SA is well known naturally occurring signaling molecule that
play’s a key role in establishing and signaling a defense response
against various pathogenic infections (Malamy et al., 1990; Durner
et al., 1997) and also induces systemic acquired resistance (SAR)
in plants. The induction of SAR, after a localized infection, requires
some kind of long distance communication mediator. A survey of
literature indicates that salicylic acid moves from infected organs
of plants to the non-infected ones through phloem