Andris Kleinhofs and Jayaveermuthu Nirmala
In a paper published in the Proceedings of the National Academy of Sciences, USA (PNAS), Nirmala et al. 108:14676-14681, (2011) describe the isolation and preliminary characterization of two effector proteins that coordinately induce stem rust resistance gene protein product RPG1 to become phosphorylated and initiate disease resistance signaling. The quest for these proteins started with an earlier discovery that Puccinia graminis f. sp. tritici spores initiate RPG1 phosphorylation within 5 minutes of landing on the leaf surface (Nirmala et al., Mol. Plant-Microbe Interact. 23:1635-1642, 2010). This discovery was astounding and indicated that the effectors are already present on the spore surface and that the plant has an early warning system to indicate that the enemy has landed.
Concerted action of two avirulent spore effectors activates Reaction to Puccinia graminis 1 (Rpg1)-mediated cereal stem rust resistance published in the Proceedings of the National Academy of Sciences