartikel (refereegranskat)abstract
- Below-ground niche complementarity in legume-cereal intercrops may improve resource use efficiency and root adaptability to environmental constraints. However, the effect of water limitation on legume rooting and nodulation patterns in intercropping is poorly understood. To advance our knowledge of mechanisms involved in water-limitation response, faba bean (Vicia faba L.) and wheat (Triticum aestivum L.) were grown as mono- and intercrops in soil-filled plexiglass rhizoboxes under water sufficiency (80% of water-holding capacity) and water limitation (30% of water-holding capacity). We examined whether intercropping facilitates below-ground niche complementarity under water limitation via interspecific root stratification coupled with modified nodulation patterns. While no significant treatment effects were measured in intercropped wheat growth parameters, water limitation induced a decrease in shoot and root biomass of monocropped wheat. Likewise, shoot biomass and height, and root length of monocropped faba bean significantly decreased under water limitation. Conversely, water limitation stimulated root biomass of intercropped faba bean in the lower soil layer (15-30 cm soil depth). Similarly, total nodule number of faba bean roots as well as nodule number in the lower soil layer increased under intercropping regardless of water availability. Under water limitation, intercropping also led to a significant increased nodule biomass (48%) in the lower soil layer as compared to monocropping. The enhanced nodulation in the lower soil layer and the associated increase in root and shoot growth provides evidence for a shift in niche occupancy when intercropped with wheat, which improves water-limited faba bean performance.
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| 4. |
- Bargaz, Adnane, et al.
(författare)
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Phosphorus Use Efficiency for N2 Fixation in the Rhizobial Symbiosis with Legumes
- 2015
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Ingår i: Biological Nitrogen Fixation. - Hoboken, NJ, USA : John Wiley & Sons, Inc. - 9781118637043 ; , s. 455-464
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Symbiotic nitrogen fixation (SNF) by legumes may provide an ecologically acceptable complement or substitute for mineral nitrogen fertilizers that farmers try to minimize for economic limitation and environment sake. However, phosphorus (P) deficiency is a major limiting factor for legume–rhizobia symbioses, particularly in acidic and calcareous soils. Nevertheless, the expression of legume SNF potential under P deficiency may be improved. Indeed genotypes contrasting in P use efficiency (PUE) for SNF could be found for such legumes spp. asPhaseolus vulgaris,Vigna unguiculata, orMedicago truncatulain hydroaeroponic culture under glasshouse conditions after inoculation with specific reference rhizobia. In order to assess the contribution of phosphatase activity to PUE for SNF, anin situRT-PCR methodology was used to localize and quantify the mRNA of candidate genes in nodules of common bean grown under deficient versus sufficient P supply. The transcript localization of phytase, phosphoenolpyruvate phosphatase, and trehalose 6 phosphate phosphatase was found to be tissue specific and differ among any phosphatase APase genes, P treatments, and legume genotypes. In order to assess whether the genotypic difference in PUE for SNF may contribute to adaptation of the rhizobial symbiosis to low-P soils, the nodulation and growth of contrasting common-bean recombinant lines from the cross of BAT477 and DOR364 were assessed in fields of farmers in reference agroecosystems of the Mediterranean basin following a participatory approach. The most efficient genotype, namely RIL115, was superior in most fields where nodulation was above the threshold for significant contribution to legume nutrition. From those fields with low-P soils where adaptation was observed for low-efficiency genotypes, bacteria were isolated from nodules and rhizosphere in order to search for rhizobia or rhizobacteria that could increase the P efficiency for the legume symbiosis. Since mycorrhizae may contribute to the PUE, the tripartite symbiosis was tested in hydroaeroponic culture, showing that some species may limit nodulation by contrast withGlomus intradicesthat increased it under P deficiency. It is concluded that (i) phosphatases contribute to the use of organic P for N2fixation and to the increase in nodule permeability to O2under P deficiency; (ii) nodulation in agroecosystems varies considerably in space and time; (iii) high PUE for SNF may increase the N2-dependent growth of common bean in low-P soils and the overall P bioavailability; and (iv) some local rhizobia may contribute to the PUE for SNF.
