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1.
A reduction in concentration of gibberellins has been implicated in the phase change from juvenile to mature forms of ivy (Hedera helix L.). Attempts were made to increase the effective internal concentration of gibberellins by exogenous application of GA3, and to decrease them by various applications of abscisic acid (ABA) and paclobutrazol (PP333), alone or in combination with GA3. ABA and GA3 were fed directly into the xylem of ivy plants by a wick system (a less drastic procedure than the defoliation or decapitation used by earlier workers) whereas PP333 was applied as a soil drench.Mature ivy responded to the application of GA3 by reversion to the juvenile form, although this reversion was incomplete with respect to leaf lobing and red (anthocyanin) pigmentation and could occur spontaneously without the application of GA3. Contrary to expectation, applications of ABA and PP333 caused the stimulation of growth in juvenile ivy. No adult characteristics were induced. As similar concentrations of ABA and PP333 produced severe retardation of growth (which could be alleviated by the application of GA3) in other species, it is suggested that ivy may be an unsuitable model system for the investigation of phase change in woody plants. 相似文献
2.
Phase Change in Hedera helix: Induction of the Mature to Juvenile Phase Change by Gibberellin A3 总被引:1,自引:0,他引:1
A sensitive and reproducible method to obtain GA3 induced morphological reversion of mature Hedera helix to the juvenile form has been developed. Dose response experiments indicate that GA3 stimulates reversion over a 50–100 fold range with a half maximal response at approximately 0.5 μg GA3 per plant. The individual characteristics involved in phase change revert to the juvenile form in a sequential manner as GA3 dose is increased. Variations in light intensity from 1.2–3.6 × 104 lux and temperature from 15 to 26°C do not affect this hormonal response. Other growth regulators including indoleacetic acid, kinetin, abscisic acid and (2-chloroethyl)phosphonic acid (Ethephon) are inactive but other gibberellins (GA1 and a mixture of A4–A7) are active in stimulating reversion. Therefore, the response is specific for gibberellins as a class of hormones but non-specific for a particular form of gibberellin. The significance of this response in relation to juvenility in woody plants is discussed. 相似文献
3.
Control of protein synthesis in barley aleurone layers by the plant hormones gibberellic acid and abscisic acid 总被引:25,自引:0,他引:25
The patterns of protein synthesis in barley aleurone layers treated with gibberellic acid (GA3) and abscisic acid (ABA) are compared with the patterns observed in wheat germ in vitro translation assays directed by RNA isolated from similarly treated layers. When used alone, GA3 and ABA both induce the formation of new translatable mRNAs and cause new proteins to be synthesized. The effects of GA3 are more dramatic than those of ABA. In GA3-treated tissues, overall protein synthesis is redirected to produce large quantities of α-amylase and a few other GA3-induced proteins, while other protein synthesis is reduced or stopped. Large amounts of new translatable mRNA for α-amylase are also induced such that the dominant in vitro translation product is α-amylase. These changes are blocked by the simultaneous addition of ABA to the tissue. In GA3 plus ABA-treated layers, few changes in protein synthesis in vivo are observed when compared to protein synthesis in untreated tissue, although the induction of mRNA for α-amylase and the other GA3-induced mRNAs does occur. This indicates that ABA does not interfere with GA3 induction of translatable mRNAs but prevents the translation of these mRNAs in vivo. Thus ABA and potentially GA3 regulate the translation of proteins in vivo in barley aleurone layers. 相似文献
4.
Phase Change in Hedera helix L.: III. THE EFFECTS OF GIBBERELLINS, ABSCISIC ACID AND GROWTH RETARDANTS ON JUVENILE AND ADULT IVY 总被引:1,自引:0,他引:1
Gibberellic acid, applied to delaminated petioles of rootedcuttings of juvenile and adult ivy initially induced internodeelongation and abnormal leaf development, and suppressed apicaldominance. Juvenile cuttings were affected only transientlyand soon reverted to normal growth. Adult cuttings, insteadof resuming normal growth after this initial response to GA3,gradually developed many juvenile characteristics. Approximately16 weeks after treatment at 25 ?C nearly all shoots of adultcuttings had undergone complete rejuvenation. Lower temperaturereduced the speed of response to GA3. A mixture of gibberellinsA4 and A7 had effects similar to those of GA3 on the growthof juvenile and adult cuttings. Treatment of both phases ofivy with abscisic acid (ABA) induced no visible effects andwhen ABA was applied with GA3 it did not reduce the responseof either phase to the gibberellin. CCC had a marked dwarfingeffect on juvenile ivy but did not induce pre-maturation. However,extraction of gibberellin-like substances from severely dwarfedplants suggested that CCC was not exerting its growth retardingeffect through an inhibition of gibberellin biosynthesis. AMO1618 did not retard growth of juvenile ivy cuttings. 相似文献
5.
