Stress-induced membrane protein that can bind heme and may play a role in the transport of tetrapyrrole intermediates during salt stress and contribute to the detoxification of highly reactive porphyrins in the cytoplasm. Localizes in chloroplast upon salt stress. Specifically expressed in seeds (at protein level). By abscisic acid (ABA) and osmotic and salt stresses (at protein level). Induced by methyl viologen. No visible phenotype under normal growth conditions. Plants overexpressing TSPO show increased sensitivity to ABA and salt stress. Cultured cells overexpressing TSPO have reduced greening and chlorophyll a content under light-growing conditions. Belongs to the TspO/BZRP family.