The Uptake and Transport of14C in Cells ofConocephalum conicumL. in Light

Abstract

Dissolved inorganic ¹⁴carbon, fed to a small portion of the tissue of Conocephalun conicum, travelled along the tissues from cell to cell at rates of about 2.0 to 1.7 μm 5⁻¹, which is of the same order of magnitude as streaming rates in these cells. Trans-cellular transport can take place against a pressure gradient, but pressure gradients of 200 kPa or more in either direction reduced the trans-cellular transport significantly without reducing streaming rate and are, therefore, thought to have induced ‘valving’ effects at the plasmodesmata. Ammonium ion reduced or inhibited transport without reducing streaming rates and is, therefore, thought to have inhibited an active component in the plasmodesmata. Thus the results obtained from tandem cells of Nitella can be transferred to tissues.