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Search Results: 1 - 10 of 411128 matches for " Hamdia M. Abd El-Samad "
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The Potential Role of Osmotic Pressure to Exogenous Application of Phytohormones on Crop Plants Grown under Different Osmotic Stress  [PDF]
Hamdia M. Abd El-Samad
American Journal of Plant Sciences (AJPS) , 2016, DOI: 10.4236/ajps.2016.76089
Abstract: The osmotic pressure represented as a sign of plant tolerance or sensitive to salinity stress. In the following plants, the increase in OP seems to be a manner of defense mechanism to survive. OP increased in shoots of maize, shoot and root of wheat and cotton plants was concomitant with shoot soluble sugar, root soluble protein and shoot and root amino acids of maize plants. However, in wheat the increase in OP was related with increase of root soluble sugar and protein of shoots and roots. In cotton plants, the elevation of OP was run parallel with increase soluble sugar of shoots and roots, shoot soluble protein and root amino acids. The increase in OP was related with a marked and significant reduction in the water content of these plants. However, the decrease in OP of shoot and root of broad bean was related with the reduction of shoots and roots soluble sugar, protein and root amino acids of broad bean. While the OP becomes more or less unchanged in shoots and tended to decrease in root of parsley plants, this concomitant with unchanged trend in the shoots amino acids and reduction in root soluble sugar and root amino acids. Run with previous trend values of OP and metabolites of parsley plants were related with stable values in shoot water content and reduction in root water content. With GA3 and kinetin treatments mostly increase the values OP which parallel with increase and soluble sugar, soluble protein and amino acids contents of shoots and roots of maize, wheat, cotton, broad bean and parsley plants with NaCl increasing. This related with increase water uptake by roots in these plants. The results indicated that kinetin had a more effective to shoot maize, both organs of wheat, broad bean and parsley plants in response to salinity stress while GA3 was more effective on cotton plants especially at higher levels of salinity. Thus plants strategy differed in their tolerance to salinity stress according to their species and differed also according to the different organs of the same plants and kinetin treatment induced highly positively affect than
The Biphasic Role of Cupper and Counteraction with Azospirillum brasilense Application on Growth, Metabolities, Osmotic Pressure and Mineral of Wheat Plant  [PDF]
Hamdia M. Abd El-Samad
American Journal of Plant Sciences (AJPS) , 2017, DOI: 10.4236/ajps.2017.85078
Abstract: The interactive effect of different Cu++ concentrations (5 mM, 10 mM, 20 mM and 25 mM) and treatments with biofertilizers Azospirillum brasilense on growth, metabolites, minerals and osmotic pressure of wheat plants was investigated. Shoots and roots of wheat plant were differentially response to Cu++ treatments, while shoot organ response positively to this treatment, root response negatively. The positive effect of Cu++ in shoot organ was concomitant with the increase in the production of fresh, dry matter, length and water content and this related with the accumulation of soluble sugar, soluble protein and mineral as a result of increasing osmotic pressure. On the other side, the negative effect of Cu++ on root organ was concomitant with the decrease in production of fresh, dry matter, length and water content that related with the reduction in the accumulation of soluble sugar and mineral with the insignificant change in osmotic pressure. Azospirillum brasilense inoculation increased the accumulation of soluble sugar and soluble protein which reflected an increase in the production of fresh, dry matter and water content with increasing values of osmotic pressure of the tested plants under Cu++ treatment. Finally, wheat plants response differentially to Cu++ treatment according to its organ and Azospirillum brasilense treatment improved wheat plant efficiency to tolerate the effect of Cu++ stress.
