Gillham, E.; Hu, J.; Huang, Y.; Kochi, A.; McDonald, K.; Scott-Joseph, C.; Xu, C.; Ye, M.; Kaplinsky, N.

Thermal adaptation is critical for organismal viability, with acquired thermotolerance (AT) in Arabidopsis thaliana typically conferred by acclimation temperatures between 34{degrees}C and 37{degrees}C, while acclimation at 40{degrees}C fails to protect against lethal heat stress. To elucidate the transcriptional mechanisms underlying the loss of AT at higher temperatures we performed RNA-seq profiling of Arabidopsis seedlings across a single-degree thermal gradient from 37{degrees}C to 40{degrees}C. Our analysis reveals that all of these temperatures result in a robust heat shock response, characterized by the upregulation of genes involved in protein folding and stress responses. However, each temperature elicits a distinct transcriptional signature. These findings demonstrate that temperature-specific fine-tuning of the heat shock response occurs within this narrow range and that these differences may dictate the successful acquisition of thermotolerance. This dataset provides a valuable resource for understanding the molecular architecture of heat-stress adaptation and the distinct transcriptional states associated with different thermal regimes.