Examinando por Autor "Leterrier, Marina"
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Ítem Differential transcriptomic analysis by RNA-Seq of GSNO-responsive genes between Arabidopsis roots and leaves(Oxford Academic, 2014-06) Begara-Morales, Juan Carlos; Sánchez-Calvo, Beatriz; Luque-Vázquez, Francisco; Leyva-Pérez, María O; Leterrier, Marina; Corpas, Francisco Javier; Barroso-Albarracín, Juan BautistaS-Nitrosoglutathione (GSNO) is a nitric oxide-derived molecule that can regulate protein function by a post-translational modification designated S-nitrosylation. GSNO has also been detected in different plant organs under physiological and stress conditions, and it can also modulate gene expression. Thirty-day-old Arabidopsis plants were grown under hydroponic conditions, and exogenous 1 mM GSNO was applied to the root systems for 3 h. Differential gene expression analyses were carried out both in roots and in leaves by RNA sequencing (RNA-seq). A total of 3,263 genes were identified as being modulated by GSNO. Most of the genes identified were associated with the mechanism of protection against stress situations, many of these having previously been identified as target genes of GSNO by array-based methods. However, new genes were identified, such as that for methionine sulfoxide reductase (MSR) in leaves or different miscellaneous RNA (miscRNA) genes in Arabidopsis roots. As a result, 1,945 GSNO-responsive genes expressed differently in leaves and roots were identified, and 114 of these corresponded exclusively to one of these organs. In summary, it is demonstrated that RNA-seq extends our knowledge of GSNO as a signaling molecule which differentially modulates gene expression in roots and leaves under non-stress conditions.Ítem High temperature triggers the metabolism of S-nitrosothiols in sunflower mediating a process of nitrosative stress which provokes the inhibition of ferredoxin-NADP reductase by tyrosine nitration(WILEY, 2011-06) Chaki, Mounira; Valderrama, Raquel; Fernández-Ocaña, Ana; Carreras, Alfonso; Gómez-Rodríguez, María Victoria; López-Jaramillo, Jaime; Begara-Morales, Juan Carlos; Sánchez-Calvo, Beatriz; Luque-Vázquez, Francisco; Leterrier, Marina; Corpas, Francisco Javier; Barroso-Albarracín, Juan BautistaHigh temperature (HT) is considered a major abiotic stress that negatively affects both vegetative and reproductive growth. Whereas the metabolism of reactive oxygen species (ROS) is well established under HT, less is known about the metabolism of reactive nitrogen species (RNS). In sunflower (Helianthus annuus L.) seedlings exposed to HT, NO content as well as S-nitrosoglutathione reductase (GSNOR) activity and expression were down-regulated with the simultaneous accumulation of total S-nitrosothiols (SNOs) including S-nitrosoglutathione (GSNO). However, the content of tyrosine nitration (NO2-Tyr) studied by highperformance liquid chromatography with tandem mass spectrometry (LC–MS/MS) and by confocal laser scanning microscope was induced. Nitroproteome analysis under HT showed that this stress induced the protein expression of 13 tyrosine-nitrated proteins. Among the induced proteins, ferredoxin–NADP reductase (FNR) was selected to evaluate the effect of nitration on its activity after heat stress and in vitro conditions using 3-morpholinosydnonimine (SIN-1) (peroxynitrite donor) as the nitrating agent, the FNR activity being inhibited. Taken together, these results suggest that HT augments SNOs, which appear to mediate protein tyrosine nitration, inhibiting FNR, which is involved in the photosynthesis process.Ítem Mechanical wounding induces a nitrosative stress by down-regulation of GSNO reductase and an increase in S-nitrosothiols in sunflower (Helianthus annuus) seedlings(OXFORD UNIVERSITY PRESS, 2011-03) Chaki, Mounira; Valderrama, Raquel; Fernández-Ocaña, Ana; Carreras, Alfonso; Gómez-Rodríguez, María Victoria; Pedrajas, José Rafael; Begara-Morales, Juan Carlos; Sánchez-Calvo, Beatriz; Luque-Vázquez, Francisco; Leterrier, Marina; Corpas, Francisco Javier; Barroso-Albarracín, Juan BautistaNitric oxide (NO) and related molecules such as peroxynitrite, S-nitrosoglutathione (GSNO), and nitrotyrosine, among others, are involved in physiological processes as well in the mechanisms of response to stress conditions. In sunflower seedlings exposed to five different adverse environmental conditions (low temperature, mechanical wounding, high light intensity, continuous light, and continuous