During the reproductive process of flowering plants,the pollen tube acts as a transportation carrier for two sperm cells,interacts with various female tissues,delivers the sperm to the ovule,and achieves double fertilization.Successful fertilization relies on fine growth control of the pollen tube tip in female tissues.This includes maintenance of pollen tube integrity in the pistil transmitting tract and the timing of rupture of the pollen tube when it reaches the female ovule (Higashiyama,2018;Ge et al.,2019a).