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1.
Nakayama Ishizue; Kamiya Yuji; Kobayashi Masatomo; Abe Hiroshi; Sakurai Akira 《Plant & cell physiology》1990,31(8):1183-1190
Inhibition of the biosynthesis of gibberellins by prohexadione,3,5-dioxo-4-propionylcyclo-hexanecarboxylic acid, was studiedwith cell-free systems derived from immature seeds of Cucur-bitamaxima, Phaseolus vulgaris and Pisum sativum. Prohexadione,at a concentration of 104 M, inhibited C-7 oxidationof GA12-aldehyde, C-20 oxidation of GA15, conversion of C20-gib-berellinsto C19-gibberellins, 3ß-hydroxylation, 2,3-dehydrogenationof GA20, 2,3-epoxidation of GA5 and 2ß-hydroxylationof GA9 and GA20. The 3ß-hydroxylase activity appearedto be more sensitive to prohexadione than were the C-20 oxygenaseand the 2ß-hydroxylase activities. The conversionof mevalonic acid to GA12-aldehyde and the 13-hydroxylationof GA12 were not affected by prohexadione at a concentrationof 3 ? 104 M. All of the steps inhibited by prohexadioneare oxidation steps catalyzed by soluble enzymes that require2-oxoglutarate, Fe2+ and oxygen, and all of them occur distalto the synthesis of GA12-aldehyde in the biosynthesis of gibberellins. (Received April 4, 1990; Accepted September 14, 1990) 相似文献
2.
Functional Significance of Acid Phosphatase Distribution During Embryo Development in Pisum sativum L 总被引:4,自引:0,他引:4
The distribution of P1, ester P and acid-insoluble nucleic acidP has been studied in relation to acid phosphatase activity(EC 3. 1. 3. 2) in the component parts of developing pea seeds(Pisum sativum L.). Despite the favourable pH of the liquidcontents of the embryo sac (pH 5.5), only very low acid phosphataseactivity was detected in this fluid (c. 0.01 units per seed).Potential substrates for phosphatase action were in fact absentfrom the secretion, the only form of P present being Pi, inconcentrations up to 8 mM. The data support the hypothesis thatthe high acid phosphatase activities which develop in the seed-coatsare involved in regulating the supply of P as P1 to the developingembryo. Pisum sativum L., pea, embryo development, acid phosphatase, phosphorus, seed-coats, seed development 相似文献
3.
The role of gibberellic acid (GA3) in controlling the secretion(across the plasma membrane) and release (through the cell wall)of acid phosphatase (E.C. 3.1.3.2
[EC]
.) from Avena aleurone layershas been investigated. Evidence from this comparative studywith intact aleurone layers and isolated aleurone protoplastsreveals that the secretion of acid phosphatase is under GA3control. The mechanism underlying secretion and release of theenzyme from aleurone cells is discussed. Key words: Avena fatua, Acid phosphatase, Aleurone protoplasts, Gibberellic acid, Secretion 相似文献
4.
Kwak Sang-Soo; Kamiya Yuji; Takahashi Masahiro; Sakurai Akira; Takahashi Nobutaka 《Plant & cell physiology》1988,29(4):707-711
The metabolism of [14C]GA20 during seed maturation of Phaseolusvulgaris was studied using cell-free systems from embryos rangingin age from 10 DAF (day after flowering) to 24 DAF. Enzyme preparationsfrom very immature seeds actively converted GA20 to GA1, GA5and GA6. The ratio of incubation products suggested the biosyntheticpathway of GA20GA5GA6. Fluctuation in the levelsof endogenous C19-GAs, namely GA1, GA4, GA5, GA6, GA8, GA9 andGA20 was analyzed by GC-SIM using internal standards to compareenzyme activity with the levels of endogenous GAs. AlthoughGA1, GA4 and GA6 showed maximum levels on 20 DAF, enzyme activitydecreased during seed maturation and showed weak activity on20 DAF.
