OPEN ACCESS ARTICLE

This Article Free via Open Access: OA OA Full Text Full Text (PDF) Supplemental Data OA All Versions of this Article: 21/6/1830    most recent tpc.109.066670v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Böttcher, C. Articles by Glawischnig, E. Search for Related Content PubMed PubMed Citation Articles by Böttcher, C. Articles by Glawischnig, E. Agricola Articles by Böttcher, C. Articles by Glawischnig, E.

The Multifunctional Enzyme CYP71B15 (PHYTOALEXIN DEFICIENT3) Converts Cysteine-Indole-3-Acetonitrile to Camalexin in the Indole-3-Acetonitrile Metabolic Network of Arabidopsis thaliana^[W],[OA]

^a Department of Stress and Developmental Biology, Leibniz Institute of Plant Biochemistry, 06120 Halle/Saale, Germany
^b Lehrstuhl für Genetik, Technische Universität München, 85350 Freising, Germany

¹ Address correspondence to egl{at}wzw.tum.de.

Accumulation of camalexin, the characteristic phytoalexin of Arabidopsis thaliana, is induced by a great variety of plant pathogens. It is derived from Trp, which is converted to indole-3-acetonitrile (IAN) by successive action of the cytochrome P450 enzymes CYP79B2/B3 and CYP71A13. Extracts from wild-type plants and camalexin biosynthetic mutants, treated with silver nitrate or inoculated with Phytophthora infestans, were comprehensively analyzed by ultra-performance liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry. This metabolomics approach was combined with precursor feeding experiments to characterize the IAN metabolic network and to identify novel biosynthetic intermediates and metabolites of camalexin. Indole-3-carbaldehyde and indole-3-carboxylic acid derivatives were shown to originate from IAN. IAN conjugates with glutathione, -glutamylcysteine, and cysteine [Cys(IAN)] accumulated in challenged phytoalexin deficient3 (pad3) mutants. Cys(IAN) rescued the camalexin-deficient phenotype of cyp79b2 cyp79b3 and was itself converted to dihydrocamalexic acid (DHCA), the known substrate of CYP71B15 (PAD3), by microsomes isolated from silver nitrate–treated Arabidopsis leaves. Surprisingly, yeast-expressed CYP71B15 also catalyzed thiazoline ring closure, DHCA formation, and cyanide release with Cys(IAN) as substrate. In conclusion, in the camalexin biosynthetic pathway, IAN is derivatized to the intermediate Cys(IAN), which serves as substrate of the multifunctional cytochrome P450 enzyme CYP71B15.

This article has been cited by other articles:

				A. D. Hegeman Plant metabolomics--meeting the analytical challenges of comprehensive metabolite analysis Briefings in Functional Genomics, January 11, 2010; (2010) elp053v1. [Abstract] [Full Text] [PDF]

				M. Morant, C. Ekstrom, P. Ulvskov, C. Kristensen, M. Rudemo, C. E. Olsen, J. Hansen, K. Jorgensen, B. Jorgensen, B. L. Moller, et al. Metabolomic, Transcriptional, Hormonal, and Signaling Cross-Talk in Superroot2 Mol Plant, January 1, 2010; 3(1): 192 - 211. [Abstract] [Full Text] [PDF]