RESUMEN
Plant survival to a potential plethora of diverse environmental insults is underpinned by coordinated communication amongst organs to help shape effective responses to these environmental challenges at the whole plant level. This interorgan communication is supported by a complex signal network that regulates growth, development and environmental responses. Nitric oxide (NO) has emerged as a key signalling molecule in plants. However, its potential role in interorgan communication has only recently started to come into view. Direct and indirect evidence has emerged supporting that NO and related species (S-nitrosoglutathione, nitro-linolenic acid) are mobile interorgan signals transmitting responses to stresses such as hypoxia and heat. Beyond their role as mobile signals, NO and related species are involved in mediating xylem development, thus contributing to efficient root-shoot communication. Moreover, NO and related species are regulators in intraorgan systemic defence responses aiming an effective, coordinated defence against pathogens. Beyond its in planta signalling role, NO and related species may act as ex planta signals coordinating external leaf-to-leaf, root-to-leaf but also plant-to-plant communication. Here, we discuss these exciting developments and emphasise how their manipulation may provide novel strategies for crop improvement.
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Nitric oxide (NO) is a gasotransmitter required in a broad range of mechanisms controlling plant development and stress conditions. However, little is known about the specific role of this signaling molecule during lipid storage in the seeds. Here, we show that NO is accumulated in developing embryos and regulates the fatty acid profile through the stabilization of the basic/leucine zipper transcription factor bZIP67. NO and nitro-linolenic acid target and accumulate bZIP67 to induce the downstream expression of FAD3 desaturase, which is misregulated in a non-nitrosylable version of the protein. Moreover, the post-translational modification of bZIP67 is reversible by the trans-denitrosylation activity of peroxiredoxin IIE and defines a feedback mechanism for bZIP67 redox regulation. These findings provide a molecular framework to control the seed fatty acid profile caused by NO, and evidence of the in vivo functionality of nitro-fatty acids during plant developmental signaling.
Asunto(s)
Proteínas de Arabidopsis , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico , Ácidos Grasos , Peroxirredoxinas , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Ácidos Grasos/metabolismo , Regulación de la Expresión Génica de las Plantas , Metabolismo de los Lípidos , Óxido Nítrico/metabolismo , Peroxirredoxinas/metabolismo , Procesamiento Proteico-Postraduccional , Semillas/metabolismoRESUMEN
The non-enzymatic interaction of polyunsaturated fatty acids with nitric oxide (NO) and derived species results in the formation of nitrated fatty acids (NO2-FAs). These signaling molecules can release NO, reversibly esterify with complex lipids, and modulate protein function through the post-translational modification called nitroalkylation. To date, NO2-FAs act as signaling molecules during plant development in plant systems and are involved in defense responses against abiotic stress conditions. In this work, the previously unknown storage biomolecules of NO2-FAs in Arabidopsis thaliana were identified. In addition, the distribution of NO2-FAs in storage biomolecules during plant development was determined, with phytosterol esters (SE) and TAGs being reservoir biomolecules in seeds, which were replaced by phospholipids and proteins in the vegetative, generative, and senescence stages. The detected esterified NO2-FAs were nitro-linolenic acid (NO2-Ln), nitro-oleic acid (NO2-OA), and nitro-linoleic acid (NO2-LA). The last two were detected for the first time in Arabidopsis. The levels of the three NO2-FAs that were esterified in both lipid and protein storage biomolecules showed a decreasing pattern throughout Arabidopsis development. Esterification of NO2-FAs in phospholipids and proteins highlights their involvement in both biomembrane dynamics and signaling processes, respectively, during Arabidopsis plant development.
