The effects of 3-indoleacetic acid, gibberellic acid and vitamin E on flower initiation in unvernalised Petkus winter rye plants

1963 ◽  
Vol 50 (14) ◽  
pp. 505-505 ◽  
Author(s):  
J. Bruinsma ◽  
S. S. Patil
2021 ◽  
Vol 4 (11(75)) ◽  
pp. 11-16
Author(s):  
А. Kurylenko ◽  
O. Kurylenko ◽  
О. Kuchmenko ◽  
V. Havii

Purpose. The aim of the study is to investigate the effect of pre-sowing treatment of winter rye seeds of Synthetic 38 and Zabava with compositions of metabolically active substances on the content of photosynthetic pigments in plant leaves at different phases of ontogenesis. Materials and methods. The research materials were winter rye varieties Synthetic 38 and Zabava, and combinations of metabolically active substances: vitamin E (10-8M), paraoxybenzoic acid (0,001%), methionine (0,001%), ubiquinone-10 (10-8M) and MgSO4 (0,001%). The research scheme provided 4 options: 1) control (untreated seeds); 2) seeds, treated with a composition of substances: vitamin E + paraoxybenzoic acid + methionine + MgSO4; 3) seeds treated with a composition of substances: vitamin E + paraoxybenzoic acid + methionine; 4) seeds, processing by composition of substances: vitamin E + ubiquinone-10. Studies were conducted in the following phases of rye development: tillering, tubing, earing, flowering. The content of pigments - chlorophyll a, b and the total content of chlorophyll in the leaves of rye plants was determined by spectrophotometric method. Results and conclusions. It was demonstrated for the first time that the use of compositions of metabolically active compounds for pre-sowing treatment of winter rye varieties Synthetic 38 and Zabava leads to an increase of main chlorophyll, chlorophyll a and b in plant leaves in the dynamics from tillering to flowering. The composition consisting of vitamin E, para-oxybenzoic acid, methionine and MgSO4 showed the greatest efficiency. The effectiveness of this composition may be due to the complex action of all metabolically active compounds that are part of it. The obtained results may indicate a potentially more efficient absorption and conversion of energy by plants and the positive effect of these compositions on the photosynthesis of winter rye plants. Substances that have shown their effectiveness can be used as components of stimulants.


1977 ◽  
Vol 4 (4) ◽  
pp. 479 ◽  
Author(s):  
JB Reid ◽  
PJ Dalton ◽  
IC Murfet

Gibberellic acid is shown to cause a substantial delay in the flowering node, time of flower initiation and leaf requirement for flowering in the late pea cultivar line 24, grown under an 8-h photoperiod. In continuous light, gibberellic acid caused only a small delay in the flowering node and leaf require- ment. As the plants became older the effect of applied gibberellic acid decreased. This was not due to initiation having already occurred or to the gibberellic acid not penetrating the plant. It is suggested that gibberellic acid has a direct effect on the flowering process in line 24 plants grown under an 8-h photoperiod and that it may act by reducing the effect of age on the gene Sn.


1977 ◽  
Vol 32 (9-10) ◽  
pp. 798-802 ◽  
Author(s):  
Claus Buschmann ◽  
Hartmut K. Lichtenthaler

Abstract The Hill-activity (reduction of DCPIP or methylviologen) and the concentration of P700 were studied in chloroplasts isolated from cotyledons of radish seedlings (R aphanus sativu s L. Saxa Treib), which had been grown with the addition of β-indoleacetic acid (IAA), kinetin, or gibberellic acid.1) The photosynthetic activity of young chloroplasts from 3 day old Raphanus seedlings is very high (c. 180 μmol O2/mol chlorophyll × h) and decreases continuously thereafter with increasing age. The steady state Hill-activity is readied after 8 to 10 days (values of 55 to 50 μmol 02/mg chlorophyll × h).2) Chloroplasts from plants treated with IAA or kinetin not only exhibit higher plastoquinone levels 1,2, but also a higher P700-content and a higher Hill-activity. The promotion effect is more pronounced with kinetin (+ 36 to 40%) than with IAA (+ 12 to 17%).3) Gibberellic acid has a different effect on composition and activity of chloroplasts. In younger seedlings the Hill-activity appears to be somewhat stimulated, without promotion effect on plasto­ quinone 2 or P700 concentration. After 10 days GA3-treated plants show signs of chlorosis combined with a strong decrease in photosynthetic activity.4) The data clearly demonstrate that the composition and activity of the photosynthetic ap­ paratus are under phytohormone control. IAA and even better kinetin promote the light induced formation of pigment systems and electrontransport chains. GA3 seems to block the rebuilding of the photosynthetic apparatus under steady state conditions.


1970 ◽  
Vol 48 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Edgar Wagner ◽  
Bruce G. Cumming

