ABSTRACT
Low 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 3 d), several key components of the metabolism of reactive nitrogen and oxygen species (RNS and ROS, respectively) were analysed. After 24 h 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.
Low temperature is an environmental stress that affects plants growth and consequently crop production and quality. Pepper plants are a worldwide consumable vegetables affected for this stress. In this work it is studied how low temperature influences the metabolism of reactive oxygen and nitrogen species as well as the redox state being the soluble antioxidants (ascorbate and glutathione) and the NADPH‐generating dehydrogenases key components in the process of cold acclimation.
Nitrosative stress in plants Valderrama, Raquel; Corpas, Francisco J.; Carreras, Alfonso ...
FEBS letters,
February 06, 2007, Letnik:
581, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Nitrosative stress has become a usual term in the physiology of nitric oxide in mammalian systems. However, in plants there is much less information on this type of stress. Using olive leaves as ...experimental model, the effect of salinity on the potential induction of nitrosative stress was studied. The enzymatic
l-arginine-dependent production of nitric oxide (NOS activity) was measured by ozone chemiluminiscence. The specific activity of NOS in olive leaves was 0.280
nmol NO
mg
−1 protein
min
−1, and was dependent on
l-arginine, NADPH and calcium. Salt stress (200
mM NaCl) caused an increase of the
l-arginine-dependent production of nitric oxide (NO), total
S-nitrosothiols (RSNO) and number of proteins that underwent tyrosine nitration. Confocal laser scanning microscopy analysis using either specific fluorescent probes for NO and RSNO or antibodies to
S-nitrosoglutathione and 3-nitrotyrosine, showed also a general increase of these reactive nitrogen species (RNS) mainly in the vascular tissue. Taken together, these findings show that in olive leaves salinity induces nitrosative stress, and vascular tissues could play an important role in the redistribution of NO-derived molecules during nitrosative stress.
Recent studies in animal systems have shown that NO can interact with fatty acids to generate nitro-fatty acids (NO2-FAs). They are the product of the reaction between reactive nitrogen species and ...unsaturated fatty acids, and are considered novel mediators of cell signaling based mainly on a proven anti-inflammatory response. Although these signaling mediators have been described widely in animal systems, NO2-FAs have scarcely been studied in plants. Preliminary data have revealed the endogenous presence of free and protein-adducted NO2-FAs in extra-virgin olive oil (EVOO), which appear to be contributing to the cardiovascular benefits associated with the Mediterranean diet. Importantly, new findings have displayed the endogenous occurrence of nitro-linolenic acid (NO2-Ln) in the model plant Arabidopsis thaliana and the modulation of NO2-Ln levels throughout this plant's development. Furthermore, a transcriptomic analysis by RNA-seq technology established a clear signaling role for this molecule, demonstrating that NO2-Ln was involved in plant-defense response against different abiotic-stress conditions, mainly by inducing the chaperone network and supporting a conserved mechanism of action in both animal and plant defense processes. Thus, NO2-Ln levels significantly rose under several abiotic-stress conditions, highlighting the strong signaling role of these molecules in the plant-protection mechanism. Finally, the potential of NO2-Ln as a NO donor has recently been described both in vitro and in vivo. Jointly, this ability gives NO2-Ln the potential to act as a signaling molecule by the direct release of NO, due to its capacity to induce different changes mediated by NO or NO-related molecules such as nitration and S-nitrosylation, or by the electrophilic capacity of these molecules through a nitroalkylation mechanism. Here, we describe the current state of the art regarding the advances performed in the field of NO2-FAs in plants and their implication in plant physiology.
