An Herbivore Elicitor Activates the Gene for Indole Emission in Maize

Proc Natl Acad Sci U S A. 2000 Dec 19;97(26):14801-6. doi: 10.1073/pnas.260499897.


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

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • DNA, Plant
  • Fatty Acids / metabolism*
  • Gene Expression Regulation, Enzymologic*
  • Gene Expression Regulation, Plant*
  • Genes, Plant
  • Glutamine / analogs & derivatives
  • Glutamine / metabolism*
  • Glycerophosphates / biosynthesis
  • Indole-3-Glycerol-Phosphate Synthase / genetics*
  • Indole-3-Glycerol-Phosphate Synthase / metabolism
  • Indoles / metabolism*
  • Molecular Sequence Data
  • RNA, Messenger / metabolism
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Spodoptera / metabolism
  • Transcriptional Activation*
  • Zea mays / enzymology*
  • Zea mays / genetics
  • alpha-Linolenic Acid / analogs & derivatives
  • alpha-Linolenic Acid / metabolism*


  • DNA, Plant
  • Fatty Acids
  • Glycerophosphates
  • Indoles
  • RNA, Messenger
  • Recombinant Fusion Proteins
  • volicitin
  • alpha-Linolenic Acid
  • Glutamine
  • indoleglycerol phosphate
  • indole
  • Indole-3-Glycerol-Phosphate Synthase

Associated data

  • GENBANK/AF271383
  • GENBANK/AF271384