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1.
The biosynthetic steps from gibberellin A12-aldehyde (GA12-aldehyde) to C19-GAs were studied by means of a cell-free system from the embryos of immature Phaseolus vulgaris seeds. Stable-isotope-labeled GAs were used as substrates and the products were identified by gas chromatography-mass spectrometry. Gibberellin A12-aldehyde was converted to GA4 via non-hydroxylated intermediates and to GA1 via 13-hydroxylated intermediates. 13-Hydroxylation took place at the beginning of the pathway by the conversion of GA12-aldehyde to GA53-aldehyde. The conversion of GA20 to GA5 and GA6 was also shown but no 2-hydroxylating activity was found. Endogenous GAs from embryos and testas of 17-dold seeds were re-examined by gas chromatography-selected ion monitoring using stable-isotopelabeled GAs as internal standards. Gibberellins A9, A12, A15, A19, A23, A24, and A53 were identified for the first time in P. vulgaris, in addition to GA1, GA4, GA5, GA6, GA8, GA17, GA20, GA29, GA37, GA38 and GA44, which were previously known to occur in this species. The levels of all GAs, except the 2-hydroxylated ones, were greater in the embryos than in the testas. Conversely, the contents of GA8 and GA29, both 2-hydroxylated, were much higher in the testas than in the embryos.Abbreviations GAn gibberellin An - GC-MS gas chromatography-mass spectrometry - GC-SIM gas chromatography-selected ion monitoring - HPLC high-performance liquid chromatography - TLC thin-layer chromatography - m/z ion of mass  相似文献   

2.
3.
A very sensitive and specific bioassay using prohexadione calcium [BX-112, which blocks 2- and 3-hydroxylation of gibberellins (GAs)] with uniconazole (which blocks oxidation of ent-kaurene, ent-kaurenol and ent-kaurenal) in a microdrop assay was developed for several rice (Oryza sativa L.) varieties, including cv. Waito-C, which is already specific to 3-hydroxylated GAs. The sensitivity and specificity of cvs. Waito-C, Tan-ginbozu and Koshihikari to 3-hydroxylated GAs was greatly enhanced by treatment of the seeds with a combination of 40 mM prohexadione calcium and 80 M uniconazole. The minimum detectable doses of 3-hydroxylated GAs (GA1, GA3, GA4 and GA7) in the three cultivars treated with both chemicals were 1 to 10 fmol (i.e. ca. 350 fg to 3.5 pg) per plant. This is equal to 30-fold more sensitive than Waito-C treated with uniconazole alone, and 30 to 1000-fold more sensitive than Waito-C with no growth retardant soak. Minimum detectable doses of 3-nonhydroxylated GAs (GA9, GA19 GA20) and GAs with very low biological activity (GA8 and GA17) were equal to or more than 1000 fmol per plant. This is about equal to the activity in Waito-C treated with uniconazole alone. Application of this assay to an extract from Raphanus sativus was compared with the data by gas chromatography/mass spectrometry (GC/MS), confirming the conclusions reached using authentic test GAs, namely that use of uniconazole plus BX-112 appreciably enhanced the detection sensitivity to fractions shown by GC/MS to contain GA1 and GA4, both 3-hydroxylated GAs.Abbreviations GA gibberellin - BX-112 prohexadione calcium  相似文献   

4.
GA17, GA19, GA20, GA29, GA44 and 13-hydroxy-GA12, now named GA53, were identified by GC-MS in immature seeds of Vicia faba (broad bean). Also identified were a GA catabolite, two polyhydroxykauranoic acids, and abscisic, phaseic and dihydrophaseic acids. The GAs of Vicia are hydroxylated at C-13, in common with those of other legumes. However the GAs of Vicia are not hydroxylated at C-3, nor do they appear to be readily conjugated. In these respects Vicia resembles Pisum, another member of the tribe Viciae. Vicia differs from Phaseolus and Vigna, of the tribe Phaseoleae, in both these respects.Abbreviations ABA abscisic acid - DPA dihydrophaseic acid - GAn gibberellin An - GC gas chromatography - GC-MS gas chromatography mass spectrometry - KA kauranoic acid - PA phaseic acid - TLC thin layer chromatography  相似文献   

