In angiosperms, the fertilization between female and male gametes is unique when compares to other species. Angiosperms' sperm cell which has no autonomous mobility needs pollen tube to be delivered to female gamete. When pollen tubes grow in pistil, there are complex communication systems between male and female to regulate pollen tubes target to female gametophytes. Ovules secret pollen tube attractants, and pollen tubes respond to those signals, ovules and pollen tubes work together to make sure that pollen tubes are targeted to the micropylar of the embryo sac. Our interest is finding the pollen tube guidance mechanism.