9 research outputs found

    Pycnogenol® and Ginkgo biloba extract: effect on peroxynitrite-oxidized sarcoplasmic reticulum Ca2+-ATPase

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    The effect of two natural standardized plant extracts, Pycnogenol® and EGb 761, on sarcoplasmic reticulum Ca2+-ATPase (SERCA) activity and posttranslational modifications induced by peroxynitrite was investigated to assess their possible protective role. EGb 761 was found to have a protective effect on SERCA activity in the concentration range of 5–40 µg/ml. On the other hand, Pycnogenol® caused a decrease of SERCA activity at concentrations of 25 µg/ml. EGb 761 did not prevent protein carbonyl formation upon oxidation with peroxynitrite. On the contrary, Pycnogenol® at the concentrations of 5 and 10 µg/ml significantly decreased the level of protein carbonyls by 44% and 54%, respectively. Neither Pycnogenol® nor EGb 761 exerted a protective effect against thiol group oxidation.The plant extracts studied modulated peroxynitrite-injured SERCA activity by different ways and failed to correlate with posttranslational modifications. Their effect seems to be associated with their ability to change SERCA conformation rather than by their antioxidant capacity

    Abscisic acid induced a negative geotropic response in dark-incubated Chlamydomonas reinhardtii

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    © 2019, The Author(s). The phytohormone abscisic acid (ABA) plays a role in stresses that alter plant water status and may also regulate root gravitropism and hydrotropism. ABA also exists in the aquatic algal progenitors of land plants, but other than its involvement in stress responses, its physiological role in these microorganisms remains elusive. We show that exogenous ABA significantly altered the HCO3− uptake of Chamydomonas reinhardtii in a light-intensity-dependent manner. In high light ABA enhanced HCO3− uptake, while under low light uptake was diminished. In the dark, ABA induced a negative geotropic movement of the algae to an extent dependent on the time of sampling during the light/dark cycle. The algae also showed a differential, light-dependent directional taxis response to a fixed ABA source, moving horizontally towards the source in the light and away in the dark. We conclude that light and ABA signal competitively in order for algae to position themselves in the water column to minimise photo-oxidative stress and optimise photosynthetic efficiency. We suggest that the development of this response mechanism in motile algae may have been an important step in the evolution of terrestrial plants and that its retention therein strongly implicates ABA in the regulation of their relevant tropisms

    PESFOR-W: Improving the design and environmental effectiveness of woodlands for water Payments for Ecosystem Services

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    ABSTRACT: The EU Water Framework Directive aims to ensure restoration of Europe?s water bodies to ?good ecological status? by 2027. Many Member States will struggle to meet this target, with around half of EU river catchments currently reporting below standard water quality. Diffuse pollution from agriculture represents a major pressure, affecting over 90% of river basins. Accumulating evidence shows that recent improvements to agricultural practices are benefiting water quality but in many cases will be insufficient to achieve WFD objectives. There is growing support for land use change to help bridge the gap, with a particular focus on targeted tree planting to intercept and reduce the delivery of diffuse pollutants to water. This form of integrated catchment management offers multiple benefits to society but a significant cost to landowners and managers. New economic instruments, in combination with spatial targeting, need to be developed to ensure cost effective solutions - including tree planting for water benefits - are realised. Payments for Ecosystem Services (PES) are flexible, incentive-based mechanisms that could play an important role in promoting land use change to deliver water quality targets. The PESFOR-W COST Action will consolidate learning from existing woodlands for water PES schemes in Europe and help standardize approaches to evaluating the environmental effectiveness and cost-effectiveness of woodland measures. It will also create a European network through which PES schemes can be facilitated, extended and improved, for example by incorporating other ecosystem services linking with aims of the wider forestscarbon policy nexus

    Changes in cytokinin contents and metabolism in spinach in response to zinc excess in soil

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    Changes in endogenous cytokinin (CK) contents and metabolism in spinach (Spinacia oleracea L.) responding to excessive amounts of zinc in soil were studied. Application of three zinc rates in soil (250, 500, 750 mg.kg-1) resulted in a progressive (1.7- to 3.3-times) increase of endogenous CKs in spinach leaves. This increase was predominantly due to accumulation of inactive and storage CK forms (N- and O-glucosides) and was accompanied with an enhanced activity of cytokinin oxidase/dehydrogenase (CKX), the key CK degradative enzyme, especially on the highest zinc rate (750 mg.kg-1 soil). On this rate, maximum endogenous CK concentrations in both control and stressed plants were found at the first and the last samplings, i.e. in the course of very young leaf development and just before or during flowering. The CKX activity of stressed plants exceeded that of controls during the whole development and reached the maxima at the last sampling of treated plants

    Tomato (Solanum lycopersicum L.) SlIPT3 and SlIPT4 isopentenyltransferases mediate salt stress response in tomato

