The necrotroph Botrytis cinerea induces a non-host type II resistance mechanism in Pinus pinaster suspension-cultured cells.
Models of non-host resistance have failed to account for the pathogenicity of necrotrophic agents. During the interaction of Pinus pinaster (maritime pine) with the non-host necrotrophic pathogen Botrytis cinerea, the generation and scavenging of reactive oxygen species (ROS) and the induction of the hypersensitive response (HR) were analyzed. Elicitation of maritime pine suspended cells with B. cinerea spores resulted in the biphasic induction of ROS. The phase I oxidative burst was dependent on calcium influx, while the phase II oxidative burst also depended on NADPH oxidase, protein kinase activity, and de novo transcription and protein synthesis. A decline was observed in catalase (CAT) and superoxide dismutase (SOD) activity, together with the down-regulation of Fe-Sod1, chlCu, Zn-Sod1 and csApx1, suggesting a coordinated response towards a decrease in the ROS-scavenging capacity of maritime pine cells during challenge. Following the second oxidative burst, programmed cell death events characteristic of the HR were observed. The results suggest the ROS-mediated and cell-breach-independent activation of Type II non-host resistance during the P. pinaster-B. cinerea interaction.
Azevedo
Herlânder
H
Grupo de Bioquímica e Fisiologia Molecular de Plantas, Departamento de Biologia, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal. hazevedo@bio.uminho.pt
Lino-Neto
Teresa
T
Tavares
Rui Manuel
RM
D000975:Antioxidants; D017209:Apoptosis / Q000502:physiology; D020171:Botrytis / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D006706:Homeostasis / Q000502:physiology; D028223:Pinus / Q000166:cytology* / Q000378:metabolism* / Q000382:microbiology; D017382:Reactive Oxygen Species / Q000378:metabolism
D000975:Antioxidants; D017382:Reactive Oxygen Species; D002118:Calcium