title: Molecular analysis of poplar defense against herbivory: comparison of wound- and insect elicitor-induced gene expression.
abstract: In order to characterize defense responses of hybrid poplar (Populus trichocarpax P. deltoides), we profiled leaf transcript patterns elicited by wounding and by regurgitant from forest tent caterpillar (FTC; Malacosoma disstria), a Lepidopteran defoliator of poplars. Macroarrays were used to compare transcript profiles. Both FTC-regurgitant (FTC-R) and mechanical wounding with pliers elicited expression of a variety of genes, and for these genes our analysis indicated that these treatments induced qualitatively similar responses. Similarly, a comparison of responses of directly treated and systemically induced leaves indicated extensive overlap in the sets of induced genes. FTC-R was found to contain the insect-derived elicitor volicitin. The simulated herbivory treatments resulted in the induction of genes involved in poplar defense and secondary metabolism. We also identified wound-responsive genes with roles in primary metabolism, including a putative invertase, lipase, and acyl-activating enzyme; some of these genes may have roles in defense signaling. In addition, we found three unknown genes containing a ZIM motif which may represent novel transcription factors.
authors.affiliation: Centre for Forest Biology and Department of Biology, University of Victoria, Stn CSC, PO Box 3020, Victoria, BC, V8W 3 N5, Canada.
authors.forename: Ian T
authors.initials: IT
authors.lastname: Major
authors.forename: C Peter
authors.initials: CP
authors.lastname: Constabel
mesh_terms: D000818:Animals; D020224:Expressed Sequence Tags; D005247:Feeding Behavior / Q000502:physiology*; D015870:Gene Expression; D020869:Gene Expression Profiling; D017343:Genes, Plant; D007814:Larva / Q000502:physiology; D009036:Moths / Q000502:physiology*; D018515:Plant Leaves / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism*; D032107:Populus / Q000378:metabolism*; D014361:Trypsin Inhibitors / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D014361:Trypsin Inhibitors