5.
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   

6.
Twenty known gibberellins (GAs) have been identified by combined capillary gas chromatography-mass spectrometry in extracts from less than 10 g fresh weight of maturing seeds of the cucurbit Sechium edule Sw. The GAs are predominantly 3- and-or 13-hydroxylated. This is the first reported identification of non-conjugated 13-hydroxylated GAs in a cucurbit. Gibberellin A8 and gibberellin A8-catabolite are the major GAs in terms of quantity and are largely accumulated in the testa. The catabolites of 2-hydroxylated GAs are ,-unsaturated ketones which no longer possess of a -lactone. They were hitherto known only in legumes. The presence of GA8-catabolite as a major component of Sechium seeds indicates that the distribution of these GA-catabolites may be more widespread than previously envisaged. The localization of known GAs in maturing seeds of the legume Phaseolus coccineus L. was found to resemble closely that in Sechium. Gibberellin A8, a putative conjugate of GA8 and GA8-catabolite are accumulated in the testa. The localization in the testa of end-products of the GA-biosynthetic pathway, which was first observed in maturing seeds of Pisum sativum, and is now described in Phaseolus and Sechium, may be a general feature of seed development.Abbreviations GAn gibberellin An - GC-MS combined gas chromatography-mass spectrometry  相似文献   

7.
Gibberellins (GAs) were identified and quantified during flower and fruit development in the Christmas rose (Helleborus niger L.), a native of southeastern Europe with a long international horticultural tradition. Physiologically, the plant differs from popular model species in two major respects: (1) following anthesis, the initially white or rose perianth (formed in this species by the sepals) turns green and persists until fruit ripening, and (2) the seed is shed with an immature embryo, a miniature endosperm, and a prominent perisperm as the main storage tissue. GA1 and GA4 were identified by full-scan mass spectra as the major bioactive GAs in sepals and fruit. LC-MS/MS system in accord with previously verified protocols also afforded analytical data on 12 precursors and metabolites of GAs. In the fruit, GA4 peaked during rapid pericarp growth and embryo development and GA1 peaked during the subsequent period of rapid nutrient accumulation in the seeds and continued pericarp enlargement. In the sepals, the flux through the GA biosynthetic pathway was highest prior to the light green stage when the photosynthetic system was induced. Unfertilized, depistillated, and deseeded flowers became less green than the seed-bearing controls; chlorophyll accumulation could be restored by applying GA1, GA4, and, less efficiently, GA3 to the deseeded fruit. The sepals of unfertilized and depistillated flowers indeed contained very low levels of GA4 and gradually decreasing levels of GA1. However, the concentrations of their precursors and metabolites were less affected. These data suggest that a signal(s) from the fruit stimulates GA biosynthesis in the sepals resulting in greening. The fruit-derived GAs appear to be mainly involved in pericarp growth and seed development.  相似文献   

8.
Our previous work demonstrated that exogenous gibberellins (GAs) applications during rapid fruit growth significantly increases sink demand and results in a larger fruit in Japanese pear. In an attempt to unravel the mechanism of increased sink demand by applied GAs, the histology, cell wall components of the flesh, and carbon accumulation in the fruit were assessed for Japanese pear (Pyrus pyrifolia, cultivar ‘Kousui’), as were the activities of sucrose- and sorbitol-cleaving enzymes. Our results show that most vascular tissues occurred in core tissue with very little vascular tissue in the flesh. Application of a mixture of GA3 + GA4 in lanolin paste significantly increased the amount of ethanol-insoluble solids, e.g., total pectins, hemicellulose, and cellulose in the cell walls. There was a significantly increased sink demand (assessed by 13C accumulation in the fruit) by the applied GAs, and this increased sink strength was closely related to increased activities of cell wall-bound invertase in the core, neutral invertase and NAD-dependent sorbitol dehydrogenase in the flesh during rapid fruit growth. As well, concentrations of sorbitol and sucrose in the flesh were decreased by GA application, while glucose concentration increased. Most importantly, the fact that sink activity can be increased by GA application implies that endogenous GAs are likely to be important modulators for sugar metabolism. Hence, selecting for genotypes with elevated GA production in the growing fruit and increased activities of key enzymes for sugar metabolism could result in increased fruit size.  相似文献   