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    Background: Cytokinins (CKs) are involved in response to various environmental cues, including salinity. It has been previously reported that enhancing CK contents improved salt stress tolerance in tomato. However, the underlying mechanisms of CK metabolism and signaling under salt stress conditions remain to be deciphered. Results: Two tomato isopentenyltransferases, SlIPT3 and SlIPT4, were characterized in tomato and Arabidopsis. Both proteins displayed isopentenyltransferase (IPT) activity in vitro, while their encoding genes exhibited different spatio-temporal expression patterns during tomato plant development. SlIPT3 and SlIPT4 were affected by the endogenous CK status, tightly connected with CKs feedback regulation, as revealed by hormonal treatements. In response to salt stress, SlIPT3 and SlIPT4 were strongly repressed in tomato roots, and differently affected in young and old leaves. SlIPT3 overexpression in tomato resulted in high accumulation of different CK metabolites, following modifications of CK biosynthesis-, signaling- and degradation-gene expression. In addition, 35S::SlIPT3 tomato plants displayed improved tolerance to salinity consecutive to photosynthetic pigments and K+/Na+ ratio retention. Involvement of SlIPT3 and SlIPT4 in salt stress response was also observed in Arabidopsis ipt3 knock-out complemented plants, through maintenance of CK homeostasis. Conclusions: SlIPT3 and SlIPT4 are functional IPTs encoded by differently expressed genes, distinctively taking part in the salinity response. The substantial participation of SlIPT3 in CK metabolism during salt stress has been determined in 35S::SlIPT3 tomato transformants, where enhancement of CKs accumulation significantly improved plant tolerance to salinity, underlining the importance of this phytohormone in stress response. © Žižková et al.; licensee BioMed Central

    Association study for 26 candidate loci in idiopathic pulmonary fibrosis patients from four European populations

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    Idiopathic pulmonary fibrosis (IPF) affects lung parenchyma with progressing fibrosis. In this study, we aimed to replicate MUC5B rs35705950 variants and determine new plausible candidate variants for IPF among four different European populations. We genotyped 26 IPF candidate loci in 165 IPF patients from four European countries, such as Czech Republic (n = 41), Germany (n = 33), Greece (n = 40), France (n = 51), and performed association study comparing observed variant distribution with that obtained in a genetically similar Czech healthy control population (n = 96) described in our earlier data report. A highly significant association for a promoter variant (rs35705950) of mucin encoding MUC5B gene was observed in all IPF populations, individually and combined [odds ratio (95% confidence interval); p-value as 5.23 (8.94-3.06); 1.80 × 10-11]. Another non-coding variant, rs7934606 in MUC2 was significant among German patients [2.85 (5.05-1.60); 4.03 × 10-4] and combined European IPF cases [2.18 (3.16-1.50); 3.73 × 10-5]. The network analysis for these variants indicated gene-gene and gene-phenotype interactions in IPF and lung biology. With replication of MUC5B rs35705950 previously reported in U.S. populations of European descent and indicating other plausible polymorphic variants relevant for IPF, we provide additional reference information for future extended functional and population studies aimed, ideally with inclusion of clinical parameters, at identification of IPF genetic markers. © 2016 Kishore, Žižková, Kocourková, Petrkova, Bouros, Nunes, Loštáková, Müller-Quernheim, Zissel, Kolek, Bouros,Valeyre and Petrek

    Association study for 26 candidate loci in idiopathic pulmonary fibrosis patients from four European populations

    No full text
    Idiopathic pulmonary fibrosis (IPF) affects lung parenchyma with progressing fibrosis. In this study, we aimed to replicate MUC5B rs35705950 variants and determine new plausible candidate variants for IPF among four different European populations. We genotyped 26 IPF candidate loci in 165 IPF patients from four European countries, such as Czech Republic (n = 41), Germany (n = 33), Greece (n = 40), France (n = 51), and performed association study comparing observed variant distribution with that obtained in a genetically similar Czech healthy control population (n = 96) described in our earlier data report. A highly significant association for a promoter variant (rs35705950) of mucin encoding MUC5B gene was observed in all IPF populations, individually and combined [odds ratio (95% confidence interval); p-value as 5.23 (8.94-3.06); 1.80 × 10-11]. Another non-coding variant, rs7934606 in MUC2 was significant among German patients [2.85 (5.05-1.60); 4.03 × 10-4] and combined European IPF cases [2.18 (3.16-1.50); 3.73 × 10-5]. The network analysis for these variants indicated gene-gene and gene-phenotype interactions in IPF and lung biology. With replication of MUC5B rs35705950 previously reported in U.S. populations of European descent and indicating other plausible polymorphic variants relevant for IPF, we provide additional reference information for future extended functional and population studies aimed, ideally with inclusion of clinical parameters, at identification of IPF genetic markers. © 2016 Kishore, Žižková, Kocourková, Petrkova, Bouros, Nunes, Loštáková, Müller-Quernheim, Zissel, Kolek, Bouros,Valeyre and Petrek
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