Research Notes: Cloning of the Genes for Indoleacetic Acid Synthesis from Pseudomonas syringae pv. syringae. Frank F. White. Department of Plant Pathology, Kansas State University, Manhattan 66506-5502. Steven F. Ziegler(2). (2)Immunex Corporation, Seattle, WA 98101 U.S.A. MPMI 4:207-210. Accepted 13 December 1990. Copyright 1991 The American Phytopathological Society.

Genes for indole-3-acetic acid (IAA) biosynthesis in Pseudomonas syringae pv. syringae, the causal agent of brown spot disease in bean, were identified and cloned by using a DNA fragment that contained the iaaM and iaaH genes from P. s. pv. savastanoi as a probe. A 2.8-kb EcoRI fragment was detected in DNA from six strains of P. s. pv. syringae that were originally isolated from bean and pear. Strains of P. s. pv. syringae from tomato, wheat, and corn, and two strains of P. s. pv. pisi were negative. The results suggest that the subgroup of P. s. pv. syringae strains from bean plants and possibly strains from pears synthesize IAA via the iaaM/iaaH pathway.