Intracellular Microfluid Transportation in Fast Growing Pollen Tubes

Fast tip growth of pollen tubes is a process of fundamental importance in sexual plant reproduction. In this chapter, physical models were developed to analyze the hydrodynamics and the advection-diffusion dynamics of fountain streaming in pollen tubes. It is demonstrated that the unique properties of fountain streaming contribute to the fast tip growth of pollen tubes by regulating the gradients of turgor pressure and cell wall materials. Simple experiments confirm that the tip shape and growth rate of pollen tubes are influenced by the changes in turgor pressure gradients as induced by drought stress. Both the analytical and the numerical methods presented in this chapter provide mechanistic insights for the understanding of the sexual reproduction and infertility of flowering plants under normal conditions and drought stress.