The Arabidopsis ref2 Mutant Is Defective in the Gene Encoding CYP83A1 and Shows Both Phenylpropanoid and Glucosinolate Phenotypes

AUTOR(ES)

Hemm, Matthew R.

FONTE

American Society of Plant Biologists

RESUMO

The Arabidopsis ref2 mutant was identified in a screen for plants having altered fluorescence under UV light. Characterization of the ref2 mutants showed that they contained reduced levels of a number of phenylpropanoid pathway–derived products: sinapoylmalate in leaves, sinapoylcholine in seeds, and syringyl lignin in stems. Surprisingly, positional cloning of the REF2 locus revealed that it encodes CYP83A1, a cytochrome P450 sharing a high degree of similarity to CYP83B1, an enzyme involved in glucosinolate biosynthesis. Upon further investigation, ref2 mutants were found to have reduced levels of all aliphatic glucosinolates and increased levels of indole-derived glucosinolates in their leaves. These results show that CYP83A1 is involved in the biosynthesis of both short-chain and long-chain aliphatic glucosinolates and suggest a novel metabolic link between glucosinolate biosynthesis, a secondary biosynthetic pathway found only in plants in the order Capparales, and phenylpropanoid metabolism, a pathway found in all plants and considered essential to the survival of terrestrial plant species.

Documentos Relacionados

• CYP83A1 and CYP83B1, Two Nonredundant Cytochrome P450 Enzymes Metabolizing Oximes in the Biosynthesis of Glucosinolates in Arabidopsis1
• The Involvement of Two P450 Enzymes, CYP83B1 and CYP83A1, in Auxin Homeostasis and Glucosinolate Biosynthesis1
• CYP83B1, a Cytochrome P450 at the Metabolic Branch Point in Auxin and Indole Glucosinolate Biosynthesis in Arabidopsis
• An Arabidopsis mutant defective in the general phenylpropanoid pathway.
• A Glucosinolate Mutant of Arabidopsis Is Thermosensitive and Defective in Cytosolic Hsp90 Expression after Heat Stress1