Phytotoxin Produced by Pseudomonas glumue Kurita et Tabei, a Causal Bacterium of the Grain and Seedling Rot of Rice

Abstract

The phytotoxin produced by Pseudomonas glumae, the causal agent of bacterial grain and seedling rot of rice, was purified and characterized. The ultraviolet and visible absorption spectrum of the phytotoxin exhibited two maxima at 260nm and 399nm in 80% aqueous methanol. In the infrared absorption spectrum, main bands at 2,800 3,00Ocm-‘, 1,68Ocm-‘, 1,540cm.’ and 1,05Ocm-’ were observed, suggesting the presence of a methyl group, a ketone group, a benzene ring and a carbon- hydrogen bond, respectively. The molecular weight of this substance was determined as 193 and the molecular formula was decided as C7H7Ns02 by a high resolution EI mass spectrometry. The phytotoxin was isolated noi only from the PS broth, but also from rice seedling infected with the causal bacterium. This phytotoxin might be related to the pathogenicity of P. glumae.