Genome Responses Involved in Transitory Thermotolerance

Plants have evolved mechanisms that allow them to monitor their environment and respond to changes by altering several cellular and physiological processes. One of these response mechanisms is the ability of plants to acclimate rapidly to high temperatures. Acquisition of this temporary thermotolerance usually results from short pretreatment or brief exposure to sub-lethal temperatures. Scientists from the University of Arizona monitored the gene expression of acclimated Arabidopsis plants to identify molecular events important for acquired thermotolerance.

The scientists identified eight new genes involved in heat acclimation, including genes coding for enzymes that limit oxidative stress and heat shock proteins (molecules that protect proteins from denaturation). Genes involved in programmed cell death, basic metabolism and biotic stress response were down-regulated. Accumulation of proline, an amino acid toxic at elevated temperatures, was also inhibited.

The abstract of the paper is available at http://www.plantphysiol.org/cgi/content/abstract/146/2/748 The full text is available to subscribers at http://www.plantphysiol.org/cgi/reprint/146/2/748