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  • The EMBO Journal (2004) 23, 2903 - 2913
  • doi:10.1038/sj.emboj.7600290

Published online: 8 July 2004

Arabidopsis CYP86A2 represses Pseudomonas syringae type III genes and is required for cuticle development

Fangming Xiao1, S Mark Goodwin2, Yanmei Xiao1, Zhaoyu Sun1, Douglas Baker1, Xiaoyan Tang1, Matthew A Jenks2 and Jian-Min Zhou1,3

  1. Department of Plant Pathology, Kansas State University, Manhattan, KS, USA
  2. Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN, USA
  3. National Institute of Biological Sciences, Beijing

Correspondence to:

Jian-Min Zhou, Department of Plant Pathology, Kansas State University, 4024 Throckmorton Plant Science Center, Manhattan, KS, USA. Tel.: +1 785 532 2415; Fax: +1 785 532 5692; E-mail: jzhou@ksu.edu

Received 12 January 2004; Accepted 7 June 2004

Pseudomonas syringae relies on type III secretion system to deliver effector proteins into the host cell for parasitism. Type III genes are induced in planta, but host factors affecting the induction are poorly understood. Here we report on the identification of an Arabidopsis mutant, att1 (for aberrant induction of type three genes), that greatly enhances the expression of bacterial type III genes avrPto and hrpL. att1 plants display enhanced disease severity to a virulent strain of P. syringae, suggesting a role of ATT1 in disease resistance. ATT1 encodes CYP86A2, a cytochrome P450 monooxygenase catalyzing fatty acid oxidation. The cutin content is reduced to 30% in att1, indicating that CYP86A2 plays a major role in the biosynthesis of extracellular lipids. att1 has a loose cuticle membrane ultrastructure and shows increased permeability to water vapor, demonstrating the importance of the cuticle membrane in controlling water loss. The enhanced avrPto-luc expression is specific to att1, but not another cuticle mutant, wax2. The results suggest that certain cutin-related fatty acids synthesized by CYP86A2 may repress bacterial type III gene expression in the intercellular spaces.

  • Keywords:

    • Arabidopsis,
    • cutin,
    • disease resistance,
    • Pseudomonas,
    • type III secretion system