Submitted to: Plant Physiology
Publication Type: Abstract Only
Publication Acceptance Date: July 16, 2000
Publication Date: N/A
Technical Abstract: The temperature sensitivity of chlorophyll accumulation has been used to identify acquired thermotolerance in higher plants. This study describes the initial characterization of an acquired thermotolerance mutant AtTS300 of Arabidopsis thaliana. This acquired thermotolerance mutant was selected by screening a M2 population of Columbia Arabidopsis thaliana seedlings derived from seeds treated with the mutagen ethyl methane sulfonate. Etiolated Columbia seedlings preincubated at 38 C for 4 h to induce thermotolerance and then challenged at 44 C for 30 min in the dark turned green within 24 h when exposed to continuous light. The AtTS300 mutant seedlings are light green within 24 h, but attain full Chl levels within 72 h. This delayed pattern of chlorophyll accumulation was observed in control Columbia seedlings that had not been exposed to the 38 C preincubation. Analysis of the M8 population of seedlings derived from the acquired thermotolerance mutant revealed severely reduced protection levels compare with control Columbia seedlings. Genetic analysis showed that the loss of acquired thermotolerance in AtTS300 was a recessive trait.