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1.
The levels of the biologically active gibberellin (GA), GA1, and of its precursor, GA20, were monitored at several stages during ontogeny in the apical portions of isogenic tall (Le) and dwarf (le) peas (Pisum sativum L.) using deuterated internal standards and gas chromatography-selected ion monitoring. The levels of both GAs were relatively low on emergence and on impending apical arrest. At these early and late stages of development the internodes were substantially shorter than at intermediate stages, but were capable of large responses to applied GA3. Tall plants generally contained 10–18 times more GA1 and possessed internodes 2–3 times longer than dwarf plants. Further, dwarf plants contained 3–5 times more GA20 than tall plants. No conclusive evidence for the presence of GA3 or GA5 could be obtained, even with the aid of [2H2]GA3 and [2H2]GA5 internal standards. If GA3 and GA5 were present in tall plants, their levels were less than 0.5% and 1.4% of the level of GA1, respectively. Comparison of the effects of gene le on GA1 levels and internode length with the effects of ontogeny on these variables shows that the ontogenetic variation in GA1 content was sufficient to account for much of the observed variation in internode length within the wild-type. However, evidence was also obtained for substantial differences in the potential length of different internodes even when saturating levels of exogenous GA3 were present.Abreviations GAn
gibberellin An
We thank Noel Davies, Omar Hasan, Leigh Johnson, Katherine McPherson and Naomi Lawrence for technical help, Professor L. Mander (Australian National University, Canberra) for deuterated GA standards and the Australian Research Council for financial assistance. 相似文献
2.
Valerie A. Smith 《Planta》1993,191(2):158-165
The physiological and biochemical consequences of treating Le (tall) and le (dwarf) pea seedlings with varying quantities of the gibberellins [3H]GA20 and GA1 have been investigated. Although the percentage uptake of these compounds from the site of application on the 3 stipules was low and most of the applied GA remained unmetabolised in situ, the quantitative relationship between GA translocation and GA dosage was found to be linear for GA1 but saturating for GA20. The movement of the GAs and their subsequently produced metabolites was mainly acropetal. They accumulated in greatest quantity in the apical extremities of the shoot. Overall, the extent to which GA20 was metabolished in le seedlings was considerably less than in Le pea seedlings. Although all le tissues contained significantly less [3H]GA1 than their Le counterparts, phenotypic effects of the le mutation were apparent only on internode and tendril development. Increased tissue growth, consequent upon GA treatment, was also apparent only in the internodes and tendrils of le plants. For internodes, GA1 content determined the mid-logarithmic-phase growth rate and, consequently, final length. For tendrils, GA20 rather than GA1 may be the primary stimulatory agent.Abbreviations GA
gibberellin
- HPLC
high-performance liquid chromatography
- 1–6
consecutive developmental numbering system for plant tissues/organs as shown in Fig. 1
The author gratefully acknowledges financial support from Imperial Chemical Industries, Plant Protection, Jealott's Hill, Bracknell, Berks., UK and the Science and Engineering Research Council. 相似文献
3.
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
4.
The metabolism and growth-promoting activity of gibberellin A20 (GA20) were compared in the internode-length genotypes of pea, na le and na Le. Gibberellin A29 and GA29-catabolite were the major metabolites of GA20 in the genotype na le. However, low levels of GA1, GA8 and GA8-catabolite were also identified as metabolites in this genotype, confirming that the le allele is a leaky mutation. Gibberellin A20 was approximately 20 to 30 times as active in promoting internode growth of genotype na Le as of genotype na le. However, the levels of the 3-hydroxylated metabolite of GA20, GA8 (2-hydroxy GA1), were similar for a given growth response in both genotypes. In each case a close linear relationship was observed between internode growth and the logarithm of GA8 levels. A similar relationship was found on comparing GA20 metabolism in the three genotypes le
d, le and Le. The former mutation results in a more severe dwarf phenotype than the le allele (which has previously been shown to reduce the 3-hydroxylation of GA20 to GA1). These results indicate that GA20 has negligible intrinsic activity and support the contention that GA1 is the only GA active per se in promoting stem growth in pea.Abbreviations GAn
gibberellin An
- GC-MS
gas chromatography-mass spectrometry
- HPLC
high-pressure liquid chromatography 相似文献
5.