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Heat stress is one of the abiotic stresses that leads to oxidative stress. To protect themselves, yeast cells activate the antioxidant response, in which cytosolic peroxiredoxin Tsa1 plays an important role in hydrogen peroxide removal. Concomitantly, the activation of the heat shock response (HSR) is also triggered. Nitro-fatty acids are signaling molecules generated by the interaction of reactive nitrogen species with unsaturated fatty acids. These molecules have been detected in animals and plants. They exert their signaling function mainly through a post-translational modification called nitroalkylation. In addition, these molecules are closely related to the induction of the HSR. In this work, the endogenous presence of nitro-oleic acid (NO2-OA) in Saccharomyces cerevisiae is identified for the first time by LC-MS/MS. Both hydrogen peroxide levels and Tsa1 activity increased after heat stress with no change in protein content. The nitroalkylation of recombinant Tsa1 with NO2-OA was also observed. It is important to point out that cysteine 47 (peroxidatic) and cysteine 171 (resolving) are the main residues responsible for protein activity. Moreover, the in vivo nitroalkylation of Tsa1 peroxidatic cysteine disappeared during heat stress as the hydrogen peroxide generated in this situation caused the rupture of the NO2-OA binding to the protein and, thus, restored Tsa1 activity. Finally, the amino acid targets susceptible to nitroalkylation and the modulatory effect of this PTM on the enzymatic activity of Tsa1 are also shown in vitro and in vivo. This mechanism of response was faster than that involving the induction of genes and the synthesis of new proteins and could be considered as a key element in the fine-tuning regulation of defence mechanisms against oxidative stress in yeast.
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Nitric oxide (NO) is a multifunctional gaseous signal that modulates the growth, development and stress tolerance of higher plants. NO donors have been used to boost plant endogenous NO levels and to activate NO-related responses, but this strategy is often hindered by the relative instability of donors. Alternatively, nanoscience offers a new, promising way to enhance NO delivery to plants, as NO-releasing nanomaterials (e.g. S-nitrosothiol-containing chitosan nanoparticles) have many beneficial physicochemical and biochemical properties compared to non-encapsulated NO donors. Nano NO donors are effective in increasing tissue NO levels and enhancing NO effects both in animal and human systems. The authors believe, and would like to emphasize, that new trends and technologies are essential for advancing plant NO research and nanotechnology may represent a breakthrough in traditional agriculture and environmental science. Herein, we aim to draw the attention of the scientific community to the potential of NO-releasing nanomaterials in both basic and applied plant research as alternatives to conventional NO donors, providing a brief overview of the current knowledge and identifying future research directions. We also express our opinion about the challenges for the application of nano NO donors, such as the environmental footprint and stakeholder's acceptance of these materials.
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Quitosano , Óxido Nítrico , Agricultura , Animales , Biotecnología , Nanotecnología , PlantasRESUMEN
Nitro-fatty acids are generated from the interaction of unsaturated fatty acids and nitric oxide (NO)-derived molecules. The endogenous occurrence and modulation throughout plant development of nitro-linolenic acid (NO2-Ln) and nitro-oleic acid (NO2-OA) suggest a key role for these molecules in initial development stages. In addition, NO2-Ln content increases significantly in stress situations and induces the expression of genes mainly related to abiotic stress, such as genes encoding members of the heat shock response family and antioxidant enzymes. The promoter regions of NO2-Ln-induced genes are also involved mainly in stress responses. These findings confirm that NO2-Ln is involved in plant defense processes against abiotic stress conditions via induction of the chaperone network and antioxidant systems. NO2-Ln signaling capacity lies mainly in its electrophilic nature and allows it to mediate a reversible post-translational modification called nitroalkylation, which is capable of modulating protein function. NO2-Ln is a NO donor that may be involved in NO signaling events and is able to generate S-nitrosoglutathione, the major reservoir of NO in cells and a key player in NO-mediated abiotic stress responses. This review describes the current state of the art regarding the essential role of nitro-fatty acids as signaling mediators in development and abiotic stress processes.
