Apoplastic Effectors Secreted by Two Unrelated Eukaryotic Plant Pathogens Target the Tomato Defense Protease Rcr3

Overview

Journal Proc Natl Acad Sci U S A

Specialty Science

Date 2009 Jan 28

PMID 19171904

Citations 107

Authors

Jing Song

Joe Win

Miaoying Tian

Sebastian Schornack

Farnusch Kaschani

Muhammad Ilyas

Renier A L van der Hoorn

Sophien Kamoun

Affiliations

Soon will be listed here.

Abstract

Current models of plant-pathogen interactions stipulate that pathogens secrete effector proteins that disable plant defense components known as virulence targets. Occasionally, the perturbations caused by these effectors trigger innate immunity via plant disease resistance proteins as described by the "guard hypothesis." This model is nicely illustrated by the interaction between the fungal plant pathogen Cladosporium fulvum and tomato. C. fulvum secretes a protease inhibitor Avr2 that targets the tomato cysteine protease Rcr3(pim). In plants that carry the resistance protein Cf2, Rcr3(pim) is required for resistance to C. fulvum strains expressing Avr2, thus fulfilling one of the predictions of the guard hypothesis. Another prediction of the guard hypothesis has not yet been tested. Considering that virulence targets are important components of defense, different effectors from unrelated pathogens are expected to evolve to disable the same host target. In this study we confirm this prediction using a different pathogen of tomato, the oomycete Phytophthora infestans that is distantly related to fungi such as C. fulvum. This pathogen secretes an array of protease inhibitors including EPIC1 and EPIC2B that inhibit tomato cysteine proteases. Here we show that, similar to Avr2, EPIC1 and EPIC2B bind and inhibit Rcr3(pim). However, unlike Avr2, EPIC1 and EPIC2B do not trigger hypersensitive cell death or defenses on Cf-2/Rcr3(pim) tomato. We also found that the rcr3-3 mutant of tomato that carries a premature stop codon in the Rcr3 gene exhibits enhanced susceptibility to P. infestans, suggesting a role for Rcr3(pim) in defense. In conclusion, our findings fulfill a key prediction of the guard hypothesis and suggest that the effectors Avr2, EPIC1, and EPIC2B secreted by two unrelated pathogens of tomato target the same defense protease Rcr3(pim). In contrast to C. fulvum, P. infestans appears to have evolved stealthy effectors that carry inhibitory activity without triggering plant innate immunity.

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References

Lindbo J . TRBO: a high-efficiency tobacco mosaic virus RNA-based overexpression vector. Plant Physiol. 2007; 145(4):1232-40. PMC: 2151719. DOI: 10.1104/pp.107.106377. View

van der Biezen E, Jones J . Plant disease-resistance proteins and the gene-for-gene concept. Trends Biochem Sci. 1998; 23(12):454-6. DOI: 10.1016/s0968-0004(98)01311-5. View

Huitema E, Bos J, Tian M, Win J, Waugh M, Kamoun S . Linking sequence to phenotype in Phytophthora-plant interactions. Trends Microbiol. 2004; 12(4):193-200. DOI: 10.1016/j.tim.2004.02.008. View

van Esse H, Vant Klooster J, Bolton M, Yadeta K, van Baarlen P, Boeren S . The Cladosporium fulvum virulence protein Avr2 inhibits host proteases required for basal defense. Plant Cell. 2008; 20(7):1948-63. PMC: 2518240. DOI: 10.1105/tpc.108.059394. View

Abramovitch R, Martin G . AvrPtoB: a bacterial type III effector that both elicits and suppresses programmed cell death associated with plant immunity. FEMS Microbiol Lett. 2005; 245(1):1-8. DOI: 10.1016/j.femsle.2005.02.025. View

Kruger J, Thomas C, Golstein C, Dixon M, Smoker M, Tang S . A tomato cysteine protease required for Cf-2-dependent disease resistance and suppression of autonecrosis. Science. 2002; 296(5568):744-7. DOI: 10.1126/science.1069288. View

