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1.
Sci Total Environ ; 650(Pt 2): 1759-1770, 2019 Feb 10.
Article in English | MEDLINE | ID: mdl-30278420

ABSTRACT

Pervious pavement systems can have a life span of about 20years but, at end-of-life, it becomes necessary to evaluate the state of the infrastructure to determine whether they pose a health and safety risk to workers during dismantling, and also determine potential reuse of the waste material generated. In this paper, we report of an investigation conducted to evaluate whether Pervious pavement systems are hazardous to human health at end-of-life and also to assess the mobility of the stormwater pollutants trapped in the system as a measure of their potential release to receiving systems such as water-bodies and groundwater systems. After decommissioning, the pervious pavement structure was sampled for analysis including Gas Chromatography, inductively coupled plasma spectroscopy and, leachate analysis. Results show that carcinogenic risks were significantly below the regulatory limit of 1×10-6 while, the hazard quotients and cumulative hazard indices were also below regulatory value of 1, based on United States Environmental Protection Agency standards. Furthermore, mean concentrations of benzene, toluene, ethylbenzene and xylene were significantly less than the UK soil guideline values. The results of the leachate analysis show that the metals of concern, Pb, Zn, Cr, Ni, Cd and Cu were all below the threshold for reuse applications such as irrigation purposes as they were all below the regulatory limits such as Food and Agriculture Organization and, United States Environmental Protection Agency standards. Finally, the evaluation of potential reuse and recycling purposes indicate that wastes generated from the dismantling of the PPS are within limits for recycling as aggregates for other civil engineering projects as per European Union standards. This has potential to enhance UK's drive to achieve the target of 70% level of construction & demolition waste recovery for reuse and recycling by the year 2020 as per European Union Water Framework Directive.


Subject(s)
Construction Materials/toxicity , Environmental Monitoring , Recycling , Soil Pollutants/analysis , Water Pollutants, Chemical/analysis , Humans , Rain , Risk Assessment , United Kingdom
2.
Environ Sci Pollut Res Int ; 23(16): 15970-82, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27146530

ABSTRACT

The suitability of stormwater harvested from pervious pavement system (PPS) structures for reuse purposes was investigated in conditions where glyphosate-containing herbicides (GCH) are applied as part of PPS maintenance procedure. The experiment was based on the four-layered design previously described as detailed in CIRIA C582. Results indicated that the highest sodium absorption ratio (SAR) of 1.6 recorded in this study, was less than that at which loss of permeability begins to occur as well as deterioration of matrix structure. Furthermore, the maximum electrical conductivity (ECw) of 2990 µS cm(-1), recorded for 7200 mg L(-1) concentration (GCH) was slightly below the unstable classification range at which salinity problems related to water quality occur such that salts accumulate in the root zone to the extent that crop yields are adversely affected. However, GCH concentration of 720 mg L(-1) was within 'permissible' range while that of 72 mg L(-1) was within 'excellent' range. Current study raises some environmental concerns owing to the overall impact that GCH at concentrations above 72 mg L(-1) exerts on the net performance of the organic decomposers, heavy metal and hydrocarbon release from the system and thus, should be further investigated. However, effluent from all the test models including those dosed with high GCH concentration of 7200 mg L(-1) do not pose any threat in terms of infiltration or deterioration associated with salinity although, there are indications that high dosage of the herbicide could lead to an elevated electrical conductivity of the recycled water. Graphical abstract Impact of herbicide on irrigation water quality.


Subject(s)
Environmental Monitoring , Herbicides/analysis , Recycling , Wastewater/chemistry , Water Pollutants, Chemical/analysis , Water Supply/statistics & numerical data , Glycine/analogs & derivatives , Hydrocarbons/analysis , Metals, Heavy/analysis , Salinity , Water Quality , Glyphosate
3.
Chemosphere ; 100: 34-41, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24462083

