SlEpk1 contributes to programmed cell death associated with bacterial effector-plant R protein interaction. N. benthamiana silenced plants were syringe-infiltrated with A. tumefaciens carrying different effector/R gene pairs to elicit PCD. PCD percentage was calculated as described in the Materials and methods using 12 plants per construct. Asterisks indicate significant differences compared with Ec1-silenced plants using Fisher’s exact test (P <0.01). Ec1, Escherichia coli fragment 1; Pto, resistance to Pseudomonas syringae pv. tomato; Bax, Bcl-2-associated X protein; AvrPtoB1-387, AvrPtoB lacking the E3-ligase domain; Rx2, resistance to potato virus X (PVX); CP, coat protein of PVX; RPP13, recognition of Hyaloperonospora parasitica 13; ATR13Δ41, Arabidopsis thaliana-recognized 13 with 41 amino acids of the signal peptide deleted; Gpa2, Globodera pallida 2; RBP-1, Ran-binding protein 1.