Proteomic and molecular analyses to understand the promotive effect of safranal on soybean growth under salt stress

Safranal is a free radical scavenger and useful as an antioxidant molecule; however, its promotive role in soybean is not explored. Salt stress decreased soybean growth and safranal improved it even if under salt stress. To study the positive mechanism of safranal on soybean growth, a proteomic approach was used. According to functional categorization, oppositely changed proteins were further confirmed using biochemical techniques. Actin and calcium-dependent protein kinase decreased in soybean root and hypocotyl, respectively, under salt stress and increased with safranal application. Xyloglucan endotransglucosylase/ hydrolase increased in soybean root under salt stress but decreased with safranal application. Peroxidase increased under salt stress and further enhanced by safranal application in soybean root. Actin, RuvB-like helicase, and protein kinase domain-containing protein were upregulated under salt stress and further enhanced by safranal application under salt stress. Dynamin GTPase was downregulated under salt stress but recovered with safranal application under salt stress. Glutathione peroxidase and PfkB domain-containing protein were upregulated by safranal application under salt stress in soybean root. These results suggest that safranal improves soybean growth through the regulation of cell wall and nuclear proteins along with reactive‑oxygen species scavenging system. Furthermore, it might promote salt-stress tolerance through the regulation of membrane proteins involved in endocytosis and post-Golgi trafficking. SIGNIFICANCE: To study the positive mechanism of safranal on soybean growth, a proteomic approach was used. According to functional categorization, oppositely changed proteins were further confirmed using biochemical techniques. Actin and calcium-dependent protein kinase decreased in soybean root and hypocotyl, respectively, under salt stress and increased with safranal application. Xyloglucan endotransglucosylase/ hydrolase increased in soybean root under salt stress but decreased with safranal application. Peroxidase increased under salt stress and further enhanced by safranal application in soybean root. Actin, RuvB-like helicase, and protein kinase domain-containing protein were upregulated under salt stress and further enhanced by safranal application under salt stress. Dynamin GTPase was downregulated under salt stress but recovered with safranal application under salt stress. Glutathione peroxidase and PfkB domain-containing protein were upregulated by safranal application under salt stress in soybean root. These results suggest that safranal improves soybean growth through the regulation of cell wall and nuclear proteins along with reactive‑oxygen species scavenging system. Furthermore, it might promote salt-stress tolerance through the regulation of membrane proteins involved in endocytosis and post-Golgi trafficking.

Quantitative Top-Down Proteomics in Complex Samples Using Protein-Level Tandem Mass Tag Labeling

Labeling approaches using isobaric chemical tags (e.g., isobaric tagging for relative and absolute quantification, iTRAQ and tandem mass tag, TMT) have been widely applied for the quantification of peptides and proteins in bottom-up MS. However, until recently, successful applications of these approaches to top-down proteomics have been limited because proteins tend to precipitate and "crash" out of solution during TMT labeling of complex samples making the quantification of such samples difficult. In this study, we report a top-down TMT MS platform for confidently identifying and quantifying low molecular weight intact proteoforms in complex biological samples. To reduce the sample complexity and remove large proteins from complex samples, we developed a filter-SEC technique that combines a molecular weight cutoff filtration step with high-performance size exclusion chromatography (SEC) separation. No protein precipitation was observed in filtered samples under the intact protein-level TMT labeling conditions. The proposed top-down TMT MS platform enables high-throughput analysis of intact proteoforms, allowing for the identification and quantification of hundreds of intact proteoforms from Escherichia coli cell lysates. To our knowledge, this represents the first high-throughput TMT labeling-based, quantitative, top-down MS analysis suitable for complex biological samples.

Colorimetric determination of F-, Br- and I- ions by Ehrlich's bio-reagent oxidation over enzyme mimic like gold nanoparticles: Peroxidase-like activity and multivariate optimization

Citrate and polyvinyl alcohol capped gold nanoparticles (PVA-GNPs) were synthesized via chemical reduction technique and fully characterized by DLS, SEM, EDS, XRD, UV-Vis and FT-IR analysis. A simple and practical colorimetric sensor based on red-ox reaction of p-dimethylaminobenzaldehyde (DABA) as ehrlich's bio-reagent and Au(III) with H₂O₂ on PVA-GNPs mimic catalyst with enzyme-like activity, has been fabricated for determination of F^-, Br^- and I^- halide anions. Prepared PVA-GNPs, can simultaneously catalyze the disintegration of H₂O₂, that used to reduce Au(III) ions into co-doped Au-NPs and oxidation of p-dimethylaminobenzaldehyde ehrlich's bio-reagent while in the presence of halide ions Au-X complex can be formed and improved sensor selectivity. Halide ions (F^-, Br^- and I^-) effectively diminishes the catalytic activity of GNPs to disintegrate oxygenated water by the interaction among Au⁺ and Au⁰ and suppressing oxidation of p-dimethylaminobenzaldehyde ehrlich's bio-reagent. In this system which contains PVA-GNPs, H₂O₂, p-dimethylaminobenzaldehyde ehrlich's bio-reagent, and Au(III), increasing the halide ions (F^-, Br^- and I^-) concentration show color changes from deep green to red. In view of this rule, in this work, a novel colorimetric technique for sensitive determination of F^-, Br^- and I^- was developed. This method has the detection limits of 2.60 × 10^-6 M, 6.64 × 10^-8 M and 9.93 × 10^-9 M and linear ranges between 1.98 × 10^-5-1.22 × 10^-3 M, 1.99 × 10^-6-2.0 × 10^-4 M and 1.07 × 10^-7- 2.86 × 10^-5 M for F^-, Br^- and I^-, respectively. Assays are highly selective over other ions. They effectively applied to detection of halide ions in real water samples.

Dissipation and the effects of thidiazuron on antioxidant enzyme activity and malondialdehyde content in strawberry

BACKGROUND

Increasing numbers of fruit swelling agents have been used to improve the fruit rate and production yield of strawberries in recent years. The abuse of fruit swelling agents could lead to an increase in the deformation rate and abnormal coloration of strawberry and a decrease in quality at harvest. Therefore, understanding the harmful effects of fruit swelling agents on strawberry will provide guidance for their reasonable use.

RESULTS

The residual determination method for measuring thidiazuron (TDZ) in strawberry was developed and validated by liquid chromatography and tandem mass spectrometry (LC-MS/MS). The recoveries of TDZ in strawberry were 97.9-108.5% with relative standard deviations of 0.9% to 5.3%. The dissipation rates of TDZ were different in strawberries cultivated under field and indoor conditions due to the differences in temperature and humidity. The ascorbic acid content increased when TDZ was applied at 2 mg kg^-1 . The SOD (superoxide dismutase), POD (peroxidase) and CAT (catalase) activities of strawberry tended to decrease and subsequently increase following the application of TDZ, and the opposite changes occurred on the malondialdehyde (MDA) content of TDZ-treated strawberry.

CONCLUSIONS

The analytical method for measuring TDZ in strawberry that was developed was suitable for dissipation studies on this compound. Antioxidant enzyme activities and the MDA content of strawberry were altered, and some reverse effects, such as membrane damage, were inhibited when TDZ was applied. The data obtained in this study might provide suggestions to reduce the adverse effects of TDZ on strawberry and may help to guide the safe and proper use of TDZ in strawberry. © 2019 Society of Chemical Industry.

