May play a role in leaf development. Required for leaf mesophyll cell division in the early stages of leaf organogenesis. Expressed in root meristem, root vasculature, distal region of young leaf primordia, leaf bundle sheath cells, hydathodes and pollen grains. During embryo development, expressed from the heart stage onwards and restricted to the adaxial side of the cotyledons in mature embryos. Defects in embryo development, seedling germination and early growth. Pale interveinal phenotype due to marked reduction in the density of mesophyll cells in interveinal regions of leaves. Belongs to the RETICULATA family.