72 research outputs found
Isolation of Temperature-Sensitive Mutants of Arabidopsis thaliana That Are Defective in the Redifferentiation of Shoots
Plant 21D7 Protein, a Nuclear Antigen Associated with Cell Division, Is a Component of the 26S Proteasome
Embryogenic suspensions of adult cork oak: the first step towards mass propagation.
Abstract Protocols have been established to clone adult cork oak trees by somatic embryogenesis using semisolid medium. However, for economically viable mass propagation, embryogenic cultures in liquid medium need to be developed. In this study, suspension cultures were initiated from embryo clusters obtained by secondary embryogenesis on a gelled medium lacking plant growth regulators. After 6 days of culture, these embryo clusters generated high cell density suspensions that also contained small organized structures (embryos and embryogenic clumps). As the culture duration increased, tissue necrosis and fewer embryogenic structures were observed and the establishment of suspension cultures failed. An alternative method was found adequate for initiation of embryogenic suspensions: embryo clusters from gelled medium were briefly shaken in liquid medium and detached cells and embryogenic masses of 41?800 lm were used as inoculum. Maintenance of embryogenic suspensions was achieved using a low-density inoculum (43 mg l-1) by subculturing four embryogenic clumps of 0.8?1.2 mm per 70 ml of medium. Proliferation ability was maintained for almost 1 year through ten consecutive subcultures. The initiation and maintenance protocols first developed for a single genotype were effective when tested on 11 cork oak genotypes
Regulation of Lithospermic Acid B and Shikonin Production in Lithospermum erythrorhizon Cell Suspension Cultures
Cell suspension cultures of Lithospermum erythrorhizon produced a large amount of lithospermic acid B, a caffeic acid tetramer, as well as shikonin derivatives (each ca. 10% of dry wt.) when cultured in shikonin production medium M-9. Various culture factors for increasing the production of lithospermic acid B were investigated. Lithospermic acid B production was inhibited by 2, 4-D or NH4+, whereas it was stimulated by Cu2+. These regulatory patterns were similar to those for the production of shikonin derivatives in these cell cultures, suggestive of close relations and similar metabolic regulation between the production of these compounds. Cultivation under light illumination, however, showed that these metabolisms were independently regulated. In particular, blue light showed a stimulatory effect on lithospermic acid B production, while shikonin production was strongly inhibited, indicative of an effective condition for lithospermic acid B production
Basic study of formation of acicular crystals by chemical reactions between RuO2 and NaNO3 in a waste vitrification process
Effect of Ammonium Ion and Temperature on Anthocyanin Composition in Sweet Potato Cell Suspension Culture.
Effects of Salicylic Acid on the Production of Procyanidin and Anthocyanin in Cultured Grape Cells
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