Immunolocalization of proteins in somatic embryos: applications for studies on the cytoskeleton

Plant embryogenesis requires a tight balance between cell proliferation and differentiation. In animals, embryogenesis is dependent on cell migrations, which is in contrast to plant embryogenesis where the rigid cell wall precludes migration. Therefore, plants have to position cells correctly by defining the direction of the division plane during proliferation and control cell shape by local cell expansion. Both these processes are reliant on the organization and dynamics of the cytoskeleton-actin filaments and microtubules. In previous work (7), we have shown that differentiation of the embryo suspensor is accompanied by reorientation of microtubules from random to transverse and reorganization of actin filaments from a fine filamentous network to bundled longitudinal cables. Here, we describe the technique for visualization of cytoskeletal components including actin filaments, microtubules and their associated proteins during the development of plant embryos in whole-mount specimens.