Relationships between structure and growth-promoting activity of the gibberellins and some allied compounds, in four test systems

Brian, P. W.; Grove, John Frederick; Mulholland, T. P. C.

doi:10.1016/s0031-9422(00)82941-6

Cited by 75 publications

(24 citation statements)

References 22 publications

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“…We found that a 3␣-OH group (epi-GA 4 ) and a 3ϭO group (3-oxo-GA 9 ) could each substitute for the 3␤-OH group on the GA 4 skeleton, creating molecules that were active in the regulation of both GA4 transcript levels and hypocotyl elongation. Earlier experiments demonstrated that epi-GA 4 and 3-oxo-GA 9 are active in the regulation of cucumber hypocotyl elongation (Brian et al, 1967). In addition, recent experiments using the d1 mutant of maize have shown that GA 5 , which lacks a 3␤-OH Figure 5.…”

Section: Discussionmentioning

confidence: 99%

Gibberellin Dose-Response Regulation of GA4 Gene Transcript Levels in Arabidopsis1

Kamiya²,

et al. 1998

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The gibberellins (GAs) are a complex family of diterpenoid compounds, some of which are potent endogenous regulators of plant growth. As part of a feedback control of endogenous GA levels, active GAs negatively regulate the abundance of mRNA transcripts encoding GA biosynthesis enzymes. For example, Arabidopsis GA4 gene transcripts encode GA 3␤-hydroxylase, an enzyme that catalyzes the conversion of inactive to active GAs. Here we show that active GAs regulate GA4 transcript abundance in a dose-dependent manner, and that down-regulation of GA4 transcript abundance is effected by GA 4 (the product of 3␤-hydroxylation) but not by its immediate precursor GA 9 (the substrate). Comparison of several different GA structures showed that GAs active in promoting hypocotyl elongation were also active in regulating GA4 transcript abundance, suggesting that similar GA:receptor and subsequent signal transduction processes control these two responses. It is interesting that these activities were not restricted to 3␤-hydroxylated GAs, being also exhibited by structures that were not 3␤-hydroxylated but that had another electronegative group at C-3. We also show that GA-mediated control of GA4 transcript abundance is disrupted in the GA-response mutants gai and spy-5. These observations define a sensitive homeostatic mechanism whereby plants may regulate their endogenous GA levels.

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Section: Discussionmentioning

confidence: 99%

Gibberellin Dose-Response Regulation of GA4 Gene Transcript Levels in Arabidopsis1

Kamiya²,

et al. 1998

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“…(ethyl acetate -light petroleum, 2:3 run twice). This oily diol (6, 20 mg) had r 2.4-2.9 (5H, aromatic protons), 6.80 (dd, 1 H-3, wllz = 15 Hz), 9.02 (s, 6H, quaternary C-CH3's), and 9.20 (s, 3H, quaternary C-CH,); vo-, 3633 and 3610 cm-I. Rapid decomposition of 6 to the styrene 5 was taking place and further investigations were limited to 5 (see below).…”

Section: Preparation Of D I O Lmentioning

confidence: 98%

Microbiological Transformations of 17-Norkauran-16-one, ent-17-Norkauran-16-one, and 17-Norphyllocladan-16-one by Aspergillusniger

Anderson¹,

McCrindle²,

Turnbull³

1975

Can. J. Chem.

