Fig. 6

Potato immunity responses against P. infestans (A) and potyvirus (B). A Ligands secreted by P. infestans bind to pattern recognition receptors (PRRs), triggering immune complex formation and downstream kinase phosphorylation. StMAPKs cascades are phosphorylated to activate related transcriptional factors and induce ROS burst. To combat PTI immunity, P. infestans secrete various AVRs to aim specific protein targets. For endomembrane trafficking: AVR1 to Sec5, PexRD54 to ATG8CL, AVR3a to DRP2. For protein degradation: AVR3a to CMPG1, AVR8 to StDeSI2, and Pi02860 to NRL1, SWAP70. For StMAPK kinase activity, both PexRD2 and Pi22926 are involved. AVR2 interacts with StBSL1 to induce StCHL1. PiSF13 targets StUBK to reduce immunity responses. B Once potyvirus enters the plant cell through insect media, the coat protein (CP) is recognized and bound by a TIR-NLR immune receptor (e.g. Ry_sto), and downstream responses are induced. The VPg binds to the initiation factor eIF4E to initiate viral transcription. eIF4E variants can escape interaction and improve resistance. Viruses spread through plasmodesmata with the help of TGBp1. Under virus invasion, StREM promotes callose deposition and inhibit TGBp1 function