Transcriptional repressor involved in light acclimation, cold and oxidative stress responses. May regulate a collection of transcripts involved in response to high-light, cold and oxidative stress. Expressed in roots, stems and flowers. By H(2)O(2), cold, drought, cold or heat stresses, wounding, cucumber mosaic virus (CMV), exposure to high-intensity light and low-oxygen conditions in roots. No visible phenotype under normal growth condition, but enhanced tolerance to heat stress and increased sensitivity to salt stress. Plants overexpressing ZAT12 show thick and dark-green leaves with round shape, short petiole, elevated amounts of anthocyanins and enhanced tolerance to high-light irradiation and oxidative stress.