Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: May 20, 2004
Publication Date: July 20, 2004
Citation: Okubara, P.A., Skinner, D.Z. 2004. Microarray expression profiles of wheat roots and shoots during cold stress and root colonization by biocontrol pseudomonas fluorescens. American Society of Plant Biologists Annual Meeting. Plant Biology 2004, Abstract No. 694. Technical Abstract: Crop plant varieties having tolerance to multiple stresses are valuable in the face of the changing environment, growth habitat, and natural resources. In the Pacific Northwest (PNW), Triticum aestivum (hexaploid wheat) must be able to survive freezing temperatures and absence of irrigation. In addition, wheat roots are challenged by necrotrophic pathogens, including Pythium, Rhizoctonia, and Fusarium, for which there is no effective resistance. Biological control strains of Pseudomonas fluorescens provide a measure of control for some of these pathogens. The goals of this research are to characterize signal pathways that operate in wheat roots, and to determine if the activation of stress signal pathways by acute cold temperature imparts tolerance to a second stress, such as pathogen challenge or rhizosphere colonization by P. fluorescens. We identified over 100 wheat sequences encoding stress/defense homologs from root expressed sequence tags (ESTs) generated by the National Science Foundation Wheat EST Genomics Project, and from TIGR virtual EST contigs. Oligonucleotides (60mer) representing these expressed genes have been generated using a novel software program. In an initial 47-gene array, we identified root and shoot mRNAs that are co-regulated or differentially regulated by acute cold stress and rhizosphere colonization by P. fluorescens strain Q8r1-96. Results of an expanded array and implications of signal pathway intersection will be discussed.