Effect of Benzyladenine, 2,4-Dichlorophenoxyacetic Acid, and d-Glucose on myo-Inositol Metabolism in Acer pseudoplatanus L. Cells Grown in Suspension Culture

Suspension cultures of Acer pseudoplatanus L. cells grown for 15 days in medium (T. Murashige and F. Skoog. 1962. Physiol. Plant. 15: 473-497) contained 3% sucrose, 1 mg/l 6-benzylaminopurine (BA), and 0.1 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D), referred to here as normal media, removed newly added myo-inositol-2-(3)H up to 100 mg/l in 24 hours and utilized up to 20% of this cyclitol for pectin biosynthesis. When the BA content of the growth medium was raised 10-fold, uptake of myo-inositol was drastically reduced and very little was available for pectin biosynthesis. Neither cell growth as measured by packed cell volume or by dry weight, nor monomer composition of pectic polysaccharides was affected by the increased level of cytokinin. Increasing, 2,4-d 10-fold instead of BA had little or no effect on myo-inositol uptake, although it did reduce the amount of myo-inositol utilized for pectin biosynthesis. Cells grown 15 days in normal media failed to remove added myo-inositol if 3% d-glucose was included. The net result was similar to that found in cells grown in the high BA condition. If a trace amount of d-galactose-1-(14)C was supplied to cells after 15 days of growth in normal, high BA, or high 2,4-d media, there was no significant variation in uptake and utilization of label among the three growth conditions.