Plant Pathology Department


Date of this Version



Published in American Journal of Botany, Vol. 41, No. 5 (May, 1954), pp. 390-394. Copyright 1954 by Botanical Society of America. Used by permission.


The secretion of extracellular enzymes by intact cells of higher plants apparently is a rare occurrence. One example of it is the secretion of an extra, cellular amylase by the tissue of a virus-induced tumor from the root of Rumex wetosa L. An amylase is secreted in sufficient quantities by this tissue to enable it to grow as well in vitro on a starch-containing medium as on one containing sucrose.