PREPARATION AND ASSAY OF CHALCONE SYNTHASE FROM WALNUT TREE TISSUE

Chalcone synthase activity was obtained from bark tissue of one-year-old shoots taken from a 30-year-old hybrid walnut tree Juglans nigra x J. regia. High tissue concentrations of phenolics, which are a major problem in woody plant enzyme extraction, were essentially overcome by the use of 200 mM ascorbic acid, 1.5% (w/v) polyethyleneglycol and 50 mM cysteine in the buffers, and a constant flow of nitrogen. Some properties of walnut tree chalcone synthase are discussed in comparison to those of the same enzyme from other plants.