8 research outputs found
Diurnal changes of Rubisco in response to elevated CO2, temperature and nitrogen in wheat grown under temperature gradient tunnels. Environ
Abstract Growth at elevated CO 2 and temperature often leads to decreased Rubisco activity. We investigated the effects of increased CO 2 , temperature and nitrogen on the diurnal changes in the control of ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco) activity in wheat (Triticum aestivum L.). Spring wheat was grown at ambient and 700 µmol mol -1 CO 2 , under ambient and 4 ºC warmer temperatures, and with two levels of nitrogen supply in field tunnels in a Mediterranean environment. At ear emergence, elevated CO 2 increased Rubisco activation, but decreased Rubisco protein and, with high nitrogen, Rubisco specific activity, and had no effect on th
Spread of a SARS-CoV-2 variant through Europe in the summer of 2020
[EN] Following its emergence in late 2019, the spread of SARS-CoV-21,2 has been tracked by phylogenetic analysis of viral genome sequences in unprecedented detail3,4,5. Although the virus spread globally in early 2020 before borders closed, intercontinental travel has since been greatly reduced. However, travel within Europe resumed in the summer of 2020. Here we report on a SARS-CoV-2 variant, 20E (EU1), that was identified in Spain in early summer 2020 and subsequently spread across Europe. We find no evidence that this variant has increased transmissibility, but instead demonstrate how rising incidence in Spain, resumption of travel, and lack of effective screening and containment may explain the variant’s success. Despite travel restrictions, we estimate that 20E (EU1) was introduced hundreds of times to European countries by summertime travellers, which is likely to have undermined local efforts to minimize infection with SARS-CoV-2. Our results illustrate how a variant can rapidly become dominant even in the absence of a substantial transmission advantage in favourable epidemiological settings. Genomic surveillance is critical for understanding how travel can affect transmission of SARS-CoV-2, and thus for informing future containment strategies as travel resumes.S
Diurnal changes of Rubisco in response to elevated CO2, temperature and nitrogen in wheat grown under temperature gradient tunnels.
Growth at elevated CO2 and temperature often leads to decreased Rubisco activity.
We investigated the effects of increased CO2, temperature and nitrogen on the
diurnal changes in the control of ribulose-1,5-bisphosphate carboxylase oxygenase
(Rubisco) activity in wheat (Triticum aestivum L.). Spring wheat was grown at
ambient and 700 μmol mol-1 CO2, under ambient and 4 ºC warmer temperatures, and
with two levels of nitrogen supply in field tunnels in a Mediterranean environment.
At ear emergence, elevated CO2 increased Rubisco activation, but decreased Rubisco
protein and, with high nitrogen, Rubisco specific activity, and had no effect on the
rbcS transcript. Warmer temperatures tended to decrease the rbcS mRNA level and
Rubisco protein, although the effect on Rubisco activity was small. High nitrogen
decreased Rubisco activation or specific activity, depending on the CO2
concentration. It increased Rubisco protein at the end of the night, but accelerated its
diurnal loss. The main changes after anthesis were the disappearance of the decrease
in Rubisco specific activity caused by elevated CO2, an increase in this activity with
above-ambient temperatures combined with high nitrogen, and that high temperature
and nitrogen did not affect Rubisco protein contents. This study suggests that
decreased leaf protein and increased levels of a Rubisco inhibitor, rather than gene
repression by sugars, are involved in acclimation to elevated CO2. High nitrogen
increases this down regulation. Changes during growth in levels of leaf metabolites
and protein may alter the relative importance of levels of inhibitors and Rubisco
amounts for Rubisco regulation.The technical cooperation of Libia Hernandez and Angel Verdejo is
acknowledged. The staff of the IRNASA experimental farm helped with crop sowing
and fertilizer application. The Northern blots analyses were made at the laboratory of
Prof. M. Stitt (Botanical Institute, University of Heidelberg, Germany) with Marina
Bueno CSIC-DFG funds granted to R. Morcuende. This work was funded by the
Spanish Plan Nacional de Investigación y Desarrollo (grant no. CLI96-0396). We
thank Dr. Christine Raines (Dept. of Biological Sciences, John Tabor Laboratories,
University of Essex, UK) for the generous gift of the Rubisco cDNA.Peer reviewe
Contrasting responses of photosynthesis and carbon metabolism to low temperatures in tall fescue and clovers.