1Graduate student of the University of Tokyo, Department ofAgricultural Chemistry, Bunkyo-ku, Tokyo 113, Japan.
3Present address: Pesticides Research Laboratory, TakarazukaResearch Center, Sumitomo Chemical Co., Ltd., Takarazuka, Hyogo655, Japan. (Received December 17, 1987; Accepted March 30, 1988) 相似文献
5.
Gibberellins GA1, GA4, GA8, GA9, GA19, GA20, GA29, GA44, GA81,indole-3-acetic acid (IAA) and abscisic acid (ABA) were identifiedin cambial region tissues of Eucalyptus globulus by comparingmass spectra and Kovats retention indices with those of authenticstandards. Using stable isotope labelled internal standardsGA19, GA20 and GA44 were quantified at levels of 27 ng(g fr wt)-1, other GAs were present at levels < 1 ng (g frwt)-1. Levels of IAA and ABA ranged from 4171, 140 ng(g fr wt)-1 and 86305 ng (g fr wt)-1 respectively. Thepresence of brassinosteroid-like substances was also indicatedbased on activity in the rice seedling leaf inclination assay. (Received April 28, 1995; Accepted June 20, 1995) 相似文献
6.
Triticum durumCappelli has a relativedormancy which can be broken by dry after-ripening at room temperature.The breakage of dormancy in the embryos of T. durum , is accompaniedby a decline in content and a different degree of synthesisof poly(A)+RNA. This work studies the activity of poly(A) polymerase(E.C. 2.7.7.19), the enzyme which permits polyadenylation. Anincrease in the activity of this enzyme in parallel with theenhanced rate of germination is revealed. Since poly(A) polymeraseactivity is the same in dormant and non-dormant dry embryos,it seems that the activity of the enzyme is not involved inthe breakage of dormancy. The use of cycloheximide and cordycepinshows the presence of enzymes with different origins: a storedenzyme and one bound to a long lived mRNA, present in dormantand non-dormant embryos, plus an enzyme bound to newly synthesizedmRNA which is mainly active in non-dormant embryos. Since dormancycould be the result of an interaction between hormones, thiswork analyses the effects of GA3and ABA on poly(A) polymerase.GA3enhanced poly(A) polymerase activity only in dormant embryoswhile ABA inhibited this activity only in non-dormant embryos.Cycloheximide applied to excised wheat embryos represses thestimulatory and inhibitory effects of GA3and ABA, respectively.The hormone action on poly(A) polymerase activity is thus dependenton de novo protein synthesis. Results using cordycepin suggestthe presence of a stored mRNA for poly(A) polymerase, togetherwith hormonal regulation of enzyme activity at a translationallevel. Copyright 1999 Annals of Botany Company Triticum durum , wheat, dormancy breakage, poly(A) polymerase, GA3, ABA, germination. 相似文献
7.
Effects of Gibberellins on Seed Germination of Phytochrome-Deficient Mutants of Arabidopsis thaliana 总被引:7,自引:0,他引:7
Yang Young-Yell; Nagatani Akira; Zhao Yu-Ju; Kang Bong-Joong; Kendrick Richard E.; Kamiya Yuji 《Plant & cell physiology》1995,36(7):1205-1211
Experiments were carried out to explore the involvement of gibberellins(GAs) in the light-induced germination of Arabidopsis thaliana(L.) Heynh, using wild type (WT) and phytochrome-deficient mutants(phyA, phyB and phyAphyB deficient in phytochrome A, B and Aplus B, respectively). Seed germination of WT and phytochrome-deficientmutants was inhibited by uniconazole (an inhibitor of an earlystep in biosynthesis of GA, the oxidation of ent-kaurene) andprohexadione (an inhibitor of late steps, namely, 2rß-and 3rß-hydroxylation). This inhibition was overcomeby simultaneous application of 10-5 M GA4. The relative activityof GAs for promoting germination of uniconazole-treated seedswas GA4>GA1=GA9>GA20. The wild type and the phyA and phyBmutants had an increased response to a red light pulse in thepresence of GA1, GA4, GA9, GA20 and GA24 but there were no significantdifferences in activity of each GA between the mutants. Therefore,neither phytochrome A nor hytochrome B appears to regulate GAbiosynthesis from GA12 to GA4 during seed germination, sincethe conversion of GA12 to GA9 is regulated by one enzyme (GA20-oxidase). However, GA responsiveness appears to be regulatedby phytochromes other than phytochromes A and B, since the phyAphyBdouble mutant retains the photoreversible increased responseto GAs after a red light pulse. (Received February 13, 1995; Accepted July 11, 1995) 相似文献
8.