9.
The radio-labeled gibberellins GA1, GA3,GA4, and GA7 were applied to intact developing applefruits (Malus domestica Borkh. cv. Jonagold) during theperiod when GAs are suggested to inhibit flower bud induction for the followingyear. Radioactivity from these compounds was found to be transported intoadjacent tissues as there are pedicels and bourses (4%). Application topedicels, after removal of the fruits, enhanced the transport into adjacentbourses up to 11%. The bud-carrying lateral bourse shoots contained onlyminor amounts of radioactivity on average 0.4% in both cases. Theseexport rates were identical, 1 or 5 days after application.After application of the corresponding deuterium-labeled GAs and analyses bymass spectrometry the specific metabolization of GA1 toGA1 13-O-glucoside and of GA3 to GA313-O-glucoside was demonstrated. Additional metabolites of GA1 andGA3 were not detected. After fruit application of GA3 theratio of GA3 to GA3 13-O-glucoside was found to be 1:2 inthe fruit. Pedicel application led to ratios of 1:4 and 1:5, respectively, inthe pedicel and in the adjacent bourse. After the application of GA4and GA7, neither glucosylation products nor other GA-like metabolitescould be identified.This is the first report of the metabolism of GAs to GA 13-O-glucosides indeveloping apple fruits. The possible function of the GAs as a signal in flowerbud formation for the following year is discussed.  相似文献   

10.
Eight rapid-cyclingBrassica genotypes differing in height were treated with gibberellins (GAs) by syringe application to the shoot tip. The height of two genotypes ofBrassica napus, Bn5-2 and Bn5-8, andB. rapa mutants,dwarf 1 (dwf1) anddwarf 2 (dwf2), was unaffected by exogenous GA3 at dosages up to 0.1 g/plant, a level which increased shoot elongation of normal genotypes. Thus, these dwarf mutants are GA-insensitive. In contrast to theB. napus dwarfs, twoB. rapa mutants,rosette (ros), anddormant (dor), elongated following GA3 application. The dwarfros was most sensitive, responding to applications as low as 1 ng GA3/plant. Furthermore,ros also responded to GA1 and some of its precursors with decreasing efficacy: GA3>ent-kaurenoic acid GA1>GA20GA19=GA44GA53. Endogenous GAs were measured by gas chromatography-selected ion monitoring using [2H2]GA internal standards for calibration, from shoots of the GA-insensitive genotypes Bn5-2, Bn5-8 which contained theB. napus mutantdwarf 1, and from a normal genotype Bn5-1. Concentrations of GA1 and GA20 averaged 3.2- and 4.6-fold higher, respectively, and GA19 levels also tended to be higher in the dwarfs than in the normal genotype.  相似文献   

11.
The effects of applied gibberellins (GAs), GA1, GA3, GA4 and GA7 with a cytokinin, N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU) and indole-3-acetic acid (IAA) on fruit set, parthenogenesis induction and fruit expansion of a number of Rosaceae species were assessed. These included Japanese pear cv. ‘Akibae’ (self-compatible) and cv. ‘Iwate yamanashi’ (a seedless cultivar). Other Rosaceae species (Pyrus communis, Chaenomeles sinensis, Cydonia oblonga, and Malus pumila) were also investigated. GA4, GA7 and CPPU are very effective in inducing parthenocarpic fruit growth, whereas GA1, GA3 and IAA, have no ability to induce parthenogenesis in Japanese pear. GA4- and GA7-induced parthenocarpic fruit tended to be smaller in size, higher in flesh hardness, and showed advanced fruit ripening in comparison to pollinated fruit and to parthenocarpic fruit induced by CPPU. GA4- and GA7-induced parthenocarpic fruit also had an increased pedicel length and fruit shape index and also showed a slight protrusion of the calyx end. CPPU, GA4 and GA7 alone or combination with uniconazole were also active in inducing parthenogenesis in three other Rosaceae species, although final fruit set was extremely low. GA1 was essentially inactive in promoting fruit expansion unlike the other bioactive GAs, whose effectiveness in promoting fruit cell expansion was as follow: GA4 ≈ GA7 > GA3 > GA1.  相似文献   

