Molecular Determinants of Resistance Activation and Suppression by Phytophthora infestans Effector IPI-O

• DOI: 10.1371/journal.ppat.1002595
• Publication Date: 2012-03-15T21:51:23Z
• Authors: Yu Chen; Zhenyu Liu; Dennis A. Halterman
• Keywords: Phytophthora infestans; Hypersensitive response; Oomycete; R gene

Despite intensive breeding efforts, potato late blight, caused by the oomycete pathogen Phytophthora infestans, remains a threat to production worldwide because newly evolved strains have consistently overcome major resistance genes. The RB gene, derived from wild species Solanum bulbocastanum, confers most P. infestans through recognition of members effector family IPI-O. While majority IPI-O proteins are recognized elicit (e.g. IPI-O1, IPI-O2), some able elude detection IPI-O4). In addition, IPI-O4 blocks leading inactivation RB-mediated programmed cell death. Here, we report results that elucidate molecular mechanisms governing elicitation or suppression Our data indicate self-association coiled coil (CC) domain as well physical interaction between this and effectors IPI-O1. We identified four amino acids within critical for with CC one these acids, at position 129, determines hypersensitive response (HR) in planta. IPI-O1 mutant L129P fails induce HR presence while P129L gains ability an HR. Like IPI-O4, is also suppress mediated RB, indicating step evolution gene family. point model which can affect function domain.