Cyanobacterial Catalase Activity Prevents Oxidative Stress Induced by Pseudomonas fluorescens DUS1-27 from Inhibiting Brassica napus L. (canola) Growth

Plant growth-promoting bacteria (PGPB) inhabit the rhizosphere of plants and are capable of enhancing plant growth through a number of mechanisms. A strain of Pseudomonas fluorescens DUS1-27 was identified as a potential PGPB candidate based on its ability to increase the growth of Brassica napus L. (canola) over that of uninoculated control plants in a soil-based system. The same P. fluorescens isolate was found to reduce plant growth in a hydroponic growth system, with plants showing the symptoms of a microbe-associated molecular pattern (MAMP) response to the bacteria. The amperometric quantification of H2O2, fluorescence-based total peroxidase assays, and quantification of catalase gene expression levels using qRT-PCR revealed that oxidative stress reduced plant growth in the hydroponic system. The addition of the cyanobacterium Nostoc punctiforme (known to have high catalase activity levels) in the hydroponic system as a co-inoculant reduced oxidative stress (49.7% decrease in H2O2 concentrations) triggered by the addition of P. fluorescens DUS1-27, thereby enabling plants to grow larger than uninoculated control plants. These results show the advantage of inoculating with multiple bacteria to promote plant growth and, for the first time, demonstrate that N. punctiforme beneficially assists plants under oxidative stress through its catalase activity in planta.

Assessment of potentially toxic metal (PTM) pollution in mangrove habitats using biochemical markers: A case study on Avicennia officinalis L. in and around Sundarban, India

Spatial distribution of potentially toxic metals (PTMs) and their accumulation in mangrove Avicennia officinalis L. were studied along 8 locations in and around Sundarban mangrove wetland, India. Among 8 locations, S3 (Chemaguri) and S5 (Ghushighata) showed higher concentration of PTMs (Cd, Cr, Cu, Ni, Pb, Zn) characterized by higher enrichment factors (3.45-10.03), geo-accumulation indices (0.04-1.22), contamination factors (1.14-3.51) and pollution load indices (1.3-1.45) indicating progressive deterioration of estuarine quality and considerable ecotoxicological risk. Metal concentration in A. officinalis leaves showed significant correlation with sediment metals implying elevated level of bioaccumulation. Significant statistical correlation between photosynthetic pigments (Chlorophyll a, Chlorophyll b), antioxidant response (free radical scavenging and reducing ability) and stress enzymatic activity (Peroxidase, Catalase, Super-oxide dismutase) of A. officinalis with increasing metal concentration in the contaminated locations reflects active detoxification mechanism of the plant. The study indicates the potentiality of biomonitoring metal pollution using studied biochemical markers in mangrove habitats.

Enzymatic Profile of 'Willamette' Raspberry Leaf and Fruit Affected by Prohexadione-Ca and Young Canes Removal Treatments

The influence of growth regulator prohexadione-Ca (ProCa) concurrently with young canes removal on the modification of photosynthetic pigments content and antioxidant enzymes (peroxidase, POD; catalase, CAT; polyphenol oxidase, PPO; superoxide dismutase, SOD) activities in leaves and fruits of raspberry (Rubus idaeus L.) cultivar 'Willamette' was studied. ProCa increased while canes removal decreased chlorophylls and carotenoids content compared to control. POD, CAT, and PPO activities in leaves after removal of young canes were higher compared to control (2-4 times) which was visually confirmed for POD by isoelectrofocusing. Removal of young canes slithly increased, while ProCa significantly enhanced SOD activity in leaves compared to control (475.10 and 218.38 nkat mg^-1 prot, respectively). Pattern of SOD activity in fruit was similar as in leaf with substantial increase compared to control (about 15 times). Combination of implemented measures increased activity of all enzymes in the leaves and fruits. Our study could provide a better knowledge of the ProCa and canes removal influences on the action of enzymes in order to regulate their activities in fruit products.

Combined effect of Cd and Pb spiked field soils on bioaccumulation, DNA damage, and peroxidase activities in Trifolium repens

The present study was designed to investigate the combined effects of Cd and Pb on accumulation and genotoxic potential in white clover (Trifolium repens). For this purpose, T. repens was exposed to contaminated soils (2.5-20 mg kg(-1) cadmium (Cd), 250-2000 mg kg(-1) lead (Pb) and a mixture of these two heavy metals) for 3, 10 and 56 days. The resulting bioaccumulation of Cd and Pb, DNA damage (comet assay) and peroxidase activities (APOX and GPOX) were determined. The exposure time is a determinant factor in experiments designed to measure the influence of heavy metal contamination. The accumulation of Cd or Pb resulting from exposure to the two-metal mixture does not appear to depend significantly on whether the white clover is exposed to soil containing one heavy metal or both. However, when T. repens is exposed to a Cd/Pb mixture, the percentage of DNA damage is lower than when the plant is exposed to monometallic Cd. DNA damage is close to that observed in the case of monometallic Pb exposure. Peroxidase activity cannot be associated with DNA damage under these experimental conditions.

[Effect of salicylic acid on photosynthesis, physio-biochemistry and quality of Panax ginseng under full sun shine in spring]

In order to search for a new pathway to improve the yield of ginseng through growing at the full sun shine accompanied by salicylic acid (SA), the net photosynthetic rate (P(n)), superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), malondialdehyde (MDA) in Panax ginseng leaves, and the content of ginsenosides in roots were compared under various concentrations of SA and full sun shine with the traditional shade shed. Under the full sun shine, 0.05, 0.2 mmol x L(-1) SA increased net photosynthetic rate to a great extent. Under the cloudy day, the average net photosynthetic rate increased by 127.8% and 155.0% over the traditional shade shed, 13.9% and 27.5% over the treatment without SA respectively; under the clear day, 23.5% and 30.4% over the traditional shade shed, 8.6% and 14.6% over the treatment without SA, particularly obvious in the morning and late afternoon. With such concentration, SA increased activities of SOD, CAT, POD, and decreased the contents of the MDA. This difference resulted from different light intensity, rise of light saturation point, and fall of compensation point. Full sun shine decreased ginsenosides contents, but with SA, the ginsenosides regained, the content of Rg1 and Re, Rb1, total six types of ginsenosides in SA 0.2 mmol x L(-1) group were higher than those in the control group (P < 0.05) and other groups. The application of 0.2 mmol x L(-1) SA under full sun shine during a short time has little threat to the P. ginseng in spring, and could enhance the resistance to the adversity, which would improve the yield of ginseng heavily.

Correlation between the serum and tissue levels of oxidative stress markers and the extent of inflammation in acute appendicitis

OBJECTIVES

To determine the serum and tissue levels of markers of impaired oxidative metabolism and correlate these levels with the histopathology and Alvarado score of acute appendicitis patients.

METHOD

Sixty-five acute appendicitis patients (mean age, 31.4±12.06 years; male/female, 30/35) and 30 healthy control subjects were studied. The Alvarado score was recorded. Serum samples were obtained before surgery and 12 hours postoperatively to examine the total antioxidant status, total oxidant status, paraoxonase, stimulated paraoxonase, arylesterase, catalase, myeloperoxidase, ceruloplasmin, oxidative stress markers (advanced oxidized protein products and total thiol level) and ischemia-modified albumin. Surgical specimens were also evaluated.

RESULTS

The diagnoses were acute appendicitis (n = 37), perforated appendicitis (n = 8), phlegmonous appendicitis (n = 12), perforated+phlegmonous appendicitis (n = 4), or no appendicitis (n = 4). The Alvarado score of the acute appendicitis group was significantly lower than that of the perforated+phlegmonous appendicitis group (p = 0.004). The serum total antioxidant status, total thiol level, advanced oxidized protein products, total oxidant status, catalase, arylesterase, and ischemia-modified albumin levels were significantly different between the acute appendicitis and control groups. There was no correlation between the pathological extent of acute appendicitis and the tissue levels of the markers; additionally, there was no correlation between the tissue and serum levels of any of the parameters.

CONCLUSIONS

The imbalance of oxidant/antioxidant systems plays a role in the pathogenesis acute appendicitis. The Alvarado score can successfully predict the presence and extent of acute appendicitis.

