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Mugnai S, Pandolfi C, Masi E, Azzarello E, Monetti E, Comparini D, Voigt B, Volkmann D, Mancuso S. Oxidative stress and NO signalling in the root apex as an early response to changes in gravity conditions. BIOMED RESEARCH INTERNATIONAL 2014; 2014:834134. [PMID: 25197662 PMCID: PMC4150467 DOI: 10.1155/2014/834134] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 07/16/2014] [Indexed: 01/02/2023]
Abstract
Oxygen influx showed an asymmetry in the transition zone of the root apex when roots were placed horizontally on ground. The influx increased only in the upper side, while no changes were detected in the division and in the elongation zone. Nitric oxide (NO) was also monitored after gravistimulation, revealing a sudden burst only in the transition zone. In order to confirm these results in real microgravity conditions, experiments have been set up by using parabolic flights and drop tower. The production of reactive oxygen species (ROS) was also monitored. Oxygen, NO, and ROS were continuously monitored during normal and hyper- and microgravity conditions in roots of maize seedlings. A distinct signal in oxygen and NO fluxes was clearly detected only in the apex zone during microgravity, with no significant changes in normal and in hypergravity conditions. The same results were obtained by ROS measurement. The detrimental effect of D'orenone, disrupting the polarised auxin transport, on the onset of the oxygen peaks during the microgravity period was also evaluated. Results indicates an active role of NO and ROS as messengers during the gravitropic response, with probable implications in the auxin redistribution.
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Affiliation(s)
- Sergio Mugnai
- DISPAA, University of Florence, Viale delle Idee 30, 50019 Sesto Fiorentino, Italy
- HSO-USB, ESTEC, European Space Agency, Keplerlaan 1, 2200 AG Noordwijk, The Netherlands
| | - Camilla Pandolfi
- DISPAA, University of Florence, Viale delle Idee 30, 50019 Sesto Fiorentino, Italy
| | - Elisa Masi
- DISPAA, University of Florence, Viale delle Idee 30, 50019 Sesto Fiorentino, Italy
| | - Elisa Azzarello
- DISPAA, University of Florence, Viale delle Idee 30, 50019 Sesto Fiorentino, Italy
| | - Emanuela Monetti
- DISPAA, University of Florence, Viale delle Idee 30, 50019 Sesto Fiorentino, Italy
| | - Diego Comparini
- DISPAA, University of Florence, Viale delle Idee 30, 50019 Sesto Fiorentino, Italy
| | - Boris Voigt
- IZMB, University of Bonn, Kirschallee 1, 53115 Bonn, Germany
| | - Dieter Volkmann
- IZMB, University of Bonn, Kirschallee 1, 53115 Bonn, Germany
| | - Stefano Mancuso
- DISPAA, University of Florence, Viale delle Idee 30, 50019 Sesto Fiorentino, Italy
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252
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Reginato MA, Castagna A, Furlán A, Castro S, Ranieri A, Luna V. Physiological responses of a halophytic shrub to salt stress by Na2SO4 and NaCl: oxidative damage and the role of polyphenols in antioxidant protection. AOB PLANTS 2014; 6:plu042. [PMID: 25063834 PMCID: PMC4153985 DOI: 10.1093/aobpla/plu042] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Salt stress conditions lead to increased production of reactive oxygen species (ROS) in plant cells. Halophytes have the ability to reduce these toxic ROS by means of a powerful antioxidant system that includes enzymatic and non-enzymatic components. In this research, we used the halophytic shrub Prosopis strombulifera to investigate whether the ability of this species to grow under increasing salt concentrations and mixtures was related to the synthesis of polyphenolic compounds and to the maintenance of leaf pigment contents for an adequate photosynthetic activity. Seedlings of P. strombulifera were grown hydroponically in Hoagland's solution, gradually adding Na2SO4 and NaCl separately or in mixtures until reaching final osmotic potentials of -1, -1.9 and -2.6 MPa. Control plants were allowed to develop in Hoagland's solution without salt. Oxidative damage in tissues was determined by H2O2 and malondialdehyde content. Leaf pigment analysis was performed by high-performance liquid chromatography with ultraviolet, and total phenols, total flavonoids, total flavan-3-ols, condensed tannins, tartaric acid esters and flavonols were spectrophotometrically assayed. Treatment with Na2SO4 increased H2O2 production and lipid peroxidation in tissues and induced a sharp increase in flavonoid compounds (mainly flavan-3-ols) and consequently in the antioxidant activity. Also, Na2SO4 treatment induced an increased carotenoid/chlorophyll ratio, which may represent a strategy to protect photosystems against photooxidation. NaCl treatment, however, did not affect H2O2 content, lipid peroxidation, pigments or polyphenols synthesis. The significant accumulation of flavonoids in tissues under Na2SO4 treatment and their powerful antioxidant activity indicates a role for these compounds in counteracting the oxidative damage induced by severe salt stress, particularly, ionic stress. We demonstrate that ionic interactions between different salts in salinized soils modify the biochemical and morpho-physiological responses of P. strombulifera plants to salinity.
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Affiliation(s)
- Mariana A Reginato
- Fisiología Vegetal, Físico Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Argentina
| | - Antonella Castagna
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto, 80 56124 Pisa, Italy
| | - Ana Furlán
- Biología, Fac. de Cs. Exactas, Físico Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Argentina
| | - Stella Castro
- Biología, Fac. de Cs. Exactas, Físico Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Argentina
| | - Annamaria Ranieri
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto, 80 56124 Pisa, Italy
| | - Virginia Luna
- Fisiología Vegetal, Físico Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Argentina
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253
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Li J, Wang Y, Pritchard HW, Wang X. The fluxes of H2O2 and O2 can be used to evaluate seed germination and vigor of Caragana korshinskii. PLANTA 2014; 239:1363-73. [PMID: 24659097 DOI: 10.1007/s00425-014-2049-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 02/19/2014] [Indexed: 05/16/2023]
Abstract
Seed deterioration is detrimental to plant germplasm conservation, and predicting seed germination and vigor with reliability and sensitivity means is urgently needed for practical problems. We investigated the link between hydrogen peroxide (H2O2) flux, oxygen influx and seed vigor of Caragana korshinskii by the non-invasive micro-test technique (NMT). Some related physiological and biochemical changes in seeds were also determined to further explain the changes in the molecular fluxes. The results showed that there was a good linear relationship between germination and H2O2 flux, and that O2 influx was more suitable for assessing seed vigor. H2O2 flux changed relatively little initially, mainly affected by antioxidants (APX, CAT and GSH) and H2O2 content; afterward, the efflux increased more and more rapidly due to high membrane permeability. With the damage of mitochondrial respiration and membrane integrity, O2 influx was gradually reduced. We propose that monitoring H2O2 and O2 fluxes by NMT may be a reliable and sensitive method to evaluate seed germination and vigor.
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254
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Ferreira RA, Duarte JG, Vergine P, Antunes CD, Freire F, Martins-Dias S. Phragmites sp. physiological changes in a constructed wetland treating an effluent contaminated with a diazo dye (DR81). ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2014; 21:9626-9643. [PMID: 24809499 DOI: 10.1007/s11356-014-2988-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Accepted: 04/30/2014] [Indexed: 06/03/2023]
Abstract
The role of Phragmites sp. in phytoremediation of wastewaters containing azo dyes is still, in many ways, at its initial stage of investigation. This plant response to the long-term exposure to a highly conjugated di-azo dye (Direct Red 81, DR81) was assessed using a vertical flow constructed wetland, at pilot scale. A reed bed fed with water was used as control. Changes in photosynthetic pigment content in response to the plant contact with synthetic DR81 effluent highlight Phragmites plasticity. Phragmites leaf enzymatic system responded rapidly to the stress imposed; in general, within 1 day, the up-regulation of foliar reactive oxygen species-scavenging enzymes (especially superoxide dismutase, ascorbate peroxidase (APX), glutathione peroxidase (GPX) and peroxidase) was noticed as plants entered in contact with synthetic DR81 effluent. This prompt activation decreased the endogenous levels of H₂O₂ and the malonyldialdehyde content beyond reference values. Glutathione S-transferase (GST) activity intensification was not enough to cope with stress imposed by DR81. GPX activity was pivotal for the detoxification pathways after a 24-h exposure. Carotenoid pool was depleted during this shock. After the imposed DR81 stress, plants were harvested. In the next vegetative cycle, Phragmites had already recovered from the chemical stress. Principal component analysis (PCA) highlights the role of GPX, GST, APX, and carotenoids along catalase (CAT) in the detoxification process.
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Affiliation(s)
- Renata Alexandra Ferreira
- IBB-Institute for Biotechnology and Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av Rovisco Pais, 1049-001 Lisboa, Portugal
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255
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Bárzana G, Aroca R, Bienert GP, Chaumont F, Ruiz-Lozano JM. New insights into the regulation of aquaporins by the arbuscular mycorrhizal symbiosis in maize plants under drought stress and possible implications for plant performance. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2014; 27:349-63. [PMID: 24593244 DOI: 10.1094/mpmi-09-13-0268-r] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The relationship between modulation by arbuscular mycorrhizae (AM) of aquaporin expression in the host plant and changes in root hydraulic conductance, plant water status, and performance under stressful conditions is not well known. This investigation aimed to elucidate how the AM symbiosis modulates the expression of the whole set of aquaporin genes in maize plants under different growing and drought stress conditions, as well as to characterize some of these aquaporins in order to shed further light on the molecules that may be involved in the mycorrhizal responses to drought. The AM symbiosis regulated a wide number of aquaporins in the host plant, comprising members of the different aquaporin subfamilies. The regulation of these genes depends on the watering conditions and the severity of the drought stress imposed. Some of these aquaporins can transport water and also other molecules which are of physiological importance for plant performance. AM plants grew and developed better than non-AM plants under the different conditions assayed. Thus, for the first time, this study relates the well-known better performance of AM plants under drought stress to not only the water movement in their tissues but also the mobilization of N compounds, glycerol, signaling molecules, or metalloids with a role in abiotic stress tolerance. Future studies should elucidate the specific function of each aquaporin isoform regulated by the AM symbiosis in order to shed further light on how the symbiosis alters the plant fitness under stressful conditions.
