The impact of cold priming on the light and cold regulation of gene expression in Arabidopsis thaliana

We analysed the effect of cold priming on cold and high light regulation of gene expression. 5 days after the first cold treatment the primary stress response was widely reset. Then, a second (triggering) cold stimulus (24 h 4 °C) and a triggering high-light stimulus (2 h 800 µmol quanta m-2 s-1), which regulate many stress responsive genes in the same direction in naïve plants, caused widely specific and even inverse regulation of priming-responsive genes. Overall design: Transcript levels were assessed in a transcriptome wide scale by single end next generation sequencing (Illumina High-Seq4000). Half of the 4-week old Arabidopsis thaliana Col-0 plants were primed for 24 hours at 4 °C. 5 days after priming, 1/3 of the non-primed and 1/3 of the cold-primed plants were harvested before triggering (non-primed control plants = C, primed plants = P). Half of the remaining primed and half of the remaining cold-primed plants were cold triggering for 24 hours at 4 °C (cold primed + cold triggered = PT-C; only cold trigger = T-C). The other plants were exposed for two hours at 800 µmol quanta*m-2 s-1 (cold primed + light triggered = PT-L ; only light trigger = T-L), which similarly induces the cold-primable gene ZAT10 in naïve plants. Triggered plants were harvested 2 h after the end of the triggering treatment.