共查询到20条相似文献,搜索用时 31 毫秒
1.
Gases such as ethylene, hydrogen peroxide (H 2O 2), nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H 2S) have been recognized as vital signaling molecules in plants and animals. Of these gasotransmitters, NO and H 2S have recently gained momentum mainly because of their involvement in numerous cellular processes. It is therefore important to study their various attributes including their biosynthetic and signaling pathways. The present review provides an insight into various routes for the biosynthesis of NO and H 2S as well as their signaling role in plant cells under different conditions, more particularly under heavy metal stress. Their beneficial roles in the plant's protection against abiotic and biotic stresses as well as their adverse effects have been addressed. This review describes how H 2S and NO, being very small-sized molecules, can quickly pass through the cell membranes and trigger a multitude of responses to various factors, notably to various stress conditions such as drought, heat, osmotic, heavy metal and multiple biotic stresses. The versatile interactions between H 2S and NO involved in the different molecular pathways have been discussed. In addition to the signaling role of H 2S and NO, their direct role in posttranslational modifications is also considered. The information provided here will be helpful to better understand the multifaceted roles of H 2S and NO in plants, particularly under stress conditions. 相似文献
2.
Hydrogen sulfide (H 2S) has emerged as an important gaseous signaling molecule that is produced endogenously by enzymes in the sulfur metabolic network. H 2S exerts its effects on multiple physiological processes important under both normal and pathological conditions. These functions include neuromodulation, regulation of blood pressure and cardiac function, inflammation, cellular energetics and apoptosis. Despite the recognition of its biological importance and its beneficial effects, the mechanism of H 2S action and the regulation of its tissue levels remain unclear in part owing to its chemical and physical properties that render handling and analysis challenging. Furthermore, the multitude of potential H 2S effects has made it difficult to dissect its signaling mechanism and to identify specific targets. In this review, we focus on H 2S metabolism and provide an overview of the recent literature that sheds some light on its mechanism of action in cellular redox signaling in health and disease. This article is part of a Special Issue entitled: Thiol-Based Redox Processes. 相似文献
3.
近年来,内源性H_2S作为第3种被发现的新型气体信号分子,其生理学作用逐渐受到研究者的重视.在哺乳动物体内,H_2S与血红素蛋白的结合有两种方式,一种是H_2S直接键合血红素中心Fe形成Fe-H_2S复合物;另一种则是H_2S修饰血红素卟啉环,形成硫代血红素结构.我们选用肌红蛋白(myoglobin,Mb)作为研究对象,通过点突变技术改变了血红素活性中心结构,结合紫外-可见光谱学以及X-射线晶体学,研究了H_2S与不同突变型Mb反应后的光谱和结构变化.结果显示:血红素中心近、远端腔微环境的变化,如腔体极性、氢键数目、氢键位置等因素直接影响蛋白质与H_2S的结合,以及硫代血红素(sulfheme)的形成.这些结果为研究血红素蛋白参与内源性H_2S代谢机理提供了重要的实验数据. 相似文献
4.
Cystathionine gamma-lyase (CSE)-derived hydrogen sulfide (H2S) plays an essential role in preserving cardiac functions. Angiotensin-converting enzyme 2 (ACE2) acts as the negative regulator of the renin-angiotensin system, exerting anti-oxidative stress and anti-inflammatory properties within the body. The interplays of CSE/H2S signaling and ACE2 in cardiac aging are unclear. In this study, the regulatory roles of H2S on ACE2 expression in mouse heart tissue and rat cardiomyocytes under different stress conditions were investigated. It was found that ACE2 protein level was lower in heart tissues from old mice (56-week-old) than young mice (8-week-old), and the knockout of CSE (CSE KO) induced moderate oxidative stress and further inhibited ACE2 protein level in mouse hearts at both young and old age. Incubation of rat cardiac cells (H9C2) with a low dose of H2O2 (50 µM) suppressed ACE2 protein level and induced cellular senescence, which was completely reversed by co-incubation with 30 µM NaHS (a H2S donor). Prolonged nutrient excess is an increased risk of heart disorders by causing metabolic dysfunction and cardiac remodeling. We further found high-fat diet feeding stimulated ACE2 expression and induced severe oxidative stress in CSE KO heart in comparison with wild-type heart. Lipid overload in H9C2 cells to mimic a status of nutrient excess also enhanced the expression of ACE2 protein and induced severe oxidative stress and cell senescence, which were significantly attenuated by the supplementation of exogenous H2S. Furthermore, the manipulation of ACE2 expression partially abolished the protective role of H2S against cellular senescence. These results demonstrate the dynamic roles of H2S in the maintenance of ACE2 levels under different levels of oxidative stress, pointing to the potential implications in targeting the CSE/H2S system for the interruption of aging and diabetes-related heart disorders. 相似文献
5.
