共查询到20条相似文献,搜索用时 15 毫秒
1.
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
2.
We investigated the metabolism and translocation of two gibberellins(GAs), [3H]GA20 and [3H]GA1, which were applied at low concentrationto the cotyledons of Pharbitis nil (cv. Violet). Seedlings weregrown under three different photoperiodic conditions: continuouslight (CL-CL), continous light followed by short day conditions(CL-DT) and long day conditions followed by short day conditions(DT-DT). Translocation of the applied [3H]GAs from cotyledonsto hypocotyls was promoted by DT for all GAs examined. Whilethe conversion of the translocated [3H]GA1 to [3H]GA8 and itsconjugates was rapid in hypocotyl, the conversion of translocated[3H]GA20 to [3H]GA29 was slow. Radioactivity in epicotyls wasdetected much more rapidly on application of [3H]GA20 than of[3H]GA1, [3H]GA8 and [3H]GA29 and their conjugates. The conversionof [3H]GA20 to [3H]GA1 in the epicotyl was more rapid underCL-CL conditions. This result in consistent with the higherlevel of endogenous GA1 existing in epicotyls under CL-DT thanDT-DT conditions. However, when [3H]GA1 was applied to the cotyledon,only small amounts of [3H]GA8 and its conjugates were detectedin the epicotyl regardless of the photoperiodic conditions.This result may suggest that the translocation and metabolismof [3H]GA20 from cotyledons to epicotyl was faster under CL-CLthan DT-DT conditions and may correlate with the increased epicotylelongation of GA20 treated plants under CL-DT than DT-DT conditions. (Received June 28, 1995; Accepted November 2, 1995) 相似文献
3.
Yang Young-Yell; Yamaguchi Isomaro; Takeno-Wada Kiyotoshi; Suzuki Yoshihito; Murofushi Noboru 《Plant & cell physiology》1995,36(2):221-227
Gibberellin A1, (GA1), GA19, and GA20 in phloem exudates andcotyledons of seedlings of Pharbitis nil cv. Violet, grown underdifferent photoperiodic conditions, were qualitatively and semi-quantitativelyanalyzed by a combination of high performance-liquid chromatography(HPLC) and radioimmunoassays (RIA). The levels of GA19 and GA20were higher in cotyledons from plants grown under dark treatment(DT) conditons of 16 h-light/8 h-dark for 6 days followed by8 h-light/16 h-dark for 3 days than in those grown under continuouslight (CL) for 9 days. This relationship was also observed forthe GAs in phloem exudates, although the levels were much lowerthan in the cotyledons. When GAs were applied to the cotyledons,elongation of the epicotyl was promoted more by GA20 than byGA1 or GA19, especially under the CL treatment. The relativeeffect of GA1 and GA20 on the epicotyl elongation was reversedwhen these GAs were applied to epicotyls pre-treated with prohexadione,an inhibitor of 2-oxoglutarate-dependent dioxygenases.
3Present address: Frontier Research Program, The Institute ofPhysical and Chemical Research (RIKEN), 2-1 Hirosawa, Wakoshi,Saitama, 351-01 Japan
4Present address: Laboratory of Horticulture, Faculty of Agriculture,Nagoya University, Nagoya, 464-01 Japan 相似文献
4.
Phospholipid synthesis in wheat aleurone tissue was found tobe induced by imbibition. Radiotracer experiments using [Me-14C]cholineprecursor showed that the synthesized phospholipid was locatedin the microsomal fraction of the tissue. The most active periodof phospholipid synthesis was during the first day of germinationbefore gibberellic acid (GA3) responses were evident. GA3 was,in fact, without effect upon the rate of phospholipid synthesis,but evidence is presented which indicates that the hormone increasedthe rate of phospholipid breakdown. Abscisic acid (ABA) alsoinduced phospholipid breakdown, and ABA did not inhibit theGA3-induced breakdown. The relationship of phospholipid synthesisand membrane formation to the induction of hydrolase productionby GA3 is discussed. 相似文献
5.
