Abstract
Plant recognition of elicitors derived from pathogens induce various resistant reactions, including production of reactive oxygen species, hypersensitive cell death and accumulation of phytoalexin. Previously, we isolated a ceramide elicitor form Phytophthora infestans, which activate O2- production of potato suspension-cultured cells. In this study, we employed 9 ceramide-related compounds to test their elicitor activity. Although, none of these compounds induced O2- production, N,N-dimethylspingosine (DMS) induced accumulation of phytoalexin in potato tubers. In potato, tobacco and Nicotiana benthamiana, DMS also induced cell death. DMS-treated potato cells stained by DAPI showed chromatin condensation, and isolated DNA showed ladder pattern, confirmed DMS-induced cell death is programmed cell death.
In N. benthamiana we applied virus-induced gene silencing to investigate the involvement of phytohormone signaling on DMS-induced cell death. Silencing of Ein2, Coi1, Sid2 and Npr1 had no effect on DMS-induced cell death, inducing phytohormone signaling play no role in cell death induced by DMS.