Hydrogen sulfide (H2S) has emerged as a novel gaseous signal molecule with multifarious effects on seed germination, plant growth, development, and physiological processes. Due to its dominant role in plant stress tolerance and cross-adaptation, it is getting more attention nowadays, although it has been largely referred as toxic and environmental hazardous gas. In this review work, we are highlighting the importance of H2S as an essential gaseous molecule to help in signaling, metabolism, and stress tolerance in plants. Firstly, production of H2S from different natural and artificial sources were discussed with its transformation from sulfur (S) to sulfate (SO42−) and then to sulfite (SO32−). The importance of different kinds of transporters that helps to take SO42− from the soil solution was presented. Mainly, these transporters are SULTRs (H+/SO42− cotransporters) and multigene family encodes them. Furthermore, these SULTRs have LAST (Low affinity transport proteins), HAST (High affinity transport proteins), vacuole transporters, and plastid transporters. Since it is well known that there is strong relationship between SO42− and synthesis of hydrogen sulfide or dihydrogen sulfide or sulfane in plant cells. Thus, cysteine (Cys) metabolism through which H2S could be generated in plant cell with the role of different enzymes has been presented. Furthermore, H2S in interaction with other molecules could help to mitigate biotic and abiotic stress. Based on this review work, it can be concluded that H2S has potential to induce cross-adaptation to biotic and abiotic stress; thus, it is recommended that it should be considered in future studies to answer the questions like what are the receptors of H2S in plant cell, where in plants the physiological concentration of H2S is high in response to multiple stress and how it induces cross-adaptation by interaction with other signal molecules. 相似文献
6.
Sulfane sulfur species comprise a variety of biologically relevant hydrogen sulfide (H 2S)-derived species, including per- and poly-sulfidated low molecular weight compounds and proteins. A growing body of evidence suggests that H 2S, currently recognized as a key signaling molecule in human physiology and pathophysiology, plays an important role in cancer biology by modulating cell bioenergetics and contributing to metabolic reprogramming. This is accomplished through functional modulation of target proteins via H 2S binding to heme iron centers or H 2S-mediated reversible per- or poly-sulfidation of specific cysteine residues. Since sulfane sulfur species are increasingly viewed not only as a major source of H 2S but also as key mediators of some of the biological effects commonly attributed to H 2S, the multifaceted role of these species in cancer biology is reviewed here with reference to H 2S, focusing on their metabolism, signaling function, impact on cell bioenergetics and anti-tumoral properties. 相似文献
7.
Hydrogen sulfide (H 2S), as a potential gaseous messenger molecule, has been suggested to play important roles in a wide range of physiological processes in plants. The aim of present study was to investigate which set of proteins is involved in H 2S-regulated metabolism or signaling pathways. Spinacia oleracea seedlings were treated with 100 µM NaHS, a donor of H 2S. Changes in protein expression profiles were analyzed by 2-D gel electrophoresis coupled with MALDI-TOF MS. Over 1000 protein spots were reproducibly resolved, of which the abundance of 92 spots was changed by at least 2-fold (sixty-five were up-regulated, whereas 27 were down-regulated). These proteins were functionally divided into 9 groups, including energy production and photosynthesis, cell rescue, development and cell defense, substance metabolism, protein synthesis and folding, cellular signal transduction. Further, we found that these proteins were mainly localized in cell wall, plasma membrane, chloroplast, mitochondria, nucleus, peroxisome and cytosol. Our results demonstrate that H 2S is involved in various cellular and physiological activities and has a distinct influence on photosynthesis, cell defense and cellular signal transduction in S. oleracea leaves. These findings provide new insights into proteomic responses in plants under physiological levels of H 2S. 相似文献
8.