Stimulation of α-amylase activity was observed in Porteresia coarctata immature seeds (20-day-old) when de-embryonated prewashed half seeds were incubated in media containing gibberellic acid (GA3, 10?5M). No such activity was observed in mature seeds even when GA3 concentration was increased up to five fold. ABA suppressed the GA3 enhanced α-amylase synthesis up to nearly 70% in the immature seeds. Absence of this enzyme activity in mature seeds may be due to high levels of ABA. The immature aleurone showed a 23 kD polypeptide induced by ABA. 相似文献
6.
Tetsushi Azuma Tomoko Hatanaka Naotsugu Uchida Takeshi Yasuda 《Plant Growth Regulation》2003,41(2):105-109
The enhancement of internodal elongation in floating or deepwater rice (Oryza sativa L. cv. Habiganj Aman II) by treatment with ethylene or gibberellic acid (GA3) at high relative humidity (RH) is inhibited by abscisic acid (ABA). Here, we examined the interactive effects of ethylene, gibberellin (GA) and ABA at low RH on internodal elongation of deepwater rice stem segments. Although ethylene alone hardly promoted internodal elongation of stem sections at 30% RH, it enhanced the internodal elongation induced by GA3. Application of ABA alone to stem segments had no effect on internodal elongation. However, in the presence of ethylene and GA3 at 30% RH, ABA further promoted internodal elongation. This promotive effect of ABA was not found in the internodes of stem segments treated either with ethylene or with GA3 at 30% RH or in the internodes of stem segments treated with ethylene and/or GA3 at 100% RH. 相似文献
7.
Effects of abscisic acid on the orientation and cold stability of cortical microtubules in epicotyl cells of the dwarf pea 总被引:1,自引:0,他引:1
Summary The effects of abscisic acid (ABA) on the orientation and cold stability of cortical microtubules (MTs) in epidermal cells of epicotyls of the dwarf pea,Pisum sativum L. cv. Little Marvel, were examined by immunofluorescence microscopy. The effect of ABA on the elongation of epicotyls and on the orientation of cortical MTs was opposite to that of gibberellin A3 (GA3). Treatment with ABA, which reduced the promotion of epicotyl elongation by GA3, eliminated the GA3-induced predominance of transverse MTs and resulted in a predominance of longitudinal MTs. The effect of ABA on the cold stability of cortical MTs was also opposite to that of GA3. ABA increased the cold stability of MTs, while GA3 decreased it. The predominance of longitudinal MTs brought about by ABA may have some relationship to ABA-induced inhibition of the elongation of the epicotyl. ABA may alter membrane proteins to stabilize cortical MTs and induce cold hardiness of plants.Abbreviations ABA
abscisic acid
- DMSO
dimethylsulfoxide
- FITC
fluorescein isothiocyanate
- GA3
gibberellin A3
- MT
microtubule
- PBS
phosphate-buffered saline
Dedicated to the memory of Professor Oswald Kiermayer 相似文献
8.
The effects of GA3 and/or ABA on the α-amylase activity and the ultrastructure of aleurone cells in halves of seeds without embryos (embryo-less
half seeds) of oats (Avena sativa L.) were studied.
α-Amylase activity was detected by the starch-agar gel method in the aleurone layers of embryo-less half seeds soaked in 1
μM GA3 solution or 100 μM GA3+10 μM ABA solution but not in those of seeds soaked in distilled water, 10 μM ABA solution, or 1 μM GA3+10 μM ABA solution. Ultrastructural examinations of aleurone cells with α-amylase activity showed a decrease in the number
of sphaerosomes, the appearance of flattened saccules pressed to the surface of aleurone grains, and the development and transformations
of the rER from a slender form to the one with wide inner spaces. In the aleurone cells in which the enzyme activity was not
detected, components of the rER showed only slender profiles. The number of sphaerosomes did not decrease, and no flattened
saccules appeared in the aleurone cells treated with 10 μM ABA or 1 μM GA3+10 μM ABA. 相似文献
9.
