Abscisic Acid Inhibition of Gibberellic Acid and Cyclic 3',5'-Adenosine Monophosphate Induced alpha-Amylase Synthesis

1973 ◽  
Vol 29 (2) ◽  
pp. 186-189 ◽  
Author(s):  
K. A. BARTON ◽  
R. VERBEEK ◽  
R. ELLIS ◽  
A. A. KHAN
2014 ◽  
Vol 9 (8) ◽  
pp. 823-832
Author(s):  
Andrzej Zieliński ◽  
Magdalena Simlat ◽  
Tomasz Wójtowicz ◽  
Maria Moś

AbstractThe production of economically important cereals is accompanied by the phenomenon of sprouting which in naked cultivars may limit their reproduction and usability. The objective of the work is to evaluate the susceptibility to sprouting in naked oat cultivars, and to test the usefulness of sprouting indices. In the years 2008–2010 for seeds of 8 cultivars, differing in the degree of sprouting damage, the coefficient of sprouting (Cs) was determined. Germinability (GF), dynamics (GD) and average germination time (GAT) were determined for seeds germinating in the presence of abscisic acid (ABA), gibberellic acid (GA3) and under control conditions. Basing on the falling number (FN) in consecutive days of the sprouting induction, alpha-amylase activity was determined. The highest values of Cs were found in 2008, the year with the highest total rainfall and temperature. In the presence of ABA the GF decreased by 21%, the GAT was 4.7 days longer, and the GD decreased by 55% compared with other substrates. An increase in alpha-amylase activity contributed to a 50%, on average, decrease in FN at 10°C and 30°C after 48 and 24 h of incubation, respectively. In the analyzed years the greatest resistance to sprouting was found for Bullion seeds.


1984 ◽  
Vol 62 (6) ◽  
pp. 1245-1249 ◽  
Author(s):  
L. S. Kott ◽  
K. J. Kasha

Somatic embryogenesis was induced in callus previously initiated from immature embryos of barley. These cultures ranged in age from 6 weeks to 30 months. Embryoids were readily initiated from homogenized suspension-grown aggregates when plated on modified B5 media with 2,4-dichlorophenoxyacetic acid. Low concentrations (0.1 and 0.05 mg∙L−1) of abscisic acid promoted further maturation of embryoids, while gibberellic acid (1 mg∙L−1) and kinetin (0.1 mg∙L−1) were used in the media to encourage embryoid germination. The development of somatic embryoids from initiation through maturation and germination is described.


1970 ◽  
Vol 33 (3) ◽  
pp. 493-502 ◽  
Author(s):  
Sridhar Gutam ◽  
Virendra Nath ◽  
GC Srivastava

A pot experiment was conducted in the rabi (post rainy) seasons of 2001 and 2002 to study the genotypic differences in grain growth rate and endogenous hormonal content in the developing grains of hexaploid and tetraploid wheat. The endogenous hormonal contents of grains in both the ploidy levels had changed in sequence. At 5 days after anthesis (DAA), gibberellic acid (GA3); at 15 DAA (rapid growth phase), indole-acetic acid (IAA); at 25 DAA (dough stage), abscisic acid (ABA) were maximum. At 35 DAA, all the endogenous hormonal level decreased and among the hormones, ABA was highest followed by IAA and GA3. Hexaploids recorded higher concentrations of endogenous hormones (13.38% IAA, 17.89% GA3, and 14.7% ABA) on fresh weight basis and resulted in higher seed weight (56.99 mg/grain) and grain growth rate (0.009 g/g/day) compared to tetraploids (49.08 mg/grain; 0.008 g/g/day) on dry weight basis by better mobilization of photosynthates during grain filling. Key Words: Grain growth rate, hormones, indole-acetic acid, gibberellic acid, abscisic acid. doi:10.3329/bjar.v33i3.1608 Bangladesh J. Agril. Res. 33(3) : 493-502, September 2008


1994 ◽  
Vol 119 (3) ◽  
pp. 408-413 ◽  
Author(s):  
Anwar A. Khan

A gibberellic acid (GA) biosynthesis inhibitor, tetcyclacis, induced dormancy in nondormant seeds of lettuce (Lactuca sativa L.), tomato (Lycopersicon esculentum Mill.), pepper (Capsicum annuum L.), carrot [Daucus carota var. sativus (Hoffn.)], onion (Allium cepa L.), celery (Apium graveolens L.), and impatiens (Impatiens novette), as most of the seeds failed to germinate after washing under conditions that permitted germination before dormancy induction. In lettuce seeds, tetcyclacis and paclobutrazol were more effective in inhibiting germination in light than in darkness. A 16- to 24-h soak treatment with tetcyclacis was sufficient to induce dormancy in nearly all seeds. Tetcyclacis failed to induce dormancy if applied after 6 h presoak in water. Dormancy induced by tetcyclacis was released by GA4+7 (a mixture of gibberellin A4 and A7), light, and moist-chilling treatments. When GA4+7 was applied with tetcyclacis, dormancy induction was prevented under both favorable, e.g., 25C, and unfavorable, e.g., 5C, or low water potential (Ψ), germination conditions. Unlike tetcyclacis, abscisic acid (ABA) failed to induce dormancy in lettuce seeds. Thermodormancy induction in lettuce seeds at 35C was prevented by fluridone. However, neither ABA nor tetcyclacis countered its effect. Dormancy was also induced in lettuce seeds by ancymidol, flurprimidol, or paclobutrazol. Dormancy induced by tetcyclacis in pepper, tomato, carrot, and onion seeds was released by GA4+7, but not by irradiation or moist-chilling. Chemical names used: 5-(4-chlorophenyl)-3, 4, 5, 9, 10-pentaazatetracyclo [5.4.102,6.08,11]-dodeca-3, 9-diene (tetcyclacis); 1-(4-chlorophenyl)-4, 4-dimethyl-2-(1H-1, 2, 4-triazole-1-yl)-3-pentanol (paclobutrazol); α-cyclopropyl-α-(4-methoxyphenyl)-5-pyrimidine methanol (ancymidol); α-(1-methyl)-α-[4-(trifluoromethoxy) phenyl]-5-pyrimidine-methanol (flurprimidol); 1-methyl-3-phenyl-5-[3-(trifluoromethyl)phenyl]-4 (1H)-pyridinone (fluridone).


1969 ◽  
Vol 89 (3-4) ◽  
pp. 159-168
Author(s):  
Carlos A. Flores ◽  
Winston De la Torre ◽  
Miguel Monroig ◽  
Wigmar González

Applications of gibberellic acid (GA), paclobutrazol and gibberellic acid (Paclo/GA), fluoridone and gibberellic acid (FL/GA), and abscisic acid (ABA) were made to synchronize flowering in coffee trees (Coffea arabica L.). Overall growth of trees and branches was not affected by the treatments. Production of new leaves was not affected by the treatments. However, the Paclo/GA treatment tended to increase the production of secondary branches. Flower bud production was affected by the ABA treatment during the first three weeks, showing an initial reduction in number and a late development of buds. Plants receiving the GA treatment produced more flowers during the first week of evaluation as well as a higher number and greater weight of mature fruits during the first week of harvesting. 


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