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256
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Zhang JJ, Lu YC, Zhang JJ, Tan LR, Yang H. Accumulation and toxicological response of atrazine in rice crops. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2014; 102:105-12. [PMID: 24530725 DOI: 10.1016/j.ecoenv.2013.12.034] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 11/30/2013] [Accepted: 12/04/2013] [Indexed: 05/18/2023]
Abstract
Atrazine is one of the most widely used herbicides for controlling weeds and grasses. Due to its intensive use, it has become a serious contaminant in soil and water. To evaluate impact of atrazine on graminaceous crops, experiments focusing on atrazine accumulation and toxic response in rice (Oryza sativa) were carried out. Treatment with atrazine at 0.05-0.8 mg L(-1) for 6 d reduced elongation of shoot and root. Compared with a mock treatment, the elongation of shoot with atrazine was 67.1 percent of the control, whereas that of root was 79.5 percent, indicating that the shoot was more affected than the root. Atrazine was readily absorbed by rice from media. Although the quantitative absorption of atrazine was positively correlated with the external supply of the herbicide, translocation of atrazine from roots to the above-ground was reduced from 39.88±6.26 (at 0.05 mg L(-1)) to 9.25±0.27 (0.8 mg L(-1)). While accumulation of atrazine in rice plants led to toxic responses such as over-generation of hydrogen peroxide and superoxide anions, it triggered the plant defense system against the herbicide-induced oxidative stress. This was best presented by the enhanced activities of several antioxidant enzymes (e.g. superoxide dismutase, catalase and peroxidase) and expression of genes responsible for the tolerance to atrazine toxicity.
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Affiliation(s)
- Jia Jun Zhang
- Jiangsu Key Laboratory of Pesticide Science, College of Science, Nanjing Agricultural University, Nanjing 210095, China; Department of Pharmacy, Tongren Polytechnic, Tongren, China
| | - Yi Chen Lu
- Jiangsu Key Laboratory of Pesticide Science, College of Science, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China
| | - Jin Jin Zhang
- Jiangsu Key Laboratory of Pesticide Science, College of Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Li Rong Tan
- Jiangsu Key Laboratory of Pesticide Science, College of Science, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China
| | - Hong Yang
- Jiangsu Key Laboratory of Pesticide Science, College of Science, Nanjing Agricultural University, Nanjing 210095, China.
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257
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Wu QS, Zou YN, Fathi Abd-Allah E. Mycorrhizal Association and ROS in Plants. OXIDATIVE DAMAGE TO PLANTS 2014:453-475. [DOI: 10.1016/b978-0-12-799963-0.00015-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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258
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Vicente CSL, Ikuyo Y, Mota M, Hasegawa K. Pinewood nematode-associated bacteria contribute to oxidative stress resistance of Bursaphelenchus xylophilus. BMC Microbiol 2013; 13:299. [PMID: 24365493 PMCID: PMC3880045 DOI: 10.1186/1471-2180-13-299] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 12/18/2013] [Indexed: 12/21/2022] Open
Abstract
Background Pine wilt disease (PWD) caused by the pinewood nematode Bursaphelenchus xylophilus is one of the most serious forest diseases in the world. The role of B. xylophilus-associated bacteria in PWD and their interaction with the nematode, have recently been under substantial investigation. Several studies report a potential contribution of the bacteria for the PWD development, either as a helper to enhance the pathogenicity of the nematode or as a pathogenic agent expressing interesting traits related to lifestyle host-adaptation. Results We investigated the nematode-bacteria interaction under a severe oxidative stress (OS) condition using a pro-oxidant hydrogen peroxide and explored the adhesion ability of these bacteria to the cuticle surface of the nematodes. Our results clearly demonstrated a beneficial effect of the Serratia spp. (isolates LCN-4, LCN-16 and PWN-146) to B. xylophilus under the OS condition. Serratia spp. was found to be extremely OS-resistant, and promote survival of B. xylophilus and down-regulate two B. xylophilus catalase genes (Bxy-ctl-1 and Bxy-ctl-2). In addition, we show that the virulent isolate (Ka4) of B. xylophilus survives better than the avirulent (C14-5) isolate under the OS condition. The bacterial effect was transverse for both B. xylophilus isolates. We could not observe a strong and specific adhesion of these bacteria on the B. xylophilus cuticle surface. Conclusions We report, for the first time, that B. xylophilus associated bacteria may assist the nematode opportunistically in the disease, and that a virulent B. xylophilus isolate displayed a higher tolerance towards the OS conditions than an avirulent isolate.
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Affiliation(s)
| | | | | | - Koichi Hasegawa
- Department of Environmental Biology, College of Bioscience & Biotechnology, Chubu University, 1200 Matsumoto, Kasugai, Aichi 487-8501, Japan.
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259
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Pellegrini E, Trivellini A, Campanella A, Francini A, Lorenzini G, Nali C, Vernieri P. Signaling molecules and cell death in Melissa officinalis plants exposed to ozone. PLANT CELL REPORTS 2013; 32:1965-1980. [PMID: 24081611 DOI: 10.1007/s00299-013-1508-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 09/13/2013] [Accepted: 09/16/2013] [Indexed: 05/27/2023]
Abstract
The study focuses on the interaction between reactive oxygen species and hormones that regulate the programmed cell death in plants of Melissa officinalis exposed to ozone. Interaction between hormone and redox signaling pathways has been investigated in ozone-stressed (200 ppb, 5 h) lemon balm to verify if the response resembles the biotic defense reactions. In comparison to controls, plants exhibited foliar injury and the cell death was induced by (1) biphasic production of hydrogen peroxide and superoxide radical; (2) hormonal regulation of ozone-induced lesion formation with a significant production of ethylene, salicylic, jasmonic and abscisic acid; (3) ozone degradation to reactive oxygen species and their detoxification by some enzymatic (such as superoxide dismutase) and non-enzymatic antioxidant systems (such as ascorbic acid, glutathione and carotenoids), that worked in cooperation without providing a defense against free radicals (such as confirmed by the modification of the antioxidant properties of leaf tissue). This integrated view showed that reactive oxygen species interact with hormonal signaling pathway regulating cell death and the sensitivity of lemon balm to ozone.
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Affiliation(s)
- Elisa Pellegrini
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, 56124, Pisa, Italy
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260
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Delporte F, Muhovski Y, Pretova A, Watillon B. Analysis of expression profiles of selected genes associated with the regenerative property and the receptivity to gene transfer during somatic embryogenesis in Triticum aestivum L. Mol Biol Rep 2013; 40:5883-906. [PMID: 24078158 PMCID: PMC3825128 DOI: 10.1007/s11033-013-2696-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 09/14/2013] [Indexed: 12/26/2022]
Abstract
The physiological, biochemical and molecular mechanisms regulating the initiation of a regenerative pathway remain partially unknown. Efforts to identify the biological features that confer transformation ability, or the tendency of some cells to induce transgene silencing, would help to improve plant genetic engineering. The objective of our study was to monitor the evolution of plant cell competencies in relation to both in vitro tissue culture regeneration and the genetic transformation properties. We used a simple wheat regeneration procedure as an experimental model for studying the regenerative capacity of plant cells and their receptivity to direct gene transfer over the successive steps of the regenerative pathway. Target gene profiling studies and biochemical assays were conducted to follow some of the mechanisms triggered during the somatic-to-embryogenic transition (i.e. dedifferentiation, cell division activation, redifferentiation) and affecting the accessibility of plant cells to receive and stably express the exogenous DNA introduced by bombardment. Our results seem to indicate that the control of cell-cycle (S-phase) and host defense strategies can be crucial determinants of genetic transformation efficiency. The results from studies conducted at macro-, micro- and molecular scales are then integrated into a holistic approach that addresses the question of tissue culture and transgenesis competencies more broadly. Through this multilevel analysis we try to establish functional links between both regenerative capacity and transformation receptiveness, and thereby to provide a more global and integrated vision of both processes, at the core of defense/adaptive mechanisms and survival, between undifferentiated cell proliferation and organization.
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Affiliation(s)
- Fabienne Delporte
- Department of Life Sciences, Bioengineering Unit, Walloon Agricultural Research Centre (CRAw), Chaussée de Charleroi 234, 5030 Gembloux, Belgium
| | - Yordan Muhovski
- Department of Life Sciences, Bioengineering Unit, Walloon Agricultural Research Centre (CRAw), Chaussée de Charleroi 234, 5030 Gembloux, Belgium
| | - Anna Pretova
- Institute of Plant Genetics and Biotechnology, Slovak Academy of Sciences, Akademicka 2, P.O. Box 39 A, 950 07 Nitra, Slovakia
| | - Bernard Watillon
- Department of Life Sciences, Bioengineering Unit, Walloon Agricultural Research Centre (CRAw), Chaussée de Charleroi 234, 5030 Gembloux, Belgium
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261
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Ha MH, Pflugmacher S. Time-dependent alterations in growth, photosynthetic pigments and enzymatic defense systems of submerged Ceratophyllum demersum during exposure to the cyanobacterial neurotoxin anatoxin-a. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2013; 138-139:26-34. [PMID: 23685387 DOI: 10.1016/j.aquatox.2013.04.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 04/05/2013] [Accepted: 04/13/2013] [Indexed: 06/02/2023]
Abstract
Recently, aquatic macrophytes have been considered as promising tools for eco-friendly water management with a low running cost. However, only little information is available thus far regarding the metabolic capacity of macrophytes for coping with cyanobacterial toxins (cyanotoxins) in the aquatic environment. Cyanotoxins have become emerging contaminants of great concern due to the high proliferation of cyanobacteria (cyanobacterial bloom) accelerated by eutrophication and climate change. Anatoxin-a, one of the common and major cyanotoxins, is suggested as a high priority water pollutant for regulatory consideration owing to its notoriously rapid mode of action as a neurotoxin. In this study, the time-course metabolic regulation of the submerged macrophyte Ceratophyllum demersum (C. demersum) was investigated during exposure to anatoxin-a at an environmentally relevant concentration (15 μg/L). Biotransformation and antioxidative systems in C. demersum responded positively to anatoxin-a through the promoted synthesis of most of the involved enzymes within 8h. Maximum enzyme activities were exhibited after 24 or 48 h of exposure to anatoxin-a. However, an apparent decline in enzyme activities was also observed at longer exposure duration (168 and 336 h) in company with high steady-state levels of cell internal H₂O₂, which showed its highest level after 48 h. Meanwhile, irreversible inhibitory influence on chlorophyll content (vitality) was noticed, whereas the ratio of carotenoids to total chlorophyll was increased with the increase in exposure duration. Consequently, the reduction in growth (biomass) of C. demersum was observed in sub-chronic exposure to anatoxin-a (8 weeks). Overall results clearly indicate, on the one hand, that anatoxin-a causes negative allelopathic effects on the macrophyte by inducing oxidative stress. On the other hand, the macrophyte might have interactions with anatoxin-a, based on the prompt reaction of its enzymatic defense systems to the toxin. The result obtained from the present study could contribute to the improvement of basic knowledge about the ecological impact of anatoxin-a and the environmental fate of the toxin in the aquatic environment.
