Activity of gibberellin-like substanices in the acidic butanol fraction of immature (9 mm) and mature green (16 mm) seeds of cv. Bountiful as measured on Progress No. 9 pea plants grown under red light. Each of 10 plants received extract equivalent to 0.5 g of seed. Shaded portions show activity above the confidence limits of the control. GA1 markers show the position to which authentic GA1 traveled in co-chromatography. T refers to toxicity.
Activities of separated and chromatographed substances in the nonacidic, acidic ethyl acetate and acidic butanol fractions from bean seeds, Phaseolus vulgaris L., cv. Bountiful and Kentucky Wonder, were measured in the Progress No. 9 dwarf pea bioassay grown under red light. Activity in the nonacidic fraction was shown to be attributable only to ne...
... The high levels of GAs in immature seeds generally decreased during seed maturation (McComb, 1961;Murakami, 1961;Skene and Carr, 1961;Corcoran and Phinney, 1962;Ogawa, 1963;Hashimoto and Rappaport, 1966;Rudrapal et al., 1992), which suggests that GAs in immature seeds play a primary role early in the process of seed development. The content of endogenous GAs dropped in shoots of lh-2 mutant of pea, in which GA biosynthesis is blocked, resulting in a dwarf phenotype compared with wild-type plants (Swain et al., 1993). ...
Gibberellins (GAs) in developing seeds of morning glory (Pharbitis nil) were quantified and localized by immunostaining. The starch grains began to be digested after the GA contents had increased and reached a plateau. Immunohistochemical staining with the antigibberellin A(1)-methyl ester-antiserum, which has high affinity to biologically active GAs, showed that GA(1) and/or GA(3) were localized around starch grains in the integument of developing young seeds, suggesting the participation of GA-inducible alpha-amylase in this digestion. We isolated an alpha-amylase cDNA (PnAmy1) that was expressed in the immature seeds, and using an antibody raised against recombinant protein, it was shown that PnAmy1 was expressed in the immature seeds. GA responsiveness of PnAmy1 was shown by treating the young fruits 9 d after anthesis with GA(3). RNA-blot and immunoblot analyses showed that PnAmy1 emerged soon after the rapid increase of GA(1/3). An immunohistochemical analysis of PnAmy1 showed that it, like the seed GA(1/3), was also localized around starch grains in the integument of developing young seeds. The localization of GA(1/3) in the integument coincident with the expression of PnAmy1 suggests that both function as part of a process to release sugars for translocation or for the further development of the seeds.
... Little is known of the endogenous concentration of gibberellins in mature banana tissue although some work has been done with bananas at an early stage of development (Khalifah 1966). There are reports of a decline in content of endogenous gibberellins in some other fruits during maturation (Hashimoto and Rappaport 1966;Jackson and Ooombe 1966) but it is difficult to think of a general decrease in the level of endogenous gibberellins in banana tissue as a cause of natural ripening in bananas, since application of GA3 induces ripening in banana slices (Fig. 4). Resolution of these anomalies appears dependent on the acquisition of knowledge on the mechanism of action of G~ in banana tissue. ...
Dipping of whole banana fruit in aqueous solutions of gibberellic acid (GAs) at concentrations of 10-L 10-2M delays ripening. In contrast, treatment of banana fruit slices by vacuum infiltration with GA3 at concentrations ranging from 10-6 to 10-2M accelerates ripening. These contrasting effects appear to be related to the differences in distribution of GA3 in the tissue, resulting from the two methods of treatment.
