Hydrolysis and resynthesis of sucrose and related sugars in the developing stem tissues of Eucalyptus regnans trees.

When cambial tissues are removed from tree stems of Eucalyptus regnans F. Muell. and incubated in vitro with [(14)C]glucose, [(14)C]galactose and [(14)C]fructose in the presence of sufficient PVP (polyvinylpyrrolidone) radioactive sucrose, members of the raffinose family and related sugars are synthesized. These results suggest that PVP inactivates substances which, in in vitro experiments, inhibit the action of enzymes which are essential to the resynthesis of nutrient sugars (sucrose, raffinose and stachyose). In living trees, such enzyme inhibition is less likely to occur.