Positive regulator of abiotic stress tolerance involved in the regulation of plant growth. May be a downstream target of the abscisic acid (ABA) signaling pathway. Localizes to rod shaped ER structures that resemble ER bodies. Expressed in root tips, pericycle cells, lateral root primordia, stomata, leaf vasculature, hydathodes and floral organs. By salt and cold stresses, and abscisic acid. No visible phenotype under normal growth conditions, but mutant plant have enhanced sensitivity to salt, drought and cold stresses.