Jelsema Carole L.; Ruddat Manfred; Morr? D. James; Williamson Francis A. 《Plant & cell physiology》1977,18(5):1009-1019
A subcellular fraction enriched in aleurone grains isolatedin glycerol from aleurone layers of wheat endosperm specificallyand reversibly bound GA1-(3H). Specific binding of GA1 to otherfractions including spherosomes, nuclei, mitochondria, and plasmamembranes was negligible. The Kd of binding to aleurone grainswas 1.5 µM and the number of specific binding sites 0.45pmoles per mg protein. The presence of Ca++ ions was absolutelyrequired for binding. Abscisic acid which inhibits giberellinaction in vivo prevented specific GA1-binding in vitro. GA1-bindingto aleurone grains is important to the primary action of thehormone which may involve mobilization of reserves from thealeurone grain-spherosome complex for utilization in membranebiogenesis.
1 Present address: Section of Cytology, Yale University Schoolof Medicine, New Haven, CT 06510, U.S.A.
3 Present address: Laboratoire de Biologie V?g?tale, Ecole NormaleSup?rieure, 24 rue Lhomond, 75231 Paris, France. (Received March 28, 1977; ) 相似文献
9.
Tritiated GA1 and four of its synthetic derivatives were studiedin relation to their biological activity, uptake and metabolismby barley aleurone layers. Incubation was done in the presenceand absence of ABA. Tentative identification of some of themetabolites was made by TLC and GLC radiocounting of the metaboliteand its acid hydrolyzed derivative. Only GA1 promoted -amylase synthesis. Uptake ranged from 20to 42%, varying with the derivative. ABA enhanced uptake of[3H]GA1 and [3H]pseudoGA1 and inhibited uptake of [3H]ketoGA1the Wagner-Meerwein rearrangement product of [3H]GA1 Uptakeof [3H]GA1 methyl ester ([3H]GA1-Me) and [3H]dihydroGA1 wasunaffected by ABA. [3H]GA1 was converted to an amphoteric GA1 derivative ([3H]amphoGA1)and [3H]GA1-glycosyl ester. GA1-Me was metabolized to four products,all of them GA1 derivatives, including an apparent amphotericGA1 derivative. DihydroGA1 was quite stable; only one metabolitewas produced in sufficient yield to analyze. This product didnot cochromatograph with either of the expected acid hydrolyzedepimers of [3H]dihydroGA1. [3H]ketoGA1 was readily metabolizedto one product, probably the glycoside. [3H]pseudoGA1 remainedessentially unmetabolized. Metabolism of all compounds testedwas not dramatically affected by ABA. Surprisingly, no metabolitesfrom hydroxylation at the 2-position were found.
1 Present address: Monsanto Agricultural Co., 800 N. LindberghBlvd., St. Louis, MO 63166, U.S.A. (Received January 31, 1977; ) 相似文献
10.
