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1.
Summary The main gibberellin in immature seed of Pisum sativum L., cv. Alaska, is identified as GA20 by GC-MS. GA9 may also be present.  相似文献   
2.
Seventeen desert tortoises, Xerobates agassizii, with upper respiratory tract disease were examined; thirteen were euthanatized for necropsy. Four normal control desert tortoises from a clinically healthy population were similarly evaluated. Hemoglobin and phosphorus values were significantly (P less than or equal to 0.05) lower and serum sodium, urea, SGOT, and cholesterol values were significantly higher in ill tortoises compared to controls. No significant differences in concentrations of serum or liver vitamins A and E were found between the two groups. While no significant differences were found for concentrations of lead, copper, cadmium, and selenium, the livers of ill tortoises had higher concentrations of mercury and iron. Lesions were found consistently in the upper respiratory tract (URT) of ill tortoises. In all ill tortoises dense infiltrates of lymphocytes and histiocytes obscured the mucosal epithelium and underlying glands. The mucosal epithelium was variably dysplastic, hyperplastic, and occasionally ulcerated. Electron microscopic studies revealed small (350 to 900 nm), pleomorphic organisms resembling Mycoplasma sp., in close association with the surface epithelium of the URT of ill tortoises. Pasteurella testudinis was cultured from the nasal cavity of all ill tortoises and one of four control tortoises. A Mycoplasma sp. was cultured from the nasal passageways of four ill tortoises and was ultrastructurally similar to the pleomorphic organism present on the mucosa in tissue section.  相似文献   
3.
Gibberellins (GAs) A17, A19, A20, A29, A44, 2OH-GA44 (tentative) and GA29-catabolite were identified in 21-day-old seeds of Pisum sativum cv. Alaska (tall). These GAs are qualitatively similar to those in the dwarf cultivar Progress No. 9 with the exception of GA19 which does not accumulate in Progress seeds. There was no evidence for the presence of 3-hydroxylated GAs in 21 day-old Alaska seeds. Dark-grown shoots of the cultivar Alaska contein GA1, GA8, GA20, GA29, GA8-catabolite and GA29-catabolite. Dark-grown shoots of the cultivar Progress No.9 contain GA8, GA20, GA29 and GA29-catabolite, and the presence of GA1 was strongly indicated. Quantitation using GAs labelled with stable isotope showed the level of GA1 in dark-grown shoots of the two cultivars to be almost identical, whilst the levels of GA20, GA29 and GA29-catabolite were significantly lower in Alaska than in Progress No. 9. The levels of these GAs in dark-grown shoots were 102- to 103-fold less than the levels in developing seeds. The 2-epimer of GA29 is present in dark-grown-shoot extracts of both cultivars and is not thought to be an artefact.Abbreviations cv cultivar - GAn gibberellin An - GC gas chromatography - GC-MS combined gas chromatographymass spectrometry - HPLC high-pressure liquid chromatography - KRI Kovats retention index - MeTMSi methyl ester trimethylsilyl ether  相似文献   
4.
The GA20 3β-hydroxylase present in immature seeds of Phaseolus vulgaris has been partially purified and characterized. The physical characteristics of the enzyme are similar to those of the GA 2β-hydroxylases present in mature and immature seeds of Pisum sativum. It is acid-labile, hydrophobic, and of Mr 45,000. The enzyme catalyzes the synthesis of GA1, GA5, and GA29 from GA20. Activity is dependent upon the presence of Fe2+, ascorbate, 2-oxoglutarate, and oxygen. 2-Oxoglutarate does not function as a cosubstrate; in the presence of the enzyme, succinate is not a reaction product.  相似文献   
5.
