Nitric oxide (NO) is considered as a signalling molecule involved in a variety of important physiological and pathological processes in plant and animal systems. The major pathway of NO reactions in vivo represents S-nitrosation of thiols to form S-nitrosothiols. S-nitrosoglutathione reductase (GSNOR) is the key enzyme in the degradation pathway of S-nitrosoglutathione (GSNO), a low-molecular weight adduct of NO and glutathione. GSNOR indirectly regulates the level of protein S-nitrosothiol in the cells. This study was focused on the dynamic regulation of the activity of plant GSNORs through reversible S-nitrosation and/or oxidative modifications of target cysteine residues. Pre-incubation with NO/NO- donors or hydrogen peroxide resulted in a decreased reductase and dehydrogenase activity of all studied plant GSNORs. Incubation with thiol reducing agent completely reversed inhibitory effects of nitrosative modifications and partially also oxidative inhibition. In biotin-labelled samples, S-nitrosation of plant GSNORs was confirmed after immunodetection and using mass spectrometry S-nitrosation of conserved Cys271 was identified in tomato GSNOR. Negative regulation of constitutive GSNOR activity in vivo by nitrosative or oxidative modifications might present an important mechanism to control GSNO levels, a critical mediator of the downstream signalling effects of NO, as well as for formaldehyde detoxification in dehydrogenase reaction mode.

• MeSH
• aldehydoxidoreduktasy antagonisté a inhibitory   chemie   metabolismus   MeSH
• cystein chemie   metabolismus   MeSH
• donory oxidu dusnatého farmakologie   MeSH
• nitrosace MeSH
• oxid dusnatý metabolismus   MeSH
• oxidace-redukce MeSH
• peroxid vodíku farmakologie   MeSH
• posttranslační úpravy proteinů MeSH
• rekombinantní proteiny chemie   genetika   metabolismus   MeSH
• rostlinné proteiny antagonisté a inhibitory   chemie   metabolismus   MeSH
• S-nitrosoglutathion metabolismus   MeSH
• S-nitrosothioly metabolismus   MeSH
• signální transdukce MeSH
• Solanum lycopersicum genetika   růst a vývoj   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

S-nitrosoglutathione reductase (GSNOR) exerts crucial roles in the homeostasis of nitric oxide (NO) and reactive nitrogen species (RNS) in plant cells through indirect control of S-nitrosation, an important protein post-translational modification in signaling pathways of NO. Using cultivated and wild tomato species, we studied GSNOR function in interactions of key enzymes of reactive oxygen species (ROS) metabolism with RNS mediated by protein S-nitrosation during tomato root growth and responses to salinity and cadmium. Application of a GSNOR inhibitor N6022 increased both NO and S-nitrosothiol levels and stimulated root growth in both genotypes. Moreover, N6022 treatment, as well as S-nitrosoglutathione (GSNO) application, caused intensive S-nitrosation of important enzymes of ROS metabolism, NADPH oxidase (NADPHox) and ascorbate peroxidase (APX). Under abiotic stress, activities of APX and NADPHox were modulated by S-nitrosation. Increased production of H2O2 and subsequent oxidative stress were observed in wild Solanumhabrochaites, together with increased GSNOR activity and reduced S-nitrosothiols. An opposite effect occurred in cultivated S. lycopersicum, where reduced GSNOR activity and intensive S-nitrosation resulted in reduced ROS levels by abiotic stress. These data suggest stress-triggered disruption of ROS homeostasis, mediated by modulation of RNS and S-nitrosation of NADPHox and APX, underlies tomato root growth inhibition by salinity and cadmium stress.

