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Avirulence Genes

  1. Thierry Rouxel,
  2. Marie-Hélène Balesdent

Published Online: 15 JAN 2010

DOI: 10.1002/9780470015902.a0021267



How to Cite

Rouxel, T. and Balesdent, M.-H. 2010. Avirulence Genes. eLS. .

Author Information

  1. INRA-Bioger, Thiverval-Grignon, France

Publication History

  1. Published Online: 15 JAN 2010
Table 1. Avirulence proteins from bacteria and their biochemical/effector functions
Avr proteinR geneHost plantPlant cell localizationBiochemical and/or effector function
Source: From Chisholm et al. 2006; Mudgett and White et al. (2005, 2000).
Pseudomonas syringae pv. glycinea
AvrARpg2SoybeanCytoplasmYopJ/AvrRxv family: interaction with plant MAP-kinases?
AvrBRpg1-bSoybeanUnknownKinase: phosphorylation of Rin4; manipulation of host jasmonic acid (JA) pathway
 Rpm1Arabidopsis thalianaUnknown
Pseudomonas syringae pv. maculicola
AvrRpm1Rpm1A. thalianaInner membrane?Kinase: phosphorylation of Rin4; inhibition of plant basal defence
Pseudomonas syringae pv. pisi
AvrPpiA1Rpm1A. thalianaUnknownUnknown
AvrRps4 (AvrPpiE)Rps4A. thalianaUnknownUnknown
Pseudomonas syringae pv. tomato
AvrPtoPto (and PRF)TomatoInner membraneKinase binding
AvrPtoBPto (and PRF)TomatoUnknownE3 ubiquitine ligase
AvrRpt2Rps2SoybeanUnknownCysteine protease: cleavage of Rin4; manipulation of host JA pathway; interferes with R-mediated defence
 Rps2A. thalianaCytoplasm
AvrRps4Rps4A. thalianaUnknownUnknown
AvrDRpg4SoybeanUnknownEnzyme involved in syringolide synthesis
Pseudomonas syringae pv. phaseolicola
HopAR1 (AvrPphB)Rps5 (and Pbs1)A. thalianaUnknownCysteine protease: cleaves Pbs1 and manipulates host JA pathway
HopX (AvrPphE)R2BeanUnknownUnknown
Xanthomonas axonopodis pv. vesicatoria
AvrBs1Bs1PepperUnknownYopJ/AvrRxv family
AvrBs2Bs2PepperCytoplasmAgrocipine synthase-like
AvrBs3Bs3PepperNucleusTranscription activator
AvrBs4Bs4TomatoUnknownAvrBs3 family
AvrBsTBsTA. thalianaUnknownYopJ/AvrRxv family; cysteine protease
AvrXv3Xv3TomatoNucleusTranscription activator
AvrXv4Xv4TomatoUnknownYopJ/AvrRxv family; cysteine protease
AvrRxvRxvBeanUnknownYopJ/AvrRxv family
Xanthomonas oryzae pv. oryzae
AvrXa3Xa3RiceUnknownAvrBs3 family
AvrXa5Xa5RiceUnknownAvrBs3 family
AvrXa7Xa7RiceNucleusAvrBs3 family; transcription activator
AvrXa10Xa10RiceProbably nucleusAvrBs3 family; transcription activator
AvrXa27Xa27RiceProbably nucleusTranscription activator
Xanthomonas campestris pv. armoraciae
Hax3Bs4TomatoUnknownAvrBs3 family
Hax4Bs4TomatoUnknownAvrBs3 family
Xanthomonas campestris pv. malvacearum
AvrB6B1CottonNucleusAvrBs3 family
Xanthomonas oryzae pv. oryzicola
Ralstonia solanacearum
PopP2Rrs1-RA. thalianaUnknownYopJ/AvrRxv family
Table 2. Fungal and oomycete avirulence genes known to-date
Avr proteinNb of AA residuesaNb of cysteinesSignal peptidePutative functionLocalization in plantsExpressionRole in virulence/fitnessR gene
  1. a

    Number of amino acid residues in the unprocessed protein.

