Submitted to: Plant and Animal Genome Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: September 26, 2006
Publication Date: January 13, 2007
Citation: Dinkins, R.D. 2007. Microarray Comparison of Endophyte-Infected and Endophyte-Free Tall Fescue. Plant and Animal Genome XV Conference Proceedings. 676:Other Species. Technical Abstract: Many grasses have mutualistic symbioses with fungi of the family Clavicipitaceae: Tall fescue (Festuca arudinacea = Lolium arundinaceum) can harbor the obligate endophyte, Neotyphodium coenophialum that are asexually propagated and transmitted via host seeds. In an effort to begin to dissect the host plant endophyte cross-talk, global gene expression was analyzed using the Affymetrix Wheat Genome Array GeneChip® and Barley 1 Genome Array GeneChip®. Total RNA was isolated from pseudostems of known endophyte-infected and endophyte-free plants and tested in triplicate. Overall only 14-15% and 17-18% of the probe sets were called present on the wheat and barley chips, respectively. These results are somewhat lower than expected based on the relatedness between fescue, wheat and barley. However, a number of probed sets were observed to be differentially expressed greater than two-fold (P<0.01) between the endophyte-infected and endophyte-free plants. PCR primers were designed to a number of fescue EST's with homology to sequences on the GeneChip arrays and tested to verify the expression profile observed in the microarray experiments. Some primers gave results similar to the expected, although in other cases no differences were observed between the endophyte-infected and endophyte-free or the results were contrary to what was expected. It is unknown whether the primers that did not give expected results are indicative of the particular gene or allele that was used for primer design compared to what was detected on the array. Additional primers are being synthesized based on wheat and barley sequences from the arrays to verify the results.