Bacterial rhamnolipids and their 3-hydroxyalkanoate precursors activate <i>Arabidopsis</i> innate immunity through two independent mechanisms
Romain Schellenberger, Jérôme Crouzet, Arvin Nickzad, Lin‐Jie Shu, Alexander Kutschera, Tim Gerster, Nicolas Borie, Corinna Dawid, Maude Cloutier, Sandra Villaume, Sandrine Dhondt‐Cordelier, Jane Hubert, Sylvain Cordelier, Florence Mazeyrat‐Gourbeyre, Christian Schmid, Marc Ongena, Jean‐Hugues Renault, Arnaud Haudrechy, Thomas Hofmann, Fabienne Baillieul, Christophe Clément, Cyril Zipfel, Charles Gauthier, Éric Déziel, Stefanie Ranf, Stéphan Dorey
Abstract
Significance Activation of plant innate immunity relies on the perception of microorganisms through elicitors. Rhamnolipids and their precursor HAAs are exoproducts produced by bacteria. They are involved in bacterial surface dissemination and biofilm development. As these compounds are released in the extracellular milieu, they have the potential to be perceived by the plant immune system. Our work shows that both compounds independently activate plant immunity. We demonstrate that HAAs are perceived by the receptor protein kinase LORE. By contrast, rhamnolipids are not sensed by LORE but activate a noncanonical immune response influenced by the sphingolipid composition of the plant plasma membrane. Thus, plants can sense bacterial molecules as well as their direct precursors to trigger distinct immune responses.