Multiple pairs of allelic MLA immune receptor-powdery mildew AVRA effectors argue for a direct recognition mechanism

eLife

Isabel ML Saur¹  Takaki Maekawa¹  Barbara Kracher¹  Saskia Bauer¹  Xunli Lu¹  Paul Schulze-Lefert¹  Marion C Müller²  Ralph Panstruga³  Florian Kümmel³  Björn Sabelleck³  Lamprinos Franzeskakis³ 

[1] Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany;Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland;Unit of Plant Molecular Cell Biology, Institute for Biology I, RWTH Aachen University, Aachen, Germany;

关键词: plant innate immunity;    NLR receptor;    avirulence effector;    powdery mildew;    pathogen population;   

DOI  :  10.7554/eLife.44471

来源: DOAJ

【 摘 要 】

Nucleotide-binding domain and leucine-rich repeat (NLR)-containing proteins in plants and animals mediate intracellular pathogen sensing. Plant NLRs typically detect strain-specific pathogen effectors and trigger immune responses often linked to localized host cell death. The barley Mla disease resistance locus has undergone extensive functional diversification in the host population and encodes numerous allelic NLRs each detecting a matching isolate-specific avirulence effector (AVRA) of the fungal pathogen Blumeria graminis f. sp. hordei (Bgh). We report here the isolation of Bgh AVRa7, AVRa9, AVRa10, and AVRa22, which encode small secreted proteins recognized by allelic MLA7, MLA9, MLA10, and MLA22 receptors, respectively. These effectors are sequence-unrelated, except for allelic AVRa10 and AVRa22 that are co-maintained in pathogen populations in the form of a balanced polymorphism. Contrary to numerous examples of indirect recognition of bacterial effectors by plant NLRs, co-expression experiments with matching Mla-AVRa pairs indicate direct detection of the sequence-unrelated fungal effectors by MLA receptors.

【 授权许可】

Unknown