Biotransformation of Homofolate from a Growth Inhibitor to a Growth-Promoting Derivative

Chemotherapy ◽  
1983 ◽  
Vol 29 (6) ◽  
pp. 436-441 ◽  
Author(s):  
Nathan Grossowicz ◽  
Samuel Waxman
Keyword(s):  
Growth Inhibitor ◽  
Growth Promoting

Changes in the Endogenous Level of Auxins and Gibberellin-Like Substances in the Shoot Apices of Nitrogen-Deficient Tomato Plants (Lycopersicon esculentum Mill)

1974 ◽  
Vol 22 (3) ◽  
pp. 429 ◽  
Author(s):  
V Rajagopal ◽  
IM Rao
Keyword(s):  
Growth Inhibitor ◽  
Shoot Apices ◽  
Tomato Plants ◽  
Nitrogen Levels ◽  
Inhibitor Level ◽  
Gibberellin Activity ◽  
Three Stages ◽  
Last Stage ◽  
Growth Promoting ◽  
Normal Supply

Tomato plants were grown at three nitrogen levels: normal supply (control), moderate deficiency (one-eighth the normal supply – 1/8N) and acute deficiency (-N). Plant heights were reduced by 51.4 and 75.7 % respectively at 40 days under the latter two treatments compared with control plants. The biological activity of growth-promoting and growth-inhibiting substances was determined in the shoot apices of the three sets of plants at three stages: 20, 30 and 40 days after sowing. In general, the endogenous auxin was higher in control than in 1/8N and - N plants. The growth inhibitor level was higher in -N plants than in control and 118N plants. Gibberellin activity was less in nitrogen- starved plants than in controls. - N plants exhibited not only loss of gibberellins but an accumulation of inhibitors at the last stage. A negative correlation between growth promotors (auxins and gibberellins) and growth inhibitors was evident. The interaction between auxins, gibberellins and inhibitors is discussed.

Growth of kidney epithelial cells in culture: evidence for autocrine control

1984 ◽  
Vol 246 (3) ◽  
pp. C351-C354 ◽  
Author(s):  
L. J. Mordan ◽  
F. G. Toback
Keyword(s):  
Epithelial Cells ◽  
Conditioned Medium ◽  
Growth Inhibitor ◽  
Renal Epithelial Cells ◽  
Control Value ◽  
Cells In Culture ◽  
Autocrine Control ◽  
Growth Promoting ◽  
K Concentration ◽  
Low K

The factors that stimulate kidney growth in K+-deficient animals are unknown. Cultures of renal epithelial cells (BSC-1 line) were used to study this phenomenon because their growth is accelerated in medium containing a reduced K+ concentration. We tested the hypothesis that growth induced by low-K+ medium is mediated by factors produced by the cells; i.e., is subject to autocrine control. Low-K+ (3.2 mM) or control (5.4 mM) medium was conditioned by placing it on confluent cultures of BSC-1 cells for 1 h and was then collected. The K+ concentration of the low-K+ conditioned medium was then adjusted to the control value by addition of KCl. This conditioned medium stimulated growth of fresh cultures of cells to the same extent as did unconditioned low-K+ medium. The appearance of growth-promoting activity was maximal at a K+ concentration of 3.2 mM during conditioning of the medium. Low-K+ conditioned medium, corrected to a K+ concentration of 5.4 mM, required 6 h to commit cells to enhanced proliferation. Growth-stimulating activity in low-K+ conditioned medium was antagonized by a purified growth inhibitor produced by the cells. These observations are consistent with the hypothesis that autocrine products with opposite effects on growth can regulate proliferation of renal epithelial cells.

Physiological studies on dormancy in seeds of groundnut (Arachis hypogaea L.). III. Changes in auxin and growth inhibitor contents during development of the seeds of a dormant and a non-dormant cultivar

1971 ◽  
Vol 19 (3) ◽  
pp. 273 ◽  
Author(s):  
N Sreeramulu ◽  
IM Rao
Keyword(s):  
Arachis Hypogaea ◽  
Growth Inhibitor ◽  
Neutral Fraction ◽  
Growth Substances ◽  
Arachis Hypogaea L ◽  
Acidic Fraction ◽  
Rf Values ◽  
Bioassay Technique ◽  
Growth Promoting ◽  
Rice Coleoptile

Growth substances in developing seeds of dormant and non-dormant cultivars of groundnut were chromatographically separated, and their content at various RF values estimated by the rice coleoptile bioassay technique. Growth promotors increased from 20 to 30 days in the acidic and neutral fractions of the dormant and non-dormant seeds. From 30 days onwards, growth promotors decreased while inhibitors accumulated, but their relative proportions varied in the two types of seeds. In mature non-dormant seeds, the content of growth promotors in the acidic fraction was higher than that of inhibitors; in dormant seeds it was lower. In the neutral fraction the content of inhibitors was higher than that of promotors in seeds of both types. The balance of growth-promoting and inhibiting substances in relation to seed development and dormancy is discussed, and it is concluded that the acidic inhibitors are responsible for dormancy in groundnut seeds.

