共查询到20条相似文献,搜索用时 15 毫秒
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Kannan S 《Plant physiology》1969,44(10):1457-1460
The rate of Fe absorption by cells enzymically isolated from tobacco leaves is correlated with the age of the leaves from which the cells are derived. The cells obtained from younger leaves absorb Fe more rapidly than those from older ones. Ca inhibits Fe and Mn absorption. Fe and Mn are mutually antagonistic in their absorption by leaf cells. Ca enhances the inhibition of Mn absorption by Fe, but reduces the inhibition of Fe absorption by Mn. The affinity constant for Fe absorption by leaf cells is low. The chelate EDDHA (ethylenediamine di(o-hydroxyphenylacetate) competitively inhibits Fe absorption. 相似文献
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The major metabolite produced during incubation of [3H]gibberellin A1 ([3H]GA1) with barley aleurone layers is an amphoteric, water-soluble compound tentatively called [3H]ampho GA1. Formation of [3H]ampho GA1 in barley aleurones begins after a period of 2.5 hours. As judged by degradation studies as well as Sephadex column chromatography, GA1 appears to be linked to a peptide; positions C-3 and C-7 were ruled out as conjugation sites. 相似文献
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Calcium distribution was studied in oat caryopses. Using the chlorotetracycline method it was found that membrane-associated Ca2+ was present in the aleurone layer. X-ray microanalysis confirmed the presence of calcium in aleurone cells; it also demonstrated the presence of considerable amounts of calcium in the cell wall surrounding these cells.Abbreviation CTC
chlorotetracycline 相似文献
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Richard Hooley 《Planta》1982,154(1):29-40
Viable, long-lived, gibberellic acid (GA3)-responsive protoplasts have, for the first time, been isolated from aleurone layers of mature wild oat (Avena fatua L.) grain. More than 90% of the cells of aleurone layers are recovered as protoplasts, and these respond to treatment with GA3 in essentially the same manner as the tissue from which they were derived. Protoplasts become vacuolate during incubation in vitro and, although not dependent upon GA3, vacuolation is markedly stimulated by the hormone. Amylase and ribonuclease (RNase) are produced and secreted only in the presence of GA3 and only after lag periods of 3 d and 4 d respectively. The amounts of amylase produced and secreted are proportional to GA3 concentrations as low as 1.61·10-13 M. With increasing concentrations of mannitol in the culture medium both vacuolation and the GA3-induced production and secretion of enzymes are inhibited progressively, the latter being precluded by 0.6 M to 0.7 M mannitol.Abbreviations GA3
gibberellic acid3
- RNase
ribonuclease 相似文献
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Summary Typical aleurone cells occur around the periphery of the caryopsis. These cells are tabular with moderately thick walls and lack cell wall ingrowths. Transfer aleurone cells only occur adjacent to the placental vascular bundle, which supplies the developing embryo and endosperm. These specialized aleurone cells are approximately columnar, with thick walls bearing ingrowths on the outer radial and outer tangential walls. The wall ingrowths of transfer aleurone cells appear similar to those of transfer cells previously described and quite likely also function in short-distance transport of substances.Journal paper No. J-6737 of the Iowa Agricultural and Home Economics Experiment Station, Ames, Iowa. Project No. 1685. 相似文献
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Robert P. Walker Wanda M. Waterworth Michael H. Beale Richard Hooley 《Plant Growth Regulation》1994,15(3):271-279
Aleurone protoplasts of wild oat (Avena fatua L.), and subcellular fractions isolated from them, were photoaffinity labeled using the synthetic gibberellin (GA) derivative GA4-17-yl-1-(1-thia)propan-3-ol-4-azido-5-[125I]iodosalicylate. Labeled polypeptides were identified by electrophoresis under denaturing conditions followed by autoradiography. GA-photoaffinity labeling of both intact protoplasts and isolated subcellular fractions led to the covalent attachment of the reagent to many polypeptides. A 50 kD polypeptide in the soluble fraction of homogenates of aleurone protoplasts GA-photoaffinity labeled in vivo showed specific binding. The biologically active GA1, GA4 and GA4-17-yl-1(1-thia)propan-3-ol-4-azidosalicylate completed for binding whereas the biologically inactive GA8 and GA34 did not. The GA-photoaffinity labeling characteristics of this polypeptide suggested that it might interact specifically with biologically active GAs in vivo. Attempts to detect specific GA-binding in in vitro GA-photoaffinity labeling experiments met with only limited success perhaps indicating the labile nature of specific binding observed in vivo. The potential of GA-photoaffinity labeling for identifying GA-binding proteins in aleurone and other GA-responsive tissues is discussed.Abbreviations azido IAA =
5-azido-7-[3H]indole-3-acetic acid
- azido NPA =
5-azido-[3,6-3H]1-N-napthylpthalamic acid
- BTP =
1,3-bis(Tris(hydroxymethyl)methylamino)-propane
- GA4-O-ASA =
GA4-17-yl-1-(1-thia)propane-3-ol-4-azidosalicylate
- [125I]GA4-O-ASA =
GA4-17-yl-1-(1-thia)propan-3-ol-4-azido-5-[125I]iodosalicylate
- NPA =
1-Naphthylphthalmic acid
- PAGE =
Polyacrylamide gel electrophoresis
- PMSF =
phenylmethylsulfonyl fluoride
- SDS =
Sodium dodecyl sulphate
- TLCK =