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. Can. J. Chem. 53,1181Chem. 53, (1975.Incubation of 17-norkauran-16-one (3b) and ent-17-norkauran-16-one (2b) with Aspergillus niger gives the related C-3 equatorial alcohols 3c and 2c, respectively, whereas 17-norphyllocladan-16-one (4b) gives the 3p-alcohol4c and the corresponding 3-ketone 4g. Yields of all of these products are low. Diketone 4g is identical with the corresponding compound derived from calliterpenone, thus confirming that calliterpenone should be formulated as 8 rather than 7. Chem. 53,1181Chem. 53, (1975. ALLAN B. ANDERSON, ROBERT MCCRINDLELes incubations de la nor-17 kauranone-16 (3b) et de I'ent-nor-17 kauranone-16 (2b) avec I'Aspergillus niger conduisent respectivement aux alcools Bquatoriaux en position 3 (3c et 2c) alors que la nor-17 phyllocladanone-16 (4b) conduit a I'alcool 38 (4c) et au dtrivt ckto-3 correspondant (4g). Les rendements de tous ces produits sont bas. La didtone 4g est identique avec le compost correspondant obtenu ? I partir de la calliterptnone; ceci confirme donc que la calliterptnone doit Stre reprksentte par la formule 8 plutBt que 7.[Traduit par le journal]The gibberellins (2) have attracted a large portion of diterpenoid research mainly because of their influence on the growth and development of plants. All known gibberellins are thought to have the gibbane skeleton (1) and to be biosynthesized in plants via ent-16-kaurene (2a) or a derivative of this diterpene. Other tetracyclic diterpenes, such as kaurene (3a) and phyllocladene (13P-kaurene; 4a) occur (3) naturally and we have been seeking evidence for the occurrence of gibberellin-like compounds derived from these. A study of the gibberellins in plants which produce 3a or 4a would be an obvious approach in this quest. However, since fresh tissue of such plants has not been obtainable by us3 in sufficient quantity we have undertaken a less direct attack.This approach was suggested by observations 'For a preliminary account of part of this work see. ref.1. 2To whom correspondence should be addressed. 3Another group has failed (4) in an attempt to isolate the gibberellins from a variety of Cryptomeria japonica which contains (5) 4a.(6) that although ent-kaurene itself has little gibberellin activity, various oxygenated derivatives, all of which contain the ring D exo-methylene group, do exhibit significant physiological effects. We' planned to submit analogous kaurene and phyllocladene derivatives for testing in bioassays that are specific for gibberellins but since such compounds were not available, synthetic routes from the parent hydrocarbons (3a and 4a) were sought. The present paper deals with an investigation of microbial oxygenation as a means of producing the desired derivatives.Initially, microbial hydroxylation of the more available ent-kaurene system was studied as a model. The norketone 2b was chosen as a suitable substrate for two reasons. First, carbonyl containing compounds have been successfully used (7,8) in related steroidal work and second, the C-17 methylene group could be readily reattac...

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“…Smith et al (1991) detected only GA, in cucumber after immunochromatographic purification, at levels approximately one-fifth of those of GA,. Taking into account this and the fact that exogenously applied GA, is far more active than GA, in promoting cucumber hypocotyl elongation (Brian et al, 1967), we did not continue the analysis of GA, in subsequent samples. The data in Table I and Figure 5 show that a phydependent difference in growth rate can appear without any increase of endogenous GA, (WT-with Figure 3 since the segments contain approximately equ,il numbers of cells.…”

Section: Phyb and The Endogenous Level Of Casmentioning

confidence: 99%

Phytochrome, Gibberellins, and Hypocotyl Growth (A Study Using the Cucumber (Cucumis sativus L.) long hypocotyl Mutant)

et al. 1995

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The possible involvement of gibberellins (CAs) in the regulation of hypocotyl elongation by phytochrome was examined. Under white light the tal1 long hypocotyl (Ih) cucumber (Cucumis sativus L.) mutant, deficient in a type B-like phytochrome, shows an increased "responsiveness" (defined as response capability) to applied CA, (the main endogenous active CA) compared to the wild type. Supplementing far-red irradiation results in a similar increase in responsiveness in the wild type. Experiments involving application of the precursor GA, and of an inhibitor of CA, inactivation suggest that both the GA, activation and inactivation steps are phytochrome independent. Endogenous C A levels of whole seedlings were analyzed by combined gas chromatography-mass spectrometry using deuterated interna1 standards. The levels of GA, (and those of CA,,, the inactivated CA,) were lower in the //I mutant under low-irradiance fluorescent light compared with the wild type, similar to wild type under higher irradiance light during the initial hypocotyl extension phase, and higher during the phase of sustained growth, in which extension involved an increase in the number of cells in the upper region. In all cases, growth of the Ih mutant was more rapid than that of the wild type. It is proposed that CA, and phytochrome control cell elongation primarily through separate mechanisms that interact at a step close to the terminal response.

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Relationships between structure and growth-promoting activity of the gibberellins and some allied compounds, in four test systems

Cited by 75 publications

References 22 publications

Gibberellin Dose-Response Regulation of GA4 Gene Transcript Levels in Arabidopsis1

Gibberellin Dose-Response Regulation of GA4 Gene Transcript Levels in Arabidopsis1

Microbiological Transformations of 17-Norkauran-16-one, ent-17-Norkauran-16-one, and 17-Norphyllocladan-16-one by Aspergillusniger

Phytochrome, Gibberellins, and Hypocotyl Growth (A Study Using the Cucumber (Cucumis sativus L.) long hypocotyl Mutant)

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