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Affiliation(s)
- Mi-Hee Ha
- Berlin Institute of Technology-BIT, Department of Ecotoxicological Impact Research and Ecotoxicology, Ernst-Reuter-Platz 1, 10587 Berlin, Germany
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262
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Ibrahim MH, Jaafar HZE. Abscisic acid induced changes in production of primary and secondary metabolites, photosynthetic capacity, antioxidant capability, antioxidant enzymes and lipoxygenase inhibitory activity of Orthosiphon stamineus Benth. Molecules 2013; 18:7957-76. [PMID: 23884129 PMCID: PMC6270447 DOI: 10.3390/molecules18077957] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 07/03/2013] [Accepted: 07/03/2013] [Indexed: 11/16/2022] Open
Abstract
An experiment was conducted to investigate and distinguish the relationships in the production of total phenolics, total flavonoids, soluble sugars, H2O2, O2-, phenylalanine ammonia lyase (PAL) activity, leaf gas exchange, antioxidant activity, antioxidant enzyme activity [ascorbate peroxidase (APX), catalase (CAT), superoxide dismutase (SOD) and Lipoxygenase inhibitory activity (LOX)] under four levels of foliar abscisic acid (ABA) application (0, 2, 4, 6 µM) for 15 weeks in Orthosiphon stamineus Benth. It was found that the production of plant secondary metabolites, soluble sugars, antioxidant activity, PAL activity and LOX inhibitory activity was influenced by foliar application of ABA. As the concentration of ABA was increased from 0 to 6 µM the production of total phenolics, flavonoids, sucrose, H2O2, O2-, PAL activity and LOX inhibitory activity was enhanced. It was also observed that the antioxidant capabilities (DPPH and ORAC) were increased. This was followed by increases in production of antioxidant enzymes APX, CAT and SOD. Under high application rates of ABA the net photosynthesis and stomatal conductance was found to be reduced. The production of primary and secondary metabolites displayed a significant positive relationship with H2O2 (total phenolics, r2 = 0.877; total flavonoids, r2 = 0.812; p ≤ 0.05) and O2- (total phenolics, r2 = 0.778; total flavonoids, r2 = 0.912; p ≤ 0.05). This indicated that increased oxidative stress at high application rates of ABA, improved the production of phytochemicals.
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Affiliation(s)
- Mohd Hafiz Ibrahim
- Department of Biology, Faculty of Science, University Putra Malaysia, 43400 Serdang, Selangor, Malaysia
| | - Hawa Z. E. Jaafar
- Department of Crop Science, Faculty of Agriculture, University Putra Malaysia, 43400 Serdang, Selangor, Malaysia; E-Mail:
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263
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Yuan HM, Liu WC, Jin Y, Lu YT. Role of ROS and auxin in plant response to metal-mediated stress. PLANT SIGNALING & BEHAVIOR 2013; 8:e24671. [PMID: 23603941 PMCID: PMC3906317 DOI: 10.4161/psb.24671] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Being unable to move away from their places of germination, in order to avoid excess metal-induced damages, plants have to evolve different strategies and complex regulatory mechanisms to survive harsh conditions. While both ROS and auxin are documented to be important in plant response to metal stress, the mechanisms underlying the crosstalk between ROS and auxin in metal stress are poorly understood. In this review, we provide an update on the regulation of plant responses to metal-stress by ROS and auxin signaling pathways, primarily, with a focus on the copper, aluminum and cadmium stress. We aim at surveying the mechanisms underlying how metal stress modulates the changes in auxin distribution and the network of ROS and auxin in plant response to metal stress based on recent studies.
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264
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Yao Y, Liu X, Li Z, Ma X, Rennenberg H, Wang X, Li H. Drought-induced H2O 2 accumulation in subsidiary cells is involved in regulatory signaling of stomatal closure in maize leaves. PLANTA 2013; 238:217-27. [PMID: 23625015 DOI: 10.1007/s00425-013-1886-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2012] [Accepted: 04/15/2013] [Indexed: 05/23/2023]
Abstract
Increasing H2O2 levels in guard cells in response to environmental stimuli are recently considered a general messenger involved in the signaling cascade for the induction of stomatal closure. But little is known as to whether subsidiary cells participate in the H2O2-mediated stomatal closure of grass plants. In the present study, 2-week-old seedlings of maize (Zea mays) were exposed to different degrees of soil water deficit for 3 weeks. The effects of soil water contents on leaf ABA and H2O2 levels and stomatal aperture were investigated using physiological, biochemical, and histochemical approaches. The results showed that even under well-watered conditions, significant amounts of H2O2 were observed in guard cells, whereas H2O2 concentrations in the subsidiary cells were negligible. Decreasing soil water contents led to a significant increase in leaf ABA levels associated with significantly enhanced O2 (-) and H2O2 contents, consistent with reduced degrees of stomatal conductance and aperture. The significant increase in H2O2 appeared in both guard cells and subsidiary cells of the stomatal complex, and H2O2 levels increased with decreasing soil water contents. Drought-induced increase in the activity of antioxidative enzymes could not counteract the significant increase in H2O2 levels in guard cells and subsidiary cells. These results indicate that subsidiary cells participate in H2O2-mediated stomatal closure, and drought-induced H2O2 accumulation in subsidiary cells is involved in the signaling cascade regulating stomatal aperture of grass plants such as maize.
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Affiliation(s)
- Yaqin Yao
- College of Life Science, Northwest A&F University, Yangling, Shaanxi, China
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265
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Simon UK, Polanschütz LM, Koffler BE, Zechmann B. High resolution imaging of temporal and spatial changes of subcellular ascorbate, glutathione and H₂O₂ distribution during Botrytis cinerea infection in Arabidopsis. PLoS One 2013; 8:e65811. [PMID: 23755284 PMCID: PMC3673919 DOI: 10.1371/journal.pone.0065811] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Accepted: 05/03/2013] [Indexed: 11/23/2022] Open
Abstract
In order to study the mechanisms behind the infection process of the necrotrophic fungus Botrytis cinerea, the subcellular distribution of hydrogen peroxide (H₂O₂) was monitored over a time frame of 96 h post inoculation (hpi) in Arabidopsis thaliana Col-0 leaves at the inoculation site (IS) and the area around the IS which was defined as area adjacent to the inoculation site (AIS). H₂O₂ accumulation was correlated with changes in the compartment-specific distribution of ascorbate and glutathione and chloroplast fine structure. This study revealed that the severe breakdown of the antioxidative system, indicated by a drop in ascorbate and glutathione contents at the IS at later stages of infection correlated with an accumulation of H₂O₂ in chloroplasts, mitochondria, cell walls, nuclei and the cytosol which resulted in the development of chlorosis and cell death, eventually visible as tissue necrosis. A steady increase of glutathione contents in most cell compartments within infected tissues (up to 600% in chloroplasts at 96 hpi) correlated with an accumulation of H₂O₂ in chloroplasts, mitochondria and cell walls at the AIS indicating that high glutathione levels could not prevent the accumulation of reactive oxygen species (ROS) which resulted in chlorosis. Summing up, this study reveals the intracellular sequence of events during Botrytis cinerea infection and shows that the breakdown of the antioxidative system correlated with the accumulation of H₂O₂ in the host cells. This resulted in the degeneration of the leaf indicated by severe changes in the number and ultrastructure of chloroplasts (e.g. decrease of chloroplast number, decrease of starch and thylakoid contents, increase of plastoglobuli size), chlorosis and necrosis of the leaves.
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Affiliation(s)
- Uwe K. Simon
- Institute of Plant Sciences, University of Graz, Graz, Austria
| | | | | | - Bernd Zechmann
- Institute of Plant Sciences, University of Graz, Graz, Austria
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266
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Chiesa MA, Siciliano MF, Ornella L, Roeschlin RA, Favaro MA, Delgado NP, Sendín LN, Orce IG, Ploper LD, Vojnov AA, Vacas JG, Filippone MP, Castagnaro AP, Marano MR. Characterization of a variant of Xanthomonas citri subsp. citri that triggers a host-specific defense response. PHYTOPATHOLOGY 2013; 103:555-564. [PMID: 23268580 DOI: 10.1094/phyto-11-12-0287-r] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Citrus is an economically important fruit crop that is severely afflicted by Asiatic citrus bacterial canker (CBC), a disease caused by the phytopathogen Xanthomonas citri subsp. citri (X. citri). To gain insight into the molecular epidemiology of CBC, 42 Xanthomonas isolates were collected from a range of Citrus spp. across 17 different orchards in Tucumán, Argentina and subjected to molecular, biochemical, and pathogenicity tests. Analysis of genome-specific X. citri markers and DNA polymorphisms based on repetitive elements-based polymerase chain reaction showed that all 42 isolates belonged to X. citri. Interestingly, pathogenicity tests showed that one isolate, which shares >90% genetic similarity to the reference strain X. citri T, has host range specificity. This new variant of X. citri subsp. citri, named X. citri A(T), which is deficient in xanthan production, induces an atypical, noncankerous chlorotic phenotype in Citrus limon and C. paradisi and weak cankerous lesions in C. aurantifolia and C. clementina leaves. In C. limon, suppression of canker development is concomitant with an oxidative burst; xanthan is not implicated in the phenotype induced by this interaction, suggesting that other bacterial factors would be involved in triggering the defense response.
