scholarly journals Establishment of an inducing medium for type III effector secretion in Xanthomonas campestris pv. campestris

2013 ◽  
Vol 44 (3) ◽  
pp. 945-952 ◽  
Author(s):  
Guo-Feng Jiang ◽  
Bo-Le Jiang ◽  
Mei Yang ◽  
San Liu ◽  
Jiao Liu ◽  
...  
Keyword(s):  
Xanthomonas Campestris ◽  
Type Iii Effector ◽  
Type Iii ◽  
Effector Secretion ◽  
Xanthomonas Campestris Pv Campestris

scholarly journals Characterization, Phylogeny, and Genome Analyses of Nonpathogenic Xanthomonas campestris Strains Isolated from Brassica Seeds

2020 ◽  
Vol 110 (5) ◽  
pp. 981-988 ◽  
Author(s):  
Yung-An Lee ◽  
Pei-Yu Yang ◽  
Shau-Chang Huang
Keyword(s):  
Type Iii Secretion ◽  
Xanthomonas Campestris ◽  
Pathogenicity Island ◽  
Whole Genome Sequence ◽  
Effector Protein ◽  
Type Iii Effector ◽  
Type Iii ◽  
Effector Genes ◽  
Genome Analyses ◽  
Xanthomonas Campestris Pv Campestris

Xanthomonads were detected by using the Xan-D(CCF) medium from the brassica seeds, and their pathogenicity was determined by plant inoculation tests. It was found that some seed lots were infested with Xanthomonas campestris pv. campestris, some with X. campestris pv. raphani, and some with nonpathogenic xanthomonads. The nonpathogenic xanthomonad strains were identified as X. campestris, and the multilocus sequence analysis showed that the nonpathogenic X. campestris strains were grouped together with pathogenic X. campestris, but not with nonpathogenic strains of X. arboricola. In addition, all isolated X. campestris pv. campestris and X. campestris pv. raphani strains were positive in the hrpF-PCR, but the nonpathogenic strains were negative. It was further found that nonpathogenic X. campestris strain nE1 does not contain the entire pathogenicity island (hrp gene cluster; type III secretion system) and all type III effector protein genes based on the whole genome sequence analyses. The nonpathogenic X. campestris strain nE1 could acquire the entire pathogenicity island from the endemic X. campestris pv. campestris and X. campestris pv. raphani strains by conjugation, but type III effector genes were not cotransferred. The studies showed that the nonpathogenic X. campestris strains indeed exist on the brassica seeds, but it could be differentiated by the PCR assays on the hrp and type III effector genes. Nevertheless, the nonpathogenic X. campestris strains cannot be ignored because they may be potential gene resources to increase genetic diversity in the endemic pathogenic X. campestris pv. campestris and X. campestris pv. raphani strains.

scholarly journals The Xanthomonas type-III effector protein XopS stabilizes CaWRKY40a to regulate defense hormone responses and preinvasion immunity in pepper (Capsicum annuum)

2021 ◽  
Author(s):  
Margot Raffeiner ◽  
Suayib Üstün ◽  
Tiziana Guerra ◽  
Daniela Spinti ◽  
Maria Fitzner ◽  
...  
Keyword(s):  
Gene Expression ◽  
Xanthomonas Campestris ◽  
Stomatal Closure ◽  
Ectopic Expression ◽  
Defense Responses ◽  
Dependent Manner ◽  
Plant Tolerance ◽  
Defense Gene Expression ◽  
Type Iii Effector ◽  
Type Iii

