, was also induced by DMSO treatments and decreased by BA pretreatments these data indicate that membrane rigidification occurs upstream of MEKK1 -MKK2-MPK4 cascade during cold acclimation. The cold- inducible gene,COR15a, was expressed by DMSO without cold treatment, whereas its expression was suppressed by the BA pretreatment. Moreover, we determined that the DMSO-treated seedlings acquired freezing tolerance without cold acclimation, and the