Mannitol-induced drought stress on calli of Trigonellafoenum-graecum L. Var. RMt-303

Different explants of fenugreek, T. foenum-graecum L. (Var. RMt-303), were compared for their callus induction and subsequent shoot regeneration capabilities on Murashige and Skoog media supplemented with different phytohormones in varying concentration. The highest percentage of callus induction frequency was observed in 1 ppm benzylaminopurine (BAP). Maximum shoots were induced on media supplemented with 0.5 ppm BAP using leaf and stem tissues as explants. However, root tissues showed only callusing with no subsequent shooting. Cotyledonary node responded better than hypocotyls in terms of shoot induction on media supplemented with thidiazuron (0.1 ppm). The callus was subjected to drought stress as simulated by reduced water potential of growth media due to addition of mannitol. Calli could withstand -2 MPa water potential till 30 days indicating that the drought stress tolerance mechanisms are functional in this variety. Chlorophyll a and b and total chlorophyll, proline and total phenolic contents, total peroxidase and catalase activities increased under stress conditions suggesting the tolerance of callus to drought stress. However, ascorbate peroxidase, guaiacol peroxidase activities were found to decrease slightly. Malondialdehyde and H2O2 contents were found to decrease while only a slight disturbance was found in membrane stability index. These results underline the mechanisms that are crucial for drought stress tolerance in fenugreek.

Assessment of the degree of interference of polyphenolic compounds on glucose oxidation/peroxidase assay

The glucose oxidase/peroxidase assay (GOP) is a coupled enzymatic assay commonly used in measuring glucose concentrations in biological sciences and food chemistry, particularly for quantification of α-glucosidase activity. However, we found that the GOP assay is prone to interference, especially from reducing substances such as polyphenolic compounds, which are commonly found in botanical materials. To establish the scope and limitation of the assay in measuring α-glucosidase inhibition activity, we systematically investigated the structural features of the polyphenolic compounds that can lead to false positives. Utilizing sodium dodecyl sulfate (SDS) as surrogate for the meriquinone intermediate formed during the reaction, we measured the reactivity of this redox active intermediate toward common flavonoids. Our results show that flavonoids with o-dihydroxy groups in the B-ring cause strong interference and that compounds with little DPPH scavenging activity do not have interference. Our results highlight the need for checking the suitability of the GOP assay first before it is applied in measuring α-glucosidase inhibition activity. In addition, when the literature data on α-glucosidase inhibition activity of botanical extracts or polyphenolic compounds using GOP assay are interpreted, potential false positives due to interference on the assay will need to be taken into consideration.

Spectrophotometric determination of sulfide based on peroxidase inhibition by detection of purpurogallin formation

This paper presents a new method for spectrophotometirc detection of sulfide applying fungal peroxidase immobilized on sodium alginate. The sensing scheme was based on decrease of the absorbance of the orange compound, purpurogallin produced from pyrogallol and H2O2 as substrates, due to the inhibition of peroxidase by sulfide. Absorbance of purpurogallin was detected at 420nm by using a spectrophotometer. The proposed method could successfully detect the sulfide in the concentration range of 0.6-7.0μM with a detection limit of 0.4μM. The kinetic parameters of Michaelis-Menten with and without sulfide were also calculated. Possible inhibition mechanism of peroxidase by sulfide was deduced according to the variation of parameters and uncompetitive mechanism was observed with respect to hydrogen peroxide. The current method provides an easy to use method for sulfide detection in water samples.

Molecular and biochemical studies on the effect of gamma rays on lead toxicity in cowpea (Vigna sinensis) plants

The effect of lead acetate in the presence or absence of cowpea seeds irradiated with gamma rays on morphological criteria, protein electrophoresis, isozymes, and random amplification of polymorphic DNA-polymerase chain reaction (RAPD-PCR) of leaves was investigated. A highly significant decrease in shoot and root length was observed upon lead acetate exposure (300 and 600 μM). On the other hand, in seeds irradiated with gamma rays (2, 5, and 8 krad), these morphological parameters were increased after lead acetate treatments. Meanwhile, all treatments (lead acetate and gamma rays) caused variations in number, intensity, and/or density of SDS electrophoretic bands of proteins. In addition, electrophoretic studies of esterase, acid phosphatase, peroxidase, polyphenol oxidase, catalase, and superoxide dismutase isozyme activities were increased with increasing the concentrations of lead acetate and gamma ray doses. The variation in DNA profile in response to lead acetate and gamma irradiation treatments was detected by RAPD-PCR technique. The result of RAPD analysis using the five primers indicated the appearance and disappearance of DNA polymorphic bands at all treatments (gamma rays and lead stress). The relatively high concentrations of lead acetate (600 μM) induced more changes in genomic DNA pattern.

Identification of various laccases induced by anthracene and contribution to its degradation in a Mediterranean coastal pine litter

Mediterranean coastal ecosystems are known to be highly subject to natural and anthropic environmental stress. In this study, we examine the effects of anthracene as a common pollutant on the total microbial communities from a Pinus halepensis litter of a typical Mediterranean coastal site (Les Calanques, Marseille). The main objective was to identify the microbial factors leading the resilience of this ecosystem. Two questions were addressed: (i) how lignin-degrading enzymes (Laccase, Lignin-peroxidase and Mn-peroxidase) are affected by the presence of this molecule, (ii) whether the indigenous consortia are involved in its degradation in mesocosms under favorable incubation conditions (25 °C, 60% WHC) and after different time intervals (1 and 3 month(s)). We found a strong increase in laccase production in the presence of anthracene after 3 months, together with anthracene degradation (28%±5). Moreover 9,10-anthraquinone is detected as the product of anthracene oxidation after 3 months. However neither lignin-peroxidase activity nor Mn-peroxidase activity is detected. Laccase proteins directly extracted from litter were sequenced via Nano-LC-MS/MS and reveal twelve different peptide sequences induced by the presence of anthracene in the mesocoms. Our study confirms the major detoxification role of this enzymatic system and highlights the high degradation potential of fungal species inhabiting P. halepensis litter, a factor in the resilience of Mediterranean ecosystems.

Enzymatic basis for fungicide removal by Elodea canadensis

PURPOSE

Plants can absorb a diversity of natural and man-made toxic compounds for which they have developed diverse detoxification mechanisms. Plants are able to metabolize and detoxify a wide array of xenobiotics by oxidation, sugar conjugation, glutathione conjugation, and more complex reactions. In this study, detoxification mechanisms of dimethomorph, a fungicide currently found in aquatic media were investigated in Elodea canadensis.

METHODS

Cytochrome P450 (P450) activity was measured by an oxygen biosensor system, glucosyltransferases (GTs) by HPLC, glutathione S-transferases (GSTs), and ascorbate peroxidase (APOX) were assayed spectrophotometrically.

RESULTS

Incubation of Elodea with dimethomorph induced an increase of the P450 activity. GST activity was not stimulated by dimethomorph suggesting that GST does not participate in dimethomorph detoxification. In plants exposed to dimethomorph, comparable responses were observed for GST and APOX activities showing that the GST was more likely to play a role in response to oxidative stress. Preincubation with dimethomorph induced a high activity of O- and N-GT, it is therefore likely that both enzymes participate in the phase II (conjugation) of dimethomorph detoxification process.

CONCLUSIONS

For the first time in aquatic plants, P450 activity was shown to be induced by a fungicide suggesting a role in the metabolization of dimethomorph. Moreover, our finding is the first evidence of dimethomorph and isoproturon activation of cytochrome P450 multienzyme family in an aquatic plant, i.e., Elodea (isoproturon was taken here as a reference molecule). The detoxification of dimetomorph seems to proceed via hydroxylation, and subsequent glucosylation, and might yield soluble as well as cell wall bound residues.

