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1.
Combinations of far-red light (FR) (4 min) and gibberellic acid (GA3), given at the beginning of a daily 12-h dark period in a growth room, were used to study floral induction in four maturity genotypes of the milo group of sorghum (Sorghum bicolor (L.) Moench). The 12-h dark period without GA3 application or FR induced flowering in only the early genotype; FR hastened initiation in the early genotype, while GA3 hastened floral initiation in the two intermidiate-flowering genotypes. GA3 and FR together had a strong synergistic effect, hastening floral initiation by 30 to more than 80 d in the early and intermediate genotypes. Red light (R) did not hasten flowering; FR preceded by R gave the same effect as FR alone. GA3 promoted stem elongation equally whether floral initiation occurred or not; thus, its effect on stem elongation was independent of floral initiation. The capacity of GA3 to induce flowering in sorghum, a short-day plant, seems to be enhanced by phytochrome being in the PR form at the beginning of the night when GA3 was applied.Abbreviations FR
far-red light
- GA(s)
gibberellin(s)
- GA3
gibberellic acid
- R
red light 相似文献
2.
L. Wijayanti S. Fujioka M. Kobayashi A. Sakurai 《Journal of Plant Growth Regulation》1997,16(2):115-119
The involvement of abscisic acid (ABA) and indole-3-acetic acid (IAA) in the regulation of flowering of Pharbitis nil was investigated through exogenous applications and analyses of endogenous levels. Both hormones inhibited the flowering
of P. nil when they were applied before or after a single 15-h dark treatment. The inhibitory effect of ABA and IAA was significant
when they were applied before the dark treatment, and the application to plumules was more effective than that to cotyledons.
In all applications, the inhibitory effect of IAA was stronger than that of ABA. Endogenous levels of ABA and IAA in the plumules
were compared between flower-inductive (15-h dark treatment) and noninductive (continuous light) light conditions. There was
no significant difference in the ABA level between light and dark conditions, whereas the level of IAA was decreased by the
dark treatment. These results suggest that biosynthesis and/or catabolism of IAA is affected by the light treatment and therefore
may be involved in the regulation of early flowering processes in the apex. The inhibitory effects of ABA and IAA were reversed
by an application of gibberellin A3, indicating that gibberellin A3 counteracts the flowering processes affected by ABA and IAA. Application of aminoethoxyvinylglycine restored the flowering
response inhibited by IAA, which suggests the possibility that the inhibitory effect of IAA is the result of enhanced ethylene
biosynthesis.
Received November 22, 1996; accepted February 17, 1997 相似文献
3.
The role of cytokinins in the promotion of flowering in the endangered species Kniphofia leucocephala Baijnath. was investigated using shoots maintained in culture for 3 years. The highest percentage flowering (65%) was obtained on media containing 20 μM benzyladenine (BA). The inclusion of isopentenyladenine and zeatin in the media also resulted in flowering, but these treatments were less effective than BA in inducing flowering. The effect of cytokinins on flowering was dose-dependent, with high concentrations of BA inhibiting flower formation. Treatments that resulted in rooting of explants produced no flowers. The resulting inflorescences in all treatments did not mature and senesced prematurely, even when gibberellic acid (GA3) was applied post-flower-emergence. 相似文献
4.
Shozo Fujioka; Isomaro Yamaguchi; Murofushi Noboru; Takahashi Nobutaka; Kaihara Sumiko; Takimoto Atsushi 《Plant & cell physiology》1983,24(2):241-246
The effects of plant hormones on flowering of Lemna paucicostata151 and 381 were investigated when exogenously applied in combinationwith benzoic acid. These strains are very sensitive to benzoicacid and flower readily on application of benzoic acid. Theflower-inducing effect of benzoic acid was strongly modifiedby plant hormones: gibberellins, indole-3-acetic acid and abscisicacid were inhibitory, while cytokinins were promotive (synergistic),suggesting that the balance between endogenous levels of benzoicacid and plant hormones contributes to the regulation of floweringin Lemna. (Received October 6, 1982; Accepted December 23, 1982) 相似文献
5.
