P0808 Expression Analysis of Endophyte-Infected and Endophyte-Free Tall Fescue

Randy Dinkins , USDA-ARS-University of Kentucky, Lexington, KY
Padmaja Nagabhyru , University of Kentucky, Lexington, KY
Christopher Schardl , University of Kentucky, Lexington, KY
Molecular tools for forage grasses are presently sparse. A cDNA sequencing effort was conducted and roughly 140,000cDNA clones from normalized libraries obtained from Lolium pratense /Epichloe festucae inflorescences and stromata and Lolium arundinaceum roots assembled into 42,003 non-fungal unigenes. This assembly serves as the basis for plant genomic analysis and further molecular tool development in Lolium species.  The assembly was used to anchor sequencing done using the Next Generation Illumina  sequencing (RNA-Seq) comparing expression in pseudostems of clone pairs of tall fescue infected with Neotyphodium coenophialum (E+) with pseudostems of non-infected plants (E-). Of the 12 million Illumina reads approximately 60% of the reads matched 36,492 plant unigenes.  An additional 4 million reads matched de novo assembled contigs of the remaining reads. Comparison of the expression between the E+ and E- clone pairs found that 395 unigenes were differentially expressed two-fold or more.  RT-PCR verification of these differentially expressed genes is underway and will be presented.  The sequencing results demonstrated that specific Lolium unigenes are targeted, providing a molecular tool in the study of these important forage and turf grasses.