Abstract
Double fertilization is a one of the remarkable features in angiosperms. A pollen grain contains two sperm cells. One of the two sperm cells fertilizes the egg cell to produce embryo. Another sperm cell fertilizes the central cell to produce an endosperm which supplies nutrient to the embryo. The movement of the sperm cells during double fertilization was never caught before. Therefore, basic questions for double fertilization, such as what are paths of sperm cells to reach target female gametes and why two sperm cells can fertilize different partners are not resolved. In this decade, technical innovation of live-cell imaging has enabled to reveal the sperm cell movement during double fertilization. In this review, we discuss the double fertilization process from pollen tube discharge to gamete fusion, focusing on sperm cell movement by live-cell imaging and molecular genetic approaches.
