W014 Extent and Characterization of the Arabidopsis Defense Transcriptome Regulated at the Transcript Isoform Level

Date: Sunday, January 15, 2012
Time: 4:15 PM
Room: Royal Palm Salon 1-2
Paola Veronese , North Carolina State University, Raleigh, NC
The latest annotation of the genome of model plant Arabidopsis thaliana (Tair10, Nov 2010) showed that 5,886 genes (~18% of the total genes, referred to as AS genes) generate multiple transcript isoforms mostly via alternative transcriptional starting sites (TSS) and/or alternative splicing. To contribute to establish a possible functional significance for differential alternative transcript accumulation during stress exposure, we characterized the Arabidopsis defense transcriptome via RNA-Seq experiments. In particular, we generated Illumina 75bp paired-end reads from samples challenged with virulent and avirulent strains of the bacterial phytopathogen Pseudomonas syringae pv tomato (Pst) and estimated differences in the transcript isoform abundance by using the open source software program Cufflinks. We found that about 5 and 7% of the detected AS genes were characterized by regulated expression of two or more of the corresponding alternative transcripts during susceptible and resistant response, respectively. While numerous of the Pst–responsive AS genes have established key roles in plant stress biology, for most of these genes this is the first report linking the function they exert in plant protection with the regulation of individual transcript isoforms.