LAUSR

The pollen tube is a cellular cylindrical apical growing protuberance formed by the pollen grain upon contact with the stigma, the female organ of the flower [1]. The pollen tube’s main purpose is to ensure sexual reproduction in plants by delivering the sperm cells to the female gametophyte. To be able to accomplish this task, the elongating pollen tube has to emerge from the pollen grain by breaking through its thick wall and it has to penetrate the pistillar tissue without precociously bursting. Both situations require the loosening of cell wall material during germination the pollen intine proper has to yield and during pollen tube elongation the apoplast of the transmitting tract needs to be softened to allow for pollen tube passage [2-3].