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
6.
《Bioscience, biotechnology, and biochemistry》2013,77(5):852-853
The role of endogenous gibberellin (GA) in the flowering of the short-day plant, Pharbitis nil, was investigated by using uniconazole, which is a specific inhibitor of GA biosynthesis. Both the endogenous GA level and flowering response decreased with increasing concentration of uniconazole applied via the roots. The strongest inhibition of flowering was observed when uniconazole was applied one day before a 15-h dark treatment. The inhibition by uniconazole was overcome by an application of GAs to the plumules, the order of effectiveness of the endogenous GAs in P. nil being GA1 ≧GA20>GA19≧GA44>GA53»GAH. This is the first report of the correlation between the endogenous GA level and flowering response in P. nil. It was found that endogenous GAs were required for the flowering of P. nil during or just after the dark period. 相似文献
7.
Two foliar applications of gibberellic acid (GA3, 250 mg l–1) enhanced the flowering in various clones of Papaver bracteatum. The most pronounced effects were obtained in late flowering clones in which GA3 increased significantly the number and weight of the capsules and thebaine yield per plant.Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel, No. 1267-E, 1984 series. 相似文献
8.
The restricted flowering of colored cultivars ofZantedeschia is a consequence of developmental constraints imposed by apical dominance of the primary bud on secondary buds in the tuber,
and by the sympodial growth of individual shoots. GA3 enhances flowering inZantedeschia by increasing the number of flowering shoots per tuber and inflorescences per shoot. The effects of gibberellin on the pattern
of flowering and on the developmental fate of differentiated inflorescences along the tuber axis and individual shoot axes
were studied in GA3 and Uniconazole-treated tubers. Inflorescence primordia and fully developed (emerged) floral stems produced during tuber
storage and the plant growth period were recorded. Days to flowering, percent of flowering shoots and floral stem length decreased
basipetally along the shoot and tuber axes. GA3 prolonged the flowering period and increased both the number of flowering shoots per tuber and the differentiated inflorescences
per shoot. Activated buds were GA3 responsive regardless of meristem size or age. Uniconazole did not inhibit inflorescence differentiation but inhibited floral
stem elongation. The results suggest that GA3 has a dual action in the flowering process: induction of inflorescence differentiation and promotion of floral stem elongation.
The flowering pattern could be a result of a gradient in the distribution of endogenous factors involved in inflorescence
differentialtion (possibly GAs) and in floral stem growth. This gradient along the tuber and shoot axes is probably controlled
by apical dominance of the primary bud.
Online publication: 7 April 2005 相似文献
9.
Fouad Mohamed Harry Jan Swartz J. George Buta 《Plant Cell, Tissue and Organ Culture》1991,25(1):75-84
Plant growth regulators applied in vitro affected strawberry plant performance ex vitro for a period of up to 4 months. Benzyl-adenine and gibberellin enhanced juvenile characteristics; in general, more runners and monofoliolate leaves were produced, net photosynthesis was reduced, leaf diffusive resistance was increased and, on occasion, flowering was delayed. In contrast, abscisic acid and a gibberellin biosynthesis inhibitor, paclobutrazol, resulted in a more adult phenotype; specifically, flowering was earlier, net photosynthesis and leaf diffusive resistance rates were equal to those of adult plants, and fewer leaves were monofoliolate. Tissue culture-produced plants reacquire the adult phenotype earlier than seedlings mature. Abscisic acid application to seedlings also resulted in earlier and increased flowering.Endogenous abscisic acid concentrations were greater in adult plants and less in tissue culture and seedling plants at 3 and 7 weeks ex vitro, after germination or after adult runner propagation. No flowering occurred at 3 weeks in any propagation type and only runner-produced plants flowered at 7 weeks. At 15 weeks, no statistical difference in abscisic acid concentrations existed among propagation treatments and all propagation types flowered. The endogenous concentrations of abscisic acid in plants propagated by all three methods were much higher at three weeks compared to concentrations at 7 or 15 weeks.Abbreviations ABA
+cis, trans-abscisic acid
- BA
benzyl-adenine
- GC-SIM-MS
combined gas chromatography-selected ion monitoring mass spectrometry
- GA
gibberellin A3
- RS
leaf diffusive resistance in sec cm-1
- MS
Murashige & Skoog medium devoid of plant growth regulators
- Pn
net photosynthesis in mol CO2 fixed m-2 sec-1
- paclo
paclobutrazol as 50WP
- TC-plants
plants produced from tissue culture
- Tween20
polyoxyethylene-sorbitan monolaurate
- RP
runner plants
- SDLG
selfed seedlings 相似文献
10.
