Application of the disk method to cultured plant cells. II. Exhibition zones

Abstract

Growth inhibition of plated cells by antimetabolites present in the culture medium was alleviated by corresponding metabolites supplied on filter paper disks placed on the surface of the medium. The metabolites diffused into the medium producing a halo of growing cells (an exhibition zone). Exhibition zones were recorded for 15 pairs of compounds and with cell cultures of Rosa, Acer pseudoplatanus, Daucus carota, Hyoscyamus muticus and Zea mays. The interaction between the compounds could be quantified by measuring exhibition zone diameters and the method was partially optimised for L-ethionine/L-methionine and p-fluorophenylalanine/L-phenylalanine. The exhibition zone method was compared to two other methods, measurement of growth yield and plating efficiency, for demonstrating .reversion of growth inhibition. AbbreviationsETH = L-ethionine PFP = p-fluorophenylalanine 5MT= 5-methyl-DL-tryptophan A2C = L-azetidine-2-carboxylic acid PE = Plating efficiency Met = L-methionine Phe = L-phenylalanine Trp = L-tryptophan