Existence of a Tryptophan-Niacin Relationship in Corn

Abstract

Two expts. indicate the existence of a tryptophan-niacin relationship in corn which is independent of vit. Bg. The seeds were sterilized with HgCl2 and soaked in water overnight. The embryos were removed by sterile excision and placed in individual flasks containing nutrient material. Expt. I consisted of adding various combination concns. of L-tryptophan and vit. B6 to the basal nutrient soln. The embryos were grown in the dark at 25[degree]G for 10 days and assayed for niacin by the microbiological method. Results revealed niacin synthesis in excess of that of the controls to be a direct function of the L-tryptophan supply and independent of the concn. of the vit. Bg. In expt. II, L-tryptophan and vit. B6 were added singly and in combination to the medium. The addition of 1000 [mu]g. L-tryptophan singly and in combination with vit. Bg resulted in a statistically significant increase in niacin synthesis over that of the controls. L-tryptophan and vit. Bg in combination did not cause a significant increase in niacin synthesis over L-tryptophan alone. Nor did vit. B6 alone cause significant increases of niacin synthesis over that of the controls.