Effect of aluminium uptake on physiology, phenols and amino acids in Matricaria chamomilla plants

Chamomile is a widely used medicinal plant and, as observed in our previous studies, also accumulates some metals in its above-ground biomass. We therefore tested selected metabolic responses after treatments with 60 and 120 microM Al for 7 days. Shoot Al content was not elevated in comparison with control (12.3-14.1 microg g(-1) DW) while total root Al increased strongly, reaching 2680 and 4400 microg g(-1) DW in 60 and 120 microM treatments, respectively. "Intra-root" Al represented 83.6 (60 microM treatment) and 75.8% (120 microM treatment) of total root Al. Soluble proteins were not significantly affected. Free amino acids were almost unaffected in shoots while in roots the highest content was found in 60 microM Al. Ascorbate- and guaiacol-peroxidase activities were the highest in 60 microM Al-exposed roots. On the other hand, phenylalanine ammonia-lyase activity, total soluble phenols, flavonoids, a sum of 13 phenolic acids and partially two flavonols (quercetin and kaempferol) increased in the shoots. Present study has shown lower Al toxicity and unaltered shoot Al content seems to be the most positive outcome in comparison with previously tested metals (Cd, Ni and Cu). Our results indicate that phenols in shoots and free amino acids in roots are influenced by Al excess in chamomile plants. Possible mechanisms in the context of available literature are suggested and discussed.

Accumulation and acute toxicity of silver in Potamogeton crispus L

In the present study, Potamogeton crispus L. plants exposed to various concentrations of silver (Ag) (5, 10, 15, and 20 microM) for 5d were investigated to determine the accumulating potential of Ag and its influence on nutrient elements, chlorophyll pigments and fluorescence, various antioxidant enzymes and compounds, adenosine triphosphate (ATP), protein content and ultrastructure. The accumulation of Ag was found to increase in a concentration dependent manner with a maximum of 29.3 microg g(-1) at 20 microM. The nutrient elements (except Ca), photosynthetic pigments, chlorophyll a fluorescence parameters (Fo, Fv, Fv/Fm, Fv/Fo), malondialdehyde (MDA), ATP, peroxidase (POD) activity, ascorbate (AsA), reduced glutathione (GSH) and protein contents decreased significantly as concentration of Ag augmented. In contrast, an induction in SOD activity was recorded, while an initial rise in Ca content and CAT activity was followed by subsequent decline. Morphological symptoms of senescence phenomena such as chlorosis and damage of chloroplasts and mitochondria were observed even at the lowest concentration of Ag, which suggested that Ag hastened the senescence of the tested plants. The loss of nutrients and chlorophyll content and damage of chloroplasts were associated with disturbances in photosynthetic capacity as indicated by the quenching of chlorophyll a fluorescence. Decreased chlorophyll and protein contents suggest oxidative stress induced by Ag. In addition, both the reduction of ATP and the damage to the ultrastructure of organelles were indicative of general disarray in the cellular functions exerted by Ag.

Morphology and oxidative physiology of boron-deficient mulberry plants

The aim of the study was to induce B deficiency symptoms and to relate the generation of reactive oxygen species (ROS) and altered cellular redox environment with the effects of B deficiency in mulberry (Morus alba L.) cv. Kanva-2 plants. Study was undertaken on antioxidant responses, malondialdehyde (MDA) content as an indicator of oxidative damage and ratio of dehydroascorbate (DHA) to ascorbic acid (AsA) as an index of cellular redox environment in B-deficient (0.0 microM) and B-supraoptimal (33 microM) mulberry plants. B deficiency symptoms appeared as upward cupping of the young emerging leaves. Later on, B-deficient plants developed lenticels like cracks on major vein, petiole and stem. B-deficient leaves had higher water potential (Psi) and relative water content (RWC), contained a lower concentration of B, less chloroplastic pigments and high tissue Fe, Mn and Zn concentrations compared to the controls. Hydrogen peroxide was accumulated in leaves of B-deficient and B-supraoptimal plants. B-supraoptimal plants also showed an increased DHA/AsA ratio. The activities of superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), peroxidase (POD, EC 1.11.1.7) and ascorbate peroxidase (APX, EC 1.11.1.11) were increased in B-deficient leaves. The activities of SOD and POD were decreased in B-supraoptimal plants. The results suggest that B deficiency aggravates oxidative stress through enhanced generation of ROS in mulberry plants.

Iron-induced oxidative stress in a macrophyte: a chemometric approach

Iron-induced oxidative stress in plants of Bacopa monnieri L., a macrophyte with medicinal value, was investigated using the chemometric approach. Cluster analysis (CA) rendered two distinct clusters of roots and shoots. Discriminant analysis (DA) identified discriminating variables (NP-SH and APX) between the root and shoot tissues. Principal component analysis (PCA) results suggested that protein, superoxide dismutase (SOD), ascorbic acid, proline, and Fe uptake are dominant in root tissues, whereas malondialdehyde (MDA), guaiacol peroxidase (POD), cysteine, and non-protein thiol (NP-SH) in shoot of the stress plant. Discriminant partial-least squares (DPLS) results further confirmed that SOD and ascorbic acid contents dominated in root tissues, while NP-SH, cysteine, POD, ascorbate peroxidase (APX), and MDA in shoot. MDA and NP-SH were identified as most pronounced variables in plant during the highest exposure time. The chemometric approach allowed for the interpretation of the induced biochemical changes in plant tissues exposed to iron.

An increasing the resistance of field tomato to Pepino mosaic virus

A resistance degree of three cultivars: 'Atol', 'Betalux' and 'Promyk' of Lycopersicon esculentum Mill. to the pathogen was investigated. The most susceptible to Pepino mosaic virus (PepMV) turned out to be the 'Betalux' cultivar, therefore it was chosen for further studies. For this cultivar, under the transmission electron microscope, a few particles of the virus were observed in leaves, and many virions arranged in the form of the bundle--in fruits. An influence of two inducers was examined--benzothiadiazole (BTH) dissolved in the water and chitosan dissolved in the acetic acid as well as the influence of milk with the addition of the acetic acid on the degree of the disease development. Different testing methods were applied: measuring the percentage of leaf surface covered by necroses and yellow spots as well as the percentage of infected area on fruits, detecting the presence of 3.3'-diaminobenzidine peroxidase, hydrogen peroxide and lignin in leaves with colourful histochemical reactions. It was stated that the 0.5 mM solution of BTH induced the highest increase in the systemic acquired resistance (SAR)--mainly in fruits, which were least infected by the virus. The upper leaves, growing above the BTH treatment zone, were also highly protected. The milk with the acetic acid had no influence on improving the condition of younger leaves (growing above the level of sprayed leaves). However, it contributed in a high degree, though a little bit lower than in case of BTH, to the protection of the tomato fruits. Natural resistance of the 'Promyk' cultivar is correlated with the higher level of hydrogen peroxide, the higher activity of the peroxidase and the greater accumulation of the lignin than in case of the susceptible cultivar--'Betalux'. BTH induced defensive reactions at susceptible cultivar of the tomato, which correlated with an increase in the level of the above mentioned indicators of plants resistance, especially of hydrogen peroxide.

Non-enzymatic and enzymatic antioxidant variations in tender and mature leaves of Strychnos nux-vomica L. (Family: Loganiaceae)

In the present investigation, Strychnos nux-vomica, an important plant used in traditional medicine, was evaluated for its antioxidant potential. The antioxidant potentials were examined in terms of non-enzymatic antioxidant molecules and activities of antioxidant enzymes. The non-enzymatic antioxidant molecules studied were ascorbic acid, alpha-tocopherol and reduced glutathione. The estimated antioxidant enzymes were superoxide dismutase, ascorbate peroxidase, catalase, peroxidase and polyphenol oxidase. The analyses were carried out in the field-collected leaf samples. It was found that plant contained a significant quantity of non-enzymatic and enzymatic antioxidants in the leaves. These findings have high significance in the pharmacological industry; however, a detailed investigation is needed to confirm this conclusion, by radical scavenging ability, which is underway in our laboratory.

