====== XopV ======
Author: Coline Sciallano\\
Internal reviewer: [[https://www.researchgate.net/profile/Gabor_Rakhely|Gábor Rákheli]]\\
Expert reviewer: Seiji Tsuge
Class: XopV\\
Family: XopV\\
Prototype: XOO3803 (//Xanthomonas oryzae// pv. //oryzae//; strain MAFF 311018)\\
RefSeq ID: [[https://www.ncbi.nlm.nih.gov/protein/WP_027703842.1|WP_027703842.1]] (331 aa)\\
3D structure: Unknown
===== Biological function =====
=== How discovered? ===
XopV was discovered via genome-wide screening for effector candidates in //X. oryzae// pv. //oryzae// (//Xoo//) strain MAFF 311018 in accordance with three criteria: i) ORF encoding proteins homologous to effectors of //P. syringae// strains and //X. campestris// pv. //vesicatoria//, ii) HrpX regulons preceded by two cis elements (Plant Induced Promoter, PIP; and -10 box-like motif) or iii) proteins with an N-terminal amino acid composition similar to known effectors (more than 10% of Ser in the first 50 amino aa, no Asp or Glu residues in the first 12 aa, and an aliphatic amino acid or Pro at the third or fourth position) (Furutani //et al//., 2009).
=== (Experimental) evidence for being a T3E ===
TT3S-dependent translocation of XopV has been shown by a calmodulin-dependent adenylate cyclase reporter assay (Furutani //et al//., 2009).
=== Regulation ===
//xopV// was shown to contain the PIP-box motif in their promoter region, and the expression was found to be regulated by HrpX using a β -glucuronidase (GUS) reporter assay in //hrp//-inducing medium (Tsuge //et al.//, 2005).
=== Phenotypes ===
Popov //et al.// (2016) reported that //Xanthomonas euvesicatoria// XopV inhibits flg22-triggered immunity in //Arabidopsis thaliana //using apathogen-free cell system for transient gene expression analysis.
An individual mutant for //xopV// in Xoo PXO99A did not show reduced virulence on rice varieties IR24 (Song & Yang, 2010) and Kitaake (Long //et al.//, 2018). But interestingly, a significant reduction in lesion length on Kitaake was observed when inoculated with a triple mutant of PXO99A for //xopV//, //xopZ// (two copies) and //xopN// although no differences in virulence were observed when comparing the WT PXO99A strain and individual or double mutants for each of these effector genes (//xopV//, //xopZ//, //xopN//). Three effectors were shown to be able to suppress the peptidoglycan-triggered MAPK activation when individually expressed in rice cells.The results indicate that XopV, along with XopZ and XopN, collectively and redundantly contributes virulence in rice (Long //et al.//, 2018).
//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. Five effectors, XopV, XopU, XopP, XopG and AvrBs2, could individually suppress these immune responses, which suggests a complex interplay of //Xanthomonas //effectors in suppression of not only pathogen-triggered immunity but also effector-triggered immunity to promote virulence on rice (Deb //et al.//, 2020).
=== Localization ===
Unknown.
=== Enzymatic function ===
Unknown.
=== Interaction partners ===
Unknown.
===== Conservation =====
=== In xanthomonads ===
Yes, examples: //X. campestris//, //X. euvesicatoria//, //X. oryzae//, //X. vasicola//, //X. phaseoli//, //X. citri//, //X. axonopodis//.
=== In other plant pathogens/symbionts ===
Yes, examples: //Pseudomonas cissicola//, //Ralstonia solanacearum//, //Acidovorax citrulli//.
===== References =====
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. 104: 332-350. DOI: [[https://doi.org/10.1111/tpj.14924|10.1111/tpj.14924]]
Furutani A, Takaoka M, Sanada H, Noguchi Y, Oku T, Tsuno K, Tsuge S (2009). Identification of novel type III secretion effectors in //Xanthomonas oryzae// pv. //oryzae//. Mol. Plant Microbe Interact. 22: 96-106. DOI: [[https://doi.org/10.1094/mpmi-22-1-0096|10.1094/mpmi-22-1-0096]]
Long J, Song C, Yan F, Zhou J, Zhou H, Yang B (2018). Non-TAL effectors from //Xanthomonas oryzae// pv. //oryzae// suppress peptidoglycan-triggered MAPK activation in rice. Front. Plant Sci. 12: 1857. DOI: [[https://doi.org/10.3389/fpls.2018.01857|10.3389/fpls.2018.01857]]
Popov G, Fraiture M, Brunner B, Sessa G (2016). Multiple //Xanthomonas euvesicatoria// type III effectors inhibit flg22-triggered immunity. Mol. Plant Microbe Interact. 29:651–660. DOI:[[https://doi.org/10.1094/MPMI-07-16-0137-R|10.1094/MPMI-07-16-0137-R]]
Song C, Yang B (2010). Mutagenesis of 18 type III effectors reveals virulence function of XopZPXO99 in //Xanthomonas oryzae// pv. //oryzae//. Mol. Plant Microbe Interact. 23: 893-902. DOI: [[https://doi.org/10.1094/mpmi-23-7-0893|10.1094/mpmi-23-7-0893]]
Tsuge S, Terashima S, Furutani A, Ochiai H, Oku T, Tsuno K, Kaku H, Kubo Y (2005). Effects on promoter activity of base substitutions in the //cis//-acting regulatory element of HrpXo regulons in //Xanthomonas oryzae //pv. //oryzae//. J. Bacteriology 187: 2308-2314.DOI: [[https://www.doi.org/10.1128/JB.187.7.2308-2314.2005|10.1128/JB.187.7.2308-2314.2005]]