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Affiliation(s)
- María A Chiesa
- Instituto de Biología Molecular y Celular de Rosario (IBR)–Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Área Virología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 590, S2002LRK Rosario, Argentina
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267
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Vera-Reyes I, Huerta-Heredia AA, Ponce-Noyola T, Flores-Sanchez IJ, Esparza-García F, Cerda-García-Rojas CM, Trejo-Tapia G, Ramos-Valdivia AC. Strictosidine-related enzymes involved in the alkaloid biosynthesis ofUncaria tomentosaroot cultures grown under oxidative stress. Biotechnol Prog 2013; 29:621-30. [DOI: 10.1002/btpr.1723] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 02/07/2013] [Indexed: 11/11/2022]
Affiliation(s)
- Ileana Vera-Reyes
- Depto. de Biotecnología y Biongeniería; Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN); A. P. 14-740, México, D. F. 07000, Mexico
| | - Ariana A. Huerta-Heredia
- Depto. de Biotecnología y Biongeniería; Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN); A. P. 14-740, México, D. F. 07000, Mexico
| | - Teresa Ponce-Noyola
- Depto. de Biotecnología y Biongeniería; Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN); A. P. 14-740, México, D. F. 07000, Mexico
| | - Isvett Josefina Flores-Sanchez
- Depto. de Biotecnología y Biongeniería; Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN); A. P. 14-740, México, D. F. 07000, Mexico
| | - Fernando Esparza-García
- Depto. de Biotecnología y Biongeniería; Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN); A. P. 14-740, México, D. F. 07000, Mexico
| | - Carlos M. Cerda-García-Rojas
- Depto. de Química; Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN); A. P. 14-740, México, D. F. 07000, Mexico
| | - Gabriela Trejo-Tapia
- Depto. de Biotecnología; Centro de Desarrollo de Productos Bióticos, Instituto Politécnico Nacional (CEPROBI-IPN); P.O. Box 24 62730, Yautepec Morelos México
| | - Ana C. Ramos-Valdivia
- Depto. de Biotecnología y Biongeniería; Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN); A. P. 14-740, México, D. F. 07000, Mexico
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268
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Piattoni CV, Guerrero SA, Iglesias AA. A differential redox regulation of the pathways metabolizing glyceraldehyde-3-phosphate tunes the production of reducing power in the cytosol of plant cells. Int J Mol Sci 2013; 14:8073-92. [PMID: 23584025 PMCID: PMC3645732 DOI: 10.3390/ijms14048073] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Revised: 03/02/2013] [Accepted: 03/07/2013] [Indexed: 11/28/2022] Open
Abstract
Adaptation to aerobic life leads organisms to sense reactive oxygen species and use the signal for coordination of the entire metabolism. Glycolysis in plants is a particular network where specific steps, like oxidation of glyceraldehydes-3-phosphate (Ga3P), are critical in order for it to function. The triose-phosphate can be converted into 3-phosphoglycerate through the phosphorylating Ga3P dehydrogenase (Ga3PDHase, EC 1.2.1.12) producing ATP and NADH, or via the non-phosphorylating enzyme (np-Ga3PDHase; EC 1.2.1.9) generating NADPH. In this work we found redox regulation to be a posttranslational mechanism allowing the fine-tuning of the triose-phosphate fate. Both enzymes were inactivated after oxidation by reactive oxygen and nitrogen species. Kinetic studies determined that Ga3PDHase is marked (63-fold) more sensitive to oxidants than np-Ga3PDHase. Thioredoxin-h reverted the oxidation of both enzymes (although with differences between them), suggesting a physiological redox regulation. The results support a metabolic scenario where the cytosolic triose-phosphate dehydrogenases are regulated under changeable redox conditions. This would allow coordinate production of NADPH or ATP through glycolysis, with oxidative signals triggering reducing power synthesis in the cytosol. The NADPH increment would favor antioxidant responses to cope with the oxidative situation, while the thioredoxin system would positively feedback NADPH production by maintaining np-Ga3PDHase at its reduced active state.
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Affiliation(s)
- Claudia V Piattoni
- Instituto de Agrobiotecnología del Litoral (IAL, CONICET-UNL), FBCB, Paraje "El Pozo", CC 242, Santa Fe S3000ZAA, Argentina.
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269
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Zhang Z, Zhang Q, Wu J, Zheng X, Zheng S, Sun X, Qiu Q, Lu T. Gene knockout study reveals that cytosolic ascorbate peroxidase 2(OsAPX2) plays a critical role in growth and reproduction in rice under drought, salt and cold stresses. PLoS One 2013; 8:e57472. [PMID: 23468992 PMCID: PMC3585366 DOI: 10.1371/journal.pone.0057472] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Accepted: 01/22/2013] [Indexed: 11/18/2022] Open
Abstract
Plant ascorbate peroxidases (APXs), enzymes catalyzing the dismutation of H2O2 into H2O and O2, play an important role in reactive oxygen species homeostasis in plants. The rice genome has eight OsAPXs, but their physiological functions remain to be determined. In this report, we studied the function of OsAPX2 gene using a T-DNA knockout mutant under the treatment of drought, salt and cold stresses. The Osapx2 knockout mutant was isolated by a genetic screening of a rice T-DNA insertion library under 20% PEG-2000 treatment. Loss of function in OsAPX2 affected the growth and development of rice seedlings, resulting in semi-dwarf seedlings, yellow-green leaves, leaf lesion mimic and seed sterility. OsAPX2 expression was developmental- and spatial-regulated, and was induced by drought, salt, and cold stresses. Osapx2 mutants had lower APX activity and were sensitive to abiotic stresses; overexpression of OsAPX2 increased APX activity and enhanced stress tolerance. H2O2 and MDA levels were high in Osapx2 mutants but low in OsAPX2-OX transgenic lines relative to wild-type plants after stress treatments. Taken together, the cytosolic ascorbate peroxidase OsAPX2 plays an important role in rice growth and development by protecting the seedlings from abiotic stresses through scavenging reactive oxygen species.
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Affiliation(s)
- Zhiguo Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences/National Key facility for Gene Resources And Genetic Improvement, Beijing, China
| | - Quian Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences/National Key facility for Gene Resources And Genetic Improvement, Beijing, China
| | - Jinxia Wu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences/National Key facility for Gene Resources And Genetic Improvement, Beijing, China
| | - Xia Zheng
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences/National Key facility for Gene Resources And Genetic Improvement, Beijing, China
| | - Sheng Zheng
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Xuehui Sun
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences/National Key facility for Gene Resources And Genetic Improvement, Beijing, China
| | - Quansheng Qiu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
- * E-mail: (QQ); (TL)
| | - Tiegang Lu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences/National Key facility for Gene Resources And Genetic Improvement, Beijing, China
- * E-mail: (QQ); (TL)
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270
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Hieno A, Naznin HA, Sawaki K, Koyama H, Sakai Y, Ishino H, Hyakumachi M, Yamamoto YY. Analysis of environmental stress in plants with the aid of marker genes for H2O2 responses. Methods Enzymol 2013; 527:221-37. [PMID: 23830634 DOI: 10.1016/b978-0-12-405882-8.00012-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Hydrogen peroxide acts as a signaling molecule mediating the acquisition of tolerance to both biotic and abiotic stresses. Identification of marker genes for H2O2 response could help to intercept the signaling network of stress response of plants. Here, we describe application of marker genes for H2O2 responses to monitoring several abiotic stress responses. Arabidopsis plants were treated with UV-B, high light, and cold stresses, where involvement of H2O2-mediated signaling is known or suggested. Monitoring of these stress responses with molecular markers using quantitative real-time RT-PCR can detect landmark events in the sequential stress responses. These methods can be used for analysis of mutants and transgenic plants to examine natural H2O2 responses that are involved in environmental adaptation.
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Affiliation(s)
- Ayaka Hieno
- The United Graduate School of Agricultural Sciences, Gifu University, Gifu, Japan
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271
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Regulation of Leaf Senescence: Role of Reactive Oxygen Species. PLASTID DEVELOPMENT IN LEAVES DURING GROWTH AND SENESCENCE 2013. [DOI: 10.1007/978-94-007-5724-0_17] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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272
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Abstract
Ultraviolet (UV) radiation can cause stresses or act as a photoregulatory signal depending on its wavelengths and fluence rates. Although the most harmful effects of UV on living cells are generally attributed to UV-B radiation, UV-A radiation can also affect many aspects of cellular processes. In cyanobacteria, most studies have concentrated on the damaging effect of UV and defense mechanisms to withstand UV stress. However, little is known about the activation mechanism of signaling components or their pathways which are implicated in the process following UV irradiation. Motile cyanobacteria use a very precise negative phototaxis signaling system to move away from high levels of solar radiation, which is an effective escape mechanism to avoid the detrimental effects of UV radiation. Recently, two different UV-A-induced signaling systems for regulating cyanobacterial phototaxis were characterized at the photophysiological and molecular levels. Here, we review the current understanding of the UV-A mediated signaling pathways in the context of the UV-A perception mechanism, early signaling components, and negative phototactic responses. In addition, increasing evidences supporting a role of pterins in response to UV radiation are discussed. We outline the effect of UV-induced cell damage, associated signaling molecules, and programmed cell death under UV-mediated oxidative stress.
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273
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Debona D, Rodrigues FÁ, Rios JA, Nascimento KJT. Biochemical changes in the leaves of wheat plants infected by Pyricularia oryzae. PHYTOPATHOLOGY 2012; 102:1121-9. [PMID: 22913412 DOI: 10.1094/phyto-06-12-0125-r] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Blast, caused by the fungus Pyricularia oryzae, is a major disease of the wheat crop in the Brazilian Cerrado and represents a potential threat to world wheat production. However, information about the wheat-P. oryzae interaction is still limited. In this work, the activities of the enzymes superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), glutathione-S-transferase (GST), ascorbate peroxidase (APX), glutathione reductase (GR), and glutathione peroxidase (GPX) and the concentrations of superoxide (O₂(-)), hydrogen peroxide (H₂O₂), and malondialdehyde (MDA) as well as the electrolyte leakage (EL) were studied in wheat plants 'BR 18' and 'BRS 229', which are susceptible and partially resistant, respectively, to leaf blast at the vegetative growth stage, during the infection process of P. oryzae. The blast severity in BRS 229 was 50% lower than in BR 18 at 96 h after inoculation (hai). The activities of SOD, POX, APX, and GST increased for both cultivars in the inoculated plants compared with noninoculated plants and the increases were more pronounced for BRS 229 than for BR 18 at 96 hai. The GR and CAT activities only increased in inoculated plants from BRS 229 at 96 hai. For BR 18, the GR activity was not influenced by plant inoculation, and the CAT activity was lower in inoculated plants. The GPX activity only increased in inoculated plants from BR 18 at 48 and 72 hai. The P. oryzae infection increased the O₂(-), H₂O₂, and MDA concentrations and EL. However, the greater increases of the SOD, POX, APX, GST, GR, and CAT activities for BRS 229 compared with BR 18 contributed to the lower O₂(-), H₂O₂, and MDA concentrations and EL verified in the former. These results show that a more efficient antioxidative system in the removal of excess of reactive oxygen species generated during the infection process of P. oryzae limits the cellular damage caused by the fungus, thus contributing to greater wheat resistance to blast.
