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1.
Frank J. Turano Kenneth Glade Wilson 《In vitro cellular & developmental biology. Plant》1985,21(3):135-139
Summary The feasibility of using plant cell culture to measure toxicity was determined by investigating the toxicological effects
of three chemical compounds, allyl alcohol, propargylglycine, and cadmium chloride, on cell cultures ofCatharanthus roseus G. Don (Madagascar periwinkle). Suspension cultures ofC. roseus were maintained in modified B5 medium and transferred every 5 d. Five-day-old cell cultures were exposed to various concentrations
(10,3,1,0.3,0.1,0.03,0.01,0.003,0.001,0.0003,0.0001, 0.00003, and 0.0 mM) of the toxicants in both acute and chronic toxicity tests.
In the acute test, cells were exposed to the toxicant for 24 h, washed three times with sterile medium, and plated in petri
plates with an equal volume of 1.4% agar medium. Cells in the chronic test were plated with an equal volume of 1.4% agar medium
containing various concentrations of the toxicant. Cells were incubated 28 d at 30°C in the dark. The colonies were counted
and the results plotted as percent survival versus toxicant concentration. The results indicate, at the concentrations tested,
thatC. roseus assay may be feasible in that it fulfills the criteria for a practical assay (e.g., rapid, simple, quantifiable, and reproducible).
This work was submitted to the faculty of Miami University in partial fulfillment of the requirements for the degree of Master
of Environmental Science, Institute of Environmental Sciences. 相似文献
2.
Solange Faria Lua Figueiredo Norma Albarello Vera Regina Campos Viana 《In vitro cellular & developmental biology. Plant》2001,37(4):471-475
Summary A protocol for in vitro propagation of Rollinia mucosa, an important medicinal plant, was developed. The presence of 500 mg l−1 polyvinylpyrrolidone (PVP) during explant excision was important to avoid browning. Axillary buds, adventitious buds, and
shoot cluster proliferation were achieved from epicotyl and hypocotyl explants from nursery-grown seedlings. The highest direct
organogenesis percentage from hypocotyl explants was obtained upon culture of explants on Murashige and Skoog medium supplemented
with 2.2 μM benzyladenine (BA) plus 2.32 μM kinetin. Epicotyl explants display highest regeneration frequency on a medium containing 8.8 μM BA and 0.54 μM naphthaleneacetic acid. Gibberellic acid was necessary for shoot elongation. Root induction was observed when shoots were
pretreated with activated charcoal for 7 d in the dark before culture on Woody Plant Medium supplemented with 49.21 μM indolebutyric acid for 10 d. Root development was observed when 20 g l−1 sucrose was used. Rooted plantlets were acclimatized and grown in the greenhouse. 相似文献
3.
C.J. Handley G. Speight K.M. Leyden D.A. Lowther 《Biochimica et Biophysica Acta (BBA)/General Subjects》1980,627(3):324-331
THe incorporation of [3H]glycine into acid-insoluble protein and of [3H]acetate into glysoaminoglycans by cultured chick chondrocytes was stimulated by the addition of L-glutamine to the incubation medium. The effect of exogenous L-glutamine on protein synthesis was studied further by examining changes in the sedimentation patterns on sucrose gardients of ribosomes isolated from chondrocytes incubated in presence and absence of L-glutamine. It was found that the absence of L-glutamine caused a disaggregation of poly-ribosomes that was reversed by the addition of this amino acid to the culture medium. No detectable glutamine synthetase activity could be measured in avian articular cartilage. These results indicate that L-glutamine is an essential amino acid for cartilage in that an extracellular supply of this amino acid is required for the maintenance of protein and glycosaminoglycan synthesis. A dependence on L-glutamine was also demonstrated for other avain connective tissues. 相似文献
4.
Photosynthesis,Transpiration, and Water Use Efficiency of Vegetative and Reproductive Shoots of Grassland Species from North-Eastern China 总被引:2,自引:0,他引:2
The differences in net photosynthetic rate (P
N), transpiration rate (E), and water use efficiency (WUE) between the vegetative and reproductive shoots of three native grass species from the grassland of northeastern China [grey-green and yellow green populations of Leymus chinensis (Trin.) Tzvel., Puccinellia tenuiflora (Griseb) Scrib & Merr, Puccinellia chinampoensis Ohwi] were compared. The two type shoots experienced similar habitats, but differed in leaf life-span and leaf area. The leaf P
N and WUE for the vegetative shoots were significantly higher than those for the reproductive shoots in the grasses, while their E were remarked lower in the dry season. Relative lower leaf P
N and WUE for the reproductive shoots of grassland grasses may explain the facts of lower seed production and the subordinate role of seed in the grassland renewal in north-eastern China. 相似文献
5.