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Ácidos Grasos , Nitratos , Óxido Nítrico , Plantas , Estrés FisiológicoRESUMEN
Nitric oxide plays an important role in the pathogenesis of Pseudoidium neolycopersici, the causative agent of tomato powdery mildew. S-nitrosoglutathione reductase, the key enzyme of S-nitrosothiol homeostasis, was investigated during plant development and following infection in three genotypes of Solanum spp. differing in their resistance to P. neolycopersici. Levels and localization of reactive nitrogen species (RNS) including NO, S-nitrosoglutathione (GSNO) and peroxynitrite were studied together with protein nitration and the activity of nitrate reductase (NR). GSNOR expression profiles and enzyme activities were modulated during plant development and important differences among Solanum spp. genotypes were observed, accompanied by modulation of NO, GSNO, peroxynitrite and nitrated proteins levels. GSNOR was down-regulated in infected plants, with exception of resistant S. habrochaites early after inoculation. Modulations of GSNOR activities in response to pathogen infection were found also on the systemic level in leaves above and below the inoculation site. Infection strongly increased NR activity and gene expression in resistant S. habrochaites in contrast to susceptible S. lycopersicum. Obtained data confirm the key role of GSNOR and modulations of RNS during plant development under normal conditions and point to their involvement in molecular mechanisms of tomato responses to biotrophic pathogens on local and systemic levels.
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Aldehído Oxidorreductasas/metabolismo , Enfermedades de las Plantas , Especies de Nitrógeno Reactivo/metabolismo , Solanum lycopersicum/enzimología , Solanum lycopersicum/microbiología , Ascomicetos/patogenicidad , Genotipo , Enfermedades de las Plantas/microbiologíaRESUMEN
Nitro-fatty acids (NO2-FAs) are novel molecules resulting from the interaction of unsaturated fatty acids and nitric oxide (NO) or NO-related molecules. In plants, it has recently been described that NO2-FAs trigger an antioxidant and a defence response against stressful situations. Among the properties of NO2-FAs highlight the ability to release NO therefore modulating specific protein targets through post-translational modifications (NO-PTMs). Thus, based on the capacity of NO2-FAs to act as physiological NO donors and using high-accuracy mass-spectrometric approaches, herein, we show that endogenous nitro-linolenic acid (NO2-Ln) can modulate S-nitrosoglutathione (GSNO) biosynthesis in Arabidopsis. The incubation of NO2-Ln with GSH was analyzed by LC-MS/MS and the in vitro synthesis of GSNO was noted. The in vivo confirmation of this behavior was carried out by incubating Arabidopsis plants with 15N-labeled NO2-Ln throughout the roots, and 15N-labeled GSNO (GS15NO) was detected in the leaves. With the aim to go in depth in the relation of NO2-FA and GSNO in plants, Arabidopsis alkenal reductase mutants (aer mutants) which modulate NO2-FAs levels were used. Our results constitute the first evidence of the modulation of a key NO biological reservoir in plants (GSNO) by these novel NO2-FAs, increasing knowledge about S-nitrosothiols and GSNO-signaling pathways in plants.
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Environmental stresses negatively affect plant growth, development and crop productivity [...].
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Nitric oxide (NO) is perfectly suited for the role of a redox signalling molecule. A key route for NO bioactivity occurs via protein S-nitrosation, and involves the addition of a NO moiety to a protein cysteine (Cys) thiol (-SH) to form an S-nitrosothiol (SNO). This process is thought to underpin a myriad of cellular processes in plants that are linked to development, environmental responses and immune function. Here we collate emerging evidence showing that NO bioactivity regulates a growing number of diverse post-translational modifications including SUMOylation, phosphorylation, persulfidation and acetylation. We provide examples of how NO orchestrates these processes to mediate plant adaptation to a variety of cellular cues.
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Óxido Nítrico , S-Nitrosotioles , Óxido Nítrico/metabolismo , Nitrosación , Oxidación-Reducción , Plantas/metabolismo , Procesamiento Proteico-PostraduccionalRESUMEN
Nitric oxide (NO) emerged as a key signal molecule in plants. During the last two decades impressive progress has been made in plant NO research. This small, redox-active molecule is now known to play an important role in plant immunity, stress responses, environmental interactions, plant growth and development. To more accurately and robustly establish the full spectrum of NO bioactivity in plants, it will be essential to apply methodological best practice. In addition, there are some instances of conflicting nomenclature within the field, which would benefit from standardization. In this context, we attempt to provide some helpful guidance for best practice associated with NO research and also suggestions for the cognate terminology.