Growth, Metabolites, Protein Profile and Esterase Enzyme of Wheat Grown under Osmotic Stress with Exogenous Application of Allium sativum  [PDF]
Hamdia M. Abd El-Samad, D. Mostafa
American Journal of Plant Sciences (AJPS) , 2018, DOI: 10.4236/ajps.2018.94069
Abstract:

The present work was conducted to lower and alleviate the saline injury by using natural products in garlic extract application on growth, metabolites, protein pattern and esterase enzyme of wheat plants. This study was conducted that wheat plant cv. Gimiza 11 response to osmotic stress effects and in general showed a variable response between different organs. The aerial parts of plants not only alleviated salinity injury but activated the fresh and dry matter productions. In root these parameters decreased as increasing salinity stress. Length of the shoots, roots and spikes run parallel with the previous results. Photosynthetic pigment enhanced markedly the increasing osmotic stress levels. The effect of garlic was reflected on the accumulation of soluble sugar and soluble protein in both roots and spikes, and a reduction of Na+ and an increase in K+ under garlic treatments were recorded. In the present study, staining intensity of protein bands of wheat plant was decreased as osmotic stress increased but the number of bands was increased up to -0.9 MPa, after that level a slight decrease was recorded (for control induction, 12 bands, -0.3 MPa, 16 bands, -0.6 MPa 14 bands, -0.9 14 bands, -1.2 MPa 11 bands and final 11 bands for -1.5 MPa). Induction protein bands for control plus garlic were 12 bands, for -0.3 MPa OSL plus garlic were 13 bands, for -0.6 MPa OSL plus garlic were 12 bands, for -0.9 MPa OSL plus garlic were 12 bands, for -1.2 MPa OSL were 8 bands and finally for -1.5 MPa OSL plus garlic were 9 bands. Electrophoresis studies of esterase showed wide variations in their intensities and densities among all treatments. There were 6 isozymes forms of esterase under OSL and with garlic but intensity was different. It seems that garlic

The Combined Action Strategy of Two Stresses, Salinity and Cu++ on Growth, Metabolites and Protein Pattern of Wheat Plant  [PDF]
Hamdia M. Abd El-Samad, D. Mostafa, Kholoud N. Abd El-Hakeem
American Journal of Plant Sciences (AJPS) , 2017, DOI: 10.4236/ajps.2017.83043
Abstract: The response of wheat plants to different osmotic stress levels varied among the different organs root, shoot and spike and the situation of these organs with application of two Cu++ levels 5 mM and 25 mM as CuSO4. The sensitivity of root organ was related with reduction in fresh, dry matter and length. This resulted from reduction of soluble sugar reflected a reduction in water uptake and K+ content of the cell sap. In the moderate organ spike, the reduction in fresh, dry matter and length were concomitant with the accumulation of soluble sugar and a huge accumulation of soluble protein. In the higher organ shoot, this related with more water uptake which in turn induced an accumulation of soluble protein and cofactor K+ content. It can be recorded that shoot was higher Na+ accumulation than root and spike. Data also showed further stimulatory effect on growth parameters by Cu++ applications with either concentration (7.5 mM and 25 mM). Irrigating the soil with either 7.5 or 25 mM CuSO4 induced a huge accumulation in soluble sugar, soluble protein and nitrate reductase. Cupper treatment with either concentration 7.5 mM or 25 mM induced a marked decrease in Na+
The Potential Role of Cu2+ and Combined Action with IAA on Tolerance Strategy of Two Broad Bean Cultivars  [PDF]
Hamdia M. Abd El-Samad, Mohamed Abdo K. Shaddad, Kholoud N. Abd El-Hakeem
American Journal of Plant Sciences (AJPS) , 2018, DOI: 10.4236/ajps.2018.910153
Abstract: The present work was conducting to study the strategy response of two broad bean cultivars Assiut 84 and Assiut 125 to different Cu2+ concentrations 100 ppm, 200 ppm, 300 ppm and 350 ppm in addition to control and interactions with IAA treatments. The dry matter exhibited the biphasic effect of Cu2+ on the growth criteria of the two broad bean cultivars. While the lower and moderate doses of Cu2+ (100 ppm and 200 ppm) stimulated the growth of the two cultivars, the higher doses revealed the opposite event where the growth dropped in both cultivars. This effect was more pronounced in cv. Assiut 84 than in cv. Assiut 125 and also at the higher Cu2+ concentration the growth dropped slightly in cv. Assiut 84 and highly significantly in cv. Assiut 125. The percent of increase in dry matter at 200 ppm in stem and leaf of cv. Assiut 84 was 120.45% and 155.31%, otherwise this percent of increase in these organs of cv. Assiut 125 was 114.29% and 131.41%. However the percent of reduction at 350 ppm Cu2+ in root and stem of cv. Assiut 84 was 74.13%, 79.23% and in root, stem and leaf of cv. Assiut 125 was 59.27%, 70.91%, 70.76% compared with control plants. Soluble carbohydrate in cv. Assiut 84 and cv. Assiut 125 was markedly increased while soluble protein was decreased in root, stem and in leaves at lower Cu2+ concentration.