11.
The effect of applied arachidonic acid, prostaglandin (PGE1) and various sterols and combinations of arachidonic acid + sterols, on flowering of Pharbitis nil were ascertained by using a tissue culture technique. It was found that arachidonic acid, PGE1 stigmasterol, testosterone, cholesterol, stigmasterol + arachidonic acid, -sitosterol + arachidonic acid and cholesterol + arachidonic acid all caused earlier flowering. Four inhibitors of prostaglandin biosynthesis (gentisic acid, acetylsalicylic acid, salicylic acid and oleic acid), inhibited flowering completely. The results confirm that the compounds tested could possibly play a role in the flowering of P. nil. 相似文献
12.
Gibberellic acid (GA,), chlorflurenol and ethrel were applied at different concentrations to either male or female trees of Myrica esculenta. GA3 induced intersexual flowers both on the male and female trees whereas chlorflurenol and ethrel induced similar (intersexual) flowers but only on the male plants. When GA3 was applied in combination with chlorflurenol, fewer intersexual inflorescences appeared on the male plants along with a significant decline in the number of flowers per inflorescence. In combination, chlorflurenol and ethrel induced copious female and intersexual inflorescences per male plant, especially when two successive treatments of 100 mg/I of chlorflurenol and 1920 mg/l of ethrel were applied. The induced female inflorescences later bore fruits. 相似文献
13.
Effects of plant hormones indole-3-yl-acetic acid (IAA), gibberellic acid (GA), benzylaminopurine (BAP), abscisic acid (ABA) and ethrel (ETH) in 5 M concentration on gas exchange, ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCO, EC 4.1.1.39) activity, pigment content and yield in cotton (Gossypium hirsutum L. cv. H-777) under drought were studied. At reproductive stage (55 – 60 d after sowing) these hormones were sprayed on shoots one day prior to stress imposition by withholding irrigation. The soil moisture of control plants was kept at field capacity. Net photosynthetic rate (PN), stomatal conductance (gs), transpiration rate (E), carboxylation efficiency (CE), water use efficiency (WUE), RuBPCO activity, boll number per plant, seed number per plant and lint mass per plant significantly decreased at drought while chlorophyll (Chl) b content and flower number per plant increased. ABA and ETH significantly reduced gas exchange parameters, Chl a and Chl b content. Detrimental drought effect on PN, gs, E, CE, RuBPCO and lint mass per plant was significantly alleviated by BAP and also its effect on seed number and lint mass per plant was significantly alleviated with the ABA treatment. 相似文献
14.
