Cytoplasmic streaming does not drive intercellular passage in staminal hairs ofSetcreasea purpurea

Summary The effect of inhibition of cytoplasmic streaming on intercellular passage of carboxyfluorescein (CF) in staminal hairs ofS. purpurea was examined. Tip cells of staminal hairs were microinjected with buffered-CF. Cytoplasmic streaming was then inhibited by addition of KCN or NaN₃ to the external bathing solution. In separate experiments, cytoplasmic streaming was inhibited by microinjection of cytochalasin D along with the buffered-CF. CF passage over a 5 minutes treatment period was monitored by video fluorescence microscopy and video intensity analysis. Cytoplasmic streaming ceased within 1 minute of inhibitor agent treatment, however, little change in the kinetics of intercellular passage was noted over the 5 minute experimental period. Th us, cytoplasmic streaming plays no major role in the regulation of intercellular passage of the hydrophilic, negatively charged molecule CF.The work is dedicated to professor Saal Zalik, Department of Plant Science, University of Alberta, on his 65th birthday.