6.
Identification,quantitation and distribution of gibberellins in fruits of Pisum sativum L. cv. Alaska during pod development 总被引:1,自引:0,他引:1
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
7.
The evolution of the total amount of DNA in epicotyls and of the amount of DNA per cell nucleus in epicotyl cortex cells during germination was followed in two closely related pea varieties, Pisum sativum cv. Finale and Pisum sativum cv. Rondo. Under etiolating conditions, growth of the cv. Rondo occurs only by cell elongation which is preceded by endomitotic DNA synthesis, while in the cv. Finale growth is the result of cell elongation accompanied by endomitotic DNA synthesis and cell division. The maximum C-level attained in both cultivars under etiolating conditions is 8 C (C=haploid amount of DNA in a gamete cell). Both the maximum C-level reached and the percentage of cells reaching this C-level seem to be under strict genetic control. In both cultivars, light inhibits the endomitotic DNA replication.Neither gibberellic acid (GA3), nor AMO 1618 alter the maximum C-level or the percentage distribution of the C-classes. Both growth regulators are effective, although in an opposite way, only in tissues where cell division occurs or where endomitotic DNA synthesis is blocked, as in light-grown pea epicotyls. 相似文献
8.
5-Enolpyruvylshikimate 3-phosphate synthase (3-phosphoshikimate 1-carboxyvinyltransferase; EC 2.5.1.19) from shoot tissue of pea seedlings was purified to apparent homogeneity by sequential ammonium-sulphate precipitation, ion-exchange and hydrophobic-interaction chromatography and substrate elution from cellulose phosphate. Gel electrophoresis and gel-permeation chromatography showed that the purified enzyme was monomeric with molecular weight 50,000. The herbicide glyphosate was a potent inhibitor of the forward enzyme-catalyzed reaction.Abbreviations DEAE
diethylaminoethyl
- EPSP
5-enolpyruvylshikimate 3-phosphate 相似文献
9.
V. M. Sponsel 《Planta》1986,168(1):119-129
The stem growth in darkness or in continuous red light of two pea cultivars, Alaska (Le Le, tall) and Progress No. 9 (le le, dwarf), was measured for 13 d. The lengths of the first three internodes in dark-grown seedlings of the two cultivars were similar, substantiating previous literature reports that Progress No. 9 has a tall phenotype in the dark. The biological activity of gibberellin A20 (GA20), which is normally inactive in le le geno-types, was compared in darkness and in red light. Alaska seedlings, regardless of growing conditions, responded to GA20. Dark-grown seedlings of Progress No. 9 also responded to GA20, although red-light-grown seedlings did not. Gibberellin A1 was active in both cultivars, in both darkness and red light. The metabolism of [13C3H]GA20 has also been studied. In dark-grown shoots of Alaska and Progress No. 9 [13C3H]GA20 is converted to [13C3H]GA1, [13C3H]GA8, [13C]GA29, its 2-epimer, and [13C3H]GA29-catabolite. [13C3H] Gibberellin A1 was a minor product which appeared to be rapidly turned over, so that in some feeds only its metabolite, [13C3H]GA8, was detected. However results do indicate that the tall growth habit of Progress No. 9 in the dark, and its ability to respond to GA20 in the dark may be related to its capacity to 3-hydroxylate GA20 to give GA1. In red light the overall metabolism of [13C3H]GA20 was reduced in both cultivars. There is some evidence that 3-hydroxylation of [13C3H]GA20 can occur in red light-grown Alaska seedlings, but no 3-hydroxylated metabolites of [13C3H]GA20 were observed in red light-grown Progress. Thus the dwarf habit of Progress No. 9 in red light and its inability to respond to GA20 may be related, as in other dwarf genotypes, to its inability to 3-hydroxylate GA20 to GA1. However identification and quantification of native GAs in both cultivars showed that red-light-grown Progress does contain native GA1. Thus the inability of red light-grown Progress No. 9 seedlings to respond to, and to 3-hydroxylate, applied GA20 may be due to an effect of red light on uptake and compartmentation of GAs.Abbreviations AMO-1618
2-isopropyl-4-(trimethylammonium chloride)-5-methylphenyl piperidine-1-carboxylate
- cv.
