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1.
The fate of [ 14C] gibberellin A 3 and [ 3H] gibberellin A 1 was examined in senescing fruit of Shamouti orange ( Citrus sinensis L. Osbeck) and tomato ( Lycopersicon esculentum Mill.). Gibberellin A 3 was highly persistent in Citrus peel (t 1/2=18 days) and to a lesser degree in tomato (t 1/2=5.5 days). Ethylene and ethephon caused a slight enhancement of gibberellin A 3 metabolism in Citrus and tomato fruit, respectively. Gibberellin A 1 was metabolized by Citrus peel at a relatively high rate (t 1/2 < 24 h) and ethylene slightly reduced this rate. It is concluded that the ethylene-induced enhancement of senescence does not involve major effects on the deactivation of applied gibberellins.Abbreviations GA 3
gibberellin A 3
- GA 1
gibberellin A 1 相似文献
2.
Gibberellins A 1, A 8, A 20 and A 29 were identified by capillary gas chromatography-mass spectrometry in the pods and seeds from 5-d-old pollinated ovaries of pea ( Pisum sativum cv. Alaska). These gibberellins were also identified in 4-d-old non-developing, parthenocarpic and pollinated ovaries. The level of gibberellin A 1 within these ovary types was correlated with pod size. Gibberellin A 1, applied to emasculated ovaries cultured in vitro, was three to five times more active than gibberellin A 20. Using pollinated ovary explants cultured in vitro, the effects of inhibitors of gibberellin biosynthesis on pod growth and seed development were examined. The inhibitors retarded pod growth during the first 7 d after anthesis, and this inhibition was reversed by simultaneous application of gibberellin A 3. In contrast, the inhibitors, when supplied to 4-d-old pollinated ovaries for 16 d, had little effect on seed fresh weight although they reduced the levels of endogenous gibberellins A 20 and A 29 in the enlarging seeds to almost zero. Paclobutrazol, which was one of the inhibitors used, is xylem-mobile and it efficiently reduced the level of seed gibberellins without being taken up into the seed. In intact fruits the pod may therefore be a source of precursors for gibberellin biosynthesis in the seed. Overall, the results indicate that gibberellin A 1, present in parthenocarpic and pollinated fruits early in development, regulates pod growth. In contrast the high levels of gibberellins A 20 and A 29, which accumulate during seed enlargement, appear to be unnecessary for normal seed development or for subsequent germination.Abbreviations GA (a)
gibberellin A n
- GC-MS
combined gas chromatography-mass spectrometry
- HPLC
high-performance liquid chromatography
- PFK
perfluorokerosene
- PVP
polyvinylpyrrolidone 相似文献
3.
Gibberellin A 1-3,4- 3H was prepared by selective catalytic reduction of gibberellic acid with a mixture of tritium and hydrogen. 3H-GA 1 was applied at physiological concentrations to dwarf peas and the metabolism of the hormone was investigated. 3H-GA 1 was converted to an acidic, biologically active compound. Radioactive but biologically inactive compounds were also found in the neutral fraction and could not be converted to acidic gibberellins by hydrolysis. No attachment of gibberellin to any macromolecular fraction was evident. 相似文献
4.
The role and source of gibberellins (GAs) involved in the development of parthenocarpic fruits of Pisum sativum L. has been investigated. Gibberellins applied to the leaf adjacent to an emasculated ovary induced parthenocarpic fruit development on intact plants. The application of gibberellic acid (GA 3) had to be done within 1 d of anthesis to be fully effective and the response was concentration-dependent. Gibberellin A 1 and GA 3 worked equally well and GA 20 was less efficient. [ 3H]Gibberellin A 1 applied to the leaf accumulated in the ovary and the accumulation was related to the growth response. These experiments show that GA applied to the leaf in high enough concentration is translocated to the ovary. Emasculated ovaries on decapitated pea plants develop without application of growth hormones. When [ 3H] GA 1 was applied to the leaf adjacent to the ovary a substantial amount of radioactivity accumulated in the growing shoot of intact plants. In decapitated plants, however, this radioactivity was mainly found in the ovary. There it caused growth proportional to the accumulation of CA 1. Application of LAB 150978, an inhibitor of GA biosynthesis, to decapitated plants inhibited parthenocarpic fruit development and this inhibition was counteracted by the application of GA 3 (either to the fruit, or the leaf adjacent to the ovary, or through the lower cut end of the stem). All evidence taken together supports the view that parthenocarpic pea fruit development on topped plants depends on the import of gibberellins or their precursors, probably from the vegetative aerial parts of the plant.Abbreviations FW
flesh weight
- GA n
gibberellin A n
- HPLC
high-performance liquid chromatography 相似文献
5.
