Abstract
Maize and a variety of other plant species release volatile compounds in response to herbivore attack that serve as chemical cues to signal natural enemies of the feeding herbivore. N-(17-hydroxylinolenoyl)-l-glutamine is an elicitor component that has been isolated and chemically characterized from the regurgitant of the herbivore-pest beet armyworm. This fatty acid derivative, referred to as volicitin, triggers the synthesis and release of volatile components, including terpenoids and indole in maize. Here we report on a previously unidentified enzyme, indole-3-glycerol phosphate lyase (IGL), that catalyzes the formation of free indole and is selectively activated by volicitin. IGL's enzymatic properties are similar to BX1, a maize enzyme that serves as the entry point to the secondary defense metabolites DIBOA and DIMBOA. Gene-sequence analysis indicates that Igl and Bx1 are evolutionarily related to the tryptophan synthase alpha subunit.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Base Sequence
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DNA, Plant
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Fatty Acids / metabolism*
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Gene Expression Regulation, Enzymologic*
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Gene Expression Regulation, Plant*
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Genes, Plant
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Glutamine / analogs & derivatives
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Glutamine / metabolism*
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Glycerophosphates / biosynthesis
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Indole-3-Glycerol-Phosphate Synthase / genetics*
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Indole-3-Glycerol-Phosphate Synthase / metabolism
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Indoles / metabolism*
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Molecular Sequence Data
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RNA, Messenger / metabolism
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Recombinant Fusion Proteins / genetics
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Recombinant Fusion Proteins / metabolism
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Spodoptera / metabolism
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Transcriptional Activation*
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Zea mays / enzymology*
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Zea mays / genetics
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alpha-Linolenic Acid / analogs & derivatives
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alpha-Linolenic Acid / metabolism*
Substances
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DNA, Plant
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Fatty Acids
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Glycerophosphates
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Indoles
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RNA, Messenger
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Recombinant Fusion Proteins
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volicitin
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alpha-Linolenic Acid
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Glutamine
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indoleglycerol phosphate
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indole
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Indole-3-Glycerol-Phosphate Synthase
Associated data
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GENBANK/AF271383
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GENBANK/AF271384