Influence Of Gibberellic Acid Research Articles

The influence of gibberellic acid and abscisic acid on cell and tissue differentiation of bean callus.

Bean callus was induced to form roots (tissue differentiation) and vascular nodules (cell differentiation) by lowering the ratio of auxin to cytokinin in the growth medium. Both types of differentiation were inhibited by the addition of abscisic acid (at concentrations greater than I muM) to induction medium. Initiation of differentiation was inhibited, but its subsequent development was not, and the inhibition was not affected by the addition of gibberellic acid. Addition of gibberellic acid (GA) alone to induction medium stimulated tissue differentiation, although cell differentiation was unaffected (30 muM GA) or inhibited (45 muM GA) and its onset was delayed at both concentrations. Root initiation was also stimulated by gibberellic acid (0.I-45 muM) at an auxin-to-kinin ratio 10 times that normally optimal for cell differentiation. The phenylalanine ammonia lyase (PAL) activity of the calluses was closely correlated with the amount of cell differentiation which had occurred, and measurement of this confirmed that gibberellic acid delayed the initiation of cell differentiation. The increase and subsequent decline of PAL and betaI leads to 3 glucan synthetase activities, normally induced by transfer to induction medium, was abolished by abscisic acid. Addition of gibberellic acid did not affect the betaI leads to 3 glucan synthetase activity.

Effects of Gibberellic Acid, Calcium, Kinetic, and Ethylene on Growth and Cell Wall Composition of Pea Epicotyls

The influence of gibberellic acid (GA), calcium, kinetin, and ethylene on growth and cell-wall composition of decapitated pea epicotyls (Pisum sativum L. var. Alaska) was investigated. Calcium, kinetin, and ethylene each caused an inhibition of GA-induced elongation of pea stems. Gibberellic acid did not reverse the induction of swelling by Ca(2+), kinetin, or ethylene. Both Ca(2+) and ethylene significantly inhibited the stimulatory effects of GA on the formation of residual wall material. Although GA promoted the development of walls relatively low in pectic substances and pectic uronic acid, Ca(2+), kinetin, and ethylene favored the formation of walls rich in these constituents. Calcium, kinetin, and GA, alone or in combination, had no effect on the production of ethylene by pea epicotyls.

The influence of gibberellic acid on growth and metabolic products of Ammi visnaga L.

Gibberellic-Acid-treatments tended to increase the stem height, and decreased the umbel number. Seed yield per plant was not affected by different doses of GA. Moreover, GA which resulted in lower carbohydrate content, induced simultaneously more oil percent and total chromone formations in the seeds ofAmmi visnaga.

Consommation d'oxygène modifiée par l'acide gibbérellique, chez des tissus fragmentés de tubercules de Solanum tuberosum, en fonction de l'âge de ces organes

Influence of gibberellic acid on the oxygen uptake of fragmented tissues of tubers of S. tuberosum as a function of the age of these storage organs. Application of gibberellic acid at various concentrations has been repeated regularly to potato discs from the central part of the tubers in the course of the months following two consecutive harvests. Definite variations have been observed in the possibility to modify the oxygen uptake of these storage organs conserved in controlled conditions after harvest, such variations being related to the sprouting stage of the tubers.

Influence of Gibberellic Acid on Early Patch Budding of Pecan Seedlings1

Abstract A lanolin - potassium gibberellin (GA3) mixture when applied to the trunks of pecan seedlings, beginning 7-10 days after emergence and continuing at 10-14 day intervals for a total of 4 treatments, resulted in sufficient trunk growth for successful patch budding to be accomplished by the end of the third month of growth.

The Influence of Gibberellic Acid on the Permeability of Model Membrane Systems

Gibberellic acid increases the permeability of model membranes composed of various plant-source lipids, a sterol, and dicetyl phosphate. As a result of hormone treatment, the flux of uncharged molecules such as glucose or sucrose, or charged ions such as chromate, through the model membranes (liposomes or micelles) is increased. The revelance of this finding to the in vivo effects of the hormone is briefly discussed.