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Óxido Nítrico , Plantas , Desarrollo de la PlantaRESUMEN
Nitric oxide (NO) is a crucial signaling molecule that conveys its bioactivity mainly through protein S-nitrosylation. This is a reversible post-translational modification (PTM) that may affect protein function. S-nitrosoglutathione (GSNO) is a cellular NO reservoir and NO donor in protein S-nitrosylation. The enzyme S-nitrosoglutathione reductase (GSNOR) degrades GSNO, thereby regulating indirectly signaling cascades associated with this PTM. Here, the two GSNORs of the legume Lotus japonicus, LjGSNOR1 and LjGSNOR2, have been functionally characterized. The LjGSNOR1 gene is very active in leaves and roots, whereas LjGSNOR2 is highly expressed in nodules. The enzyme activities are regulated in vitro by redox-based PTMs. Reducing conditions and hydrogen sulfide-mediated cysteine persulfidation induced both activities, whereas cysteine oxidation or glutathionylation inhibited them. Ljgsnor1 knockout mutants contained higher levels of S-nitrosothiols. Affinity chromatography and subsequent shotgun proteomics allowed us to identify 19 proteins that are differentially S-nitrosylated in the mutant and the wild-type. These include proteins involved in biotic stress, protein degradation, antioxidant protection and photosynthesis. We propose that, in the mutant plants, deregulated protein S-nitrosylation contributes to developmental alterations, such as growth inhibition, impaired nodulation and delayed flowering and fruiting. Our results highlight the importance of GSNOR function in legume biology.
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Aldehído Oxidorreductasas/genética , Genes de Plantas , Lotus/genética , Aldehído Oxidorreductasas/metabolismo , Cisteína/metabolismo , Lotus/metabolismo , Óxido Nítrico/metabolismo , Donantes de Óxido Nítrico/metabolismo , Oxidación-Reducción , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Procesamiento Proteico-Postraduccional , Proteína S/genética , Proteína S/metabolismo , Proteómica , S-Nitrosoglutatión , S-Nitrosotioles/metabolismo , Espectrometría de Masas en TándemRESUMEN
Low temperature (LT) negatively affects plant growth and development via the alteration of the metabolism of reactive oxygen and nitrogen species (ROS and RNS). Among RNS, tyrosine nitration, the addition of an NO2 group to a tyrosine residue, can modulate reduced nicotinamide-dinucleotide phosphate (NADPH)-generating systems and, therefore, can alter the levels of NADPH, a key cofactor in cellular redox homeostasis. NADPH also acts as an indispensable electron donor within a wide range of enzymatic reactions, biosynthetic pathways, and detoxification processes, which could affect plant viability. To extend our knowledge about the regulation of this key cofactor by this nitric oxide (NO)-related post-translational modification, we analyzed the effect of tyrosine nitration on another NADPH-generating enzyme, the NADP-malic enzyme (NADP-ME), under LT stress. In Arabidopsis thaliana seedlings exposed to short-term LT (4 °C for 48 h), a 50% growth reduction accompanied by an increase in the content of superoxide, nitric oxide, and peroxynitrite, in addition to diminished cytosolic NADP-ME activity, were found. In vitro assays confirmed that peroxynitrite inhibits cytosolic NADP-ME2 activity due to tyrosine nitration. The mass spectrometric analysis of nitrated NADP-ME2 enabled us to determine that Tyr-73 was exclusively nitrated to 3-nitrotyrosine by peroxynitrite. The in silico analysis of the Arabidopsis NADP-ME2 protein sequence suggests that Tyr73 nitration could disrupt the interactions between the specific amino acids responsible for protein structure stability. In conclusion, the present data show that short-term LT stress affects the metabolism of ROS and RNS, which appears to negatively modulate the activity of cytosolic NADP-ME through the tyrosine nitration process.
