Author: Irena Mačionienė
Internal reviewer: Lucas Morinière
Expert reviewer: WANTED!

Class: XopY
Family: XopY
Prototype: XOO1488 (Xanthomonas oryzae pv. oryzae; strain T7174)
GenBank ID: BAE68243.1 (281 aa)
RefSeq ID: WP_011408080.1 (281 aa)
3D structure: Unknown

XopY was discovered by screening the genome of X. oryzae pv. oryzae MAFF 311018 for proteins displaying a N-terminal amino acid pattern associated with T3S substrates in Pseudomonas syringae (Furutani et al., 2009). It has been primarily referred to as XOO1488, and then XopY (Song & Yang, 2010).

X. oryzae pv. oryzae transformants containing a plasmidic fusion of XopY (= XOO1488) with the Cya translocation reporter system were inoculated in tomato leaves. An increase of cAMP in the inflitrated areas was observed, thus revealing translocation of the fused protein into plant cells (Furutani et al., 2009).

XopY from X. oryzae pv. oryzae posseses a PIP and ‐10 box in the promoter region (TTCGB‐N₁₅ ‐TTCGB‐N_30–32 ‐YANNNT) (Yamaguchi et al., 2013a). Also, it was shown to be regulated by HrpX (Furutani et al., 2009).

qRT-PCR revealed that transcript levels of 15 out of 18 tested non-TAL effector genes (as well as the regulatory genes hrpG and hrpX), including xopY, were significantly reduced in the Xanthomonas oryzae pv. oryzae ΔxrvC mutant compared with those in the wild-type strain PXO99^A (Liu et al., 2016).

Transgenic rice plants expressing XOO1488 (Xoo1488-OX) were generated and inoculated with the T3SS-deficient hrpX mutant of Xoo, which is incapable of type III effector delivery. The Xoo hrpX mutant did not cause lesions in wild-type plant, presumably because of strong induction of PTI. In contrast, Xoo1488-OX plants had severe disease symptoms following infection with the Xoo hrpX mutant. Bacterial populations of the Xoo hrpX mutant in Xoo1488-OX leaves were higher than in wild-type plants. The growth of wild-type isolate Xoo MAFF311018 in Xoo1488-OX plants also increased significantly over its growth in wild-type plants. Thus, it is likely that XopY inhibits PTI induced by infection of Xoo hrpX mutant. However, it was noted that XopY knockout strain did not exhibit any defect in virulence (Yamaguchi et al., 2013a). XopY was also shown to inhibit chitin-induced expression of defense-related genes (Yamaguchi et al., 2013b). XopY of X. oryzae pv. oryzicola was also shown to trigger HR in non-host Nicothiana benthamiana plants (Li et al., 2015).

Unknown.

Unknown.

XopY was demonstrated to target OsRLCK185. Expression of XopY in rice cells compromises OsRLCK185-mediated immune responses, which is consistent with the fact that Xoo1488 inhibits trans-phosphorylation of the activation domain of OsRLCK185 by OsCERK1. Interestingly, XopY is phosphorylated by OsRLCK185, suggesting that modification of XopY in host cell may affect their virulent activity (Yamaguchi et al., 2013b).

Yes (e.g., X. oryzae, X. translucens, X. vasicola).

No.

Furutani A, Takaoka M, Sanada H, Noguchi Y, Oku T, Tsuno K, Ochiai H, Tsuge S (2009). Identification of novel type III secretion effectors in Xanthomonas oryzae pv. oryzae. Mol. Plant Microbe Interact. 22: 96-106. DOI: 10.1094/MPMI-22-1-0096

Li S, Wang Y, Wang S, Fang A, Wang J, Liu L, Zhang K, Mao Y, Sun W (2015). The type III effector AvrBs2 in Xanthomonas oryzae pv. oryzicola suppresses rice immunity and promotes disease development. Mol. Plant Microbe Interact. 28: 869-880. DOI: 10.1094/MPMI-10-14-0314-R

Liu Y, Long J, Shen D, Song C (2016). Xanthomonas oryzae pv. oryzae requires H-NS-family protein XrvC to regulate virulence during rice infection. FEMS Microbiol. Lett. 363: fnw067. DOI: 10.1093/femsle/fnw067

Song C, Yang B (2010). Mutagenesis of 18 type III effectors reveals virulence function of XopZ_PXO99 in Xanthomonas oryzae pv. oryzae. Mol. Plant Microbe Interact. 23: 893-902. DOI: 10.1094/MPMI-23-7-0893

Yamaguchi K, Nakamura Y, Ishikawa K, Yoshimura Y, Tsuge S, Kawasaki T (2013a). Suppression of rice immunity by Xanthomonas oryzae type III effector Xoo2875. Biosci. Biotechnol. Biochem. 77: 796-801. DOI: 10.1271/bbb.120929

Yamaguchi K, Yamada K, Ishikawa K, Yoshimura S, Hayashi N, Uchihashi K, Ishihama N, Kishi-Kaboshi M, Takahashi A, Tsuge S, Ochiai H, Tada Y, Shimamoto K, Yoshioka H, Kawasaki T (2013b). A receptor-like cytoplasmic kinase targeted by a plant pathogen effector is directly phosphorylated by the chitin receptor and mediates rice immunity. Cell Host Microbe 13: 347-357. DOI: 10.1016/j.chom.2013.02.007

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