Involved in the initial differentiation of the proplastid during the embryo development and in plastid differentiation linked to cell differentiation, morphogenesis and organogenesis during the plant life cycle. Interacts with EMB506. No homodimerization observed. Expressed mainly in chloroplast-containing tissues. Also detected in roots, stems, flower buds, developing siliques and dry seeds. Highest expression occurs in four-day-old plants and declines as plants develop further. By light. Plants show a developmental arrest of the embryos at the globular stage. Found predominantly in leaves and inflorescence stems. Found predominantly in flower buds and siliques. Seems to be unable to interact with EMB506.