Studies of the Growth in Culture of Excised Wheat Roots VII. Enhancement of Growth by an Unidentified Volatile Product of Root Metabolism.

Evidence is presented that the growth of cultured wheat roots is entranced in closed culture systems not only by carbon dioxide but by a further and apparently very volatile product of root metabolism. The formation of this second growth-stimulating substance is not considered to depend upon a reduction of oxygen tension in the culture system. Unlike ethanol the activity of the volatile promoter does not depend upon illumination of the cultures. The volatile promoter cannot be effectively absorbed by a number of gas absorbents. Attempts to demonstrate ethylene production by the roots have been unsuccessful. [ABSTRACT FROM AUTHOR]