The relationship among gibberellins, CCC, vernalization, and photoperiod in the flowering response of radish, Raphanus sativus L., cv. Miyashige-sofuto, was studied. The optimal condition for flowering was vernalization and a 16-hour photoperiod; GA 3 had no additional effect. Gibberellin A 3 (60 μg total) was not able to induce flowering in nonvernalized plants grown on 8-hour days, but it did increase the percentage of nonvernalized plants that flowered under long days from 60 to 100. Gibberellin content of vernalized seedlings increased within the first 24 hours after seedlings were transferred to the greenhouse. Content reached a peak in the first 4 days after transfer and thereafter remained constant. Essentially no gibberellin was found in 2 day-old non-vernalized (control) seedlings of comparable size to the vernalized ones. Gibberellin content in the controls reached a peak on the fourth day of growth in the greenhouse; thereafter, it decreased steadily. Bolting was inhibited slightly by CCC when applied during vernalization; it was almost completely inhibited when CCC was applied after seed vernalization. Extraction experiments revealed that CCC actually reduced the gibberellin content when applied during or after vernalization. The dwarfing agent, however, had essentially no effect on flowering. We concluded that gibberellins likely play a direct role in bolting of `Miyashige-sofuto' radish, but probably are not directly functional in initiating flowering. 相似文献
6.
By combined gas chromatography-mass spectrometry the gibberellin present in suspensors of heart-shaped embryos of Phaseolus coccineus has been identified as Gibberellin A 1 (GA 1). The amount of GA 1 in 2000 suspensors (452 mg), as estimated by gas chromatography. was 4g. The presence of GA 1 in suspensors of P. coccineus is discussed in relation to our present knowledge of the occurrence of many gibberellins in developing seeds and immature fruits of the same species.Abbreviations FID
flame ionization detector
- GA
gibberellin
- GC
gas chromatography
- MS
mass spectrometry
- PGC
preparative gas chromatography
- Stage A
heart-shaped embryo
- Stage B
cotytedonary embryo
- TMS
trimethylsilyl 相似文献
7.
Gibberellin A 17, abscisic acid, and 4′-dihydrophaseic acid were identified by GC-MS of derivatized extracts from both immature and mature seeds of pear. Immature seeds also contained phaseic acid, gibberellins A 25 and A 45, and two presumed mono-hydroxylated derivatives of GA 45, one of which was tentatively identified as 3β-hydroxy-GA 45. Several presumed metabolites of abscisic acid were detected in both mature and immature seeds. 相似文献
8.
Gibberellins A 19, A 20, and A 1 were applied to seedlings of birch ( Betula pubescens Ehrh.) and alder ( Alnus glutinosa (L.) Gaertn.) in order to test their ability to counteract growth inhibition induced by growth retardants (ancymidol and BX-112) or short day (SD, 12 h) photoperiod. Ancymidol inhibits early and BX-112 inhibits late steps in gibberellin biosynthesis. BX-112 inhibited stem elongation in both species while ancymidol, applied as a soil drench, was effective in alder only. Growth retardants affected stem elongation mainly by inhibiting elongation of internodes. All three gibberellins were equally active when applied to seedlings treated with ancymidol; however, only GA 1 was able to counteract the growth inhibition induced by BX-112. SD-induced cessation of elongation growth in birch was counteracted by GA 1, and to some degree, by GA 20, while GA 19 was inactive. SD treatment did not induce cessation of apical growth in alder. These results are consistent with the hypothesis that of gibberellins belonging to the early C-13 hydroxylation pathway, GA 1 is the only active gibberellin for stem elongation. 相似文献
9.
