EN
A commercial anti-calmodulin monoclonal antibody (CaM MAb) was used to determine the presence and localization of calmodulin (CaM) and calmodulin-like protein in unpollinated and pollinated styles of Petunia hybrida. In the unpollinated style , CaM was localized in the cytoplasm of transmitting tract cells. The response to pollination and/or pollen tube growth was the presence of bound CaM-like protein in the extracellular matrix (ECM) of transmitting tissue. Gold particles were localized in the ECM surrounding the tips of the growing pollen tubes. In the pollen tubes, CaM epitopes were present mainly in and around some vesicles of the apical cytoplasm. The results suggest that CaM and CaM-like protein are involved in pollen tube growth in vivo.