Abstract
1. Phyllostine has been isolated from the culture filtrate of Phyllosticta sp., a pathogenic fungus of red clover, as the principal toxic compound causing wilting and dark discoloration of leafy stem cuttings of red clover and it is closely related structurally to phyllosinol.
2. Phyllostine stimulated growth of red clover, lettuce and rice seedlings at a concentration range from 10-8 to 10-5M. These promoting effects of phyllostine on plant growth were similar to that of phyllosinol.
3. Phyllostine at concentrations between 10-6 to 2.5×10-4M promoted adventitious root formation in epicotyls of Azukia cuttings. The promoting effect of phyllostine, however, was slightly higher than phyllosinol at the same concentration level.
4. IAA-induced elongation of isolated Avena coleoptile sections was inhibited by phyllostine at a concentration range from 10-6 to 5×10-4M.
5. GA3-induced elongation of lettuce hypocotyls was slightly inhibited by phyllostine at a concentration range from 5×10-5 to 10-4M.
6. Phyllostine has antibiotic activity. The activity of phyllostine, on the whole, was about more than four times as high as that of phyllosinol.