Nitro-fatty acid signaling in plants. Pathway 1 indicates that NO2-Ln is able to induce a defense mechanism through the induction of the chaperone network and the increase in the expression of some antioxidant enzymes such as APX. This latter may be involved in the alleviation of the oxidative stress generated by the overproduction of ROS such as H2O2. Furthermore, NO2-Ln is a NO donor being therefore implicated in the wide range of actions in which this molecule is involved (pathway 2). The electrophilic ability of this nitro-fatty acid could contribute to the signaling actions involving NO2-FAs (pathway 3) and, under nitro-oxidative stress conditions, the oxidation of Michael adducts may occur with subsequent NO2-FA release (pathway 4) and the observed antioxidant properties of these molecules. NO: nitric oxide; HSP: heat shock protein; APX: ascorbate peroxidase. Display omitted
•Nitro-Linolenic acid is an endogenous molecule whose levels are modulated throughout Arabidopsis development.•Nitro-Linolenic acid induces the molecular chaperone network in Arabidopsis.•Nitro-fatty acids are able to act as a signaling mediators in the plant-defense mechanism in abiotic and oxidative stress situations, setting up a defense response against cell damage.•Nitro-fatty acids have been demonstrated to be in vitro and in vivo NO donors.•The nitro-fatty acid detection in other plant species highlight a ubiquitous distribution of nitro-fatty acids in plant kingdom and the potential signaling actions of these molecules in plant systems.
The development of seedlings involves many morphological, physiological and biochemical processes, which are controlled by many factors. Some reactive oxygen and nitrogen species (ROS and RNS, ...respectively) are implicated as signal molecules in physiological and phytopathological processes. Pepper (Capsicum annuum) is a very important crop and the goal of this work was to provide a framework of the behaviour of the key elements in the metabolism of ROS and RNS in the main organs of pepper during its development.
The main seedling organs (roots, hypocotyls and green cotyledons) of pepper seedlings were analysed 7, 10 and 14 d after germination. Activity and gene expression of the main enzymatic antioxidants (catalase, ascorbate-glutathione cycle enzymes), NADP-generating dehydrogenases and S-nitrosoglutathione reductase were determined. Cellular distribution of nitric oxide ((·)NO), superoxide radical (O2 (·-)) and peroxynitrite (ONOO(-)) was investigated using confocal laser scanning microscopy.
The metabolism of ROS and RNS during pepper seedling development was highly regulated and showed significant plasticity, which was co-ordinated among the main seedling organs, resulting in correct development. Catalase showed higher activity in the aerial parts of the seedling (hypocotyls and green cotyledons) whereas roots of 7-d-old seedlings contained higher activity of the enzymatic components of the ascorbate glutathione cycle, NADP-isocitrate dehydrogenase and NADP-malic enzyme.
There is differential regulation of the metabolism of ROS, nitric oxide and NADP dehydrogenases in the different plant organs during seedling development in pepper in the absence of stress. The metabolism of ROS and RNS seems to contribute significantly to plant development since their components are involved directly or indirectly in many metabolic pathways. Thus, specific molecules such as H2O2 and NO have implications for signalling, and their temporal and spatial regulation contributes to the success of seedling establishment.
During the last decade, it was established that the class III alcohol dehydrogenase (ADH3) enzyme, also known as glutathione-dependent formaldehyde dehydrogenase (FALDH; EC 1.2.1.1), catalyzes the ...NADH-dependent reduction of S-nitrosoglutathione (GSNO) and therefore was also designated as GSNO reductase. This finding has opened new aspects in the metabolism of nitric oxide (NO) and NO-derived molecules where GSNO is a key component. In this article, current knowledge of the involvement and potential function of this enzyme during plant development and under biotic/abiotic stress is briefly reviewed.
In recent years, the study of nitric oxide (NO) in plant systems has attracted the attention of many researchers. A growing number of investigations have shown the significance of NO as a signal ...molecule or as a molecule involved in the response against (a)biotic processes. NO can be responsible of the post-translational modifications (NO-PTM) of target proteins by mechanisms such as the nitration of tyrosine residues. The study of protein tyrosine nitration during development and under biotic and adverse environmental conditions has increased in the last decade; nevertheless, there is also an endogenous nitration which seems to have regulatory functions. Moreover, the advance in proteome techniques has enabled the identification of new nitrated proteins, showing the high variability among plant organs, development stage and species. Finally, it may be important to discern between a widespread protein nitration because of greater RNS content, and the specific nitration of key targets which could affect cell-signaling processes. In view of the above point, we present a mini-review that offers an update about the endogenous protein tyrosine nitration, during plant development and under several abiotic stress conditions.
