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31.
Yongru Sun Berthold M. Heil Günter Kahl Hans Willy Kohlenbach 《Plant Cell, Tissue and Organ Culture》1987,8(1):91-100
Calli were initiated from flower buds, gynoecia and inflorescence segments of Haworthia magnifica v. Poelln. and subcultured on solid medium. Two liquid culture steps were necessary to prepare the calli for the isolation of protoplasts capable of sustained cell divisions. Plants were regenerated from protoplast-derived calli. The influence of both the osmolality of the culture media and exudates on the viability of protoplasts and protoplast-derived cell colonies is briefly discussed. 相似文献
32.
Ethylene treatment (approx. 20 l ·1-1 in air for 2 d) of tobacco (Nicotiana tabacum L. cv. Havana 425) plants markedly increases the endo--1,3-glucanase (EC 3.2.1.39) content of leaves. The antigenic form of the enzyme induced is the same one whose production is blocked by treating cultured cells with combinations of auxin (1.1 · 10-5 M -naphthaleneacetic acid) and cytokinin (1.4 · 10-6 M kinetin). Evidence is presented that cultured tobacco cells require ethylene for -1,3-glucanase accumulation: i) ethylene treatment increased the accumulation of \-1,3-glucanase in callus tissues >10 d after subculturing and in cell-suspension cultures; ii) callus tissues can produce ethylene; iii) conditions known to inhibit ethylene production (1 mM CoCl2; 33° C treatment) or ethylene action (approx. 1.6 mmol · 1-1 norbornadiene in air) inhibited -1,3-glucanase accumulation by callus tissues treated for 4 d following subculturing; and, these inhibitory effects were prevented by exogenous ethylene. Combinations of auxin and cytokinin blocked ethylene-induced accumulation of -1,3-glucanase by cell-suspension cultures. The results favor a model in which ethylene induces results favor a model in which ethylene induces 1,3-glucanase accumulation, and auxin and cytokinin inhibit this induction process.Abbreviations NAA
-naphthaleneacetic acid
- NDE
norbornadiene 相似文献
33.
R. J. Singh K. P. Kollipara T. Hymowitz 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1987,74(3):391-396
Summary The exploitation of wild perennial species of subgenus Glycine has been formidable in soybean breeding programs because of extremely poor crossability and an early pod abortion. The combination of gibberellic acid application to hybridized gynoecia and improved seed culture media formulations resulted in a new intersubgeneric hybrid between Glycine max (L.) Merr. (2n=40) and G. clandestina Wendt. (2n=40). Of the 31 immature seeds cultured, 1 regenerated 21 plants through organogenesis while the remaining 30 failed to germinate. All the regenerated plants were similar morphologically, carried expected 2n=40, possessed hybrid isozyme patterns and were completely sterile. Complete absence of chromosome pairing was observed in 40.9% sporocytes. The occurrence of 1 to 6 loosely paired rod bivalents suggests some possibilities of allosyndetic pairing. Hybrid plants set aborted pods after backcrossing to G. max. 相似文献
34.
The effect of sucrose on the levels of abscisic acid, indoleacetic acid and zeatin/zeatin riboside in wheat ears growing in liquid culture 总被引:1,自引:0,他引:1
The influence of a varied sucrose supply on grain size and hormonal contents of detached wheat ears ( Triticwn aestivum L. cv. Schirokko) was investigated throughout grain development. In ears led limited amounts, or no sucrose, grain weights in both proximal and distal grain positions of the ear were reduced. Radioimmunoassay for abscisic acid, indoleacetic acid and zeatin/zeatin riboside showed that the changes in the levels of these hormones in grains and bracts were comparable to intact ears when detached ears were well supplied with sucrose. Under conditions of limited sucrose supply, higher abscisic acid levels in the distal and proximal grains of detached ears were found compared to ears supplied with adequate sucrose. Limiting sucrose supply to the ear did not alter the levels of indoleacetic acid or zeatin/zeatin riboside in either the grains or bracts of detached ears. 相似文献
35.
Leaves were obtained from 4-week-old seedlings of Lavandula latifolia Medicus grown in vitro. Leaf explants were then cultured on MS medium supplemented with different concentrations and combinations of the auxins IAA or NAA with the cytokinin BA and maintained under three illumination conditions, 16h photoperiod, darkness or darkness followed by a photoperiod, to assess morphogenic responses. Irrespective of illumination conditions, bud regeneration was achieved only in media containing BA or BA/auxin combinations, with the best results being obtained in the presence of BA and 0.06 or 0.6 M IAA or NAA. A photoperiod of 16h appeared to yield the best response in terms of bud regeneration percentage. High auxin concentrations (6.0 or 11.0 M) inhibited bud differentiation, especially when explants were cultured in darkness. On the other hand, low auxin levels and photoperiod improved shoot development. Excised shoots were induced to form roots by transfer to hormone-free MS medium with macronutrients at half strength. The obtained plantlets were ultimately grown in the greenhouse.Abbreviations BA
benzyladenine
- BM
basal medium
- IAA
indoleacetic acid
- MS
Murashige & skoog
- NAA
-naphthaleneacetic acid 相似文献
36.
In vitro enzyme activities of glycolysis, pentose-phosphate pathway and dark CO2 fixation were assayed in batch cultures of heterotrophic Catharanthus roseus cells under various gassing rates and partial pressures of carbon dioxide. Detrimental effects of low pCO2 culture conditions on the growth characteristics could be linked to marked changes in levels of enzymes of primary metabolism during growth. The enzyme levels observed during the early stages of growth were found to be more stable when a constant pCO2 (20 mbar) was maintained and enabled exponential growth to be reached more rapidly.The importance of carbon dioxide as a conditioning factor of the culture medium is discussed. 相似文献
37.