Oxidative stress in duckweed (Lemna minor L.) caused by short-term cadmium exposure

The mechanisms of plant defence against cadmium toxicity have been studied by short-term exposure of Lemna minor L. (common duckweed) to concentrations of CdCl2 ranging from 0 to 500microM. High accumulation of cadmium was observed (12,320+/-2155microgg(-1) at 500microM CdCl2), which caused a gradual decrease of plant growth, increased lipid peroxidation, and weakened the entire antioxidative defence. Total glutathione concentration decreased significantly; however, the concentration of oxidized glutathione remained stable. The responses of four antioxidant enzymes showed that catalase was the most inhibited after CdCl2 exposure, ascorbate peroxidase and guaiacol peroxidase moderately, and glutathione reductase least. The total antioxidative potential revealed an induced antioxidative network at 0.1microM CdCl2 (137+/-13.2% of the control) and its reduction to only 47.4+/-4.0% of the control at higher cadmium concentrations. The possible application of the examined biomarkers in ecotoxicological research is discussed.

Effect of Ginkgo biloba on the reproductive outcome and oxidative stress biomarkers of streptozotocin-induced diabetic rats

The aim of the present study was to evaluate the effect of Ginkgo biloba treatment (EGb 761, 200 mg kg-1 day-1) administered from day 0 to 20 of pregnancy on maternal reproductive performance and on the maternal and fetal liver antioxidant systems of streptozotocin-induced diabetic Wistar rats. On day 21 of pregnancy, the adult rats (weighing approximately 250 +/- 50 g, minimum number = 13/group) were anesthetized to obtain maternal and fetal liver samples for superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and total glutathione (GSH-t) determinations. The uterus was weighed with its contents. The diabetic (G3) and treated diabetic (G4) groups of rats presented significant maternal hyperglycemia, reduced term pregnancy rate, impaired maternal reproductive outcome and fetal-placental development, decreased GSH-Px (G3 = G4 = 0.6 +/- 0.2) and SOD (G3 = 223.0 +/- 84.7; G4 = 146.1 +/- 40.8), and decreased fetal CAT activity (G3 = 22.4 +/- 10.6; G4 = 34.4 +/- 14.1) and GSH-t (G3 = G4 = 0.3 +/- 0.2), compared to the non-diabetic groups (G1, untreated control; G2, treated). For G1, maternal GSH-Px = 0.9 +/- 0.2 and SOD = 274.1 +/- 80.3; fetal CAT = 92.6 +/- 82.7 and GSH-t = 0.6 +/- 0.5. For G2, G. biloba treatment caused no toxicity and did not modify maternal or fetal-placental data. EGb 761 at the nontoxic dose used (200 mg kg-1 day-1), failed to modify the diabetes-associated increase in maternal glycemia, decrease in pregnancy rate, decrease in antioxidant enzymes, and impaired fetal development when the rats were treated throughout pregnancy (21 days).

Critical view on the monochlorodimedone assay utilized to detect haloperoxidase activity

The current study aimed to identify the halogenating enzymes involved in the biosynthesis of the ambigols A, B, C and tjipanazole D, isolated from the cyanobacterium Fischerella ambigua. Haloperoxidase (HPO) activity within F. ambigua was therefore assayed spectrophotometrically by using monochlorodimedone (MCD) during protein purification. This strategy revealed the isolation of a protein positive in the MCD-assay, but an involvement in halogenating processes could not be verified. N-terminal sequencing rather demonstrated homology to cytochrome c(6) from other cyanobacteria and green algae. From our findings it thus has to be concluded that the spectrophotometrical MCD-assay routinely used to detect HPO activity may yield false positive results, mainly since the assay focuses on the decline of the educt and not on the formation of the product. Our data indicate that the reaction of MCD with proteins of the cytochrome c- family leads to unspecific products.

An anamorph of the white-rot fungus Bjerkandera adusta capable of colonizing and degrading compact disc components

A Geotrichum-like fungus isolated from a biodeteriorated compact disc (CD) was able to degrade in vitro the components of different CD types. The fungal hyphae inside the CD fragments grew through the aluminium layer and produced the solubilization of this metal. Furthermore, examination of CDs by scanning electron microscopy showed that the fungus was able to destroy the pits and lands structures grooved in the polycarbonate layer, confirming degradation of this aromatic polymer. The fungus secretes aryl-alcohol oxidase and Mn2+-oxidizing peroxidase, two kinds of oxidoreductases characteristic of ligninolytic basidiomycetes. Analysis of the ITS region of ribosomal DNA, as well as the morphological characteristics, the lack of sexual forms and the profile of enzymes secreted in liquid medium identified the fungus as a Geotrichum-like anamorph of Bjerkandera adusta (Willd.) P. Karst.

Lead toxicity in alfalfa plants exposed to phytohormones and ethylenediaminetetraacetic acid monitored by peroxidase, catalase, and amylase activities

This manuscript describes the toxicity of lead in alfalfa plants treated with ethylenediaminetetraacetic acid (EDTA) and the phytohormones indole-3-acetic-acid (IAA), gibberellic acid (GA), and kinetin (KN), on catalase (CAT), ascorbate peroxidase (APOX), and total amylase activity (TAA). In all cases Pb was used at 40 mg/L; EDTA at 0.2 mM (equimolar to Pb); and IAA, GA, and KN at 1, 10, and 100 microM, respectively. An experiment containing Pb at 40 mg/L, 0.2 mM EDTA, and IAA and KN at 100 microM each was performed to determine changes in TAA. A control (plain nutrient solution) also was used for comparison. In all cases the treatments were performed in triplicate. Standard procedures were followed to determine the activity of the respective enzymes. After 10 d of exposure to the treatments, the leaves were harvested, homogenized, and centrifuged, and the supernatants were analyzed for CAT, APOX, and TAA. All determinations were performed in triplicate. The results demonstrated that CAT was reduced significantly (p < 0.05) by all treatments containing Pb, IAA, and GA at 10 and 100 microM. However, only the treatments Pb/EDTA/KN at 1, 10, and 100 microM reduced the APOX. The TAA in leaves of alfalfa plants was increased significantly (p < 0.05) by all treatments. Overall, the results suggest that the CAT tests showed no lead toxicity to the alfalfa seedlings. However IAA at 10 and 100 muM revealed toxicity to the CAT enzyme. In addition, the APOX tests exhibited no toxicity to the peroxidase enzyme with the exception of Pb/EDTA/KN treatments. Finally, the TAA tests showed high Pb/EDTA/phytohormone toxicity to the amylase enzyme in alfalfa seedlings.

The use of isobaric tag peptide labeling (iTRAQ) and mass spectrometry to examine rare, primitive hematopoietic cells from patients with chronic myeloid leukemia

Chronic Myeloid Leukemia (CML) is a hematopoietic stem cell disease, associated with a t(9, 22) chromosomal translocation leading to formation of the BCR/ABL chimeric protein, which has an intrinsic tyrosine kinase activity. Recently, the BCR/ABL tyrosine kinase inhibitor imatinib mesylate (imatinib) has been successfully used clinically, although, disease relapse can still occur. The precise detail of the mechanism by which CML cells respond to imatinib is still unclear. We therefore systematically examined the effects of imatinib on the primitive CML cell proteome, having first established that the drug inhibits proliferation and induces increased apoptosis and differentiation. To define imatinib-induced effects on the CML proteome, we employed isobaric tag peptide labeling (iTRAQ) coupled to two-dimensional liquid chromatography/tandem mass spectrometry. Given the limited clinical material available, the isobaric tag approach identified a large population of proteins and provided relative quantification on four samples at once. Novel consequences of the action of imatinib were identified using this mass spectrometric approach. DEAD-box protein 3, heat shock protein 105 kDa, and peroxiredoxin-3 were identified as potential protein markers for response to imatinib.

