Search results for "call"
showing 10 items of 2320 documents
Adventitious shoot regeneration from hypocotyl cultures of service tree(Sorbus domesticaL.)
1992
Effects of growth regulators and N03:NH4 ratio were investigated to determine the mor- phogenic capacity of hypocotyl explants of service tree (Sorbus domestica L.) Organogenic responses were preceded by an initial callus phase and depended mainly on the auxin type used. NAA induced root differentiation whereas IAA added to media containing BA promoted adventitious shoot regeneration. Best results were obtained with 2.5 μM each of BA and IAA (19% of caulogenic explants). This reponse was increased (up to 44%) by varying nitrate to ammonium ratio from 2:1 to 4:1.
HACANCOi : a new Hα-detected experiment for backbone resonance assignment of intrinsically disordered proteins
2020
AbstractUnidirectional coherence transfer is highly efficient in intrinsically disordered proteins (IDPs). Their elevated ps-ns timescale dynamics ensures long transverse (T2) relaxation times allowing sophisticated coherence transfer pathway selection in comparison to folded proteins. 1Hα-detection ensures non-susceptibility to chemical exchange with the solvent and enables chemical shift assignment of consecutive proline residues, typically abundant in IDPs. However, many IDPs undergo a disorder-to-order transition upon interaction with their target protein, which leads to the loss of the favorable relaxation properties. Long coherence transfer routes now result in prohibitively large dec…
Somatic embryogenesis and plant regeneration in a woody species: the European Spindle Tree (Euonymus europaeus L.).
1993
Somatic embryogenesis and subsequent plant regeneration of Euonymus europaeus L (European Spindle Tree) were obtained from square pieces of mature zygotic embryos with an intervening callus phase. Callus and somatic embryos were induced using a Murashige and Skoog's semi-solid basal medium supplemented with several combinations of auxins and cytokinins. The greatest number of somatic embryos was obtained with a continuous exposure to 22.8 μM indoleacetic acid and 0.046 μM kinetin. The frequency of somatic embryogenesis from zygotic embryos depends on the cold conservation time of seeds. The embryos frequently germinated on the same medium. Further development of somatic embryos into plantle…
Untersuchungen zur Biosynthese eines Cytokinins in Calluszellen von Laubmoossporophyten
1973
When callus cells derived from the sporogon of the hybrid Funaria hygrometrica x Physcomitrium piriforme are supplied with adenine-8-14C, they produce a labelled cytokinin which has the same chromatographic behavior as N6-γγ-(dimethylallyl)aminopurine. The cytokinin is the first radioactive product that can be detected in the culture medium. It is formed as long as labelled adenine is available. When callus cells are grown in an optimum culture medium containing amino acids, about 10% of the radioactivity supplied as adenine is found in the cytokinin. When the cells are grown in a medium without amino acids, the RNA-content of the cells and the total yield of cytokinin decrease, but about 1…
The apparent loss of tissue culture competence during leaf differentiation in yams (Dioscorea bulbifera L.)
1993
Explants taken from the leaves of yams (Dioscorea bulbifera L.) at different stages of development were cultured in vitro on a checkerboard using various combinations and/or concentrations of auxin (2,4-d) and cytokinin (6-BAP). An addition of cytokinin to the culture media was not essential for callus induction from explants derived from young leaves in the very early stages of expansion. When the leaves expanded further they required cytokinin and the requirement increased considerably during expansion. Explants taken from fully expanded leaves were no longer able to proliferate, even when extremely high concentrations of cytokinins were applied. Callus grown from highly immature leaves w…
Morphogenic potential of mechanically isolated single cells from Digitalis obscura L. callus
1989
Calli from hypocotyl and root explants of Digitalis obscura L. showed regeneration of adventitious shoots, roots and embryos when transferred to Murashige & Skoog medium supplemented with cytokinins alone or in combination with auxins. Optimum shoot-bud formation was achieved in the presence of IAA and BA, while roots mainly appeared either in absence of growth regulators or with IAA and Kn. Embryo formation took place only in those combinations that included Kn. Embryo development was influenced by the type of auxin, and precocious germination occurred in media with NAA. Mechanically isolated cells from hypocotyl- and root-derived calli were plated in MS medium supplemented with several IA…
ChemInform Abstract: Tandem Asymmetric Michael Reaction-Intramolecular Michael Addition. An Easy Entry to Chiral Fluorinated 1,4-Dihydropyridines.
2010
The sequential treatment of optically active sulfoxide (I) with fluorinated nitriles and alkyl propiolates affords (sulfinylmethyl)dihydropyridines of type (IV) as single diastereomers in most cases.
Morphogenesis in callus and single-cell cultures ofLavandula latifoliaMedicus
1990
Procedures and factors promoting plant regeneration from callus and isolated cells were investigated in Lavandula latifolia Medicus. Callus was obtained from cotyledon explants cultured on MS medium supplemented with 0.34 (xM 2,4-D. These calli regenerated adventitious buds when transferred to MS medium containing either BA or several auxin (IAA or NAA)/BA combinations, best results being obtained in the presence of 8.80 (mi BA alone or in combination with 0.06 and 0.60 (xM IAA or NAA. Single cells from cotyledon-derived calli were able to proliferate as callus when plated in MS medium supplemented with IAA or several IAA/BA combinations. Best plating efficiency was achieved when cells were…
In vitro morphogenesis of grapevine (Vitis vinifera L.) inflorescence primordia, cvs Pinot Noir and Chardonnay
1998
Hormonal regulatory processes controlling in vitro morphogenesis of grapevine inflorescence primordia, excised from latent buds from November to April, were investigated. Cytokinin (benzylaminopurine, BAP), gibberellin (GA3) and auxin (3-indolebutyric acid, IBA) were used at 1 mg/L. BAP induced branch development and flower calyx differentiation. GA3 first promoted the elongation of inflorescence rachis and then promoted flower differentiation up to the formation of normal calyx and calyptra (the fused petals), while anthers and pistils were also present but not functional. IBA did not seem to be directly involved in these morphogenetic processes. After culturing for 6–7 weeks, explants bec…
Control of end-of-life oxygen-containing groups accumulation in biopolyesters through introduction of crosslinked polysaccharide particles
2021
The formulation of bio-based materials with good performance in service and controlled end-of-life is imperative for an effective circular economy. In this work, an innovative approach to induce and control the end-of-life of biodegradable polyesters through introduction of crosslinked polysaccharide particles is proposed. Chitosan (Ch) has been subjected to ionotropically crosslinking and then added to polylactic acid (PLA) at different amounts (1.0–4.0%w) by melt mixing. All obtained results suggest that the addition of crosslinked Ch (cCh) particles does not modify significantly the investigated biopolyester properties. Specifically, the thermal analysis of the composites reveals that th…