الفهرس 
History of HSPsOnly 14 pages are availabe for public view
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Abstract
The problem of global warming is occupying the mind of many scientists lately. Dealing with this problem is taking place at different levels. However, for plant researchers the preparation to face this problem is through identifying cultivars which have the ability to grow under high temperatures. Many studies were conducted trying to understand more about the mechanisms of heat thermotolerance. These studies may enable us someday to produce safe and highly productive transgenic plants under the expecting heat stress. In the present study two different TTC reduction assays (as a function of dehydrogenase activity) and a membrane thermostability test were used to investigate the difference in the acquired thermtolerance among ten different wheat cultivars. The results proved that Siouxland and Sturdy are the most tolerant cultivars to heat while Sakha 69 and Giza 163 are the most sensitive ones. The next part of this work was done using SDS-pages electrophoresis and two dimensional gel electrophoresis techniques. Results showed that all the examined cultivars produce large numbers of HSPs in the ranges of 14- 18 kD, 20- 29 kD, 40-45 kD, and 70-80 kD. HSPs with higher molecular weight (HSPs100) were difficult to resolve. Siouxland (the first examined tolerant cultivar) was found to have five sHSPs in the range of 14- 18 kD and one HSP in the range of 70-80k more than Sakha 69 (the fnst examined sensitive cultivar). However, these differences were not found between the second examined tolerant (sturdy) and sensitive cultivars (Giza 163). At relatively high temperature (43•‹C) the tolerant cultivars were found to keep higher levels of all HSPs in the range of 20- 29 kD and one of the HSPs in the range of 70-80 kD than the sensitive ones.