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Huang J, Zhou H, Zhou M, Li N, Jiang B, He Y. Functional Analysis of Type III Effectors in Xanthomonas campestris pv. campestris Reveals Distinct Roles in Modulating Arabidopsis Innate Immunity. Pathogens 2024; 13:448. [PMID: 38921746 PMCID: PMC11206781 DOI: 10.3390/pathogens13060448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 05/19/2024] [Accepted: 05/23/2024] [Indexed: 06/27/2024] Open
Abstract
Xanthomonas campestris pv. campestris (Xcc) is a significant phytopathogen causing black rot disease in crucifers. Its virulence relies heavily on the type III secretion system (T3SS), facilitating effector translocation into plant cells. The type III effectors (T3Es) disrupt cellular processes, promoting pathogen proliferation. However, only a few T3Es from Xcc have been thoroughly characterized. In this study, we further investigated two effectors using the T3Es-deficient mutant and the Arabidopsis protoplast system. XopE2Xcc triggers Arabidopsis immune responses via an unidentified activator of the salicylic acid (SA) signaling pathway, whereas XopLXcc suppresses the expression of genes associated with patterns-triggered immunity (PTI) and the SA signaling pathway. These two effectors exert opposing effects on Arabidopsis immune responses. Additionally, we examined the relationship between the specific domains and functions of these two effector proteins. Our findings demonstrate that the N-myristoylation motif and N-terminal domain are essential for the subcellular localization and virulence of XopE2Xcc and XopLXcc, respectively. These novel insights enhance our understanding of the pathogenic mechanisms of T3Es and contribute to developing effective strategies for controlling bacterial disease.
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Affiliation(s)
- Jing Huang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530005, China; (J.H.); (B.J.)
| | - Hao Zhou
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530005, China; (J.H.); (B.J.)
- Guangxi Key Laboratory for Polysaccharide Materials and Modifications, Guangxi Minzu University, Nanning 530006, China
| | - Min Zhou
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530005, China; (J.H.); (B.J.)
| | - Nana Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530005, China; (J.H.); (B.J.)
| | - Bole Jiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530005, China; (J.H.); (B.J.)
| | - Yongqiang He
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530005, China; (J.H.); (B.J.)
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2
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Fricke LC, Lindsey ARI. Identification of Parthenogenesis-Inducing Effector Proteins in Wolbachia. Genome Biol Evol 2024; 16:evae036. [PMID: 38530785 PMCID: PMC11019157 DOI: 10.1093/gbe/evae036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 02/12/2024] [Accepted: 02/18/2024] [Indexed: 03/28/2024] Open
Abstract
Bacteria in the genus Wolbachia have evolved numerous strategies to manipulate arthropod sex, including the conversion of would-be male offspring to asexually reproducing females. This so-called "parthenogenesis induction" phenotype can be found in a number of Wolbachia strains that infect arthropods with haplodiploid sex determination systems, including parasitoid wasps. Despite the discovery of microbe-mediated parthenogenesis more than 30 yr ago, the underlying genetic mechanisms have remained elusive. We used a suite of genomic, computational, and molecular tools to identify and characterize two proteins that are uniquely found in parthenogenesis-inducing Wolbachia and have strong signatures of host-associated bacterial effector proteins. These putative parthenogenesis-inducing proteins have structural homology to eukaryotic protein domains including nucleoporins, the key insect sex determining factor Transformer, and a eukaryotic-like serine-threonine kinase with leucine-rich repeats. Furthermore, these proteins significantly impact eukaryotic cell biology in the model Saccharomyces cerevisiae. We suggest that these proteins are parthenogenesis-inducing factors and our results indicate that this would be made possible by a novel mechanism of bacterial-host interaction.
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Affiliation(s)
- Laura C Fricke
- Department of Entomology, University of Minnesota, St. Paul, MN 55108, USA
| | - Amelia R I Lindsey
- Department of Entomology, University of Minnesota, St. Paul, MN 55108, USA
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3
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Lauber E, González-Fuente M, Escouboué M, Vicédo C, Luneau JS, Pouzet C, Jauneau A, Gris C, Zhang ZM, Pichereaux C, Carrère S, Deslandes L, Noël LD. Bacterial host adaptation through sequence and structural variations of a single type III effector gene. iScience 2024; 27:109224. [PMID: 38439954 PMCID: PMC10909901 DOI: 10.1016/j.isci.2024.109224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 12/02/2023] [Accepted: 02/08/2024] [Indexed: 03/06/2024] Open
Abstract
Molecular mechanisms underlying quantitative variations of pathogenicity remain elusive. Here, we identified the Xanthomonas campestris XopJ6 effector that triggers disease resistance in cauliflower and Arabidopsis thaliana. XopJ6 is a close homolog of the Ralstoniapseudosolanacearum PopP2 YopJ family acetyltransferase. XopJ6 is recognized by the RRS1-R/RPS4 NLR pair that integrates a WRKY decoy domain mimicking effector targets. We identified a XopJ6 natural variant carrying a single residue substitution in XopJ6 WRKY-binding site that disrupts interaction with WRKY proteins. This mutation allows XopJ6 to evade immune perception while retaining some XopJ6 virulence functions. Interestingly, xopJ6 resides in a Tn3-family transposon likely contributing to xopJ6 copy number variation (CNV). Using synthetic biology, we demonstrate that xopJ6 CNV tunes pathogen virulence on Arabidopsis through gene dosage-mediated modulation of xopJ6 expression. Together, our findings highlight how sequence and structural genetic variations restricted at a particular effector gene contribute to bacterial host adaptation.