RESUMEN
Nitric oxide (NO) is an active redox molecule involved in the control of a wide range of functions integral to plant biology. For instance, NO is implicated in seed germination, floral development, senescence, stomatal closure, and plant responses to stress. NO usually mediates signaling events via interactions with different biomolecules, for example the modulation of protein functioning through post-translational modifications (NO-PTMs). S-nitrosation is a reversible redox NO-PTM that consists of the addition of NO to a specific thiol group of a cysteine residue, leading to formation of S-nitrosothiols (SNOs). SNOs are more stable than NO and therefore they can extend and spread the in vivo NO signaling. The development of robust and reliable detection methods has allowed the identification of hundreds of S-nitrosated proteins involved in a wide range of physiological and stress-related processes in plants. For example, SNOs have a physiological function in plant development, hormone metabolism, nutrient uptake, and photosynthesis, among many other processes. The role of S-nitrosation as a regulator of plant responses to salinity and drought stress through the modulation of specific protein targets has also been well established. However, there are many S-nitrosated proteins that have been identified under different abiotic stresses for which the specific roles have not yet been identified. In this review, we examine current knowledge of the specific role of SNOs in the signaling events that lead to plant responses to abiotic stress, with a particular focus on examples where their functions have been well characterized at the molecular level.
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Fenómenos Fisiológicos de las Plantas , Proteínas de Plantas/metabolismo , S-Nitrosotioles/metabolismo , Transducción de Señal , Plantas/metabolismo , Estrés FisiológicoRESUMEN
Among biotic constraints affecting olive trees cultivation worldwide, the soil-borne fungus Verticillium dahliae is considered one of the most serious threats. Olive cultivars display differential susceptibility to the disease, but our knowledge on the pathogen's responses when infecting varieties differing in susceptibility is scarce. A comparative transcriptomic analysis (RNA-seq) was conducted in olive cultivars Picual (susceptible) and Frantoio (tolerant). RNA samples originated from roots during the first two weeks after inoculation with V. dahliae defoliating (D) pathotype. Verticillium dahliae mRNA amount was overwhelmingly higher in roots of the susceptible cultivar, indicating that proliferation of pathogen biomass is favored in 'Picual'. A significant larger number of V. dahliae unigenes (11 fold) were only induced in this cultivar. Seven clusters of differentially expressed genes (DEG) were identified according to time-course expression patterns. Unigenes potentially coding for niche-adaptation, pathogenicity, virulence and microsclerotia development were induced in 'Picual', while in 'Frantoio' expression remained negligible or null. Verticillium dahliae D pathotype transcriptome responses are qualitatively and quantitatively different, and depend on cultivar susceptibility level. The much larger V. dahliae biomass found in 'Picual' roots is a consequence of both host and pathogen DEG explaining, to a large extent, the higher aggressiveness exerted over this cultivar.
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Adaptación Fisiológica/genética , Olea/crecimiento & desarrollo , Transcriptoma/genética , Verticillium/genética , Susceptibilidad a Enfermedades , Olea/microbiología , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Raíces de Plantas/genética , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/microbiología , Análisis de Secuencia de ARN , Microbiología del Suelo , Verticillium/patogenicidadRESUMEN
Nitrate fatty acids (NO2-FAs) are considered reactive lipid species derived from the non-enzymatic oxidation of polyunsaturated fatty acids by nitric oxide (NO) and related species. Nitrate fatty acids are powerful biological electrophiles which can react with biological nucleophiles such as glutathione and certain proteinâ»amino acid residues. The adduction of NO2-FAs to protein targets generates a reversible post-translational modification called nitroalkylation. In different animal and human systems, NO2-FAs, such as nitro-oleic acid (NO2-OA) and conjugated nitro-linoleic acid (NO2-cLA), have cytoprotective and anti-inflammatory influences in a broad spectrum of pathologies by modulating various intracellular pathways. However, little knowledge on these molecules in the plant kingdom exists. The presence of NO2-OA and NO2-cLA in olives and extra-virgin olive oil and nitro-linolenic acid (NO2-Ln) in Arabidopsis thaliana has recently been detected. Specifically, NO2-Ln acts as a signaling molecule during seed and plant progression and beneath abiotic stress events. It can also release NO and modulate the expression of genes associated with antioxidant responses. Nevertheless, the repercussions of nitroalkylation on plant proteins are still poorly known. In this review, we demonstrate the existence of endogenous nitroalkylation and its effect on the in vitro activity of the antioxidant protein ascorbate peroxidase.