Protein changes in the albedo of citrus fruits on postharvesting storage

In this work, major protein changes in the albedo of the fruit peel of Murcott tangor (tangerine x sweet orange) during postharvest ageing were studied through 2D PAGE. Protein content in matured on-tree fruits and in fruits stored in nonstressing [99% relative humidity (RH) and 25 degrees C], cold (99% RH and 4 degrees C), and drought (60% RH and 25 degrees C) conditions was initially determined. Protein identification through MS/MS determinations revealed in all samples analyzed the occurrence of manganese superoxide dismutase (Mn SOD), actin, ATP synthase beta subunit (ATPase), citrus salt-stress associated protein (CitSap), ascorbate peroxidase (APX), translationally controlled tumor protein (TCTP), and a cysteine proteinase (CP) of the papain family. The latter protein was identified in two different gel spots, with different molecular mass, suggesting the simultaneous presence of the proteinase precursor and its active form. While Mn SOD, actin, ATPase, and CitSap were unchanged in the assayed conditions, TCTP and APX were downregulated during the postharvest ageing process. Ageing-induced APX repression was also reversed by drought. CP contents in albedo, which were similar in on- and off-tree fruits, were strongly dependent upon cold storage. The active/total CP protein ratio significantly increased after cold exposure. This proteomic survey indicates that major changes in protein content in the albedo of the peel of postharvest stored citrus fruits are apparently related to the activation of programmed cell death (PCD).

Role of peroxidases, thiols and Bak/Bax in tumor cell susceptibility to Cu[DEDTC]2

Copper and two molecules of diethyl dithiocarbamate [DEDTC] form the Cu[DEDTC](2) complex, which shows cytotoxicity against melanoma and carcinoma cells, making it a potentially useful anti-cancer agent. The differential response to Cu[DEDTC](2) in susceptible human SKBR3 carcinoma and C8161 melanoma cell variants of moderate and high resistance to this organometallic complex was evaluated in this study. Both cell lines underwent apoptosis-associated PARP cleavage, changes in expression of nuclear NFkB p65, p21WAF1 and cyclin A, with loss of clonogenicity in response to this agent. However, a threefold greater concentration [IC(50) 0.6 microM DEDTC: 0.3 microM Cu] was required to kill moderately resistant C8161 melanoma compared to highly susceptible SKBR3 cells. Decreased susceptibility to Cu[DEDTC](2) in C8161 melanoma correlated with greater levels of glutathione peroxidase and catalase, and a fourfold lower requirement for N-acetyl cysteine (1mM) to overcome toxicity. Whereas melanoma cells selected for resistance to [0.8 microM DEDTC: 0.4 microM Cu] showed persistent catalase and GPx activity, melanoma cells with moderate susceptibility showed decreased catalase and Gpx when responding to treatment. Cytotoxic response in moderately susceptible C8161 melanoma cells involved an early accumulation of pro-apoptotic Bax in the G2 cell cycle phase, followed by an increased ratio of pro-apoptotic Bak to anti-apoptotic Mcl-1 in mitochondria. Our data suggests that Cu[DEDTC](2) toxicity is mediated through an increase in pro-apoptotic Bak/Bax via disruption of the peroxide and thiol metabolism.

Characterization of a fungal strain isolated from a polyphenol polluted site

A group of fungal strains were isolated from a polyphenol polluted soil, taken from an olive oil processing plant in Attica, Greece. The fungi were tested for their ability to decolorize a polyaromatic dye Poly R-478, which was used as a model compound to test their ligninolytic activities. The strain K1.1 decolorized efficiently the dye on agar plates and was further studied. PCR amplification of the internal transcribed spacer (ITS) region of the ribosomal RNA genes from the genomic DNA isolated from mycelium grown in liquid culture resulted in amplified fragments. Via BLASTN search, the length of a 773 base pairs was identified as the basidiomycetes Coprinellus xanthothrix. The growth rates and the tolerance of the fungus were compared on solid media, containing four different concentrations of pentachlorophenol. Extracellular enzyme activities (lignin peroxidase, manganese peroxidase and laccase) were determined in defined liquid medium. The isolate expressed laccase and manganese peroxidase but not lignin peroxidase. The removal of the dye was also estimated in liquid medium. The fungus showed biosorption and biotransformation as removal mechanisms.

Structural motifs of syringyl peroxidases are conserved during angiosperm evolution

The most distinctive variation in the monomer composition of lignins in vascular land plants is that between the two main groups of seed plants. Thus, whereas gymnosperm (softwood) lignins are typically composed of guaiacyl (G) units, angiosperm (hardwood) lignins are largely composed of similar levels of G and syringyl (S) units. However, there are some studies that suggest that certain angiosperm peroxidases are unable to oxidize sinapyl alcohol, and a coniferyl alcohol shuttle has been proposed for oxidizing S units during the biosynthesis of lignins. With this in mind, a screening of the presence of S peroxidases in angiosperms (including woody species and forages) was performed. Contrarily to what might be expected, the intercellular washing fluids from lignifying tissues of 25 woody, herbaceous, and shrub species, belonging to both monocots and dicotyledons, all showed both S peroxidase activities and basic peroxidase isoenzymes analogous, with regard the isoelectric point, to the Zinnia elegans basic peroxidase isoenzyme, the only S peroxidase that has been fully characterized. These results led to the protein database in the search for homologies between angiosperm peroxidases and a true eudicot S peroxidase, the Z. elegans peroxidase. The findings showed that certain structural motifs of S peroxidases are conserved within the first 15 million years of angiosperm history, because they are found in peroxidases from the two major lineages of flowering plants, eumagnoliids and eudicotyledons, of note being the presence of these peroxidases in Amborella and Nymphaeales, which represent the first stages of angiosperm evolution. These phylogenetic studies also suggest that guaiacyl peroxidases apparently constitute the most "evolved state" of the plant peroxidase family evolution.

[Primary effects on Isatis indigotica after spaceflight]

Isatis indigotica carried by the Chinese first spaceship "Shenzhou" was studied in order to find the mutation after spaceflight. TLC differentiation experiments showed no distinct discrepancy among the samples of spaceflight and non-space-flight, and the same color spot appeared corresponding to the location of the arginine. Isoenzymes of esterase and peroxidase were studied with PAGE. Isoenzymes of esterase were difference among the samples. To peroxidases, little difference was found with them. The ratio of dry weight and extract contents showed out the mutation has emerged after spaceflight, but some characters were unstable. It is necessary for further study.

Soft landed protein voltammetry

The present work illustrates a new method: soft landed protein voltammetry (SLPV); this experimental procedure is based on the coupling of ion soft landing with a voltammetric technique and allows the electrode surface to be functionalized with biologically active molecules, thus opening up numerous new perspectives ranging from molecular electronics to protein chips.

Proteomic identification and characterization of bacterial factors associated with Burkholderia cenocepacia survival in a murine host

Burkholderia cenocepacia is a member of the Burkholderia cepacia complex, a diverse family of Gram-negative bacteria that are serious respiratory pathogens in immunocompromised patients and individuals with cystic fibrosis. To identify putative bacterial virulence determinants, proteomic profiles were compared between two B. cenocepacia isolates that demonstrated differential persistence in a mouse model of pulmonary infection; clinical isolate C1394 is rapidly cleared from the murine lung whereas the strain variant, C1394mp2, persists. Two-dimensional (2D) gel electrophoresis was used to identify candidate proteins involved in B. cenocepacia survival in a susceptible host. The 2D proteome of the persistent isolate (C1394mp2) revealed loss of an alkyl hydroperoxide reductase subunit C (AhpC) protein spot and increased production of flagellin proteins. Loss of AhpC expression in C1394mp2 correlated with enhanced susceptibility to oxidative stress. C1394mp2 expressed increased flagellin production and enhanced swimming motility, traits that were subject to regulation by heat and low pH. Together, these results revealed differential expression and stress regulation of putative virulence determinants associated with B. cenocepacia persistence in a susceptible host.