Growth, photosynthesis and carbohydrate metabolism in plants of two grassland
species, clover (Trifolium subterra neum L. cv. Areces and Gaitan) and tall fescue
(Festuca arundinacea Schreb.), shifted from 25 to 12°C for 1 day or developed at 12°C
were compared with controls kept at 25°C. Cold development produced a larger
inhibition of growth in fescue than in clovers. In contrast, transferring plants from high
to low temperature inhibited photosynthesis to a lesser extent in fescue than in clovers,
this difference being associated with an increase in the activation state of Calvin cycle
enzymes in fescue, but not in the clovers, a decreased cytosolic fructose-1,6-
bisphosphatase (cFBPase, EC 3.1.3.11) activity in clovers, and an accumulation of
hexose phosphates only in fescue. Development at 12°C partly relieved the inhibition of
photosynthesis in clovers, in contrast with fescue, which correlated with increases in
total ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco, EC 4.1.1.39) activity
only in clovers, and with greater increases in total stromal FBPase (sFBPase) activity in
clovers than in fescue. The activity of sucrose synthesis enzymes was increased in the
two clovers and fescue developed in the cold, while carbohydrate accumulation was
much bigger in cold-developed fescue than in clovers because of a 5-fold increase in
fructan contents in the former. The contents of phosphorylated intermediates increased
in clovers but decreased in fescue grown at 12°C. Our results suggest that restricted
ribulose-1,5-bisphosphate (RuBP) regeneration limited the recovery of photosynthetic
capacity in cold-developed fescue.Dionisio González and Angel Verdejo provided skillful
technical assistance. This work was funded by the Junta de Castilla y León.Peer reviewe
Demographic, clinical, and functional determinants of antithrombotic treatment in patients with nonvalvular atrial fibrillation
Altres ajuts: Alliance Bristol-Myers Squibb/Pfizer.Background: This study assessed the sociodemographic, functional, and clinical determinants of antithrombotic treatment in patients with nonvalvular atrial fibrillation (NVAF) attended in the internal medicine setting. Methods: A multicenter, cross-sectional study was conducted in NVAF patients who attended internal medicine departments for either a routine visit (outpatients) or hospitalization (inpatients). Results: A total of 961 patients were evaluated. Their antithrombotic management included: no treatment (4.7%), vitamin K antagonists (VKAs) (59.6%), direct oral anticoagulants (DOACs) (21.6%), antiplatelets (6.6%), and antiplatelets plus anticoagulants (7.5%). Permanent NVAF and congestive heart failure were associated with preferential use of oral anticoagulation over antiplatelets, while intermediate-to high-mortality risk according to the PROFUND index was associated with a higher likelihood of using antiplatelet therapy instead of oral anticoagulation. Longer disease duration and institutionalization were identified as determinants of VKA use over DOACs. Female gender, higher education, and having suffered a stroke determined a preferential use of DOACs. Conclusions: This real-world study showed that most elderly NVAF patients received oral anticoagulation, mainly VKAs, while DOACs remained underused. Antiplatelets were still offered to a proportion of patients. Longer duration of NVAF and institutionalization were identified as determinants of VKA use over DOACs. A poor prognosis according to the PROFUND index was identified as a factor preventing the use of oral anticoagulation
Pseudomonas aeruginosa antibiotic susceptibility profiles, genomic epidemiology and resistance mechanisms: a nation-wide five-year time lapse analysisResearch in context
Summary: Background: Pseudomonas aeruginosa healthcare-associated infections are one of the top antimicrobial resistance threats world-wide. In order to analyze the current trends, we performed a Spanish nation-wide high-resolution analysis of the susceptibility profiles, the genomic epidemiology and the resistome of P. aeruginosa over a five-year time lapse. Methods: A total of 3.180 nonduplicated P. aeruginosa clinical isolates from two Spanish nation-wide surveys performed in October 2017 and 2022 were analyzed. MICs of 13 antipseudomonals were determined by ISO-EUCAST. Multidrug resistance (MDR)/extensively drug resistance (XDR)/difficult to treat resistance (DTR)/pandrug resistance (PDR) profiles were defined following established criteria. All XDR/DTR isolates were subjected to whole genome sequencing (WGS). Findings: A decrease in resistance to all tested antibiotics, including older and newer antimicrobials, was observed in 2022 vs 2017. Likewise, a major reduction of XDR (15.2% vs 5.9%) and DTR (4.2 vs 2.1%) profiles was evidenced, and even more patent among ICU isolates [XDR (26.0% vs 6.0%) and DTR (8.9% vs 2.6%)] (p < 0.001). The prevalence of Extended-spectrum β-lactamase/carbapenemase production was slightly lower in 2022 (2.1%. vs 3.1%, p = 0.064). However, there was a significant increase in the proportion of carbapenemase production among carbapenem-resistant strains (29.4% vs 18.1%, p = 0.0246). While ST175 was still the most frequent clone among XDR, a slight reduction in its prevalence was noted (35.9% vs 45.5%, p = 0.106) as opposed to ST235 which increased significantly (24.3% vs 12.3%, p = 0.0062). Interpretation: While the generalized decrease in P. aeruginosa resistance, linked to a major reduction in the prevalence of XDR strains, is encouraging, the negative counterpart is the increase in the proportion of XDR strains producing carbapenemases, associated to the significant advance of the concerning world-wide disseminated hypervirulent high-risk clone ST235. Continued high-resolution surveillance, integrating phenotypic and genomic data, is necessary for understanding resistance trends and analyzing the impact of national plans on antimicrobial resistance. Funding: MSD and the Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación and Unión Europea—NextGenerationEU