Quantitative short‐term uptake of inorganic phosphate by the Chara hispida rhizoid
Abstract The rhizoid of Chara hispida L. made a small contribution to the uptake of inorganic phosphate under laboratory conditions. At 1 mmol m−3 phosphate the rhizoid contributed about 4% to the uptake of the whole plant over 4 h. Under these conditions about half of the phosphate taken up by the rhizoid was translocated into the shoot. The rates of uptake and translocation increased with increasing external phosphate concentrations. 
 
When the shoot was in darkness, 32P-translocation from the rhizoid was less than half of that found when the shoot was illuminated. When the rhizoid medium was anaerobic the translocation rate was lower than the rate in aerobic conditions and illumination of the shoot had no effect on the uptake or translocation of phosphate. 
 
Translocated 32P accumulated in the apical growing regions of the plant. This was first noted in the secondary apices nearest to the rhizoids.