Pironetin, a novel plant growth regulator produced by Streptomyces sp. NK10958. I. Taxonomy, production, isolation and preliminary characterization.

A novel plant growth regulator, pironetin, was isolated from the culture broth of Streptomyces sp. NK10958. It was extracted from the culture broth with ethyl acetate and purified by column chromatographies. Pironetin showed 23% inhibition on the growth of rice plants without any loss of crop yield at 10 g/a on 9 days before heading.