Induced Systemic Resistance: Certain bacterial interactions with root enables the associated plant to develop resistance against potent pathogens. This phenomenon is termed as Induced Systemic Resistance (ISR) and has been noted to be exhibited by both associative and endophytic bacteria (Table 2) (van Loon, 2007). It was first noticed in carnation and cucumber where inoculation with selected PGPB (rhizobacteria) reduced susceptibility to wilt and foliar disease respectively. In contrast to many biocontrol mechanisms, extensive colonization of the root system is not required for ISR to be exerted