Biochemical evidence for the activation of distinct subsets of mitogen-activated protein kinases by voltage and defense-related stimuli.
Plant Physiol
; 128(1): 271-81, 2002 Jan.
Article
em En
| MEDLINE
| ID: mdl-11788772
ABSTRACT
Activation of mitogen-activated protein (MAP) kinases is a common reaction of plant cells in defense-related signal transduction pathways. To gain insight into the mechanisms that determine specificity in response to a particular stimulus, a biochemical approach has been employed. Photoautotrophic suspension culture cells of tomato (Lycopersicon peruvianum) were used as experimental system to characterize MAP kinase activation by different stress-related stimuli. An elicitor preparation of the tomato-specific pathogen Fusarium oxysporum lycopersici was shown to result in the simultaneous induction of four kinase activities that could be separated by ion-exchange chromatography. The simultaneous activation of multiple MAP kinases was further substantiated by distinct pharmacological and immunological properties a differential sensitivity toward various protein kinase inhibitors and a differential cross-reaction with isoform-specific MAP kinase antibodies. In contrast to the two fungal elicitors chitosan and the F. oxysporum lycopersici preparation, the plant-derived stimuli polygalacturonic acid and salicylic acid were shown to activate distinctly different subsets of MAP kinases. Application of a voltage pulse was introduced as a transient stress-related stimulus that does not persist in the culture. Voltage application activates a distinct set of MAP kinases, resembling those activated by salicylic acid treatment, and generates a refractory state for the salicylic acid response. The inhibitory effect of nifedipine indicates that current application may directly affect voltage-gated calcium channels, thus, providing a tool to study various calcium-dependent pathways.
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1
Base de dados:
MEDLINE
Assunto principal:
Solanum lycopersicum
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Proteínas Quinases Ativadas por Mitógeno
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Fusarium
Idioma:
En
Ano de publicação:
2002
Tipo de documento:
Article