Arbuscular mycorrhizal fungi (AMF), which form a symbiotic association with plant roots, are known to trigger defense responses that are similar to those triggered by biotrophic pathogens
[5]. Establishment of a successful symbiosis involves suppression of the initial defense response against AMF [6]. While the pathogenassociated molecular patterns (PAMPs) in AMF are not known, successful symbiotic association is thought to involve interactions between Myc factors of AMF and corresponding host receptors [7]. Levels of most plant hormones are known to change during establishment of AM colonization. During early establishment of symbiosis, an increase in endogenous SA levels in plants leads to an increased expression of plant defense genes, which are subsequently suppressed in order to bring about successful AM colonization [8]. JA levels on the other hand, are reported to increase, both in the roots and shoots during later stages of AM colonization [9,10]. JA is known to play a role in limiting the proliferation of symbionts like root nodulating rhizobacteria or AMF, such that its association with the plant remains mutualistic and does not become pathogenic [9]. Mutants or transgenic plants impaired in biosynthesis or signalling of JA or SA show reduced AM colonization, indicating the requirement of these hormones in establishment of a successful symbiosis