Research Notes: Identification of a dsp DNA Region Controlling Aggressiveness of Pseudomonas solanacearum. Matthieu Arlat. Laboratoire de Biologie Moléculaire des Relations Plantes-Microorganismes, CNRS-INRA, 31326 Castanet-Tolosan Cedex, France. Christian Boucher. Laboratoire de Biologie Moléculaire des Relations Plantes-Microorganismes, CNRS-INRA, 31326 Castanet-Tolosan Cedex, France.. MPMI 4:211-213. Accepted 14 December 1990. Copyright 1991 The American Phytopathological Society.

Tn5-induced mutations carried by three nonpathogenic mutants of Pseudomonas solanacearum were found to be located in different regions of the genome. Localized mutagenesis of one of these DNA regions showed that it covers approximately 15 kilobases and contains genes simultaneously modulating aggressiveness toward tomato and sensitivity to acidic pH.