Characterization of vitamin A-storing cells in mouse fibrous kidneys using Cygb/STAP as a marker of activated stellate cells

The expression of the cytoglobin/stellate cell activation-associated protein (Cygb/STAP) was recently confirmed in all splanchnic vitamin A-storing cells--including hepatic stellate cells (HSCs)--in normal conditions. In the hepatic fibrous lesion, the expression of Cygb/STAP has been shown to be upregulated in activated HSCs and myofibroblasts (MFs), which have synthesized extracellular matrices. Furthermore, splanchnic vitamin A-storing cells have been reported to be distributed in the kidney. In this study, we clarify the contribution of vitamin A-storing cells to renal fibrosis by focusing on Cygb/ STAP. Adult mice were subjected to unilateral ureteral obstruction (UUO) and kidneys were harvested 1, 3, 7, and 10 days after UUO. Numbers of Cygb/STAP-immunopositive cells as well as Cygb/STAP mRNA 3 days after UUO (UUO day 3 kidney) increased. Vitamin A-autofluorescence was observed in intertubular spaces of controls but gradually declined in a time-dependent manner after UUO. Cygb/STAP+ cells were not completely identical with alpha-smooth muscle actin (alphaSMA)-positive cells in the control or UUO day 7 kidneys. Immunohistochemical analysis for Cygb/STAP and fibulin-2 (Fib), a specific marker for distinguishing MFs from activated HSCs, revealed that the number of Fib+STAP+ cells (MFs) and Fib-STAP+ cells (splanchnic vitamin A-storing cells) significantly increased in UUO day 3 and UUO day 7 kidneys compared with the controls. Our present findings support the concept that Cygb/STAP can be a unique marker for splanchnic fibroblast-like cells, namely the vitamin A-storing cell lineage, and suggest that splanchnic vitamin A-storing cells contribute to renal fibrogenesis in the obstructed kidney.

Structural motifs of syringyl peroxidases predate not only the gymnosperm-angiosperm divergence but also the radiation of tracheophytes

* The most distinctive variation in the monomer composition of lignins in vascular land plants is that found between the two main groups of seed plants. Thus, while gymnosperm lignins are typically composed of guaiacyl (G) units, angiosperm lignins are largely composed of similar levels of G and syringyl (S) units. * However, and contrary to what might be expected, peroxidases isolated from basal (Cycadales and Ginkgoales) and differentially evolved (Coniferales and Gnetales) gymnosperms are also able to oxidize S moieties, and this ability is independent of the presence or absence of S-type units in their lignins. * The results obtained led us to look at the protein database to search for homologies between gymnosperm peroxidases and true eudicot S-peroxidases, such as the Zinnia elegans peroxidase. * The findings showed that certain structural motifs characteristic of eudicot S-peroxidases (certain amino acid sequences and beta-sheet secondary structures) predate the gymnosperm-angiosperm divergence and the radiation of tracheophytes, since they are found not only in peroxidases from basal gymnosperms, ferns and lycopods, but also in peroxidases from the moss Physcomitrella patens (Bryopsida) and the liverwort Marchantia polymorpha (Marchantiopsida), which, as typical of bryophytes, do not have xylem tissue nor lignins.

Quantitative analysis of representative proteome components and clustering of Helicobacter pylori clinical strains

BACKGROUND

Several Helicobacter pylori proteins have been reported to be associated with severe symptoms of gastric disease. However, expression levels of most of these disease-associated proteins require further evaluation in order to clarify their relationships with gastric disease patterns. Representative proteome components of 71 clinical isolates of H. pylori were analyzed quantitatively to determine whether the protein expression levels were associated with gastric diseases and to cluster clinical isolates.

METHODS

After two-dimensional electrophoresis (2-DE) of H. pylori isolates, spot intensities were analyzed using pdquest 2-D Gel Analysis Software. The intensities of 10 representative protein spots, identified by peptide fingerprinting using matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) or peptide sequencing using quadrupole TOF MS, were subjected to the nonparametric Mann-Whitney test and hierarchical agglomerative cluster analysis. The relationship between clusters and gastric diseases was analyzed by the chi-squared test.

RESULTS

Although the spot intensities of the 10 representative proteins were highly variable within each gastric disease group, the expression levels of CagA, UreB, GroEL, EF-Tu, EF-P, TagD, and FldA showed some significant differences among the gastric disease patterns. On the basis of the 10 target protein intensities, hierarchical agglomerative cluster analysis generated a dendrogram with clusters indicative of chronic gastritis/gastric cancers and gastric/duodenal ulcers.

CONCLUSION

These results indicated that quantitative analysis of proteome components is a feasible method for examining disease-associated proteins and clustering clinical strains of H. pylori.

Lead detoxification by coontail (Ceratophyllum demersum L.) involves induction of phytochelatins and antioxidant system in response to its accumulation

Coontail (Ceratophyllum demersum L.) plants when exposed to various concentrations of Pb (1-100microM) for 1-7days, exhibited both phytotoxic and tolerance responses. The specific responses were function of concentration and duration. Plants accumulated 1748mugPbg(-1) dw after 7d which reflected its metal accumulation ability, however most of the metal (1222microgg(-1) dw, 70%) was accumulated after 1d exposure only. The toxic effect and oxidative stress caused by Pb were evident by the reduction in biomass and photosynthetic pigments and increase in malondialddehyde (MDA) content and electrical conductivity with increase in metal concentration and exposure duration. Morphological symptoms of senescence phenomena such as chlorosis and fragmentation of leaves were observed after 7d. The metal tolerance and detoxification strategy adopted by the plant was investigated with reference to antioxidant system and synthesis of phytochelatins. Protein and antioxidant enzymes viz., superoxide dismutase (SOD, EC 1.15.1.1), guaiacol peroxidase (GPX, EC 1.11.1.7) ascorbate peroxidase (APX, EC 1.11.1.11), catalase (CAT, EC 1.11.1.6) and glutathione reductase (GR, EC 1.6.4.2) showed induction at lower concentration and duration followed by decline. All enzymes except GPX showed maximum activity after 1d. An increase in cysteine, non-protein thiols (NP-SH) and glutathione (GSH) content was observed at moderate exposure conditions followed by decline. Phytochelatins (PC(2) and PC(3)) were synthesized to significant levels at 10 and 50microM Pb with concomitant decrease in GSH levels. Thus production of PCs seems important for the detoxification of metal, however it may lead to depletion of GSH and consequently oxidative stress. Results suggest that plants responded positively to moderate Pb concentrations and accumulated high amount of metal. Due to metal accumulation coupled with detoxification potential, the plant appears to have potential for its use as phytoremediator species in aquatic environments having moderate pollution of Pb.

The Prx Q protein ofArabidopsis thalianais a member of the luminal chloroplast proteome

Peroxiredoxins have been discovered in many organisms ranging from eubacteria to mammals, and their known biological functions include both oxidant defense and signal transduction. The genome of Arabidopsis thaliana encodes for ten individual peroxiredoxins, of which four are located in the chloroplast. The best-characterized member of the chloroplast peroxiredoxins is 2-Cys Prx that is associated with the stroma side of the thylakoid membrane and is considered to participate in antioxidant defense and protection of photosynthesis. This study addressed the chloroplast peroxiredoxin Prx Q and showed that its subcellular location is the lumen of the thylakoid membrane. To get insight in the biological function of the Prx Q protein of Arabidopsis, the protein levels of the Prx Q protein in thylakoid membranes were studied under different light conditions and oxidative stress. A T-DNA knockout mutant of Prx Q did not show any visible phenotype and had normal photosynthetic performance with a slightly increased oxygen evolving activity.