12.
In addition to the previously-reported gibberellins: GA1; GA8, GA20 and GA29 (García-Martínez et al., 1987, Planta 170, 130–137), GA3 and GA19 were identified by combined gas chromatography-mass spectrometry in pods and ovules of 4-d-old pollinated pea (Pisum sativum cv. Alaska) ovaries. Pods contained additionally GA17, GA81 (2-hydroxy GA20) and GA29-catabolite. The concentrations of GA1, GA3, GA8, GA19, GA20 and GA29 were higher in the ovules than in the pod, although, with the exception of GA3, the total content of these GAs in the pod exceeded that in the seeds. About 80% of the GA3 content of the ovary was present in the seeds. The concentrations of GA19 and GA20 in pollinated ovaries remained fairly constant for the first 12 ds after an thesis, after which they increased sharply. In contrast, GA1 and GA3 concentrations were maximal at 7 d and 4–6 d, respectively, after anthesis, at about the time of maximum pod growth rate, and declined thereafter. Emasculated ovaries at anthesis contained GA8, GA19 and GA20 at concentrations comparable with pollinated fruit, but they decreased rapidly. Gibberellins a1 and A3 were present in only trace amounts in emasculated ovaries at any stage. Parthenocarpic fruit, produced by decapitating plants immediately above an emasculated flower, or by treating such flowers with 2,4-dichlorophenoxyacetic acid or GA7, contained GA19 and GA20 at similar concentrations to seeded fruit, but very low amounts of GA1 and GA3 Thus, it appears that the presence of fertilised ovules is necessary for the synthesis of these last two GAs. Mature leaves and leaf diffusates contained GA1, GA8, GA19 and GA20 as determined by combined gas chromatography-mass spectrometry using selected ion monitoring. This provides further evidence that vegetative tissues are a possible alternative source of GAs for fruit-set, particularly in decapitated plants.Abbreviations 2,4-D 2,4-dichlorophenoxyacetic acid - FW fresh weight - GAn gibberellin An - GC-MS combined gas chromatography-mass spectrometry - HPLC high-performance liquid chromatography - KRI Kovats retention index - m/z mass to charge ratio We thank Mr M.J. Lewis for qualitative GC-MS analyses and Ms M.V. Cuthbert (LARS), R. Martinez Pardo and T. Sabater (IATA) for technical assistance. We are also grateful to Professor B.O. Phinney, University of California, Los Angeles, for gifts of [17-13C]GA8 and -GA29 and to Mr Paul Gaskin, University of Bristol, for the mass spectrum of GA29-catabolite and for a sample of GA81 The work in Spain was supported by Dirección General de Investigación Cientifica y Técnica (grant PB87-0402 to J.L.G.-M.). We also acknowledge the British Council and Ministerio de Educacion y Ciencia for travel grants through Accion Integrada Hispano-Britanica 56/142 (J.L.G.-M. and P.H.).  相似文献   

13.
The physiological characteristics of the response of excised cowpea (Vigna sinensis cv Blackeye pea No. 5) epicotyls to gibberellins (GAs) were studied. Epicotyl explants, retaining the petioles and a 2-cm portion of hypocotyl, were placed upright in small vials containing water. Plant growth substances were injected into the subapical tissues as ethanol solutions.Epicotyl elongation resulting from treatment with 0.5 g of GA ranged between 5 and 13 times that of the control, depending on the GA applied. With GA1, no differences were obtained with explants prepared from 5 to 9-day-old seedlings. The increase in elongation could be detected within 6 h of treatment, and the stimulus of a single application lasted at least 4 days. Final elongation was proportional to the logarithm of the amount of GA, applied, 0.01 to lug. The response to GA treatment was limited to the upper part, the most sensitive zone being located between 2 to 4 mm below the apex of the epicotyl; this effect was entirely due to cell elongation.The induction of epicotyl elongation by GAs seems to be specific and independent of the effect of auxin. IAA had no effect on elongation and 4-chloro-phenoxyisobutyric acid (PCIB) did not affect the response to GA1 Abbreviations ABA abscisic acid - GA gibberellin - IAA Indole-3-acetic acid - TIBA 2,3,5-triiodobenzoic acid - PCIB 4-chloro-phenoxyisobutyric acid  相似文献   

14.
Summary The presence of abscisic and phaseic acid in a purified acidic extract from flowering plants of the long-short-day plant Bryophyllum daigremontianum [(R. Hamet and Perr.) Berg.] was conclusively established by combined gas chromatography-mass spectrometry (GC-MS) of their methyl esters. Gibberellin A20 (GA20) was identified by GC-MS of the methyl ester and the trimethylsilyl ether of the methyl ester. The following levels of the 3 compounds per kg fresh weight were estimated: Abscisic acid, 5.5 g; phaseic acid, 9.4g; gibberellin A20, 0.8 g. When GA20 and four other GAs were applied to Bryophyllum under shortday conditions, the order of effectiveness for induction of flower formation was: GA2>GA1>GA5=GA7>GA20. The low biological activity of the native GA20 is discussed.  相似文献   

