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1.
The effect of oxygen supply on the growth of suspension cultures of Catharanthus roseus in Erlenmeyer flasks was investigated. Below a critical oxygen supply rate the culture could not survive. By increasing the oxygen supply, a point is reached where the culture survives but no growth is possible. At higher oxygen supply rates there is a regime where both growth rate and the maximum biomass concentration increase with oxygen supply. Eventually there comes a point where no further increase in biomass is achieved, probably due to the depletion of the sugars; however, the growth rate continues to increase with oxygen supply until a maximum growth rate is obtained. The ratio of fresh to dry weight at maximum fresh weight increased with shaker table speed of rotation accompanied by a greater rate of sugar depletion. 相似文献
2.
Conditions necessary for the isolation and culture of protoplasts from suspension cultures of sugar, fodder and garden beets were investigated. Good yields of protoplasts were obtained by treating cells with a mixture of cellulase, Macerozyme and Driselase enzymes. Nutritional requirements of beet protoplasts were found to be quite simple: protoplasts could be cultured in MS, B5 or PGo based media with 0.4 M glucose with the optimum result being produced on KM8p medium. Plating efficiency (P.E) was genotype-dependent with the sugar beet giving better P.E. than the fodder or garden beets used, and higher values being achieved with the use of desalted Driselase for isolation followed by culture on KMBp medium.Abbreviations 2,4-D
2,4-dichlorophenoxyacetic acid
- BAP
N6 benzylaminopurine
- NAA
naphthaleneacetic acid
- P.E.
plating efficiency
- *
University of Birmingham beet germplasm accession number 相似文献
3.
Protoplasts isolated from suspension cultures of atrazine resistant black nightshade (Solanum nigrum L.) a weed biotype, were enucleated by centrifugation through a stepwise mannitol/sucrose gradient. Two cytoplast, enucleated subprotoplast, bands were routinely formed: one, a minor band at the 6.4%/18.2% mannitol border containing highly vacuolate cytoplasts with 95%+ enucleation; secondly a major cytoplast band at the 18.2% mannitol/33% sucrose border containing 90%+ enucleated protoplasts in quantities up to 4 million per 50 ml gradient tube. Efficient production of cytoplasts depended on the subculture procedures used for the cell suspensions. Optimal cytoplast yield (44%) occurred for protoplasts isolated three days after subculture. The vigor of the donor suspension cultures as visually monitored had to be controlled in order to obtain consistently high enucleation percentages.Abbreviations CPW
Cell and Protoplast Wash Solution
- 2,4-D
2,4-dichlorophenoxyacetic acid
- DMSO
Dimethylsulfoxide
- FDA
Fluorescein diacetate
- MS
Murashige and Skoog medium (1962)
- UM
Uchimiya and Murashige medium (1976) 相似文献
4.
An Ustilago maydis ergosterol biosynthesis mutant (A14) which is partially blocked in sterol 14alpha-demethylase (P45014DM) activity is described. This mutant accumulated the abnormal 14alpha-methyl sterols, eburicol, 14alpha-methylfecosterol, and obtusifoliol, along with significant amounts of ergosterol. Although the A14 mutant grew nearly as well as the wild type, it was impaired in cell extension growth, which indicated a dysfunction in apical cell wall synthesis. The mutant was also found to be hypersensitive to the azole fungicides penconazole and tebuconazole. 相似文献
5.
