Metabolism of Myo-Inositol and Growth in Various Sugars of Suspension cultured Tobacco Cells

Abstract

Tobacco (Nicotiana tabacum L.) cells were cultured in a liquid medium which contained sucrose as a source of carbon and energy. Various cell-wall constituents and wall precursors (Larabinose, D-xylose, D-galactose, D-mannose, D-glucuronate, myo-inositol) were added to cells growing in this medium to by-pass possible rate-limiting steps in the relevant metabolic pathways. None of these compounds stimulated growth as measured by increase in fresh weight; myo-inositol did cause a slight increase and L-arabinose a decrease in dry weight accumulation compared to controls grown on sucrose only. Although myo-inositol was not needed for rapid growth, tracer level amounts of [2-3H]myo-inositol were rapidly absorbed and metabolized. Label was incorporated into the uronide and pentose residues of cell walls and exocellular polysaccharide.