The SUR2 gene of Arabidopsis thaliana encodes the cytochrome P450 CYP83B1, a modulator of auxin homeostasis.
Genetic screens have been performed to identify mutants with altered auxin homeostasis in Arabidopsis. A tagged allele of the auxin-overproducing mutant sur2 was identified within a transposon mutagenized population. The SUR2 gene was cloned and shown to encode the CYP83B1 protein, which belongs to the large family of the P450-dependent monooxygenases. SUR2 expression is up-regulated in sur1 mutants and induced by exogenous auxin in the wild type. Analysis of indole-3-acetic acid (IAA) synthesis and metabolism in sur2 plants indicates that the mutation causes a conditional increase in the pool size of IAA through up-regulation of IAA synthesis.
Barlier
I
I
Laboratoire de Biologie Cellulaire, Route de St. Cyr, F-78026 Versailles Cedex, France.
Kowalczyk
M
M
Marchant
A
A
Ljung
K
K
Bhalerao
R
R
Bennett
M
M
Sandberg
G
G
Bellini
C
C
D000483:Alleles; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D018744:DNA, Plant / Q000302:isolation & purification; D005786:Gene Expression Regulation; D017343:Genes, Plant; D006706:Homeostasis; D006863:Hydrogen-Ion Concentration; D007210:Indoleacetic Acids / Q000378:metabolism*; D007211:Indoles / Q000378:metabolism; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism*; D016254:Mutagenesis, Insertional; D010641:Phenotype; D018517:Plant Roots; D016133:Polymerase Chain Reaction / Q000379:methods; D012639:Seeds / Q000378:metabolism
D029681:Arabidopsis Proteins; D018744:DNA, Plant; D007210:Indoleacetic Acids; D007211:Indoles; C030737:indoleacetic acid; C030374:indole; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; C094565:CYP83A1 protein, Arabidopsis