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Affiliation(s)
- Daniel Debona
- Viçosa Federal University, Department of Plant Pathology, Laboratory of Host-Parasite Interaction, Barzil
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274
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Shao X, Zhu Y, Cao S, Wang H, Song Y. Soluble Sugar Content and Metabolism as Related to the Heat-Induced Chilling Tolerance of Loquat Fruit During Cold Storage. FOOD BIOPROCESS TECH 2012. [DOI: 10.1007/s11947-012-1011-6] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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275
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Ribeiro CW, Carvalho FEL, Rosa SB, Alves-Ferreira M, Andrade CMB, Ribeiro-Alves M, Silveira JAG, Margis R, Margis-Pinheiro M. Modulation of genes related to specific metabolic pathways in response to cytosolic ascorbate peroxidase knockdown in rice plants. PLANT BIOLOGY (STUTTGART, GERMANY) 2012; 14:944-955. [PMID: 22686276 DOI: 10.1111/j.1438-8677.2012.00587.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
As a central component of the hydrogen peroxide detoxifying system in plant cells, ascorbate peroxidases (APX) play an essential role in the control of intracellular reactive oxygen species (ROS) levels. To characterise the function of cytosolic APX isoforms (OsAPX1 and OsAPX2) in the mechanisms of plant defence, OsAPX1/2 knockdown rice plants were previously obtained. OsAPX1/2 knockdown plants (APx1/2s) exhibited a normal phenotype and development, even though they showed a global reduction of APX activity and increased hydrogen peroxide accumulation. To understand how rice plants compensate for the deficiency of cytosolic APX, expression and proteomic analyses were performed to characterise the global expression pattern of the APx1/2s mutant line compared with non-transformed plants. Our results strongly suggest that deficiencies in cytosolic APX isoforms markedly alter expression of genes associated with several key metabolic pathways, especially of genes involved in photosynthesis and antioxidant defence. These metabolic changes are compensatory because central physiological processes such as photosynthesis and growth were similar to non-transformed rice plants. Our analyses showed modulation of groups of genes and proteins related to specific metabolic pathways. Among the differentially expressed genes, the largest number corresponded to those with catalytic activity. Genes related to oxidative stress, carbohydrate metabolism, photosynthesis and transcription factor-encoding genes were also modulated. These results represent an important step toward understanding of the role played by cytosolic APX isoforms and hydrogen peroxide in the regulation of metabolism by redox modulation in monocots.
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Affiliation(s)
- C W Ribeiro
- Biotechnology Center, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
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276
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Choudhary R, Saroha AE, Swarnkar PL. Effect of abscisic acid and hydrogen peroxide on antioxidant enzymes in Syzygium cumini plant. JOURNAL OF FOOD SCIENCE AND TECHNOLOGY 2012; 49:649-52. [PMID: 24082280 PMCID: PMC3550844 DOI: 10.1007/s13197-011-0464-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 06/23/2011] [Accepted: 07/05/2011] [Indexed: 12/01/2022]
Abstract
The present study was undertaken to study the effect of abscisic acid and hydrogen peroxide on the activities of antioxidant enzymes namely superoxide dismutase (SOD; E.C. 1.15.1.1), catalase (CAT; E.C. 1.11.1.6) and ascorbate peroxidase (APX; E.C. 1.11.1.11) in Syzygium cumini plant. The varying concentrations of ABA (2-8 mM/l) and H2O2 (2-8 mM/l) modulated enzyme activities differently. In general, some concentrations of the ABA and H2O2 stimulated the activities of all the three enzymes except that there was a dose dependent reduction in catalase activity in the plants treated with ABA.
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Affiliation(s)
- Ramkishan Choudhary
- Department of Botany, University of Rajasthan, Jaipur, 302004 Rajasthan India
| | - Ajaya Eesha Saroha
- Department of Botany, University of Rajasthan, Jaipur, 302004 Rajasthan India
| | - P. L. Swarnkar
- Department of Botany, University of Rajasthan, Jaipur, 302004 Rajasthan India
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277
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Hernandez M, Fernandez-Garcia N, Garcia-Garma J, Rubio-Asensio JS, Rubio F, Olmos E. Potassium starvation induces oxidative stress in Solanum lycopersicum L. roots. JOURNAL OF PLANT PHYSIOLOGY 2012; 169:1366-74. [PMID: 22771251 DOI: 10.1016/j.jplph.2012.05.015] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 03/01/2012] [Accepted: 05/14/2012] [Indexed: 05/09/2023]
Abstract
The relationship between potassium deficiency and the antioxidative defense system has received little study. The aim of this work was to study the induction of oxidative stress in response to K(+) deficiency and the putative role of antioxidants. The tomato plants were grown in hydroponic systems to determine the role of reactive oxygen species (ROS) in the root response to potassium deprivation. Parameters of oxidative stress (malondialdehyde and hydrogen peroxide (H(2)O(2)) concentration), activities of antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR) and glutathione reductase (GR)) and antioxidant molecules (ascorbate (ASC) and glutathione) were investigated. H(2)O(2) was subcellularly located by laser confocal microscopy after potassium starvation in roots. During the first 24h, H(2)O(2) induced the cascade of the cellular response to low potassium, and ROS accumulation was located mainly in epidermal cells in the elongation zone and meristematic cells of the root tip and the epidermal cells of the mature zones of potassium starved roots. The activity of the antioxidative enzymes SOD, peroxidase and APX in potassium deprivation significantly increased, whereas CAT and DHAR activity was significantly depressed in the potassium starvation treatment compared to controls. GR did not show significant differences between control and potassium starvation treatments. Based on these results, we put forward the hypothesis that antioxidant molecule accumulations probably scavenge H(2)O(2) and might be regenerated by the ASC-glutathione cycle enzymes, such as DHAR and GR.
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Affiliation(s)
- M Hernandez
- Department of Stress Biology and Plant Pathology, CEBAS-CSIC, Campus de Espinardo, 30100 Espinardo-Murcia, Spain
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278
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Waqas M, Khan AL, Kamran M, Hamayun M, Kang SM, Kim YH, Lee IJ. Endophytic fungi produce gibberellins and indoleacetic acid and promotes host-plant growth during stress. Molecules 2012; 17:10754-73. [PMID: 22960869 PMCID: PMC6268353 DOI: 10.3390/molecules170910754] [Citation(s) in RCA: 225] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 08/17/2012] [Accepted: 09/03/2012] [Indexed: 02/06/2023] Open
Abstract
We isolated and examined two endophytic fungi for their potential to secrete phytohormones viz. gibberellins (GAs) and indoleacetic acid (IAA) and mitigate abiotic stresses like salinity and drought. The endophytic fungi Phoma glomerata LWL2 and Penicillium sp. LWL3 significantly promoted the shoot and allied growth attributes of GAs-deficient dwarf mutant Waito-C and Dongjin-beyo rice. Analysis of the pure cultures of these endophytic fungi showed biologically active GAs (GA1, GA3, GA4 and GA7) in various quantities. The cultures of P. glomerata and Penicillium sp. also contained IAA. The culture application and endophytic-association with host-cucumber plants significantly increased the plant biomass and related growth parameters under sodium chloride and polyethylene glycol induced salinity and drought stress as compared to control plants. The endophytic symbiosis resulted in significantly higher assimilation of essential nutrients like potassium, calcium and magnesium as compared to control plants during salinity stress. Endophytic-association reduced the sodium toxicity and promoted the host-benefit ratio in cucumber plants as compared to non-inoculated control plants. The symbiotic-association mitigated stress by compromising the activities of reduced glutathione, catalase, peroxidase and polyphenol oxidase. Under stress conditions, the endophyte-infection significantly modulated stress through down-regulated abscisic acid, altered jasmonic acid, and elevated salicylic acid contents as compared to control. In conclusion, the two endophytes significantly reprogrammed the growth of host plants during stress conditions.
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Affiliation(s)
- Muhammad Waqas
- School of Applied Biosciences, College of Agriculture and Life Sciences, Kyungpook National University, Daegu 702-701, Korea; (M.W.); (A.L.K.); (M.K.); (S.-M.K.); (Y.-H.K.)
- Department of Agriculture Extension, Government of Khyber Pakhtunkhwa, Bunir 19290, Pakistan
| | - Abdul Latif Khan
- School of Applied Biosciences, College of Agriculture and Life Sciences, Kyungpook National University, Daegu 702-701, Korea; (M.W.); (A.L.K.); (M.K.); (S.-M.K.); (Y.-H.K.)
- Department of Botany, Kohat University of Science and Technology, Kohat 26000, Pakistan
| | - Muhammad Kamran
- School of Applied Biosciences, College of Agriculture and Life Sciences, Kyungpook National University, Daegu 702-701, Korea; (M.W.); (A.L.K.); (M.K.); (S.-M.K.); (Y.-H.K.)
| | - Muhammad Hamayun
- Department of Botany, Abdul Wali Khan University, Mardan 23300, Pakistan;
| | - Sang-Mo Kang
- School of Applied Biosciences, College of Agriculture and Life Sciences, Kyungpook National University, Daegu 702-701, Korea; (M.W.); (A.L.K.); (M.K.); (S.-M.K.); (Y.-H.K.)
| | - Yoon-Ha Kim
- School of Applied Biosciences, College of Agriculture and Life Sciences, Kyungpook National University, Daegu 702-701, Korea; (M.W.); (A.L.K.); (M.K.); (S.-M.K.); (Y.-H.K.)
| | - In-Jung Lee
- School of Applied Biosciences, College of Agriculture and Life Sciences, Kyungpook National University, Daegu 702-701, Korea; (M.W.); (A.L.K.); (M.K.); (S.-M.K.); (Y.-H.K.)
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279
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Xia X, Zhang HM, Andriunas FA, Offler CE, Patrick JW. Extracellular hydrogen peroxide, produced through a respiratory burst oxidase/superoxide dismutase pathway, directs ingrowth wall formation in epidermal transfer cells of Vicia faba cotyledons. PLANT SIGNALING & BEHAVIOR 2012; 7:1125-8. [PMID: 22899058 PMCID: PMC3489643 DOI: 10.4161/psb.21320] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The intricate, and often polarized, ingrowth walls of transfer cells (TCs) amplify their plasma membrane surface areas to confer a transport function of supporting high rates of nutrient exchange across apo-/symplasmic interfaces. The TC ingrowth wall comprises a uniform wall layer on which wall ingrowths are deposited. Signals and signal cascades inducing trans-differentiation events leading to formation of TC ingrowth walls are poorly understood. Vicia faba cotyledons offer a robust experimental model to examine TC induction as, when placed into culture, their adaxial epidermal cells rapidly (h) and synchronously form polarized ingrowth walls accessible for experimental observations. Using this model, we recently reported findings consistent with extracellular hydrogen peroxide, produced through a respiratory burst oxidase homolog/superoxide dismutase pathway, initiating cell wall biosynthetic activity and providing directional information guiding deposition of the polarized uniform wall. Our conclusions rested on observations derived from pharmacological manipulations of hydrogen peroxide production and correlative gene expression data sets. A series of additional studies were undertaken, the results of which verify that extracellular hydrogen peroxide contributes to regulating ingrowth wall formation and is generated by a respiratory burst oxidase homolog/superoxide dismutase pathway.