WALTER C. QUEVEDO JACOB DYCKMAN RUTH HALABAN GISELA E. MOELLMANN JANET M. COWAN THOMAS J. HOLSTEIN 《Pigment cell & melanoma research》1988,1(Z1):124-131
The BULT melanoma originated at Brown University as a spontaneous, small black nodule on the tail of an adult female mouse of the LT/Ch strain. Histological examination of a portion of the tumor indicated that it was intradermal and consisted predominantly of heavily melanized, ovoid to fusiform cells with melanin-laden macrophages scattered among them. The BULT melanoma has been maintained in LT/Ch mice for approximately 5 years by periodic transplantation, at first subcutaneously on the flanks and, more recently, intramuscularly in the hind legs. The shift in transplantation site was made following a marked decline in the growth of subcutaneous grafts. The transplants have retained the uniform deep-black melanization and general histology of the primary melanoma. Numerous melanosomes at all stages of development are found within the melanoma cells. DOPA-positive cytoplasmic vesicles are abundant. Occasional autophagic vacuoles containing clusters of melanosomes are also present. A few metastases from the transplanted melanoma have been observed in lymph nodes and on one occasion in the lungs. When grown in vitro, BULT melanoma cells do not require special growth promoting agents (e.g., TPA; cAMP) in order to proliferate. The BULT melanoma differs in one or more respects from each of the other three transplantable spontaneous mouse melanomas widely used in cancer research. In addition, it arose in a strain of mice characterized by the spontaneous death of melanocytes while the latter are engaged in synthesizing eumelanin within hair follicles. Karyotypic analysis of cultured cells showed a modal chromosome number of 68 with a range of 58–72 chromosomes. 相似文献
38.
A computerized mechanical cell stimulator for tissue culture: Effects on skeletal muscle organogenesis 总被引:8,自引:0,他引:8
Herman H. Vandenburgh 《In vitro cellular & developmental biology. Plant》1988,24(7):609-619
Summary A tissue culture system has been developed which can mechanically stimulate cells growing on a highly elastic plastic substratum
in a 24-well cell growth chamber. The collagen-coated substratum to which the cells attach and grow in the Mechanical Cell
Stimulator (Model I) can be repetitively stretched and relaxed by stepper motor with linear accuracy of 30 μm. The activity
controlling unit is an Apple IIe computer interfaced with the cell growth chamber via optical data links and is capable of
simulating many of the mechanical activity patterns that cells are subjected to in vivo. Primary avian skeletal myoblasts
proliferate and fuse into multinucleated myotubes in this set-up in a manner similar to normal tissue culture dishes. Under
static culture conditions, the muscle cells differentiate into networks of myotubes which show little orientation. Growing
the proliferating muscle cells on a unidirectional stretching substratum causes the developing myotubes to orient parallel
to the direction of movement. In contrast, growing the cells on a substratum undergoing continuous stretch-relaxation cycling
orients the developing myotubes perpendicular to the direction of movement. Neither type of mechanical activity significantly
affects the rate of cell proliferation of the rate of myoblast fusion into myotubes. These results indicate that during in
vivo skeletal muscle organogenesis, when substantial mechanical stresses are placed on skeletal muscle cells by both continuous
bone elongation and by spontaneous contractions, only bone elongation plays a significant role in proper fiber orientation
for subsequent functional work.
Supported by grants NS16753, AR36266, and RR05818 from the National Institutes of Health, Bethesda, MD. 相似文献
39.
Summary We have devised techniques to culture whole, dissected embryos of Drosophila melanogaster. We examine multiple aspects of the morphological and physiological development of the epidermis, musculature, nervous system, and internal organs in this cultured preparation, and show that in vitro development closely parallels normal embryogenesis. These techniques permit a wide range of experimental manipulations during embryogenesis and allow us to extend observations through late embryonic stages, after cuticle deposition. Applications of this technique are presented. 相似文献
40.
Jeffrey D. Macklis Richard L. Sidman H. David Shine 《In vitro cellular & developmental biology. Plant》1985,21(3):189-194
Summary A new type of collagen surface for use with cultures of peripheral nervous system cells is described. Collagen is derivatized
to plastic culture dishes by a cross-linking reagent, 1-cyclohexyl-3-(2-morpholinoethyl)-carbodiimide-metho-p-toluenesulfonate (carbodiimide), to form a uniform and durable surface for cell attachment and growth that allows dry storage,
long-term culture, and improved microscopy. Surfaces of collagen derivatized to plastic were compared to surfaces of adsorbed
or ammonia-polymerized collagen in terms of collagen binding and detachment, growth by dorsal root ganglion cells, and electron
microscopy appearances. Derivatized collagen surfaces retained more collagen and showed much less evidence of degradation
and cellular damage over periods of many weeks than did conventional adsorbed surfaces. Long-term survival of cells on derivatized
collagen was far superior to that on the other surfaces, with almost 90% of cultures still viable after 10 wk. Transmission
electron microscopy showed an organized layer of single fibrils that supported cell growth well, and scanning electron microscopy
demonstrated an increased uniformity of derivatized collagen surfaces compared to ammoniated collagen surfaces. Applications
for this improved substrate surface are discussed.
This work was supported by the Leopold Schepp Foundation, the Dysautonomia Foundation, National Institutes of Health Grants
NS14768 and NS11237, and Institutional Core Grant HD06276. 相似文献