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Affiliation(s)
- Emmanuelle Lauber
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, F-31326 Castanet-Tolosan, France
| | - Manuel González-Fuente
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, F-31326 Castanet-Tolosan, France
| | - Maxime Escouboué
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, F-31326 Castanet-Tolosan, France
| | - Céline Vicédo
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, F-31326 Castanet-Tolosan, France
| | - Julien S. Luneau
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, F-31326 Castanet-Tolosan, France
| | - Cécile Pouzet
- TRI-FRAIB Imaging Platform Facilities, FRAIB, Université de Toulouse, CNRS, UPS, 31320 Castanet-Tolosan, France
| | - Alain Jauneau
- TRI-FRAIB Imaging Platform Facilities, FRAIB, Université de Toulouse, CNRS, UPS, 31320 Castanet-Tolosan, France
| | - Carine Gris
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, F-31326 Castanet-Tolosan, France
| | - Zhi-Min Zhang
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou 510632, China
| | - Carole Pichereaux
- Fédération de Recherche Agrobiosciences, Interactions et Biodiversité (FRAIB), Université de Toulouse, CNRS, Université de Toulouse III - Paul Sabatier (UT3), Auzeville-Tolosane, France
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, Université de Toulouse III - Paul Sabatier (UT3), Toulouse, France
- Infrastructure nationale de protéomique, ProFI, FR 2048, Toulouse, France
| | - Sébastien Carrère
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, F-31326 Castanet-Tolosan, France
| | - Laurent Deslandes
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, F-31326 Castanet-Tolosan, France
| | - Laurent D. Noël
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, F-31326 Castanet-Tolosan, France
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4
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Fricke LC, Lindsey ARI. Identification of parthenogenesis-inducing effector proteins in Wolbachia. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.01.569668. [PMID: 38076953 PMCID: PMC10705499 DOI: 10.1101/2023.12.01.569668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2023]
Abstract
Bacteria in the genus Wolbachia have evolved numerous strategies to manipulate arthropod sex, including the conversion of would-be male offspring to asexually reproducing females. This so-called "parthenogenesis-induction" phenotype can be found in a number of Wolbachia strains that infect arthropods with haplodiploid sex determination systems, including parasitoid wasps. Despite the discovery of microbe-mediated parthenogenesis more than 30 years ago, the underlying genetic mechanisms have remained elusive. We used a suite of genomic, computational, and molecular tools to identify and characterize two proteins that are uniquely found in parthenogenesis-inducing Wolbachia and have strong signatures of host-associated bacterial effector proteins. These putative parthenogenesis-inducing proteins have structural homology to eukaryotic protein domains including nucleoporins, the key insect sex-determining factor Transformer, and a eukaryotic-like serine-threonine kinase with leucine rich repeats. Furthermore, these proteins significantly impact eukaryotic cell biology in the model, Saccharomyces cerevisiae. We suggest these proteins are parthenogenesis-inducing factors and our results indicate this would be made possible by a novel mechanism of bacterial-host interaction.
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Affiliation(s)
- Laura C Fricke
- Department of Entomology, University of Minnesota, St. Paul, Minnesota, 55108
| | - Amelia RI Lindsey
- Department of Entomology, University of Minnesota, St. Paul, Minnesota, 55108
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Li JB, Xiong LT, Lu YR, Zhang YQ, Xu XL, Wang HH, Deng X, Hu XH, Cui ZN. Novel pyrimidin-4-one derivatives as potential T3SS inhibitors against Xanthomonas campestris pv. campestris. PEST MANAGEMENT SCIENCE 2023; 79:3666-3675. [PMID: 37184259 DOI: 10.1002/ps.7545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 05/10/2023] [Accepted: 05/11/2023] [Indexed: 05/16/2023]
Abstract
BACKGROUND Cruciferous black rot is caused by Xanthomonas campestris pv. campestris (Xcc) infection and is a widespread disease worldwide. Excessive and repeated use of bactericide is an important cause of the development of bacterial resistance. It is imperative to take new approaches to screening compounds that target virulence factors rather than kill bacterial pathogens. The type III secretion system (T3SS) invades a variety of cells by transporting virulence effector factors into the cytoplasm and is an attractive antitoxic target. Toward the search of new T3SS inhibitors, an alternative series of novel pyrimidin-4-one derivatives were designed and synthesized and assessed for their effect in blocking the virulence. RESULTS All of the target compounds were characterized by proton (1 H) nuclear magnetic resonance (NMR), carbon-13 (13 C) NMR, fluorine-19 (19 F) NMR and high-resolution mass spectrometry (HRMS). All compounds were evaluated using high-throughput screening systems against Xcc. The results of the biological activity test revealed that the compound SPF-9 could highly inhibit the activity of xopN gene promoter and the hypersensitivity (HR) of tobacco without affecting bacterial growth. Moreover, messenger RNA (mRNA) level measurements showed that compound SPF-9 inhibited the expression of some representative genes (hrp/hrc genes). Compound SPF-9 weakened the pathogenicity of Xcc to Raphanus sativus L. CONCLUSION Compound SPF-9 has good potential for further development as a novel T3SS inhibitor against Xcc. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Jia-Bao Li
- National Key Laboratory of Green Pesticide, Integrative Microbiology Research Center, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, China
| | - Lan-Tu Xiong
- National Key Laboratory of Green Pesticide, Integrative Microbiology Research Center, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, China
| | - Yan-Rong Lu
- National Key Laboratory of Green Pesticide, Integrative Microbiology Research Center, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, China
| | - Yu-Qing Zhang
- National Key Laboratory of Green Pesticide, Integrative Microbiology Research Center, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, China
| | - Xiao-Li Xu
- Instrumental Analysis and Research Center, South China Agricultural University, Guangzhou, China
| | - Hai-Hong Wang
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, China
| | - Xin Deng
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
- Shenzhen Research Institute, City University of Hong Kong, Shenzhen, China
| | - Xu-Hong Hu
- Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing, China
| | - Zi-Ning Cui
- National Key Laboratory of Green Pesticide, Integrative Microbiology Research Center, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, China
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Li R, Peng J, Liu Q, Chang Z, Huang Y, Tang J, Lu G. Xanthomonas campestris VemR enhances the transcription of the T3SS key regulator HrpX via physical interaction with HrpG. MOLECULAR PLANT PATHOLOGY 2023; 24:232-247. [PMID: 36626275 PMCID: PMC9923393 DOI: 10.1111/mpp.13293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 11/28/2022] [Accepted: 12/09/2022] [Indexed: 06/17/2023]
Abstract
VemR is a response regulator of the two-component signalling systems (TCSs). It consists solely of a receiver domain. Previous studies have shown that VemR plays an important role in influencing the production of exopolysaccharides and exoenzymes, cell motility, and virulence of Xanthomonas campestris pv. campestris (Xcc). However, whether VemR is involved in the essential pathogenicity determinant type III secretion system (T3SS) is unclear. In this work, we found by transcriptome analysis that VemR modulates about 10% of Xcc genes, which are involved in various cellular processes including the T3SS. Further experiments revealed that VemR physically interacts with numerous proteins, including the TCS sensor kinases HpaS and RavA, and the TCS response regulator HrpG, which directly activates the transcription of HrpX, a key regulator controlling T3SS expression. It has been demonstrated previously that HpaS composes a TCS with HrpG or VemR to control the expression of T3SS or swimming motility, while RavA and VemR form a TCS to control the expression of flagellar genes. Mutation analysis and in vitro transcription assay revealed that phosphorylation might be essential for the function of VemR and phosphorylated VemR could significantly enhance the activation of hrpX transcription by HrpG. We infer that the binding of VemR to HrpG can modulate the activity of HrpG to the hrpX promoter, thereby enhancing hrpX transcription. Although further studies are required to validate this inference and explore the detailed functional mechanism of VemR, our findings provide some insights into the complex regulatory cascade of the HpaS/RavA-VemR/HrpG-HrpX signal transduction system in the control of T3SS.