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Plant peroxisomes have the capacity to generate different reactive oxygen and nitrogen species (ROS and RNS), such as H2 O2 , superoxide radical (O2 · - ), nitric oxide and peroxynitrite (ONOO- ). These organelles have an active nitro-oxidative metabolism which can be exacerbated by adverse stress conditions. Hydrogen sulfide (H2 S) is a new signaling gasotransmitter which can mediate the posttranslational modification (PTM) persulfidation. We used Arabidopsis thaliana transgenic seedlings expressing cyan fluorescent protein (CFP) fused to a canonical peroxisome targeting signal 1 (PTS1) to visualize peroxisomes in living cells, as well as a specific fluorescent probe which showed that peroxisomes contain H2 S. H2 S was also detected in chloroplasts under glyphosate-induced oxidative stress conditions. Peroxisomal enzyme activities, including catalase, photorespiratory H2 O2 -generating glycolate oxidase (GOX) and hydroxypyruvate reductase (HPR), were assayed in vitro with a H2 S donor. In line with the persulfidation of this enzyme, catalase activity declined significantly in the presence of the H2 S donor. To corroborate the inhibitory effect of H2 S on catalase activity, we also assayed pure catalase from bovine liver and pepper fruit-enriched samples, in which catalase activity was inhibited. Taken together, these data provide evidence of the presence of H2 S in plant peroxisomes which appears to regulate catalase activity and, consequently, the peroxisomal H2 O2 metabolism.
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Arabidopsis/metabolismo , Sulfuro de Hidrógeno/metabolismo , Peroxisomas/metabolismo , Oxidorreductasas de Alcohol/metabolismo , Catalasa/metabolismo , Hidroxipiruvato Reductasa/metabolismo , Óxido Nítrico/metabolismo , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Nitric oxide (NO) has emerged as an essential biological messenger in plant biology that usually transmits its bioactivity by post-translational modifications such as S-nitrosylation, the reversible addition of an NO group to a protein cysteine residue leading to S-nitrosothiols (SNOs). In recent years, SNOs have risen as key signalling molecules mainly involved in plant response to stress. Chief among SNOs is S-nitrosoglutathione (GSNO), generated by S-nitrosylation of the key antioxidant glutathione (GSH). GSNO is considered the major NO reservoir and a phloem mobile signal that confers to NO the capacity to be a long-distance signalling molecule. GSNO is able to regulate protein function and gene expression, resulting in a key role for GSNO in fundamental processes in plants, such as development and response to a wide range of environmental stresses. In addition, GSNO is also able to regulate the total SNO pool and, consequently, it could be considered the storage of NO in cells that may control NO signalling under basal and stress-related responses. Thus, GSNO function could be crucial during plant response to environmental stresses. Besides the importance of GSNO in plant biology, its mode of action has not been widely discussed in the literature. In this review, we will first discuss the GSNO turnover in cells and secondly the role of GSNO as a mediator of physiological and stress-related processes in plants, highlighting those aspects for which there is still some controversy.
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Óxido Nítrico/metabolismo , Fenómenos Fisiológicos de las Plantas , S-Nitrosoglutatión/metabolismo , Transducción de Señal , Estrés FisiológicoRESUMEN
Nitro-fatty acids (NO2-FAs) are formed from the reaction between nitrogen dioxide (NO2) and mono and polyunsaturated fatty acids. Knowledge concerning NO2-FAs has significantly increased within a few years ago and the beneficial actions of these species uncovered in animal systems have led to consider them as molecules with therapeutic potential. Based on their nature and structure, NO2-FAs have the ability to release nitric oxide (NO) in aqueous environments and the capacity to mediate post-translational modifications (PTM) by nitroalkylation. Recently, based on the potential of these NO-derived molecules in the animal field, the endogenous occurrence of nitrated-derivatives of linolenic acid (NO2-Ln) was assessed in plant species. Moreover and through RNA-seq technology, it was shown that NO2-Ln can induce a large set of heat-shock proteins (HSPs) and different antioxidant systems suggesting this molecule may launch antioxidant and defence responses in plants. Furthermore, the capacity of this nitro-fatty acid to release NO has also been demonstrated. In view of this background, here we offer an overview on the biological properties described for NO2-FAs in plants and the potential of these molecules to be considered new key intermediaries of NO metabolism in the plant field.