Inhibition of Metabolism in Avena Coleoptile Tissue by Fluoride

Abstract

Following treatment of decapitated sections with 0.01 N_NaF for 6 hours at pH 6, an 80% inhibition of growth in the presence of 0.05 [image] glucose and 2.9 x 10-5 [image] indoleacetic acid ensued, followed by partial recovery in fluoride-free solutions. Studies of glucose utilization in the absence of indoleacetic acid showed that absorption of uniformly labeled C14 glucose was barely affected but inhibition of incorporation of C14 into cellulose and the glucose components of the aqueous and dilute acid soluble wall fractions was particularly notable. Production of C14O2 from glucose-6-C14 was inhibited by fluoride much more than was production of C14O2 from glucose-1-C14. Production of C14O2 from glucose-2-C14 was not affected. A high C6/C2 ratio for C14 O2 suggested several alternative explanations for the fluoride effect on catabolism. At lower levels of inhibition of growth, the effect on catabolism disappeared but certain effects on the cell wall were still apparent. Interference with the metabolism of specific components of the wall including cellulose is considered to be a factor in fluoride inhibition of growth.