2009
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PublicationArticle Protection of palak (Beta vulgaris L. var Allgreen) plants from ozone injury by ethylenediurea (EDU): Roles of biochemical and physiological variations in alleviating the adverse impacts(Elsevier Ltd, 2009) Supriya Tiwari; Madhoolika AgrawalAmeliorative effects of ethylenediurea (N-[2-(2-oxo-1-imidazolinidyl) ethyl]-N′ phenylurea, abbreviated as EDU) against ozone stress were studied on selected growth, biochemical, physiological and yield characteristics of palak (Beta vulgaris L. var Allgreen) plants grown in field at a suburban site of Varanasi, India. Mean eight hourly ozone concentration varied from 52 to 73 ppb which was found to produce adverse impacts on plant functioning and growth characteristics. The palak plants were treated with 300 ppm EDU at 10 days after germination at 10 days interval up to the plant maturity. Lipid peroxidation in EDU treated plants declined significantly as compared to non-EDU treated ones. Significant increment in Fv/Fm ratio in EDU treated plants as compared to non-EDU treated ones was recorded. EDU treated plants showed significant increment in ascorbic acid contents and reduction in peroxidase activity as compared to non-EDU treated ones. As a result of the protection provided by EDU against ozone induced stress on biochemical and physiological characteristics of palak, the morphological parameters also responded positively. Significant increments were recorded in shoot length, number of leaves plant-1, leaf area and root and shoot biomass of EDU treated plants as compared to non-EDU treated ones. Contents of Na, K, Ca, Mg and Fe were higher in EDU treated plants as compared to non-EDU treated ones. The present investigation proves the usefulness of EDU in partially ameliorating ozone injury in ambient conditions. © 2009 Elsevier Ltd. All rights reserved.PublicationArticle Evaluation of physiological, growth and yield responses of a tropical oil crop (Brassica campestris L. var. Kranti) under ambient ozone pollution at varying NPK levels(2009) Poonam Singh; Madhoolika Agrawal; Shashi Bhushan AgrawalA field study was conducted to evaluate the impact of ambient ozone on mustard (Brassica campestris L. var. Kranti) plants grown under recommended and 1.5 times recommended NPK doses at a rural site of India using filtered (FCs) and non-filtered open top chambers (NFCs). Ambient mean O3 concentration varied from 41.65 to 54.2 ppb during the experiment. Plants growing in FCs showed higher photosynthetic rate at both NPK levels, but higher stomatal conductance only at recommended NPK. There were improvements in growth parameters and biomass of plants in FCs as compared to NFCs at both NPK levels with higher increments at 1.5 times recommended. Seed yield and harvest index decreased significantly only at recommended NPK in NFCs. Seed quality in terms of nutrients, protein and oil contents reduced in NFCs at recommended NPK. The application of 1.5 times recommended NPK provided protection against yield loss due to ambient O3. © 2008 Elsevier Ltd. All rights reserved.PublicationArticle Heavy metals in vegetables collected from production and market sites of a tropical urban area of India(2009) Rajesh Kumar Sharma; Madhoolika Agrawal; Fiona M MarshallVegetables (Beta vulgaris L., Abelmoschus esculentus L. and Brassica oleracea L.) from the production and market sites of India were tested for Cu, Cd, Zn and Pb. At market sites, the mean concentration of Cu in cauliflower, and of Zn and Cd in both palak and cauliflower had exceeded the PFA standard. Zn at the production sites also exceeded the PFA standard in cauliflower. Cd concentration in vegetables tested from both production and market sites was many folds higher than the EU standard. In contrast, Pb in vegetables tested from both production and market sites was below the PFA limit, but was considerably higher than the current EU and WHO standards. Heavy metals accumulation in vegetables tested are higher at market sites than those at the crop production sites. The contributions of these vegetables to dietary intake of Cu, Zn, Cd and Pb were 13%, 1%, 47% and 9% of provisional tolerable daily intake, respectively. The study concludes that the transportation and marketing systems of vegetables play a significant role in elevating the contaminant levels of heavy metals which may pose a threat to the quality of the vegetables with consequences for the health of the consumers of locally produced foodstuffs. © 2008 Elsevier Ltd. All rights reserved.PublicationArticle Modification of growth and yield responses of Amaranthus tricolor L. to sUV-B under varying mineral nutrient supply(2009) Suruchi