Gibberellic acid and kinetin partially reverse the effect of water stress on germination and seedling growth in chickpea 总被引:3,自引:0,他引:3
The percent germination and seedling growth of chickpea (Cicer arietinum L. cv. PBG-1) decreased with increasing concentrations of exogenous polyethylene glycol 6000 (PEG). With 15% PEG in the growth medium germination was only 33% while with 10% PEG it was 58% as compared to 93% in control. Addition of gibberellic acid (GA3) and kinetin to medium containing 10% PEG increased the germination and seedling growth and the effect was maximum with 6 µM GA3 which was a better inducer of growth and germination under reduced water potential than kinetin. However, indole acetic acid (IAA) inhibited germination and growth of stressed seedlings. The activity of amylase in cotyledons under stress was significantly increased with GA3 while kinetin and IAA were less effective. Gibberellic acid also enhanced the mobilization of starch from cotyledons of stressed seedlings resulting in low starch levels in cotyledons compared with stressed seedlings. 相似文献
6.
By using light-grown cucumber (cv. Aonagajibae) seedlings withfully expanded cotyledons, the osmotic potential of the epidermalcells of the hypocotyl, as determined by the plasmolysis methodwas examined in relation to the effects of gibberellin (GA7)and cotyledons. GA7 at a dosage level of 0.05 µg/plantapplied to the apical bud lowered the osmotic potential; thedecrease was significant 5 hr after the GA7 treatment. Removalof the cotyledons, covering them with aluminum foil, or applyinglinuron, a DCMU analogue, to them caused an increase in thepotential. In light-grown cucumber seedlings, the maintenanceof a lower osmotic potential in the epidermal cells of the hypocotylwas concluded to be regulated by the photosynthetic activityof the cotyledon and also by gibberellin.
1Noriko Katsu, Kitano-Haitsu 203, Saginuma 1-9-10, Takatsu-ku,Kawasaki 218, Japan. (Received May 30, 1980; ) 相似文献
7.
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
8.
Effects of gibberellic Acid and gold light on germination, enzyme activities, and amino Acid pool size in a dwarf strain of watermelon 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Plant physiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Gibberellic acid (GA3) promotes and continuous gold light inhibits germination of seeds of a dwarf strain (WB-2) of watermelon [Citrullus lanatus (Thunb.) Matsu. and Nakai]. Osmotic inhibition of germination with mannitol in light-grown seeds of WB-2 was only slightly reversed by GA3 at the concentrations used, whereas, GA3 substantially relieved osmotic inhibition in dark-grown seeds.
The effects of GA3 and gold light on development of catalase and invertase activities and on levels of free amino acids in germinating seeds of WB-2 were examined. Light depressed development of catalase and invertase activity. Levels of free amino acids increased more slowly in embryonic axes of light- than dark-incubated seeds, but in cotyledons higher levels of amino acids were maintained in light-grown seeds. GA3 accelerated the development of catalase activity in whole embryos and invertase activity in embryonic axes, but did not significantly affect invertase activity in cotyledons during germination. GA3 had little effect on amino acid pools in cotyledons and embryonic axes.
相似文献9.
The present work deals with the effect of IAA-kinetin, IAA-GA3and GA3-ABA interactions on growth and gametangial formationin Riccia gangetica in vitro. Inhibitory effect of high concentrationof IAA on vegetative growth is overcome by the co-addition ofkinetin. The best response in terms of fresh and dry weightyields of thalli is obtained by a combination of 105mol dm3 kinetin+ 107 mol dm3 IAA. Interactionof IAA and kinetin has an additive effect on archegonial formation.Co-addition of IAA and GA3 decreases production of archegoniaand antheridia as compared to those produced in response toIAA and GA3 alone, respectively. Combination of GA3 and ABAreduces vegetative growth, as well as the number of anthendiaand archegonia. Key words: Riccia gangetica, growth, growth regulators, gametangial formation 相似文献
10.