A critical component of plant immunity against invading pathogens is the rapid transcriptional reprogramming of the attacked cell to minimize virulence. Many adapted plant bacterial pathogens use type III effector (T3E) proteins to interfere with plant defense responses, including the induction of immunity genes. The elucidation of effector function is essential to understanding bacterial pathogenesis. Here, we show that XopS, a T3E of Xanthomonas campestris pv. vesicatoria (Xcv), interacts with and inhibits the proteasomal degradation of the transcriptional regulator of defense gene expression WRKY40. Virus-induced gene silencing of WRKY40 in pepper enhanced plant tolerance towards Xcv infection, indicating it represses immunity. Stabilization of WRKY40 by XopS reduces the expression of its targets including salicylic acid (SA)-responsive genes and the jasmonic acid (JA) signaling repressor JAZ8. Xcv bacteria lacking XopS display significantly reduced virulence when surface inoculated onto susceptible pepper leaves. XopS delivery by Xcv, as well as ectopic expression of XopS in Arabidopsis or Nicotiana benthamiana prevented stomatal closure in response to bacteria and biotic elicitors in a WRKY40 dependent manner. This suggests that XopS interferes with preinvasion as well as with apoplastic defense by manipulating WRKY40 stability and gene expression eventually altering phytohormone crosstalk to promote pathogen proliferation.

scholarly journals Identification of Six Type III Effector Genes with the PIP Box in Xanthomonas campestris pv. campestris and Five of Them Contribute Individually to Full Pathogenicity

2009 ◽  
Vol 22 (11) ◽  
pp. 1401-1411 ◽  
Author(s):  
Wei Jiang ◽  
Bo-Le Jiang ◽  
Rong-Qi Xu ◽  
Jun-Ding Huang ◽  
Hong-Yu Wei ◽  
...  
Keyword(s):  
Xanthomonas Campestris ◽  
Regulatory Element ◽  
Regulatory Protein ◽  
Plant Cells ◽  
Dependent Manner ◽  
Type Iii ◽  
Effector Genes ◽  
A Genome ◽  
Hrp Genes ◽  
Xanthomonas Campestris Pv Campestris

Xanthomonas campestris pv. campestris is the pathogen of black rot of cruciferous plants. The pathogenicity of the pathogen depends on the type III secretion system (T3SS) that translocates directly effector proteins into plant cells, where they play important roles in the molecular interaction between the pathogen and its hosts. The T3SS of Xanthomonas spp. is encoded by a cluster of hypersensitive response and pathogenicity (hrp) genes. It has been demonstrated that the expression of hrp genes and some type III secreted (T3S)-effector genes is coactivated by the key hrp regulatory protein HrpX. The regulation by HrpX can be mediated by the binding of HrpX protein to a cis-regulatory element named the plant-inducible promoter (PIP) box present in the promoter region of HrpX-regulated genes. A genome screen revealed that X. campestris pv. campestris 8004 possesses 56 predicted genes with the PIP box. Nine of these genes have been shown to encode T3S effectors, Hrp, and Hrp-associated proteins. In this study, we employed an established T3S effector translocation assay with the hypersensitive-reaction-inducing domain of X. campestris pv. campestris AvrBs1 as a reporter to characterize the remaining 47 genes with the PIP box and showed that 6 of them, designated as XopXccE1, XopXccP, XopXccQ, XopXccR1, XopXccLR, and AvrXccB, harbor a functional translocation signal in their N-terminal regions, indicating that they are T3S effectors of X. campestris pv. campestris. We provided evidence to demonstrate that all these effectors are expressed in an HrpX-dependent manner and their translocation into plant cells relies on the translocon protein HrpF and the chaperone HpaB. Mutational analyses demonstrated that all these effectors, except AvrXccB, are individually required for full virulence and growth of X. campestris pv. campestris in the host plant Chinese radish.

The type III secretion effector XopXccN of Xanthomonas campestris pv. campestris is required for full virulence

2008 ◽  
Vol 159 (3) ◽  
pp. 216-220 ◽  
Author(s):  
Bo-Le Jiang ◽  
Yong-Qiang He ◽  
Wei-Jian Cen ◽  
Hong-Yu Wei ◽  
Guo-Feng Jiang ◽  
...  
Keyword(s):  
Type Iii Secretion ◽  
Xanthomonas Campestris ◽  
Type Iii ◽  
Type Iii Secretion Effector ◽  
Xanthomonas Campestris Pv Campestris

scholarly journals Xanthomonas campestris pv. vesicatoria Effector AvrBsT Induces Cell Death in Pepper, but Suppresses Defense Responses in Tomato