Influence of gibberellic acid and 2-chloroethyltrimethylammonium chloride (CCC) on estrogen content of beans

The influence of GA and CCC on endogenous estrogens content in beans was investigated. The experiments were conducted in two variants analysing the amounts of estrogens 12, 24, 48, 96 h after application, and in the specific stages of plant development. The lack of influence of GA and the lowering of estrogens content under the influence of CCC was observed.

Influence of gibberellic acid and nitrogen sprays on transmission of cabbage black ringspot virus by Myzus persicae (Sulz.)

Transmission of cabbage black ringspot virus to turnip plants by Myzus persicae (Sulz.) was reduced by foliar sprays of five parts per million gibberellic acid together with 0·2% ammonium nitrate, but not by each applied separately. The reduction occurred at 10°C but not 15, 20 or 25°C, and at a light intensity of 10 000 lux but not at 5 000 lux. The response was usually only evident towards the end of the normal range of the incubation periods, indicating that protection was probably only achieved when relatively small amounts of inoculum were introduced. The reduced transmission could not be related to aphid behaviour but changes were found in the free proline content and fine surface structure of treated leaves, and it is suggested that the results are to be interpreted in terms of changes in host cell metabolism.

Influence of Gibberellic Acid on Nucleolar Size Changes in Storage-tissue 3

Influence of Gibberellic Acid on Nucleolar Size Changes in Storage-tissue 3

A Translocatable Cold Hardiness Promoter

Hardy woody species which cold acclimate late or slowly are often injured by early autumn frosts. Adapted hardy species characteristically stop growing and acclimate to some extent prior to autumn frosts. In nature this first stage of acclimation appears to be induced by shortening photoperiods in a number of woody species (4, 23, 24). Because growth cessation is associated with cold acclimation in woody plants, a considerable amount of work has been done to determine whether growth retarding chemicals can induce cold acclimation in the absence of inductive photoperiods. The growth retardants tested have been found to have only slight and often inconsistent effects on hardiness (7, 8, 13, 15). Such findings have stimulated interest in elucidating the effective endogenous system(s) which induce acclimation in hardy species (7, 8). Several researchers have recently reported that short-day-induced leaves are the source of translocatable hardiness promoting factor(s) (4, 5, 10). The existence of such a factor(s) is of practical interest because it (they) may prove to be a relatively simple compound(s) which could be applied exogenously to induce acclimation in the absence of inductive environmental stimuli. There is, as yet, no evidence to indicate whether or not the promoting factor(s) is genotype specific. A considerable amount of research has been done on the environmental control of cold acclimation (1, 4, 10, 24), the natural patterns of acclimation (4, 22), and the metabolic changes associated with acclimation (14) in red-osier dogwood (Cornus stolonifera Michx.). In nature, acclimation usually proceeds in two distinct stages which appear to be induced by short days and low temperatures (4, 21, 22), respectively. Climatic races collected from various sites in North America were found to differ greatly in the timing and rate of cold acclimation when they were grown in a uniform environment field plot in Minnesota (18). In the field at St. Paul, Minnesota (45° North latitude), a clone from Dickinson, North Dakota (47° North latitude), was found to begin cold acclimating as much as 8 weeks earlier in the autumn than a clone from Seattle, Washington (47° North latitude) (20). Both races eventually acclimate to below -196 C, but the Seattle race is often injured severely by the first frost in the autumn at St. Paul. The influence of gibberellic acid and abscisic acid on cold acclimation has been studied in the hardy tree, Acer negundo (8). Based on these results, Irving has suggested that abscisic acid may be the hardiness promoting factor (6).

Influence of gibberellic acid on the incorporation of 8- 14C adenine into adenosine 3′,-5′-cyclic phosphate in barley aleurone layers

Influence of gibberellic acid on the incorporation of 8- 14C adenine into adenosine 3′,-5′-cyclic phosphate in barley aleurone layers

Effect of plant growth-promoting rhizobacteria and gibberellic acid on salt stress tolerance in tomato genotypes.

