The Experts below are selected from a list of 7689 Experts worldwide ranked by ideXlab platform
Marisa López Bilbao - One of the best experts on this subject based on the ideXlab platform.
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Sunflower (Helianthus annuus L.).
Methods in molecular biology (Clifton N.J.), 2014Co-Authors: Laura M Radonic, Dalia M Lewi, Nilda E López, A. Sousa Escandón, H. Esteban Hopp, Marisa López BilbaoAbstract:Sunflower (Helianthus annuus L.) is still considered as a Recalcitrant Species to in vitro culture and transformation in spite of the publication of different protocols. Here we describe a routine transformation system of this crop which requires mature HA89 genotype seeds and Agrobacterium tumefaciens EHA105 strain for gene delivery, being both easily available. Selection of transformed shoots depends on root development in kanamycin-selective media, instead of shoot color, avoiding selection of escapes. The establishment of this protocol proved successful for the incorporation of both reporter and agronomic important genes and also for the evaluation of the specific expression patterns of different promoters in transgenic sunflower plants. Stable expression of the incorporated transgenes was confirmed by RT-PCR and GUS reporter gene visualization. Stable inheritance of transgenes was successfully followed until T2 generation in several independent lines.
W. E. Finch-savage - One of the best experts on this subject based on the ideXlab platform.
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Seed development in the Recalcitrant Species Quercus robur L.: germinability and desiccation tolerance
Seed Science Research, 1992Co-Authors: W. E. Finch-savageAbstract:AbstractChanges in germination and desiccation sensitivity were measured throughout the seed expansion phase of development in fruits of Quercus robur L. The onset of a reduction in sensitivity to desiccation during development on the tree coincided with acquisition of the capacity for seed germination on moist sand substrate. Tolerance of desiccation then increased throughout development to shedding, but viability was still lost at a relatively high moisture content, and seeds did not therefore pass through a fully desiccation-tolerant phase. These data suggest that desiccation sensitivity in Q. robur may have resulted from the premature termination of development.No desiccation was required to initiate germination in prematurely harvested fruits orseeds. Germination rate of seeds on moist sand increased at successive harvests during development, and was also increased by presoaking seeds in water. Variation in germination rate following shedding was not related to seed size or moisture content, but was affected by shedding date. This effect was not observed when the pericarp was removed.
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Embryo Water Status and Development of the Recalcitrant Species Quercus robur L: Determination of Water Relations Parameters by Pressure-Volume Analysis
Journal of Experimental Botany, 1992Co-Authors: R. I. Grange, W. E. Finch-savageAbstract:The water status and water content of embryos of Quercus robur have been determined during development. Using psychrometers, changes in osmotic potential at full imbibition and the proportion of water at zero reciprocal water potential, R 0 , were estimated from curves of embryo relative water content and reciprocal water potential
Laura M Radonic - One of the best experts on this subject based on the ideXlab platform.
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Sunflower (Helianthus annuus L.).
Methods in molecular biology (Clifton N.J.), 2014Co-Authors: Laura M Radonic, Dalia M Lewi, Nilda E López, A. Sousa Escandón, H. Esteban Hopp, Marisa López BilbaoAbstract:Sunflower (Helianthus annuus L.) is still considered as a Recalcitrant Species to in vitro culture and transformation in spite of the publication of different protocols. Here we describe a routine transformation system of this crop which requires mature HA89 genotype seeds and Agrobacterium tumefaciens EHA105 strain for gene delivery, being both easily available. Selection of transformed shoots depends on root development in kanamycin-selective media, instead of shoot color, avoiding selection of escapes. The establishment of this protocol proved successful for the incorporation of both reporter and agronomic important genes and also for the evaluation of the specific expression patterns of different promoters in transgenic sunflower plants. Stable expression of the incorporated transgenes was confirmed by RT-PCR and GUS reporter gene visualization. Stable inheritance of transgenes was successfully followed until T2 generation in several independent lines.
William E Finchsavage - One of the best experts on this subject based on the ideXlab platform.
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free radical processes and loss of seed viability during desiccation in the Recalcitrant Species quercus robur l
New Phytologist, 1992Co-Authors: George A F Hendry, William E Finchsavage, Christopher P Thorpe, Neil M Atherton, Sarah M Buckland, Katrina Nilsson, Wendy E SeelAbstract:SUMMARY Loss of moisture in mature seeds of Quercus robur L. was associated with loss of viability, a rise in lipid peroxidation and build-up of free radicals. Radical-initiated damage was largely confined to the embryonic axes as their moisture contents declined to below 47 %. The accumulation of a stable free radical in axial tissue, detected by electron para-magnetic resonance (EPR), was indistinguishable from the EPR response previously shown in a moss on droughting and maize roots on desiccation. A minor higher-field component appeared to represent an intermediate stage in the sequence of free radical reactions associated with loss of water. Using seeds from freshly abscised fruits dried to different moisture contents, protective mechanisms against activated forms of oxygen were monitored in cotyledons and in embryonic axes. The two tissues exhibit distinctly different molecular defences against oxidative attack; that in the cotyledons being predominantly enzymatic, with relatively high and increasing activities of superoxide dismutase and glutathione reductase; that in the axes being largely through the anti-oxidants, ascorbic acid and alpha-tocopherol. We conclude that a decrease in enzymic protection against oxidative attack in the axes, associated with diminishing concentrations of alpha-tocopherol (and depletion of the precursor gamma-tocopherol) as moisture was lost, was directly linked with lipid peroxidation and free radical formation in the axes and that these events taken together may contribute to loss of viability in these Recalcitrant seeds.
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seed development in the Recalcitrant Species quercus robur l water status and endogenous abscisic acid levels
Journal of Experimental Botany, 1992Co-Authors: William E Finchsavage, H A Clay, P S Blake, G BrowningAbstract:Water status and endogenous ABA levels were measured during the development of the embryonic axis and cotyledons in fruits of Quercus robur L
G Browning - One of the best experts on this subject based on the ideXlab platform.
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seed development in the Recalcitrant Species quercus robur l water status and endogenous abscisic acid levels
Journal of Experimental Botany, 1992Co-Authors: William E Finchsavage, H A Clay, P S Blake, G BrowningAbstract:Water status and endogenous ABA levels were measured during the development of the embryonic axis and cotyledons in fruits of Quercus robur L