Through the use of a single gene dwarf mutant of Zea mays L., dwarf-1, the interaction of growth retardants with gibberellin biosynthesis was studied in Fusarium monitiforme. It was demonstrated that the growth retardants 2-isopropyl-4-dimcthylamine-5-methyphenyl-1-piperidine-cai'boxylate methyl chloride (Amo 1618) and (2-chloroethyl) trimethylammonium chloride (CCC) are more effective inhibitors of gibberellin biosynthesis in cultures maintained under continuous illumination. Light grown cultures produced significantly more biologically active gibberellin-like materials than dark grown cultures. Stock cultures exposed to light also promoted the subsequent biosynthesis of gibberellins in the dark. Chromatographical analysis of the soluble gibberellins extracted from the culture medium revealed that large amounts of chromatographically detectable A 3 and A 7 were produced in light cultures with only A 7 produced in the dark. Light also induced a greater incorporation of acelate-2- 14C into the gibberellins A 7, A 3 and an unidentified gibberellin. Growth returdants occasionally caused a complete disappearance of chromatographically detectable gibberellins in the dark; however, in the light at no concentration tested was it possible to detect the complete disappearance of gibberellin-like material. A 3 was always detectable. Like higher plants, different strains of F. moniliforme exhibit variation which makes them more or less sensitive to the growth retardants. This variation is interpreted to mean that there may be more than one pathway leading to the synthesis of the gibberellins. 相似文献
10.
When grown on PDL medium for 11 days the strain REC-193A of Gibberella fujikuroi produces the usual range of gibberellins and ent-kaurenoid metabolites. After 3–5 days under the same conditions of culture, this slow growing strain produces virtually none of these metabolites. These short term cultures were found to convert gibberellin A 12-aldehyde into gibberellins A 12 (8.3 % A 14 (45%), A 4 ( ca. 17%) and A 7 ( ca. 6%). Under identical conditions of culture gibberellin A 12 was largely unmetabolised. These results show that 3-hydroxylation is the first step in the conversion of gibberellin A 12-aldehyde into gibberellins A 14, A 4 and A 7. 相似文献
11.
The persistence of gibberellin A 3 on plant surfaces was examined using fruit of Marsh seedless grapefruit ( Citrus paradisi Macf.) and an inert glass model system. 14C-gibberellin A 3 was applied to surfaces in aqueous treatment solutions or in waxing solutions. Dried-out treatment residues were removed by washing and analyzed for total and GA 3-like radioactivity. Gibberellin A 3 persisted without significant loss for at least 7 d in aqueous treatment solutions (pH 4.0 or 6.2) but was less persistent in the pH 10.4 waxing solution ( t1/2=7 d).Loss of total peel surface radioactivity was fast during the first 3 days, slowing down afterwards. After 14 days 73% of the initial radioactivity could still be recovered from fruit peel surface and 70% of the recovered radioactivity was still in the form of gibberellin A 3. Gibberellin A 3 was somewhat more persistent in residues from pH 4 than pH 7 treatment solutions. Light had a slight enhancing effect on gibberellin A 3 decomposition on fruit peel under growth chamber conditions. After 12 d at 100% relative humidity, 88% of the radioactivity on glass surfaces was still in the form of gibberellin A 3, as against 45% at a relative humidity of 50%. Simulated field conditions, combining daily fluctuations in light, temperature and relative humidity, markedly enhanced gibberellin A 3 decomposition on glass surfaces ( t1/2=2 d). Gibberellin A 3 was very persistent (90% after 9 d) in the waxing residues on fruit peel surface.Abbreviations GA 3
gibberellin A 3
- RH
relative humidity 相似文献
12.
Pretreatment effects of different gibberellins, helminthosporicacid, cyclic AMP and Kinetin on subsequent IAA-induced elongationwere tested in cucumber hypocotyl sections. Gibberellin A 7 wasmore active than GA 3, while gibberellin A 3 was almost inactive.Both helminthosporic acid and cyclic AMP mimicked GA 3-action,though the degree of their activity was less. Kinetin pretreatmentresulted in marked inhibition of IAA-induced elongation. Thepretreatment effect of GA 3 was also reflected in a greater responceof the sections to synthetic auxins. (Received October 6, 1973; ) 相似文献
13.
The effects of gibberellin A 3 (GA 3) application on five white clover populations was assessed in both glasshouse and controlled environments. Daylength, temperature and GA 3 interactions were also examined. Gibberellin A 3 did not induce vegetative plants to flower when daylength and temperature requirements were not met. In flowering plants, GA 3 increased the number of reproductive buds per stolon and peduncle length, but did not affect other floral characters. Gibberellin A 3 depressed total stolon numbers, but increased the number of nodes per stolon, internode length, leaf area and petiole length. 相似文献
14.
Summary Gibberellin A 14 and kaurene, precursors of gibberellin A 3, are active in the barley endosperm reducing-sugar assay, but require longer incubation periods for activity to be observed than does GA 3. This finding shows that the incubation period must be considered when determining whether a compound is active in this assay. The longer incubation periods required by GA 14 and kaurene may reflect reduced rates of penetration, or reduced activity within the cell, or the time required for conversion to a physiologically active form. 相似文献
15.