Salinity stress is a limiting factor that affects attainment of optimal yield of many vegetable crops at various growth stages in many arid and semi-arid parts of sub-Saharan Africa. The objective of this study was to explore salt tolerance of tomato (Solanum lycopersicum L.) genotypes under the influence of gibberellic acid (GA3) and Bacillus subtilis under screen house conditions. Tomato seeds were pre-soaked with 0, 0.4, 0.5 or 0.6 mM concentrations of GA3 and control in distilled water, respectively; for 12 hr at room temperature. The seeds were germinated in a screen house in 10 kg of soil contained 0, 100, or 200 mM NaCl treatment in polyethene bags. After two weeks of seed germination, the seedlings were inoculated with B. subtilis with the exception of controls. Results revealed that the single or combined treatments of GA3 (at different concentrations) and Bacillus subtilis significantly (P<0.05) increased photosynthetic pigments, and enhanced the concentrations of potassium, calcium, magnesium and phosphorus ions in the salt-stressed tomato. Both tomato genotypes showed low concentrations of sodium ions at all levels of gibberellic acid with Bacillus subtilis. Also, there were significant (P < 0.05) increases in the compatible solutes, antioxidant enzymes activity and antioxidant potential of salt-stressed tomato genotypes, in the combined treatments of GA3 and Bacillus subtilis. Tomato genotypes treated with GA3 and Bacillus subtilis, showed greater salt-tolerance even at high levels of salinity, than single treatment of either GA3 or Bacillus subtilis. Based on these findings, the genotypes are suitable for future breeding programmes to achieve optimal crop yield in saline conditions.

The effect of gibberellic acid on Hansenula wingei.

The present study shows the influence of gibberellic acid on the budding and cell division of three strains of Hansenula wingei. Gibberellic acid at 10 μg/ml increased cell division of all the strains of H. wingei tested. The rate of budding and cell division diminished as the concentration of gibberellic acid increased over or decreased below 10 μg/ml. Also tested was the ability of gibberellic acid at a concentration of 10 μg/ml to stimulate the synthesis of deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and protein contents of both haploid and diploid strains of H. wingei. The rate of DNA, RNA, and protein synthesis decreased as the concentration of gibberellic acid was increased over or decreased below 10 μg/ml.

Effect of Gibberellic Acid on the Elongation Rate of Agrostis alba Root Hairs

AbstractThe influence of gibberellic acid over a wide range of concentrations on the rate of elongation of root hairs of redtop grass was investigated. The rate of root hair elongation was increased by GA over the concentration range of 10−7 to 10−12 M inclusive, with peak stimulation occurring at 10−6 M. Although root hair growth was slightly accelerated by 10−6 M GA, this concentration damaged many root hairs and caused some to stop growing altogether. Rate of root hair elongation was reduced to less than 84% of the control by 10−5 M GA.

Comparative influence of gibberellic acid and of plant population on distribution of potato tuber size

The comparative influence of GA and of plant population on distribution of tuber size was evaluated for 3 years. Both closer seed spacing and treating seed with GA resulted in a reduction in tuber size without marked changes in total yield. However, with a growing season of 97 days, yield of U. S. No. 1 tubers from GA-treated seed was lower than from nontreated seed. Cost of seed required to achieve a denser plant population compared to cost of treating seed with GA was approximately $69 versus $1 per acre.

Influence of gibberellic acid on nucleic acid synthesis in dwarf pea internodes

Influence of gibberellic acid on nucleic acid synthesis in dwarf pea internodes

Influence of Gibberellic Acid and Gibrel on Fruit Set and Yield in Vaccinium macro‐carpon cv. Early Black

AbstractThe influence of gibberellic acid (GA) and Gibrel on the parthenocarpic development of cranberries (Vaccinium macrocarpon cv. Early Black) was investigated. Application of GA or Gibrel at 25 % bloom, 50 % bloom, 100 % bloom and after bloom resulted in a much higher than normal percentage fruit set and large increases in yield. However, treatment of cranberry vines with these compounds also resulted in an abundance of small, commercially undesirable berries. In addition, application of GA caused abnormal elongation of the vines and inthibited terminal bud development. Gibrel caused only slight vine elongation and did not retard terminal bud development. The possible use of Gibrel in the commercial production of cranberries is discussed.

