Required for double fertilization of the egg cell and the central cell by two sperm cells, resulting in the formation of the embryo and the endosperm (PubMed:22872756, PubMed:17965055). Involved in the regulation of embryonic expression of PHE1 (PubMed:17965055). Essential in maternal tissues to ensure the paternal embryonic expression of several genes, including RPS5a and FAC1, both of which being essential for early embryo and endosperm development in fertilized seeds (PubMed:17965055). Restricted to the central cells of embryo sacs. Observed throughout the embryo sac and in sporophytic tissues including the funiculus and the placenta. In the embryo sac, confined to synergid cells (SCs) (PubMed:22872756). Observed in sporophytic tissues including the micropylar end of integuments and placenta (PubMed:22872756). Female gametophytic mutant which exhibits embryo development without any endosperm due to a successful sperm cell fusion with the egg cell but an impaired fusion of the second sperm cell with the central cell, thus resulting in single fertilization (PubMed:22872756, PubMed:17965055). Embryos can develop up to the globular stage in the absence of endosperm (PubMed:17965055). Belongs to the plant acyltransferase family.