EXCHANGE OF PROTEIN MOLECULES THROUGH CONNECTIONS BETWEEN HIGHER-PLANT PLASTIDS

Individual plastids of vascular plants have generally been considered to be discrete autonomous entities that do not directly communicate wi th each other. However, in transgenic plants in which the plastid stro ma was labeled with green fluorescent protein (GFP), thin tubular proj ections emanated from individual plastids and sometimes connected to o ther plastids. Flow of GFP between interconnected plastids could be ob served when a single plastid or an interconnecting plastid tubule was photobleached and the loss of green fluorescence by both plastids was seen. These tubules allow the exchange of molecules within an interpla stid communication system, which may facilitate the coordination of pl astid activities.