Understanding oomycete effector functions to establish plant infections
Final Report Abstract
The results having obtained so far for this project give us profound insights into the mechanism of the recognition of a particular eukaryotic effector protein by a plant resistance protein. It was never described before that R proteins relocalise to vesicles after effector recogniton. RPM1, a CC-NBS-LRR resistance protein from Arabidopsis, was shown to be not only activated on, but can also able to mediate HR from the plasma membrane. This finding strengthens the idea of plant NB-LRR proteins able to trigger HR signaling from various locations in the cell. In other words, the relocalisation of R3a to vesicles which is associated with a close proximity to Avr3aKI indicates that on these vesicles activated R3a mediates the HR signaling (in my experiments the HR of course is prevented due to the N-terminal YFP). How important endocytosis for plant defence is, has been shown previously for the FLS2 receptor. Experiments being done at the moment concentrate on correlating relocalisation of R3a with its function: use of constitutively active R3a for localisation experiments, prevention of R3ahypersensitivity using different vesicle transport inhibitors and co-immunoprecipitation experiments in planta to find not only the guardee of R3a, but also the virulence target of Avr3a. Eventually we hope to publish a model that describes for the first time the activation of effectortriggered immunity by a plant resistance protein that relocalises to vesicles after recognition of eukaryotic effector proteins.
Publications
- 2010. Phytophthora infestans effector Avr3a is essential for virulence and manipulates plant immunity by stabilizing host E3 ligase CMPG1. PNAS 107: 99099-9914
Bos, J.I.B., Armstrong, M.R., Gilroy, E.M., Boevink, P.C., Hein, I., Taylor, R.M., Zhendong, T., Engelhardt, S., Vetukuri, R.R., Harrower, B., Dixelius, C., Bryan, G., Sadanandom, A., Whisson, S.C., Kamoun, S. and Birch, P.R.J.
