Archivio Journal of Plant Pathology

Abstract:

Systemic acquired resistance (SAR) to virus infections should be carefully distinguished from such resistance regarding other plant pathogens. In particular: (i) SAR operates against localized virus infection by limiting cell-to-cell spread of virus, through a mechanism involving an accelerated hypersensitive reaction without preventing virus replication; (ii) SAR does not operate against systemic virus infection; it neither limits virus replication nor alleviates symptoms. SAR may therefore play an important part in limiting many infectious plant diseases, but must be viewed with less enthusiasm in regard to viruses.