Plays pivotal roles in chloroplast development. Is essential for the regulation of chloroplast development and differentiation. Interacts with PCNA. Expressed in roots, stems, leaves and panicles. Induced by UV and hydrogen peroxide. Down-regulated during sucrose starvation. Transiently down-regulated by heat shock. Plants silencing DJA7 exhibit albino lethal phenotypes, display abnormal cellular structures, organelles and chloroplasts, and strong reduction of the expression of CAB1R, CAB2R, PsaA and PsbA genes, tightly associated with chloroplast development. Belongs to the DnaJ family.