EFFECTS OF KINETIN AND BENZIMIDAZOLE ON THE GROWTH OF ETIOLATED PEA STEMS AND BARLEY COLEOPTILES

1960 ◽  
Vol 38 (6) ◽  
pp. 875-881 ◽  
Author(s):  
F. R. Forsyth ◽  
D. J. Samborski
Keyword(s):  
Cobalt Chloride ◽  
Indoleacetic Acid ◽  
Growth Inhibitor ◽  
Test Solution ◽  
Hot Water ◽  
Dichlorophenoxyacetic Acid ◽  
Optimum Growth ◽  
Final Length ◽  
Growth Promoting ◽  
2,4 Dichlorophenoxyacetic Acid

Optimum growth of etiolated pea stem sections was obtained in a basal solution of 3-indoleacetic acid, cobalt chloride, and sucrose. The final length of pea stem sections was increased when sucrose was added 2, 4, or 6 hours after 3-indoleacetic acid and cobalt were added to the test solution. Benzimidazole at 100 to 200 p.p.m. and kinetin at 1 p.p.m. added to the basal solution inhibited growth of etiolated pea stem sections. Growth.of the pea stem sections was inhibited when they were treated for 4 hours with kinetin plus 3-indoleacetic acid, then transferred to the basal solution for 14 hours. There was no growth inhibition when pea stem sections were treated for 4 hours with kinetin alone, followed by 14 hours on the basal solution. Similar results with kinetin were obtained when barley coleoptiles were used and 2,4-dichlorophenoxyacetic acid was the growth-promoting substance. Ether and hot water extracts of pea stem tissue pretreated with kinetin and 3-indoleacetic acid did not appear to contain a growth inhibitor.

Interaction of gibberellic acid, abscisic acid, and phenolic compounds in the control of hypocotyl growth of Amaranthus caudatus seedlings

1984 ◽  
Vol 62 (10) ◽  
pp. 2047-2052 ◽  
Author(s):  
S. D. Ray ◽  
M. M. Laloraya
Keyword(s):  
Abscisic Acid ◽  
Phenolic Compounds ◽  
Gibberellic Acid ◽  
Growth Inhibitor ◽  
Inhibitory Effect ◽  
Hypocotyl Growth ◽  
Amaranthus Caudatus ◽  
Combined Application ◽  
Growth Promoting ◽  
Potent Growth

Abscisic acid, a potent growth inhibitor, inhibits hypocotyl growth of Amaranthus caudatus (L.) seedlings. Phenolic compounds when applied with ABA (abscisic acid), antagonize ABA action and restore normal seeding growth. GA (gibberellic acid) promotes hypocotyl growth and on combined application with ABA, the ratio of their concentrations determines the course of the resultant growth. This interaction can be modulated by phenolic compounds. Phenolic compounds in low concentrations when present together with GA and ABA favour GA-induced growth by antagonizing the inhibitory effect of ABA. Inhibitory action of abscisic acid on growth is so far known to be counteracted only by growth-promoting hormones. Antagonistic action of phenolic compounds imparts a dual role to this class of compounds, balancing the effect of growth-promoting and growth-inhibiting hormones.

Xyloglucan- and cello-oligosaccharides: Antagonists of the growth-promoting effect of H+

1990 ◽  
Vol 80 (1) ◽  
pp. 109-113 ◽  
Author(s):  
Ester P. Lorences ◽  
Gordon J. McDougall ◽  
Stephen C. Fry
Keyword(s):  
Promoting Effect ◽  
Growth Promoting

Growth-promoting supervision: Reflections from women of color psychology trainees.

2019 ◽  
Vol 13 (3) ◽  
pp. 167-173
Author(s):  
Fiona C. Thomas ◽  
Jhodi-Ann Bowie ◽  
Lincoln Hill ◽  
Joelle T. Taknint
Keyword(s):  
Women Of Color ◽  
Psychology Trainees ◽  
Growth Promoting ◽  
Color Psychology
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