CML9, an Arabidopsis calmodulin-like protein, contributes to plant innate immunity through a flagellin-dependent signalling pathway

Louis-Jérôme Leba, Cécilia Cheval, Inmaculada Ortiz-Martín, Benoit Ranty, Carmen R. Beuzón, Jean-Philippe Galaud and Didier Aldon

Résumé:

Many stimuli such as hormones and elicitors induce changes in intracellular calcium levels to integrate information and activate appropriate responses. The Ca²⁺ signals are perceived by various Ca²⁺ sensors, and calmodulin (CaM) is one of the best characterized in eukaryotes. Calmodulin-like (CML) proteins extend the Ca²⁺ toolkit in plants; they share sequence similarity with the ubiquitous and highly conserved CaM but their roles at physiological and molecular levels are largely unknown. Knowledge of the contribution of Ca²⁺ decoding proteins to plant immunity is emerging, and we report here data on Arabidopsis thaliana CML9, whose expression is rapidly induced by phytopathogenic bacteria, flagellin and salicylic acid. Using a reverse genetic approach, we present evidence that CML9 is involved in plant defence by modulating responses to bacterial strains of Pseudomonas syringae. Compared to wild-type plants, the later responses normally observed upon flagellin application are altered in knockout mutants and over-expressing transgenic lines. Collectively, using PAMP treatment and P. syringae strains, we have established that CML9 participates in plant innate immunity.

Revue:

The Plant Journal

Lien:

https://onlinelibrary.wiley.com/doi/10.1111/j.1365-313X.2012.05045.x/full