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| 5. |
- Bargaz, Adnane, et al.
(författare)
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Physiological and Molecular Aspects of Tolerance to Environmental Constraints in Grain and Forage Legumes
- 2015
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 16, s. 18976-19008
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Forskningsöversikt (refereegranskat)abstract
- Despite the agronomical and environmental advantages of the cultivation of legumes, their production is limited by various environmental constraints such as water or nutrient limitation, frost or heat stress and soil salinity, which may be the result of pedoclimatic conditions, intensive use of agricultural lands, decline in soil fertility and environmental degradation. The development of more sustainable agroecosystems that are resilient to environmental constraints will therefore require better understanding of the key mechanisms underlying plant tolerance to abiotic constraints. This review provides highlights of legume tolerance to abiotic constraints with a focus on soil nutrient deficiencies, drought, and salinity. More specifically, recent advances in the physiological and molecular levels of the adaptation of grain and forage legumes to abiotic constraints are discussed. Such adaptation involves complex multigene controlled-traits which also involve multiple sub-traits that are likely regulated under the control of a number of candidate genes. This multi-genetic control of tolerance traits might also be multifunctional, with extended action in response to a number of abiotic constraints. Thus, concrete efforts are required to breed for multifunctional candidate genes in order to boost plant stability under various abiotic constraints.
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| 6. |
- Bargaz, Adnane, et al.
(författare)
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Species interactions enhance root allocation, microbial diversity and P acquisition in intercropped wheat and soybean under P deficiency
- 2017
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Ingår i: Applied Soil Ecology. - : Elsevier BV. - 0929-1393 .- 1873-0272. ; 120, s. 179-188
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Tidskriftsartikel (refereegranskat)abstract
- Belowground interactions in grain legume-cereal intercrops may improve resource acquisition and adaptation to environmental constraints such as phosphorus (P) deficiency. To advance the knowledge of belowground facilitative mechanisms involved in P-deficiency tolerance (root allocation, biochemical and microbial responses), soybean (Glycine max) and wheat (Triticum aestivum) were grown as monocrops and intercrops under P-deficiency and P-sufficiency conditions in soil-filled rhizoboxes. The hypothesis was that intercropping stimulates root microbial diversity, root biomass allocation and P-hydrolyzing acid phosphatases (APase) activity in roots under P-deficient conditions. Total root dry weight (RDW), length, and surface area significantly increased in P-deficient intercropped wheat and soybean. Greater root allocation to deeper soil layers was evident for P-deficient intercropped wheat. Shallow roots of intercropped wheat exhibited highly stimulated APase activity under P-deficient conditions while shallow roots of monocropped soybean exhibited higher APase activity in comparison to deeper roots, irrespective of P treatment. Root fungal diversity was significantly (p < 0.05) higher in intercropped wheat, and was significantly correlated with RDW, root APase activity, shoot P, and soil available P (rho = 0.24, p= 0.01). Root bacterial diversity was higher in both intercrops, and was significantly correlated with RDW and shoot N concentration. The observed shifts in root microbial diversity, root biomass allocation and APase activity provide explanatory mechanisms of relationships between rhizosphere heterogeneity and pathways for increased P acquisition in diversified crops. Advanced belowground metabolomics on root microbial communities are required to reveal the beneficial effect of root microorganisms in associations of different crop species.
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| 7. |
- Bentham, James, et al.
(författare)
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A century of trends in adult human height
- 2016
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Ingår i: eLIFE. - 2050-084X. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in South Korean women and Iranian men, who became 20.2 cm (95% credible interval 17.522.7) and 16.5 cm (13.319.7) taller, respectively. In contrast, there was little change in adult height in some sub-Saharan African countries and in South Asia over the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8144.8). The height differential between the tallest and shortest populations was 19-20 cm a century ago, and has remained the same for women and increased for men a century later despite substantial changes in the ranking of countries.