M. Gomathinayagam V. E. Anuradha Changxing Zhao Gloria A. Ayoola C. Abdul Jaleel R. P. Anneerselvam 《Frontiers of Biology in China》2009,4(3):337-341
In this study, 5 μmol·L−1 abscisic acid (ABA) and gibberellic acid (GA3) were used to study the effect of both growth regulators on the morphological parameters and pigment composition of Andrographis paniculata. The growth regulators were applied by means of foliar spray during morning hours. ABA treatment inhibited the growth of
the stem and internodal length when compared with control, whereas GA3 treatment increased the plant height and internodal length. The total number of leaves per plant decreased in the ABA-treated
plants, but GA3 treatment increased the total number of leaves when compared with the control. Both growth regulators (ABA and GA3) showed increased leaf area. ABA and GA3 treatments slightly decreased the total root growth at all the stages of growth. The growth regulator treatments increased
the whole plant fresh and dry weight at all stages of growth. ABA enhanced the fresh and dry weight to a larger extent when
compared with GA3. An increase in the total chlorophyll content was recorded in ABA and GA3 treatments. The chlorophyll-a, chlorophyll-b, and carotenoids were increased by ABA and GA3 treatments when compared with the control plants. The xanthophylls and anthocyanin content were increased with ABA and GA3 treatments in A. paniculata plants. 相似文献
10.
Hemant Pandey Shyamal K. Nandi Bhuwan Chandra Mohammad Nadeem Lok Man S. Palni 《Acta Physiologiae Plantarum》2001,23(4):467-474
Podophyllum hexandrum Royle, an important alpine herb, is the source of highly valued podophyllotoxin. The effect of some plant growth substances
(GA3, BAP & ABA), uniconazole (an inhibitor of GA biosynthesis), and a combination of GA3 and uniconazole were examined in respect to influence on sprouting in rhizomes of P. hexandrum and on induction of flowering at a lower altitude. Amongst the various chemicals tested, GA3 had a marked effect resulting in uniform sprouting and also induced flowering in about half of the treated rhizomes. While
BAP also promoted early sprouting, delayed sprouting was seen in rhizomes treated with ABA. Uniconazole treatment, either
alone or with GA3 was found to inhibit flowering and also resulted in reduced plant height. GA3 treatment of rhizomes from plants that was maintained for up to 30 months at a lower altitude also induced flowering thus
replacing the normal chilling requirement of plants. These results suggest that treatment of GA3 could be effectively used for inducing uniform sprouting and flowering in rhizomes of P. hexandrum grown at lower altitudes. 相似文献
11.
A significant depression of callus growth resulted from low concentrations of abscisic acid (ABA) added to the medium recommended by Linsmaier and Skoog. Low concentrations also decreased the chlorogenic acid and lignin content of the callus, and generally decreased amounts of scopolin and scopoletin in the tissue. Gibberellic acid (GA3) stimulated callus growth in a low concentration (0.1 mg/1) and inhibited growth at a high concentration (10.0 mg/1). Both levels of GA3 increased scopoletin accumulation in tobacco callus. A high concentration of GA3 increased the accumulation of scopolin and chlorogenic acids, whereas a low concentration decreased the amounts of these two phenolic compounds. In comparison with the control, lignin synthesis was stimulated by a low GA3 concentration, but a high GA3 concentration did not have a significant effect. Both low and high concentrations of GA3 overcame ABA inhibition of growth and lignin synthesis, and partially reversed ABA inhibition of scopoletin production. However, GA3 did not reverse the inhibitory effect of ABA on scopolin production. The low concentration of GA3 overcame the inhibition of chlorogenic acid production resulting from a 0.01 mg/1 concentration of ABA, but this was the only reversal of chlorogenic acid inhibition resulting from addition of GA3 to the medium. 相似文献
12.
L. V. Kovaleva E. V. Zakharova Yu. V. Minkina G. V. Timofeeva I. M. Andreev 《Russian Journal of Plant Physiology》2005,52(4):521-526
The data obtained characterize the changes in the contents of endogenous phytohormones (IAA, cytokinins, GA, and ABA) in germinating pollen grains and growing pollen tubes of a self-compatible clone of petunia (sPetunia hybrida L.) within an 8-h period under in vitro conditions. The hydration and initiation of germination of pollen grains brought the ABA content down to a zero level, while the levels of GA, IAA, and cytokinins increased 1.5–2-fold. Later, in the growing pollen tubes, the GA content increased twofold, while the levels of IAA and cytokinins decreased. The exogenous ABA and GA3 considerably promoted pollen germination and pollen tube growth; however, only the treatment with GA3 produced the maximum length of pollen tubes. The exogenous IAA promoted and the exogenous cytokinins hindered the growth of pollen tubes. The membrane potential, as assessed with a potential-sensitive dye diS-C3-(5), considerably increased in the pollen grains treated with ABA and benzyladenine, whereas IAA and GA3 did not practically affect it. The authors conclude that the mature pollen grains contain the complete set of hormones essential for pollen germination and pollen tube growth. ABA, GA, and IAA together with cytokinins control the processes of pollen grain hydration, germination, and pollen tube growth, respectively.__________Translated from Fiziologiya Rastenii, Vol. 52, No. 4, 2005, pp. 584–590.Original Russian Text Copyright © 2005 by Kovaleva, Zakharova, Minkina, Timofeeva, Andreev. 相似文献
13.
