Pathogenic mechanisms in the species of Streptomyces causing potato common scab

The causative agent of scab disease or potato scab, which are different species of the genus Streptomyces, has a relatively wide host range. This disease has caused a lot of economic damage in most of the cultivating areas. Researches on the virulence mechanisms of plant-pathogenic Streptomyces spp. have shown the importance of the thaxtomin phytotoxins as main pathogenicity determinants produced by several species. In addition, other phytotoxic specialized metabolites such as coronafacoil, Concanamycin and FD-891 along with the production of phytohormones and secretory proteins may have a role in the development or severity of the disease caused by species related to this genus. There are wide range of pathogenic factors in the species related to the Streptomyces genus. This phenomenon shows the potential of the species of each region to accept pathogenic genes and create new species, which is very important and decisive from the disease management point of view. The purpose of this review is to gain an understanding of the molecular mechanisms of plant pathogenicity to use improved management methods to control potato scab disease and other plant diseases caused by species related to this genus.