Browsing by discipline "Biotechnology (METSÄ) (Plant-microbe interactions)"

Plant pathology is an important area of research for maintaining food security and ecosystem services. Many model systems have been developed to study plant diseases in a more practical environment such as in Arabidopsis thaliana. However, among the ten most important pathogens for research or economy, dimorphic plantassociated yeasts and pathogens of trees are missing. Plants are constantly challenged with a huge number of potential pathogens but the development of disease remains the exception. This complete resistance against a pathogen is termed non-host resistance. Some yeasts are capable to induce resistance in plants against other pathogens. This has potential for biological control measures. Our aim was to develop a model system for studying non-host and induced resistance with the dimorphic birch pathogen Taphrina betulina in Arabidopsis. We studied the mechanistic details conferring non-host resistance to T. betulina by challenging stress signalling mutants with the pathogen and observing symptom development, root growth, fungal establishment in planta and phototoxic stress. The results suggest that type I non-host resistance protects Arabidopsis against Taphrina. This is dependent on the EIN2 protein and mediated through an antagonism between the salicylic acid and jasmonic acid defence signalling pathways. Pre-inoculation with Taphrina betulina surprisingly increased growth of Pseudomonas syringae. We suggest that this is due to the activation of jasmonic acid and ethylene signalling which antagonise the salicylic acid defences required for Pseudomonas resistance. In this study, we showed that Arabidopsis is a non-host for Taphrina betulina and that this pathosystem can be used as a model for studying the mechanisms of nonhost resistance. These insights can give information about possible properties leading to susceptibility in the host. There is a large scope of opportunities for further study into this model.