Nehemia Aharoni 《Journal of Plant Growth Regulation》1989,8(4):309-317
The interrelationship between ethylene and growth regulators in the senescence of romaine lettuce (Lactuca sativa L.) leaves was studied. Gibberellic acid (GA3), kinetin, and 3-indoleacetic acid (IAA) retarded chlorophyll loss from leaf discs which were floated on hormone solutions. Abscisic acid (ABA) and ethephon enhanced chlorophyll loss and antagonized the senescence-retarding effect of GA3 and kinetin. A high concentration of IAA (10–4 M) caused accelerated chlorophyll loss, whereas a similar concentration of kinetin neither retarded nor promoted chlorophyll loss. The ineffectiveness of IAA and kinetin at their supraoptimal concentrations in retarding leaf senescence was related to increased production of ethylene induced in the treated leaf discs. GA3 was the most effective in retarding chlorophyll loss and did not stimulate ethylene production at all. The senescence-enhancing effect of ABA was not mediated by ethylene. However, the moderately increased production of ethylene, induced by relatively high concentrations of ABA, could act synergistically with the latter to accelerate chlorophyll loss. It is proposed that the effectiveness of exogenously applied hormones, both in enhancing and retarding senescence, is greatly affected by the endogenous ethylene concentration of the treated plant tissue.Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel, No. 2571-E, 1988 series. 相似文献
14.
The gibberellins GA1, GA3, GA4, GA7, GA9 and GA20 were quantified in vegetative and pollen cone buds of juvenile and mature trees of Pinus radiata by combined gas chromatography-mass spectrometry and selected ion monitoring (GC-MS-SIM) using deuterated GAs as internal standards. Higher levels of GA7 and GA9 and lower levels of GA4 were detected in juvenile vegetative buds compared to mature buds, and there were no differences in relation to age for GA1, GA3 and GA20. Conversely, when differences between vegetative and pollen cone buds from a mature tree were studied, the highest levels of GA1 and GA4 were found in pollen cone buds, similar levels of GA3, GA7 and GA9 were observed in both, and ten fold lower levels of GA20 were found in pollen cone buds as compared with vegetative buds. These results indicate a difference in GA metabolism in relation to both the tree age as well as the physiological status of buds: vegetative or reproductive in this conifer. 相似文献
15.
Four different plant growth regulators, gibberellic acid (GA3), naphthaleneacetic acid (NAA), benzyladenine (BA) and abscisic acid (ABA), were individually mixed in a lanolin paste and applied to immature fruit on grapefruit trees beginning soon after fruit set. The treated fruit was allowed to mature on the tree. Application of 1000 ppm GA3 in this manner generally increased fruit size, decreased the concentration of the total acid in the juice and decreased the concentration of naringin in the juice sacs compared to that of the controls. GA3 increased the total soluble solids (brix) in the juice in some experiments. Treatment of fruit with 1000 ppm ABA and BA significantly decreased the size of the fruit and increased the naringin concentration, but had variable effects on the soluble solids content and the acid content. Treatment with 1000 ppm NAA did not produce any significant changes in size, acid content, brix or naringin concentration.RetiredReference to a company or product name does not imply approval or recommendation of the product by the U.S. Department of Agriculture to the exclusion of other products that may be suitable. 相似文献
16.
Gibberellin A3 and Abscisic Acid Cause the Reorientation of Cortical Microtubules in Epicotyl Cells of the Decapitated Dwarf Pea 总被引:1,自引:0,他引:1
To determine whether or not the changes in the orientation ofmicrotubules (MTs) that are induced by GA3 and ABA result fromchanges in the rate of epicotyl elongation caused by these hormones,we examined the effects of GA3 and ABA on the orientation ofMTs in epidermal cells of decapitated epicotyls of the dwarfpea (Pisum sativum cv. Little Marvel), in which neither GA3nor ABA causes changes in the rate of epicotyl elongation. Cuttings taken from GA3-pretreated seedlings were decapitatedand treated with ABA. ABA eliminated the GA3-induced predominanceof transverse MTs and treatment with ABA resulted in a predominanceof longitudinal MTs in the decapitated cuttings. However, ABAdid not reduce the rate of epicotyl elongation in these samples.Cuttings taken from ABA-pretreated seedlings were decapitatedand treated with GA3. GA3 caused the orientation of MTs to changefrom longitudinal to transverse in the decapitated cuttings.However, GA3 had no promotive effect on elongation of theseepicotyls. The results indicate that both ABA and GA3 have the abilityto change the orientation of MTs by mechanisms that do not involvechanges in the rate of cell elongation. (Received August 18, 1992; Accepted January 18, 1993) 相似文献
17.