L-1-Chloro-3-(4-tosylamido)-7-amino-2-heptanone-HCl 相似文献
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Aleurone tissue from undried immature developing wheat grains (Triticum aestivum L. cv. Sappo), normally insensitive to gibberellic acid, can be made to respond to the hormone by a series of temperature treatments. Incubation of the de-embryoed grains at temperatures above 27° C for at least 8 h causes the tissue to become sensitive. Prolonged incubation at temperatures below 27° C does not effect a change in sensitivity. In addition to the requirement for exposure to an elevated temperature for a period of several hours the tissue must also subsequently be subjected to a period at a lower temperature for just a few seconds for the response to be observed. Once sensitized, the tissue remains responsive to gibberellic acid for substantial periods of time. Exposure of the tissue to temperatures which induce sensitivity to gibberellic acid also results in an increased leakage of amino acids. It is suggested that the increase in sensitivity to gibberellin requires two separate processes to take place. One could be a homeoviscous adaptation of the cell membranes in response to elevated temperature, the other a subsequent, permanent change in conformation of membrane components. 相似文献
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A method for isolating viable protoplasts in high yield from the aleurone layers of developing wheat grains is described, and the techniques for their subsequent culture outlined. Protoplasts from untreated tissue do not produce α-amylase in response to gibberellic acid (GA3) if the incubation temperature is left at 25°C. However, pre-treatment of the protoplast preparation at temperatures above 27°C for at least 8 h followed by a short incubation at 25°C induces sensitivity to the growth regulator such that α-amylase is produced. The requirements of the sensitisation process are similar to those for intact aleurone tissue although additional adjustment to the calcium ion is beneficial. Pre-treatment of aleurone layers with the sensitising temperature regimes prior to protoplast isolation have the advantage of increasing protoplast viability. Once sensitised, the protoplasts respond to a GA3 concentration as low as 10-11 mol dm-3 with a maximal response at 10-9 mol dm-3. The successful isolation of wheat aleurone protoplasts whose sensitivity to GA3 can be manipulated represents a useful step towards investigating the role of cell membranes in growth-regulator action. 相似文献
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Jelsema Carole L.; Ruddat Manfred; Morr? D. James; Williamson Francis A. 《Plant & cell physiology》1977,18(5):1009-1019
A subcellular fraction enriched in aleurone grains isolatedin glycerol from aleurone layers of wheat endosperm specificallyand reversibly bound GA1-(3H). Specific binding of GA1 to otherfractions including spherosomes, nuclei, mitochondria, and plasmamembranes was negligible. The Kd of binding to aleurone grainswas 1.5 µM and the number of specific binding sites 0.45pmoles per mg protein. The presence of Ca++ ions was absolutelyrequired for binding. Abscisic acid which inhibits giberellinaction in vivo prevented specific GA1-binding in vitro. GA1-bindingto aleurone grains is important to the primary action of thehormone which may involve mobilization of reserves from thealeurone grain-spherosome complex for utilization in membranebiogenesis.
1 Present address: Section of Cytology, Yale University Schoolof Medicine, New Haven, CT 06510, U.S.A.
3 Present address: Laboratoire de Biologie V?g?tale, Ecole NormaleSup?rieure, 24 rue Lhomond, 75231 Paris, France. (Received March 28, 1977; ) 相似文献
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Cultured oat (Avena sativa L. — naked form) aleurone protoplasts were employed as a model system for following changes which accompany the development of vacuoles during in-vitro incubation. Over a 5-d period, the aleurone grains progressively grew and fused to form a large central vacuole and the volume of the protoplasts increased sevenfold. The growth of the vacuole was accompanied by a progressive acidification of the vacuolar sap. Vacuolation was inhibited by high concentrations of mannitol and by cycloheximide and cordycepin applied at various times during the incubation period. Neither cycloheximide nor cordycepin affected the initial phases of vacuolation but cycloheximide retarded subsequent stages, particularly if added early in the incubation. Cordycepin inhibited only the later stages of vacuolation. Radiolabelling studies identified at least three novel microsomal proteins, with relative molecular masses of approximately 34, 47 and 48 kDa, which appeared during vacuolation and whose synthesis was markedly affected by these inhibitors.Abbreviations CF
carboxyfluorescein
- CFDA
6 carboxyfluorescein diacetate
- TIP
tonoplast intrinsic protein
We are grateful to Dr Richard Hooley and Dr Robert Walker (Long Ashton Research Station) for providing the methodology for aleurone protoplast isolation and to Professeur Francis Marty (Université de Bourgogne, Dijon) for providing antibodies to the red beet TIP. IACR receives grant-aided support from the Biotechnology and Biological Sciences Research Council of the United Kingdom. 相似文献
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Rapid gibberellin responses and the action of adenosine 3',5'-monophosphate in aleurone layers 总被引:5,自引:0,他引:5
C J Pollard 《Biochimica et biophysica acta》1971,252(3):553-560