Plasmodesma 2001: on safari through the symplast.

Plant cells need to communicate with each other to orchestrate lifelong development, to integrate physiological processes, and to coordinate pathogen defense responses. The transmission of intercellular signals is an important means of regulating all plant life processes, from fertilization to senescence. In this framework, plasmodesmata (PD)— nanopores lined by plasma membrane that bridge the cytoplasm of most plant cells to their neighbors—play a pivotal role. PD function as relay stations in a unique cellular internet for the rapid exchange of water, metabolites, and even macromolecules. Exciting progress has been made in the field of plasmodesmal research, as reported at the 4th International Plasmodesma meeting in Cape Town, South Africa, in August 2001.