Changes in both gene expression and intron retention tune the Arabidopsis thaliana heat shock response.

Plant responses to high temperatures are critical for survival, yet acquired thermotolerance (AT) is limited to a tight temperature range. In Arabidopsis, 34 o C-37 o C induces AT while 40 o C does not. Analyzing RNA-seq data from seedlings acclimated between 37°C-40°C showed that while heat-induced genes are robustly expressed, their functional expression is severely attenuated as temperatures rise due to decreasing expression levels and increasing intron retention. This reduction, particularly for genes with functions in the heat shock response (HSR), suggests that combinatorial changes in expression and splicing play a key role in tuning the plant HSR and limiting AT at higher temperatures.