Nitric oxide (·NO) has been shown to participate in plant response against pathogen infection; however, less is known of the participation of other NO-derived molecules designated as reactive ...nitrogen species (RNS). Using two sunflower (Helianthus annuus L.) cultivars with different sensitivity to infection by the pathogen Plasmopara halstedii, we studied key components involved in RNS and ROS metabolism. We analyzed the superoxide radical production, hydrogen peroxide content, l-arginine-dependent nitric oxide synthase (NOS) and S-nitrosoglutathione reductase (GSNOR) activities. Furthermore, we examined the location and contents of ·NO, S-nitrosothiols (RSNOs), S-nitrosoglutathione (GSNO) and protein 3-nitrotyrosine (NO2-Tyr) by confocal laser scanning microscopy (CLSM) and biochemical analyses. In the susceptible cultivar, the pathogen induces an increase in proteins that undergo tyrosine nitration accompanied by an augmentation in RSNOs. This rise of RSNOs seems to be independent of the enzymatic generation of ·NO because the l-arginine-dependent NOS activity is reduced after infection. These results suggest that pathogens induce nitrosative stress in susceptible cultivars. In contrast, in the resistant cultivar, no increase of RSNOs or tyrosine nitration of proteins was observed, implying an absence of nitrosative stress. Therefore, it is proposed that the increase of tyrosine nitration of proteins can be considered a general biological marker of nitrosative stress in plants under biotic conditions.
Nitric oxide (NO) is an important signalling molecule in different animal and plant physiological processes. Little is known about its biological function in plants and on the enzymatic source or ...site of NO production during plant development. The endogenous NO production from L-arginine (NO synthase activity) was analyzed in leaves, stems and roots during plant development, using pea seedlings as a model. NOS activity was analyzed using a novel chemiluminescence-based assay which is more sensitive and specific than previous methods used in plant tissues. In parallel, NO accumulation was analyzed by confocal laser scanning microscopy using as fluorescent probes either DAF-2 DA or DAF-FM DA. A strong increase in NOS activity was detected in stems after 11 days growth, coinciding with the maximum stem elongation. The arginine-dependent NOS activity was constitutive and sensitive to aminoguanidine, a well-known irreversible inhibitor of animal NOS, and this NOS activity was differentially modulated depending on the plant organ and seedling developmental stage. In all tissues studied, NO was localized mainly in the vascular tissue (xylem) and epidermal cells and in root hairs. These loci of NO generation and accumulation suggest novel functions for NO in these cell types.
Protein tyrosine nitration is a post-translational modification (PTM) mediated by nitric oxide-derived molecules. Peroxisomes are oxidative organelles in which the presence of nitric oxide (NO) has ...been reported.
We studied peroxisomal nitroproteome of pea leaves by high-performance liquid chromatography with tandem mass spectrometry (LC–MS/MS) and proteomic approaches.
Proteomic analysis of peroxisomes from pea leaves detected a total of four nitro-tyrosine immunopositive proteins by using an antibody against nitrotyrosine. One of these proteins was found to be the NADH-dependent hydroxypyruvate reductase (HPR). The in vitro nitration of peroxisomal samples caused a 65% inhibition of HPR activity. Analysis of recombinant peroxisomal NADH-dependent HPR1 activity from Arabidopsis in the presence of H2O2, NO, GSH and peroxynitrite showed that the ONOO− molecule caused the highest inhibition of activity (51% at 5mM SIN-1), with 5mM H2O2 having no inhibitory effect. Mass spectrometric analysis of the nitrated recombinant HPR1 enabled us to determine that, among the eleven tyrosine present in this enzyme, only Tyr-97, Tyr-108 and Tyr-198 were exclusively nitrated to 3-nitrotyrosine by peroxynitrite. Site-directed mutagenesis confirmed Tyr198 as the primary site of nitration responsible for the inhibition on the enzymatic activity by peroxynitrite.
These findings suggest that peroxisomal HPR is a target of peroxynitrite which provokes a loss of function.
This is the first report demonstrating the peroxisomal NADH-dependent HPR activity involved in the photorespiration pathway is regulated by tyrosine nitration, indicating that peroxisomal NO metabolism may contribute to the regulation of physiological processes under no-stress conditions.
Display omitted
•Protein tyrosine nitration is a PTM mediated by NO-derived molecules.•Peroxisomal NADH-dependent HPR activity is a target of tyrosine nitration.•Tyr198 of HPR is the primary site of nitration responsible for the inhibition.
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