• MeSH
• aldehydoxidoreduktasy metabolismus   MeSH
• askorbátperoxidasa metabolismus   MeSH
• benzamidy chemie   metabolismus   farmakologie   MeSH
• chlorid sodný farmakologie   MeSH
• fyziologický stres MeSH
• kadmium toxicita   MeSH
• kořeny rostlin účinky léků   růst a vývoj   metabolismus   MeSH
• NADPH-oxidasy metabolismus   MeSH
• nitrosace MeSH
• oxid dusnatý metabolismus   MeSH
• oxidační stres účinky léků   MeSH
• peroxid vodíku metabolismus   MeSH
• pyrroly chemie   metabolismus   farmakologie   MeSH
• reaktivní formy dusíku chemie   metabolismus   MeSH
• reaktivní formy kyslíku chemie   metabolismus   MeSH
• regulace genové exprese u rostlin účinky léků   MeSH
• rostlinné proteiny metabolismus   MeSH
• S-nitrosoglutathion farmakologie   MeSH
• S-nitrosothioly metabolismus   MeSH
• Solanum lycopersicum účinky léků   růst a vývoj   metabolismus   MeSH
• Solanum růst a vývoj   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

S-nitrosation, the attachment of a nitroso group to cysteine thiols, has been recognized as an important posttranslational modification of proteins by nitric oxide and related reactive nitrogen species. Mechanisms and significance of S-nitrosation in the regulation of the structure and activity of proteins have been extensively studied in animal and plant systems. In plants, protein S-nitrosation is involved in signaling pathways of plant hormones and regulators during plant growth and development and in responses to abiotic and biotic stress stimuli. S-nitrosoglutathione reductase (GSNOR) has been identified as a key enzyme controlling the intracellular level of S-nitrosothiols. GSNOR irreversibly degrades S-nitrosoglutathione (GSNO), the major low molecular weight S-nitrosothiol involved in the formation of protein S-nitrosothiols through transnitrosylation. GSNOR level and activity in plant cells are modulated during plant development and in response to external stimuli such as pathogen infection. In this chapter, we give a detailed description of the immunochemical detection of the GSNOR protein in plant samples.

• MeSH
• aldehydoxidoreduktasy metabolismus   MeSH
• posttranslační úpravy proteinů * MeSH
• rostlinné proteiny metabolismus   MeSH
• rostliny metabolismus   MeSH
• S-nitrosoglutathion metabolismus   MeSH
• S-nitrosothioly metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH

S-nitrosylation of protein cysteine thiol groups has recently emerged as a widespread and important reversible post-translational protein modification, involved in redox signalling pathways of nitric oxide and reactive nitrogen species. S-nitrosoglutathione reductase (GSNOR), member of class III alcohol dehydrogenase family (EC 1.1.1.1), is considered the key enzyme in the catabolism of major low molecular S-nitrosothiol, S-nitrosoglutathione, and hence to control the level of protein S-nitrosylation. Changes of GSNOR activity after exposure to different abiotic stress conditions, including low and high temperature, continuous dark and de-etiolation, and mechanical injury, were investigated in important agricultural plants. Significantly higher GSNOR activity was found under normal conditions in leaves of Cucumis spp. genotype sensitive to biotrophic pathogen Golovinomyces cichoracearum. GSNOR activity was generally increased in all studied plants by all types of stress conditions. Strong down-regulation of GSNOR was observed in hypocotyls of etiolated pea plants, which did not recover to values of green plants even 168 h after the transfer of etiolated plants to normal light regime. These results point to important role of GSNOR during normal plant development and in plant responses to several types of abiotic stress conditions.

• MeSH
• aldehydoxidoreduktasy metabolismus   MeSH
• Ascomycota patogenita   MeSH
• Cucumis melo enzymologie   genetika   mikrobiologie   MeSH
• Cucumis sativus enzymologie   genetika   mikrobiologie   MeSH
• fyziologický stres * MeSH
• hrách setý enzymologie   mikrobiologie   MeSH
• hypokotyl enzymologie   MeSH
• mechanický stres MeSH
• nízká teplota MeSH
• reakce na tepelný šok MeSH
• světlo MeSH
• vývoj rostlin MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH