ARS | Publication request: Functional Roles of FtsH11 in Thermotolerance and Photosynthetic Stress in Plants

Submitted to: Gordon Research Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: January 21, 2007
Publication Date: January 26, 2007
Citation: Chen, J., Velten, J.P., Burke, J.J. 2007. Functional Roles of FtsH11 in Thermotolerance and Photosynthetic Stress in Plants[abstract]. Gordon Ressearch Conference: Temperature Stress in Plants. Ventura, California. January 21-26, 2007.

Technical Abstract: FtsH11 protease was identified through map-based cloning to be essential for thermotolerance in Arabidopsis. Mutations within this gene produce plants sensitive to moderately high temperatures (at or above 30°C) and render the mutant plants unable to acquire thermotolerance. The unique contribution of FtsH11 to thermotolerance sets it apart from all other previously characterized Arabidopsis FtsH proteases which function exclusively to alleviate damage due to high light exposure. Upon exposure to 30oC, a mild thermal stress for Arabidopsis, the photosynthetic capability of ftsh11 mutants is greatly reduced. Prolonged exposure at or above this temperature results in cessation of plant growth and development, and eventually death. Overexpression of wild-type ftsh11 was found to complement the thermosensitive phenotypes of ftsh11 mutants. However, excessive production of FtsH11 using the strong CaMV35 promoter also caused an assortment of variegated leaf phenotypes in transgenic plants grown at normal temperature. Further analysis has indicated that FtsH11plays roles in the early stages of chloroplast biogenesis and the thermostability of photosynthetic systems. Our results suggest that not only is FtsH11 essential to thermotolerance in Arabidopsis, but the abundance and activity of this protease, and possibly its cellular distribution, are tightly regulated.