Singh; Rima Kumari; Madhoolika Agrawal; Shashi Bhushan AgrawalThe decrease in stratospheric ozone has heightened concern over the consequences of increasing solar UV-B radiation on plants. The present study was conducted to evaluate the interactive effects of supplemental UV-B (sUV-B: 280-320 nm) and mineral nutrients on a leafy vegetable amaranthus (Amaranthus tricolor L. var Pusa badi) under natural field conditions in a dry tropical environment. The nutrient treatments were recommended dose of NPK, 1.5 times recommended dose of NPK, 1.5 times recommended dose of N and 1.5 times recommended dose of K sUV-B radiation inhibited growth and biomass accumulation and altered the patterns of biomass partitioning. In K amended plants larger proportion of biomass has been translocated to roots which further increased under sUV-B treatment. The application of 1.5 times recommended dose of NPK reduced the magnitude of yield loss. The study shows that amaranthus is a potentially UV-B sensitive species and a higher NPK dose above the recommended is required to minimize the adverse impact of sUV-B. © 2008 Elsevier B.V. All rights reserved.PublicationArticle Real time PCR for the rapid detection of vanA gene in surface waters and aquatic macrophyte by molecular beacon probe(2009) Pushpa Lata; Siya Ram; Madhoolika Agrawal; Rishi ShankerEnterococci serve as an "indicator" of fecal contamination for recreational water quality. The vancomycin-resistant-enterococci (VRE) are emerging environmental contaminants in the surface waters. The aim of this study was to develop a rapid and specific molecular beacon probe (MBP)-based real-time PCR assay for detection of vanA gene in surface waters and aquatic macrophyte. The limit of detection (LOD) of the MBP assay was 1 CFU/mL of VRE [r ) 0.943; PCR efficiency ) 99.7%] in 2-fold dilution format within 2.5 h and demonstrated high specificity for environmental enterococci isolates exhibiting VanA phenotype (n ) 25). VRE were detected from downstream surface waters of the rivers impacted by point sources of pollution andrecreationalactivities. TheprobedetectedvanA geneinroot-mat associated microbiota of E. crassipes (Mart.) Solms. an aquatic nuisance weed, at eutrophic sites of the surface waters(ANOVA p < 0.001).Inaddition,theassayenableddetection of otherwise nondetectable vanA gene concentration in the upstream sites of two Indian rivers (Student's t test p < 0.001). The MBP assay developed can be used for sensitive and rapid detection of VRE in surface waters and identification of nonpoint sources of pollution for implementation of preventive measures to protect human health. © 2009 American Chemical Society.PublicationArticle Differential protection of ethylenediurea (EDU) against ambient ozone for five cultivars of tropical wheat(2009) Shalini Singh; S.B. Agrawal; Madhoolika AgrawalThe antiozonant EDU (ethylenediurea) was used to assess the impact of ambient O 3 under field conditions on five cultivars of tropical wheat (Triticum aestivum L.). EDU solution (0 ppm and 400 ppm) was applied as soil drench (100 ml plant -1) 10 days after germination (DAG) at an interval of 12 days. EDU-treated plants showed significant increments in stomatal conductance, photosynthetic rate, variable fluorescence, total chlorophyll, ascorbic acid, proline and protein contents and protective enzymes (POX, SOD and APX) activities in HUW468, HUW510 and HUW234 cultivars, while, a reverse trend was observed for lipid peroxidation. EDU application restored grain yield significantly by maintaining higher levels of antioxidants, metabolites and enzymes in cultivars HUW468 and HUW510. Sonalika and PBW343 showed least response of measured parameters under EDU treatment suggesting their greater resistance to O 3. EDU, thus proved its usefulness in screening suitable wheat cultivars for areas experiencing elevated concentrations of O 3. © 2009 Elsevier Ltd. All rights reserved.PublicationArticle Enterococci in river Ganga surface waters: Propensity of species distribution, dissemination of antimicrobial-resistance and virulence-markers among species along landscape(2009) Pushpa Lata; Siya Ram; Madhoolika Agrawal; Rishi ShankerBackground. Surface waters quality has declined in developing countries due to rapid industrialization and population growth. The microbiological quality of river Ganga, a life-sustaining surface water resource for large population of northern India, is adversely affected by several point and non-point sources of pollution. Further, untreated surface waters are consumed for drinking and various household tasks in India making the public vulnerable to water-borne diseases and outbreaks. Enterococci, the 'indicator' of water quality, correlates