The interaction of kinetin with IAA and GA3 on the elongationof hypocotyl sections of Cucumis sativus L. cv. National Picklingwas studied. Kinetin in the concentration range of 107M to 104 M markedly inhibited IAA-induced elongation,while in a lower range from 1010 M to 108 M, itsynergistically enhanced IAA-induced elongation. Kinetin alonein this range had no effect. A 5-to 15-min pulse treatment seemsenough to induce the maximum effect for both inhibition andpromotion. Since the magnitude of the maximum inhibition dependedon the concentration and not on the duration of treatment, thereaction in the cell caused by kinetin seemed to be completedwithin a short period. Washing of the sections with distilledwater after kinetin treatment (30 min) did not significantlyeliminate the kinetin effect. This probably indicates that thebinding of kinetin molecules to a supposed acceptor is not reversible.Interaction of kinetin with GA3 in their pretreatment effectson IAA-induced elongation shows that in the inhibitory concentrationrange, the kinetin effect was partly overcome by GA3, and thatin the promotive range, the magnitude of the enhancement wasdetermined by kinetin regardless of the presence of GA3. Theeffect of kinetin seems to dominate over that of GA3 indicatingthat the modes of their pretreatment effects differ from oneanother. (Received June 24, 1977; ) 相似文献
11.
E. Wilmowicz K. Frankowski P. Glazińska J. K?sy W. Wojciechowski J. Kopcewicz 《Biologia Plantarum》2011,55(4):757-760
Application of gibberellic acid (GA3) on the cotyledons of 5-d-old Pharbitis nil reversed the inhibitory effect of both abscisic acid (ABA) and ethylene on flowering. Application of GA3 slightly decreased ethylene production and did not affect the endogenous ABA content in the cotyledons during the night.
However, it reversed the stimulating effect of ABA on ethylene production. 相似文献
12.
Effect of Gibberellin on Growth, Protein Secretion, and Starch Accumulation in Maize Endosperm Suspension Cells 总被引:3,自引:0,他引:3
The physiologic effect of gibberellins (GA) in seed development is poorly understood. We examined the effect of gibberellic
acid (GA3) on growth, protein secretion, and starch accumulation in cultured maize (Zea mays L.) endosperm suspension cells. GA3 (5 and 30 μm) increased the fresh weight, dry weight, and protein content of the cultured cells, but the effect of GA3 at 50 μm was not significantly different. However, the protein content in the culture medium was increased by these three concentrations
of GA3. The effect of GA3 on the amount of cellular structural polysaccharides was not significant, but GA3 had a dramatic effect on the starch content. At 5 μm, GA3 caused an increase in the starch content, but at 50 μm the starch accumulation was reduced. Chlorocholine chloride (CCC), an inhibitor of GA biosynthesis, significantly increased
the starch content and decreased the structural polysaccharide content of the cultured cells. The effects of CCC at 500 μm on the starch and polysaccharide content were partially reversed by 5 μm GA3 applied exogenously. Based on these results we suggest that GA does not favor starch accumulation in the cell cultures and
that the addition of lower concentrations of GA3 in the medium may provide an improved balance among the endogenous GA in the cultured cells.
Received October 31, 1995; accepted March 25, 1997 相似文献
13.
Following stratification seeds of Corylus avellana exhibitedtheir characteristic ability to germinate at 20 °C undermoist conditions. Stratification of the intact fruit also stimulatedelongation of the cotyledonary petiole when isolated cotyledonswere transferred to moist conditions at 20 °C. GA3 inducedboth of these effects in non-stratified material. ABA substantiallydecreased seed germination and the response of cotyledonarypetioles to stratification and GA3. CCC2 applied to stratifiedor GA3-pretreated cotyledons did not depress the final percentageof growing petioles. Cotyledons can clearly regulate the development of their petiolesin the absence of the embryonic axis. It is concluded that thereis at least one gibberellin-sensitive site in the cotyledonscapable of initiating petiole development independent of axiscontrol. 相似文献
14.
