Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: 12/1/2006
Publication Date: 1/17/2007
Citation: Clough, S.J. 2007. Cross comparing gene expression profiles of nodulation and pathogen infection. Plant and Animal Genome XV Conference. p. 91.
Technical Abstract: Symbiotic microbes must evade the host defense response as they penetrate plant tissue and establish symbiosis. Bradyrhizobium japonicum successfully penetrates soybean root hairs and cortical cells to establish nitrogen fixing nodules. We have been using Affymetrix and cDNA soybean microarrays to obtain the gene expression profiles of soybean root hair and whole root to B. japonicum infection. Additionally, we are cross comparing genes of these symbiosis expression profiles to expression profiles of soybean responding to various pathogens including Pseudomonas syringae, Sclerotinia sclerotiorum, Fusarium solani, and soybean mosaic virus. Gene expression data from these studies indicate that numerous defense related genes are initially up in abundance in root hairs at 3 hours post inoculation (hpi) and then are dramatically reduced by 6 hpi. Presumably these defense genes are involved in the early detection and effective defense response to pathogens, and B. japonicum actively repressed them to enable successful colonization. Further details of soybean response to pathogens compared to B. japonicum will be discussed.