Spencer C. H. Barrett 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2010,365(1537):99-109
Flowering plants display spectacular floral diversity and a bewildering array of reproductive adaptations that promote mating, particularly outbreeding. A striking feature of this diversity is that related species often differ in pollination and mating systems, and intraspecific variation in sexual traits is not unusual, especially among herbaceous plants. This variation provides opportunities for evolutionary biologists to link micro-evolutionary processes to the macro-evolutionary patterns that are evident within lineages. Here, I provide some personal reflections on recent progress in our understanding of the ecology and evolution of plant reproductive diversity. I begin with a brief historical sketch of the major developments in this field and then focus on three of the most significant evolutionary transitions in the reproductive biology of flowering plants: the pathway from outcrossing to predominant self-fertilization, the origin of separate sexes (females and males) from hermaphroditism and the shift from animal pollination to wind pollination. For each evolutionary transition, I consider what we have discovered and some of the problems that still remain unsolved. I conclude by discussing how new approaches might influence future research in plant reproductive biology. 相似文献
6.
《Molecular & cellular proteomics : MCP》2022,21(12):100438
Human pancreatic stellate cells (HPSCs) are an essential stromal component and mediators of pancreatic ductal adenocarcinoma (PDAC) progression. Small extracellular vesicles (sEVs) are membrane-enclosed nanoparticles involved in cell-to-cell communications and are released from stromal cells within PDAC. A detailed comparison of sEVs from normal pancreatic stellate cells (HPaStec) and from PDAC-associated stellate cells (HPSCs) remains a gap in our current knowledge regarding stellate cells and PDAC. We hypothesized there would be differences in sEVs secretion and protein expression that might contribute to PDAC biology. To test this hypothesis, we isolated sEVs using ultracentrifugation followed by characterization by electron microscopy and Nanoparticle Tracking Analysis. We report here our initial observations. First, HPSC cells derived from PDAC tumors secrete a higher volume of sEVs when compared to normal pancreatic stellate cells (HPaStec). Although our data revealed that both normal and tumor-derived sEVs demonstrated no significant biological effect on cancer cells, we observed efficient uptake of sEVs by both normal and cancer epithelial cells. Additionally, intact membrane-associated proteins on sEVs were essential for efficient uptake. We then compared sEV proteins isolated from HPSCs and HPaStecs cells using liquid chromatography–tandem mass spectrometry. Most of the 1481 protein groups identified were shared with the exosome database, ExoCarta. Eighty-seven protein groups were differentially expressed (selected by 2-fold difference and adjusted p value ≤0.05) between HPSC and HPaStec sEVs. Of note, HPSC sEVs contained dramatically more CSE1L (chromosome segregation 1–like protein), a described marker of poor prognosis in patients with pancreatic cancer. Based on our results, we have demonstrated unique populations of sEVs originating from stromal cells with PDAC and suggest that these are significant to cancer biology. Further studies should be undertaken to gain a deeper understanding that could drive novel therapy. 相似文献
7.
《Animal : an international journal of animal bioscience》2019,13(4):879-887
The cull ewes represent an important part of sheep flock. However, this category of animal is often submitted to under nutrition leading to poor BW and skeletal carcasses. Their rehabilitation using a high energy diet can be an alternative to improve their body condition. The objective of this experiment was to study the BW gain and carcass characteristics of Barbarine cull ewes using rosemary (Rosmarinus officinalis L.) distillation residues (RR) and extruded linseed. For this, 28 ewes above 6 years old and 33±0.5 kg of BW were divided into four groups: CCC was fed 500 g of barley-straw with concentrate, RCC received 300 g of straw and 200 g of RR as basal diet with concentrate; whereas two other groups received the experimental concentrate, containing 10% of linseed, with 500 g of straw for CLC and 300 g of straw plus 200 g of RR for RLC group. At the end of experiment (90 days), all animals were slaughtered. For all ewes, the daily concentrate intake averaged 700 g; the average daily gain was 131 g and the slaughter BW 43.4 kg without significant difference between groups. Neither basal diet nor concentrate type did affect the carcass’ weight, yield and composition. In addition, the organ’s proportions were similar for all groups. The RR intake slightly improved muscle’s protein content (P=0.03) and tended to decrease initial pH (P=0.06) and to increase meat redness (P=0.06), whereas linseed concentrate had no effect on meat color and its chemical composition. The subcutaneous fat color and firmness score relived a good quality trade for carcasses from all diets, in spite of higher yellowness and lower firmness recorded for linseed diet (P<0.05), which were moderately improved by rosemary combination with linseed. To conclude, the Barbarine cull ewes could gain up to 120 g/day in BW. The used diets permitted this BW gain without undesirable effects on carcass characteristics and meat quality. However, the study of meat fatty acid profile and antioxidant status should continue. 相似文献
8.