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Affiliation(s)
- Rui‐Fang Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
- Guangxi Key Laboratory of Biology for Crop Diseases and Insect PestsPlant Protection Research Institute, Guangxi Academy of Agricultural SciencesNanningChina
| | - Jian‐Ling Peng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
| | - Qian‐Qian Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
| | - Zheng Chang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
| | - Yi‐Xin Huang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
| | - Ji‐Liang Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
| | - Guang‐Tao Lu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
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Paauw M, van Hulten M, Chatterjee S, Berg JA, Taks NW, Giesbers M, Richard MMS, van den Burg HA. Hydathode immunity protects the Arabidopsis leaf vasculature against colonization by bacterial pathogens. Curr Biol 2023; 33:697-710.e6. [PMID: 36731466 DOI: 10.1016/j.cub.2023.01.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 10/27/2022] [Accepted: 01/09/2023] [Indexed: 02/04/2023]
Abstract
Plants prevent disease by passively and actively protecting potential entry routes against invading microbes. For example, the plant immune system actively guards roots, wounds, and stomata. How plants prevent vascular disease upon bacterial entry via guttation fluids excreted from specialized glands at the leaf margin remains largely unknown. These so-called hydathodes release xylem sap when root pressure is too high. By studying hydathode colonization by both hydathode-adapted (Xanthomonas campestris pv. campestris) and non-adapted pathogenic bacteria (Pseudomonas syringae pv. tomato) in immunocompromised Arabidopsis mutants, we show that the immune hubs BAK1 and EDS1-PAD4-ADR1 restrict bacterial multiplication in hydathodes. Both immune hubs effectively confine bacterial pathogens to hydathodes and lower the number of successful escape events of an hydathode-adapted pathogen toward the xylem. A second layer of defense, which is dependent on the plant hormones' pipecolic acid and to a lesser extent on salicylic acid, reduces the vascular spread of the pathogen. Thus, besides glands, hydathodes represent a potent first line of defense against leaf-invading microbes.
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Affiliation(s)
- Misha Paauw
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Marieke van Hulten
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Sayantani Chatterjee
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Jeroen A Berg
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Nanne W Taks
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Marcel Giesbers
- Wageningen Electron Microscopy Centre, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 4, 6708 PB Wageningen, The Netherlands
| | - Manon M S Richard
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Harrold A van den Burg
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
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Huang M, Tan X, Song B, Wang Y, Cheng D, Wang B, Chen H. Comparative genomic analysis of Ralstonia solanacearum reveals candidate avirulence effectors in HA4-1 triggering wild potato immunity. FRONTIERS IN PLANT SCIENCE 2023; 14:1075042. [PMID: 36909411 PMCID: PMC9997847 DOI: 10.3389/fpls.2023.1075042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
Ralstonia solanacearum is the causal agent of potato bacterial wilt, a major potato bacterial disease. Among the pathogenicity determinants, the Type III Secretion System Effectors (T3Es) play a vital role in the interaction. Investigating the avirulent T3Es recognized by host resistance proteins is an effective method to uncover the resistance mechanism of potato against R. solanacearum. Two closely related R. solanacearum strains HA4-1 and HZAU091 were found to be avirulent and highly virulent to the wild potato Solanum albicans 28-1, respectively. The complete genome of HZAU091 was sequenced in this study. HZAU091 and HA4-1 shared over 99.9% nucleotide identity with each other. Comparing genomics of closely related strains provides deeper insights into the interaction between hosts and pathogens, especially the mechanism of virulence. The comparison of type III effector repertoires between HA4-1 and HZAU091 uncovered seven distinct effectors. Two predicted effectors RipA5 and the novel effector RipBS in HA4-1 could significantly reduce the virulence of HZAU091 when they were transformed into HZAU091. Furthermore, the pathogenicity assays of mutated strains HA4-1 ΔRipS6, HA4-1 ΔRipO1, HA4-1 ΔRipBS, and HA4-1 ΔHyp6 uncovered that the absence of these T3Es enhanced the HA4-1 virulence to wild potato S. albicans 28-1. This result indicated that these T3Es may be recognized by S. albicans 28-1 as avirulence proteins to trigger the resistance. In summary, this study provides a foundation to unravel the R. solanacearum-potato interaction and facilitates the development of resistance potato against bacterial wilt.
