The rice transcription factors OsICE confer enhanced cold tolerance in transgenic Arabidopsis

ABSTRACTCold stress is one of the major constraints for crop yield. Plants have in turn evolved highly sophisticated mechanisms involving altered physiologic and biochemical processes to cope with the cold stress. Previous studies have revealed that the INDUCER OF CBF EXPRESSION 1 (ICE1), a basic helix-loop-helix (bHLH) transcription factor, directly binds and activates the expression of C-Repeat Binding Factor/Dehydration-Responsive-Element-Binding protein (CBF/DREB1) to regulate the cold-response pathway in Arabidopsis thaliana. However, the function of AtICE1 orthologues in rice is largely unknown. Here we identified that OsICE1 and OsICE2 in rice shared highly conserved amino acid sequence with AtICE1 in Arabidopsis. Overexpression of OsICE1 and OsICE2 in Arabidopsis significantly enhanced the cold tolerance of Arabidopsis seedlings and improved the expression of cold-response genes. Furthermore, we showed that both OsICE1 and OsICE2 physically interact with OsMYBS3, a single DNA-binding repeat MYB tr...