《Plant & cell physiology》1980,21(8):1343-1346
The effects of abscisic acid (ABA) and gibberellic acid (GA3)on the chemical composition of and tuberization in the potatowere studied. GA3 at 106 M inhibited and ABA at an equimolarconcentration promoted tuberization. The inhibitory effect ofGA3 was relieved by the addition of ABA. The fresh weight ofthe shoot, chlorophyll content and the total glycoalkaloidslevel were increased by GA3 treatment, but decreased by ABAtreatment. In contrast, total proteins were increased by ABA,but decreased by GA3 treatment.
1This work was supported by a PL-480 research grant (FG-Pa-262)from the United States Department of Agriculture widi co-ordinationby the Agriculture Research Council, Pakistan. (Received August 29, 1980; ) 相似文献
15.
《Plant & cell physiology》1980,21(7):1343-1346
The effects of abscisic acid (ABA) and gibberellic acid (GA3)on the chemical composition of and tuberization in the potatowere studied. GA3 at 106 M inhibited and ABA at an equimolarconcentration promoted tuberization. The inhibitory effect ofGA3 was relieved by the addition of ABA. The fresh weight ofthe shoot, chlorophyll content and the total glycoalkaloidslevel were increased by GA3 treatment, but decreased by ABAtreatment. In contrast, total proteins were increased by ABA,but decreased by GA3 treatment.
1This work was supported by a PL-480 research grant (FG-Pa-262)from the United States Department of Agriculture widi co-ordinationby the Agriculture Research Council, Pakistan. (Received August 29, 1980; ) 相似文献
16.
Kamiya Yuji; Kobayashi Masatomo; Fujioka Shozo; Yamane Hisakazu; Nakayama Ishizue; Sakurai Akira 《Plant & cell physiology》1991,32(8):1205-1210
Prohexadione calcium (BX-112) is a novel plant growth regulatorthat inhibits the late stages of the biosynthesis of gibberellinsin plants. Fourteen kinds of gjbberellin, helminthosporol and'helminthosporic acid were applied simultaneously with BX-112to rice seedlings (Oryza sativa L. ), and their growth-promotingactivities in terms of shoot elongation were examined. The growth-promotingactivities of GA1, GA4, GA18, GA22, GA23, GA38, helminthosporoland helminthosporic acid were not inhibited by BX-112, but thoseof GA5, GA9, GA15, GA19, GA20, GA31, GA44 and GA53 were inhibited.These results suggest that 3ß-hydroxylation is animportant and necessary step in the biosynthesis of gibberellinsthat promote shoot elongation in rice seedlings. The weak promotionof shoot elongation by GA22 in the presence of BX-112 suggeststhat the effect of a hydroxyl group at C-18 of GA22 might beable to mimic the effect of the 3ß-hydroxyl groupof GA1. Helminthosporol and helminthosporic acid may promotethe shoot elongation of rice by mimicking physiologically activegibberellins and not by stimulating their biosynthesis.
1Part I is the previous paper by Nakayama et al. (1990a)
3Present address: Frontier Research Program RIKEN, Wako-shi,Saitama, 351-01 Japan. (Received June 26, 1991; Accepted September 4, 1991) 相似文献
17.