In plants, investigation on heavy metal toxicity and its mitigation by nutrient elements have gained much attention. However, mechanism(s) associated with nutrients-mediated mitigation of metal toxicity remain elusive. In this study, we have investigated the role and interrelation of glutathione (GSH) and hydrogen sulfide (H 2S) in the regulation of hexavalent chromium [Cr(VI)] toxicity in tomato ( Solanum lycopersicum), pea ( Pisum sativum) and brinjal ( Solanum melongena) seedlings, supplemented with additional sulfur (S). The results show that Cr(VI) significantly reduced growth, total chlorophyll and photosynthetic quantum yield of tomato, pea and brinjal seedlings which was accompanied by enhanced intracellular accumulation of Cr(VI) in roots. Moreover, Cr(VI) enhanced the generation of reactive oxygen species in the studied vegetables, while antioxidant defense system exhibited differential responses. However, additional supply of S alleviated Cr(VI) toxicity. Interestingly, addition of l-buthionine sulfoximine (BSO, a glutathione biosynthesis inhibitor) further increased Cr(VI) toxicity even in the presence of additional S but GSH addition reverses the effect of BSO. Under similar condition, endogenous H 2S, l-cysteine desulfhydrase (DES) activity and cysteine content did not significantly differ when compared to controls. Hydroxylamine (HA, an inhibitor of DES) also increased Cr(VI) toxicity even in the presence of additional S but sodium hydrosulfide (NaHS, an H 2S donor) reverses the effect of HA. Moreover, Cr(VI) toxicity amelioration by NaHS was reversed by the addition of hypotaurine (HT, an H 2S scavenger). Taken together, the results show that GSH which might be derived from supplied S is involved in the mitigation of Cr(VI) toxicity in which H 2S signaling preceded GSH biosynthesis. 相似文献
9.
Hydrogen sulfide (H 2S) is a versatile molecule with different functions in living organisms: it can work as a metabolite of sulfur and energetic metabolism or as a signaling molecule in higher Eukaryotes. H 2S is also highly toxic since it is able to inhibit heme cooper oxygen reductases, preventing oxidative phosphorylation. Due to the fact that it can both inhibit and feed the respiratory chain, the immediate role of H 2S on energy metabolism crucially relies on its bioavailability, meaning that studying the central players involved in the H 2S homeostasis is key for understanding sulfide metabolism.Two different enzymes with sulfide oxidation activity (sulfide dehydrogenases) are known: flavocytochrome c sulfide dehydrogenase (FCSD), a sulfide:cytochrome c oxidoreductase; and sulfide:quinone oxidoreductase (SQR).In this work we performed a thorough bioinformatic study of SQRs and FCSDs and integrated all published data. We systematized several properties of these proteins: (i) nature of flavin binding, (ii) capping loops and (iii) presence of key amino acid residues. We also propose an update to the SQR classification system and discuss the role of these proteins in sulfur metabolism. 相似文献
10.
The oscillation of intracellular calcium (Ca 2+) concentration is a primary event in numerous biological processes in plants, including stress response. Hydrogen sulfide (H 2S), an emerging gasotransmitter, was found to have positive effects in plants responding to chromium (Cr 6+) stress through interacting with Ca 2+ signaling. While Ca 2+ resemblances H 2S in mediating biotic and abiotic stresses, crosstalk between the two pathways remains unclear. In this study, Ca 2+ signaling interacted with H 2S to produce a complex physiological response, which enhanced the Cr 6+ tolerance in foxtail millet ( Setaria italica). Results indicate that Cr 6+ stress activated endogenous H 2S synthesis as well as Ca 2+ signaling. Moreover, toxic symptoms caused by Cr 6+ stress were strongly moderated by 50 μM H 2S and 20 mM Ca 2+. Conversely, treatments with H 2S synthesis inhibitor and Ca 2+ chelators prior to Cr 6+-exposure aggravated these toxic symptoms. Interestingly, Ca 2+ upregulated expression of two important factors in metal metabolism, MT3A and PCS, which participated in the biosynthesis of heavy metal chelators, in a H 2S-dependent manner to cope with Cr 6+ stress. These findings also suggest that the H 2S dependent pathway is a component of the Ca 2+ activating antioxidant system and H 2S partially contributes Ca 2+-activating antioxidant system. 相似文献
11.
