Gene expression profiling of potato responses to cold, heat, and salt stress.

In order to identify genes involved in abiotic stress responses in potato, seedlings were grown under controlled conditions and subjected to cold (4 degrees C), heat (35 degrees C), or salt (100 mM NaCl) stress for up to 27 h. Using an approximately 12,000 clone potato cDNA microarray, expression profiles were captured at three time points following initiation of the stress (3, 9, and 27 h) from two different tissues, roots and leaves. A total of 3,314 clones could be identified as significantly up- or down-regulated in response to at least one stress condition. The genes represented by these clones encode transcription factors, signal transduction factors, and heat-shock proteins which have been associated with abiotic stress responses in Arabidopsis and rice, suggesting similar response pathways function in potato. These stress-regulated clones could be separated into either stress-specific or shared-response clones, suggesting the existence of general response pathways as well as more stress-specific pathways. In addition, we identified expression profiles which are indicative for the type of stress applied to the plants.