Gibberellin A 13 7-aldehyde, previously proposed as an intermediate in the fungal biosynthesis of gibberellin A 3, has been prepared from gibbere 相似文献
16.
Growth parameters were determined for tall ( rht3) and dwarf ( Rht3) seedlings of wheat ( Triticum aestivum L.). Plant statures and leaf length were reduced by 50% in dwarfs but root and shoot dry weights were less affected. Leaves of dwarf seedlings had shorter epidermal cells and the numbers of cells per rank in talls and dwarfs matched the observed relationships in overall length. Talls grew at twice the rate of dwarfs (2.3 compared with 1.2 mm h -1). [ 3H]Gibberellin A 1 ([ 3H]GA 1) was fed to seedlings via the third leaf and metabolism was followed over 12 h. Immature leaves of tall seedlings transferred radioactivity rapidly to compounds co-chromatographing with [ 3H]gibberellin A 8 ([ 3H]GA 8) and a conjugate of [ 3H]GA 8, whereas leaves of dwarf seedlings metabolised [ 3H]GA 1 more slowly. Roots of both genotypes produced [ 3H]GA 8-like material at similar rates. Isotopic dilution studies indicated a reduced 2-hydroxylation capacity in dwarfs, but parallel estimates of the endogenous GA pool size, obtained by radioimmunoassay, indicated a 12–15 times higher level of GA in the dwarf immature leaves. Dwarfing by the Rht3 gene does not appear to operate through enhanced, or abnormal metabolism of active gibberellins and the act of GA metabolism does not bear an obligate relationship to the growth response.Abbreviations GA n
gibberellin A n
- HPLC
high-performance liquid chromatography 相似文献
17.
The development of sensitive and specific solid-phase enzyme immunoassays for gibberellic acid and gibberellins A 4 and A 7 is reported. The use of antisera of high apparent affinity (K a over 10 10 l mol -1) in conjunction with alkaline phosphatase-labeled gibberellins allows, with minimum procedural effort, the quantitative determination of sub-picogram amounts of these gibberellins. The assays reported here are applicable to most gibberellins and can be set up with 1–1.5 mg of starting material. They represent the most sensitive methods for gibberellin determination known.Abbreviations GA
gibberellin
- GA 3
gibberellic acid
- TLC
thin-layer-chromatography 相似文献
18.
Two long days induced some flowering and 4 or more long days caused 100% flowering in Silene armeria. On long days microscopically detectable flower primordia were first seen after 6 days, which is at least 1 day before the start of stem elongation. Both gibberellin A 3 and A 7 caused flowering on short days, but the results were variable and flowering was never 100%. Three different gibberellins were detected in Silene extracts. The pattern of gibberellins extracted from plants on short and long days was qualitatively the same, but on long days gibberellin content was up to 100% higher than on short days. Only small amounts of diffusible gibberellins were obtained from Silene shoot tips (including very young leaves) on short days. However, on long days the diffusible gibberellins increased by as much as 10-fold after 4 to 6 long days but then declined somewhat after 10 long days. The gibberellins extracted from the shoot tips at the completion of the diffusion period also increased under long days, although the increase was not as large as for the diffusible gibberellins. An A 5-like gibberellin present in extracts was not detected in diffusates. 相似文献
19.
Dwarf cultivar Progress No. 9 and normal cultivar Alaska of Pisum sativum L. were grown under conditions of darkness orred light. Red light decreased the stem elongation rate of bothcultivars. Gibberellins present during the linear phase of stemelongation were isolated and the two main components were tentativelyidentified by gas chromato-chromatography and mass spectrometryas Gibberellin A 1 and A 5. Both gibberellins varied quantitativelywithin and between cultivar and treatment groups, and the amountspresent were inversely related to stem elongation rate. Althoughthe stem elongation rate of plants grown under red light wasrepressed, endogenous gibberellin was not limiting and was asmuch as two-fold higher in red light-grown plants than in dark-grownplants. The levels of endogenous gibberellin in dawrf plantsindicated that the genetic growth limitation was not due toa gibberellin deficiency. (Received May 26, 1981; Accepted January 28, 1982) 相似文献
20.
Gibberellin A 4 was identified by combined gas chromatography-mass spectrometry in the culture medium of , a fungus known to cause the “superelongation disease” of cassava . Gibberellin A 4 was synthesized in ageing cultures and reached concentrations as high as 400 μg/l nutrient broth. After is the second phytopathogenic fungus known with certainty to produce an active gibberellin in considerable amounts. 相似文献
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