An in vitro binding assay involving egg plasma membrane vesicles (PMVs) of Fucus serratus L. and proteins contained in a KCl extract of sperm has been used to identify a sperm protein involved in egg binding. High-performance gel filtration (HPGF) separated the sperm KCl extract into several major fractions, and a protein (apparent M, 60 kDa) was identified as being involved in binding to the egg PMVs. This protein ran on denaturing sodium dodecyl sulfate (SDS)gels with an apparent molecular weight of 27 kDa. This suggests that either the native form of the protein is a dimer or the molecular weight on HPGF is an artifact caused by high ionic strength buffer promoting hydrophobic interactions. When KCl-sol-uble proteins were separated by SDS-polyacrylamide gel electrophoresis (PAGE), blotted onto nitrocellulose, and incubated with biotinylated egg PMVs, these bound to a band at 27 kDa, confirming the role of this protein. Addition of the Fucus sperm extract or HPGF fractions containing the binding protein to eggs in the absence of sperm induced the release of polysaccharides onto the egg cell surface. This labeling was patchy, in contrast to the uniform release of polysaccharides observed when sperm were added to eggs. The monoclonal antibody (MAb) FS17 was raised against the 27-kDa sperm protein. It labeled the sperm body and both flagella by immunofluorescence, though the sperm had to he permeabilized to observe labeling, suggesting that the epitope recognized is not exposed at the cell surface. Addition of FS17 to the KCl extract in the binding assay reduced subsequent binding of egg PMVs. Removal of the 27-kDa protein recognized by FS17 from the sperm extract prevented the binding of egg PMVs in the binding assay and the triggering of the patchy release of polysaccharides when added to eggs. Overall the results suggest that the 27-kDa sperm protein is involved in binding to the egg plasma membrane and can trigger partial activation of the egg . 相似文献
6.
Variation in chiasma frequency has been studied in PMCs of diploids and C0 autotetraploids of seven Lathyrus species exhibiting a range of genome size (10.8-19.9 pg DNA/2C). Variation in chiasma frequency showed no relation to changes in genome size, either between species or between disomic sets within nuclei. Mean chiasma frequency of the tetraploids showed a 75% increase over that in the diploids. Half of this increase represents an additive effect of chromosome doubling. Total variance in chiasma frequency of autotetraploids increases by 80% over that in diploids, in line with the square of the multiplicative effect of chromosome doubling. At the diploid level, interspecific differences account for the major component of variance (63.1%). Phenotypic variation in chiasma frequency was apparent in all seven species but represented the smallest component of variance (2.8%). Chromosome doubling results in an eightfold increase in the absolute size of the phenotypic component of variance in chiasma frequency and a threefold increase in that of the cellular component. It has no effect on the absolute size of the interspecific component. 相似文献
7.
8.
Protoplasts have been obtained from vegetative thallus of the green seaweed Enteromorpha following enzymic digestion with driselase and pectinase. The viability of purified protoplast fractions was assessed by staining and measurements of O2 uptake and evolution.Abbreviations MES
2-(N-morpholino) ethanesulphonic acid
- TES
N-tris(hydoxymethyl) methyl-2 aminoethanesulphonic acid 相似文献
9.
Summary A translocation of material from chromosome 11 to chromosome 14 was identified in a 7-month-old male with microcephaly and developmental delay. The break-points appear to be on the long arm of chromosome 11, close to the centromere, and on the short arm of the 14. 相似文献
10.
The importance of the absolute and relative concentrations of monovalent and divalent cations and centrifugal speed (pressure) in the dissociation of mung bean 80S ribosomes has been examined. In the absence of Mg2+ ions, ribosome monomers yield 47S and 34S particles. Fixation with glutaraldehyde, however, indicates that this dissociation pattern is largely dependent upon high pressures developed during centrifugation and that in the absence of such artifacts the immediate product of Mg-free conditions is a 74S particle. Since 74S particles rapidly revert to the 80S form when Mg is replaced, this would appear to be a conformational change. Ribosomes were also dissociated in the presence of Mg2+ ions if the K+ ion concentration was raised. Three major particles were produced, 38S and 49S from the small ribosomal sub-unit and 60S from the large sub-unit. A proportion of the 80S monomer population is more resistant to dissociation. Experiments with puromycin indicate that the more resistant fraction probably represents ribosomes completed with nascent polypeptide resulting from polysome breakdown. 相似文献