The Biosynthesis of Folic Acid Compounds in Plants

III. Distribution of the Dihydropteroate-synthesizing Enzyme in Plants

Abstract

Dihydropteroate synthetase was widely distributed in the higher plants tested, and a high enzyme activity was found in green leaves. In the early germination stage in pea seedlings, most of the enzyme activity existed in the cotyledon. With growth, a remarkable increase in enzyme activity in the root plus shoot was observed. The amount of Streptococcus faecalis R-active substances in root plus shoot rapidly increased during the germination of pea seedlings.
A large percentage of the enzyme activity was located in the mitochondrial fractions of both pea and soybean seedlings. Most of the S. faecalis R-active substances in pea seedlings existed in the soluble fraction from the cytoplasm.