详细
The work analyzed nine strains of Pectobacterium atrosepticum (Pca) and obtained new information about the properties of the pathogen and the regulation of its main virulence factors. Anionic groups (PO34–) were identified in exopolysaccharides (EPS) of Pca, which differ in quantity among different strains and may contribute to the formation of denser biofilms. Most Pca strains inhibited the growth of potato plants in vitro to varying degrees, but one of them (strain 426) significantly activated this indicator in plants of the resistant potato variety Lugovskoy. Based on the totality of symptoms of the disease (chlorosis, necrosis, wilt, inhibition of growth rate), all strains of P. atrosepticum were divided according to the degree of virulence. In addition, it was shown that incubation of bacteria with a homogenate from potato plants in vitro modulated the activity of pectinase Pca: a homogenate from plants of the resistant potato variety Lugovskoy inhibited the activity of exopectinase, and from the susceptible variety Lugovskoy activated it. At the same time, the exopectinase activity of the avirulent strain 426 was inhibited to the greatest extent. It is assumed that this was the reason for stimulating the growth of potato plants in vitro of a resistant variety.