15.
Gibberellins (GAs) are endogenous hormones that play a predominant role in regulating plant stature by increasing cell division and elongation in stem internodes. The product of the GA 2-oxidase gene from Phaseolus coccineus (PcGA2ox1) inactivates C19-GAs, including the bioactive GAs GA1 and GA4, by 2β-hydroxylation, reducing the availability of these GAs in plants. The PcGA2ox1 gene was introduced into Solanum melanocerasum and S. nigrum (Solanaceae) by Agrobacterium-mediated transformation with the aim of decreasing the amounts of bioactive GA in these plants and thereby reducing their stature. The transgenic plants exhibited a range of dwarf phenotypes associated with a severe reduction in the concentrations of the biologically active GA1 and GA4. Flowering and fruit development were unaffected. The transgenic plants contained greater concentrations of chlorophyll b (by 88%) and total chlorophyll (11%), although chlorophyll a and carotenoid contents were reduced by 8 and 50%, respectively. This approach may provide an alternative to the application of chemical growth retardants for reducing the stature of plants, particularly ornamentals, in view of concerns over the potential environmental and health hazards of such compounds. C. Dijkstra, E. Adams, A. Bhattacharya and A. F. Page contributed equally to this paper.  相似文献   

16.
Sjut  V.  Bangerth  F. 《Plant Growth Regulation》1982,1(4):243-251
Ethylene, indol-3-acetic acid (IAA), gibberellin-like substances (GAs) and abscisic acid (ABA) were analysed in extracts from normal, seed-containing and parthenocarpic tomato fruits throughout fruit development. Parthenocarpic fruit growth was induced with an auxin (4-CPA), morphactin (CME) or gibberellic acid (GA3) and compared with that of pollinated control fruits. Fruit growth was only affected by the treatment with GA3, decreasing size and fresh weight by 60%. The peak sequence of hormones during fruit development was ethylene-GAs-IAA-ABA. Seeded fruits contained the highest levels of IAA and ABA but the lowest levels of GAs. Also, in seeded fruits, a high proportion of IAA and ABA was found in the seeds whereas this was not the case for GAs.Hormone levels of tomato fruits may be successfully, easily and reproducibly altered by inducing parthenocarpic fruit growth and thus eliminating development of seeds which are a major source of hormone synthesis. In spite of markedly changed hormone levels, there was no obvious relationship between fruit growth and extractable hormones per se. However, the results indicate that a high ratio of GAs: auxins is unfavourable for growth of tomato fruits.  相似文献   

17.
J. A. D. Zeevaart 《Planta》1985,166(2):276-279
The effects of the new growth retardant tetcyclacis (TCY) on stem growth and endogenous gibberellin (GA) levels were investigated in the long-day rosette plant Agrostemma githago. Application of TCY (10 ml of a 5·10-5M solution daily) to the soil suppressed stem elongation in Agrostemma grown under long-day conditions. A total of 10 g GA1 (1 g applied on alternate days) per plant overcame the growth retardation caused by TCY.Control plants and plants treated with TCY were analyzed for endogenous GAs after exposure to nine long days. The acidic extracts were fractionated by high-performance liquid chromatography. Part of each fraction was tested in the d-5 maize bioassay, while the remainder was analyzed by combined gas chromatography-selected ion monitoring. The bioassay results indicated that the GA content of plants treated with TCY was much lower than that of untreated plants. The data obtained by gas chromatography-selected ion monitoring confirmed that the levels of seven GAs present in Agrostemma were much reduced in TCY-treated plants when compared with the levels in control plants: GA53 (13%), GA44 (0%), GA19 (1%), GA17 (33%), GA20 (15%), GA1 (4%), and epi-GA1 (13%). These results provide evidence that TCY inhibits stem growth in Agrostemma by blocking GA biosynthesis and thus lowering the levels of endogenous GAs.Abbreviations AMO-1618 2-isopropyl-4-dimethylamino-5-methylphenyl-1-piperidine-carboxylate methyl chloride - GA(s) gibberellin(s) - HPLC high-performance liquid chromatography - TCY Tetcyclacis (5-[4-chlorophenyl]-3,4,5,9,10-pentaaza-tetracyclo-5,4,1,02,6,08,11-dodeca-3,9-diene)  相似文献   