cultivar
- GC-MS
gas chromatography-mass spectrometry
- GA(n)
gibberellin A(n)
- HPLC
high-pressure liquid chromatography 相似文献
10.
The metabolism of GA29 in maturing seeds of Pisum sativum cv. Progress No. 9 was further investigated, and the utility of 2H-labelled GAs in conjuction with GC-MS is illustrated. Using [2-2H1]GA29 as an internal standard, endogenous GA29 was shown to reach a maximal level (ca. 10 g/seed) 27 days from anthesis, and to decline to ca. 1.6 g/seed in mature seeds. In a time-course feed the metabolism of [2-2H1] [2-3H1]GA29 applied to 27 day old seeds, and of endogenous GA29, was compared from the 1H:2H ratios in the recovered GA29. Although both [2-2H1] [2-3H1]GA29 and endogenous GA29 were metabolised to the same limited extent to a putative conjugate, in the main metabolic process endogenous GA29 was preferentially converted to an untraceable (i.e. unlabelled) metabolite. In contrast, endogenous GA29 and [1,3-2H2] [1,3-3H2]GA29, derived from [1,3-2H2] [1,3-3H2]GA20 in a time-course feed, were metabolised in an identical manner. In the latter case isotope loss precluded identification of the metabolite. The structure (8) has been assigned to a GA catabolite present in maturing seeds and seedlings of pea. The isotope data are consistent with this compound being the hitherto untraced metabolite of GA29 in pea.Abbreviations GAn
gibberellin An
- GC
gas chromatography
- GC-MS
combined gas chromatography-mass spectrometry
- GC-RC
combined gas chromatography-radio counting
- M+
molecular ion
- Me
methyl ester
- RT
retention time
- SICM
selected ion current monitoring
- TLC
thin layer chromatography
- TMS
trimethylsilyl ether 相似文献
11.
5-Enolpyruvylshikimate 3-phosphate (EPSP) synthase (3-phosphoshikimate 1-carboxyvinyltransferase; EC 2.5.1.19), 3-dehydroquinate dehydratase (EC 4.2.1.10) and shikimate: NADP+ oxidoreductase (EC 1.1.1.25) were present in intact chloroplasts and root plastids isolated from pea seedling extracts by sucrose and modified-silica density gradient centrifugation. In young (approx. 10-d-old) seedling shoots the enzymes were predominantly chloroplastic; high-performance anion-exchange chromatography resolved minor isoenzymic activities not observed in density-gradientpurified chloroplasts. The initial enzyme of the shikimate pathway, 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase (EC 4.1.2.15) was also associated with intact density-gradient-purified chloroplasts. 3-Dehydroquinate synthase (EC 4.6.1.3) and shikimate kinase (EC 2.7.1.71) were detected together with the other pathway enzymes in stromal preparations from washed chloroplasts. Plastidic EPSP synthase was inhibited by micromolar concentrations of the herbicide glyphosate.Abbreviations DAHP
3-deoxy-d-arabino-heptulosonate 7-phosphate
- DEAE
diethylaminoethyl
- DHQase
3-dehydroquinate dehydratase
- DTT
dithiothreitol
- EPSP
5-enolpyruvylshikimate 3-phosphate
- SORase
shikimate:NADP+ oxidoreductase 相似文献
12.
