Figure 1.

The Arabidopsis ref5-1 Mutant Is Defective in CYP83B1.

(A) Representative photographs of wild-type (Col-0) and ref5-1 plants under white light or UV light. Plants were compared 3 weeks after planting.

(B) Map-based cloning of the REF5 gene. The REF5 locus was mapped to a 6-BAC interval at the bottom of chromosome 4 defined by markers Cer449753 and Cer452102 (vertical bars). The annotation of three candidate genes within this interval, a cinnamoyl-CoA reductase-like protein (CCR like; At4g30470), a serine carboxypeptidase II-like protein (SCPL; At4g30610), and a cytochrome P450 monooxygenase 83B1 (CYP83B1; At4g31500), suggested that they might be involved in phenylpropanoid synthesis.

(C) Gene organization of REF5 and schematic representation of ref5-1 and ref5-2 mutants. White box indicates exons, gray box in second exon indicates the heme binding region, and the intervening line denotes an intron. The location of the T-DNA insertion in ref5-2 (SALK_028573) is shown above the genomic structure. The arrow indicates mutation position in ref5-1.