Applications of the growth promotive gibberellins (GAs) GA4 and 2,2-dimethyl GA4, and of C-16,17 endo-dihydro GA5, which is known to promote flowering while inhibiting stem growth in the long-day grass Lolium temulentum, were made to micropropagated plants of Metrosideros collina cv. Tahiti, a highly ornamental cultivar with an intermittent flowering pattern. Gibberellin A4 and 2,2-dimethyl GA4 stimulated vegetative growth both in elongating shoots, and internodes of shoots developing from buds that were quiescent at the time of GA application. Abscission of the apices of expanding shoots, a feature of mature Metrosideros plants, was inhibited by these GAs, the rejuvenation of micropropagated plantlets being enhanced. However, C-16,17 endo-dihydro GA5 differed from GA4 and 2,2-dimethyl GA4 by having no promotive effects on vegetative growth, and no inhibition of apical abscission. Notwithstanding this contrasting effect on vegetative growth, high doses of GA4 or C-16,17 endo-dihydro GA5 similarly reduced flowering on shoots to which either GA was applied. Reduced flowering in response to applied GAs is common in many woody angiosperms, and in this instance was probably the combined result of abortion of developing floral structures in quiescent buds, and a preferential inhibition of bud break for floral buds relative to vegetative buds, particularly by GA4. Finally, both C-16,17 endo-dihydro GA5 and GA4 strongly inhibited bud break in this woody angiosperm, although GA4 could initially stimulate bud break when applied to vegetative buds close to the expansion stage. The above findings, in toto, highlight the sensitivity of Metrosideros to both classes of GA in a variety of growth and development processes. 相似文献
15.
H. A. S. Hussein A. Misiha 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1979,54(1):17-25
Summary Flowering time, plant height and flower size in Petunia hybrida Hort. (multiflora type) have been genetically analysed by means of a 5 × 5 diallel cross. The results indicated that: (1) the three characters are controlled by additive-dominance polygenic systems. The contribution of the additive gene actions to the genetic variance of flowering time was relatively higher than that of dominance. The reverse situation was found for plant height and flower size. (2) Dominance is ambi-directional for the three characters. Ratios of average dominance were in the range of partial for flowering-time, complete for plant height and overdominance for flower size. (3) Number of genes (or gene groups) controlling the characters are about 3, 3 and 5 for flowering time, plant height and flower size: respectively, (4) Heritability estimates are 0.84, 0.88 and 0.89 in the broad-sense and 0.40, 0.49 and 0.37 in the narrow-sense, for flowering time, plant height and flower size; respectively. (5) Heterosis as percent increase of the mean F1-hybrid above the higher parent, or decrease below the lower parent, was observed for flowering time (+ 9.7% to +13.3%), for plant height (–13.6% to –20.3%) and for flower size (+2.5% to +16.0%). 相似文献
16.
Nicolás F. Villacorta Helena Fernández Els Prinsen Pablo L. Bernad M. Ángeles Revilla 《Journal of Plant Growth Regulation》2008,27(1):93-98
Changes in gibberellins (GAs), indole-3-acetic acid (IAA), and cytokinins associated with the transition from vegetative growth
to reproductive growth in Humulus lupulus L. buds and leaves harvested at fortnight intervals were studied. During vegetative growth, GA1 increased gradually and the lowest content was observed during flower development. Both GA3 and GA4 showed a dramatic increase in the samples taken from the apical part of axillary branches from plants 4–5 m high, which corresponds
to the maximum vegetative development prior to macroscopically visible inflorescences. Notable increases in the cytokinins
trans-zeatin (t-Z), isopentenyladenine (iP), and the riboside and ribotide forms of iP were also obtained. The auxin, indole-3-acetic acid,
was the most abundant plant hormone, and its content was highest during vegetative growth. These results show for the first
time a relationship between endogenous hormone profiles and both vegetative and reproductive development in hop plants, which
may be relevant for future research on the control of the flowering by exogenous hormone applications. 相似文献
17.
