RT Journal Article
SR Electronic
T1 Relocalization of Late Blight Resistance Protein R3a to Endosomal Compartments Is Associated with Effector Recognition and Required for the Immune Response
JF The Plant Cell
JO Plant Cell
FD American Society of Plant Biologists
SP 5142
OP 5158
DO 10.1105/tpc.112.104992
VO 24
IS 12
A1 Engelhardt, Stefan
A1 Boevink, Petra C.
A1 Armstrong, Miles R.
A1 Ramos, Maria Brisa
A1 Hein, Ingo
A1 Birch, Paul R.J.
YR 2012
UL http://www.plantcell.org/content/24/12/5142.abstract
AB An important objective of plant–pathogen interactions research is to determine where resistance proteins detect pathogen effectors to mount an immune response. Many nucleotide binding–Leucine-rich repeat (NB-LRR) resistance proteins accumulate in the plant nucleus following effector recognition, where they initiate the hypersensitive response (HR). Here, we show that potato (Solanum tuberosum) resistance protein R3a relocates from the cytoplasm to endosomal compartments only when coexpressed with recognized Phytophthora infestans effector form AVR3aKI and not unrecognized form AVR3aEM. Moreover, AVR3aKI, but not AVR3aEM, is also relocalized to endosomes in the presence of R3a. Both R3a and AVR3aKI colocalized in close physical proximity at endosomes in planta. Treatment with brefeldin A (BFA) or wortmannin, inhibitors of the endocytic cycle, attenuated both the relocalization of R3a to endosomes and the R3a-mediated HR. No such effect of these inhibitors was observed on HRs triggered by the gene-for-gene pairs Rx1/PVX-CP and Sto1/IpiO1. An R3a(D501V) autoactive MHD mutant, which triggered HR in the absence of AVR3aKI, failed to localize to endosomes. Moreover, BFA and wortmannin did not alter cell death triggered by this mutant. We conclude that effector recognition and consequent HR signaling by NB-LRR resistance protein R3a require its relocalization to vesicles in the endocytic pathway.GlossaryNB-LRRnucleotide binding–Leu-rich repeatCCcoiled coilHRhypersensitive responseYFPyellow fluorescent proteinhpthours post-treatmentGFPgreen fluorescent proteinPVCprevacuolar compartmentCFPcyan fluorescent proteinBiFCbimolecular fluorescence complementationBFAbrefeldin APVXPotato virus XERendoplasmic reticulumMHDMet-His-AspY2Hyeast two-hybridPIPphosphoinositideCSMcomplete supplement medium