Interactive Effects of Drought Stress and Phytohormones or Polyamines on Growth and Yield of Two M(Zea maize L) Genotypes  [PDF]
M. A. K. Shaddad, M. Hamdia Abd El-Samad, H. T. Mohammed
American Journal of Plant Sciences (AJPS) , 2011, DOI: 10.4236/ajps.2011.26094
Abstract: Two maize genotypes (Nefertiti and Bashaier) were picked up from nine maize genotypes during the early vegetative growth (25 days) to be cultivated in open field upon the crop yield under the different drought stress levels (90,70,50,30) or under the interaction effect of drought stress and phytohormones or polyamines. According to the data of growth criteria, the maize genotype Nefertiti was found to be the most drought sensitive genotype, while the genotype Bashaier was found to be the most drought resistant genotype. Additionally while the photosynthetic pigments remained more or less unchanged in genotype Bashaier, their biosynthesis destroyed earlier in the drought sensitive genotype (Nefertiti). Also while the genotype Bashaier absorbed and accumulated a sufficient amount of mono and divalent cations (K+, Ca++ and Mg++), the genotype Nefertiti did not. Accordingly while the genotype Bashaier gave a crop yield up to 50% field capacity, the genotype Nefertiti gave a crop yield only up to 70% field capacity and failed to give a crop yield beyond this level. The interaction effect of drought stress and phytohormones and polyamines improved the all above characteristics. Interestingly each of these activators considerably improved the production of crop yield only in genotype Bashaier specially polyamines they produced more than 60% field capacity and at the level of 30% field capacity (the level which did not give crop yield in this genotype). However, phytohormones in generally did not make an important effect on the crop yield in genotype Nefertiti although they improved the dry matter production during the vegetative stages. Such situation seemed to be complicated and borne many questions to be studied in the future.
The effect of NaCl salinity and sodium pyruvat on growth of cucumber plant
Hamdia M. Abd El-Samad
Acta Societatis Botanicorum Poloniae , 1994, DOI: 10.5586/asbp.1994.041
Abstract: Salinity affected growth, the contents of chlorophyll, carotenoids, saccharides, nitogen content and some minerals (Na, K, Ca, Mg, P) in cucumber plants (Cucumis sativus). Spraying the shoot system with sodium pyruvate greatly ameliorated the adverse effects of NaCl salinity. This counteraction was associated with an increase in the contents of saccharides, amino acids, proteins, Ca and P.