Abstract. 1. Eurytoma gigantea Walsh is a specialist parasitoid of the tephritid gallmaker Eurosta solidaginis (Fitch).
2. In the natural environment the incidence of parasitism by Eurytoma is greater in small galls than in large ones.
3. Laboratory experiments demonstrated that small galls are not more frequently discovered; however, oviposition attempts on small galls were more likely to be successful.
4. Eurytoma spends much time probing galls too big to penetrate; this leads to a decrease in foraging efficiency when many large galls are present.
5. The chance of successfully penetrating a gall depends on the thickness of the gall wall and the length of the parasitoid's ovipositor.
6. A simulation model was constructed which shows that a gallmak-er's chance of being parasitized depends on gall size, the number of parasitoids that discover the gall, and their ovipositor lengths. 相似文献
2. In the natural environment the incidence of parasitism by Eurytoma is greater in small galls than in large ones.
3. Laboratory experiments demonstrated that small galls are not more frequently discovered; however, oviposition attempts on small galls were more likely to be successful.
4. Eurytoma spends much time probing galls too big to penetrate; this leads to a decrease in foraging efficiency when many large galls are present.
5. The chance of successfully penetrating a gall depends on the thickness of the gall wall and the length of the parasitoid's ovipositor.
6. A simulation model was constructed which shows that a gallmak-er's chance of being parasitized depends on gall size, the number of parasitoids that discover the gall, and their ovipositor lengths. 相似文献
9.
Ciliated tracheal epithelia cell cultures were investigated immunocytochemically with anti-tubulin and colloidal gold. When rabbit tracheal cultures were fixed in paraformaldehyde, treated with acetone, anti-tubulin and a second antibody coupled to FITC, fluorescence was associated with cytoskeletal and axonemal microtubules. Cilia covering the apical surface of the ciliated tracheal cells fluoresced very brightly thus facilitating identification of this cell type. Electron microscopy of tracheal cultures fixed as above, treated with Triton-X 100 and incubated in anti-tubulin and protein A coupled to colloidal gold resulted in the highly specific localization of tubulin in ciliary axonemes and basal bodies. Omission of primary or secondary antibody resulted in extremely low levels of fluorescence while no colloidal gold particles could be detected in cultures at the electron microscopy level when rabbit anti-tubulin was omitted. 相似文献
10.
Ice crystal formation temperature was determined in the region of the crown in one group of 7-day-old intact unhardened high-salt plants of winter wheat (Triticum aestivum L. cv. Weibulls Starke II) with TA (Thermal Analysis) and DTA (Differential Thermal Analysis) methods. After exposure of another group of plants, grown for the first 7 days in the same way as the first group, to various sub-zero temperatures (-1 to 5°C), influx in roots of Rb+(86Rb+) and Ca2+(45Ca2+) and contents of K+ and Ca2+ were determined at intervals during 7 days of recovery. Ice crystal formation in the crown tissue was probably extracellular and took place at about -4°C. There was a large loss of K+ from the roots after treatment at sub-zero temperatures. This loss increased as the temperature of the sub-zero treatment decreased. During recovery, roots of plants exposed to -1, -2 and -3°C gradually reabsorbed K+. Reabsorption of K+ in roots of plants exposed to -4°C was greatly impaired. Rb+ influx decreased and Ca2+ influx increased after sub-zero temperature treatments of the plants. Active Rb+ influx mechanisms and active extrusion of Ca2+ were impaired or irreversibly damaged by the exposure. While Rb+ influx mechanisms were apparently repaired during recovery in plants exposed to temperatures down to -3°C, Ca2+ extrusion mechanisms were not. The temperature for ice crystal formation in the region of the crown tissue coincides with the temperature at which the plants lost the ability to reabsorb K+ and to repair Rb+ influx mechanisms during the recovery period. Plants were lethally damaged at temperatures below ?4°C. 相似文献