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Molecular Diagnosis and Diversity for Regulated Xanthomonas

Bacterial virulence factors

Plant resistance genes

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This DokuWiki is based upon work from COST Action CA16107 EuroXanth, supported by COST (European Cooperation in Science and Technology)

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Author: Camila Ferdandes
Internal reviewer: Leonor Martins
Expert reviewer: Neha Potnis

Class: XopG
Family: XopG1, XopG2, XopG3
Prototype: XopG (Xanthomonas euvesicatoria pv. euvesicatoria, ex Xanthomonas campestris pv. vesicatoria; strain 85-10)
RefSeq ID: CAJ22929 (213 aa)
3D structure: Q3BW34 (homology model)

Biological function

How discovered?

XopG was identified based on homology searches using TBLASTN analysis. Known T3E proteins from plant and animal pathogens were used as query against all contigs of the draft genomes of X. vesicatoria, X. gardneri and X. perforans with e-value of 10-5 (Potnis et al., 2011).

(Experimental) evidence for being a T3E

The T3SS-dependent translocation evidence for XopG protein was confirmed using the AvrBs2 reporter gene assay (Thieme, 2006; Potnis et al., 2011).


XopG belongs to translocation class B and is still translocated in the absence of HpaB, being constitutively expressed (Schulze et al. 2012). XopG was identified as part of the putative HrpX regulon in X. campestris pv. campestris ATCC339138 (da Silva et al., 2002; White et al., 2009).


A deletion of xopG did not display differences in the induction of disease symptoms or hypersensibility response. XopG trigger cell death in different Solanaceae, including Nicotiana tabacum (White et al., 2009). XopG could be an essential pathogenicity factor in pepper (Potnis et al., 2011).

Agrobacterium-mediated transient expression of both XopQ and XopX in rice cells resulted in induction of rice immune responses, which were not observed when either protein was individually expressed. A screen for Xanthomonas effectors which can suppress XopQ-XopX induced rice immune responses, led to the identification of five effectors, namely XopU, XopV, XopP, XopG and AvrBs2, that could individually suppress these immune responses. These results suggest a complex interplay of Xanthomonas T3SS effectors in suppression of both pathogen-triggered immunity and effector-triggered immunity to promote virulence on rice (Deb et al., 2020).


Confocal laser scanning microscopy revealed a localization of XopG::GFP exclusively to the plant cell nucleus (Schulze et al. 2012).

Enzymatic function

XopG is a member of the HopH family from Pseudomonas syringae and encodes a protein with a putative zinc protease binding motif, typical of the zinc metalloproteases of the M27 family (similar to a clostridial toxin, botulinum toxin A from Clostridium botulinum) (Thieme, 2006; White et al., 2009; Schulze et al., 2012).

Interaction partners



In xanthomonads

Yes (e.g., X. arboricola, X. campestris, X. citri, X. euvesicatoria, X. gardneri, X. oryzae, X. translucens, X. vesicatoria).

In other plant pathogens/symbionts

Yes (Ralstonia solanacearum, Pseudomonas spp., Acidovorax citrulli).


da Silva AC, Ferro JA, Reinach FC, Farah CS, Furlan LR, Quaggio RB, Monteiro-Vitorello CB, Van Sluys MA, Almeida NF, Alves LM, do Amaral AM, Bertolini MC, Camargo LE, Camarotte G, Cannavan F, Cardozo J, Chambergo F, Ciapina LP, Cicarelli RM, Coutinho LL, Cursino-Santos JR, El-Dorry H, Faria JB, Ferreira AJ, Ferreira RC, Ferro MI, Formighieri EF, Franco MC, Greggio CC, Gruber A, Katsuyama AM, Kishi LT, Leite RP, Lemos EG, Lemos MV, Locali EC, Machado MA, Madeira AM, Martinez-Rossi NM, Martins EC, Meidanis J, Menck CF, Miyaki CY, Moon DH, Moreira LM, Novo MT, Okura VK, Oliveira MC, Oliveira VR, Pereira HA, Rossi A, Sena JA, Silva C, de Souza RF, Spinola LA, Takita MA, Tamura RE, Teixeira EC, Tezza RI, Trindade dos Santos M, Truffi D, Tsai SM, White FF, Setubal JC, Kitajima JP (2002). Comparison of the genomes of two Xanthomonas pathogens with differing host specificities. Nature 417: 459-463. DOI: 10.1038/417459a

Deb S, Ghosh P, Patel HK, Sonti RV (2020). Interaction of the Xanthomonas effectors XopQ and XopX results in induction of rice immune responses. Plant J., in press. DOI: 10.1111/tpj.14924

Potnis N, Krasileva K, Chow V, Almeida NF, Patil PB, Ryan RP, Sharlach M, Behlau F, Dow JM, Momol MT, White FF, Preston JF, Vinatzer BA, Koebnik R, Setubal JC, Norman DJ, Staskawicz BJ, Jones JB (2011). Comparative genomics reveals diversity among xanthomonads infecting tomato and pepper. BMC Genomics 12: 146. DOI: 10.1186/1471-2164-12-146

Schulze S, Kay S, Büttner D, Egler M, Eschen-Lippold L, Hause G, Krüger A, Lee J, Müller O, Scheel D, Szczesny R, Thieme F, Bonas U (2012). Analysis of new type III effectors from Xanthomonas uncovers XopB and XopS as suppressors of plant immunity. New Phytol. 195: 894-911. DOI: 10.1111/j.1469-8137.2012.04210.x

Thieme F (2006). Genombasierte Identifizierung neuer potentieller Virulenzfaktoren von Xanthomonas campestris pv. vesicatoria. Doctoral Thesis, Martin-Luther-Universität Halle-Wittenberg, Germany. PDF:

Thieme F, Koebnik R, Bekel T, Berger C, Boch J, Büttner D, Caldana C, Gaigalat L, Goesmann A, Kay S, Kirchner O, Lanz C, Linke B, McHardy AC, Meyer F, Mittenhuber G, Nies DH, Niesbach-Klösgen U, Patschkowski T, Rückert C, Rupp O, Schneiker S, Schuster SC, Vorhölter FJ, Weber E, Pühler A, Bonas U, Bartels D, Kaiser O (2005). Insights into genome plasticity and pathogenicity of the plant pathogenic bacterium Xanthomonas campestris pv. vesicatoria revealed by the complete genome sequence. J. Bacteriol. 187: 7254-7266. DOI: 10.1128/JB.187.21.7254-7266.2005

White FF, Potnis N, Jones JB, Koebnik R (2009). The type III effectors of Xanthomonas. Mol. Plant Pathol.10: 749-766. DOI: 10.1111/j.1364-3703.2009.00590.x

bacteria/t3e/xopg.txt · Last modified: 2020/12/02 22:58 by jfpothier