XPNPEP2 and bacterial infectious disease: In general, plants that have lost a MAMP; FLS2, EFR, CERK1‐2 or DAMP receptor, PepR1‐1 × 2‐1, can sustain normal Fv/Fm during bacterial infection by priming with an alternative M/DAMP that is, efr, cerk1‐2 and pepR1‐1 × 2‐1 plants retain normal Fv/Fm with flg22 pretreatment (Figures 1, 2, 5e,f and 9).