Molecular and genetic basis of freezing tolerance in crucifer species

 

Understanding genetic variation for freezing tolerance is important for unraveling an adaptative strategy of species and for finding out an effective way to improve crop productivity to unfavorable winter environments. The aim of this thesis was to examine natural variation for components of freezing tolerance beyond what has been done using the model organism Arabidopsis thaliana. Experiments using B. stricta were carried out to identify potentially novel and beneficial traits, and loci related to cold acclimation, or using a number of related Brassicaceae species were performed to understand mechanism for cold deacclimation. Our results strongly indicate differential regulatory mechanisms are involved in cold acclimation as well as cold deacclimation.Although we are still far from understanding those mechanisms, we have shown that exploiting natural variation using wild species provides new perspectives on ecologically important adaptation to cold, and may contribute to improve tolerance in crucifer species.