973 research outputs found

    Salt tolerant wheat landraces and Gly II transformed lines show distinct biochemical mechanisms of stress tolerance

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    The present investigation was carried out to study the distinct salt tolerance mechanism in two sets of material, Gly II transgenics and Kharchia landraces. The Gly II transgenics were developed for glyoxalase II (osglyII) gene (GenBank accession no. AY054407) from Oryza sativa through Agrobacterium mediated method in the background of wheat cultivar PBW 621. Kharchia 65 is a salt tolerant landrace derivative developed from Kharchia local which is native to saline soils of Rajasthan. The six wheat genotypes, viz. Kharchia local, Kharchia 65, PBW 621, G-2-2, G-3-4 and G-1-13 were evaluated for growth parameters, antioxidant enzymes and contents of glutathione, ascorbic acid, malondialdehyde (MDA), H2O2, sugars, chlorophyll, carotenoid, electrolyte leakage (EL) and Na+, K+ under control and two salt treatments (150 mM and 250 mM NaCl). The activities of antioxidant enzymes, glutathione, sugar content increased in both GlyII and Kharchia genotypes as compared to PBW 621. The GlyII activity increased (77–84%) in GlyII genotypes alongwith content of reduced glutathione (GSH) to maintain redox homeostasis. Apparently, GlyII and Kharchia genotypes exhibited minimum oxidative stress due to low content of MDA, H2O2, diminished EL and thereby causing less growth reduction and maintaining high chlorophyll and carotenoid level as compared to PBW 621. In addition, Gly II transgenic material and Kharchia lines showed less Na+ accumulation, greater seedling biomass and sugar content due to its salt tolerance mechanism. We infer that GlyII activity enhances GSH which play significant role in detoxifying ROS to establish stress homeostasis. The route for generation of GSH is via ascorbate-glutathione pathway mediated by glutathione reductase. Hence, GlyII transgenics and Kharchia genotypes can diminish salt stress following above mechanism

    Supplementation of nitrogen and its influence on free sugars, amino acid and protein metabolism in roots and internodes of wheat

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    Effect of different doses of nitrogen (N) (90, 120, 150 and 180 kg Nha–1) on the activities of aminotransferases and alkaline inorganic pyrophosphatase (AIP) in relation to the accumulation of proteins, amino acids and sugars in roots and internodes at 15 and 40 days post anthesis (DPA) stages was studied in six wheat genotypes namely HD 2967, GLU 1101, PBW 343, BW 9022, PH-132-4840 and PBW 550. Supra-optimal N doses (150 kg Nha–1 and 180 kg Nha–1) accentuated glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT) and alkaline inorganic pyrophosphatase activities in correspondence with an increase in amino acid, protein and sugar content in both roots and internodes in all the six genotypes. Activities of analyzed enzymes were significantly high at 15 days post anthesis (DPA) stage and thereafter declined at maturity (40 DPA) in parallel with decrease in amino acid contents. Maximum activity of GOT, GPT and AIP was observed in HD 2967 and GLU 1101 genotypes along with higher build up of proteins and amino acids which resulted in higher grain yield. Activity of GPT was comparatively high over GOT, indicating its major role towards protein synthesis. Grain filling processes in terms of proteins and amino acids were positively correlated with GOT and GPT activities while sugars were correlated to AIP. Thus, nitrogen acquisition and assimilation resulted in favoured utilization of N in form of amino acid and proteins accumulation while sugar content was also stimulated. Due to immense activities of aminotransferases and higher contents of amino acids and proteins in GLU 1101 and HD 2967 genotypes at optimal dose and higher dose of N, these genotypes hold future potential for developing new cultivars with better grain quality characteristics

    Production of ammonia makes Venusian clouds habitable and explains observed cloud-level chemical anomalies.

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    The atmosphere of Venus remains mysterious, with many outstanding chemical connundra. These include the unexpected presence of ∟10 ppm O2 in the cloud layers, an unknown composition of large particles in the lower cloud layers, and hard to explain measured vertical abundance profiles of SO2 and H2O. We propose a hypothesis for the chemistry in the clouds that largely addresses all of the above anomalies. We include ammonia (NH3), a key component that has been tentatively detected both by the Venera 8 and Pioneer Venus probes. NH3 dissolves in some of the sulfuric acid cloud droplets, effectively neutralizing the acid and trapping dissolved SO2 as ammonium sulfite salts. This trapping of SO2 in the clouds, together with the release of SO2 below the clouds as the droplets settle out to higher temperatures, explains the vertical SO2 abundance anomaly. A consequence of the presence of NH3 is that some Venus cloud droplets must be semisolid ammonium salt slurries, with a pH of ∟1, which matches Earth acidophile environments, rather than concentrated sulfuric acid. The source of NH3 is unknown but could involve biological production; if so, then the most energy-efficient NH3-producing reaction also creates O2, explaining the detection of O2 in the cloud layers. Our model therefore predicts that the clouds are more habitable than previously thought, and may be inhabited. Unlike prior atmospheric models, ours does not require forced chemical constraints to match the data. Our hypothesis, guided by existing observations, can be tested by new Venus in situ measurements