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Affiliation(s)
- Mengshu Huang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Potato Biology and Biotechnology (HZAU), Ministry of Agriculture and Rural Affairs, Wuhan, Hubei, China
- College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Xiaodan Tan
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Potato Biology and Biotechnology (HZAU), Ministry of Agriculture and Rural Affairs, Wuhan, Hubei, China
- College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, Hubei, China
- Guangdong University Key Laboratory for Sustainable Control of Fruit and Vegetable Diseases and Pests & Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China, Ministry of Agriculture and Rural Affairs, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Botao Song
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Potato Biology and Biotechnology (HZAU), Ministry of Agriculture and Rural Affairs, Wuhan, Hubei, China
- College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Yuqi Wang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Potato Biology and Biotechnology (HZAU), Ministry of Agriculture and Rural Affairs, Wuhan, Hubei, China
- College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Dong Cheng
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Potato Biology and Biotechnology (HZAU), Ministry of Agriculture and Rural Affairs, Wuhan, Hubei, China
- College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Bingsen Wang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Potato Biology and Biotechnology (HZAU), Ministry of Agriculture and Rural Affairs, Wuhan, Hubei, China
- College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Huilan Chen
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Potato Biology and Biotechnology (HZAU), Ministry of Agriculture and Rural Affairs, Wuhan, Hubei, China
- College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, Hubei, China
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9
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Breit-McNally C, Laflamme B, Singh RA, Desveaux D, Guttman DS. ZAR1: Guardian of plant kinases. FRONTIERS IN PLANT SCIENCE 2022; 13:981684. [PMID: 36212348 PMCID: PMC9539561 DOI: 10.3389/fpls.2022.981684] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 09/07/2022] [Indexed: 05/25/2023]
Abstract
A key facet of innate immunity in plants entails the recognition of pathogen "effector" virulence proteins by host Nucleotide-Binding Leucine-Rich Repeat Receptors (NLRs). Among characterized NLRs, the broadly conserved ZAR1 NLR is particularly remarkable due to its capacity to recognize at least six distinct families of effectors from at least two bacterial genera. This expanded recognition spectrum is conferred through interactions between ZAR1 and a dynamic network of two families of Receptor-Like Cytoplasmic Kinases (RLCKs): ZED1-Related Kinases (ZRKs) and PBS1-Like Kinases (PBLs). In this review, we survey the history of functional studies on ZAR1, with an emphasis on how the ZAR1-RLCK network functions to trap diverse effectors. We discuss 1) the dynamics of the ZAR1-associated RLCK network; 2) the specificity between ZRKs and PBLs; and 3) the specificity between effectors and the RLCK network. We posit that the shared protein fold of kinases and the switch-like properties of their interactions make them ideal effector sensors, enabling ZAR1 to act as a broad spectrum guardian of host kinases.
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Affiliation(s)
- Clare Breit-McNally
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Bradley Laflamme
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Racquel A. Singh
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Darrell Desveaux
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, ON, Canada
| | - David S. Guttman
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, ON, Canada
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Dubrow ZE, Carpenter SCD, Carter ME, Grinage A, Gris C, Lauber E, Butchachas J, Jacobs JM, Smart CD, Tancos MA, Noël LD, Bogdanove AJ. Cruciferous Weed Isolates of Xanthomonas campestris Yield Insight into Pathovar Genomic Relationships and Genetic Determinants of Host and Tissue Specificity. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2022; 35:791-802. [PMID: 35536128 DOI: 10.1094/mpmi-01-22-0024-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Pathovars of Xanthomonas campestris cause distinct diseases on different brassicaceous hosts. The genomic relationships among pathovars as well as the genetic determinants of host range and tissue specificity remain poorly understood despite decades of research. Here, leveraging advances in multiplexed long-read technology, we fully sequenced the genomes of a collection of X. campestris strains isolated from cruciferous crops and weeds in New York and California as well as strains from global collections, to investigate pathovar relationships and candidate genes for host- and tissue-specificity. Pathogenicity assays and genomic comparisons across this collection and publicly available X. campestris genomes revealed a correlation between pathovar and genomic relatedness and provide support for X. campestris pv. barbareae, the validity of which had been questioned. Linking strain host range with type III effector repertoires identified AvrAC (also 'XopAC') as a candidate host-range determinant, preventing infection of Matthiola incana, and this was confirmed experimentally. Furthermore, the presence of a copy of the cellobiosidase gene cbsA with coding sequence for a signal peptide was found to correlate with the ability to infect vascular tissues, in agreement with a previous study of diverse Xanthomonas species; however, heterologous expression in strains lacking the gene gave mixed results, indicating that factors in addition to cbsA influence tissue specificity of X. campestris pathovars. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.
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Affiliation(s)
- Zoë E Dubrow
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, U.S.A
| | - Sara C D Carpenter
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, U.S.A
| | - Morgan E Carter
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, U.S.A
- School of Plant Sciences, University of Arizona, Tucson, AZ, U.S.A
| | - Ayress Grinage
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, U.S.A
| | - Carine Gris
- LIPME, Université de Toulouse, INRAE, CNRS, Université Paul Sabatier, Castanet-Tolosan, France
| | - Emmanuelle Lauber
- LIPME, Université de Toulouse, INRAE, CNRS, Université Paul Sabatier, Castanet-Tolosan, France
| | - Jules Butchachas
- Department of Plant Pathology, The Ohio State University, Columbus, OH, U.S.A
| | - Jonathan M Jacobs
- Department of Plant Pathology, The Ohio State University, Columbus, OH, U.S.A
| | - Christine D Smart
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, U.S.A
| | - Matthew A Tancos
- Foreign Disease-Weed Science Research Unit, United States Department of Agriculture-Agricultural Research Service, Frederick, MD, U.S.A
| | - Laurent D Noël
- LIPME, Université de Toulouse, INRAE, CNRS, Université Paul Sabatier, Castanet-Tolosan, France
| | - Adam J Bogdanove
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, U.S.A
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11
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Khan A, Wadood SF, Chen M, Wang Y, Xie ZP, Staehelin C. Effector-triggered inhibition of nodulation: A rhizobial effector protease targets soybean kinase GmPBS1-1. PLANT PHYSIOLOGY 2022; 189:2382-2395. [PMID: 35543503 PMCID: PMC9343005 DOI: 10.1093/plphys/kiac205] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 04/01/2022] [Indexed: 05/14/2023]
Abstract
Type III protein secretion systems of nitrogen-fixing rhizobia deliver effector proteins into leguminous host cells to promote or inhibit the nodule symbiosis. However, mechanisms underlying effector-triggered inhibition of nodulation remain largely unknown. Nodulation outer protein T (NopT) of Sinorhizobium sp. NGR234 is an effector protease related to the Pseudomonas effector Avirulence protein Pseudomonas phaseolicola B (AvrPphB). Here, we constructed NGR234 mutants producing different NopT variants and found that protease activity of NopT negatively affects nodulation of smooth crotalaria (Crotalaria pallida). NopT variants lacking residues required for autocleavage and subsequent lipidation showed reduced symbiotic effects and were not targeted to the plasma membrane. We further noticed that Sinorhizobium fredii strains possess a mutated nopT gene. Sinorhizobium fredii USDA257 expressing nopT of NGR234 induced considerably fewer nodules in soybean (Glycine max) cv. Nenfeng 15 but not in other cultivars. Effector perception was further examined in NopT-expressing leaves of Arabidopsis (Arabidopsis thaliana) and found to be dependent on the protein kinase Arabidopsis AvrPphB Susceptible 1 (AtPBS1) and the associated resistance protein Arabidopsis Resistance to Pseudomonas syringae 5 (AtRPS5). Experiments with Nicotiana benthamiana plants indicated that the soybean homolog GmPBS1-1 associated with AtRPS5 can perceive NopT. Further analysis showed that NopT cleaves AtPBS1 and GmPBS1-1 and thus can activate these target proteins. Insertion of a DKM motif at the cleavage site of GmPBS1-1 resulted in increased proteolysis. Nodulation tests with soybeans expressing an autoactive GmPBS1-1 variant indicated that activation of a GmPBS1-1-mediated resistance pathway impairs nodule formation in cv. Nenfeng 15. Our findings suggest that legumes face an evolutionary dilemma of either developing effector-triggered immunity against pathogenic bacteria or establishing symbiosis with suboptimally adapted rhizobia producing pathogen-like effectors.
