Besides, direct antagonistic activi

Besides, direct antagonistic activity by the production of various bacterial metabolites and induction of systemic resistance by PGPR against diseases have been established as a new mechanism by which plants defend themselves against pathogen attack. Soil inoculum of Pseudomonas fluorescens induces disease resistance against foliar pathogens in several crops
(Peer et al, 1991; Wei et al, 1991). Any plant has endogenous defense mechanisms that can be induced by insects and pathogens. It is well known that the defense genes are inducible genes and appropriate stimuli or signals are needed for activation. Activation of the plant’s own defense mechanisms by prior application of a biological inducer is thought to be a novel plant protection strategy.