Gaseous molecules, such as hydrogen sulfide(H_2S)and nitric oxide(NO), are crucial players in cellular and(patho)physiological processes in biological systems. The biological functions of these gaseous molecules, which were first discovered and identified as gasotransmitters in animals, have received unprecedented attention from plant scientists in recent decades. Researchers have arrived at the consensus that H_2S is synthesized endogenously and serves as a signaling molecule throughout the plant life cycle.However, the mechanisms of H_2S action in redox biology is still largely unexplored. This review highlights what we currently know about the characteristics and biosynthesis of H_2S in plants. Additionally,we summarize the role of H_2S in plant resistance to abiotic stress. Moreover, we propose and discuss possible redox-dependent mechanisms by which H_2S regulates plant physiology. 相似文献
12.
As a signaling molecule, hydrogen sulfide (H2S) plays an indispensable role in the modulation of ripening and senescence in fruits and vegetables. To explore the role of H2S in regulating metabolism of postharvest tomato, ripening-related physiological parameters, activities of antioxidant enzymes and gene expression were analyzed in H2S-fumigated tomato fruits. These results show that H2S significantly delayed the color transition and softening of tomato fruit, and maintained higher level of flavonoids and lower level of anthocyanin during storage. Besides, H2S could maintain higher level of nutritional-related metabolites, such as reducing sugar, ascorbic acid during postharvest storage. Moreover, H2S decreased the rate of O2− production, inhibited the production of H2O2 and malondialdehyde (MDA), enhanced the activities of antioxidant enzymes including ascorbate peroxidase (APX), superoxide dismutase (SOD), catalase (CAT) and guaiacol peroxidase (POD) in tomato fruits, while reduced the activities of phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO) and lipoxygenase (LOX). Besides, the expression of the antioxidant-encoding genes SlCAT2, SlPOD12 was generally upregulated with H2S fumigation. Principal component analysis (PCA) suggests that H2S induced significant discrepancy mainly to the differences in firmness, anthocyanin, flavonoid and the activity of guaiacol peroxidase (POD), and the correlation analysis further shows that H2S affected pigment metabolism and nutritional quality. In conclusion, H2S could maintain better appearance and nutritional quality, and prolong the storage period of postharvest tomato fruits through activating the antioxidative system. 相似文献
13.
AbstractThe present paper is an overview of studying of DNA-porphyrin interactions using viscometry in combination with the spectroscopic methods. It was shown, that when porphyrins interact with DNA as an outside binder, the interaction mode and intensity does not depend on metal center, peripheral substituent’s and their positions on pyridylic ring. In case of planar porphyrins, the binding type is mainly determined by type of peripheral substituent’s and their position on the pyridylic ring. Currently, viscometry is widely used to study the interaction of porphyrins with DNA as an adjunct to other methods. Due to high accuracy and maximum sensitivity to changes in the size and shape of macromolecules, it is recommended to use viscometry as the cogent method for studying the interaction of small molecules with DNA, especially if intercalation is expected using other methods if necessary to confirm the results obtained. Abbreviations DNA deoxyribonucleic acid H 2TAllPyP4 meso-tetra-(4N-allylpyridyl) porphyrin H 2TAllPyP3 meso-tetra-(3N-allylpyridyl) porphyrin H 2THOEtPyP4 meso-tetra-(4N-hydroxyethylpyridyl) porphyrin H 2THOEtPyP3 meso-tetra-(3N-hydroxyethylpyridyl) porphyrin UV/VIS spectrophotometry ultraviolet-visible spectrophotometry CD spectroscopy circular dichroism spectroscopy Communicated by Ramaswamy H. Sarma 相似文献
14.