Obwohl seit vielen Jahren größte Zweifel am natürlichen Vorkommen der von KÖGL isolierten Auxine: Auxin a und Auxin b bestehen, scheint die Erwähnung dieser Verbindungen in der Literatur nicht mehr auszumerzen zu sein, was wohl zum Teil darauf zurückzuführen ist, daß die Nacharbeitungen der Köglschen Ansätze mit negativem Ergebnis eben nicht völlig stichhaltig sind. Es ist daher äußerst verdienstvoll, daß jetzt Vliegenhart u. Vliegenhart in Kögls ehemaligem Labor in der Rijksuniversiteit, Utrecht, die dort hinterlegten authentischen Proben der obigen Auxine aus den Jahren 1930–1940 mit Hilfe modernster physikalischer Methoden nachuntersucht haben. Massenspektren und Röntgendiagramme der Substanzen zeigten, daß die Proben von Auxin a mit Cholsäure, von Auxin b mit Thiosemicarbacid und von Auxin a-Lacton mit Hydrochinon identisch sind. Es ist ausgeschlossen, daß die Substanzen erst später vertauscht wurden, da z. B. das von KÖGL publizierte UV-Spektrum von ”Auxin a-Lacton„ dem von Hydrochinon genau gleicht. Keine der untersuchten Proben hatte die Zusammensetzung, die ursprünglich angenommen worden war. Auf Grund dieser Befunde müssen diese Auxine endgültig als nicht existent betrachtet werden. Unterstützt wird dieses Ergebnis noch dadurch, daß es Matsui u. Hwang erstmals gelang, ein Auxin dieser Reihe (Auxin b-Lacton) chemisch zu synthetisieren, und daß das racemische Produkt in verschiedenen Streckungswachstums- und Krümmungs-Tests praktisch keine biologische Aktivität zeigte (Nakamura, Takahashi, Matsui u. Hwang).
This chapter discusses the microbial production of gibberellins. Gibberellins (GAS), a large family of closely related diterpenoid acids biologically derived from tetracyclic diterpenoid hydrocarbon, represent an important group of potent plant growth hormones. This chapter discusses the chemistry and biosynthetic pathways of GAS. It illustrates the mode of action, structure–activity relationship of GAS. The uses of GA are also discussed. GA is a high-value industrially important biochemical in the international market, depending on the purity and potency. Therefore, its use at present is limited to high-premium crops. The industrial process currently used for fermentative production of GA3 is based on submerged fermentation (SmF) techniques. This chapter critically examines the existing as well as the potential techniques of fermentation and product recovery in the production of GAS.
During the first few hours of ageing, discs of Jerusalem artichoke tubers produce a stimulator of invertase synthesis, which can be detected in the ageing medium. Gibberellin-like substances, undetectable in extracts of freshly wounded tubers, are present in significant amounts after ageing. Tubers stored at 4 °C before wounding produce considerably more gibberellin than those stored at 20 °C. It is suggested that the stimulator observed is a gibberellin.
Thin-layer electrophoresis in conjunction with thin-layer chromatography proved an excellent method for separating gibberellin-like compounds extracted from small quantities of peach tissue. Eleven compounds active in the barley-endosperm gibberellin bioassay were separated from peach shoot tips. Two of these were possibly identical with known gibberellins but the remainder were distinctly different. Of the latter, five were acidic, one was neutral, and three were basic. The most active compound in shoot tips may have been GA1 or GA3 but in seeds the most active compound resembled no known gibberellin.
1. Amounts of gibberellin extractable from young bean seedlings using phosphate buffer, and following acid hydrolysis, or protease treatment, have been examined and compared with those obtained using methanol extraction. 2. Considerable differences in the amounts of gibberellins extractable are found for different batches of material. The level of extracted gibberellin is less for dry seeds and for 1-day old seedlings than for seedlings 4 days old. Before germination, the amounts of free, buffer-soluble, gibberellins are low, but these rise rapidly in the postgermination period. 3. The appearance of large amounts of free gibberellins in the cotyledons, believed to represent the conversion of bound forms, is not dependent upon the presence of the embryonic axis, since removal of this at planting has only a small effect on the amount of gibberellin extractable at day 4. There is evidence for synthesis of new gibberellin in the intact seedling by day 4. 4. α amylase activity in the cotyledons also develops in the absence of the embryo, but the high levels of activity shown by intact seedlings are not reached in cotyledons cultured in absence of the embryo.
Infection of the root system in tomato by the root-knot nematode was found to alter the gibberellins and cytokinina extracted from root tissue and xylum exudate. Gibberellins from the root tissue and xylem exudate of healthy plants occurred in the neutral, acidic, and aqueous fractions. With increasing levels of infection, gibberellins were primarily extracted in the slightly acidic fraction. Gibberellin activity in the neutral, acidic, and aqueous fractions was decreased in diseased plants. Cytokinins, which were also extracted from root tissue and xylem exudate, were lower in diseased plants than in uninfected plants.