Fertilization comprises a complex series of cellular processes leading to the fusion of a male and female gamete. Many studies have been carried out to investigate each step of fertilization in plants
however, our comprehensive understanding of all the sequential events during fertilization is still limited. This is largely due to difficulty in investigating events in the female gametophyte, which is deeply embedded in the maternal tissue. Recent advances in confocal microcopy assisted by fluorescent marker lines have contributed to visualizing subcellular dynamics in real time during fertilization in vivo. In this chapter, we describe a method focusing on the investigation of F-actin dynamics in the central cell during male gamete nuclear migration. This method also allows the study of a wide range of early sexual reproduction events, from pollen tube guidance to the early stage of seed development.