ABSTRACT
Common scab of potato is a severe disease affecting tubers. This disease caused by soil-borne filamentous bacteria related to the genus Streptomyces. Generally streptomycetes were saprophytic in nature but a few species were modulated themselves to cause disease in underground parts of several plants. The causal agent of the potato common scab is the bacteria Streptomyces scabies which has worldwide occurrence. This chapter deals with factors responsible for pathogenesis, host selectivity, non-host resistance, and evolution of new pathogenic strains of S. scabies. Mostly Streptomycesspecies are not plant pathogenic in nature but sometimes their behavior similar to fungal-like strategy is very prominent for plant root attachment and infection. Transgenic expression of plant thaxtomin inhibiting proteins may control the loss due to S. scabies infection in plants. To develop transgenic approach identification of host cell targets for thaxtomin A and the nec1 protein is most important step.