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Affiliation(s)
- Asaf Khan
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, East Campus, 510006 Guangzhou, China
| | - Syed F Wadood
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, East Campus, 510006 Guangzhou, China
| | - Min Chen
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, East Campus, 510006 Guangzhou, China
| | - Yan Wang
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, East Campus, 510006 Guangzhou, China
| | - Zhi-Ping Xie
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, East Campus, 510006 Guangzhou, China
| | - Christian Staehelin
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, East Campus, 510006 Guangzhou, China
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12
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Ramnarine SDBJ, Jayaraman J, Ramsubhag A. Comparative genomics of the black rot pathogen Xanthomonas campestris pv. campestris and non-pathogenic co-inhabitant Xanthomonas melonis from Trinidad reveal unique pathogenicity determinants and secretion system profiles. PeerJ 2022; 9:e12632. [PMID: 35036136 PMCID: PMC8734464 DOI: 10.7717/peerj.12632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 11/22/2021] [Indexed: 11/20/2022] Open
Abstract
Black-rot disease caused by the phytopathogen Xanthomonas campestris pv. campestris (Xcc) continues to have considerable impacts on the productivity of cruciferous crops in Trinidad and Tobago and the wider Caribbean region. While the widespread occurrence of resistance of Xcc against bactericidal agrochemicals can contribute to the high disease burdens, the role of virulence and pathogenicity features of local strains on disease prevalence and severity has not been investigated yet. In the present study, a comparative genomic analysis was performed on 6 pathogenic Xcc and 4 co-isolated non-pathogenic Xanthomonas melonis (Xmel) strains from diseased crucifer plants grown in fields with heavy chemical use in Trinidad. Native isolates were grouped into two known and four newly assigned ribosomal sequence types (rST). Mobile genetic elements were identified which belonged to the IS3, IS5 family, Tn3 transposon, resolvases, and tra T4SS gene clusters. Additionally, exogenous plasmid derived sequences with origins from other bacterial species were characterised. Although several instances of genomic rearrangements were observed, native Xcc and Xmel isolates shared a significant level of structural homology with reference genomes, Xcc ATCC 33913 and Xmel CFBP4644, respectively. Complete T1SS hlyDB, T2SS, T4SS vir and T5SS xadA, yapH and estA gene clusters were identified in both species. Only Xmel strains contained a complete T6SS but no T3SS. Both species contained a complex repertoire of extracellular cell wall degrading enzymes. Native Xcc strains contained 37 T3SS and effector genes but a variable and unique profile of 8 avr, 4 xop and 1 hpa genes. Interestingly, Xmel strains contained several T3SS effectors with low similarity to references including avrXccA1 (~89%), hrpG (~73%), hrpX (~90%) and xopAZ (~87%). Furthermore, only Xmel genomes contained a CRISPR-Cas I-F array, but no lipopolysaccharide wxc gene cluster. Xmel strains were confirmed to be non-pathogenic by pathogenicity assays. The results of this study will be useful to guide future research into virulence mechanisms, agrochemical resistance, pathogenomics and the potential role of the co-isolated non-pathogenic Xanthomonas strains on Xcc infections.
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Affiliation(s)
- Stephen D B Jr Ramnarine
- Department of Life Sciences, The University of the West Indies, St. Augustine, Trinidad and Tobago
| | - Jayaraj Jayaraman
- Department of Life Sciences, The University of the West Indies, St. Augustine, Trinidad and Tobago
| | - Adesh Ramsubhag
- Department of Life Sciences, The University of the West Indies, St. Augustine, Trinidad and Tobago
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13
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Abstract
Various Gram-negative bacteria use secretion systems to secrete effector proteins that manipulate host biochemical pathways to their benefit. We and others have previously developed machine-learning algorithms to predict novel effectors. Specifically, given a set of known effectors and a set of known non-effectors, the machine-learning algorithm extracts features that distinguish these two protein groups. In the training phase, the machine learning learns how to best combine the features to separate the two groups. The trained machine learning is then applied to open reading frames (ORFs) with unknown functions, resulting in a score for each ORF, which is its likelihood to be an effector. We developed Effectidor, a web server for predicting type III effectors. In this book chapter, we provide a step-by-step introduction to the application of Effectidor, from selecting input data to analyzing the obtained predictions.
