A locus conferring resistance to Colletotrichum higginsianum is shared by four geographically distinct Arabidopsis accessions.
Colletotrichum higginsianum is a hemibiotrophic fungal pathogen that causes anthracnose disease on Arabidopsis and other crucifer hosts. By exploiting natural variation in Arabidopsis we identified a resistance locus that is shared by four geographically distinct accessions (Ws-0, Kondara, Gifu-2 and Can-0). A combination of quantitative trait loci (QTL) and Mendelian mapping positioned this locus within the major recognition gene complex MRC-J on chromosome 5 containing the Toll-interleukin-1 receptor/nucleotide-binding site/leucine-rich repeat (TIR-NB-LRR) genes RPS4 and RRS1 that confer dual resistance to C. higginsianum in Ws-0 (Narusaka et al., 2009). We find that the resistance shared by these diverse Arabidopsis accessions is expressed at an early stage of fungal invasion, at the level of appressorial penetration and establishment of intracellular biotrophic hyphae, and that this determines disease progression. Resistance is not associated with host hypersensitive cell death, an oxidative burst or callose deposition in epidermal cells but requires the defense regulator EDS1, highlighting new functions of TIR-NB-LRR genes and EDS1 in limiting early establishment of fungal biotrophy. While the Arabidopsis accession Ler-0 is fully susceptible to C. higginsianum infection, Col-0 displays intermediate resistance that also maps to MRC-J. By analysis of null mutants of RPS4 and RRS1 in Col-0 we show that these genes, individually, do not contribute strongly to C. higginsianum resistance but are both required for resistance to Pseudomonas syringae bacteria expressing the Type III effector, AvrRps4. We conclude that distinct allelic forms of RPS4 and RRS1 probably cooperate to confer resistance to different pathogens.
Birker
Doris
D
Department of Plant-Microbe Interactions, Max-Planck-Institute for Plant Breeding Research, 50829 Köln, Germany.
Heidrich
Katharina
K
Takahara
Hiroyuki
H
Narusaka
Mari
M
Deslandes
Laurent
L
Narusaka
Yoshihiro
Y
Reymond
Matthieu
M
Parker
Jane E
JE
O'Connell
Richard
R
D000483:Alleles; D017360:Arabidopsis / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002874:Chromosome Mapping; D020231:Colletotrichum; D018744:DNA, Plant / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D014644:Genetic Variation; D005843:Geography; D007113:Immunity, Innate; D010935:Plant Diseases / Q000235:genetics* / Q000276:immunology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D044224:Pseudomonas syringae; D040641:Quantitative Trait Loci
D029681:Arabidopsis Proteins; D018744:DNA, Plant; D010940:Plant Proteins; C097421:rps4 protein, plant