The relationship between shoot growth and [3H]gibberellin A20 (GA20) metabolism was investigated in the GA-deficient genotype of peas, na Le. [17-13C, 3H2]gibberellin A20 was applied to the shoot apex and its metabolic fate examined by gas chromatographic-mass spectrometric analysis of extracts of the shoot and root tissues. As reported before, [13C, 3H2]GA1, [13C, 3H2]GA8 and [13C, 3H2]GA29 constituted the major metabolites of [13C, 3H2]GA20 present in the shoot. None of these GAs showed any dilution by endogenous 12C-material. [13C, 3H2]GA29-catabolite was also a prominent metabolite in the shoot tissue but showed pronounced isotope dilution probably due to carry-over of endogenous [12C]GA29-catabolite from the mature seed. In marked contrast to the shoot tissue, the two major metabolites present in the roots were identified as [13C, 3H2]GA8-catabolite and [13C, 3H2]GA29-catabolite. Both of these compounds showed strong dilution by endogenous 12C-material. Only low levels of [13C, 3H2]GA1, [13C, 3H2]GA8, [13C, 3H2]GA20 and [13C, 3H2]GA29 accumulated in the roots. It is suggested that compartmentation of GA-catabolism may occur in the root tissue in an analogous manner to that shown in the testa of developing seeds. Changes in the levels of [1,3-3H2]GA20 metabolites over 10 d following application of the substrate to the shoot apex of genotype na Le confirmed the accumulation of [3H]GA-catabolites in the root tissues. No evidence was obtained for catabolic loss of [3H]GA20 by complete oxidation or conversion to a methanol-inextractable form. The results indicate that the root system may play an important role in the regulation of biologically active GA levels in the developing shoot of Na genotypes of peas.Abbreviations GAn
gibberellin An
- GC-MS
gas chromatography-mass spectrometry
- HPLC
high-pressure liquid chromatography 相似文献
13.
1. The uptake of indol-3-yl acetic acid ([1-14C]IAA, 0–2.0 M) into light-grown pea stem segments was measured under various conditions to investigate the extent to which mechanisms of auxin transport in crown gall suspension culture cells (Rubery and Sheldrake, Planta 118, 101–121, 1974) are also found in a tissue capable of polar auxin transport. — 2. IAA uptake increased as the external pH was lowered. IAA uptake was less than that of benzoic acid (BA), naphthylacetic acid (NAA) or 2,4 dichlorophenoxyacetic acid (2,4D) under equivalent conditions. TIBA enhanced net IAA uptake through inhibition of efflux, and to a lesser extent, also increased uptake of NAA and 2,4D while it had no effect on BA uptake. — 3. Both DNP and, at higher concentrations, BA, reduced IAA uptake probably because of a reduction of cytoplasmic pH. However, low concentrations of both BA and DNP caused a slight enhancement of IAA net uptake, possibly through a reduction of carrier-mediated IAA efflux. In the presence of TIBA, the inhibitory effects of DNP and BA were more severe and there was no enhancement of uptake at low concentrations. — 4. Non-radioactive IAA (10 M) reduced uptake of labelled IAA but further increases in concentration up to 1.0 mM produced first an inhibition (0–10 min) of labelled IAA uptake, followed by a stimulation at later times. Non-radioactive 2,4 D decreased, but was not observed to stimulate, uptake of labelled IAA. In the presence of TIBA labelled IAA uptake was inhibited by non-radioactive IAA regardless of its concentration. — 5. Sulphydryl reagents PCMB and PCMBS promoted or inhibited IAA uptake depending, respectively, on whether they penetrated or were excluded from the cells. The penetrant PCMB also reduced the promotion of labelled IAA uptake by TIBA or by high concentrations of added non-labelled IAA. — 6. Our findings are interpreted as being consistent with the diffusive entry of unionised IAA into cells together with some carrier-mediated uptake. Auxin efflux from the cells also appears to have a carrier-mediated contribution, at least part of which is inhibited by TIBA, and which has a capacity at least as great as that of the uptake carrier. The data indicate that pea stem segments contain cells whose mechanisms of trans-membrane auxin transport fit the model of polar auxin transport proposed from experiments with crown gall suspension cells, although differences, particularly of carrier specificity, are apparent between the two systems.Abbreviations IAA
indol-3-yl acetic acid
- BA
benzoic acid
- NAA
1-naphthylacetic acid
- 2,4-D
2,4-dichlorophenoxyacetic acid
- TIBA
2,3,5-triiodobenzoic acid
- DNP
2,4-dinitrophenol
- PCMB
p-chloromercuribenzoic acid
- PCMBS
p-chloromercuribenzene sulphonic acid
This work was performed in Cambridge during the tenure of a sabbatical leave by P.J.D. Supported by a grant for supplies from the American Philosophical Society to P.J.D. 相似文献
14.
