Abstract
We have demonstrated that Arabidopsis SR proteins, atSR45a (plant-specific type SR protein) participates in a spliceosomal assembly through other splicing factors and its expression is markedly induced by high-light stress (Tanabe et al., 2009). These facts suggest that atSR45a is involved in the regulation of high-light stress responsive-alternative splicing events (AS). Here, to identify AS events of genes regulated by atSR45a, we compared gene expression profiles in the wild-type as well as the knockout atSR45a (KO-sr45a) plants under high-light stress using the tiling array.
The expression levels of 235 genome regions in the KO-sr45a plants were altered significantly compared with those in the wild-type plants. By semi-quantitative RT-PCR analysis, we confirmed changes in the transcript levels or AS patterns of the genes in response to high-light stress. In addition, temporal correlation between the expression levels of atSR45a and the AS efficiencies in these genes were observed in the progression of high-light stress. The sequencing analysis of the AS variants showed that atSR45a plays a principal role in switching of splicing in the intron retention events.