Inoculation with Azospirillum lipoferum Affects Growth and Gibberellin Status of Corn Seedling Roots
Maize (Zea mays L., hybrid Cargill 147) seedlings, grown inaseptic conditions, were inoculated with three strains of Azospirillumlipoferum (Al op 33, Al iaa 320, and ATCC 29708) or culturedin different concentrations of indol-3-acetic acid (IAA) orgibberellin A3 (GA3). After 48 h, root length, root surfacearea, root dry weight, and shoot dry weight were measured inall treatments. Gibberellin content was evaluated in selectedroots of control and Azospirillum inoculated seedlings by gaschromatography-mass spectrometry-selected ion monitoring withthe use of deuterated gibberellins as internal standards. Thethree strains of A. lipoferum, IAA (2 ng ml1), and GA3(40 to 400 pg ml1) significantly enhanced root growth.Improvement of root hair growth and density was obtained mainlywith A. lipoferum strain Al op 33 and GA3 40 pg ml1.GA3 was identified by gas chromatography-mass spectrometry (byboth, full scan and selected ion monitoring) in a free acidfraction from roots of the seedlings inoculated with A. lipoferum.In the roots of the non inoculated seedlings GA3 was found afterhydrolysis of a fraction expected to contain glucosyl conjugates. (Received April 26, 1993; Accepted September 27, 1993) 相似文献
11.
ISHIZAKA NOBUYUKI; TOMIYAMA KOHEI; KATSUI NOBUKATSU; MURAI AKIO; MASAMUNE TADASHI 《Plant & cell physiology》1969,10(1):183-192
Rishitin, a norsesquiterpene alcohol, found in infected, resistantpotato-tuber tissue completely inhibited zoospore germinationand germtube elongation of Phytophthora infestans (MONT.) DEBARY at 103M. There was little difference in sensitivityto rishitin among races of Phytophthora infestans. IAA-inducedelongation of Avcna coleoptile sections and GA3-induced elongationof wheat leaf sections were also inhibited by rishitin. Theinhibition of IAA-induced elongation of Avena coleoptiles wasrelieved to some extent by increasing IAA concentration. However,little relief of the inhibition of GA3-induced elongation ofwheat leaf sections was obtained by increasing GA3 concentration.No plant injury was observed at this concentration of rishitin(103M). Examination of a series of rishitin derivatives indicated thatthe hydroxyl group at C-3 is indispensable for antifungal activity.This activity was intensified by saturating the double bondbetween the rings of rishitin and/or that of the isopropenylgroup at C-7, though activity decreased when oxygenated functionalgroups were introduced into the side chain. Aromatization of the A ring did not lower biological activities.The antifungal activities of most rishitin derivatives almostparalleled their activities as plant growth retardants. However,some compounds without antifungal activity were active as growthretardants.
1Studies on the phytoalexins (5). (Received August 14, 1968; ) 相似文献
12.
Gibberellic acid (GA3) at 58 µM, indoleacetic acid (IAA)at 29 µM, and (2-chloroethyl) phosphonic acid (Ethephon)at 70 µM promoted pollen tube growth in Crotalaria junceapollen suspension cultures both in water and basal medium. GA3stimulated [ l-14C]acetate incorporation into total lipids inboth media, whereas IAA enhanced incorporation in water culturesonly. On the contrary, Ethephon reduced the label in total lipidswhen supplemented in basal medium. Based on [l-14C lacetateincorporation into different phospho- and glycolipids, it isproposed that these growth regulators have a definite role inthe biosynthesis of lipid components of the membranes. 相似文献
13.
Removal of the blade from the leaf subtending the first flowerbud on Cyclamen persicum Swan Lake plants causedthe petiole of that leaf to senesce, but had no effect on thegrowth of the flower peduncle in the debladed petiole's axil.A 10 mg NAA l1 application generally had no effect onpetiole senescence, peduncle elongation or flowering date whenapplied to the cut end of the petiole after blade removal. A25 mg GA3 l1 application or a combination of 25 mg GA3l1 application or a combination of 25 mg GA3 l1plus 10 mg NAA l1 delayed petiole senescence and enhancedpeduncle elongation and subsequent flowering. No treatment significantlyaltered peduncle length at the time of flowering. Cyclamen persicum Mill, Swan Lake, tissue receptivity, flowering, GA3, NAA 相似文献
14.