Although much investigated, the factors constraining cereal grain protein accumulation are not well understood. As a result of the development of a new technique, new approaches to this question are now possible. A peduncle perfusion system was used to deliver a range of plant growth regulators (PGRs) and/or N solutions into barley (Hordeum vulgare) plants during the grain-filling period. The perfusion technique floods the peduncle interior with a treatment solution for periods of weeks to months, allowing the plant to take up administered substances from the perfused solution. The objectives of the present work were to determine: (1) whether some PGRs could alter the overall pattern of N allocation within barley plants, perhaps leading to higher protein accumulation in the seeds, (2) whether the addition of N through the peduncle could increase the seed N concentration even when the concentration of N in the rooting medium was high, and (3) whether or not PGR-stimulated elevations in grain protein levels and peduncle-added N increases in grain protein levels were additive. Three experiments were conducted to determine the physiological effects of (1) peduncle-administered PGRs (2) combinations of soil- and peduncle-applied N and (3) selected combinations of soil- and peduncle-administered N, and peduncle-applied PGRs on photosynthetic rate, dry matter partitioning and N accumulation of barley plants during grain filling. The first experiment tested four PGRs: abscisic acid (ABA), kinetin, gibberellic acid (GA3), and 2,4-dichlorophenoxy acetic acid (2,4-D) each at three concentrations. The second experiment tested three levels of soil N (NH4NO3) fertility, and two concentrations of peduncle-added N (urea). The third experiment tested four PGRs: ABA, kinetin, GA3, and 2,4-D with two soil N concentrations and two concentrations of peduncle-added N. ABA and 2,4-D decreased total seed weight of the perfused spike. The addition of peduncle-perfused N increased seed protein concentration and content under conditions of high soil N fertility, suggesting that seed protein accumulation is more limited by the ability of roots to take up N from the soil than by the seed to take up N from the rest of the plant. The effects of the PGRs on N allocation among plant parts varied with the amount of N available to the plant. Because it resulted in less protein stored in the flag leaf and more in the seeds, GA3 perfusion caused an overall change in the allocation of N among plant parts. Peduncle perfusion of kinetin and ABA affected some aspects of photosynthetic physiology. 相似文献
18.
Indole-3-acetic acid (IAA) strongly enhanced rooting of etiolated pea epicotyl cuttings while gibberellic acid (GA3) enhanced rooting only slightly. The promoting effects of the hormones appeared not until 14 d after the onset of treatment. When GA3 and IAA were applied together, the initiation of rooting started already after 6 d after onset of treatment. It is suggested that gibberellin plays an important role, in combination with auxin, in the initiation of root formation in Pisum cuttings.Abbreviations IAA
Indole-3-acetic acid
- GA3
Gibberellic acid 相似文献
19.
Bavrina T. V. Lozhnikova V. N. Cčulaficč L. Zhivanovich B. 《Russian Journal of Plant Physiology》2002,49(4):460-464
Green plants and plants devoid of photosynthetic pigments were compared with regard to their ability to flower under various growth conditions. Green plants of Chenopodium rubrum L. and plants treated with norflurazon SANDOZ-9789 (SAN) were grown on sucrose-containing media with or without hormones (GA3, BA, IAA, ABA) under short-day photoperiodic or continuous illumination with white, blue, or red light. Green and SAN-treated albino plants produced flowers only under short-day conditions. The flowering of green plants was independent of the presence of sucrose and hormones in the medium as well as of the light quality. The albino plants produced flowers under white and blue light but did not flower in red light. The addition of GA3 or BA to the medium induced flowering of albino plants exposed to red light. The functional interaction of photoreceptors in the flowering control is discussed. 相似文献
20.
R. A. Teutonico T. C. Osborn 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1995,91(8):1279-1283
Brassica cultivars are classified as biennial or annual based on their requirement for a period of cold treatment (vernalization) to induce flowering. Genes controlling the vernalization requirement were identified in a Brassica rapa F2 population derived from a cross between an annual and a biennial oilseed cultivar by using an RFLP linkage map and quantitative trait locus (QTL) analysis of flowering time in F3 lines. Two genomic regions were strongly associated with variation for flowering time of unvernalized plants and alleles from the biennial parent in these regions delayed flowering. These QTLs had no significant effect on flowering time after plants were vernalized for 6 weeks, suggesting that they control flowering time through the requirement for vernalization. The two B. rapa linkage groups containing these QTLs had RFLP loci in common with two B. napus linkage groups that were shown previously to contain QTLs for flowering time. An RFLP locus detected by the cold-induced gene COR6.6 cloned from Arabidopsis thaliana mapped very near to one of the B. rapa QTLs for flowering time. 相似文献