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Affiliation(s)
- Naama Wagner
- The Shmunis School of Biomedicine and Cancer Research, Tel Aviv University, Tel Aviv, Israel
| | - Doron Teper
- Department of Plant Pathology and Weed Research, Institute of Plant Protection, Agricultural Research Organization (ARO), Volcani Center, Rishon LeZion, Israel
| | - Tal Pupko
- The Shmunis School of Biomedicine and Cancer Research, Tel Aviv University, Tel Aviv, Israel.
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14
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The Same against Many: AtCML8, a Ca 2+ Sensor Acting as a Positive Regulator of Defense Responses against Several Plant Pathogens. Int J Mol Sci 2021; 22:ijms221910469. [PMID: 34638807 PMCID: PMC8508799 DOI: 10.3390/ijms221910469] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 09/21/2021] [Accepted: 09/24/2021] [Indexed: 01/11/2023] Open
Abstract
Calcium signals are crucial for the activation and coordination of signaling cascades leading to the establishment of plant defense mechanisms. Here, we studied the contribution of CML8, an Arabidopsis calmodulin-like protein in response to Ralstonia solanacearum and to pathogens with different lifestyles, such as Xanthomonas campestris pv. campestris and Phytophtora capsici. We used pathogenic infection assays, gene expression, RNA-seq approaches, and comparative analysis of public data on CML8 knockdown and overexpressing Arabidopsis lines to demonstrate that CML8 contributes to defense mechanisms against pathogenic bacteria and oomycetes. CML8 gene expression is finely regulated at the root level and manipulated during infection with Ralstonia, and CML8 overexpression confers better plant tolerance. To understand the processes controlled by CML8, genes differentially expressed at the root level in the first hours of infection have been identified. Overexpression of CML8 also confers better tolerance against Xanthomonas and Phytophtora, and most of the genes differentially expressed in response to Ralstonia are differentially expressed in these different pathosystems. Collectively, CML8 acts as a positive regulator against Ralstonia solanaceraum and against other vascular or root pathogens, suggesting that CML8 is a multifunctional protein that regulates common downstream processes involved in the defense response of plants to several pathogens.
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15
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Hurtado P, Romero D, López Carrascal CE. ARABIDOPSIS MUESTRA RESISTENCIA NO-HOSPEDERO CONSTITUTIVA CONTRA Xanthomonas phaseoli pv. manihotis. ACTA BIOLÓGICA COLOMBIANA 2021. [DOI: 10.15446/abc.v26n3.83077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
La bacteriosis vascular de la yuca, causada por la bacteria gram negativa Xanthomonas phaseoli pv. manihotis (Xpm), anteriormente conocida como Xanthomonas axonopodis pv. manihotis, es la principal enfermedad bacteriana que compromete su producción. Con la meta de generar una resistencia durable y de amplio espectro a la bacteriosis es posible explotar los mecanismos naturales presentes en plantas no-hospedero. Arabidopsis es una planta modelo extensamente estudiada, la cual es no-hospedero de Xpm. La meta de este estudio fue determinar si la resistencia no-hospedero de Arabidopsis es consecuencia de la presencia de barreras físicas o si esta depende de determinantes genéticos. En este trabajo se evaluó la capacidad de plantas de Arabidopsis de responder a la inoculación con Xpm. Ninguno de los ocho ecotipos de Arabidopsis evaluados mostraron una respuesta hipersensible a la inoculación con ocho diferentes cepas de Xpm. Aunque no se identificó la presencia de especies reactivas de oxígeno si se encontró un bloqueo en el crecimiento de Xpm en las plantas de Arabidopsis. En conjunto, los resultados aquí presentados sugieren que Arabidopsis no está activando una respuesta contra Xpm y que la resistencia observada puede ser consecuencia de las barreras físicas presentes en Arabidopsis que Xpm no es capaz de superar.
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16
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Schreiber KJ, Chau-Ly IJ, Lewis JD. What the Wild Things Do: Mechanisms of Plant Host Manipulation by Bacterial Type III-Secreted Effector Proteins. Microorganisms 2021; 9:1029. [PMID: 34064647 PMCID: PMC8150971 DOI: 10.3390/microorganisms9051029] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/03/2021] [Accepted: 05/04/2021] [Indexed: 01/05/2023] Open
Abstract
Phytopathogenic bacteria possess an arsenal of effector proteins that enable them to subvert host recognition and manipulate the host to promote pathogen fitness. The type III secretion system (T3SS) delivers type III-secreted effector proteins (T3SEs) from bacterial pathogens such as Pseudomonas syringae, Ralstonia solanacearum, and various Xanthomonas species. These T3SEs interact with and modify a range of intracellular host targets to alter their activity and thereby attenuate host immune signaling. Pathogens have evolved T3SEs with diverse biochemical activities, which can be difficult to predict in the absence of structural data. Interestingly, several T3SEs are activated following injection into the host cell. Here, we review T3SEs with documented enzymatic activities, as well as T3SEs that facilitate virulence-promoting processes either indirectly or through non-enzymatic mechanisms. We discuss the mechanisms by which T3SEs are activated in the cell, as well as how T3SEs modify host targets to promote virulence or trigger immunity. These mechanisms may suggest common enzymatic activities and convergent targets that could be manipulated to protect crop plants from infection.
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Affiliation(s)
- Karl J. Schreiber
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94710, USA; (K.J.S.); (I.J.C.-L.)
| | - Ilea J. Chau-Ly
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94710, USA; (K.J.S.); (I.J.C.-L.)
| | - Jennifer D. Lewis
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94710, USA; (K.J.S.); (I.J.C.-L.)
