Pseudomonas savastanoi pv. fraxini

Pseudomonas savastanoi is a gram-negative plant pathogenic bacterium that infects a variety of plants. It was once considered a pathovar of Pseudomonas syringae, but following DNA-relatedness studies, it was instated as a new species. It is named after Savastano, a worker who proved between 1887 and 1898 that olive knot are caused by bacteria. The pathovar of greatest economical significance is Pseudomonas savastanoi pv. savastanoi, which causes the disease olive knot. Symptoms include formation of galls on infected trees; tumour formation is induced by indoleacetic acid biosynthesis by the bacteria, in a similar manner to the well-studied crown gall pathogen, Agrobacterium tumefaciens.

from Wikipedia