Source: Dong et al. 2009; Kamoun 2006; Li et al. 2009; Parlange et al. 2009; Qutob et al. 2009; Stergiopoulos and de Wit 2009; van Poppel et al. 2008; Yoshida et al. 2009.
Cladosporium fulvum (host: tomato)
Avr278820Protease inhibitorApoplastIn plantaInhibits Rcr3 and other proteasesCf-2
Avr4135818Chitin-bindingApoplastIn plantaProtects against chitinasesCf-4
Avr4E121610UnknownApoplastIn plantaUnknownHcr9-4E
Avr963623Carboxypeptidase inhibitorApoplastIn plantaUnknownCf-9
Leptosphaeria maculans (host: oilseed rape)
AvrLm1205122UnknownProbably in cytoplasmOver-expressed in plantaUnknown; weakly involved in fitnessRlm1
AvrLm6144620UnknownProbably in apoplastIn plantaUnknownRlm6
AvrLm4-7143821UnknownProbably in apoplastStrongly over-expressed in plantaUnknown; involved in fitnessRlm4 and Rlm7
Fusarium oxysporum f. sp. lycopersici (host: tomato)
Avr1 (Six4)242617UnknownXylemIn plantaSuppression of I-1- and I-2-mediated resistanceI
Avr2163219UnknownXylem (translocated in cytoplasm?)In plantaUnknownI-2
Avr3 (Six1)284821UnknownXylemStimulated by living cellsAggressiveness determinantI-3
Magnaporthe oryzae (host: rice)
Avr-Pita224816MetalloproteaseCytoplasmIn plantaNone knownPi-ta
Pwl1 to Pwl3137 to 1470, 1 or 221 or 23Glycin-rich hydrophilic proteinProbably in apoplastUnknownUnknownAvirulence towards weeping lovegrass
Ace1403543nonePKS/NRPSFungal appressoriumExpressed in appressoriumUnknownPi33
AvrPia85219UnkwownCytoplasmOver-expression in plantaUnknownPia
AvrPii70319Similarity to the C2H2 zinc finger motifCytoplasmOver-expression in plantaUnknownPii
Avr-Pik/km/kp113321UnknownCytoplasmOver-expression in plantaUnknownPik, Pik-m and Pik-p
Rhynchosporium secalis (host: barley)
Nip1821022Nonspecific toxinProbably in apoplastIn vitroInduces cell necrosisRrs-1
Blumeria graminis f. sp. hordei (host: barley)
Avra102864noneUnknownProbably in cytoplasmUnknownUnknownMla10
Avrk11773noneUnknownProbably in cytoplasmUnknownUnknownMlk1
Melampsora lini (host: flax)
AvrL567150123UnknownCytoplasmExpressed in haustoriaUnknownL5, L6 and L7
AvrM314128UnknownCytoplasmExpressed in haustoriaUnknownM
AvrP1231171123Serine proteaseCytoplasmExpressed in haustoriaUnknownP, P1, P2 and P3
AvrP495728Cystine knotted peptideCytoplasmExpressed in haustoriaUnknownP4
Hyaloperonospora parasitica (host: Arabidopsis thaliana)
Atr1NdWsB311215RXLR domain for translocationCytoplasmUnknownUnknownRpp1Nd and Rpp1-WsB
Atr13187019RXLR domain for translocationCytoplasmOver-expressed in plantaUnknownRpp13
Phytophthora sojae (host: soybean)
Avr1b-1138121RXLR domain for translocationCytoplasmExpressed during early stages of plant infectionSuppresses plant deathRps1b
Avr1a122024RXLR–dEER domain for translocation; W-like domainCytoplasmIn plantaUnknownRps1a
Avr3a111–119020RXLR–dEER domain for translocation; W-like domainCytoplasmIn plantaUnknownRps3a
Avr3c220020RXLR-dEER domain for translocation; W-like domainCytoplasmExpressed during early stages of plant infectionUnknownRps3c
Phytophthora infestans (host: potato)
Avr3a147021RXLR–dEER domain for translocation; manipulation of plant ubiquitin proteasome system?CytoplasmOver-expressed in plantaSuppresses INF1-mediated plant deathR3a
Avr4287024RXLR–dEER domain for translocationCytoplasm ?UnknownUnknownR4
Table 3. List and intrinsic function of currently known viral avirulence genes
Viral avirulence geneVirus speciesVirus genusHost plantPlant resistance gene
Source: Adapted with permission from Janzac 2008.
Coat protein    
 Turnip crinckle virusCarmovirusArabidopsis thalianaHrt
 Cucumber mosaic virus (CMV)CucumovirusA. thalianaRcy1
 Potato virus X (PVX)PotexvirusPotatoNx
 Paprika & pepper mild mottle virusTobamovirusPepperL2
 Pepper mild mottle virusTobamovirusPepperL3
 Pepper mild mottle virusTobamovirusPepperL4
 Tobacco mosaic virus (TMV)TobamovirusTobaccoN
P25 protein    
 Beet necrotic yellow vein virusBenyvirusSugar beetRz-1
RNA-dependent RNA polymerase    
 CMVCucumovirusFrench beanCry
 CMVCucumovirusFrench beanRT4-4
Movement protein    
 Turnip mosaic virus (TuMV)PotyvirusOilseed rapeTurB01
 TuMVPotyvirusOilseed rapeTurB05
P3 protein    
 TuMVPotyvirusOilseed rapeTurB03
 TuMVPotyvirusOilseed rapeTurB04
 Zucchini yellow mosaic virusPotyvirusZucchiniZym
P3 & HcPro proteins    
 Soybean mosaic virusPotyvirusSoybeanRsv-1
NIa protease    
 Potato virus Y (PVY)PotyvirusPotatoRy
NSs protein    
 Tomato spotted wilt virusTospovirusPepperTsw
Viral protein genome-linked (VPg) (corresponding to a virulence factor)
 Barley yellow mosaic virusBymovirusBarleyRym-4
 Pea seed-borne mosaic virusPotyvirusPeaSbm-1
 Tobacco vein mottling virusPotyvirusTobaccova
 Bean yellow mosaic virusPotyvirusFrench beanwlv
 Rice yellow mottle virusSobemovirusRiceRymv-1
P3 protein (corresponding to a virulence factor)
 Pea seed-borne mosaic virusPotyvirusPeaSbm-2