18.
Among the multiple environmental signals and hormonal factors regulatingpotato plant morphogenesis and controlling tuber induction, jasmonates (JAs)andgibberellins (GAs) are important components of the signalling pathways in theseprocesses. In the present study, with Solanum tuberosum L.cv. Spunta, we followed the endogenous changes of JAs and GAs during thedevelopmental stages of soil-grown potato plants. Foliage at initial growthshowed the highest jasmonic acid (JA) concentration, while in roots the highestcontent was observed in the stage of tuber set. In stolons at the developmentalstage of tuber set an important increase of JA was found; however, in tubersthere was no change in this compound during tuber set and subsequent growth.Methyl jasmonate (Me-JA) in foliage did not show the same pattern as JA; Me-JAdecreased during the developmental stages in which it was monitored, meanwhileJA increased during those stages. The highest total amount of JAs expressed asJA+Me-JA was found at tuber set. A very important peak ofJA in roots was coincident with that observed in stolons at tuber set. Also, aprogressive increase of this compound in roots was shown during the transitionof stolons to tubers. Of the two GAs monitored, gibberellic acid(GA3) was the most abundant in all the organs. While GA1and GA3 were also found in stolons at the time of tuber set, noothermeasurements of GAs were obtained for stolons at previous stages of plantdevelopment. Our results indicate that high levels of JA and GAs are found indifferent tissues, especially during stolon growth and tuber set.  相似文献   

19.
Seeds from heavily fruiting (on-year), mature untreated, and paclobutrazol-treated apple trees (Malus domestica Borkh. cv. Spartan) were sampled in mid-June 1987, mid-July 1987, and mid-July 1990. After seeds were freeze-dried, gibberellins (GAs) were extracted, purified, and fractionated via C18 reversed-phase high-performance liquid chromatography (HPLC). Nine GAs (GA1, GA3, GA4, GA7, GA8, GA9, GA19, GA20, and GA53) were quantified by the use of deuterated GA internal standards. Paclobutrazol trunk drench treatments reduced vegetative shoot elongation in the seasons that seeds were sampled by 55% or more. Between June 17, 1987 and July 15, 1987, the dry weight of seeds from both untreated and treated trees increased about 2.5 times and there were reductions, on a per seed basis, of GA4 in seeds from both untreated and treated trees, of GA7 in seeds from treated trees, and of GA9 in seeds from untreated trees. However, GA9 increased in seeds from treated trees. Changes in levels of some of the early-13-hydroxylation pathway GAs (GA15 GA3, GA8, GA19, GA20, and GA53) also occurred during the month. For mid-July harvested seeds, the pattern, with some exceptions, was that 2 years after paclobutrazol treatment (1987), levels of early-13-hydroxylation pathway GAs in seeds from treated trees were lower compared to controls but after 5 years (1990) their levels tended to increase. For the non-13-hydroxylated GAs (GA4, GA7, and GA9), 2 years after paclobutrazol treatment, GA4 levels were equal in seeds from untreated and treated trees, GA7 decreased in seeds from treated trees compared with controls, but GA9 levels increased. Levels of these three GAs were higher in seeds from treated trees 5 years after treatment (1990) but levels of GA4, GA7, and GA9 dramatically increased in seeds from treated trees 4 years after treatment (1989), as we previously reported.  相似文献   

20.
Seed maturation of Pisum sativum cv. Progress No. 9 proceeds more slowly in winter than in summer even when the parent plants are grown in greenhouse conditions with light-and heat-supplementation. For parent plants grown under summer and winter conditions the metabolism of [3H]GA9 in cultured seeds is qualitatively different in seeds of equivalent age and qualitatively the same in seeds of equivalent weight. 13-Hydroxylation of [3H]GA9[3H]GA20 is restricted to early stages of seed development. 2-Hydroxylation of [3H]GA92-OH-[3H]GA9 has only been observed at a stage of development after endogenous GA9 has accumulated. 2-OH-GA9 has been shown to be endogenous to pea and is named GA51. H2-GA31 and its conjugate have not been shown to be present in pea and may be induced metabolites of [3H]GA9. The metabolism of GA20GA29 is used to illustrate a technique of feeding [2H][3H]GAs in order to distinguish a metabolite from the same endogenous compound. The in vitro conversion of [3H]GA20[3H]GA29, and the virtual non-metabolism of [3H]GA29 have been confirmed for seeds in intact fruits. These results are discussed in relation to the apparent absence of conjugated GAs in mature pea seeds.Abbreviations GAn gibberellin An - GC gas chromatography - GC-MS combined gas chromatography-mass spectrometry - GC-RC combined gas chromatography-radio counting - Me methyl ester - RT etention time - SICM selected ion current monitoring - TLC thin layer chromatography - TMS trimethyl silyl ether The author is née Frydman  相似文献   

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