ABSTRACT

Pervious Pavement Systems are Sustainable Drainage devices that meet the three-fold SUDS functions of stormwater quantity reduction, quality improvement and amenity benefits. This paper reports on a study to determine the impact of different concentrations of glyphosate-containing herbicides on non-target microorganisms and on the pollutant retention performance of PPS. The experiment was conducted using 0.0484 m(2) test rigs based on a four-layered design. Previous studies have shown that PPS can trap up to 98.7% of applied hydrocarbons, but results of this study show that application of glyphosate-containing herbicides affected this capability as 15%, 9% and 5% of added hydrocarbons were released by high (7200 mg L(-1)), medium (720 mg L(-1)) and low (72 mg L(-1)) glyphosate-containing herbicides concentrations respectively. The concentrations of nutrients released also indicate a potential for eutrophication if these effluents were to infiltrate into aquifers or be released into surface waters. The effect of glyphosate-containing herbicides application on the bacterial and fungal communities was slightly different; fungi exhibited a "top-down" trend as doses of 7200 mg L(-1) glyphosate-containing herbicides yielded the highest fungal growth whilst those with a concentration of 720 mg L(-1) glyphosate-containing herbicides applied yielded the highest bacterial growth. In the case of protists, doses of glyphosate-containing herbicides above 72 mg L(-1) were fatal, but they survived at the lower concentration, especially the ciliates Colpoda cucullus and Colpoda steinii thus indicating potential for their use as biomarkers of herbicide-polluted environments. Data also showed that at the lowest concentration of glyphosate-containing herbicides (72 mg L(-1)), biodegradation processes may not be affected as all trophic levels required for optimum biodegradation of contaminants were present.


Subject(s)
Bacteria/drug effects , Conservation of Natural Resources , Drainage, Sanitary/methods , Environmental Pollutants/toxicity , Fungi/drug effects , Glycine/analogs & derivatives , Herbicides/toxicity , Bacteria/metabolism , Biodegradation, Environmental , Carbon Dioxide/chemistry , Ciliophora/drug effects , Dose-Response Relationship, Drug , Environmental Pollutants/chemistry , Environmental Pollutants/metabolism , Fungi/metabolism , Glycine/chemistry , Glycine/metabolism , Glycine/toxicity , Herbicides/chemistry , Herbicides/metabolism , Hydrocarbons/analysis , Hydrogen-Ion Concentration , Time Factors , Glyphosate
4.
Chemosphere ; 90(2): 737-46, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23098583

ABSTRACT

An experimental investigation was carried out to determine the effect of glyphosate-containing herbicides (GCHs) on the hydrocarbon retention and biodegradation processes known to occur in pervious pavement systems (PPSs). The PPS test rigs were based on the four-layered design detailed in CIRIA C582. This enabled the pollutant retention capacity of the PPS and biodegradation of retained pollutants by microorganisms to be investigated. The use of test rigs also enabled the impact of GCH on PPS eukaryotic organisms to be studied, by the monitoring of protist bioindicators. Results showed that GCH disrupted hydrocarbon retention by the geotextiles relative to rigs with mineral oil only added, as 9.3% and 24.5% of added hydrocarbon were found in herbicide only rigs and herbicide plus oil rigs respectively. In previous studies, PPS contaminated by mineral oil had been shown to retain 98.7% of added oils and over several weeks, biodegrade this oil in situ. Where GCH was added to experimental models, much higher concentrations of heavy metals, including Pb, Cu, and Zn, were released from the PPS in effluent, particularly where GCH and mineral oil were added together. The source of the majority of the metal contamination was thought to be the used engine oil. The herbicide generally increased the total activity of microbial communities in rig systems and had a stimulating effect on bacterial and fungal population numbers. Although the protists, which are part of the microbial community directly or indirectly responsible for biodegradation, were initially strongly affected by the herbicide, they showed resilience by quickly recovering and increasing their population compared with rigs without added herbicide, including the rigs with mineral oil added to them. However, the presence of herbicide was associated with a decrease in the species richness of recorded protist taxa and a predominance of robust, cosmopolitan or ubiquitous protist genera.


