|Ohm, Herbert - PURDUE UNIVERSITY|
|Lohret, T - CURAGEN CORP|
|Crasta, O - CURAGEN CORP|
Submitted to: Entomological Society of America Regional Meetings
Publication Type: Abstract Only
Publication Acceptance Date: November 15, 2002
Publication Date: March 23, 2003
Citation: Williams, C.E., Goodwin, S.B., Ohm, H.W., Anderson, J.M., Crane, C.F., Scofield, S.R., Lohret, T.A., Crasta, O.R. 2003. Transcription profiling of wheat defense responses: hessian fly versus microbial pathogens. In: Proceedings of the Entomological Society of America Regional Meetings. Entomological Society of American-North Central Branch, March 23-26, 2003, Madison, Wisconsin. Available: http://esa.ent.iastate.edu/confreg/?gridaction=viewonepresentation&year=2003 &presnum=083 Technical Abstract: Many genes conferring resistance to diverse pests and pathogens have been identified in wheat. However, the molecular mechanisms of plant defense are not well enough defined to determine whether resistance occurs by shared or by pathogen-specific pathways. To identify wheat genes responding to biotic stress, plants were treated with pathogens and analyzed by GeneCalling®, an open-architecture transcript profiling technology that leads to the quantification of differentially expressed sequences (www.curagen.com). Wheat plants were challenged with Mayetiola destructor (Hessian fly), Mycosphaerella graminicola (cause of septoria tritici leaf blotch), Fusarium graminearum (cause of head scab), and Barley Yellow Dwarf Virus. The GeneCalling experiments profiled >12,000 cDNA fragments per sample and detected a large number that were differentially modulated by at least 1.5 times in each treatment. For example, in the Hessian fly-infested tissue, both compatible and incompatible interactions were monitored over the first 72 hr following egg hatch, yielding 115 cDNA fragments that were differentially modulated in at least one time-point. Sequencing and BLAST analysis of 685 fragments, taken from all treatments, revealed many genes known to be activated during defense responses in dicots, including phenylalanine ammonia lyase, glucanases, chitinases, peroxidases, and thaumatin-like proteins. Numerous additional genes appeared to be involved in cell signaling, including kinases and phosphatases. Approximately 10% of the sequences had no matches in the six databases searched and may represent previously unknown mechanisms of resistance. These analyses revealed rapid resistance responses in wheat that utilize common pathways as well as unique genes that vary according to the insect or pathogen encountered.