Investigation into the Function of Pyridoxin as a Growth Factor for Excised Tomato Roots.

Open Access
Publisher Website
Google Scholar
Abstract
Thiamin, pyridoxin and niacin are required for "optimal" growth of a clone of excised roots of tomato (Lycopersicon esculentum). The clone could be maintained in a medium supplemented only with thiamin and pyridoxin. Pyridoxin was replaceable by pyridoxal or pyridoxamine. The order of activity was pyridoxal > pyridoxin > pyridoxamine. Niacin was replaceable by niacinamide. Niacinamide was, in general, the more active. Pyridoxin was replaceable in part by glycine; the replacement was greater in the presence of niacin. In medium supplemented with thiamin, pyridoxin and niacin, the addition of glycme at limiting concentrations of pyridoxin increased level of growth to that obtained with "optimal" concentration of pyridoxin. Morphogenetic effects of glycine and pyridoxin were similar although glycine appeared to exert an independent effect upon initiation of laterals. Root morphology was controlled by the balance of growth factors supplied in the medium.