1,721,002 research outputs found
Enzimi coinvolti nell'assimilazione dello azoto in plantule di grano duro (Triticum durum Desf. cv Simeto)
No full textCoumarin inhibits the growth of carrot (Daucus carota L. cv. Saint Valery) cells in suspension culture
No full textWe used a carrot (Daucus carota L. cv. Saint Valery) cell suspension culture as a simplified model system to study the effects of the allelochemical compound coumarin (1,2 benzopyrone) on cell growth and utilisation of exogenous nitrate, ammonium and carbohydrates. Exposure to micromolar levels of coumarin caused severe inhibition of cell growth starting from the second day of culture onwards. At the same time, the presence of 50μmol/L coumarin caused accumulation of free amino acids and of ammonium in the cultured cells, and stimulated their glutamine synthetase, glutamate dehydrogenase, glucose-6-phosphate dehydrogenase and phosphoenolpyruvate carboxylase activities. Malate dehydrogenase, on the other hand, was inhibited under the same conditions. These effects were interpreted in terms of the stimulation of protein catabolism and/or interference with protein biosynthesis induced by coumarin. This could have led to a series of compensatory changes in the activities of enzymes linking nitrogen and carbon metabolism. Because coumarin seemed to abolish the exponential phase and to accelerate the onset of the stationary phase of cell growth, we hypothesise that such allelochemical compounds may act in nature as an inhibitor of the cell cycle and/or as a senescence-promoting substance
INHIBITION BY GLUFOSINATE OF GLUTAMINE SYNTETHASE OF CULTURED CELLS OF CARROT (DAUCUS CAROTA, L.): EFFECT OF GLUTAMATE.,
No full textGlutamine synthetase in cells from carrot (Daucus carota L): Interaction between phosphinothricin and glutamate
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Studio preliminare dell'effetto delle sostanze umiche sulla radicazione di espianti fogliari di Nicotiana plumbaginifolia e sull'efficienza di piastramento di cellule di Daucus carota α II
No full textMorpho-physiological traits of sugar beet exposed to salt stress
No full textSelection of traits increasing salt (NaCl) tolerance would improve the cultivation of sugar beet (Beta vulgaris L. subsp. vulgaris) in salty soils, by reducing or avoiding the usually linked losses in sugar yield and processing quality. This study analysed some adaptive morpho-physiological mechanisms in genotypes grown under controlled conditions in different salt concentrations. Parents and F1 hybrids obtained from a diallel cross were analysed for: i) mid-parent heterosis of root; ii) root length and its morphological components; and iii) length and dry weight of shoot (leaf + stem). Physiological traits such as: i) antioxidant enzyme activities in leaves; ii) root plasma membrane (pm) H+-ATPase activity; iii) leaf relative water content; and iv) shoot Na/K ratio, were also investigated. Through principal component analysis (PCA), it was possible to group the single morpho- physiological traits. This permitted discrimination of hybrids in relation to their response to salinity. The hybrid Hy-1 in presence of medium salt concentration performed well in terms of root morphology and enzyme activities, which were linked to the cell growth process. These findings evince a better understanding of the salt tolerance mechanisms in sugar beet and the identification of useful physio-biochemical traits useful for sugar beet breeding
Secondary metabolites and eco-friendly techniques for agricultural weed/pest management
Full text linkIn agro-ecosystems, pests (insects, weeds, and other plant's parasites) compete with crops for edaphic resources, negatively affecting quality and crop yields [...]
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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