Plants have evolved sophisticated surveillance systems that recognize conserved microbial pattems or secreted pathogen effector proteins.Intracellular immune receptors, possessing nucleotide binding and C-terminal leucine rich repeat domains (NLRs), can recognize pathogen effectors delivered inside host cells during infection.Pattern recognition receptors (PRRs) are also critical immune receptors, recognizing conserved microbial patterns, such as bacterial flagellin.