Hydrogen sulfide (H 2S) was once principally considered the perpetrator of plant growth cessation and cell death. However, this has become an antiquated view, with cumulative evidence showing that the H 2S serves as a biological signaling molecule notably involved in abiotic stress response and adaptation, such as defense by phytohormone activation, stomatal movement, gene reprogramming, and plant growth modulation. Reactive oxygen species (ROS)-dependent oxidative stress is involved in these responses. Remarkably, an ever-growing body of evidence indicates that H 2S can directly interact with ROS processing systems in a redox-dependent manner, while it has been gradually recognized that H 2S-based posttranslational modifications of key protein cysteine residues determine stress responses. Furthermore, the reciprocal interplay between H 2S and nitric oxide (NO) in regulating oxidative stress has significant importance. The interaction of H 2S with NO and ROS during acclimation to abiotic stress may vary from synergism to antagonism. However, the molecular pathways and factors involved remain to be identified. This review not only aims to provide updated information on H 2S action in regulating ROS-dependent redox homeostasis and signaling, but also discusses the mechanisms of H 2S-dependent regulation in the context of oxidative stress elicited by environmental cues. 相似文献
15.
Toxic heavy metals constitute a worldwide environmental pollution problem. Bioremediation technologies represent efficient alternatives to the classic cleaning-up of contaminated soil and ground water. Most toxic heavy metals such as chromium are less soluble and toxic when reduced than when oxidized. Sulfate-reducing bacteria (SRB) are able to reduce heavy metals by a chemical reduction via the production of H 2S and by a direct enzymatic process involving hydrogenases and c 3 cytochromes. We have previously reported the effects of chromate [Cr(VI)] on SRB bioenergetic metabolism and the molecular mechanism of the metal reduction by polyhemic cytochromes. In the current work, we pinpoint the bacteria–metal interactions using Desulfovibrio vulgaris strain Hildenborough as a model. The bacteria were grown in the presence of high Cr(VI) concentration, where they accumulated precipitates of a reduced form of chromium, trivalent chromium [Cr(III)], on their cell surfaces. Moreover, the inner and outer membranes exhibited precipitates that shared the spectroscopic signature of trivalent chromium. This subcellular localization is consistent with enzymatic metal reduction by cytochromes and hydrogenases. Regarding environmental significance, our findings point out the Cr(VI) immobilization mechanisms of SRB; suggesting that SRB are highly important in metal biogeochemistry. 相似文献
16.
Heavy metal toxicity is one of the major abiotic stresses leading to hazardous health effects in animals and plants. Because
of their high reactivity they can directly influence growth, senescence and energy synthesis processes. In this review a new
indirect mechanism of heavy metal action is proposed. This mechanism is connected with the generation of reactive oxygen species
(especially H 2O 2) and jasmonate and ethylene signaling pathways and shows that toxicity symptoms observed in plants may result from direct
heavy metal influence as well as the activity of some signaling molecules induced by the stress action. 相似文献
17.
Environmental and occupational exposure to heavy metals such as cadmium, mercury and lead results in severe health hazards including prenatal and developmental defects. The deleterious effects of heavy metal ions have hitherto been attributed to their interactions with specific, particularly susceptible native proteins. Here, we report an as yet undescribed mode of heavy metal toxicity. Cd 2+, Hg 2+ and Pb 2+ proved to inhibit very efficiently the spontaneous refolding of chemically denatured proteins by forming high-affinity multidentate complexes with thiol and other functional groups (IC 50 in the nanomolar range). With similar efficacy, the heavy metal ions inhibited the chaperone-assisted refolding of chemically denatured and heat-denatured proteins. Thus, the toxic effects of heavy metal ions may result as well from their interaction with the more readily accessible functional groups of proteins in nascent and other non-native form. The toxic scope of heavy metals seems to be substantially larger than assumed so far. 相似文献
18.