- Plant Gene Expression Center, United States Department of Agriculture, University of California, Berkeley, CA 94710, USA
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17
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Gan YL, Yang LY, Yang LC, Li WL, Liang XL, Jiang W, Jiang GF, Hang XH, Yang M, Tang JL, Jiang BL. The C-terminal domain of the type III secretion chaperone HpaB contributes to dissociation of chaperone-effector complex in Xanthomonas campestris pv. campestris. PLoS One 2021; 16:e0246033. [PMID: 33507993 PMCID: PMC7842900 DOI: 10.1371/journal.pone.0246033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 01/12/2021] [Indexed: 12/01/2022] Open
Abstract
Many animal and plant pathogenic bacteria employ a type three secretion system (T3SS) to deliver type three effector proteins (T3Es) into host cells. Efficient secretion of many T3Es in the plant pathogen Xanthomonas campestris pv. campestris (Xcc) relies on the global chaperone HpaB. However, how the domain of HpaB itself affects effector translocation/secretion is poorly understood. Here, we used genetic and biochemical approaches to identify a novel domain at the C-terminal end of HpaB (amino acid residues 137-160) that contributes to virulence and hypersensitive response (HR). Both in vitro secretion assay and in planta translocation assay showed that the secretion and translocation of T3E proteins depend on the C-terminal region of HpaB. Deletion of the C-terminal region of HpaB did not affect binding to T3Es, self-association or interaction with T3SS components. However, the deletion of C-terminal region sharply reduced the mounts of free T3Es liberated from the complex of HpaB with the T3Es, a reaction catalyzed in an ATP-dependent manner by the T3SS-associated ATPase HrcN. Our findings demonstrate the C-terminal domain of HpaB contributes to disassembly of chaperone-effector complex and reveal a potential molecular mechanism underpinning the involvement of HpaB in secretion of T3Es in Xcc.
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Affiliation(s)
- Yong-Liang Gan
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Li-Yan Yang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Li-Chao Yang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Wan-Lian Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Xue-Lian Liang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Wei Jiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | | | - Xiao-Hong Hang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Mei Yang
- School of Chemistry and Chemical Engineering, Guangxi University, Nanning, China
| | - Ji-Liang Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Bo-Le Jiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
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18
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Huang Y, Li T, Xu T, Tang Z, Guo J, Cai Y. Multiple Xanthomonas campestris pv. campestris 8004 type III effectors inhibit immunity induced by flg22. PLANTA 2020; 252:88. [PMID: 33057902 DOI: 10.1007/s00425-020-03484-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 09/30/2020] [Indexed: 06/11/2023]
Abstract
Xanthomonas campestris pv. campestris 8004 secretes several effector proteins that interfere with plant phosphorylation. Xanthomonas campestris pv. campestris (Xcc) can infect cruciferous plants and cause black rot. The strain Xcc8004 secretes effector proteins that interfere with plant cellular processes into host cells using a type III secretion (T3S) system. Several of the 24 predicted T3S effectors in the Xcc8004 genome have been implicated in the suppression of the Arabidopsis thaliana pattern-triggered immunity (PTI) response. We used an A. thaliana mesophyll protoplast-based assay to identify Xcc8004 T3S effectors that effectively interfere with PTI signalling induced by the bacterial peptide flg22. 11 of the 24 tested effector proteins (XopK, XopQ, HrpW, XopN, XopAC, XopD, XopZ1, XopAG, AvrBs2, XopL and XopX-1) inhibited expression of the flg22-inducible gene FRK1, and five effectors (XopK, XopG, XopQ, XopL and XopX-1) inhibited the expression of the flg22-inducible gene WRKY33. Therefore, there are 12 effector proteins that can inhibit the expression of relevant flg22-inducible genes. It was further investigated whether the 12 effector proteins affect the phosphorylation activation of mitogen-activated protein (MAP) kinases MPK3/MPK6, and four effector proteins (XopK, XopQ, XopZ1 and XopX-1) were found to markedly inhibit MPK3/MPK6 activation. Moreover, a subcellular localisation analysis revealed that the tested effectors were localised within various subcellular compartments. These results indicate that multiple T3S effectors in the Xcc8004 genome interfere with flg22-induced PTI signalling via various molecular mechanisms.
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Affiliation(s)
- Yan Huang
- School of Life Sciences, Sichuan Agricultural University, Ya'an, 625014, China
| | - Tongqi Li
- School of Life Sciences, Sichuan Agricultural University, Ya'an, 625014, China
| | - Ting Xu
- School of Life Sciences, Sichuan Agricultural University, Ya'an, 625014, China
| | - Zizhong Tang
- School of Life Sciences, Sichuan Agricultural University, Ya'an, 625014, China
| | - Jingya Guo
- School of Life Sciences, Sichuan Agricultural University, Ya'an, 625014, China
| | - Yi Cai
- School of Life Sciences, Sichuan Agricultural University, Ya'an, 625014, China.
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19
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An SQ, Potnis N, Dow M, Vorhölter FJ, He YQ, Becker A, Teper D, Li Y, Wang N, Bleris L, Tang JL. Mechanistic insights into host adaptation, virulence and epidemiology of the phytopathogen Xanthomonas. FEMS Microbiol Rev 2020; 44:1-32. [PMID: 31578554 PMCID: PMC8042644 DOI: 10.1093/femsre/fuz024] [Citation(s) in RCA: 117] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 09/29/2019] [Indexed: 01/15/2023] Open
Abstract
Xanthomonas is a well-studied genus of bacterial plant pathogens whose members cause a variety of diseases in economically important crops worldwide. Genomic and functional studies of these phytopathogens have provided significant understanding of microbial-host interactions, bacterial virulence and host adaptation mechanisms including microbial ecology and epidemiology. In addition, several strains of Xanthomonas are important as producers of the extracellular polysaccharide, xanthan, used in the food and pharmaceutical industries. This polymer has also been implicated in several phases of the bacterial disease cycle. In this review, we summarise the current knowledge on the infection strategies and regulatory networks controlling virulence and adaptation mechanisms from Xanthomonas species and discuss the novel opportunities that this body of work has provided for disease control and plant health.
