Effect of Light on a Growth Inhibitor in Wheat Roots.

Four day-old excised roots and intact roots of wheat plant grown in the dark and in the light were extracted. The extracts were separated by paper chromatography and tested by cress seed germination and wheat root growth tests. The following results were obtained: A significant inhibiting action appeared only in the acid fraction. An inhibiting zone was detected in this fraction, judging from Rf value supposed to be inhibitor-β. The content of inhibitor-β was much higher in the root tips grown in the light than in those grown in the dark. Hence it is concluded that one of the mechanisms of light inhibition may be a light-induced increase in the content of inhibitor-β in the root tips. [ABSTRACT FROM AUTHOR]