Expression Levels of Heat Tolerance Associated Genes in Bentgrasses.

Heat is a major abiotic stress which can lead to premature senescence and a major decline in overall quality in perennial bentgrass species. Understanding the effects of heat stress and the mechanisms for heat tolerance will be of key importance for creating plants with improved heat tolerance. Previous studies have found several genes or their associated proteins which may play important roles effecting heat tolerance. Important tolerance related functional categories previously identified to exhibit changes during heat stress include energy production, metabolism and defense/protection. To confirm the potential importance of these candidate genes for heat tolerance, their expression levels were measured using real-time PCR. Two lines from a creeping colonial bentgrass hybrid mapping population, previously show to have significant variation in heat tolerance, were compared. To induce heat stress plants were maintained in a growth chamber with 35/30 C day/night temperatures, and maintained well watered. Tissue samples of the same development age were collected at 2, 10 and 18 days heat stress and then used to look at the expression levels of several potentially important genes. Comparing a sensitive line with a tolerant line will help identify expression changes that are not only associated with the onset of heat stress but also the genes which play a role in the tolerant line’s ability to maintain higher quality throughout the stress period.