The DWF4 gene of Arabidopsis encodes a cytochrome P450 that mediates multiple 22α-hydroxylation steps in brassinosteroid biosynthesis

Sunghwa Choe, Brian P. Dilkes, Shozo Fujioka, Suguru Takatsuto, Akira Sakurai, Kenneth A. Feldmann

Research output: Contribution to journalArticle

350 Scopus citations

Abstract

dwarf4 (dwf4) mutants of Arabidopsis display a dwarfed phenotype due to a lack of cell elongation. Dwarfism could be rescued by the application of brassinolide, suggesting that DWF4 plays a role in brassinosteroid (BR) biosynthesis. The DWF4 locus is defined by four mutant alleles. One of these is the result of a T-DNA insertion. Plant DNA flanking the insertion site was cloned and used as a probe to isolate the entire DWF4 gene. Sequence analysis revealed that DWF4 encodes a cytochrome P450 monooxygenase with 43% identity to the putative Arabidopsis steroid hydroxylating enzyme CONSTITUTIVE PHOTOMORPHOGENESIS AND DWARFISM. Sequence analysis of two other mutant alleles revealed deletions or a premature stop codon, confirming that DWF4 had been cloned. This sequence similarity suggests that DWF4 functions in specific hydroxylation steps during BR biosynthesis. In fact, feeding studies utilizing BR intermediates showed that only 22α-hydroxylated BRs rescued the dwf4 phenotype, confirming that DWF4 acts as a 22α-hydroxylase.

Original languageEnglish (US)
Pages (from-to)231-243
Number of pages13
JournalPlant Cell
Volume10
Issue number2
DOIs
StatePublished - Feb 1 1998

ASJC Scopus subject areas

  • Plant Science
  • Cell Biology

Fingerprint Dive into the research topics of 'The DWF4 gene of Arabidopsis encodes a cytochrome P450 that mediates multiple 22α-hydroxylation steps in brassinosteroid biosynthesis'. Together they form a unique fingerprint.

  • Cite this