Submitted to: Keystone Symposia
Publication Type: Abstract Only
Publication Acceptance Date: April 8, 2006
Publication Date: April 13, 2006
Citation: Xin, Z., Chen, J. 2006. Allelic analysis of ESK1 gene[abstract]. Keystone Symposia: Plant Reponses to Abiotic Stress. Copper Mountain, Colorado. April 8-13, 2006. Technical Abstract: Many temperate plants acquire an increased freezing tolerance in response to a period of low nonfreezing temperatures through an adaptive process known as cold acclimation. Microarray and genetic studies indicate that multiple pathways act in concert to bring about increased freezing tolerance during cold acclimation. To study the various mechanisms plants have evolved to cope with freezing temperatures, we have carried out a genetic screen in Arabidopsis to isolate constitutively freezing tolerant mutants that bypass the requirement for the prior exposure to low nonfreezing temperatures. Nonacclimated wild-type Arabidopsis can survive freezing at -5.5ºC; a constitutively freezing tolerant mutant, esk1, survived 10ºC in the absence of cold acclimation. Transcriptome analysis in a missense allele and a T-DNA tagged KO allele of the esk1 mutants revealed that the freezing tolerance activated in esk1 mutants was independent of the induction of CBF-regulon. Positional cloning of ESK1 gene uncovered a large family of plant-specific proteins whose function has not been previously characterized. None of the ESK1-family proteins contains a characterized domain. To identify the protein domains that are critical to ESK1 function, we have isolated 26 mis-sense mutant alleles of ESK1 locus through Arabidopsis TILLING Project at University of Washington. Physiological characterization of these alleles identified several conserved domains that are essential to the function of ESK1 protein.