Functional identification of AtTPS03 as (E)-beta-ocimene synthase: a monoterpene synthase catalyzing jasmonate- and wound-induced volatile formation in Arabidopsis thaliana.
(E)-beta-Ocimene is one of the most commonly found monoterpenes of the volatile blends that are emitted from leaves in response to damage by herbivores or mechanical wounding. (E)-beta-Ocimene is also a component of many floral scents. Airborne (E)-beta-ocimene emitted from plants can serve as a chemical cue for the attraction of parasitoids or predators of plant herbivores and also as an attractant for pollinating insects. Furthermore, exposure of plants to (E)-beta-ocimene can activate defense gene expression. In this paper, we describe cDNA cloning and functional characterization of a gene encoding a highly specialized (E)-beta-ocimene synthase, AtTPS03, from Arabidopsis thaliana (L.) Heynh. AtTPS03 was identified as a member of the large AtTPS gene family of putative terpene synthases. A cDNA for AtTPS03 was expressed in Escherichia coli and the enzyme function identified in vitro. The A. thaliana (E)-beta-ocimene synthase produces almost exclusively (E)-beta-ocimene (94%) with minor amounts of the related acyclic monoterpenes (Z)-beta-ocimene (4%) and myrcene (2%). Transcripts for AtTPS03 were up-regulated in leaves of Arabidopsis in response to mechanical wounding and treatment with jasmonic acid, concurrent with induced emission of (E)-beta-ocimene. AtTPS03 provides an important gene for probing plant-insect and possibly plant-plant interactions mediated by terpenoid volatiles.
Fäldt
Jenny
J
Biotechnology Laboratory, Department of Botany, University of British Columbia, 237-6174 University Boulevard, Vancouver, V6T 1Z3, B.C., Canada.
Arimura
Gen-ichiro
G
Gershenzon
Jonathan
J
Takabayashi
Junji
J
Bohlmann
Jörg
J
D000080462:Acyclic Monoterpenes; D000475:Alkenes / Q000737:chemistry / Q000378:metabolism; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D003517:Cyclopentanes / Q000378:metabolism*; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D019753:Intramolecular Lyases / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D039821:Monoterpenes / Q000378:metabolism*; D054883:Oxylipins; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013314:Stress, Mechanical; D014835:Volatilization
D000080462:Acyclic Monoterpenes; D000475:Alkenes; D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D018076:DNA, Complementary; D039821:Monoterpenes; D054883:Oxylipins; C443996:beta-ocimene; C011006:jasmonic acid; D019753:Intramolecular Lyases; C108134:TPS10 protein, Arabidopsis