Hydrogen sulfide (H 2S) is an endogenously produced gaseous molecule with important roles in cellular signaling. In mammals, exogenous H 2S improves survival of ischemia/reperfusion. We have previously shown that exposure to H 2S increases the lifespan and thermotolerance in Caenorhabditis elegans, and improves protein homeostasis in low oxygen. The mitochondrial SQRD-1 (sulfide quinone oxidoreductase) protein is a highly conserved enzyme involved in H 2S metabolism. SQRD-1 is generally considered important to detoxify H 2S. Here, we show that SQRD-1 is also required to maintain protein translation in H 2S. In sqrd-1 mutant animals, exposure to H 2S leads to phosphorylation of eIF2α and inhibition of protein synthesis. In contrast, global protein translation is not altered in wild-type animals exposed to lethally high H 2S or in hif-1(ia04) mutants that die when exposed to low H 2S. We demonstrate that both gcn-2 and pek-1 kinases are involved in the H 2S-induced phosphorylation of eIF2α. Both ER and mitochondrial stress responses are activated in sqrd-1 mutant animals exposed to H 2S, but not in wild-type animals. We speculate that SQRD-1 activity in H 2S may coordinate proteostasis responses in multiple cellular compartments. 相似文献
19.
Until now, physiological mechanisms and downstream targets responsible for the cadmium (Cd) tolerance mediated by endogenous hydrogen sulfide (H 2S) have been elusive. To address this gap, a combination of pharmacological, histochemical, biochemical and molecular approaches was applied. The perturbation of reduced (homo)glutathione homeostasis and increased H 2S production as well as the activation of two H 2S-synthetic enzymes activities, including L-cysteine desulfhydrase (LCD) and D-cysteine desulfhydrase (DCD), in alfalfa seedling roots were early responses to the exposure of Cd. The application of H 2S donor sodium hydrosulfide (NaHS), not only mimicked intracellular H 2S production triggered by Cd, but also alleviated Cd toxicity in a H 2S-dependent fashion. By contrast, the inhibition of H 2S production caused by the application of its synthetic inhibitor blocked NaHS-induced Cd tolerance, and destroyed reduced (homo)glutathione and reactive oxygen species (ROS) homeostases. Above mentioned inhibitory responses were further rescued by exogenously applied glutathione (GSH). Meanwhile, NaHS responses were sensitive to a (homo)glutathione synthetic inhibitor, but reversed by the cotreatment with GSH. The possible involvement of cyclic AMP (cAMP) signaling in NaHS responses was also suggested. In summary, LCD/DCD-mediated H 2S might be an important signaling molecule in the enhancement of Cd toxicity in alfalfa seedlings mainly by governing reduced (homo)glutathione and ROS homeostases. 相似文献
20.
In the recent times, plants are facing certain types of environmental stresses, which give rise to formation of reactive oxygen species (ROS) such as hydroxyl radicals, hydrogen peroxides, superoxide anions and so on. These are required by the plants at low concentrations for signal transduction and at high concentrations, they repress plant root growth. Apart from the ROS activities, hydrogen sulfide (H 2S) and nitric oxide (NO) have major contributions in regulating growth and developmental processes in plants, as they also play key roles as signaling molecules and act as chief plant immune defense mechanisms against various biotic as well as abiotic stresses. H 2S and NO are the two pivotal gaseous messengers involved in growth, germination and improved tolerance in plants under stressed and non-stress conditions. H 2S and NO mediate cell signaling in plants as a response to several abiotic stresses like temperature, heavy metal exposure, water and salinity. They alter gene expression levels to induce the synthesis of antioxidant enzymes, osmolytes and also trigger their interactions with each other. However, research has been limited to only cross adaptations and signal transductions. Understanding the change and mechanism of H 2S and NO mediated cell signaling will broaden our knowledge on the various biochemical changes that occur in plant cells related to different stresses. A clear understanding of these molecules in various environmental stresses would help to confer biotechnological applications to protect plants against abiotic stresses and to improve crop productivity. 相似文献
|