Mechanism of axis formation during zygote development in rice

Abstract

The first division of the fertilized egg is the earliest asymmetric division in many angiosperms and is considered an important process that gives rise to morphologically and functionally differentiated apical and basal cells. The process of zygote development has been analyzed in detail using Arabidopsis thaliana, a model dicotyledonous plant, and the relationship between cell asymmetric division and somatic axis formation has been demonstrated. In contrast, information on fertilized egg polarity in other angiosperms is limited, and the molecular mechanisms involved in body axis formation are largely unknown. Since fertilization and embryogenesis of angiosperms occur in the embryo sac, it has been challenging to observe the developmental process of fertilized eggs. In this review, we review the knowledge about rice axis formation and introduce our recent approaches to the developmental process of fertilized eggs using in vivo and in vitro imaging.