Ozone stress Transcriptomics in Viburnum lanata. Ozone Stress Viburnum

In the present study, we report the characterization of the transcripts expressed in the shrub species Viburnum lantana L. (Wayfaring Tree) during treatment with ozone (60 ppb for 45 days, 5 hours per day). Suppression subtractive hybridization (SSH) was used with the aim to assess the biological relevance of the ozone treatment on the induced (I) and repressed (R) libraries, in order to present an overview of the effect of ozone at the biological, cellular and molecular level and to reveal the differences in the expression of the transcripts during the ozone exposure. A total of 38,800 and 12,495 high quality reads were obtained using SSH and 454-pyrosequencing, representing a total of 1241 unigenes in Ensembl transcriptome. mRNA abundance was measured by reads per kilobase per million (RPKM), and over-expression of the transcripts with GO categories revealed involved in the defense against oxidative stress, glutathione (GSH) and thioredoxin-1 (Trx1). On the contrary, GO categories involved in carbon utilization and photosynthesis (light harvesting complexes) was found to be repressed in ozone exposed plants suggesting the activation of the enriched GO terms as a molecular defense of the plant metabolic machinery to ozone response. Functional ontological analysis revealed several important stress related categories and expression differences in the induced and repressed libraries showed couple of transcripts demonstrating up- and down-regulation linked with several important biological functions.