Gibberellin dose-response regulation of GA4 gene transcript levels in Arabidopsis.

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,...

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Автори: Cowling, R, Kamiya, Y, Seto, H, Harberd, N
Формат: Journal article
Мова:English
Опубліковано: 1998
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author Cowling, R
Kamiya, Y
Seto, H
Harberd, N
author_facet Cowling, R
Kamiya, Y
Seto, H
Harberd, N
author_sort Cowling, R
collection OXFORD
description 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 3beta-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 GA4 (the product of 3beta-hydroxylation) but not by its immediate precursor GA9 (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 3beta-hydroxylated GAs, being also exhibited by structures that were not 3beta-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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spelling oxford-uuid:99370c76-6e00-4d44-9360-b59a0cfd23f82022-03-27T00:12:48ZGibberellin dose-response regulation of GA4 gene transcript levels in Arabidopsis.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:99370c76-6e00-4d44-9360-b59a0cfd23f8EnglishSymplectic Elements at Oxford1998Cowling, RKamiya, YSeto, HHarberd, NThe 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 3beta-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 GA4 (the product of 3beta-hydroxylation) but not by its immediate precursor GA9 (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 3beta-hydroxylated GAs, being also exhibited by structures that were not 3beta-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.
spellingShingle Cowling, R
Kamiya, Y
Seto, H
Harberd, N
Gibberellin dose-response regulation of GA4 gene transcript levels in Arabidopsis.
title Gibberellin dose-response regulation of GA4 gene transcript levels in Arabidopsis.
title_full Gibberellin dose-response regulation of GA4 gene transcript levels in Arabidopsis.
title_fullStr Gibberellin dose-response regulation of GA4 gene transcript levels in Arabidopsis.
title_full_unstemmed Gibberellin dose-response regulation of GA4 gene transcript levels in Arabidopsis.
title_short Gibberellin dose-response regulation of GA4 gene transcript levels in Arabidopsis.
title_sort gibberellin dose response regulation of ga4 gene transcript levels in arabidopsis
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AT kamiyay gibberellindoseresponseregulationofga4genetranscriptlevelsinarabidopsis
AT setoh gibberellindoseresponseregulationofga4genetranscriptlevelsinarabidopsis
AT harberdn gibberellindoseresponseregulationofga4genetranscriptlevelsinarabidopsis