Subject(s)
Drainage, Sanitary/methods , Glycine/analogs & derivatives , Herbicides/toxicity , Bacteria/drug effects , Biodegradation, Environmental/drug effects , Fungi/drug effects , Glycine/toxicity , Models, Chemical , Petroleum Pollution , Soil Microbiology , Glyphosate
5.
Cell Mol Biol (Noisy-le-grand) ; 59 Suppl: OL1906-17, 2013 Dec 31.
Article in English | MEDLINE | ID: mdl-24461331

ABSTRACT

Acute toxicity of Roundup, a commercial glyphosate--based herbicide, was evaluated in a teleost marine fish, the European sea bass, after 96 h of exposure. The LC50 96-h value of Roundup was 529 mg/L. Juveniles (Dicentrarchus labrax L.) were exposed to a sublethal concentration (35% of the LC50, i.e. 193 mg/L) of Roundup for 96-h. The study of heme oxygenase-1 (ho-1) gene expression was performed in four tissues (liver, gills, brain and gonads) and highlighted the disruption of antioxidant defence system. Results showed that ho-1 mRNA levels in liver and gills significantly decreased (p<0.001 and p<0.01 respectively) in fish exposed to 193 mg/L of Roundup, whereas in brain and gonads, ho-1 mRNA level was not altered. The analysis of acetylcholinesterase expression was used to evaluate the overall neurotoxicity of the herbicide and aromatase genes to assess the alteration of the endocrine system. Results showed that AChE and cyp19b gene transcriptions significantly increased (p<0.01) in brain of sea bass, whereas aromatase gene expression (cyp19a) in gonads was not significantly altered. Our results showed complex tissue-specific transcriptional responses after 96 h of exposure to a sublethal concentration. All these disruptions confirmed the deleterious effects of this glyphosate-based herbicide in a marine species.


Subject(s)
Acetylcholinesterase/metabolism , Aromatase/metabolism , Bass/metabolism , Gene Expression Regulation, Enzymologic/drug effects , Glycine/analogs & derivatives , Heme Oxygenase-1/metabolism , Herbicides/toxicity , Acetylcholinesterase/genetics , Animals , Aromatase/genetics , Bass/growth & development , Behavior, Animal/drug effects , Brain/metabolism , Europe , Gills/metabolism , Glycine/toxicity , Gonads/metabolism , Heme Oxygenase-1/genetics , Liver/metabolism , RNA, Messenger/metabolism , Glyphosate
6.
Cell Mol Biol (Noisy-le-grand) ; Suppl.58: OL1752-6, 2012 Sep 17.
Article in English | MEDLINE | ID: mdl-22992441

ABSTRACT

One of the most pertinent environmental factors influencing the marine organism life is temperature. It has been demonstrated that an increase of temperature is able to induce the synthesis of heat shock proteins (HSP). In this study we investigated the expression of HO-1 mRNA, also referred to as HSP32, in different tissues of European sea bass (Dicentrarchus labrax, L.) at several time points after increased temperature exposure (from 12degC to 30degC). Our results showed that HO-1 was not expressed in gills, heart, muscle and brain while it was expressed at a basal level in intestine. In liver, spleen and kidneys, HO-1 expression was influenced by temperature increases. In the spleen, we found a significant decrease of the HO-1 expression at the end of 4 weeks. In kidneys a very fast collapse of HO-1 expression level was recorded reaching null value as soon as one hour after exposure to 30degC. In liver, HO-1 expression increased from one hour of exposure to 30degC confirming HO-1 involvement to heat shock response in this organ. This increasing trend reached a 4.5-fold higher value than the initial level after 4 weeks.


Subject(s)
Bass/metabolism , Heme Oxygenase-1/metabolism , Water/chemistry , Animals , Heme Oxygenase-1/genetics , Intestinal Mucosa/metabolism , Kidney/metabolism , Liver/metabolism , RNA, Messenger/metabolism , Spleen/metabolism , Temperature
7.
Cell Mol Biol (Noisy-le-grand) ; 57 Suppl: OL1614-22, 2011 Oct 28.
Article in English | MEDLINE | ID: mdl-22047796

ABSTRACT

It has been previously demonstrated that "Warm temperature Acclimation-related 65 kD Protein" (WAP65) is involved in temperature acclimation, response to intoxication and infection, as well as in development. The expression of wap65-1 was investigated in the liver of European sea bass (Dicentrarchus labrax) during exposure to the increased temperature (from 12 deg C to 30 deg C) and during intoxication with four heavy metals: lead, cadmium, copper and zinc. Post temperature increase wap65 expression was highest after one hour at 30 deg C. After 1 to 4 weeks at 30 deg C wap65 transcript levels did not differ from the 12 deg C control group, similar to observations regarding the heat shock protein, hsp70. Upregulation of wap65 was detected after treatment (intoxication) with cadmium (0.5 µg/l). In contrast, a slight, but significant down regulation of wap65 was seen after copper (5 µg/l) intoxication. These data indicate that functional analyses of WAP65 are needed to understand the differential regulation of this gene by metals. The role of WAP65 may be similar to that of HSP70, which has generalized functions in responding to certain stressors and maintaining normal cell physiology.