Effects Produced on Tomato Plants, Lycopersicum esculentum, by Seed or Root Treatment with Gibberellic Acid and Indol-3yl-Acetic Acid 总被引:2,自引:0,他引:2
BROWN MARGARET E.; JACKSON R. M.; BURLINGHAM SUSAN K. 《Journal of experimental botany》1968,19(3):544-552
Growth in lengths of tomato stems and leaves was acceleratedby 5.0 µg gibberellic acid (GA2) applied to the seed,or by 5.0, 0.5, and 0.05 µg given to the roots. Treatmentwith 5.0 µg also decreased bud number and lengthened thetime between bud appearance and fruit formation on the firsttruss by 18 days. Smaller amounts applied to roots shortenedthis time by 14 days. Indol-3yl-acetic acid at 0.5 µghad no effect, nor was simultaneous application of GA3 and IAAto the roots more effective than GA3, alone. Single applicationsof very small amounts of GA3 to seeds or seedling roots thusproved capable of changing growth-rates of stems, leaves, andtrusses.The effects of treating tomatoes with GA2 and with culturesof Azotobacter chroococcum, which contain small amounts of GA3,and IAA, are compared. 相似文献
15.
Effect of Hormones on Sucrose Uptake and on ATPase Activity of Citrus sinensis L. Osbeck Leaves 总被引:1,自引:0,他引:1
Carbohydrate accumulation in young, fully expanded leaves ofCitrus sinensis L. Osbeck is affected by the presence of thefruitlet on the shoot. Previous work gave evidence that gibberellinsmay be involved in this 'fruit effect'. In the present workwe have studied the effect of gibberellic acid (GA3) on 14C-sucroseuptake by leaf discs and whether its action could be due toa modulation of the plasma membrane ATPase, which maintainsthe H+ gradient that drives H+/sucrose co-transport. The effect of GA3 on 14C-sucrose uptake depended on the osmolarityof the assay medium. At 300 mOsm a reduction in the uptake ratewas observed. The inhibitory effect of the hormone disappearedafter preincubating the leaf discs with para-chloromercuri-phenylsulphonicacid (PCMPS), a sulphydril binding inhibitor. ATPase activityof isolated plasma membrane vesicles was inhibited by IAA treatments,while GA3 or ABA did not affect this enzyme, even after a 3h preincubation period. However, in the absence of a surfactantin the assay medium, GA3, together with turgor pressure, modulatedplasma membrane ATPase activity, possibly through modificationsof membrane permeability. The hormone effect on 14 C-sucroseuptake may involve action on the sucrose carrier.Copyright 1994,1999 Academic Press Abscisic acid, Citrus sinensis, gibberellic acid, indoleacetic acid, orange, osmotic pressure, plasma membrane ATPase, 14C-sucrose uptake 相似文献
16.
Kwak Sang-Soo; Kamiya Yuji; Sakurai Akira; Takahashi Nobutaka; Graebe Jan E. 《Plant & cell physiology》1988,29(6):935-943
Gibberellin 3/ß-hydroxylase,a 2-oxoglutarate-dependentdioxygenase that catalyzes the hydroxylation of GA20 to GA1,was purified 313-fold from immature seeds of Phaseolus vulgarisL. The mol wt of the enzyme was estimated to be 42,000 by gelfiltration HPLC and SDS-polyacrylamide gel electrophoresis.The enzyme exhibited maximum activity at pH 7.7. The Km valuesfor [2,3-3H]GA20 and [2,3-3H]GA, were 0.29µu and 0.33µm, respectively. The enzyme requires 2-oxoglutarate asa cosubstrate; the Km value for 2-oxoglutarate was 250µMusing [3H]- GA20 as a substrate. Fe2+ and ascorbate significantlyactivated the enzyme at all purification steps, while catalaseand BSA activated the purified enzyme only. The enzyme was inhibitedby divalent cations Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+ and Hg2+.3ß-Hydroxylation of [3H]- GA20 was also inhibitedby non-radioactive GA5, GA9,GA15, GA20 and GA44. The possiblesite of 3ß-hydroxylation in gibberellin biosynthesisis discussed in terms of the substrate specificity of partiallypurified gibberellin 3ß-hydroxylase. (Received February 29, 1988; Accepted June 3, 1988) 相似文献
17.