Experiments with Grand Rapids lettuce seeds (Lactuca sativa L.) maintained in darkness or irradiated with red light have shown that the inhibition of germination induced by low concentrations of ABA (2, 4, 6 μM) could be overcome by gibberellins (GA3 or GA4). The same results were obtained, although to a lesser extent, under the influence of two out of the four cytokinins tested (K and BAP) for seeds maintained in darkness. To suppress the block induced by higher concentrations of ABA (for example 8 μM), it was necessary to apply a cytokinin (K, BAP, Z or 2iP) and a gibberellin (GA4 or GA3) simultaneously, or a cytokinin following a red light treatment. Experiments conducted in darkness in which ABA (8 μM) was applied together with a cytokinin (BAP) and a gibberellin (GA4) showed that the gibberellin and the cytokinin played similar roles towards each other and towards ABA. 相似文献
18.
When applied to spurs of mature Prunus avium before floral initiation, gibberellins GA1, GA4 and GA3 inhibited floral initiation by 9–17%, GA7 by 43%, GA3 by 65–71% and 2,2-dimethyl GA4 by 78%. GA9 and GA20 were inactive. Thus activity only of the GAs with a C-3 hydroxyl was increased markedly by a double bond in the C-1,2 or C-2,3 position, and activity increased with increasing hydroxylation. None of the GAs affected the total number of buds (vegetative and floral) surviving in the spur. Measured by the threshold dose required for activity, seedling shoot growth responses to GA3, GA7, GA1 or GA4 resembled those of floral initiation, but di-methylation of GA4 at C-2 had no effect, and GA9 was as active as GA7. Mature shoots, including those on rooted cuttings, were less responsive to GA treatment than were juvenile shoots, with terminal shoots on mature trees more responsive than spur shoots. Spur shoot growth on mature trees responded to GA3 and to a lesser extent GA7, but not to GA1 or GA4. However, all these GAs promoted the growth of terminal shoots on mature trees to similar extents, whereas 2,2-dimethyl GA4 was less active than GA4 The differences between juvenile and mature shoot growth in sensitivity to a C-1,2 or C-2,3 double bond, and between mature shoot growth and floral initiation in GA-structure requirements, indicate that phase change alters the GA complement and/or GA receptor/transduction mechanisms of P. avium. The difference in sensitivity to 2,2-dimethyl GA4 indicates that floral initiation and growth have different requirements for GA transport and/or action. 相似文献
19.
Embryos isolated from dormant apple seeds were treated with jasmonic acid (JA), gibberellin A3 (GA3), abscisic acid (ABA) and hydrogen cyanide in darkness and in light. The chemicals were present in the culture medium continuously and simultaneously or applied for 2 days and in different sequences. All treatments stimulated embryo germination except ABA, which was strongly inhibitory. Additive effects of JA with light and with GA3 on embryo germination were observed, whereas ABA interacted synergically with JA, HCN and light. ABA and GA3 were most effective when applied early during embryo incubation, but the late JA treatment was more stimulatory. It is concluded that JA does not act on the regulatory pathway that is initiated by light and which leads to embryo germination through gibberellin accumulation and alkaline lipase activation. ABA and HCN appear to be involved in the control of this pathway. JA and ABA may be involved in the control of alkaline lipase activity, independently of this regulatory chain.Abbreviations ABA
abscisic acid
- GA3
gibberellin A3
- JA
jasmonic acid 相似文献
20.
In this report, B9 treatment had no effect on the growing of rosette biennialScrophularia vernalis L.; it inhibited or slowed stem elongation. Applications of GA3 to B9 treated plants produced a significant increase of stem elongation, in relation to GA3 treated plants. Plants treated with only GA3 failed to flower; otherwise, the flowering of vernalized plants was not altered by GA3. Thus, B9 effect on flowering was tested by using GA3. B9 by itself induced flowering, it increased inflorescence formation in vernalized plants without altering stem growth pattern in the most of cases. The induction or the stimulation of flowering brought about by B9 was not reversed by GA3; we may thus hypothesize that flowering by B9 oannot be traced back to gibberellin biosynthesis. 相似文献