Differential Expression of Defense/Stress-Related Marker Proteins in Leaves of a Unique Rice Blast Lesion Mimic Mutant (blm)

We analyzed a unique rice (Oryza sativa L.) blast lesion mimic (blm) mutant for differentially expressed proteins in leaves of one- and two-week-old seedlings manifesting the lesion mimic phenotype. Gel-based one- and two-dimensional electrophoresis (1- and 2-DGE) was performed using leaves (blm and wild-type, WT) before (stage 1, S1) and after (stage 2, S2) lesion formation. 1-DGE immunoblotting revealed potent increase in the expression of a key pathogenesis-related (PR) marker biosynthetic enzyme, naringenin 7-O-methyltransferase, involved in rice phytoalexin sakuranetin biosynthesis, and three oxidative-stress-related marker proteins, catalase, ascorbate peroxidase (APX), and superoxide dismutase (SOD) in leaves of the blm mutant. 2-D gel immunoblotting analysis with anti-APX and anti-SOD antibodies revealed newly appearing cross-reacting protein spots in blm. 2-DGE analysis detected 50 Coomassie brilliant blue-stained protein spots differentially expressed in blm. A total of 23 and 44 protein spots was excised for analysis by N-terminal amino acid sequencing and nano-electrospray ionization liquid chromatography mass spectrometry, respectively; 26 nonredundant proteins were identified. The pathogenesis-related class 5 and 10 proteins, including a new OsPR10d protein, were significantly induced in blm. The OsPR5 protein spot was stained with Pro-Q Diamond phosphoprotein gel stain suggesting OsPR5 to be a putative phosphoprotein. Surprisingly, protein spot 20, a leaf OsPR10b, showed identity to a rice root-specific PR-10 (RSOsPR10). To resolve this discrepancy, we checked its expression in leaves of blm and WT (S1 and S2), respectively, using gene-specific primers and reverse transcriptase-polymerase chain reaction; RSOsPR10 mRNA was found to express in the leaves.

Effect of pretreatment of salt, copper and temperature on ultraviolet-B-induced antioxidants in diazotrophic cyanobacterium Anabaena doliolum

Effect of salt, copper, and temperature pretreatments on the UV-B-induced oxidative damage, measured in terms of peroxide and MDA (lipid peroxidation) contents, was studied in the diazotrophic cyanobacterium Anabaena doliolum. To understand the survival strategy enzymatic (superoxide dismutase, catalase, glutathione reductase, and ascorbate peroxidase) and non-enzymatic (glutathione, ascorbate, alpha-tocopherol and carotenoid) antioxidants were studied. Among the various pretreatments salt was found to decrease and copper and temperature pretreatments increased the deleterious effects of UV-B. This study is the first to demonstrate that physical stress (high temperature) enhanced the damaging effect of UV-B more profoundly than chemical stresses (salt and copper).

Oxidative/nitrosative stress and peroxiredoxin 2 are associated with grade and prognosis of human renal carcinoma

Peroxiredoxins (Prxs) 1-6 were assessed in 138 renal cell carcinomas (RCC) using immunohistochemistry and selected samples by Western blotting analysis. Oxidative/nitrosative damage was evaluated using nitrotyrosine immunoreactivity. The expressions of Prxs were correlated with tumor grade and survival and nitrotyrosine reactivity. Non-malignant kidney tubular cells showed positivity with variable intensity for all six Prxs. In RCCs, most cases were positive for Prxs 1 and 2, while only 15-20% of tumors showed expression for Prxs 3 and 4. Prx 2 was associated with tumors of a lower grade (p=0.009) and with a lower frequency of distant metastases (p=0.046). Patients with tumors expressing Prx2 had better prognosis (p=0.027). Instead, nitrotyrosine was significantly associated with high grade tumors (p=0.001). Compared with the non-malignant kidney tubular cells, low Prx expression in the tumor cells can make them more susceptible to oxidative damage. Prx 2 was more abundantly expressed in low grade tumors, suggesting that this protein could play a role in preventing the development of oxidative damage, which in turn can lead to the activation of pathways leading to aggressive tumors.

Involvement of reactive oxygen species in the action of ciprofloxacin against Escherichia coli

Ciprofloxacin is an important and commonly used member of the fluoroquinolone group of antibiotics. Ciprofloxacin inhibits DNA topoisomerase II and DNA topoisomerase IV activities, eventually leading to bacterial cell death. In addition, an increase of reactive oxygen species in the bacterial cells in response to ciprofloxacin has been shown. We investigated the role of reactive oxygen species in the antibacterial action of ciprofloxacin by studying the effects of different antioxidant compounds on ciprofloxacin susceptibility of Escherichia coli. Among the antioxidants checked, glutathione and ascorbic acid provided substantial protection against ciprofloxacin. The involvement of superoxide anion (O2-) and hydrogen peroxide (H2O2) in the antibacterial action of ciprofloxacin was analyzed using superoxide dismutase, catalase, and alkyl hydroperoxide reductase knockout strains of E. coli. The effects of multicopy sod genes on ciprofloxacin susceptibility of E. coli were also analyzed. On the basis of our results, we conclude that O2- and H2O2 may be involved in antibacterial action of ciprofloxacin. Our findings that glutathione gave protection against other fluoroquinolones and not against nonfluoroquinolone antibiotics imply that reactive oxygen species may have a similar role in the antibacterial action of all these fluoroquinolones and that glutathione-mediated protection is not a general phenomenon but specific to fluoroquinolones. These observations are of significance, as fluoroquinolones are important antibiotics with immense therapeutic value, and the effectiveness of treatment by these drugs may be affected by dietary intake and cellular levels of these antioxidants.

[Is the seric eosinophil cationic protein level a valuable tool of diagnosis in clinical practice?]

SCOPE

The eosinophil cationic protein (ECP) is one of the mediators released during eosinophil activation. These cells are effector cells taking part into the Th2-lymphocyte dependent allergic inflammation. Assaying ECP concentrations in blood and sputum may be useful in evaluating allergic inflammation (asthma and rhinitis). This summary considers the value of measuring ECP levels for the diagnosis of various diseases where an eosinophil-mediated tissue inflammation plays a role.

CURRENT SITUATION AND SALIENT POINTS

Levels of eosinophil cationic protein have been determined in nasal secretions, sputum, gastric secretions, feces and serum. They are increased during seasonal allergic rhinitis and perennial rhinitis, allergic asthma and atopic dermatitis. They are also increased in various gastro-intestinal disorders, some of which are associated with IgE: eosinophil intestinal diseases (esophagitis, gastro-enteritis and colitis), gastro-intestinal food allergy and intestinal parasitoses. Finally, they are increased in non IgE-dependent disorders: non allergic asthma with aspirin intolerance, respiratory infections, sinonasal polyposis, Churg-Strauss disease and idiopathic hyper-eosinophilia (HES) syndrome.

PERSPECTIVES

Assaying serum ECP could help in the diagnosis of several diseases. With parasitic disease the pathogenic progression may be accurately assessed, when serological tests are less indicative. ECP assay may point to non allergic asthma, either Fernand-Widal syndrome or Churg-Strauss disease. As for gastro-intestinal disorders, it indicates an eosinophilic tissue reaction. In the event of isolated hypereosinophilia, ECP assay may clarify whether it is benign or tending towards idiopathic HES. The assay of peroxidase and eosinophil-derived neurotoxin (EDN) should be also considered.