Title: | Herbivore-induced defense response in a model legume. Two-spotted spider mites induce emission of (E)-beta-ocimene and transcript accumulation of (E)-beta-ocimene synthase in Lotus japonicus |
Author(s): | Arimura G; Ozawa R; Kugimiya S; Takabayashi J; Bohlmann J; |
Address: | "Biotechnology Laboratory, Department of Botany, and Department of Forest Sciences, University of British Columbia, Vancouver V6T 1Z3, British Columbia, Canada. garimura@ice.mpg.de" |
ISSN/ISBN: | 0032-0889 (Print) 1532-2548 (Electronic) 0032-0889 (Linking) |
Abstract: | "Indirect defense of plants against herbivores often involves the induced emission of volatile infochemicals including terpenoids that attract natural enemies of the herbivores. We report the isolation and characterization of a terpene synthase cDNA (LjEbetaOS) from a model legume, Lotus japonicus. Recombinant LjEbetaOS enzyme produced (E)-beta-ocimene (98%) and its Z-isomer (2%). Transcripts of LjEbetaOS were induced in L. japonicus plants infested with two-spotted spider mites (Tetranychus urticae), coinciding with increasing emissions of (E)-beta-ocimene as well as other volatiles, (Z)-3-hexenyl acetate and (E)-4,8-dimethyl-1,3,7-nonatriene, by the infested plants. We suggest that LjEbetaOS is involved in the herbivore-induced indirect defense response of spider mite-infested L. japonicus via de novo formation and emission (E)-beta-ocimene. Mechanical wounding of the leaves or application of alamethicin (ALA), a potent fungal elicitor of plant volatile emission, also induced transiently increased levels of LjEbetaOS transcripts in L. japonicus. However, wounding or ALA did not result in elevated release of (E)-beta-ocimene. Differences in volatile emissions after herbivory, mechanical wounding, or treatment with ALA suggest that neither a single mechanical wounding event nor ALA simulate the effect of herbivore activity and indicate that herbivore-induced emission of (E)-beta-ocimene in L. japonicus involves control mechanisms in addition to up-regulation of LjEbetaOS transcripts" |
Keywords: | "Acyclic Monoterpenes Alkenes/*metabolism Amino Acid Sequence Animals Cloning, Molecular Conserved Sequence DNA, Complementary/genetics Escherichia coli/enzymology/genetics Lotus/enzymology/*genetics/*parasitology Mites/*physiology Molecular Sequence Data;" |
Notes: | "MedlineArimura, Gen-ichiro Ozawa, Rika Kugimiya, Soichi Takabayashi, Junji Bohlmann, Jorg eng Research Support, Non-U.S. Gov't 2004/08/18 Plant Physiol. 2004 Aug; 135(4):1976-83. doi: 10.1104/pp.104.042929. Epub 2004 Aug 13" |