3-Hydroxyuridine, an allelopathic factor of an African tree, Baillonella toxisperma

Abstract

A plant growth inhibitor was isolated from Baillonella toxisperma, a plant which may cause an allelopathic effect in the tropical rain forest of Cameroon. From spectral and chemical evidence, the inhibitor was identified as 3-hydroxyuridine. It inhibited both hypocotyl and root growth of cucumber and radish seedlings, and also inhibited root growth of rice seedlings, but not sheath growth. The foliar treatment of 3-hydroxyuridine exhibited inhibitory effects on the growth of a wide variety of weeds; however, it was quite ineffective against the growth of the crop plant, Zea mays. The strong plant growth inhibitory activity, together with the occurrence in most parts of the tree at high levels, indicated that 3-hydroxyuridine may be involved in the allelopathy of the tree.