Benzyladenine-induced Movement of C-Labeled Photosynthate into Roots of Vitis vinifera

Roots of Vitis vinifera L., were treated with benzyladenine when the plant shoots were 38 cm long. Seventy-two hours after benzyladenine treatment, apical or basal leaves on separate shoots were exposed to ¹⁴CO₂. Control shoots received ¹⁴CO₂ but no benzyladenine. Application of benzyladenine directed ¹⁴C-photosynthate to roots, but a small amount of radioactivity was detected in the shoot tip when ¹⁴CO₂ was administered to an apical leaf. Distribution of radioactivity among the sugar, organic acid, and amino acid fractions was altered by benzyladenine treatment. In all parts of plants with roots treated with benzyladenine and apical leaf fed ¹⁴CO₂, the percentage of the total label in the sugar fraction comprised of fructose was generally more than twice that in control plants.