Arabidopsis CYP94B3 Encodes jasmonyl-L-isoleucine 12-hydroxylase, a Key Enzyme in the Oxidative Catabolism of Jasmonate

Plant Cell Physiol. 2011 Oct;52(10):1757-65. doi: 10.1093/pcp/pcr110. Epub 2011 Aug 17.

Abstract

The hormonal action of jasmonate in plants is controlled by the precise balance between its biosynthesis and catabolism. It has been shown that jasmonyl-L-isoleucine (JA-Ile) is the bioactive form involved in the jasmonate-mediated signaling pathway. However, the catabolism of JA-Ile is poorly understood. Although a metabolite, 12-hydroxyJA-Ile, has been characterized, detailed functional studies of the compound and the enzyme that produces it have not been conducted. In this report, the kinetics of wound-induced accumulation of 12-hydroxyJA-Ile in plants were examined, and its involvement in the plant wound response is described. Candidate genes for the catabolic enzyme were narrowed down from 272 Arabidopsis Cyt P450 genes using Arabidopsis mutants. The candidate gene was functionally expressed in Pichia pastoris to reveal that CYP94B3 encodes JA-Ile 12-hydroxylase. Expression analyses demonstrate that expression of CYP94B3 is induced by wounding and shows specific activity toward JA-Ile. Plants grown in medium containing JA-Ile show higher sensitivity to JA-Ile in cyp94b3 mutants than in wild-type plants. These results demonstrate that CYP94B3 plays a major regulatory role in controlling the level of JA-Ile in plants.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / drug effects
  • Arabidopsis / enzymology*
  • Arabidopsis / genetics
  • Cyclopentanes / chemistry
  • Cyclopentanes / metabolism*
  • Cyclopentanes / pharmacology
  • Cytochrome P-450 Enzyme System / genetics
  • Cytochrome P-450 Enzyme System / metabolism*
  • Gene Expression Regulation, Enzymologic / drug effects
  • Gene Expression Regulation, Plant / drug effects
  • Gene Knockout Techniques
  • Genetic Testing
  • Isoleucine / analogs & derivatives
  • Isoleucine / chemistry
  • Isoleucine / metabolism
  • Kinetics
  • Mixed Function Oxygenases / genetics
  • Mixed Function Oxygenases / metabolism*
  • Mutation / genetics
  • Oligonucleotide Array Sequence Analysis
  • Oxidation-Reduction / drug effects
  • Oxylipins / metabolism*
  • Oxylipins / pharmacology
  • Phenotype
  • Plant Leaves / drug effects
  • Plant Leaves / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Salicylic Acid / pharmacology
  • Substrate Specificity / drug effects

Substances

  • Cyclopentanes
  • Oxylipins
  • jasmonoyl-isoleucine
  • Isoleucine
  • jasmonic acid
  • Cytochrome P-450 Enzyme System
  • Mixed Function Oxygenases
  • cytochrome P-450 94B3, Arabidopsis
  • Salicylic Acid