Tian M, Huitema E, da Cunha L, Torto-Alalibo T, Kamoun S . A Kazal-like extracellular serine protease inhibitor from Phytophthora infestans targets the tomato pathogenesis-related protease P69B. J Biol Chem. 2004; 279(25):26370-7. DOI: 10.1074/jbc.M400941200. View

Shabab M, Shindo T, Gu C, Kaschani F, Pansuriya T, Chintha R . Fungal effector protein AVR2 targets diversifying defense-related cys proteases of tomato. Plant Cell. 2008; 20(4):1169-83. PMC: 2390736. DOI: 10.1105/tpc.107.056325. View

Deslandes L, Olivier J, Peeters N, Feng D, Khounlotham M, Boucher C . Physical interaction between RRS1-R, a protein conferring resistance to bacterial wilt, and PopP2, a type III effector targeted to the plant nucleus. Proc Natl Acad Sci U S A. 2003; 100(13):8024-9. PMC: 164706. DOI: 10.1073/pnas.1230660100. View

10.

Greenbaum D, Arnold W, Lu F, Hayrapetian L, Baruch A, Krumrine J . Small molecule affinity fingerprinting. A tool for enzyme family subclassification, target identification, and inhibitor design. Chem Biol. 2002; 9(10):1085-94. DOI: 10.1016/s1074-5521(02)00238-7. View

11.

Leck J, Wiese T . Purification and characterization of the L-fucose transporter. Protein Expr Purif. 2004; 37(2):288-93. DOI: 10.1016/j.pep.2004.06.028. View

12.

Jones J, Dangl J . The plant immune system. Nature. 2006; 444(7117):323-9. DOI: 10.1038/nature05286. View

13.

Torto T, Li S, Styer A, Huitema E, Testa A, Gow N . EST mining and functional expression assays identify extracellular effector proteins from the plant pathogen Phytophthora. Genome Res. 2003; 13(7):1675-85. PMC: 403741. DOI: 10.1101/gr.910003. View

14.

Dangl J, Jones J . Plant pathogens and integrated defence responses to infection. Nature. 2001; 411(6839):826-33. DOI: 10.1038/35081161. View

15.

Kamoun S, van West P, de Jong A, de Groot K, Vleeshouwers V, Govers F . A gene encoding a protein elicitor of Phytophthora infestans is down-regulated during infection of potato. Mol Plant Microbe Interact. 1997; 10(1):13-20. DOI: 10.1094/MPMI.1997.10.1.13. View

16.

Dixon M, Golstein C, Thomas C, van der Biezen E, Jones J . Genetic complexity of pathogen perception by plants: the example of Rcr3, a tomato gene required specifically by Cf-2. Proc Natl Acad Sci U S A. 2000; 97(16):8807-14. PMC: 34016. DOI: 10.1073/pnas.97.16.8807. View

17.

Barrett A, Kembhavi A, Brown M, KIRSCHKE H, Knight C, Tamai M . L-trans-Epoxysuccinyl-leucylamido(4-guanidino)butane (E-64) and its analogues as inhibitors of cysteine proteinases including cathepsins B, H and L. Biochem J. 1982; 201(1):189-98. PMC: 1163625. DOI: 10.1042/bj2010189. View

18.

Kim H, Desveaux D, Singer A, Patel P, Sondek J, Dangl J . The Pseudomonas syringae effector AvrRpt2 cleaves its C-terminally acylated target, RIN4, from Arabidopsis membranes to block RPM1 activation. Proc Natl Acad Sci U S A. 2005; 102(18):6496-501. PMC: 1088372. DOI: 10.1073/pnas.0500792102. View

19.

Rooney H, Vant Klooster J, van der Hoorn R, Joosten M, Jones J, de Wit P . Cladosporium Avr2 inhibits tomato Rcr3 protease required for Cf-2-dependent disease resistance. Science. 2005; 308(5729):1783-6. DOI: 10.1126/science.1111404. View

20.

Rzychon M, Chmiel D, Stec-Niemczyk J . Modes of inhibition of cysteine proteases. Acta Biochim Pol. 2004; 51(4):861-73. View