Mamoun M, Moquet F, Laffitte J, Olivier J M
INRA, Station de Recherches sur les Champignons, Villenave d'Ornon, France.
FEMS Microbiol Lett. 1997 Aug 1;153(1):215-9. doi: 10.1111/j.1574-6968.1997.tb10484.x.
Pseudomonas tolaasii is responsible for brown blotch symptoms on Agaricus bisporus. Investigations among 15 P. tolaasii wild-type strains revealed the existence of an extra-genomic factor. Pseudomonas tolaasii CNBP2152D, a spontaneous derivative of the wild-type strain CNBP2152 which has lost the factor, exhibited a significant decline in pathogenicity. Comparison of blotch symptoms induced by toxins extracted from CNBP2152 and CNBP2152D showed that the extragenomic factor mediates toxin production and efficiency.