2010 ◽  
Vol 23 (8) ◽  
pp. 1069-1082 ◽  
Author(s):  
Nak Hyun Kim ◽  
Hyong Woo Choi ◽  
Byung Kook Hwang
Keyword(s):  
Xanthomonas Campestris ◽  
Marker Gene ◽  
Defense Responses ◽  
Gene Expressions ◽  
Callose Deposition ◽  
Tomato Plants ◽  
Type Iii Effector ◽  
Type Iii ◽  
Pepper Leaves ◽  
Pepper Plants

A type III effector protein, AvrBsT, is secreted into plant cells from Xanthomonas campestris pv. vesicatoria Bv5-4a, which causes bacterial spot disease on pepper (Capsicum annuum) and tomato (Solanum lycopersicum). To define the function and recognition of AvrBsT in the two host plants, avrBsT was introduced into the virulent pepper strain X. campestris pv. vesicatoria Ds1. Expression of AvrBsT in Ds1 rendered the strain avirulent to pepper plants. Infection of pepper leaves with Ds1 (avrBsT) expressing AvrBsT but not with near-isogenic control strains triggered a hypersensitive response (HR) accompanied by strong H2O2 generation, callose deposition, and defense-marker gene expressions. Mutation of avrBsT, however, compromised HR induction by X. campestris pv. vesicatoria Bv5-4a, suggesting its avirulence function in pepper plants. In contrast, AvrBsT acted as a virulence factor in tomato plants. Growth of strains Ds1 (avrBsT) and Bv5-4a ΔavrBsT was significantly enhanced and reduced, respectively, in tomato leaves. X. campestris pv. vesicatoria-expressed AvrBsT also significantly compromised callose deposition and defense-marker gene expression in tomato plants. Together, these results suggest that the X. campestris pv. vesicatoria type III effector AvrBsT is differentially recognized by pepper and tomato plants.

Multiple Xanthomonas campestris pv. campestris 8004 type III effectors inhibit immunity induced by flg22

Planta ◽  
2020 ◽  
Vol 252 (5) ◽  
Author(s):  
Yan Huang ◽  
Tongqi Li ◽  
Ting Xu ◽  
Zizhong Tang ◽  
Jingya Guo ◽  
...  
Keyword(s):  
Xanthomonas Campestris ◽  
Type Iii Effectors ◽  
Type Iii ◽  
Xanthomonas Campestris Pv Campestris

scholarly journals The Xanthomonas Type III Effector Protein AvrBs3 Modulates Plant Gene Expression and Induces Cell Hypertrophy in the Susceptible Host

2002 ◽  
Vol 15 (7) ◽  
pp. 637-646 ◽  
Author(s):  
Eric Marois ◽  
Guido Van den Ackerveken ◽  
Ulla Bonas
Keyword(s):  
Gene Expression ◽  
Xanthomonas Campestris ◽  
Poly Merase Chain Reaction ◽  
Effector Protein ◽  
Polymorphism Analysis ◽  
Dependent Manner ◽  
Susceptible Host ◽  
Type Iii Effector ◽  
Nuclear Localization Signals ◽  
Type Iii

Xanthomonas campestris pv. vesicatoria bacteria expressing the type III effector protein AvrBs3 induce a hypersensitive response in pepper plants carrying the resistance gene Bs3. Here, we report that infection of susceptible pepper and tomato plants leads to an AvrBs3-dependent hypertrophy of the mesophyll tissue. Agrobacterium-mediated transient expression of the avrBs3 gene in tobacco and potato plants resulted in a similar phenotype. Induction of hypertrophy was shown to depend on the repeat region, nuclear localization signals, and acidic transcription activation domain (AAD) of AvrBs3, suggesting that the effector modulates the host's transcriptome. To search for host genes regulated by AvrBs3 in an AAD-dependent manner, we performed a cDNA-amplified fragment length polymorphism analysis of pepper mRNA populations. Thirteen AvrBs3-induced transcripts were identified and confirmed by reverse transcriptase-poly-merase chain reaction. Sequence analysis revealed homologies to auxin-induced and expansinlike genes, which play a role in cell enlargement. These results suggest that some of the AvrBs3-induced genes may be involved in hypertrophy development and that xanthomonads possess type III effectors that steer host gene expression.

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