Subject(s)
Bass/genetics , Fish Proteins/genetics , Liver/metabolism , Metals, Heavy/metabolism , Animals , Gene Expression Regulation , Temperature
8.
Water Sci Technol ; 62(3): 615-21, 2010.
Article in English | MEDLINE | ID: mdl-20706008

ABSTRACT

Pervious pavements are drainage techniques that improve urban water management in a sustainable manner. An experimental pervious pavement parking area has been constructed in the north of Spain (Santander), with the aim of harvesting good quality rainwater. Forty-five pervious pavement structures have been designed and constructed to measure stored water quantity and quality simultaneously. Ten of these structures are specifically constructed with different geotextile layers for improving water storage within the pavements. Following the confirmation in previous laboratory experiments that the geotextile influenced on water storage, two different geosynthetics (Inbitex and a One Way evaporation control membrane) and control pervious pavements with no geotextile layers were tested in the field. Weather conditions were monitored in order to find correlations with the water storage within the pervious pavement models tested. During one year of monitoring the three different pervious pavement types tested remained at their maximum storage capacity. The heavy rain events which occurred during the experimental period caused evaporation rates within the pervious pavements to be not significant, but allowed the researchers to observe certain trends in the water storage. Temperature was the most closely correlated weather factor with the level of the water stored within the pervious pavements tested.


Subject(s)
Conservation of Natural Resources/methods , Construction Materials , Rain , Spain , Time Factors , Transportation , Water
9.
Comp Biochem Physiol B Biochem Mol Biol ; 155(4): 396-402, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20085823

ABSTRACT

The complementary DNA encoding WAP65 protein was cloned from the liver of two fish species sea bass (Dicentrarchus labrax) and sea bream (Sparus aurata). Full-length cDNA sequences were obtained from reverse transcribed total RNA, followed by 5' and 3' rapid amplification of cDNA end (RACE) experiments. The full-length cDNA sequence of D. labrax is 1709bp and the coding sequence is flanked by a 67bp 5'-UTR and a 358bp 3'-UTR. The full-length cDNA sequence of S. aurata is 1599bp, and the coding sequence is flanked by a 48bp 5'-UTR and a 273bp 3'-UTR. The deduced amino acid putative primary sequences are composed of 427 and 425 amino acid residues for D. labrax and S. aurata, respectively. They display high homologies with previously described fish WAP65 and other hemopexin-like proteins from rabbit (Oryctolagus cuniculus). Expression of Wap65 has proved to be a natural physiological adaptive answer of teleost fish to warm temperature acclimation. In all fish species studied to date, Wap65 was found expressed mainly by the liver, although other tissues seem able to express Wap65 in response to a warm temperature acclimation, in a specie specific manner. Here, we investigate the tissue specific expression of Wap65 in D. labrax and S. aurata in response to a warm temperature acclimation, by RT-PCR analysis.


Subject(s)
Bass/genetics , Fish Proteins/genetics , Sea Bream/genetics , Amino Acid Sequence , Animals , Cloning, Molecular , Molecular Sequence Data , Phylogeny , Reverse Transcriptase Polymerase Chain Reaction , Sequence Alignment , Species Specificity , Temperature
10.
J Clin Microbiol ; 45(4): 1205-10, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17287330

ABSTRACT

We prospectively evaluated a new PCR-enzyme-linked immunosorbent assay kit (Onychodiag; BioAdvance, France) for the diagnosis of dermatophytic onychomycosis by testing nail samples from 438 patients with suspected onychomycosis and from 108 healthy controls in three independent laboratories. In two laboratories, samples were collected by trained mycologists as close as possible to the lesions (proximal samples). In one laboratory, samples were collected by other physicians. All samples were processed by conventional mycological techniques and by Onychodiag, blindly to the mycological results. An additional distal sample, collected by clipping the nail plate, was obtained from 75 patients and tested with Onychodiag alone. In patients with culture-proven dermatophytic onychomycosis, the sensitivity of Onychodiag was 83.6% (87.9% including the gray zone) and ranged from 75 to 100% according to the laboratory and the sampling conditions. The specificity was 100% when healthy subjects were considered true negative controls. Onychodiag was positive on 68 patient samples that were sterile or yielded nondermatophyte species in culture. Based on the results of Onychodiag for mycologically proven positive samples and true-negative samples, these results were considered true positives, and the poor performance of mycology on these samples was attributed to inconvenient sampling conditions or to contaminants. When tested on distal samples, Onychodiag was positive in 49/53 (92%) cases of proven dermatophytic onychomycosis. Finally, with either proximal or distal samples, Onychodiag provided a diagnosis of dermatophytic onychomycosis within 24 to 48 h after sampling, and its sensitivity was close to that of mycological techniques applied to proximal samples.