best with the incidence of gastrointestinal diseases as well as prevalence of other pathogenic microorganisms. Therefore, this study aims to determine the distribution of species diversity, dissemination of antimicrobial-resistance and virulence-markers in enterococci with respect to rural-urban landscape along river Ganga in northern India. Results. Enterococci density (χ2: 1900, df: 1; p < 0.0001) increased from up-to-down gradient sites in the landscape. Species diversity exhibit significant (χ2: 100.4, df: 20; p < 0.0001) and progressive distribution of E. faecalis, E. faecium, E. durans and E. hirae down the gradient. Statistically discernible (p: 0.0156 - < 0.0001) background pool of resistance and virulence was observed among different Enterococcus spp. recovered from five sites in the up-to-down gradient landscape. A significant correlation was observed in the distribution of multiple-antimicrobial- resistance (viz., erythromycin-rifampicin-gentamicin-methicillin and vancomycin-gentamicin-streptomycin; rs: 0.9747; p: 0.0083) and multiple-virulence-markers (viz., gelE+esp+; r s: 0.9747; p: 0.0083; gelE+efaA+; r s: 0.8944; p: 0.0417) among different Enterococcus spp. Conclusion. Our observations show prevalence of multiple-antimicrobial-resistance as well as multiple-virulence traits among different Enterococcus spp. The observed high background pool of resistance and virulence in enterococci in river waters of populous countries has the potential to disseminate more alarming antimicrobial-resistant pathogenic bacteria of same or other lineage in the environment. Therefore, the presence of elevated levels of virulent enterococci with emerging vancomycin resistance in surface waters poses serious health risk in developing countries like India. © 2009 Lata et al; licensee BioMed Central Ltd.PublicationArticle Effects of wastewater irrigation on physicochemical properties of soil and availability of heavy metals in soil and vegetables(2009) Anita Singh; Rajesh K. Sharma; Madhoolika Agrawal; F. MarshallThe present study investigated the impact of irrigation with wastewater on nutritional property and heavy-metal concentrations in the soil and consequent accumulation in vegetables at sites having long-term uses of wastewater for irrigation. Samples of irrigation water, soil, and root and shoot parts of palak plants were analyzed to determine the concentration of heavy metals. Wastewater irrigation led to increases in the total and phytoavailable heavy-metal concentrations in the soil at all the sites. Heavy-metal concentrations in soil under wastewater irrigation were negatively and positively correlated with soil hydrogen potential (pH) and organic carbon (OC), respectively. The enrichment factor and metal pollution index were higher at wastewater-irrigated sites as compared to the clean water-irrigated ones. The study concludes that wastewater irrigation modified the physicochemical properties of the soil, leading to more availability of heavy metals in the soil and consequently to the plant. © Taylor & Francis Group, LLC.PublicationReview Chapter 3 Ultraviolet-B Induced Changes in Gene Expression and Antioxidants in Plants(2009) S.B. Agrawal; Suruchi Singh; Madhoolika AgrawalThe depletion of the stratospheric ozone layer leads to an increase in the level of ultraviolet-B radiations reaching the Earth's surface. UV-B radiations are known to have damaging effects on all forms of life. In plants, the UV-B exposure leads to the generation of reactive oxygen species (ROS), eventually resulting in oxidative stress. ROS induce lipid peroxidation of biological membranes, destroy the natural lipid-soluble antioxidants, and alter the expression of several genes through nonspecific signaling pathways. The integration of the thylakoid membrane appears to be much more sensitive than the activities of the photosynthetic components bound within. However, the decrease of mRNA transcripts in the photosynthetic complexes and other chloroplast proteins are among the early events of UV-B damage. Other genes, encoding defense-related proteins are rapidly upregulated under UV-B irradiation. UV-B radiation induced production of ROS, increased the antioxidant capacity and thus, minimized the magnitude of negative impact of UV-B on plants. Specific signaling pathway includes the UVR8 component that regulates the expression of a set of genes essential for the protection of plant against UV-B. This chapter comprises information regarding the UV-B perception, signal transduction, regulation of gene expression, ROS formation, and its metabolism from various studies performed under growth chamber, green house, and field conditions. © 2009 Elsevier Ltd. All rights reserved.