53 research outputs found

    Effects of the Blp1 locus, which controls melanin accumulation in the barley ear, on the size and weight of seeds

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    Background. In cereals, photosynthetically active parts of the ear significantly contribute to seed size and weight at the grain-filling stage. In barley, ear tissues may accumulate melanin pigments synthesized in chloroplast-derived melanoplasts. Effects of such pigments on yield parameters of seeds have not been evaluated to date.Materials and methods. Seed weight and size assessed by image analysis were compared between two near-isogenic barley lines differing in alleles of the Blp1 gene, which determines melanin accumulation in ear tissues. Data on grainrelated parameters were collected during 6 years and include data on seeds grown either in the field or under greenhouse conditions.Results and discussion. A negative effect of the Blp1 locus on the weight of 1000 seeds harvested in the field but not in the greenhouse was revealed. To determine whether this effect is related to grain size, a comparison of two-dimensional linear parameters of seeds between the lines was performed. It was shown that unlike the length and the area of seeds, the width of seeds was also negatively affected by the Blp1 locus. Although the same factors affected the weight of 1000 seeds and the width of seeds, a correlation between them was not found, implying a dependence of seed weight on other factors such as thickness and its related parameter, seed volume.Conclusion. Effects of barely ear pigmentation and of the gene controlling it on yield-related parameters of seeds were studied here for the first time. The observed negative impact of the Blp1 locus on seed weight and size may be mediated by an interfering chloroplast activity and/or accumulation of assimilates via melanogenesis. Additional studies are necessary to test this supposition and to investigate the interaction of melanin synthesis and photosynthetic activity of the tissues accumulating this pigment

    Specificity of Growth and Synthesis of Secondary Metabolites in Cultures in vitro Digitalis lanata Ehrh.

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    Abstract: Rhizogenic, callus, and suspension cultures in vitro were obtained for Digitalis lanata and their growth, cytophysiological and biochemical characteristics were investigated. The obtained cultures were characterized by good growth characteristics (growth indexes I in the range of 5–13). Suspension cell culture had a specific growth rate μ within 0.2–0.3 days–1 and it was characterized by a two-phase growth curve (growth retardation during the exponential phase). In the obtained cultures, a study of the qualitative and quantitative composition of secondary metabolites by UPLC-ESI-MS and HPLC-ESI-MS showed the absence of cardiac glycosides. At the same time, phenylethanoids and steroidal glycosides of the furostanol type were found in all studied cultures. The total content of phenylethanoids in callus and suspension cultures was approximately 0.5% of the dry biomass. Based on the results of mass spectrometry, ten phenylethanoid structures, including digiciliside A, digiciliside B, maxoside, purpureaside E, and their methyl derivatives and isomers, and also seven furostanol glycosides with aglycones tigogenin and gitogenin were identified. It has been shown that the composition of secondary metabolites depends on the degree of cell differentiation: furostanol glycosides were prevalent in a rhizogenic culture consisting mainly of differentiated cells, while the diversity of phenylethanoids significantly increases in callus and suspension cell cultures consisting of dedifferentiated cells. The results of the study confirm the hypothesis put forward in our previous works about the specificity of secondary metabolism and its high intensity in plant cell cultures. © 2022, The Author(s).Government Council on Grants, Russian Federation: 075-15-2019-1882The work was carried out on the basis of the “Scientific and Production Biotechnological Complex for the Study, Preservation, and Practical Application of Cultured Cells and Organs of Higher Plants and Microalgae” with the financial support of the Megagrant of the Government of the Russian Federation (Agreement no. 075-15-2019-1882)

    Quantitative estimates of unique continuation for parabolic equations, determination of unknown time-varying boundaries and optimal stability estimates

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    In this paper we will review the main results concerning the issue of stability for the determination unknown boundary portion of a thermic conducting body from Cauchy data for parabolic equations. We give detailed and selfcontained proofs. We prove that such problems are severely ill-posed in the sense that under a priori regularity assumptions on the unknown boundaries, up to any finite order of differentiability, the continuous dependence of unknown boundary from the measured data is, at best, of logarithmic type

    (Table 1) Redox potential and chemical element contents in CaCO3 and amorphous silica free matter in surface layer bottom sediments of the Pacific Ocean from Hawaiian Islands to Mexico coast

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    Distribution of Fe, Mn, P, Ti, Cu, Ni, Co, V, Cr, W, Mo, and As in the surface sediment layer on the section from the Hawaiian Islands to the coast of Mexico (Mexico section) is studied. Contents of all studied elements increase from biogenic-terrigenous sediments off the coast of Mexico to pelagic red clays of the Northeast Basin, and more sharply for mobile elements - Mn, Mo, Cu, Ni, Co, and As. In near Hawaii sediments rich in coarsely fragmented volcanic-terrigenous and pyroclastic material of basaltic composition with high contents of Ti, Fe, V, Cr, W, and P, contents of these elements increase sharply, and contents of Mn, Mo, Ni, Co, and Cu for the same reason decrease sharply in comparison with red clay. Abnormally high contents of Mn, Mo, Cu, Ni, Co, and As in the upper layer of hemipelagic and transition sediments of the Mexico section result from diagenetic redistribution and their accumulation on the surface. Processes of diagenetic redistribution in hemipelagic and transition sediment mass of the Mexico section are more rapid than in similar sediments of the Japan section due lower sedimentation rates and higher initial concentrations of Mn. Basic similarity of element distribution regularities in sediments of Japan and Mexico sections is shown

    Chemical composition of bottom sediments along the Transpacific section

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    Distribution of Fe, Mn, Ti, Cu, Ni, Co, V, Cr, Mo, As in bottom sediments of a section from the Hawaiian Islands to the coast of Mexico. In the surface layer and isochronic layers of sediments from biogenic-terrigenous sediments of the Mexico coast to pelagic red clays of the Northeast Basin contents of all studied elements increase, and more sharply for mobile ones - Mn, Mo, Cu, Ni, Co, As. In near Hawaii sediments rich in coarsely fragmented volcanic-terrigenous and pyroclastic material of basalt composition enriched in Ti, Fe, Cr, V, P contents of these elements in surface sediments and in sediment mass increase and contents of Mn, Mo, Ni, Co, Cu, As (for the same reason) decrease compared to red clays. An area of hemipelagic and transition sediments is identified; these sediments have much higher contents of Mn, Fe, Cu, Ni, Mo, As, (Ba) than red clays and similar sediments of the Northwest Pacific Ocean. This is due to hydrothermal activity in the tectonically active zone at the northern extension of the East Pacific Rise. Similar character of distribution of the elements in the surface layer and in the isochrone layers of bottom sediments along the most part of the section is shown. Similarity between distribution of the elements in sediments of the western and the eastern parts of the Transpacific section is established
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