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11.
Genetic transformation of alfalfa somatic embryos and their clonal propagation through repetitive somatic embryogenesis 总被引:3,自引:0,他引:3
Slavica Ninković Jovanka Miljuš-Djukić Mirjana Nešković 《Plant Cell, Tissue and Organ Culture》1995,42(3):255-260
Genetically transformed alfalfa (Medicago sativa L., cv. Zajearska 83) plantlets were obtained by inoculating somatic embryos with Agrobacterium tumefaciens strains A281/pGA472 and LBA4404/pBI121. Single somatic embryos, 5–7 mm long, were released from a repetitively embryogenic culture, wounded, and cocultivated with the bacteria. The agar-solidified culture medium contained mineral salts, vitamins, 40 g l–1 sucrose, 1 g l–1 yeast extract and 0.05 mg l–1 BA. Five clones, transformed with A281/pGA472, and 4 clones transformed with LBA4404/pBI121, were selected for proliferation by repetitive somatic embryogenesis, on media containing 100 mg l–1 of kanamycin. The transformation of kanamycin-resistant clones was confirmed by assaying the activity of neomycin phosphotransferase II and/or -glucuronidase enzymes, and by the Southern blot analysis. It is suggested that the transformation/regeneration system based on somatic embryogenesis may be suitable for establishing transgenic alfalfa lines. The relatively low frequency of embryo transformation is compensated for by abundant proliferation in secondary somatic embryogenesis.Abbreviations BA
6-benzyladenine
- GUS
-glucuronidase
- Km
kanamycin
- NPTII
neomycin phosphotransferase II
- X-gluc
5-bromo-4-chloro-3-indolyl--glucuronic acid
- BM
basal medium 相似文献
12.
13.
The influence of external sodium concentration on potassium (depolarizing agent)-stimulated calcium uptake and Ca+-dependent acetylcholine release by rat cerebral cortex synaptosomes has been studied. It was found that increased sodium concentration decreases both the Ca2+ uptake and the acetylcholine release, whereas a low external sodium concentration is stimulatory. 相似文献
14.
Biserka Kojić-Prodić Živa Ružić-Toroš Ljubo Golič Branko Brdar Jože Kobe 《Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression》1982,698(2):105-110
The crystal and molecular structure of one imidazo[1,2-a]-s-triazine nucleoside and its antiviral activity are described. The crystal structure of 2-amino-8-(β-d-ribofuranosyl)imidazo-[1,2-a]-s-triazin-4-one monohydrate (C10H13N5O5·H2O) was solved by X-ray counter data. The compound crystallizes in the monoclinic space group P21 with cell dimensions a = 7.353 (1), b = 6.465 (1), c = 13.701 (1) Å, β = 104.64 (1)°. The structure was solved by direct methods and refined by full matrix least-squares technique to a final value of the conventional R-factor of 0.049 using 1998 observed intensities. The orientation of the base relative to the sugar ring defined in terms of rotation about the C(1′)-N(8) glycosyl bond is anti (47.8°). The ribose moiety exhibits C(2′)-endo, 2E conformation. The conformation around C(4′)-C(5′) is gauche?. Molecular packing is dominated by hydrogen bonds. Base stacking occurs long the b axis. 5-Aza-7-deazaguanosine has shown a marked antiviral activity in vitro against herpes simplex virus despite the fact that N(3) is effective as the hydrogen acceptor only. 相似文献
15.
Summary An inherited (maternal origin) 13/14 translocation with the nucleolus organizer regions eliminated and one centromere was found in an oligospermic man whose wife had had two spontaneous abortions. Meiotic studies revealed all stages of spermatogenesis with a trivalent configuration in diakinesis. Possible reasons for his subfertility and his mother's normal fertility are discussed. 相似文献
16.
17.
The effect of two constant temperatures (23°C and 28°C), mixed group (5 + 5), and isolation on the midgut amylolytic activity during adult development of Tenebrio molitor has been investigated in vitro. Higher temperatures (28°C) and mixed groups stimulate the rate of midgut amylolytic activity. After attaining the maximal level, the amylolytic activity shows fluctuations. The possible role of hormones and primer pheromones in the control of the midgut amylolytic activity in T. molitor adults is discussed. 相似文献
18.
Dr. R. Krstić 《Cell and tissue research》1976,174(1):129-137
Summary Untreated, decalcified and trypsinized acervuli from human pineal bodies were studied with the scanning and transmission electron microscope as well as by electron probe microanalysis. The mulberry-like acervuli are composed of a various number of spherical lobes (135–800 m) between which clustered groups of globuli (4–14 urn in diameter) are observed. The acervular lobes are very probably formed by an aggregation of these globuli. Small round particles 125–500 Å in diameter are observed on the surface of the pineal concretions. These are not influenced by either decalcification or trypsin treatment. The acervular mineral corresponds morphologically to hydroxyapatite. The electron probe microanalysis reveals the existence of calcium and phosphorus as main components of the acervuli. Small quantities of magnesium and strontium were also detected.Dedicated to Professor Berta Scharrer on the occasion of her 70th birthdayWith the technical assistance of Mr. P.A. MilliquetThe author wishes to thank Mr. Bauer and Mr. Fryder (Nestec SA, La Tour de Peilz) for the use of the Cambridge Stereoscan electron microscope and Dr. T. Jalanti (C.M.E., Lausanne) for his help with the use of the X-ray microanalyser 相似文献
19.
The influence of coumestrol,zearalenone, and genistein administration on insulin receptors and insulin secretion in ovariectomized rats 总被引:2,自引:0,他引:2
Nogowski L Nowak KW Kaczmarek P Maćkowiak P 《Journal of receptor and signal transduction research》2002,22(1-4):449-457
The influence of phytoestrogens (genistein and coumestrol) and mycoestrogen (zearalenone) on insulin secretion, liver insulin receptors and some aspects of lipid and carbohydrate metabolism were investigated in this study. Ovariectomized rats were injected s.c. with the above mentioned compounds in the amount of 1 mg for three days. Coumestrol and zearalenone caused a significant increase in uterus weight, similar to the effects observed after estrone action, while this effect was not observed after the genistein injection. Blood insulin level was not changed after phyto- or mycoestrogen treatment. However, coumestrol and genistein significantly decreased the binding capacity of liver insulin receptors. These changes corresponded with alterations in glucose and free fatty acids profiles in blood, as well as with glycogen content in liver. The effects observed after genistein and coumestrol injections differed from those noticed in rats treated with zearalenone or estrone. On the basis of these results we conclude that metabolic effects of high doses of coumestrol and genistein in ovariectomized rats are partly mediated by changes in insulin sensitivity of the liver and that the action of plant estrogens on metabolism is, at least to the some degree, independent of their estrogen activity. 相似文献
20.
The effect of sucrose on fruiting, seed production, and seed germination of lesser centaury [Centaurium pulchellum (Sw.) Druce] was examined using explants of flowers and flower buds. Sucrose concentrations in the culture medium ranged
from 0.003 to 0.3 M. It has been shown that the number of auxiliary buds, capsules dimension, number of viable seeds per capsule
and seed dimensions increased with the increase of sucrose concentrations. The highest values were recorded at sucrose concentrations
higher than 0.03 M, except for seeds size, which were larger at sucrose concentration ranging from 0.003 to 0.1 M. The germination
of in vitro produced seeds was affected by previous culture history: a higher germination percentage was obtained in seeds that were
raised from explants originally grown on medium with sucrose concentrations higher than 0.003 M. 相似文献