Submitted to: Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 22, 2000
Publication Date: N/A
Interpretive Summary: Acquired thermotolerance is a complex physiological phenomenon that enables plants to survive normally lethal temperatures. Although the phenomenon has been described, the underlying mechanisms responsible for the induced protection remain a mystery. This study describes the analysis of wheat germplasm containing specific chromosomal deletions to determine if these deletions alters the natural protection system. The results of this study have allowed us to identify wheat lines with improved protection systems involved in the protection of plants from high temperature stress.
Technical Abstract: A study of the ditelosomic series of 'Chinese Spring' wheat has yielded a number of lines displaying either an increased or decreased ability to acquire thermotolerance. One such ditelosomic (DT) is termed DT1BS which refers to the missing short arm of chromosome 1 in the B genome. Relative to 'Chinese Spring', this line has the ability to acquire thermotolerance at lower induction temperatures and provide greater protection to the plan against elevated temperatures. Using a chlorophyll accumulation assay to measure plant health, we show that DT1BS accumulates chlorophyll optimally at the same temperature, and to similar levels as 'Chinese Spring'. We also show that maximum acquired thermotolerance against a 48C challenge is induced at 40C, but significant levels of protection can be obtained at temperatures as low as 34C in DT1BS or 36C in 'Chinese Spring'. Heat shock protein accumulation is observed in DT1BS at temperatures 4C lower than the e'Chinese Spring' and is correlated with the induction of acquired thermotolerance.