A plant thiolase involved in benzoic acid biosynthesis and volatile benzenoid production

Authors

  • Alex Van Moerkercke,

    1. Department of Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands, and
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  • Ines Schauvinhold,

    1. Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
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  • Eran Pichersky,

    1. Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
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  • Michel A. Haring,

    1. Department of Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands, and
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  • Robert C. Schuurink

    Corresponding author
    1. Department of Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands, and
      *For correspondence (fax +31 205 257934; e-mail r.c.schuurink@uva.nl).
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*For correspondence (fax +31 205 257934; e-mail r.c.schuurink@uva.nl).

Summary

The exact biosynthetic pathways leading to benzoic acid (BA) formation in plants are not known, but labeling experiments indicate the contribution of both β-oxidative and non-β-oxidative pathways. In Petunia hybrida BA is a key precursor for the production of volatile benzenoids by its flowers. Using functional genomics, we identified a 3-ketoacyl-CoA thiolase, PhKAT1, which is involved in the benzenoid biosynthetic pathway and the production of BA. PhKAT1 is localised in the peroxisomes, where it is important for the formation of benzoyl-CoA-related compounds. Silencing of PhKAT1 resulted in a major reduction in BA and benzenoid formation, leaving the production of other phenylpropanoid-related volatiles unaffected. During the night, when volatile benzenoid production is highest, it is largely the β-oxidative pathway that contributes to the formation of BA and benzenoids. Our studies add the benzenoid biosynthetic pathway to the list of pathways in which 3-ketoacyl-CoA thiolases are involved in plants.

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