title: Overexpression of 20-oxidase confers a gibberellin-overproduction phenotype in Arabidopsis.
abstract: In the gibberellin (GA) biosynthesis pathway, 20-oxidase catalyzes the oxidation and elimination of carbon-20 to give rise to C19-GAs. All bioactive GAs are C19-GAs. We have overexpressed a cDNA encoding 20-oxidase isolated from Arabidopsis seedlings in transgenic Arabidopsis plants. These transgenic plants display a phenotype that may be attributed to the overproduction of GA. The phenotype includes a longer hypocotyl, lighter-green leaves, increased stem elongation, earlier flowering, and decreased seed dormancy. However, the fertility of the transgenic plants is not affected. Increased levels of endogenous GA1, GA9, and GA20 were detected in seedlings of the transgenic line examined. GA4, which is thought to be the predominantly active GA in Arabidopsis, was not present at increased levels in this line. These results suggest that the overexpression of this 20-oxidase increases the levels of some endogenous GAs in transgenic seedlings, which causes the GA-overproduction phenotype.
authors.affiliation: Plant Growth and Development Group, Monsanto Company, 700 Chesterfield Parkway North, St. Louis, Missouri 63198, USA. shihshieh.huang@monsanto.com
authors.forename: S
authors.initials: S
authors.lastname: Huang
authors.forename: A S
authors.initials: AS
authors.lastname: Raman
authors.forename: J E
authors.initials: JE
authors.lastname: Ream
authors.forename: H
authors.initials: H
authors.lastname: Fujiwara
authors.forename: R E
authors.initials: RE
authors.lastname: Cerny
authors.forename: S M
authors.initials: SM
authors.lastname: Brown
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D001483:Base Sequence; D017931:DNA Primers; D018076:DNA, Complementary; D005875:Gibberellins / Q000378:metabolism*; D018546:Hypocotyl; D006899:Mixed Function Oxygenases / Q000235:genetics*; D010641:Phenotype; D030821:Plants, Genetically Modified; D012639:Seeds; D014170:Transformation, Genetic
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D005875:Gibberellins; D006899:Mixed Function Oxygenases; C089210:gibberellin, 2-oxoglutarate-oxygen oxidoreductase (20-hydroxylating, oxidizing)