A Defense Pathway Linking Plasma Membrane and Chloroplasts and Co-opted by Pathogens

Medina-Puche, Laura; Tan, Huang; Dogra, Vivek; Wu, Mengshi; Rosas-Diaz, Tabata; Wang, Liping; Ding, Xue; Zhang, Dan; Fu, Xing; Kim, Chanhong; Lozano-Duran, Rosa

Publicación: CELL
VL / 182 - BP / 1109 - EP / +
Chloroplasts are crucial players in the activation of defensive hormonal responses during plant-pathogen interactions. Here, we show that a plant virus-encoded protein re-localizes from the plasma membrane to chloroplasts upon activation of plant defense, interfering with the chloroplast-dependent anti-viral salicylic acid (SA) biosynthesis. Strikingly, we have found that plant pathogens from different kingdoms seem to have convergently evolved to target chloroplasts and impair SA-dependent defenses following an association with membranes, which relies on the co-existence of two subcellular targeting signals, an N-myristoylation site and a chloroplast transit peptide. This pattern is also present in plant proteins, at least one of which conversely activates SA defenses from the chloroplast. Taken together, our results suggest that a pathway linking plasma membrane to chloroplasts and activating defense exists in plants and that such pathway has been co-opted by plant pathogens during host-pathogen co-evolution to promote virulence through suppression of SA responses.

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