Ca transporters are essential for pollen tube growth. Such events are essential for regulating the velocity and direction of pollen tube growth. The sperm cells are carried to their destination in the tip of the pollen tube. Pollen germination has three stages; hydration, activation and pollen tube emergence. The vegetative cell is responsible for pollen tube development. The length of the pollen tube varies by species. The actin cytoskeleton has proven to be critical in assisting pollen tube growth. In gymnosperms like "Ginkgo biloba" and cycadophyta, a haustorial pollen tube forms. The ovary releases chemicals that stimulates a positive chemotropic response from the developing pollen tube. This forms a nutrient rich tract for pollen tube growth. The shank region comprises the central part of the pollen tube. Therefore, this shows that RMD is localized within the tip of the pollen tube. Therefore, these results support that RMD is involved in pollen germination and pollen tube growth. Germination and growth of the pollen tube involve molecular signaling between stigma and pollen. During germination, the tube cell elongates into a pollen tube.