Subject(s)
Enzyme-Linked Immunosorbent Assay/methods , Microsporum/isolation & purification , Molecular Diagnostic Techniques/methods , Onychomycosis/diagnosis , Polymerase Chain Reaction/methods , Trichophyton/isolation & purification , Humans , Microsporum/genetics , Nails/microbiology , Onychomycosis/microbiology , Prospective Studies , Reagent Kits, Diagnostic , Sensitivity and Specificity , Trichophyton/genetics
11.
Water Sci Technol ; 54(6-7): 273-80, 2006.
Article in English | MEDLINE | ID: mdl-17120659

ABSTRACT

The development of a self-fertilising geotextile mat designed to provide a sustained slow-release of required inorganic nutrients for the growth of oil degrading microorganisms in porous pavement systems (PPS) is reported. The system comprises a geotextile spun from polymer fibres containing spherical phosphated polymer beads that release phosphate upon contact with water at a desirable level for microbial growth. Initial results using model PPS have shown that the self-fertilising geotextile system works extremely effectively as increased microbial activity has been observed throughout the experiment, illustrating that the oil-degrading bacteria can effectively utilise this polymer composite as a suitable nutrient source.


Subject(s)
Bacteria/metabolism , Fuel Oils , Phosphates/chemistry , Polymers/chemistry , Water Pollutants, Chemical/metabolism , Bacteria/growth & development , Biodegradation, Environmental , Permeability , Phosphates/metabolism , Rain
12.
J Exp Bot ; 57(2): 329-41, 2006.
Article in English | MEDLINE | ID: mdl-16330523

ABSTRACT

Light intensity and atmospheric CO2 partial pressure are two environmental signals known to regulate stomatal numbers. It has previously been shown that if a mature Arabidopsis leaf is supplied with either elevated CO2 (750 ppm instead of ambient at 370 ppm) or reduced light levels (50 micromol m-2 s-1 instead of 250 micromol m-2 s-1), the young, developing leaves that are not receiving the treatment grow with a stomatal density as if they were exposed to the treatment. But the signal(s) that it is believed is generated in the mature leaves and transmitted to developing leaves are largely unknown. Photosynthetic rates of treated, mature Arabidopsis leaves increased in elevated CO2 and decreased when shaded, as would be expected. Similarly, the levels of sugars (glucose, fructose, and sucrose) in the treated mature leaves increased in elevated CO2 and decreased with shade treatment. The levels of sugar in developing leaves were also measured and it was found that they mirrored this result even though they were not receiving the shade or elevated CO2 treatment. To investigate the effect of these treatments on global gene expression patterns, transcriptomics analysis was carried out using Affymetrix, 22K, and ATH1 arrays. Total RNA was extracted from the developing leaves after the mature leaves had received either the ambient control treatment, the elevated CO2 treatment, or the shade treatment, or both elevated CO2 and shade treatments for 2, 4, 12, 24, 48, or 96 h. The experiment was replicated four times. Two other experiments were also conducted, one to compare and contrast gene expression in response to plants grown at elevated CO2 and the other to look at the effect of these treatments on the mature leaf. The data were analysed and 915 genes from the untreated, signalled leaves were identified as having expression levels affected by the shade treatment. These genes were then compared with those whose transcript abundance was affected by the shade treatment in the mature treated leaves (1181 genes) and with 220 putative 'stomatal signalling' genes previously identified from studies of the yoda mutant. The results of these experiments and how they relate to environmental signalling are discussed, as well as possible mechanisms for systemic signalling.