The proportion of spurs flowering on apple trees (Malus domestica Borkh. cv Golden Delicious) displaying a high degree of alternate-year flowering was increased in the off year by gibberellin A4 (GA4) and C-3 epi-GA4 applied in the previous year. When applied 4.5 weeks after anthesis amounts of GA4 ranging from 3 to 300 g per spur and 25 or 50 g of C-3 epi-GA4 per spur were effective. Treatments with GA4 made seven weeks after anthesis were less effective. A combination of 30 g GA4 and 30 g zeatin (6-(4-hydroxy-3-methylbut-trans-2-enylamino)purine) promoted flowering at both treatment times, and tended to be more effective than GA4 alone.Abbreviation GA
gibberellin or gibberellin-like substance
Contribution No. 618 相似文献
15.
Carnitine-acetyltransferase (EC 2.3.1.7) and carnitine-palmitoyltransferase (EC 2.3.1.21) activities were shown to be present in chloroplasts of green pea leaves and possibly to occur in leaf mitochondrial and peroxisomal fractions. A role for the enzymes in the transfer of acyl groups across membranes is suggested. 相似文献
16.
Mutational analysis of Pisum sativum L. was used to search for constitutive proteins that might function in nodule formation. The sym 5 locus is a mutational hot spot, represented by seven independently derived mutant lines with decreased nodulation. Comparison of two-dimensional polyacrylamide gels of in vitro-translated root RNA showed a consistent difference in the migrational pattern of one peptide. In the nodulating parental cultivar Sparkle, a 66 kDa peptide had a pI of 5.9. In four of the five tested sym 5 mutants, the 66 kDa peptide had a more acidic pI of 5.8. This 66 kDa peptide is found in lateral root, tap root, and shoot. Its expression was independent of rhizobial inoculation, root temperature, or light. 相似文献
17.
In an early-flowering line of pea (G2) apical senescence occurs only in long days (LD), while growth in short days (SD) is indeterminate. In SD, G2 plants are known to produce a graft-transmissible substance which delays apical senescence in related lines that are photoperiod-insensitive with regard to apical senescence. Gibberellic acid (GA3) applied to the apical bud of G2 plants in LD delayed apical senescence indefinitely, while N6-benzyladenine and -naphthaleneacetic acid were ineffective. Of the gibberellins native to pea, GA9 had no effect whereas GA20 had a moderate senescence-delaying effect. [3H]GA9 metabolism in intact leaves of G2 plants was inhibited by LD and was restored by placing the plants back in SD. Leaves of photoperiod-insensitive lines (I-types) metabolized GA9 readily regardless of photoperiod, but the metabolites differed qualitatively from those in G2 leaves. A polar GA9 metabolite, GAE, was found only in G2 plants in SD. The level of GA-like substances in methanol extracts from G2 plants dropped about 10-fold after the plants were moved from SD to LD; it was restored by transferring the plants back to SD. A polar zone of these GA-like materials co-chromatographed with GAE. It is suggested that a polar gibberellin is synthesized by G2 plants in SD; this gibberellin promotes shoot growth and meristematic activity in the shoot apex, preventing senescence.Abbreviations GA
gibberellin
- GA3
gibberellic acid
- SD
short days
- LD
long days 相似文献
18.
