The SUR2 gene of Arabidopsis thaliana encodes the cytochrome P450 CYP83B1, a modulator of auxin homeostasis

Isabelle Barlier (1) , Mariusz Kowalczyk (2) , Alan Marchant (3) , Karin Ljung (2) , Rishikest Bhalerao (2) , Malcolm Bennett (3) , Goeran Sandberg (2) , Catherine Bellini (4)

1 UR 0501 Laboratoire de Biologie Cellulaire
2 Department of Forest Genetics and Plant Physiology
3 UON - University of Nottingham, UK
4 Laboratoire de biologie cellulaire et moléculaire

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.

Domaines: Sciences du Vivant [q-bio]

Isabelle Barlier, Mariusz Kowalczyk, Alan Marchant, Karin Ljung, Rishikest Bhalerao, et al.. The SUR2 gene of Arabidopsis thaliana encodes the cytochrome P450 CYP83B1, a modulator of auxin homeostasis. Proceedings of the National Academy of Sciences of the United States of America, 2000, 97 (26), pp.14819-14824. ⟨10.1073/pnas.260502697⟩. ⟨hal-02699182⟩