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280
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Jang JY, Rhee JY, Chung GC, Kang H. Aquaporin as a membrane transporter of hydrogen peroxide in plant response to stresses. PLANT SIGNALING & BEHAVIOR 2012; 7:1180-1. [PMID: 22899075 PMCID: PMC3489655 DOI: 10.4161/psb.21178] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Hydrogen peroxide (H 2O 2) is a reactive oxygen species that signals between cells, and H 2O 2 signaling is essential for diverse cellular processes, including stress response, defense against pathogens, and the regulation of programmed cell death in plants. Although plasma membrane intrinsic proteins (PIPs) have been known to transport H 2O 2 across cell membranes, the permeability of each family member of PIPs toward H 2O 2 has not yet been determined in most plant species. In a recent study, we showed that certain isoforms of Arabidopsis thaliana AtPIPs, including AtPIP2;2, AtPIP2;4, AtPIP2;5, and AtPIP2;7, are permeable for H 2O 2 in yeast cells. Since the expression of PIPs is differently modulated in Arabidopsis by abiotic stress or H 2O 2 treatment, it is important to investigate the integrated regulation of aquaporin expression and their physiological significance in H 2O 2 transport and plant response to diverse abiotic stresses.
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281
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Mittal D, Madhyastha DA, Grover A. Genome-wide transcriptional profiles during temperature and oxidative stress reveal coordinated expression patterns and overlapping regulons in rice. PLoS One 2012; 7:e40899. [PMID: 22815860 PMCID: PMC3397947 DOI: 10.1371/journal.pone.0040899] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2012] [Accepted: 06/14/2012] [Indexed: 11/19/2022] Open
Abstract
Genome wide transcriptional changes by cold stress, heat stress and oxidative stress in rice seedlings were analyzed. Heat stress resulted in predominant changes in transcripts of heat shock protein and heat shock transcription factor genes, as well as genes associated with synthesis of scavengers of reactive oxygen species and genes that control the level of sugars, metabolites and auxins. Cold stress treatment caused differential expression of transcripts of various transcription factors including desiccation response element binding proteins and different kinases. Transcripts of genes that are part of calcium signaling, reactive oxygen scavenging and diverse metabolic reactions were differentially expressed during cold stress. Oxidative stress induced by hydrogen peroxide treatment, resulted in significant up-regulation in transcript levels of genes related to redox homeostasis and down-regulation of transporter proteins. ROS homeostasis appeared to play central role in response to temperature extremes. The key transcription factors that may underlie the concerted transcriptional changes of specific components in various signal transduction networks involved are highlighted. Co-ordinated expression pattern and promoter architectures based analysis (promoter models and overrepresented transcription factor binding sites) suggested potential regulons involved in stress responses. A considerable overlap was noted at the level of transcription as well as in regulatory modules of differentially expressed genes.
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Affiliation(s)
- Dheeraj Mittal
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
| | | | - Anil Grover
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
- * E-mail:
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282
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Gondim FA, Gomes-Filho E, Costa JH, Mendes Alencar NL, Prisco JT. Catalase plays a key role in salt stress acclimation induced by hydrogen peroxide pretreatment in maize. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2012; 56:62-71. [PMID: 22609456 DOI: 10.1016/j.plaphy.2012.04.012] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Accepted: 04/19/2012] [Indexed: 05/22/2023]
Abstract
Pretreatment in plants is recognized as a valuable strategy to stimulate plant defenses, leading to better plant development. This study evaluated the effects of H₂O₂ leaf spraying pretreatment on plant growth and investigated the antioxidative mechanisms involved in the response of maize plants to salt stress. It was found that salinity reduced maize seedling growth when compared to control conditions, and H₂O₂ foliar spraying was effective in minimizing this effect. Analysis of the antioxidative enzymes catalase (EC 1.11.1.6), guaiacol peroxidase (EC 1.11.1.7), ascorbate peroxidase (EC 1.11.1.1) and superoxide dismutase (EC 1.15.1.1) revealed that H₂O₂ spraying increased antioxidant enzyme activities. Catalase (CAT) was the most responsive of these enzymes to H₂O₂, with higher activity early (48 h) in the treatment, while guaiacol peroxidase (GPX) and ascorbate peroxidase (APX) were responsive only at later stages (240 h) of treatment. Increased CAT activity appears linked to gene expression regulation. Lower malondialdehyde levels were detected in plants with higher CAT activity, which may result from the protective function of this enzyme. Overall, we can conclude that pretreatment with H₂O₂ leaf spraying was able to reduce the deleterious effects of salinity on seedling growth and lipid peroxidation. These responses could be attributed to the ability of H₂O₂ to induce antioxidant defenses, especially CAT activity.
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Affiliation(s)
- Franklin Aragão Gondim
- Departamento de Bioquímica e Biologia Molecular and Instituto Nacional de Ciência e Tecnologia em Salinidade-INCTSal/CNPq, Universidade Federal do Ceará, Caixa Postal 6039, 60440-970 Fortaleza, Ceará, Brazil
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283
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Opdenakker K, Remans T, Vangronsveld J, Cuypers A. Mitogen-Activated Protein (MAP) kinases in plant metal stress: regulation and responses in comparison to other biotic and abiotic stresses. Int J Mol Sci 2012; 13:7828-7853. [PMID: 22837729 PMCID: PMC3397561 DOI: 10.3390/ijms13067828] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Revised: 06/16/2012] [Accepted: 06/18/2012] [Indexed: 11/29/2022] Open
Abstract
Exposure of plants to toxic concentrations of metals leads to disruption of the cellular redox status followed by an accumulation of reactive oxygen species (ROS). ROS, like hydrogen peroxide, can act as signaling molecules in the cell and induce signaling via mitogen-activated protein kinase (MAPK) cascades. MAPK cascades are evolutionary conserved signal transduction modules, able to convert extracellular signals to appropriate cellular responses. In this review, our current understanding about MAPK signaling in plant metal stress is discussed. However, this knowledge is scarce compared to research into the role of MAPK signaling in the case of other abiotic and biotic stresses. ROS production is a common response induced by different stresses and undiscovered analogies may exist with metal stress. Therefore, further attention is given to MAPK signaling in other biotic and abiotic stresses and its interplay with other signaling pathways to create a framework in which the involvement of MAPK signaling in metal stress may be studied.
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Affiliation(s)
- Kelly Opdenakker
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek, Belgium; E-Mails: (K.O.); (T.R.); (J.V.)
| | - Tony Remans
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek, Belgium; E-Mails: (K.O.); (T.R.); (J.V.)
| | - Jaco Vangronsveld
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek, Belgium; E-Mails: (K.O.); (T.R.); (J.V.)
| | - Ann Cuypers
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek, Belgium; E-Mails: (K.O.); (T.R.); (J.V.)
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284
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Oh Y, Baldwin IT, Gális I. NaJAZh regulates a subset of defense responses against herbivores and spontaneous leaf necrosis in Nicotiana attenuata plants. PLANT PHYSIOLOGY 2012; 159:769-88. [PMID: 22496510 PMCID: PMC3375940 DOI: 10.1104/pp.112.193771] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Accepted: 04/05/2012] [Indexed: 05/18/2023]
Abstract
The JASMONATE ZIM DOMAIN (JAZ) proteins function as negative regulators of jasmonic acid signaling in plants. We cloned 12 JAZ genes from native tobacco (Nicotiana attenuata), including nine novel JAZs in tobacco, and examined their expression in plants that had leaves elicited by wounding or simulated herbivory. Most JAZ genes showed strong expression in the elicited leaves, but NaJAZg was mainly expressed in roots. Another novel herbivory-elicited gene, NaJAZh, was analyzed in detail. RNA interference suppression of this gene in inverted-repeat (ir)JAZh plants deregulated a specific branch of jasmonic acid-dependent direct and indirect defenses: irJAZh plants showed greater trypsin protease inhibitor activity, 17-hydroxygeranyllinalool diterpene glycosides accumulation, and emission of volatile organic compounds from leaves. Silencing of NaJAZh also revealed a novel cross talk in JAZ-regulated secondary metabolism, as irJAZh plants had significantly reduced nicotine levels. In addition, irJAZh spontaneously developed leaf necrosis during the transition to flowering. Because the lesions closely correlated with the elevated expression of programmed cell death genes and the accumulations of salicylic acid and hydrogen peroxide in the leaves, we propose a novel role of the NaJAZh protein as a repressor of necrosis and/or programmed cell death during plant development.
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Affiliation(s)
- Youngjoo Oh
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Jena D–07745, Germany
| | - Ian T. Baldwin
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Jena D–07745, Germany
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285
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He H, Su J, Shu S, Zhang Y, Ao Y, Liu B, Feng D, Wang J, Wang H. Two homologous putative protein tyrosine phosphatases, OsPFA-DSP2 and AtPFA-DSP4, negatively regulate the pathogen response in transgenic plants. PLoS One 2012; 7:e34995. [PMID: 22514699 PMCID: PMC3325911 DOI: 10.1371/journal.pone.0034995] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Accepted: 03/08/2012] [Indexed: 12/31/2022] Open
Abstract
Protein phosphatases, together with protein kinases, regulate protein phosphorylation and dephosphorylation, and play critical roles in plant growth and biotic stress responses. However, little is known about the biological functions of plant protein tyrosine dual-specificity phosphatase (PFA-DSP) in biotic stresses. Here, we found that OsPFA-DSP2 was mainly expressed in calli, seedlings, roots, and young panicles, and localized in cytoplasm and nucleus. Ectopic overexpression of OsPFA-DSP2 in rice increased sensitivity to Magnaporthe grisea (M. grisea Z1 strain), inhibited the accumulation of hydrogen peroxide (H2O2) and suppressed the expression of pathogenesis-related (PR) genes after fungal infection. Interestingly, transgenic Arabidopsis plants overexpressing AtPFA-DSP4, which is homologous to OsPFA-DSP2, also exhibited sensitivity to Pseudomonas syringae pv. tomato DC3000 (Pst DC3000), reduced accumulation of H2O2 and decreased photosynthesic capacity after infection compared with Col-0. These results indicate that OsPFA-DSP2 and AtPFA-DSP4 act as negative regulators of the pathogen response in transgenic plants.
