title: Jasmonate and salicylate induce expression of herbivore cytochrome P450 genes.
abstract: Jasmonate and salicylate are plant-produced signals that activate plant defence genes after herbivory or pathogen attack. Amplification of these signals, evoked by either enemy attack or experimental manipulation, leads to an increase in the synthesis of toxic compounds (allelochemicals) and defence proteins in the plants. Although the jasmonate and salicylate signal cascades activate different sets of plant defence genes, or even act antagonistically, there is substantial communication between the pathways. Jasmonate and salicylate also contribute to protecting plants against herbivores by causing plants that experience insect damage to increase their production of volatile molecules that attract natural enemies of herbivorous insects. In response to plant defences, herbivores increase their production of enzymes that detoxify allelochemicals, including cytochrome P450s (refs 15, 16). But herbivores are potentially vulnerable to toxic allelochemicals in the duration between ingesting toxins and induction of detoxification systems. Here we show that the corn earworm Helicoverpa zea uses jasmonate and salicylate to activate four of its cytochrome P450 genes that are associated with detoxification either before or concomitantly with the biosynthesis of allelochemicals. This ability to 'eavesdrop' on plant defence signals protects H. zea against toxins produced by host plants.
authors.affiliation: Department of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China. lxc@life.uiuc.edu
authors.forename: Xianchun
authors.initials: X
authors.lastname: Li
authors.forename: Mary A
authors.initials: MA
authors.lastname: Schuler
authors.forename: May R
authors.initials: MR
authors.lastname: Berenbaum
mesh_terms: D000818:Animals; D000077102:Apium / Q000469:parasitology*; D003517:Cyclopentanes / Q000494:pharmacology*; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics*; D004789:Enzyme Activation; D004790:Enzyme Induction / Q000187:drug effects; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D017344:Genes, Insect / Q000235:genetics; D006790:Host-Parasite Interactions; D008658:Inactivation, Metabolic; D007915:Lepidoptera / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D054883:Oxylipins; D018515:Plant Leaves / Q000469:parasitology; D020156:Salicylic Acid / Q000494:pharmacology*; D015430:Weight Gain / Q000187:drug effects
chemical_list: D003517:Cyclopentanes; D054883:Oxylipins; C011006:jasmonic acid; D003577:Cytochrome P-450 Enzyme System; D020156:Salicylic Acid