The current view of plant-pathogen interactions has revealed that the innate immune system consists of a two-branched defense response. The first branch is pathogen (microbe)-associated molecular patterns (PAMPs/MAMPs)-triggered immunity (PTI) or basal resistance, which is initiated by the direct recognition pathogen PAMPs through plant pattern-recognition receptors (PRRs) (Jones and Dangl 2006; Boller and Felix 2009).