Gibberellins Determination, Fluorometric Assay for Gibberellic Acid.

Theriault, Robert J.; Friedland, W. C.; Peterson, M. H.; Sylvester, J. C.

doi:10.1021/jf60113a006

Cited by 18 publications

(7 citation statements)

References 3 publications

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“…T h e balanced phase was a period of proliferation which lasted until the exhaustion was based on the production (7) of a fluorphor by reaction between gibberellic acid and sulphuric acid. Similar procedures were subsequently described in the literature (8,12,24), but as this method differs in detail from these it is described here. The reaction is carried out in 1 : 1 redistilled ethylalco11ol:A.R.…”

Section: Introductionmentioning

confidence: 99%

The Kinetics of Metabolism of Gibberella Fujikuroi in Stirred Culture

Borrow¹,

Brown²,

Jefferys³

et al. 1964

Can. J. Microbiol.

101

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Some aspects are described of tlie kinetics of the groivth of (;ibbeie!la fzljik~~ro?:in nitrogen-limited media contai~ling either am~uonium nitrate, ammonium acetate, ammonium tartl-ate, urea, or glycine. Also varied were inoculum size, agitation rate, pI-I, and initial concentrations of glucosc and nitrogen source. The sigiiihcance of kinetic parameters ~lsed in this, and published studies, is discussed.A lag phase n:as only found on ammonium acetate media or when higli concentrations of glucose \\,ere present. Early gro\vth was exponei~tial on all nitrogen sources. On ammonium acetate the specilic growth rate decreased a t a dry weight ofca. 1 mg/g WS (Whole ~~nliltered Samplc). On arnmol~iuin nitrate, early expoiientiaI growth ~~t i l i z e d more NI-13-nitrogen than NOJ-l~itrogen \vith a corlcornitant decrease in pH. I n the range pH 3.0-2.8 NHa-nitrogen uptalre and dry weight increase ceased, but SOs-nitrogen uptalce continued, and the pH increased until growth and NI-I:,-nitrogen uptalce restarted. 'This pattern could be repeated. Finally, expo~lential growth was resumed a t a lo\\, specilic gro\\.th rate. On gIycine, urea, and ammoni~lm tartrate media, exponel~tial growth continned to a dry weight of about 7 mg/g \VS. During, this pcriod the uptalces relative to dry weight (contributions) of glucose, nttrogen, phosphate, and magnesium remained coilstant and were unaffected by the rate of agltatloll, as also was the specihc growth rate, but the latter decreased with increasing glucose concentration.A period of linear growth could folio\\, the exponential period. The contribution bf glucose was ireater, and that of phosphate and magnesium less, than during exponential growth. The dry weight a t which espol~ential growth changed to linear growth \\.as greater the higher the rate of agitation, and this change may be a response to oxygen restriction. After nitrogen exhaustion, fat and carbohydrate accum~llntion in tlie cells largely accour~ted for the increase in dry weight. The specilic rates of dry weight increase and glucose uptake remained constant over the lower range of initial nitrogen concentrations. Both rates decreased with increasing nitrogen over the higher range.Gibberellic acid production began a t , or soon after, nitrogen exhaustion. The amount present increased lirlearly with time. The productivity decreased with increasing glucose conce~~tration; and first increased and then decreased with increasing initial nitrogen. 'I'he maximum amount produced was proportional to the initial nitrogen provided. Some published results are discussed in the light of these relations.

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Section: Introductionmentioning

confidence: 99%

The Kinetics of Metabolism of Gibberella Fujikuroi in Stirred Culture

Borrow¹,

Brown²,

Jefferys³

et al. 1964

Can. J. Microbiol.

101

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“…Several methods for the determination of gibberellins have been developed. These include fluorometric procedures (9,13,35), the isotopic dilution method (18,19,22), gas chromatography (4,10), and bioassay with dwarf rice seedlings (21), deembryonated barley endosperm (1,12,26,38), dwarf peas 7, and cucumber seeds (16). Among these methods, the bioassay method, which depends on the biological activity of gibberellins, is most selective, but the bioassay results are not consistent.…”

Section: Retention Time (Min)mentioning

confidence: 99%

Determination of Endogenous Gibberellins in Germinating Barley by Combined Gas Chromatography-Mass Spectrometry

1982

ASBCJ

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This study was undertaken to elucidate the dominant endogenous gibberellins (GA) and the changes in their levels in germinating barley during malting. Also, a method for determining gibberellins in barley and malt by combined gas chromatography-mass spectrometry (GC-MS) was developed. Endogenous gibberellins in germinating Fuji Nijo II and Betzes barley were sequentially extracted with ethanol and ethyl acetate. Fractions corresponding to GAi, GAj, GA 4 , and GA? were separated and collected from the ethyl acetate extract by Sephadex LH-20 column chromatography, silicic acid partition column chromatography, silica gel thin-layer chromatography, and kieselguhr thin-layer chromatography. Biological activity of each fraction was examined by bioassay with dwarf rice seedlings (var. Tan-ginbozu) and deembryonated barley endosperm. Identification of each gibberellin was performed by analysis of the methyl ester trimethylsilyl ether derivative of gibberellin in each fraction by GC-MS. Determination of gibberellin content was performed by mass fragmentography with GC-MS. The data indicated that the dominant gibberellin in germinating barley is GAi and that G Aj is a minor gibberellin. GA< and GA? were not identified. GAi and GAj contents in germinating barley under malting conditions reached their maximum concentrations on the second day; levels decreased on the fourth and sixth days of germination. The behavior of authentic GAs added to steeped barley during germination and the contents of residual GAs in commercial malts were also examined.

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“…Their use was made possible by the development of toxic, chlorinated hydrocarbon insecticides that are stable in the soil and reasonably stable in mixtures with fertilizers. The latest data available indicate that 109,956 tons, equivalent to 0.74% of all mixed fertilizers, were used in the United States in the year ending June 30, 1956 (6).…”

Section: Fertilizer-pesticide Mixturesmentioning

confidence: 99%

“…The extremely low, effective concentrations, coupled with the relatively poor chemical stability of the gibberellins, have made detailed studies difficult. Of the various analytical methods, only fluorometric assay (6) and bioassay (4) are sensitive enough to operate at natural levels. However, neither method lends itself readily to distinguish between the various gibberellins or gibberellin-like substances, or to quantitative work within the part per billion range.…”

mentioning

confidence: 99%