PRL and infection: For example, nat-siRNAATGB2, which originate from the overlapping region of transcripts of a small GTP-binding protein ATGB2 and a pentatricopeptide repeat-like (PPRL) gene, is induced upon infection by P. syringae carrying effector avrRpt2, and silences PPRL that negatively regulates RPS2-mediated disease resistance (Katiyar-Agarwal et al. 2006).