darkness), key components of the metabolism of reactive nitrogen species (RNS) and reactive oxygen species (ROS), including the enzyme activities L-argininedependent nitric oxide synthase (NOS), S-nitrosogluthathione reductase (GSNOR), nitrate reductase (NR), catalase, and superoxide dismutase, the content of lipid hydroperoxide, hydrogen peroxide, S-nitrosothiols (SNOs), the cellular level of NO, GSNO, and GSNOR, and protein tyrosine nitration [nitrotyrosine (NO2-Tyr)] were analysed. Among the stress conditions studied, mechanical wounding was the only one that caused a down-regulation of NOS and GSNOR activities, which in turn provoked an accumulation of SNOs. The analyses of the cellular content of NO, GSNO, GSNOR, and NO2-Tyr by confocal laser scanning microscopy confirmed these biochemical data. Therefore, it is proposed that mechanical wounding triggers the accumulation of SNOs, specifically GSNO, due to a downregulation of GSNOR activity, while NO2-Tyr increases. Consequently a process of nitrosative stress is induced in sunflower seedlings and SNOs constitute a new wound signal in plants.Ítem Metabolism of reactive oxygen species and reactive nitrogen species in pepper (Capsicum annuum L.) plants under low temperature stress(WILEY, 2012-02) Airaki, Morad; Leterrier, Marina; Mateos, Rosa María; Valderrama, Raquel; Chaki, Mounira; Barroso-Albarracín, Juan Bautista; del-Río, Luis Alfonso; Palma, José Manuel; Corpas, Francisco JavierLow temperature is an environmental stress that affects crop production and quality and regulates the expression of many genes, and the level of a number of proteins and metabolites. Using leaves from pepper (Capsicum annum L.) plants exposed to low temperature (8°C) for different time periods (1 to 3d), several key components of the metabolism of reactive nitrogen and oxygen species (RNS and ROS, respectively) were analysed. After 24h of exposure at 8°C, pepper plants exhibited visible symptoms characterized by flaccidity of stems and leaves. This was accompanied by significant changes in the metabolism of RNS and ROS with an increase of both protein tyrosine nitration (NO2-Tyr) and lipid peroxidation, indicating that low temperature induces nitrosative and oxidative stress. During the second and third days at low temperature, pepper plants underwent cold acclimation by adjusting their antioxidant metabolism and reverting the observed nitrosative and oxidative stress. In this process, the levels of the soluble non-enzymatic antioxidants ascorbate and glutathione, and the activity of the main NADPH-generating dehydrogenases were significantly induced. This suggests that ascorbate, glutathione and the NADPH-generating dehydrogenases have a role in the process of cold acclimation through their effect on the redox state of the cell.Ítem Protein tyrosine nitration in pea roots during development and senescence(OXFORD UNIV PRESS, 2013-01-28) Begara-Morales, Juan Carlos; Chaki, Mounira; Sánchez-Calvo, Beatriz; Mata-Pérez, Capilla; Leterrier, Marina; Palma, José Manuel; Barroso-Albarracín, Juan Bautista; Corpas, Francisco JavierProtein tyrosine nitration is a post-translational modification mediated by reactive nitrogen species (RNS) that is associated with nitro-oxidative damage. No information about this process is available in relation to higher plants during development and senescence. Using pea plants at different developmental stages (ranging from 8 to 71 days), tyrosine nitration in the main organs (roots, stems, leaves, flowers, and fruits) was analysed using immunological and proteomic approaches. In the roots of 71-day-old senescent plants, nitroproteome analysis enabled the identification a total of 16 nitrotyrosine-immunopositive proteins. Among the proteins identified, NADP-isocitrate dehydrogenase (ICDH), an enzyme involved in the carbon and nitrogen metabolism, redox regulation, and responses to oxidative stress, was selected to evaluate the effect of nitration. NADP-ICDH activity fell by 75% during senescence. Analysis showed that peroxynitrite inhibits recombinant cytosolic NADP-ICDH activity through a process of nitration. Of the 12 tyrosines present in this enzyme, mass spectrometric analysis of nitrated recombinant cytosolic NADP-ICDH enabled this study to identify the Tyr392 as exclusively nitrated by peroxynitrite. The data as a whole reveal that protein tyrosine nitration is a nitric oxide-derived PTM prevalent throughout root development and intensifies during senescence.