Subject(s)
Acclimatization , Arabidopsis/metabolism , Carbon Dioxide/pharmacology , Light , Signal Transduction , Arabidopsis/anatomy & histology , Arabidopsis/drug effects , Arabidopsis Proteins/classification , Arabidopsis Proteins/genetics , Carbohydrate Metabolism , Chlorophyll/analysis , Diffusion , Environment , Gene Expression Regulation, Plant , Genes, Plant/physiology , Oligonucleotide Array Sequence Analysis , Photosynthesis , Plant Leaves/drug effects , Plant Leaves/growth & development , Plant Leaves/metabolism , RNA, Plant/metabolism
13.
Plant Mol Biol ; 57(5): 645-57, 2005 Mar.
Article in English | MEDLINE | ID: mdl-15988561

ABSTRACT

An aleurain-like protein, BoCP5, is up-regulated during harvest-induced senescence in broccoli floret and leaf tissue. BoCP5 is most closely related to an Arabidopsis protein (91%, AAF43041) and has 71% identity to barley aleurain (P05167). The mRNA for this gene accumulates within 6 h after harvest in broccoli florets, and its expression is reduced in tissue that has been held in senescence-delaying treatments (e.g. water, sucrose feeding, controlled atmosphere). The gene is also expressed in leaves during aging-related and harvest-induced senescence. Analysis of protein bands that cross-react with antibodies raised to the bacterial BoCP5 fusion protein, revealed prominent immunoreactive bands at ca. 26, 28, 31, and 38 kD in floret tissue. The 31 kD band was absent in protein extracts from leaf tissue. Agrobacterium-mediated transformation was used to produce transgenic broccoli plants with down-regulated BoCP5. A reduction in the postharvest expression of BoCP5 in floret tissue was achieved for four transgenic lines in the current study. In three of these lines postharvest floret senescence (yellowing) was delayed, and florets contained significantly greater chlorophyll levels during postharvest storage at 20 degrees C than wild-type plants. Line 4 showed the greatest down-regulation of BoCP5, and in this line postharvest protease activity remained at pre-harvest levels, and the yield of soluble proteins extracted from florets after harvest was significantly greater than that of wild-type tissue.


Subject(s)
Brassica/genetics , Cysteine Endopeptidases/genetics , Flowers/genetics , Amino Acid Sequence , Blotting, Western , Brassica/enzymology , Brassica/physiology , Cysteine Endopeptidases/metabolism , DNA, Antisense/genetics , DNA, Complementary/chemistry , DNA, Complementary/genetics , DNA, Complementary/isolation & purification , Flowers/enzymology , Flowers/physiology , Gene Expression Regulation, Developmental , Gene Expression Regulation, Enzymologic , Gene Expression Regulation, Plant , Molecular Sequence Data , Plants, Genetically Modified , RNA, Messenger/genetics , RNA, Messenger/metabolism , Sequence Alignment , Sequence Analysis, DNA , Sequence Homology, Amino Acid , Time Factors
14.
Water Sci Technol ; 45(7): 51-6, 2002.
Article in English | MEDLINE | ID: mdl-11989892

ABSTRACT

This paper reports on continuing research at Coventry University into the improvement of highway water quality following flow through a permeable pavement. Such pavements have been shown elsewhere to be efficient in-situ bio-reactors, capable of degrading large quantities of clean motor oil. Further laboratory research, reported here, demonstrates that a commercially obtained oil degrading, microbial mixture was not significantly better at degrading clean motor oil than the indigenous microbial biomass established within the pavement over a 4-year period, when provided with an adequate nutrient supply. Scanning electron microscopy has been used to monitor biofilm development, which has also identified that the pavement has developed a complex community structure with high bio-diversity.