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| 8. |
- Bentham, James, et al.
(författare)
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A century of trends in adult human height
- 2016
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Ingår i: eLIFE. - : eLife Sciences Publications Ltd. - 2050-084X. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in South Korean women and Iranian men, who became 20.2 cm (95% credible interval 17.5–22.7) and 16.5 cm (13.3– 19.7) taller, respectively. In contrast, there was little change in adult height in some sub-Saharan African countries and in South Asia over the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8– 144.8). The height differential between the tallest and shortest populations was 19-20 cm a century ago, and has remained the same for women and increased for men a century later despite substantial changes in the ranking of countries.
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| 9. |
- Brehm, Nadine, et al.
(författare)
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A Genetic Mouse Model of Parkinson’s Disease Shows Involuntary Movements and Increased Postsynaptic Sensitivity to Apomorphine
- 2015
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Ingår i: Molecular Neurobiology. - : Springer Science and Business Media LLC. - 0893-7648 .- 1559-1182. ; 52:3, s. 1152-1164
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Tidskriftsartikel (refereegranskat)abstract
- Alpha-synuclein (SNCA) protein aggregation plays a causal role in Parkinson's disease (PD). The SNCA protein modulates neurotransmission via the SNAP receptor (SNARE) complex assembly and presynaptic vesicle trafficking. The striatal presynaptic dopamine deficit is alleviated by treatment with levodopa (L-DOPA), but postsynaptic plastic changes induced by this treatment lead to a development of involuntary movements (dyskinesia). While this process is currently modeled in rodents harboring neurotoxin-induced lesions of the nigrostriatal pathway, we have here explored the postsynaptic supersensitivity of dopamine receptor-mediated signaling in a genetic mouse model of early PD. To this end, we used mice with prion promoter-driven overexpression of A53T-SNCA in the nigrostriatal and corticostriatal projections. At a symptomatic age (18 months), mice were challenged with apomorphine (5 mg/kg s.c.) and examined using both behavioral and molecular assays. After the administration of apomorphine, A53T-transgenic mice showed more severe stereotypic and dystonic movements in comparison with wild-type controls. Molecular markers of extracellular signal-regulated kinase 1 and 2 (ERK1/2) phosphorylation and dephosphorylation, and Fos messenger RNA (mRNA), were examined in striatal tissue at 30 and 100 min after apomorphine injection. At 30 min, wild-type and transgenic mice showed a similar induction of phosphorylated ERK1/2, Dusp1, and Dusp6 mRNA (two MAPK phosphatases). At the same time point, Fos mRNA was induced more strongly in mutant mice than in wild-type controls. At 100 min after apomorphine treatment, the induction of both Fos, Dusp1, and Dusp6 mRNA was significantly larger in mutant mice than wild-type controls. At this time point, apomorphine caused a reduction in phospho-ERK1/2 levels specifically in the transgenic mice. Our results document for the first time a disturbance of ERK1/2 signaling regulation associated with apomorphine-induced involuntary movements in a genetic mouse model of synucleinopathy. This mouse model will be useful to identify novel therapeutic targets that can counteract abnormal dopamine-dependent striatal plasticity during both prodromal and manifest stages of PD.
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| 10. |
- Carlsson, Georg, et al.
(författare)
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Artrika vallar ger hållbar energiråvara och gynnar den biologiska mångfalden
- 2015
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Ingår i: LTV-fakultetens faktablad.
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Annan publikation (populärvet., debatt m.m.)abstract
- Detta faktablad utgör slutrapport för projektet "Användning av outnyttjade gräsmarker för biodiversitet och bioenergi - nätverk och fältförsök", som har genomförts under 2011-2014. Projektet har fört samman många aktörer med intresse för jordbruk, naturvård och bioenergi, och visat att nyetablering och extensiv hävd av artrika vallar kan generera värdefulla synergieffekter mellan minskad klimatpåverkan, minskad övergödning och ett rikt odlingslandskap.
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