Studies on the action of abscisic acid on IAA-induced rapid growth of Avena coleoptile segments

Planta ◽  
1973 ◽  
Vol 114 (1) ◽  
pp. 87-93 ◽  
Author(s):  
J. J. Philipson ◽  
J. R. Hillman ◽  
M. B. Wilkins
Keyword(s):  
Abscisic Acid ◽  
Rapid Growth ◽  
Avena Coleoptile

scholarly journals Rapid Growth Inhibition of Avena Coleoptile Segments by Abscisic Acid

1973 ◽  
Vol 51 (1) ◽  
pp. 93-96 ◽  
Author(s):  
Marilyn M. Rehm ◽  
Morris G. Cline
Keyword(s):  
Abscisic Acid ◽  
Growth Inhibition ◽  
Rapid Growth ◽  
Avena Coleoptile

Changes in the Concentrations of Abscisic Acid in Fruits of Normal and Nr, rin and nor Mutant Tomatoes During Growth, Maturation and Senescence

1976 ◽  
Vol 3 (6) ◽  
pp. 809 ◽  
Author(s):  
WB Mcglasson ◽  
I Adato
Keyword(s):  
Abscisic Acid ◽  
Rapid Growth ◽  
Ethylene Production ◽  
Maximum Level ◽  
Ethylene Evolution ◽  
Tissue Accumulation

The concentrations of free and base-hydrolysable (bound) abscisic acid (ABA) were measured in fruits of cv. Rutgers (normal) and of the mutants Nr, rin and nor during growth, maturation and senescence. Measurements were made also of postharvest changes in free ABA in immature Rutgers fruits. Free ABA began to accumulate rapidly in the pericarp of developing fruits of Rutgers, Nr and rin during the period of most rapid growth but accumulation in nor was delayed and slower. Peak concentrations in Rutgers, Nr and rin were similar but the maximum level in nor was about 50% lower. Peak concentrations of free ABA coincided with the completion of growth in Rutgers and rin but peak levels in Nr and nor were not reached until several days later. Colouring in all strains occurred at approximately the same time as the accumulation of peak concentrations of free ABA. Changes in bound ABA paralleled those in free ABA in pericarp tissue of all strains but the levels were about one-seventh of those of free ABA. Free and bound ABA were measured in seeds and associated mucilaginous tissue only in 50% developed and fully grown fruits. In the younger fruits of Rutgers, Nr and rin, this fraction contained a higher concentration of free ABA than the pericarp tissue. In fully grown fruits, the level of ABA in the seeds and associated tissue was much less than in this fraction of younger fruits and less than half that in the pericarp tissue. Free ABA in seeds and associated tissues remained low in nor fruits of both ages. The ratios of bound and free ABA in seeds and associated tissues in all strains were generally similar to those found in pericarp tissue. In Rutgers fruits, free ABA increased after harvest. It is suggested that ABA is produced in both pericarp and seeds plus associated mucilaginous tissue. Accumulation of ABA does not seem to be a result of increased ethylene production but conversely may be involved in the increased ethylene evolution which accompanies ripening in normal strains. Since the pattern of changes in ABA and the accumulation of peak concentrations in pericarp tissue was not consistently related to growth but was closely related to the onset of symptoms of ripening or senescence, ABA may be a regulator of ripening in the tomato.

Control of Fruit Ripening in Peach, Prunus persica: Action of Succinic Acid-2,2-Dimethylhydrazide and (2-Chloroethyl)Phosphonic Acid

1974 ◽  
Vol 1 (1) ◽  
pp. 77 ◽  
Author(s):  
NE Looney ◽  
WB Mcglasson ◽  
BG Coombe
Keyword(s):  
Abscisic Acid ◽  
Succinic Acid ◽  
Phosphonic Acid ◽  
Rapid Growth ◽  
Ethylene Production ◽  
Prunus Persica ◽  
Physiological Activity ◽  
Growth Period ◽  
Stage Ii ◽  
Stage Iii

Fruits of Halehaven and Fragar peaches (mid- and late season respectively) were sampled and examined weekly during one complete growing season. The period of rapid growth following anthesis (stage I) was characterized by relatively high respiration and ethylene production rates. Fruits of both cultivars entered the subsequent period of slow growth (stage II) together. Ethylene production was low and respiration declined throughout stage II. Sprays of (2-chloroethyl)phosphonic acid (ethephon), but not succinic acid-2,2-dimethylhydrazide (SADH), resulted in increased ethylene evolution by stage II fruits. Neither chemical altered respiration or the duration of stage II. Both chemicals, however, advanced commercial harvest and promoted ripening of fruits sampled throughout the final rapid growth period (stage III). All fruits sampled during stage III showed a climacteric-like increase in respiration and ethylene production. The horticultural effectiveness of SADH and ethephon appears to be due to a promotion of physiological activity in stage III. Abscisic acid in peach pericarp increased just before and during stage III. Possible roles for abscisic acid and ethylene in regulating the stage II-stage III transition in peaches and other fruits are discussed.

The effect of abscisic acid on the uptake of potassium and chloride into Avena coleoptile sections

Planta ◽  
1974 ◽  
Vol 116 (2) ◽  
pp. 173-185 ◽  
Author(s):  
Nu-may R. Reed ◽  
Bruce A. Bonner
Keyword(s):  
Abscisic Acid ◽  
Avena Coleoptile

Removing Substrate Background in TEM Microanalysis

1974 ◽  
Vol 32 ◽  
pp. 568-569
Author(s):  
John C. Russ ◽  
Nicholas C. Barbi
Keyword(s):  
Electrical Conductivity ◽  
Rapid Growth ◽  
Organic Film ◽  
Absolute Concentration ◽  
Background Signal ◽  
X Ray ◽  
Elemental Concentrations ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
The Continuum

The rapid growth of interest in attaching energy-dispersive x-ray analysis systems to transmission electron microscopes has centered largely on microanalysis of biological specimens. These are frequently either embedded in plastic or supported by an organic film, which is of great importance as regards stability under the beam since it provides thermal and electrical conductivity from the specimen to the grid.Unfortunately, the supporting medium also produces continuum x-radiation or Bremsstrahlung, which is added to the x-ray spectrum from the sample. It is not difficult to separate the characteristic peaks from the elements in the specimen from the total continuum background, but sometimes it is also necessary to separate the continuum due to the sample from that due to the support. For instance, it is possible to compute relative elemental concentrations in the sample, without standards, based on the relative net characteristic elemental intensities without regard to background; but to calculate absolute concentration, it is necessary to use the background signal itself as a measure of the total excited specimen mass.

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