Imaging elongating pollen tubes by green fluorescent protein

Abstract 

Pollen tube elongation is a dynamic process in which pollen tubes navigate and respond to female tissues to accomplish their mission of delivering the sperm cells for fertilization. The tube growth process itself is driven by regulated intracellular conditions that maintain the appropriate ionic environment, actin dynamics and a balance level of exocytosis and endocytosis to support growth at the tube apex. However, the interactive process within the pistil has not rendered itself accessible for direct observation. The contribution by individual cytosolic constituents of the pollen tube growth machinery remains to be determined. With the development of the green fluorescent protein reporter system, many of these questions can be addressed in live pollen tubes that elongate within the pistil and inchemically defined media. Analyses of the mechanisms that underlie pollen tube growth will be significantly facilitated.