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Affiliation(s)
- Hanjie He
- Key Laboratory of Gene Engineering of Ministry of Education, State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Jianbin Su
- Key Laboratory of Gene Engineering of Ministry of Education, State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Shengying Shu
- Key Laboratory of Gene Engineering of Ministry of Education, State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Yang Zhang
- Key Laboratory of Gene Engineering of Ministry of Education, State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Ying Ao
- Key Laboratory of Gene Engineering of Ministry of Education, State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Bing Liu
- Key Laboratory of Gene Engineering of Ministry of Education, State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Dongru Feng
- Key Laboratory of Gene Engineering of Ministry of Education, State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Jinfa Wang
- Key Laboratory of Gene Engineering of Ministry of Education, State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Hongbin Wang
- Key Laboratory of Gene Engineering of Ministry of Education, State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, People's Republic of China
- * E-mail:
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286
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Matsumoto H, Motoda H. Aluminum toxicity recovery processes in root apices. Possible association with oxidative stress. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2012; 185-186:1-8. [PMID: 22325861 DOI: 10.1016/j.plantsci.2011.07.019] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Revised: 07/22/2011] [Accepted: 07/29/2011] [Indexed: 05/31/2023]
Abstract
Al inhibits root apex elongation with concomitant morphological injuries such as ruptures punctuated by the regions stained with Evans blue. The recovery can be investigated by transfer of Al-injured roots to a solution lacking Al. In the Al-injured root apex, superoxide anion, H(2)O(2), Al, and lignin accumulate. During the recovery process, the central cylinder elongates leaving the region stained with Evans blue without marked disappearance. The obvious function of the region is not clear but may trigger the elongation of central cylinder during the recovery process. Thus the function of the region stained with Evans blue might be derived from the programmed cell-like idea. Oxidative stress concerns events induced under Al toxicity and the recovery process. The superoxide anion is primarily formed by plasma membrane-associated NADPH oxidase and is dismuted to H(2)O(2) and O(2) by superoxide dismutase. H(2)O(2) provides the electrons for the polymerization of phenolics to lignin, which causes the stiffening of the cell wall. The distortion of the cell wall caused by lignin may induce the breaking and tearing of cells, which results in the formation of ruptures at the rhizodermis and outer cortex layers. The production of superoxide anion, H(2)O(2), and lignin was reduced during the recovery process and thereby the elongation of the central cylinder may be induced.
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Affiliation(s)
- Hideaki Matsumoto
- Research Institute of Health and Welfare, Kibi International University, Iga, Takahashi 716-8508, Japan.
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287
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A new currency for mutualism? Fungal endophytes alter antioxidant activity in hosts responding to drought. FUNGAL DIVERS 2012. [DOI: 10.1007/s13225-012-0156-y] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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288
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Wang Z, Li D, Qin H, Li Y. An integrated method for removal of harmful cyanobacterial blooms in eutrophic lakes. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2012; 160:34-41. [PMID: 22035923 DOI: 10.1016/j.envpol.2011.09.003] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 08/31/2011] [Accepted: 09/01/2011] [Indexed: 05/31/2023]
Abstract
As the eutrophication of lakes becomes an increasingly widespread phenomenon, cyanobacterial blooms are occurring in many countries. Although some research has been reported, there is currently no good method for bloom removal. We propose here a new two-step integrated approach to resolve this problem. The first step is the inactivation of the cyanobacteria via the addition of H(2)O(2). We found 60 mg/L was the lowest effective dose for a cyanobacterial concentration corresponding to 100 μg/L chlorophyll-a. The second step is the flocculation and sedimentation of the inactivated cyanobacteria. We found the addition of lake sediment clay (2 g/L) plus polymeric ferric sulfate (20 mg/L) effectively deposited them on the lake bottom. Since algaecides and flocculants had been used separately in previous reports, we innovatively combined these two types of reagents to remove blooms from the lake surface and to improve the dissolved oxygen content of lake sediments.
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Affiliation(s)
- Zhicong Wang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China
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289
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Hemmerlin A, Harwood JL, Bach TJ. A raison d'être for two distinct pathways in the early steps of plant isoprenoid biosynthesis? Prog Lipid Res 2011; 51:95-148. [PMID: 22197147 DOI: 10.1016/j.plipres.2011.12.001] [Citation(s) in RCA: 208] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 11/28/2011] [Accepted: 12/05/2011] [Indexed: 12/12/2022]
Abstract
When compared to other organisms, plants are atypical with respect to isoprenoid biosynthesis: they utilize two distinct and separately compartmentalized pathways to build up isoprene units. The co-existence of these pathways in the cytosol and in plastids might permit the synthesis of many vital compounds, being essential for a sessile organism. While substrate exchange across membranes has been shown for a variety of plant species, lack of complementation of strong phenotypes, resulting from inactivation of either the cytosolic pathway (growth and development defects) or the plastidial pathway (pigment bleaching), seems to be surprising at first sight. Hundreds of isoprenoids have been analyzed to determine their biosynthetic origins. It can be concluded that in angiosperms, under standard growth conditions, C₂₀-phytyl moieties, C₃₀-triterpenes and C₄₀-carotenoids are made nearly exclusively within compartmentalized pathways, while mixed origins are widespread for other types of isoprenoid-derived molecules. It seems likely that this coexistence is essential for the interaction of plants with their environment. A major purpose of this review is to summarize such observations, especially within an ecological and functional context and with some emphasis on regulation. This latter aspect still requires more work and present conclusions are preliminary, although some general features seem to exist.
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Affiliation(s)
- Andréa Hemmerlin
- Institut de Biologie Moléculaire des Plantes du Centre National de la Recherche Scientifique, IBMP-CNRS-UPR2357, Université de Strasbourg, 28 Rue Goethe, F-67083 Strasbourg Cedex, France.
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290
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Hasanuzzaman M, Hossain MA, Fujita M. Selenium-induced up-regulation of the antioxidant defense and methylglyoxal detoxification system reduces salinity-induced damage in rapeseed seedlings. Biol Trace Elem Res 2011; 143:1704-21. [PMID: 21264525 DOI: 10.1007/s12011-011-8958-4] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2010] [Accepted: 01/05/2011] [Indexed: 11/28/2022]
Abstract
The present study investigates the regulatory role of exogenous selenium (Se) in the antioxidant defense and methylglyoxal (MG) detoxification systems in rapeseed seedlings exposed to salt stress. Twelve-day-old seedlings, grown in Petri dishes, were supplemented with selenium (25 μM Na(2)SeO(4)) and salt (100 and 200 mM NaCl) separately and in combination, and further grown for 48 h. The ascorbate (AsA) content of the seedlings decreased significantly with increased salt stress. The amount of reduced glutathione (GSH) and glutathione disulfide (GSSG) increased with an increase in the level of salt stress, while the GSH/GSSG ratio decreased. In addition, the ascorbate peroxidase (APX) and glutathione S-transferase (GST) activity increased significantly with increased salt concentration (both at 100 and 200 mM NaCl), while glutathione peroxidase (GPX) activity increased only at moderate salt stress (100 mM NaCl). Glutathione reductase (GR) activity remained unchanged at 100 mM NaCl, while it was decreased under severe (200 mM NaCl) salt stress. Monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), catalase (CAT), glyoxalase I (Gly I), and glyoxalase II (Gly II) activities decreased upon the imposition of salt stress, whereas a sharp decrease of these activities was observed under severe salt stress (200 mM NaCl). Concomitant increases in the levels of H(2)O(2) and lipid peroxidation (MDA) were also measured. Exogenous Se treatment alone had little effect on the non-enzymatic and enzymatic components. However, further investigation revealed that Se treatment had a synergistic effect: in salt-stressed seedlings, it increased the AsA and GSH contents; GSH/GSSG ratio; and the activities of APX, MDHAR, DHAR, GR, GST, GPX, CAT, Gly I, and Gly II. As a result, addition of Se in salt-stressed seedlings led to a reduction in the levels of H(2)O(2) and MDA as compared to salt stress alone. These results suggest that the exogenous application of Se rendered the plants more tolerant to salt stress-induced oxidative damage by enhancing their antioxidant defense and MG detoxification systems.
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Affiliation(s)
- Mirza Hasanuzzaman
- Laboratory of Plant Stress Responses, Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, Miki-cho, Kita-gun, Kagawa, 761-0795, Japan.
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291
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Abstract
Responses of plants to water stress may be assigned as either injurious change or tolerance index. One of the primary and cardinal changes in response to drought stress is the generation of reactive oxygen species (ROS), which is being considered as the cause of cellular damage. However, recently a signaling role of such ROS in triggering the ROS scavenging system that may confer protection or tolerance against stress is emerging. Such scavenging system consists of antioxidant enzymes like SOD, catalase and peroxidases, and antioxidant compounds like ascorbate, reduced glutathione; a balance between ROS generation and scavenging ultimately determines the oxidative load. As revealed in case of defence against pathogen, signaling via ROS is initiated by NADPH oxidase-catalyzed superoxide generation in the apoplastic space (cell wall) followed by conversion to hydrogen peroxide by the activity of cell wall-localized SOD. Wall peroxidase may also play role in ROS generation for signaling. Hydrogen peroxide may use Ca2+ and MAPK pathway as downstream signaling cascade. Plant hormones associated with stress responses like ABA and ethylene play their role possibly via a cross talk with ROS towards stress tolerance, thus projecting a dual role of ROS under drought stress.
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Affiliation(s)
- Rup Kumar Kar
- Department of Botany, Visva-Bharati, Santiniketan, India.
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292
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Dias CV, Mendes JS, dos Santos AC, Pirovani CP, da Silva Gesteira A, Micheli F, Gramacho KP, Hammerstone J, Mazzafera P, de Mattos Cascardo JC. Hydrogen peroxide formation in cacao tissues infected by the hemibiotrophic fungus Moniliophthora perniciosa. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2011; 49:917-922. [PMID: 21641227 DOI: 10.1016/j.plaphy.2011.05.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Accepted: 05/10/2011] [Indexed: 05/30/2023]
Abstract
In plant-pathogen interaction, the hydrogen peroxide (H₂O₂) may play a dual role: its accumulation inhibits the growth of biotrophic pathogens, while it could help the infection/colonization process of plant by necrotrophic pathogens. One of the possible pathways of H₂O production involves oxalic acid (Oxa) degradation by apoplastic oxalate oxidase. Here, we analyzed the production of H₂O₂, the presence of calcium oxalate (CaOx) crystals and the content of Oxa and ascorbic acid (Asa)--the main precursor of Oxa in plants--in susceptible and resistant cacao (Theobroma cacao L.) infected by the hemibiotrophic fungus Moniliophthora perniciosa. We also quantified the transcript level of ascorbate peroxidase (Apx), germin-like oxalate oxidase (Glp) and dehydroascorbate reductase (Dhar) by RT-qPCR. We report that the CaOx crystal amount and the H₂O₂ levels in the two varieties present distinct temporal and genotype-dependent patterns. Susceptible variety accumulated more CaOx crystals than the resistant one, and the dissolution of these crystals occurred in the early infection steps and in the final stage of the disease in the resistant and the susceptible variety, respectively. High expression of the Glp and accumulation of Oxa were observed in the resistant variety. The content of Asa increased in the inoculated susceptible variety, but remained constant in the resistant one. The susceptible variety presented reduced Dhar expression. The role of H₂O₂ and its formation from Oxa via Apx and Glp in resistant and susceptible variety infected by M. perniciosa were discussed.