Kawaguchi Masayoshi; Imaizumi-Anraku Haruko; Fukai Shungo; Syono Kunihiko 《Plant & cell physiology》1996,37(4):461-470
We studied the effects of several plant-growth regulators onthe induction of nodule-like structures on roots of Lotus japonicus,which has been proposed as a candidate for a leguminous plantfor molecular genetic analysis. Contrary to our expectations,the addition of gibberellin A3 (GA3) at concentrations of 10-4M to 10-4 M resulted in the formation of nodule-like structureson roots when seedlings were plated on nitrogen-free Fahraeusagar medium. GA4 also induced such outgrowths but was less activethan GA3. Application of an inhibitor of auxin transport, N-(1-naphthyl)-phthalamicacid (NPA) and of kinetin, which have been reported to inducepseudonodules in other legumes, had no effect on L. japonicus.Microscopic observations showed that GA3-induced nodule-likestructures were caused by cell divisions within the pericycleon the roots. In addition, the outgrowths elicited by GA3 couldbe completely suppressed by the addition of 15 mM potassiumnitrate or ammonium nitrate. These results show that the pericyclecells of the roots of L. japonicus are specifically sensitiveto gibberellins and that potential for cell division might bemodulated by nitrogen compounds. We also examined the effectsof ancymidol and uniconazole [S-3307; (E)-1-(4-chIorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-ol],two synthetic plant-growth retardants. Both compounds at 3 x10-5 M significantly increased the number of stunted lateralroots. The unusual branching could not be counteracted by theexogenous addition of GA3 but by 10-6 M brassinolide. We discussthe physiological role of brassinolide in the initiation oflateral roots. (Received August 4, 1995; Accepted March 11, 1996) 相似文献
18.
Under conditions of apoplastic unloading from the sieve element-companioncell (se-cc) complexes in fully-elongated stems of Phaseolusvulgaris plants, gjbberellic acid (GA3 stimulated in vitro uptakeof [14C]sucrose by the stem tissues. The GA3, response dependedupon the incubate containing calcium ions and being bufferedat pH 6. The GA3 action could be accounted for by a reductionin the Michaelis-Menten constant of the uptake process. Promotedtransport by GA3 in the decapitated stems resulted in all thetissues accumulating higher levels of [14C]photosynthates. Comparisonof this response with that for in vitro uptake of [14C]sucroseindicated that GA3 stimulation of the sucrose uptake processcontributed significantly to the accumulation of photosynthatesby the pith alone. The bulk of enhanced photosynthate accumulationby the remaining stem tissues can be accounted for by a GA,-inducedelevation of the apoplast sucrose concentration. In terms ofonset and change in rate, the time-course kinetics of GA3 stimulationof [14C]photosynthate transport and of in vitro [14CJsucroseuptake were found to be similar. It is proposed that GA3 promotionof photosynthate accumulation by the pith tissues is a minorcontributing factor to GA3 regulation of phloem translocation Phaseolus vulgaris L., french bean, stem, assimilate transport, gibberellic acid, rink accumulation 相似文献
19.
The growth and IAA-oxidase activity of light-grown cucumber seedlings (cv. Aonagajibae) were investigated in response to GA3 and IAA. Both GA3 and IAA induced significant elongation of the hypocotyl. The fresh and dry weights of the hypocotyl increased due to GA3 or IAA treatment, whereas no significant change was observed in the cotyledons of GA3-treated seedlings as compared with the controls. The fresh and dry weights of IAA-treated cotyledons were both lower than those of controls. Treatment with GA3 or IAA resulted in retardation of IAA-oxidase activity in the hypocotyl and cotyledons. The degree of retardation was less in the cotyledons than in the hypocotyl. An inverse relationship was recognized between GA3- or IAA-induced elongation and IAA-oxidase activity in the hypocotyl. The auxin-mediated mechanism for gibberellin action was discussed. 相似文献
20.
Effect of gibberellic acid on starch content of soybean (Glycine max L.) and its correlation with extension growth 总被引:1,自引:0,他引:1
This investigation was undertaken to study the effect of GA3on extension growth of Glycine max L. and on starch contentof its individual internodes at maturity. The effect on hydrolyticactivity of the extract of different internodes was also studied.GA3 stimulates the extension growth of stem by increasing theelongation of those internodes which are either in the processof elongation or being differentiated at the time of treatment.Starch content decreases with the position of the internode(from base upwards) on the intact plant. Corresponding internodeshave minimum starch content in 100 ppm GA3-treated plants andmaximum in the controls. Internodes which show the maximum elongationdue to GA3 treatment, show the least starch content and alsoshow maximum hydrolytic activity during the period of elongation.It is suggested that enhanced extension growth is brought aboutby enhanced mobilization of reserve food by GA3. (Received November 21, 1967; ) 相似文献