A preliminary study on the influence of gibberellic acid onMentha arvensis Linn. var.piperascens holmes (Japanese mint)

“Gibberellic acid (GA3) solutions (10–200 p.p.m.) when sprayed onMentha arvensis Linn. var.piperascens at preflowering stage induces 30–50 per cent. increase in the yield of total herb. Apart from the elongation of internode, the leaf area was also increased. The stage of development of the plant at the time of treatment, appeared to be a significant factor in obtaining favourable Gibberellin effects. Pre-soaking of the suckers in GA solution induced early sprouting. Essential oil obtained from the treated leaves, however, decreased by 5–15 per cent. but had no deleterious effect on menthol contents.”Mentha arvensis Linn. var.piperascens (Japanese mint) which has been introduced in India by the Regional Research Laboratory, Jammu, is now fairly well established for commercial exploitation of natural Menthol. During the course of investigation on the influence of Gibberellic Acid (GA) on various aromatic plants, the authors studied its effect on the growth, volatile oil and Menthol contents of this mint.

Effects of Gibberellic Acid on the Fixed Oils of Four Plants

The influence of gibberellic acid on the quality of fixed oils from four plants has been studied. Sesame, castor bean, sunflower, and flax plants were treated with aqueous solutions of gibberellic acid when the plants reached blooming size and at 2-week intervals until harvest. The iodine values and the quantity of unsaponifiable matter varied between samples and between oils from different species of plants. Significant variations from normal were produced in castor and sesame oils. The differences consisted of higher saponification values in both oils and a lower acid value in the latter. A higher saponification value indicating shorter chain fatty acids was the only characteristic common to all oils from treated plants. Some of the changes obtained were from plants that had insignificant or no visible morphological differences. The influence of gibberellic acid on the quality of fixed oils from four plants has been studied. Sesame, castor bean, sunflower, and flax plants were treated with aqueous solutions of gibberellic acid when the plants reached blooming size and at 2-week intervals until harvest. The iodine values and the quantity of unsaponifiable matter varied between samples and between oils from different species of plants. Significant variations from normal were produced in castor and sesame oils. The differences consisted of higher saponification values in both oils and a lower acid value in the latter. A higher saponification value indicating shorter chain fatty acids was the only characteristic common to all oils from treated plants. Some of the changes obtained were from plants that had insignificant or no visible morphological differences.

Comparative Study of the effects of applied indoleacetic acid and horizontal orientation of the primary shoot, upon internode extension and petiole orientation inHelianthus Annuus, and the modifying influence of gibberellic acid

1. It is shown that subjecting potted sunflower plants to alternating periods of horizontal and erect orientation, with or without occasional rotation of the primary axis, results in a marked reduction in the rate of stem extension growth, the development of petiole epinasty and increased downward orientation of the leaves. Neither of these symptoms appears to be a direct gravitational response to the horizontal position. 2. It is demonstrated that the petiole epinasty is probably a correlative phenomenon while the inhibition of extension growth apparently results from the development of a factor which takes 24–48 hours to reach maximum intensity after the application of the horizontal stimulus. 3. Similar responses can be induced in permanently erect plants by applying IAA in amounts greater than about 5 μg/plant. 4. The application of GA to either horizontally stimulated or IAA treated plants, alleviates both the petiole epinasty and the inhibition of extension growth. 5. The results obtained are in agreement with the hypothesis that placing the shoot in the horizontal position causes an increase in the concentration of stem auxin and that this induces petiole epinasty and brings about a reduction in stem extension growth. In view of the alleviating influence of GA, it is suggested that the postulated increase in stem auxin may effect extension growth by reducing the natural gibberellin level in the stem to suboptimal values.