Subject(s)
Biofilms , Fuel Oils , Water Pollutants, Chemical/metabolism , Biodegradation, Environmental , Biomass , Microscopy, Electron, Scanning , Permeability
16.
Plant J ; 11(6): 1207-18, 1997 Jun.
Article in English | MEDLINE | ID: mdl-9225464

ABSTRACT

The E4/E8 binding protein (E4/E8BP) interacts with sequences in the 5' flanking regions of two genes, E4 and E8, that are coordinately regulated by ethylene during tomato fruit ripening. The DNA-binding activity of this protein increases during fruit ripening, and it may play a role in regulation of these genes. To begin to understand the function of this protein, a cDNA has been isolated that encodes a protein, E4/E8BP-1, with DNA-binding specificity similar to that of E4/E8BP. This DNA-binding protein is closely related to a DNA binding protein from tobacco, 3AF1, that interacts with the promoter of the pea rbcS-3A gene. A repeated domain was identified within the predicted 3AF1 amino acid sequence, which includes a series of histidines and cysteines, suggestive of zinc binding, and this repeat is conserved in E4/E8BP-1. Interaction of both E4/E8BP-1 and nuclear extracts from ripening fruit with the E8 recognition sequence is sensitive to 1,10-phenanthroline, indicating that a metal is required for binding of both the native and recombinant proteins. The mRNA for E4/E8BP-1 is moderately abundant in fruit, and increases slightly during fruit ripening, consistent with a role in fruit ripening. A truncated version of E4/E8BP-1 was able to transactivate the E4 promoter in transient assay, demonstrating that this DNA-binding protein can interact with the E4 promoter in vivo to enhance gene transcription.


Subject(s)
DNA-Binding Proteins/genetics , Genes, Plant , Plant Proteins/genetics , Amino Acid Sequence , Base Sequence , Binding Sites , DNA, Plant/metabolism , DNA-Binding Proteins/chemistry , DNA-Binding Proteins/metabolism , Fruit/genetics , Solanum lycopersicum/genetics , Molecular Sequence Data , Plant Proteins/chemistry , Plant Proteins/metabolism , RNA, Messenger/metabolism , Transcriptional Activation
17.
Plant Mol Biol ; 31(6): 1117-27, 1996 Sep.
Article in English | MEDLINE | ID: mdl-8914528

ABSTRACT

E4 gene transcription is controlled by ethylene during tomato fruit ripening. To define the ethylene-responsive promoter elements, we have tested the activity of mutations of the E4 promoter, and of chimeric genes in transient assay. Using a set of linker scan mutations of the region from -160 to -91, we determined that sequences located between -150 and -121 bp from the transcription start site are required for normal levels of ethylene-regulated transcription. However, E4 sequences from -193 to -40 were not able to confer ethylene-responsiveness to the minimal (-46) 35S promoter. The E4/E8 binding protein (E4/E8 BP) interacts with sequences in the 5'-flanking regions of both E4 and the coordinately regulated E8 gene, and its role in regulation of E4 transcription was investigated. The E4 binding site spans the E4 TATA box, and so mutations of this site were limited to those that did not disrupt the E4 TATA box. Mutations of this site which reduced affinity for the E4/E8 BP also resulted in reduced activity in transient assay, supporting a role for this element in normal regulation of the gene. Fusion of the 35S enhancer to E4 sequences from -85 to +65 did not result in an ethylene-responsive promoter, indicating that the E4/E8 BP-binding site is not sufficient for ethylene response. We conclude that at least two cis elements are required for ethylene-responsive transcription of the E4 gene during fruit ripening, one between -150 and -121 and the other between -40 and +65.


Subject(s)
DNA-Binding Proteins , Ethylenes/pharmacology , Gene Expression Regulation, Plant , Plant Growth Regulators/pharmacology , Plant Proteins/genetics , Solanum lycopersicum/genetics , Base Sequence , Binding Sites , DNA Mutational Analysis , Enhancer Elements, Genetic , Solanum lycopersicum/drug effects , Solanum lycopersicum/growth & development , Models, Genetic , Molecular Sequence Data , Mutagenesis, Site-Directed , Plant Proteins/biosynthesis , Promoter Regions, Genetic , Recombinant Fusion Proteins , TATA Box , Transcription, Genetic
18.
Planta ; 197(3): 442-7, 1995.
Article in English | MEDLINE | ID: mdl-8580758