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Affiliation(s)
- Cristiano Villela Dias
- UESC, DCB, Centro de Biotecnologia e Genética, Rodovia Ilhéus-Itabuna Km 16, 45662-900 Ilhéus-BA, Brazil
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293
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Liu C, Zhao L, Yu G. The dominant glutamic acid metabolic flux to produce γ-amino butyric acid over proline in Nicotiana tabacum leaves under water stress relates to its significant role in antioxidant activity. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2011; 53:608-18. [PMID: 21564543 DOI: 10.1111/j.1744-7909.2011.01049.x] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
γ-Amino butyric acid (GABA) and proline play a crucial role in protecting plants during various environmental stresses. Their synthesis is from the common precursor glutamic acid, which is catalyzed by glutamate decarboxylase and Δ(1) -pyrroline-5-carboxylate synthetase respectively. However, the dominant pathway under water stress has not yet been established. To explore this, excised tobacco leaves were used to simulate a water-stress condition. The results showed GABA content was much higher than that of proline in leaves under water-deficit and non-water-deficit conditions. Specifically, the amount of GABA significantly increased compared to proline under continuous water loss for 16 h, indicating that GABA biosynthesis is the dominant pathway from glutamic acid metabolism under these conditions. Quantitative reverse transcription polymerase chain reaction and protein Western gel-blot analysis further confirmed this. To explore the function of GABA accumulation, a system producing superoxide anion (O(2) (-) ), peroxide hydrogen (H(2) O(2) ), and singlet oxygen ((1) O(2) ) was employed to investigate the scavenging role on free-radical production. The results demonstrated that the scavenging ability of GABA for O(2) (-) , H(2) O(2) , and (1) O(2) was significantly higher than that of proline. This indicated that GABA acts as an effective osmolyte to reduce the production of reactive oxygen species under water stress.
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Affiliation(s)
- Cuili Liu
- Key Laboratory for Biotechnology of the State Ethnic Affairs Commission, College of Life Sciences, South-Central University for Nationalities, Wuhan, China
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294
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DONG Y, LIU LQ, GUAN JF. Effects of 1-Methylcyclopropene on NO Content, NOS Activity, and H2O2 Content in Postharvest Suli Pears. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/s1671-2927(11)60064-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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295
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Xie YJ, Xu S, Han B, Wu MZ, Yuan XX, Han Y, Gu Q, Xu DK, Yang Q, Shen WB. Evidence of Arabidopsis salt acclimation induced by up-regulation of HY1 and the regulatory role of RbohD-derived reactive oxygen species synthesis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2011; 66:280-92. [PMID: 21205037 DOI: 10.1111/j.1365-313x.2011.04488.x] [Citation(s) in RCA: 172] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
In Arabidopsis thaliana, a family of four genes (HY1, HO2, HO3 and HO4) encode haem oxygenase (HO), and play a major role in phytochrome chromophore biosynthesis. To characterize the contribution of the various haem oxygenase isoforms involved in salt acclimation, the effects of NaCl on seed germination and primary root growth in Arabidopsis wild-type and four HO mutants (hy1-100, ho2, ho3 and ho4) were compared. Among the four HO mutants, hy1-100 displayed maximal sensitivity to salinity and showed no acclimation response, whereas plants over-expressing HY1 (35S:HY1) exhibited tolerance characteristics. Mild salt stress stimulated biphasic increases in RbohD transcripts and production of reactive oxygen species (ROS) (peaks I and II) in wild-type. ROS peak I-mediated HY1 induction and subsequent salt acclimation were observed, but only ROS peak I was seen in the hy1-100 mutant. A subsequent test confirmed the causal relationship of salt acclimation with haemin-induced HY1 expression and RbohD-derived ROS peak II formation. In atrbohD mutants, haemin pre-treatment resulted in induction of HY1 expression, but no similar response was seen in hy1-100, and no ROS peak II or subsequent salt acclimatory responses were observed. Together, the above findings suggest that HY1 plays an important role in salt acclimation signalling, and requires participation of RbohD-derived ROS peak II.
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Affiliation(s)
- Yan-Jie Xie
- College of Life Sciences, Cooperative Demonstration Laboratory of Centrifuge Technique, Nanjing Agricultural University, and Beckman Coulter Ltd, Nanjing Agricultural University, Nanjing 210095, China
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296
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Enrique R, Siciliano F, Favaro MA, Gerhardt N, Roeschlin R, Rigano L, Sendin L, Castagnaro A, Vojnov A, Marano MR. Novel demonstration of RNAi in citrus reveals importance of citrus callose synthase in defence against Xanthomonas citri subsp. citri. PLANT BIOTECHNOLOGY JOURNAL 2011; 9:394-407. [PMID: 20809929 DOI: 10.1111/j.1467-7652.2010.00555.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Citrus is an economically important fruit crop that is severely afflicted by citrus canker, a disease caused by the bacterial phytopathogen, Xanthomonas citri subsp. citri (Xcc). GenBank houses a large collection of Expressed Sequence Tags (ESTs) enriched with transcripts generated during the defence response against this pathogen; however, there are currently no strategies in citrus to assess the function of candidate genes. This has greatly limited research as defence signalling genes are often involved in multiple pathways. In this study, we demonstrate the efficacy of RNA interference (RNAi) as a functional genomics tool to assess the function of candidate genes involved in the defence response of Citrus limon against the citrus canker pathogen. Double-stranded RNA expression vectors, encoding hairpin RNAs for citrus host genes, were delivered to lemon leaves by transient infiltration with transformed Agrobacterium. As proof of principle, we have established silencing of citrus phytoene desaturase (PDS) and callose synthase (CalS1) genes. Phenotypic and molecular analyses showed that silencing vectors were functional not only in lemon plants but also in other species of the Rutaceae family. Using silencing of CalS1, we have demonstrated that plant cell wall-associated defence is the principal initial barrier against Xanthomonas infection in citrus plants. Additionally, we present here results that suggest that H₂O₂ accumulation, which is suppressed by xanthan from Xcc during pathogenesis, contributes to inhibition of xanthan-deficient Xcc mutant growth either in wild-type or CalS1-silenced plants. With this work, we have demonstrated that high-throughput reverse genetic analysis is feasible in citrus.
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Affiliation(s)
- Ramón Enrique
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Área Virología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha, Rosario, Argentina
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297
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Hurley DJ, Hurley KAE, Galland KL, Baker B, Berghaus LJ, Moore JN, Majerle RSK. Evaluation of the ability of aqueous black walnut extracts to induce the production of reactive oxygen species. Am J Vet Res 2011; 72:308-17. [DOI: 10.2460/ajvr.72.3.308] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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298
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Kundu S, Chakraborty D, Pal A. Proteomic analysis of salicylic acid induced resistance to Mungbean Yellow Mosaic India Virus in Vigna mungo. J Proteomics 2011; 74:337-49. [DOI: 10.1016/j.jprot.2010.11.012] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Revised: 11/23/2010] [Accepted: 11/26/2010] [Indexed: 11/26/2022]
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299
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Lachaud C, Da Silva D, Amelot N, Béziat C, Brière C, Cotelle V, Graziana A, Grat S, Mazars C, Thuleau P. Dihydrosphingosine-induced programmed cell death in tobacco BY-2 cells is independent of H₂O₂ production. MOLECULAR PLANT 2011; 4:310-8. [PMID: 21199880 DOI: 10.1093/mp/ssq077] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Sphinganine or dihydrosphingosine (d18:0, DHS), one of the most abundant free sphingoid Long Chain Base (LCB) in plants, has been recently shown to induce both cytosolic and nuclear calcium transient increases and a correlated Programmed Cell Death (PCD) in tobacco BY-2 cells. In this study, in order to get deeper insight into the LCB signaling pathway leading to cell death, the putative role of Reactive Oxygen Species (ROS) has been investigated. We show that DHS triggers a rapid dose-dependent production of H₂O₂ that is blocked by diphenyleniodonium (DPI), indicating the involvement of NADPH oxidase(s) in the process. In addition, while DPI does not block DHS-induced calcium increases, the ROS production is inhibited by the broad spectrum calcium channel blocker lanthanum (La³+). Therefore, ROS production occurs downstream of DHS-induced Ca²+ transients. Interestingly, DHS activates expression of defense-related genes that is inhibited by both La³+ and DPI. Since DPI does not prevent DHS-induced cell death, these results strongly indicate that DHS-induced H₂O₂ production is not implicated in PCD mechanisms but rather would be associated to basal cell defense mechanisms.
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Affiliation(s)
- Christophe Lachaud
- UPS, UMR 5546, Surfaces Cellulaires et Signalisation chez les Végétaux, Université de Toulouse, BP 42617, F-31326 Castanet-Tolosan, France
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300
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Hove RM, Bhave M. Plant aquaporins with non-aqua functions: deciphering the signature sequences. PLANT MOLECULAR BIOLOGY 2011; 75:413-30. [PMID: 21308399 DOI: 10.1007/s11103-011-9737-5] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2010] [Accepted: 01/12/2011] [Indexed: 05/18/2023]
Abstract
Research in recent years on plant Major Intrinsic Proteins (MIPs), commonly referred to as 'aquaporins', has seen a vast expansion in the substrates found to be transported via these membrane channels. The diversity in sizes, chemical nature and physiological significance of these substrates has meant a need to critically analyse the possible structural and biochemical properties of MIPs that transport these, in order to understand their roles. In this work we have undertaken a comprehensive analysis of all plant MIPs, coming from different families, that have been proven to transport ammonia, boron, carbon dioxide, hydrogen peroxide, silicon and urea. The sequences were analysed for all primary selectivity-related motifs (NPA motifs, ar/R filter, P1-P5 residues). In addition, the putative regulatory phosphorylation and glycosylation sites and mechanistic regulators such as loop lengths have been analysed. Further, nine specificity-determining positions (SDPs) were predicted for each group. The results show the ar/R filter residues, P2-P4 positions and some of the SDPs are characteristic for certain groups, and O-glycosylation sites are unique to a subgroup while N-glycosylation was characteristic of the other MIPs. Certain residues, especially in loop C, and structural parameters such as loop lengths also contribute to the uniqueness of groups. The comprehensive analysis makes significant inroads into appraising the intriguing diversity of plant MIPs and their roles in fundamental life processes, and provides tools for plant selections, protein engineering and transgenics.
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Affiliation(s)
- Runyararo Memory Hove
- Environment and Biotechnology Centre, Faculty of Life and Social Sciences, Swinburne University of Technology, P O Box 218, Hawthorn, VIC, 3122, Australia
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