Ultrastructure of Digitalis lanata tissue cultures. Effect of gibberellic acid and SAN 9789

The anatomy of two Digitalis lanata tissue culture strains, S-1 and S-2, has been studied. The cardenolide accumulating cell aggregates consisted of highly vacuolated cells with very lobed nuclei in the periphery and a central part of meristematic cells. Sieve tube elements and companion cells and tracheids were observed in some of the cultures. The effect of gibberellic acid (GA sub(3)) and SAN 9789 on the ultrastructure of the cultures was most apparent as regards the plastids and the amounts of mitochondria. The amount of mitochondria was highly variable, but no correlation with cardenolide accumulation could be found.