Local and systemic stress responses in Norway spruce: Similarities in gene expression between a compatible pathogen interaction and drought stress

Local- and systemic-induced defense responses were investigated in the Norway spruce– Rhizoctonia sp. pathosystem and compared with drought alone or a combination of the two stresses using real-time reverse transcription (RT)-PCR. The compatible pathogen stress resulted in a transient systemic induction of selected defense-related gene transcripts in the shoot and a persistent local induction in the roots. Drought led to a similar but delayed host response, while the combined stress gave larger and earlier changes in transcripts than for the two stresses separately. Thus, distinguishing between the effect of a root infection and drought based on systemic transcription patterns may be feasible especially when the temporal expression patterns are closely monitored.