Sulfenylation of ENOLASE2 facilitates H2O2-conferred freezing tolerance in Arabidopsis.

H 2 O 2 affects the expression of genes that are involved in plant responses to diverse environmental stresses; however, the underlying mechanisms remain elusive. Here, we demonstrate that H 2 O 2 enhances plant freezing tolerance through its effect on a protein product of low expression of osmotically responsive genes2 (LOS2). LOS2 is translated into a major product, cytosolic enolase2 (ENO2), and sometimes an alternative product, the transcription repressor c-Myc-binding protein (MBP-1). ENO2, but not MBP-1, promotes cold tolerance by binding the promoter of C-repeat/DRE binding factor1 (CBF1), a central transcription factor in plant cold signaling, thus activating its expression. Overexpression of CBF1 restores freezing sensitivity of a LOS2 loss-of-function mutant. Furthermore, cold-induced H 2 O 2 increases nuclear import and transcriptional binding activity of ENO2 by sulfenylating cysteine 408 and thereby promotes its oligomerization. Collectively, our results illustrate how H 2 O 2 activates plant cold responses by sulfenylating ENO2 and promoting its oligomerization, leading to enhanced nuclear translocation and transcriptional activation of CBF1. [Display omitted] • H 2 O 2 confers plant freezing tolerance under cold-acclimated conditions • ENO2 promotes plant cold response by binding to and activating CBF1 • H 2 O 2 sulfenylation at ENO2 Cys408 is involved in plant freezing tolerance • Cold-induced H 2 O 2 triggers ENO2 oligomerization and nuclear import Liu et al. examine the role of H 2 O 2 in the plant cold response. They find that H 2 O 2 , through sulfenylation that promotes the oligomerization of ENO2, enhances ENO2 nuclear translocation and transcriptional binding activity. ENO2 in turn upregulates the expression of the cold response regulator CBF1 , thus promoting freezing tolerance. [ABSTRACT FROM AUTHOR]