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First published online June 9, 2006; 10.1104/pp.106.082024 Plant Physiology 141:1248-1254 (2006) © 2006 American Society of Plant Biologists CYP71B15 (PAD3) Catalyzes the Final Step in Camalexin Biosynthesis1 Svato![]() Lehrstuhl für Genetik, Technische Universität München, D85350 Freising, Germany (R.S., E.G.); Center for Molecular Plant Physiology, DK1871 Frederiksberg C, Denmark (M.N., B.L.P., C.E.O., B.A.H.); and Max Planck Institute for Chemical Ecology, Beutenberg Campus, D07745 Jena, Germany (M.M., A.S.)
Camalexin represents the main phytoalexin in Arabidopsis (Arabidopsis thaliana). The camalexin-deficient phytoalexin deficient 3 (pad3) mutant has been widely used to assess the biological role of camalexin, although the exact substrate of the cytochrome P450 enzyme 71B15 encoded by PAD3 remained elusive. 2-(Indol-3-yl)-4,5-dihydro-1,3-thiazole-4-carboxylic acid (dihydrocamalexic acid) was identified as likely intermediate in camalexin biosynthesis downstream of indole-3-acetaldoxime, as it accumulated in leaves of silver nitrate-induced pad3 mutant plants and it complemented the camalexin-deficient phenotype of a cyp79b2/cyp79b3 double-knockout mutant. Recombinant CYP71B15 heterologously expressed in yeast catalyzed the conversion of dihydrocamalexic acid to camalexin with preference of the (S)-enantiomer. Arabidopsis microsomes isolated from leaves of CYP71B15-overexpressing and induced wild-type plants were capable of the same reaction but not microsomes from induced leaves of pad3 mutants. In conclusion, CYP71B15 catalyzes the final step in camalexin biosynthesis.
1 This work was supported by the Deutsche Forschungsgemeinschaft (GL346/1) and the Max-Planck Gesellschaft. The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Erich Glawischnig (egl{at}wzw.tum.de). Article, publication date, and citation information can be found at www.plantphysiol.org/cgi/doi/10.1104/pp.106.082024. * Corresponding author; e-mail egl{at}wzw.tum.de; fax 498161715636. Received April 13, 2006; returned for revision May 18, 2006; accepted May 24, 2006. This article has been cited by other articles:
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