    Apical stem culturing to enhance cell sap assimilates towards grain sucrose and glutamine metabolism in wheat

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    Apical stem culturing offers an alternative approach of manipulating cell sap for wheat grain carbon and nitrogen metabolism in a near in vivo conditions. Employing this technique, role of sucrose and glutamine in transport stream on sucrose metabolism, ammonia assimilation and aminotransferase activities were assessed towards starch and protein accumulation in two wheat genotypes PBW 343 (low yield) and PBW 621 (high yield). At mid-milky stage, detached tillers were cultured in complete liquid medium containing varied concentration of glutamine and sucrose for seven days during year 2012–13 and 2013–14. Increasing glutamine concentration from 17 to 25 mM in the culture medium having 117 mM sucrose enhanced activities of nitrate reductase, glutamate synthase, glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT) at 4 days after culturing (DAC) in correspondence with an increase in soluble protein content. However, at 7 DAC content of soluble protein decreased whereas starch accumulation increased showing, thereby a compensatory effect on carbon and nitrogen metabolism. Apparently, activities of sucrose synthase, soluble acid and neutral invertase significantly decreased. Increasing sucrose concentration from 117 to 125mMled to an increase in transformation of sugars to starch in grain but protein content decreased. PBW621 showed high protein content due to higher activities of GOT, GPT at 4 DAC which subsequently increased carbon skeleton of proteins towards starch synthesis at 7 DAC. Grain filling processes in terms of soluble sugars/starch were strongly correlated to invertase activities whereas proteins to aminotransferases

    Analysis of MAGSAT data of the Indian region

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    Progress in the development of software for reading MAGSAT data tapes and for the reduction of anomaly data, and in the preparation of data for magnetic anomaly maps is reported

    Effects of cutouts on the behavior of symmetric composite laminates subjected to bending and twisting loads

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    Composite structures are used for a wide variety of aerospace applications. Practical structures contain cutouts and these structures are subjected to in-plane and out-of-plane loading conditions. Structurally efficient designs for composite structures require a thorough understanding of the effects of cutouts on the response of composite plates subjected to inplane or out-of-plane loadings. Most investigations of the behavior of composite plates with cutouts have considered in-plane loadings only. Out-of-plane loadings suchas bending or twisting have received very limited attention. The response of homogeneous plates (e.g., isotropic or orthotropic plates) subjected to bending or twisting moments has been studied analytically. These analyses are for infinite plates and neglect finite-plate effects. Recently, analytical and experimental studies were conducted to determine the effects of cutouts on the response of laminated composite plates subjected to bending moments. No analytical or experimental results are currently available for the effects of cutouts on the response of composite laminates subjected to twisting moments

    Syringaldazine peroxidase stimulates lignification by enhancing polyamine catabolism in wheat during heat and drought stress

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    Six wheat cultivars, namely PBW 343, PBW 550 (stress susceptible), PBW 621, PBW 175 (drought tolerant), C 306 and HD 2967 (heat tolerant), were used in this study to evaluate the effect of heat and drought stress on the activities of peroxidases (POXs), diamine oxidase (DAO), polyamine oxidase (PAO) and arginine decarboxylase (ADC) and ornithine decarboxylase (ODC) in relation to contents of polyamines (PAs), lipid peroxide and lignin. High temperature (HT) elevated activities of syringaldazine peroxidase (SPX), guaiacol peroxidase (GPX) and coniferyl alcohol peroxidase (CPX) in heat tolerant cultivars while, drought stress accentuated ADC/ODC activities in drought tolerant cultivars. Both heat and drought stress enhanced activities of DAO and PAO alongwith contents of H2O2 in PBW 175 and C 306. Amongst studied POXs, SPX activity was relatively more and coincided well with lignin content under HT stress while, the levels of ADC/ODC paralleled with putrescine and spermidine contents under drought stress. Higher build up of thiobarbituric acid reactive substances in cultivars PBW 343 and PBW 550 indicated their membrane instability during both the stresses. Our results revealed that SPX mediated lignification leading to higher cell wall rigidity under heat stress and drought increased PAs involved in ROS scavenging due to presence of positive charges which can bind strongly to the negative charges in cellular components such as proteins and phospholipids and thereby stabilize the membranes under stress conditions

    ‘I don't think I can catch it’: women, confidence and responsibility in football coach education

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    Whilst women’s participation in sport continues to increase, their presence remains ideologically challenging given the significance of sport for the construction of gendered identities. As a hegmonically masculine institution, leadership roles across sport remain male-dominated and the entry of women into positions of authority (such as coaching) routinely contested. But in powerful male-typed sports, like football, women’s participation remains particularly challenging. Consequently, constructions of gender inequity in coaching were explored at a regional division of the English Football Association through unstructured interviews and coaching course observation. Using critical discourse analysis we identified the consistent re/production of women as unconfident in their own skills and abilities, and the framing of women themselves as responsible for the gendered inequities in football coaching. Women were thereby strategically positioned as deservedly on the periphery of the football category,whilst the organization was positioned as progressive and liberal
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