title: CYP79D enzymes contribute to jasmonic acid-induced formation of aldoximes and other nitrogenous volatiles in two Erythroxylum species.
abstract: Amino acid-derived aldoximes and nitriles play important roles in plant defence. They are well-known as precursors for constitutive defence compounds such as cyanogenic glucosides and glucosinolates, but are also released as volatiles after insect feeding. Cytochrome P450 monooxygenases (CYP) of the CYP79 family catalyze the formation of aldoximes from the corresponding amino acids. However, the majority of CYP79s characterized so far are involved in cyanogenic glucoside or glucosinolate biosynthesis and only a few have been reported to be responsible for nitrogenous volatile production.
  
  
  
  In this study we analysed and compared the jasmonic acid-induced volatile blends of two Erythroxylum species, the cultivated South American crop species E. coca and the African wild species E. fischeri. Both species produced different nitrogenous compounds including aliphatic aldoximes and an aromatic nitrile. Four isolated CYP79 genes (two from each species) were heterologously expressed in yeast and biochemically characterized. CYP79D62 from E. coca and CYP79D61 and CYP79D60 from E. fischeri showed broad substrate specificity in vitro and converted L-phenylalanine, L-isoleucine, L-leucine, L-tryptophan, and L-tyrosine into the respective aldoximes. In contrast, recombinant CYP79D63 from E. coca exclusively accepted L-tryptophan as substrate. Quantitative real-time PCR revealed that CYP79D60, CYP79D61, and CYP79D62 were significantly upregulated in jasmonic acid-treated Erythroxylum leaves.
  
  
  
  The kinetic parameters of the enzymes expressed in vitro coupled with the expression patterns of the corresponding genes and the accumulation and emission of (E/Z)-phenylacetaldoxime, (E/Z)-indole-3-acetaldoxime, (E/Z)-3-methylbutyraldoxime, and (E/Z)-2-methylbutyraldoxime in jasmonic acid-treated leaves suggest that CYP79D60, CYP79D61, and CYP79D62 accept L-phenylalanine, L-leucine, L-isoleucine, and L-tryptophan as substrates in vivo and contribute to the production of volatile and semi-volatile nitrogenous defence compounds in E. coca and E. fischeri.
authors.affiliation: Max Planck Institute for Chemical Ecology, Hans-Knöll-Strasse 8, D-07745, Jena, Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Luck
authors.affiliation: Max Planck Institute for Chemical Ecology, Hans-Knöll-Strasse 8, D-07745, Jena, Germany.|Present address: Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Forckenbeckstrasse 6, D-52074, Aachen, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Jirschitzka
authors.affiliation: Max Planck Institute for Chemical Ecology, Hans-Knöll-Strasse 8, D-07745, Jena, Germany.|Present address: Michael Smith Laboratories, University of British Columbia, Vancouver, Canada.
authors.forename: Sandra
authors.initials: S
authors.lastname: Irmisch
authors.affiliation: Max Planck Institute for Chemical Ecology, Hans-Knöll-Strasse 8, D-07745, Jena, Germany.
authors.forename: Meret
authors.initials: M
authors.lastname: Huber
authors.affiliation: Max Planck Institute for Chemical Ecology, Hans-Knöll-Strasse 8, D-07745, Jena, Germany.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Gershenzon
authors.affiliation: Max Planck Institute for Chemical Ecology, Hans-Knöll-Strasse 8, D-07745, Jena, Germany. koellner@ice.mpg.de.
authors.forename: Tobias G
authors.initials: TG
authors.lastname: Köllner
mesh_terms: D000595:Amino Acid Sequence; D003041:Coca / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D003517:Cyclopentanes / Q000378:metabolism*; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017672:Nitrogen Compounds / Q000378:metabolism*; D010091:Oximes / Q000378:metabolism*; D054883:Oxylipins / Q000378:metabolism*; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D016415:Sequence Alignment; D013045:Species Specificity; D055549:Volatile Organic Compounds / Q000378:metabolism
chemical_list: D003517:Cyclopentanes; D017672:Nitrogen Compounds; D010091:Oximes; D054883:Oxylipins; D010940:Plant Proteins; D055549:Volatile Organic Compounds; C011006:jasmonic acid; D003577:Cytochrome P-450 Enzyme System
keywords: Aldoxime; CYP79; Cytochrome P450 monooxygenase; Erythroxylum; Volatiles