The role of amino acids in improvement in salt tolerance of crop plants
Abd El-Samad H. M.,M. A. K. Shaddad,N. Barakat
Journal of Stress Physiology & Biochemistry , 2010,
Abstract: The present work has been performed to study the growth and metabolic activities of maize and broad bean plants which are shown to have a degree of sensitivity to salinity and to determine the role of amino acids proline or phenylalanine in increasing the salt tolerance of theses plants. Dry mass, water content, leaf area and photosynthetic pigment of maize and broad bean plants decreased with increasing salinity. These changes were accompanied with a drop in the contents of soluble sugars, soluble proteins and amino acids. This was accompanied by a marked increase in the proline content. When maize and broad bean plants sprayed with proline or phenylalanine the opposite effect was occurred, saccharides as well as proteins progressively increased at all sanitization levels and proline concentration significantly declined. Salinity significantly increased the sodium content in both shoots and roots of maize and broad bean plants, while a decline in the accumulation of K+, Ca++, Mg++ and P was observed. Amino acids treatments markedlyaltered the selectivity of Na+, K+, Ca++ and P in both maize and broad bean plants. Spraying with any of either proline orphenylalanine restricted Na+ uptake and enhanced the uptake of K+, K+/Na+ ratio, Ca++ and P selectivity in maize and broad bean plants.
On the SigmaN cusp in the pp -> pK+Lambda reaction
S. Abd El-Samad,E. Borodina,K. -Th. Brinkmann,H. Clement,E. Doroshkevich,R. Dzhygadlo,K. Ehrhardt,A. Erhardt,W. Eyrich,H. Freiesleben,W. Gast,A. Gillitzer,D. Grzonka,C. Hanhart,F. Hauenstein,P. Klja,K. Kilian,M. Krapp,J. Ritman,E. Roderburg,M. Roeder,M. Schulte-Wissermann,W. Schroeder,T. Sfzick,G. J. Wagner,P. Wintz,P. Wuestner
Physics , 2012, DOI: 10.1140/epja/i2013-13041-8
Abstract: Measurements of the $pp \to pK^+\Lambda$ reaction at $T_p$ = 2.28 GeV have been carried out at COSY-TOF. In addition to the $\Lambda p$ FSI and $N^*$ resonance excitation effects a pronounced narrow structure is observed in the Dalitz plot and in its projection on the $p\Lambda$-invariant mass. The structure appears at the $pp \to $N$K^+\Sigma$ threshold and is interpreted as $\Sigma$N cusp effect. The observed width of 20 MeV/$c^2$ is substantially broader than anticipated from previous inclusive measurements. Angular distributions of this cusp structure are shown to be dissimilar to those in the residual $pK^+\Lambda$ channel, but similar to those observed in the $pK^+\Sigma^0$ channel.
Discriminating between rival biochemical network models: three approaches to optimal experiment design
Bence Mélykúti, Elias August, Antonis Papachristodoulou, Hana El-Samad
BMC Systems Biology , 2010, DOI: 10.1186/1752-0509-4-38
Abstract: In this paper we develop methodologies for the optimal design of experiments with the aim of discriminating between different mathematical models of the same biological system. The first approach determines the 'best' initial condition that maximizes the L2 (energy) distance between the outputs of the rival models. In the second approach, we maximize the L2-distance of the outputs by designing the optimal external stimulus (input) profile of unit L2-norm. Our third method uses optimized structural changes (corresponding, for example, to parameter value changes reflecting gene knock-outs) to achieve the same goal. The numerical implementation of each method is considered in an example, signal processing in starving Dictyostelium am?b?.Model-based design of experiments improves both the reliability and the efficiency of biochemical network model discrimination. This opens the way to model invalidation, which can be used to perfect our understanding of biochemical networks. Our general problem formulation together with the three proposed experiment design methods give the practitioner new tools for a systems biology approach to experiment design.Mathematical modelling has become an indispensable tool for modern systems biology [1,2]. Simple qualitative descriptions are proving increasingly insufficient for understanding the intricate dynamical complexity of biological phenomena. As a result, quantitative mathematical models are now routinely used in order to describe and analyze the complex dynamics generated by protein interactions [3], metabolic pathways [4,5], regulation of gene expression [6], and other biochemical processes.A successful modelling effort is necessarily an iteration between model analysis and experiments. Testing the appropriateness of a mathematical description of any physical process should be done against experimental data, but at the same time, models should inform the design of new experiments. Traditionally, experiments have been designed usin
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