Plant growth regulators from ash strains of Pseudomonas syringae subsp. savastanoi.
IAA and its methyl ester were isolated from cultures of Pseudomonas syringae subsp. savastanoi that had been isolated from ash [Fraxinus]. However, typical strains produced only small amounts of the auxins, whereas relatively high amounts of the above phytohormones accumulated in the culture medium of an atypical strain. No cytokinins were isolated from cultures of the typical ash strains. Conversely, four cytokinins (dihydrozeatin and its 9-β-riboside, and trans-zeatin riboside and its 1′-methyl derivative) were found in an atypical strain culture.