[17-13C,3H]-Labeled gibberellin A20 (GA20), GA5, and GA1 were fed to homozygous normal (+/+), heterozygous dominant dwarf (D8/+), and homozygous dominant dwarf (D8/D8) seedlings of Zea mays L. (maize). 13C-Labeled GA29, GA8, GA5, GA1, and 3-epi-GA1, as well as unmetabolized [13C]GA20, were identified by gas chromatography-selected ion monitoring (GC-SIM) from feeds of [17-13C, 3H]GA20 to all three genotypes. 13C-Labeled GA8 and 3-epi-G1, as well as unmetabolized [13C]GA1, were identified by GC-SIM from feeds of [17-13C, 3H]GA1 to all three genotypes. From feeds of [17-13C, 3H]GA5, 13C-labeled GA3 and the GA3-isolactone, as well as unmetabolized [13C]GA5, were identified by GC-SIM from +/+ and D8/D8, and by full scan GC-MS from D8/+. No evidence was found for the metabolism of [17-13C, 3H]GA5 to [13C]GA1, either by full scan GC-mass spectrometry or by GC-SIM. The results demonstrate the presence in maize seedlings of three separate branches from GA20, as follows: (a) GA20 → GA1 → GA8; (b) GA20 → GA5 → GA3; and (c) GA20 → GA29. The in vivo biogenesis of GA3 from GA5, as well as the origin of GA5 from GA20, are conclusively established for the first time in a higher plant (maize shoots).  相似文献   
6.
Cell-free preparations from seeds of Marah macrocarpus L. and Malus domestica L. catalyzed the conversion of gibberellin A9 (GA9) and 2,3-dehydroGA9 to GA7; GA9 was also metabolized to GA4 in a branch pathway. The preparation from Marah seeds also metabolized GA5 to GA3 in high yield; GA6 was a minor product and was not metabolized to GA3. Using substrates stereospecifically labeled with deuterium, it was shown that the metabolism of GA5 to GA3 and of 2,3-dehydroGA9 to GA7 occurs with the loss of the 1β-hydrogen. In cultures of Gibberella fujikuroi, mutant B1-41a, [1β,2β-2H2]GA4, was metabolized to [1,2-2H2]GA3 with the loss of the 1α- and 2α-hydrogens. These results provide further evidence that the biosynthetic origin of GA3 and GA7 in higher plants is different from that in the fungus Gibberella fujikuroi.  相似文献   
7.
The levels of GA1, 3-epiGA1 and GA8 in genotypes Le, le and led of Pisum sativum L. were determined by gas chromatography-selected ion monitoring (GC-SIM) after feeds of [3H, 13C]-GA20 to each genotype. The levels of endogenous and [13C]-labelled metabolites were determined by reverse isotope dilution with unlabelled GA1, 3-epiGA1 and GA8. The results demonstrate a quantitative relationship between the level of GA1 and the extent of elongation both on a per plant and a per g fresh weight basis. These results are consistent with previous findings in peas and other species possessing a predominant early 13-hydroxylation pathway for GA biosynthesis.
The levels of 3-epiGA1 also decreased in the genotypic sequence Le, le, led although not as rapidly as for the level of GA1. This may suggest that the alleles at the le locus also influence the formation of 3-epiGA1.  相似文献   
8.
9.
Gibberellins A1, A4, A9, A12-aldehyde, A20 and A51, each labelled with both a radioactive and stable isotope were fed to immature barley grain by injection into the endosperm. After 7 d, extensive metabolism of all substrates had occurred, and metabolites were identified by combined capillary gas chromatography-mass spectrometry. A proposed scheme of gibberellin metabolism in immature barley grain is presented.Abbreviations GAn gibberellin An - GC-MS combined gas chromatography-mass spectrometry - HPLC high-performance liquid chromatography  相似文献   
10.
The concentrations of endogenous gibberellin (GA) 1, 5, 8, 19, 20, and 29 in the component tissues of maturing tall (Le) and dwarf (le) pea (Pisum sativum) plants have been determined. The following conclusions were drawn from the data obtained: (a) GA20 and its metabolites accumulate only in the growing regions of Le and le plants; (b) the le mutation is biochemically expressed in all immature tissues of the dwarf plants; (c) the quantitative composition of the GA metabolites in the various immature tissues is variable; (d) the total GA concentration in apical buds, unexpanded leaves, and tendrils is considerably higher than in GA1-responsive stem tissue; and (e) there is very little GA accumulation of the inactive 2β-hydroxylated GAs (GA8 and GA29) in either the mature vegetative tissues or the roots of pea plants.  相似文献   
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