Involved in the photosynthetic reductive pentose phosphate pathway (Calvin-Benson cycle). Catalyzes the reduction of 1,3-diphosphoglycerate by NADPH (By similarity). D-glyceraldehyde 3-phosphate + NADP(+) + phosphate = (2R)-3-phospho-glyceroyl phosphate + H(+) + NADPH Carbohydrate biosynthesis; Calvin cycle. Tetramer of either four A chains (GAPDH 2) or two A and two B chains (GAPDH 1). Expressed in leaves and stems. Repressed by darkness and sucrose. Plants contain three types of GAPDH: NAD-dependent cytosolic forms which participate in glycolysis, NAD-dependent chloroplastic forms which participate in plastidic glycolysis and NADP-dependent chloroplastic forms which participate in the photosynthetic reductive pentose phosphate pathway (Calvin-Benson cycle). All the forms are encoded by distinct genes. Belongs to the glyceraldehyde-3-phosphate dehydrogenase family.