Monday, November 13, 2006 - 8:00 AM
69-2
Heat-inducible Gene Expression Associated with Stress Tolerance in Agrostis species.
The objective of this study was to test whether a heat-induced gene in thermal Agrostis scabra can be used as a marker for selecting heat-tolerant creeping bentgrass cultivars. The heat-induced gene fragment was sequenced with the length of 646 bp and showed a high identity with the expansin gene in Schedonorus Pratensis with the identity of 93% and expect of 8e-19. Alignment was also conducted by its nucleotide sequence (blastn). There is a region of 552 bp highly related to the Festuca pratensis partial mRNA for expansin (exp2 gene) with the identity of 89% and expect of e-159. Genes encoding expansin proteins are important regulating stress tolerance. Eleven creeping bentgrass cultivars that vary in summer performance were selected for the initial screening test. Hybridization was conducted by probing the up-regulated gene from thermal species in the 11 creeping lines. The expansin gene fragment was found to be strongly up regulated during heat stress in the thermal species. The expression level varied with creeping bentgrass cultivars that differ in summer stress tolerance. The more tolerant cultivars, ‘Declaration’ and ‘Penn A-4’ had strongest expression of the expansin gene, while those ranked lower in summer rating such as ‘Putter’, ‘Kingpin’, ‘Century’, ‘Bengal’, ‘Backspin’, and ‘Pennlinks’ had weak or no expression. ‘Shark’, ‘L-93’, and ‘Independence’ that are ranked intermediate for summer performance showed intermediate level of expression.
Recorded presentation