In Chenopodium rubrum seedlings (ecotypes 50°10′ N and 49°58′ N) betacyanin synthesis is light dependent (completely dark-grown seedlings contain no betacyanin) and is under phytochrome control via both the low energy and the high-energy (HER) reactions of photomorphogenesis. In continuous light, accumulation of betacyanin is linear with time. However, when a single dark period interrupts continuous light, the amount of both betacyanin and chlorophyll synthesized during a given period of time after the dark interruption shows a rhythm reflecting differences in the rate of, and (or) the capacity for, pigment accumulation that are dependent on the duration of the dark period. The rhythm in chlorophyll content was higher in frequency than circadian, with a period of about 15 h, while rhythmicity in the rate of synthesis of betacyanin was circadian. These results suggest that there is endogenous rhythmicity in the metabolic state of the system in darkness. The imposition of light after darkness apparently stabilizes the specific physiological status attained at that respective time of darkness and thus determines the metabolic activity of the seedlings.When glucose was supplied throughout darkness interrupting continuous light, the phasing of the rhythm of betacyanin synthesis was positively correlated with the rhythm of flower initiation, but this was not so when phenylalanine was supplied during darkness. In contrast, when glucose was supplied for a varied length of time in continuous light, there was rhythmicity in the rate of betacyanin accumulation, with a periodicity of about 15 h, that was dependent on the duration of the glucose application.When seedlings were supplied with 10−6 M gibberellic acid during darkness there was a rhythm in the amount of hypocotyl elongation that depended on the length of a single dark period interrupting continuous light. Other evidence has suggested that there is a rhythm in the stability of the cellular membranes; this rhythm was assayed (non-physiologically) by the time of onset of betacyanin leakage from seedlings into an extraction medium and was apparent only after application of 10−10 M gibberellic acid. The rhythms in hypocotyl elongation and in membrane stability that were revealed after the application of gibberellic acid suggest that there may be a rhythm in the rate of differentiation and (or) development of the system.It is postulated that endogenous rhythmicity is due to the spatial separation of energy production and use in different cell particulates, with phytochrome acting as a membrane operator.


1971 ◽  
Vol 49 (5) ◽  
pp. 687-693 ◽  
Author(s):  
T. T. Lee

Indoleacetic acid (IAA) oxidase in tobacco callus tissues (Nicotiana tabacum L., cultivar White Gold) grown on a medium supplemented with gibberellic acid (GA3), IAA, and kinetin was resolved into seven isoenzymes by polyacrylamide gel electrophoresis. Gibberellic acid promoted the development of three fast-migrating IAA oxidase isoenzymes which were 7- to 10-fold more active than those of the control. Gibberellic acid was effective at 2 × 10−9 M and its activity increased with increasing concentration up to 2 × 10−7 M. Actinomycin D and cycloheximide inhibited the development of these isoenzymes, suggesting a requirement for both RNA and protein synthesis. The GA3-promoted IAA oxidase isoenzymes increased with time and were positively associated with the GA3-induced characteristic type of growth.The expression of the GA3 effect on IAA oxidase isoenzymes and growth was dependent on IAA and kinetin. In the presence of appropriate concentrations of kinetin, the combined effect of GA3 and IAA was more than additive. A possible interpretation of the GA3–IAA interaction is discussed.


Weed Science ◽  
1973 ◽  
Vol 21 (1) ◽  
pp. 19-23 ◽  
Author(s):  
Chris K. H. Teo ◽  
Leo E. Bendixen ◽  
Roy K. Nishimoto

Varying concentrations of benzyladenine (BA), indoleacetic acid (IAA), gibberellic acid (GA), abscisic acid (ABA), and 2-chloroethylphosphonic acid (ethephon) were used to induce sprouting of dormant purple nutsedge (Cyperus rotundusL.) tubers. BA at 50 to 300 ppm stimulated sprouting. The continuous presence of BA during the sprouting period was necessary to give significant sprout stimulation. Neither IAA at 1, 10, or 100 ppm; GA at 10, 100, or 1000 ppm; nor ethephon at 10, 100, or 1000 ppm had stimulatory effects on sprouting. ABA counteracted the stimulatory effects of BA when tubers were treated with ABA following BA treatment. Sprouting was markedly greater at 33 C day, 25 C night than at 24 C day, 17 C night. Growth of plants originating from tubers pretreated with 100 ppm BA did not differ significantly from the controls. Sustained BA applications at 100 and 200 ppm produced numerous plants with tuft-type growth habit, delayed flowering, and reduced the number of inflorescences. Numerous short, diageotropic rhizomes were produced.


1958 ◽  
Vol 119 (3) ◽  
pp. 197-200 ◽  
Author(s):  
T. H. Plummer ◽  
M. L. Tomes

1990 ◽  
Vol 68 (5) ◽  
pp. 965-978 ◽  
Author(s):  
Deborah D. Shushu ◽  
Elizabeth G. Cutter

It was previously shown that removal of the ovary, which occupies the distal millimetre, caused cessation of growth of the gynophore and its intercalary meristem, suggesting that the ovary was a source of growth-promoting substances. Control of growth was studied in the gynophore of the peanut Arachis hypogaea L., cv. Bukene No. 2. Low concentrations of indoleacetic acid promoted growth of decapitated gynophores, whereas high levels inhibited elongation. Gibberellic acid promoted growth of the decapitated gynophores, whereas kinetin inhibited growth at all concentrations used. A combination of indoleacetic acid and gibberellic acid promoted extension growth of the decapitated gynophores above that of the intact gynophores; this was characterized, however, by a different pattern of cell division and cell elongation from that observed in the intact gynophores. Indoleacetic acid affected the "youngest" tissues, whereas gibberellic acid affected the whole length of the growing zone. High levels of indoleacetic acid caused diageotropism of the gynophores. Application of [14C] indoleacetic acid to vertical gynophores after the ovary was excised indicated that indoleacetic acid became redistributed to one side, resulting in horizontal bending. Thus an increased amount of auxin from the enlarging ovary may be involved in placing the ovary parallel to the soil surface when it reaches a suitable depth in the soil, during normal geocarpic development. Triiodobenzoic acid reduced growth when applied in lanolin as a ring between the ovary and the meristem but not when applied proximal to the meristem, suggesting that triiodobenzoic acid prevented the transport of auxin from the ovary to the meristem.


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