Mechanisms of systemic resistance to pathogen infection in plants and their potential application in forestry

BACKGROUND: The complex systemic responses of tree species to fight pathogen infection necessitate attention due to the potential for yield protection in forestry. RESULTS: In this paper, both the localized and systemic responses of model plants, such as Arabidopsis and tobacco, are reviewed. These responses were compared to information available that investigates similar responses in woody plant species and their key differences were highlighted. In addition, tree-specific responses that have been documented were summarised, with the critical responses still relying on certain systemic acquired resistance pathways. Importantly, coniferous species have been shown to utilise phenolic compounds in their immune responses. Here we also highlight the lack of focus on systemic induced susceptibility in trees, which can be important to forest health. CONCLUSIONS: This review highlights the possible mechanisms of systemic response to infection in woody plant species, their potential applications, and where research may be best focused in future.