ABSTRACT

A cDNA encoding a metallothionein-like protein has been isolated from a cDNA library from the abscission zones of ethylene-treated Sambucus nigra leaflets. The precise function of this group of proteins in plants has yet to be confirmed but in animals there is convincing evidence that they bind heavy metals. Several of these proteins have recently been characterised from plants and it has been demonstrated that heavy metals have no stimulatory effect on their expression. In this paper we describe the isolation and characterisation of a metallothionein-like mRNA identified as a consequence of differentially screening a cDNA library for messages up-regulated during abscission. The accumulation of the mRNA occurred in the abscission zone tissue within 18 h of exposure to ethylene while, in contrast, no expression was detectable in adjacent non-abscission-zone tissue. The transcript size of the message was approximately 0.6 kb. Northern analysis revealed that the cDNA insert (JET12) did not hybridise to mRNA from either green or senescing leaflets but a signal was detectable with mRNA extracted from senescent tissue. The size of this hybridising transcript was approximately 0.5 kb. The predicted metallothionein-like protein encoded by JET12 was cysteine-rich (18.4%) and had a molecular weight of approximately 7.5 kDa. Southern analysis of S. nigra genomic DNA showed that the mRNA was encoded by a small gene family. The protein exhibited greatest homology to other metallothioneins belonging to the Type 2 family including those from Mimulus (62%) and Arabidopsis (57%). This homology was greatest around the cysteine-rich amino and carboxy termini.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Metallothionein/genetics , Plant Leaves/genetics , Plant Proteins/genetics , RNA, Messenger/genetics , Amino Acid Sequence , Base Sequence , Blotting, Southern , Cloning, Molecular , DNA, Plant , Ethylenes/pharmacology , Metallothionein/metabolism , Molecular Sequence Data , Plant Proteins/metabolism , RNA, Messenger/metabolism , RNA, Plant
19.
Plant Mol Biol ; 24(6): 961-4, 1994 Mar.
Article in English | MEDLINE | ID: mdl-8204832

ABSTRACT

A cDNA library was produced using mRNA extracted from ethylene-treated leaflet abscission zones of common elder (Sambucus nigra). Screening of the library with the insert from pBAC10, which encodes an abscission beta-1,4-glucanase (cellulase) from bean (Phaseolus vulgaris), resulted in the isolation of a near-full-length cDNA which was designated JET 1. Northern analysis, using JET 1 as a probe, detected a transcript of 1.9 kb that accumulated prior to the first visible signs of cell separation. Accumulation of the JET 1 transcript is promoted by ethylene and primarily restricted to the tissue comprising the abscission zone. Sequence analysis of JET 1 indicates it is 1768 bp in length and shares significant homology at the amino acid level with beta-1,4-glucanases from the leaf abscission zone of P. vulgaris (67%) and ripening avocado fruit (48%). The predicted peptide sequence of the S. nigra enzyme contains two potential glycosylation sites. Genomic Southern analysis of S. nigra DNA reveals that JET 1 may belong to a multi-gene family.


Subject(s)
Glycoside Hydrolases/genetics , Plants/genetics , RNA, Messenger/genetics , Amino Acid Sequence , Molecular Sequence Data , Plant Development , Plants/enzymology , RNA, Messenger/metabolism , Sequence Homology, Amino Acid
20.
Plant Mol Biol ; 24(1): 223-7, 1994 Jan.
Article in English | MEDLINE | ID: mdl-8111020

ABSTRACT

Dehiscence of oilseed rape pods, commonly known as pod shatter, is a process of agronomic importance that results in seed loss causing yield reductions and carry-over of the crop into the following growing season. In an effort to understand the mechanisms underlying this developmental event, the changes in gene expression that accompany pod shatter have been examined with a view to understanding how the process is regulated. In order to achieve this, cDNA library was constructed using mRNA extracted from the dehiscence zone of developing pods. Differential screening with non-dehiscence zone cDNA led to the isolation of a pod-specific clone, SAC25, with a transcript size of 1100 nucleotide encoding a predicted polypeptide of 34 kDa. The level of SAC25 mRNA accumulation increased during pod development. The sequence shows no significant homology to others within the databases but has two identifiable amino acid motifs, one is an adenine nucleotide binding site for NAD/FAD dehydrogenases and the other is a conserved feature of the ribitol dehydrogenase family. The amino acid sequence has four putative glycosylation sites and contains four cysteine residues. Genomic Southern analysis indicates that SAC25 may be encoded by a single gene or a small gene family. The function of this mRNA is unknown but possible roles in dehiscence and pod development are discussed.


Subject(s)
Brassica/genetics , Plant Proteins/genetics , Amino Acid Sequence , Base Sequence , Blotting, Northern , Blotting, Southern , Brassica/growth & development , DNA , Molecular Sequence Data , RNA, Messenger/metabolism
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