Die wirkung von abscisinsaure und (+)-catechin auf wachstum und efflux bei kallus von vier obstarten

Shoot explants from four tree fruit species were grown under in vitro culture conditions for studying physiological aspects of growth regulation as influenced by (+)-catechin and abscisic acid (ABA). Application of 20 resp. 40 μM abscisic acid to the standard medium reduced callus growth of three fruit species (P. avium, P. cerasus, and P. domestica). Adding (+)-catechin (68 μM) in conjunction with ABA to the media strongly counteracted the inhibitory effect of ABA alone. By contrast, callus growth of Malus domestica was promoted about 3-fold by ABA compared to control and that of the combined treatment with (+)-catechin plus ABA exceeded control by 7-fold. Membrane permeability of the calli was estimated by leakage of both electrolytes and organic compounds. Application of ABA increased exodiffusion in all four tree species as compared to controls, which was reversed by combined treatment with (+)-catechin and ABA.