The metabolism of GA29 during seed maturation in Pisum sativum cv. Progress No. 9 was further investigated. [17-13C1]GA29 was metabolised to a GA-catabolite (structure 3), with incorporation of the [13C] label from the GA29 substrate into the GA-catabolite being demonstrated by GC-MS. Quantitation of the GA-catabolite using GC-MS was achieved by adding GA-catabolite, labelled with [18O], to seed extracts as an internal standard. At least 50% conversion of [13C1]GA29 to [13C1]GA-catabolite was demonstrated with the build up of exogenous [13C1]GA-catabolite strictly paralleling the accumulation of native GA-catabolite. These results strongly suggest that conversion of GA29 to the GA-catabolite is a natural metabolic step occurring during the final stages of seed maturation. 25 g per seed of native GA-catabolite was recorded in 37 day old seeds. Some problems encountered in the analysis of extracts containing the GA-catabolite are discussed briefly.Abbreviations BSTFA
bis(trifluoromethylsilyl)acetamide
- GAn
gibberellin An
- GC
gas chromatography
- GC-MS
combined gas chromatography-mass spectrometry
- Me
methyl ester
- SICM
selected ion current monitoring
- TMSi
trimethylsilyl ether 相似文献
19.
Quantitative estimates of gibberellin A9 in Norway spruce extracts obtained by gas chromatography-mass spectrometry, radioimmunoassay (RIA_ and bioassay were compared after successive purifications of the extracts. The extracts were assayed in several dilutions with and without the addition of standard gibberellin A9, thus showing the effect of extract components on the response of the assays. Radioimmunoassay produced estimates comparable to gas chromatography-mass spectrometry after one purification step by high-performance liquid chromatography. Extracts purified by polyvinylpyrrolidone-column chromatography and solvent partitioning but not high-performance liquid chromatography resulted in inaccurate RIA estimates. The performance of the RIA could be monitored by logit-log transformations of the standard curve and extract dilution curve and by calculating the slope of the standard addition curve. It was, however, not possible to correct for the interference caused by extract components by the standard addition procedure. Quantifications by Tan-ginbozu dwarf-rice bioassay were accurate, but a large and unpredictable variation makes it unsuitable for quantitative determinations.Abbreviations FW
fresh weight
- GA9
gibberellin A9
- GA9–Me
methylated GA9
- GC-MS
gas chromatography-mass spectrometry
- HPLC
high performance liquid chromatography
- MID
multiple-ion detection
- RIA
radioimmunoassay 相似文献
20.
The effects of peeling and wounding on the indole-3-acetic acid (IAA) and fusicoccin (FC) growth response of etiolated Pisum sativum L. cv. Alaska stem tissue were examined. Over a 5 h growth period, peeling was found to virtually eliminate the IAA response, but about 30% of the FC response remained. In contrast, unpeeled segments wounded with six vertical slits exhibited significant responses to both IAA and FC, indicating that peeling does not act by damaging the tissue. Microscopy showed that the epidermis was removed intact and that the underlying tissue was essentially undamaged. Neither the addition of 2% sucrose to the incubation medium nor the use of a range of IAA concentrations down to 10-8 M restored IAA-induced growth in peeled segments, suggesting that lack of osmotic solutes and supra-optimal uptake of IAA were not important factors over this time period. It is concluded that, although the possibility remains that peeling merely allows leakage of hydrogen ions into the medium, it seems more likely that peeling off the epidermis removes the auxin responsive tissue.Abbreviations IAA
indole-3-acetic acid
- FC
fusicoccin 相似文献