Gibberellic acid (GA3) 20 mg 1?1 and (2-chloroethyl) phosphonic acid (Ethephon) 10 mg 1?1 enhanced pollen tube length in Crotalaria juncea L. GA3 markedly increased the activity of amylase, acid phosphatase and β-glucosidase and enhanced leaching of amylase and acid phosphatase enzymes. The rise in the activity level and leaching of amylase and acid phosphatase after Ethephon treatment was comparatively less than that of GA3 and the response to Ethephon was restricted to the 45 and 90 min period of culturing. Ethephon did not affect the activity/leaching of β-glucosidase significantly. Actinomycin-D (Act.D) 25 mg l?1 and Cycloheximide (CH) 10 mg 1?1 reduced the tube growth as well as activity of these enzymes suggesting their de novo synthesis during pollen tube growth. 相似文献
18.
The treatment of potato tubers with 150 µmol dm3gibberellic acid (GA3) stimulated starch breakdown and hexoseaccumulation in tuber tissues and the transfer of dry matterto stems. These effects could not be accounted for by enhancedactivities of starch phosphorylase, amylase and acid invertase.Indeed enzyme activities either declined or remained relativelyconstant as starch degradation and hexose accumulation proceeded.Changes in the rate of starch depletion were related to changesin sink strength and sink type, the onset of tuber initiationin controls causing the rate of starch degradation to exceedthat in GA3-treated tissues, in which tuberization was inhibited. Solanum tuberosum L., gibberellic acid, starch breakdown 相似文献
19.
In Pisum sativum L. a third, more severe, allele at the internodelength locus le is identified and named led. Plants homozygousfor led possess shorter internodes and appear relatively lessresponsive to GA20 than comparable le (dwarf) plants. Gene ledmay act by reducing the 3ß-hydroxylation of GA20 tothe highly active GA1 more effectively than does gene le. Theresults indicate that le is a leaky mutant and therefore thatendogenous GA1 influences internode elongation in dwarf (le)plants. Pisum sativum, peas, internode length, genetics, gibberellin, dwarf elongation 相似文献
20.
Song Nam Hi; Fujioka Shozo; Kamiya Yuji; Sakurai Akira; Liu Jang Ryol 《Plant & cell physiology》1991,32(6):783-789
The metabolism of GA12 and its precursors was investigated incultured cells of seven cell lines of Nicotiana tabacum andthree cell lines of Catharanthus roseus using l4C-labeled substrates.The presence of a metabolic pathway from ent-7-hydroxykaurenoicacid to GA53 via GA12-aldehyde and GA12 was demonstrated inthe cultured cells. GA12 was effectively converted to GA53 incells of BY-2, 2b-4, 2b-13 and CG from N. tabacum. By contrast,GA53 was not converted to any other GAs in all of the linesof cells examined. The metabolism of C19-GAs was also examinedusing 3H-labeled substrates. The conversion of GA20 to GA29and GA, and of GA4 to GA34 occurred more efficiently in cellsfrom C. roseus than in cells from N. tabacum. However, 13-hydroxylationof GA4 and GA9 was not observed in any of the cell culturesexamined. Among the various metabolites, GA53, GA29 and GA34were identified by full-scan GC/MS. (Received December 20, 1990; Accepted May 27, 1991) 相似文献