Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: 1/14/2006
Publication Date: 1/18/2006
Citation: Chen, J., Burke, J.J., Velten, J.P., Xin, Z. 2006. Ftsh11 is essential to thermotolerance in arabidopsis. Plant and Animal Genome Conference. P. 405 XIV Conference.
Technical Abstract: Elevated temperature is a constant environmental stress limiting plant growth and development. Several Arabidopsis thaliana thermo-sensitive mutants (atts) were isolated using chlorophyll accumulation assay following a sub-lethal heat treatment of dark grown, 2-d-old seedlings at 38ºC. The gene defined by the atts244 mutant was identified through map-based cloning. The gene encodes a nuclear encoded, chloroplast targeted FtsH protease, FtsH11. Another mutant allele of the FtsH11 gene and a T-DNA tagged knockout allele identified from the Salk T-DNA Express (http://signal.salk.edu/cgi-bin/tdnaexpress) displayed the identical thermosensitive phenotype as the atts244 mutant. The Arabidopsis genome has 12 predicted FtsH proteases. All the previously characterized FtsH proteases, FtsH1, FtsH2, FtsH5 and FtsH8, play an exclusive role in photoinhibition and light induced turnover of photosystem II D1 protein. However, unlike FtsH 1, FtsH2, FtsH5 and FtsH8, our study indicates that FtsH11 plays an important role in high temperature stress tolerance instead of tolerance to light stress. Disruption of the FtsH11 gene reduced the basal thermotolerance in mutants and rendered the mutant plants unable to acquire thermotolerance. The photosynthetic capability in mutant plants was greatly reduced when they were exposed to a moderately high temperature of 31oC but was not affected by light stress. Our results suggest that FtsH11 is essential to thermotolerance in Arabidopsis.