Apical dominance and the levels of indole acetic acid in Phaseolus lateral buds

Planta ◽  
1977 ◽  
Vol 134 (2) ◽  
pp. 191-193 ◽  
Author(s):  
J. R. Hillman ◽  
V. B. Math ◽  
G. C. Medlow
1970 ◽  
Vol 48 (11) ◽  
pp. 1989-1994 ◽  
Author(s):  
A. Ali ◽  
R. A. Fletcher

Hormonal regulation of apical dominance in soybeans is dependent on the physiological stage of the lateral buds. In 7-day-old plants the cotyledonary buds are in an active state of mitosis and the application of a single hormone, gibberellic acid (GA) is effective in releasing the buds whilst indole acetic acid (IAA) is ineffective in inhibiting the buds of decapitated plants. In 16-day-old plants in which mitosis in the cotyledonary buds had ceased, a combination of both benzyladenine (BA) and GA was required for bud growth. BA initiated mitosis and GA promoted elongation. Application of IAA to the apical cut surface of these plants was effective in maintaining the inhibition of cotyledonary buds, and this inhibition could be overcome by a direct application of BA and GA to the inhibited buds. This study has shown that the growth of the inhibited cotyledonary buds in soybeans is regulated not only by auxins but by an interaction between auxins, cytokinins, and gibberellins. The effectiveness of any one of these hormones in inhibiting or promoting growth of the buds is dependent on the age of the plant.


HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 541h-542
Author(s):  
Shiow Y. Wang ◽  
Miklos Faust ◽  
Michael J. Line

The effect of Indole-3-acetic acid (IAA) on apical dominance in apple (Malus domestica Borkh.) buds was examined by studying changes In proton density (free water) and membrane lipid composition in lateral buds. Decapitation induced budbreak and enhanced lateral bud growth. IAA replaced apical control of lateral bud paradormancy. Maximal inhibition was obtained when IAA was applied immediately after the apical bud was removed. Delaying this application weakens the effect of IAA. An increase in proton density in lateral buds was observable 2 days after decapitation, whereas the change in membrane lipid composition occurred 4 days later. Decapitating the terminal bud induced an increase in membrane galacto- and phospholipids. and the ratio of unsaturated to corresponding saturated fatty acids. Decapitation also induced a decrease in the ratio of free sterols to phospholipids in lateral buds. Application of IAA to the terminal end of decapitated shoots inhibited the increase of proton density and prevented changes in the membrane lipid composition of lateral buds.


2016 ◽  
Vol 5 (12) ◽  
pp. 5179
Author(s):  
Ilahi Shaik* ◽  
P. Janakiram ◽  
Sujatha L. ◽  
Sushma Chandra

Indole acetic acid is a natural phytohormone which influence the root and shoot growth of the plants. Six (GM1-GM6) endosymbiotic bacteria are isolated from Gracilaria corticata and screened for the production of IAA out of six, three bacterial strains GM3, GM5 and GM6 produced significant amount of IAA 102.4 µg/ml 89.40 µg/ml 109.43 µg/ml respectively. Presence of IAA in culture filtrate of the above strains is further analyzed and confirmed by TLC. As these bacterial strains, able to tolerate the high salinity these can be effectively used as PGR to increase the crop yield in saline soils.


Soil Systems ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 26
Author(s):  
Rihab Djebaili ◽  
Marika Pellegrini ◽  
Massimiliano Rossi ◽  
Cinzia Forni ◽  
Maria Smati ◽  
...  

This study aimed to characterize the halotolerant capability, in vitro, of selected actinomycetes strains and to evaluate their competence in promoting halo stress tolerance in durum wheat in a greenhouse experiment. Fourteen isolates were tested for phosphate solubilization, indole acetic acid, hydrocyanic acid, and ammonia production under different salt concentrations (i.e., 0, 0.25, 0.5, 0.75, 1, 1.25, and 1.5 M NaCl). The presence of 1-aminocyclopropane-1-carboxylate deaminase activity was also investigated. Salinity tolerance was evaluated in durum wheat through plant growth and development parameters: shoot and root length, dry and ash-free dry weight, and the total chlorophyll content, as well as proline accumulation. In vitro assays have shown that the strains can solubilize inorganic phosphate and produce indole acetic acid, hydrocyanic acid, and ammonia under different salt concentrations. Most of the strains (86%) had 1-aminocyclopropane-1-carboxylate deaminase activity, with significant amounts of α-ketobutyric acid. In the greenhouse experiment, inoculation with actinomycetes strains improved the morpho-biochemical parameters of durum wheat plants, which also recorded significantly higher content of chlorophylls and proline than those uninoculated, both under normal and stressed conditions. Our results suggest that inoculation of halotolerant actinomycetes can mitigate the negative effects of salt stress and allow normal growth and development of durum wheat plants.


1974 ◽  
Vol 29 (1-2) ◽  
pp. 39-41 ◽  
Author(s):  
H. Veen

Abstract Studies in vitro on the binding of phospholipids with IAA, α-NAA and some of their biologically inactive analogues demonstrate that the observed interaction between IA A and lecithin is not related to the primary action of the hormone in plant growth.


1980 ◽  
Vol 7 (6) ◽  
pp. 635 ◽  
Author(s):  
WR Scowcroft ◽  
PJ Larkin

Mesophyll protoplasts of two genetically distinct genotypes of N. debneyi were cultured with sustained division following a plating efficiency in excess of 50%. Fully fertile mature plants were regenerated from callus cultures derived from protoplasts. Shoots were induced in medium containing 1 mg/l 6-benzylaminopurine and 0.5 mg/I indole acetic acid. The repeatably high efficiency of protoplast culture was used to evaluate the quantitative effects of two drugs, kanamycin and trimethoprim, which effectively inhibited colony formation at concentrations of 100 and 50 �g/ml, respectively. An enhancer of DNA uptake, poly-L-ornithine, had virtually no effect on sustained protoplast division at a concentration of 7.5 �g/ml or less.


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