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Affiliation(s)
- Shi-Qi An
- National Biofilms Innovation Centre (NBIC), Biological Sciences, University of Southampton, University Road, Southampton SO17 1BJ, UK
| | - Neha Potnis
- Department of Entomology and Plant Pathology, Rouse Life Science Building, Auburn University, Auburn AL36849, USA
| | - Max Dow
- School of Microbiology, Food Science & Technology Building, University College Cork, Cork T12 K8AF, Ireland
| | | | - Yong-Qiang He
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning 530004, Guangxi, China
| | - Anke Becker
- Loewe Center for Synthetic Microbiology and Department of Biology, Philipps-Universität Marburg, Hans-Meerwein-Straße 6, Marburg 35032, Germany
| | - Doron Teper
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, 700 Experiment Station Road, Lake Alfred 33850, USA
| | - Yi Li
- Bioengineering Department, University of Texas at Dallas, 2851 Rutford Ave, Richardson, TX 75080, USA.,Center for Systems Biology, University of Texas at Dallas, 800 W Campbell Road, Richardson, TX 75080, USA
| | - Nian Wang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, 700 Experiment Station Road, Lake Alfred 33850, USA
| | - Leonidas Bleris
- Bioengineering Department, University of Texas at Dallas, 2851 Rutford Ave, Richardson, TX 75080, USA.,Center for Systems Biology, University of Texas at Dallas, 800 W Campbell Road, Richardson, TX 75080, USA.,Department of Biological Sciences, University of Texas at Dallas, 800 W Campbell Road, Richardson, TX75080, USA
| | - Ji-Liang Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning 530004, Guangxi, China
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20
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Gétaz M, Puławska J, Smits TH, Pothier JF. Host-Pathogen Interactions between Xanthomonas fragariae and Its Host Fragaria × ananassa Investigated with a Dual RNA-Seq Analysis. Microorganisms 2020; 8:E1253. [PMID: 32824783 PMCID: PMC7465820 DOI: 10.3390/microorganisms8081253] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 08/11/2020] [Accepted: 08/14/2020] [Indexed: 12/31/2022] Open
Abstract
Strawberry is economically important and widely grown, but susceptible to a large variety of phytopathogenic organisms. Among them, Xanthomonas fragariae is a quarantine bacterial pathogen threatening strawberry productions by causing angular leaf spots. Using whole transcriptome sequencing, the gene expression of both plant and bacteria in planta was analyzed at two time points, 12 and 29 days post inoculation, in order to compare the pathogen and host response between the stages of early visible and of well-developed symptoms. Among 28,588 known genes in strawberry and 4046 known genes in X. fragariae expressed at both time points, a total of 361 plant and 144 bacterial genes were significantly differentially expressed, respectively. The identified higher expressed genes in the plants were pathogen-associated molecular pattern receptors and pathogenesis-related thaumatin encoding genes, whereas the more expressed early genes were related to chloroplast metabolism as well as photosynthesis related coding genes. Most X. fragariae genes involved in host interaction, recognition, and pathogenesis were lower expressed at late-phase infection. This study gives a first insight into the interaction of X. fragariae with its host. The strawberry plant changed gene expression in order to consistently adapt its metabolism with the progression of infection.
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Affiliation(s)
- Michael Gétaz
- Environmental Genomics and Systems Biology Research Group, Institute of Natural Resource Sciences, Zurich University of Applied Sciences (ZHAW), CH-8820 Wädenswil, Switzerland; (M.G.); (T.H.S.)
| | - Joanna Puławska
- Department of Phytopathology, Research Institute of Horticulture, 96-100 Skierniewice, Poland;
| | - Theo H.M. Smits
- Environmental Genomics and Systems Biology Research Group, Institute of Natural Resource Sciences, Zurich University of Applied Sciences (ZHAW), CH-8820 Wädenswil, Switzerland; (M.G.); (T.H.S.)
| | - Joël F. Pothier
- Environmental Genomics and Systems Biology Research Group, Institute of Natural Resource Sciences, Zurich University of Applied Sciences (ZHAW), CH-8820 Wädenswil, Switzerland; (M.G.); (T.H.S.)
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Wang FF, Qian W. The roles of histidine kinases in sensing host plant and cell-cell communication signal in a phytopathogenic bacterium. Philos Trans R Soc Lond B Biol Sci 2020; 374:20180311. [PMID: 30967026 DOI: 10.1098/rstb.2018.0311] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
It has long been known that phytopathogenic bacteria react to plant-specific stimuli or environmental factors. However, how bacterial cells sense these environmental cues remains incompletely studied. Recently, three kinds of histidine kinases (HKs) were identified as receptors to perceive plant-associated or quorum-sensing signals. Among these kinases, HK VgrS detects iron depletion by binding to ferric iron via an ExxE motif, RpfC binds diffusible signal factor (DSF) by its N-terminal peptide and activates its autokinase activity through relaxation of autoinhibition, and PcrK specifically senses plant hormone-cytokinin and elicits bacterial responses to oxidative stress. These HKs are critical sensors that regulate the virulence of a Gram-negative bacterium, Xanthomonas campestris pv. campestris. Research progress on the signal perception of phytopathogenic bacterial HKs suggests that inter-kingdom signalling between host plants and pathogens controls pathogenesis and can be used as a potential molecular target to protect plants from bacterial diseases. This article is part of the theme issue 'Biotic signalling sheds light on smart pest management'.
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Affiliation(s)
- Fang-Fang Wang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences , Beijing 100101 , People's Republic of China
| | - Wei Qian
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences , Beijing 100101 , People's Republic of China
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Chemical Targeting and Manipulation of Type III Secretion in the Phytopathogen Xanthomonas campestris for Control of Disease. Appl Environ Microbiol 2020; 86:AEM.02349-19. [PMID: 31732574 PMCID: PMC6974632 DOI: 10.1128/aem.02349-19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 11/07/2019] [Indexed: 12/21/2022] Open
Abstract
The bacterium Xanthomonas campestris pv. campestris is known to cause black rot disease in many socioeconomically important vegetable crops worldwide. The management and control of black rot disease have been tackled with chemical and host resistance methods with variable success. This has motivated the development of alternative methods for preventing this disease. Here, we identify a set of novel small molecules capable of inhibiting X. campestris pv. campestris virulence, which may represent leading compounds for the further development of antivirulence agents that could be used in the control of black rot disease. Xanthomonas campestris pv. campestris is the causative agent of black rot disease in crucifer plants. This Gram-negative bacterium utilizes the type III secretion system (T3SS), encoded by the hrp gene cluster, to aid in its resistance to host defenses and the ability to cause disease. The T3SS injects a set of proteins known as effectors into host cells that come into contact with the bacterium. The T3SS is essential for the virulence and hypersensitive response (HR) of X. campestris pv. campestris, making it a potential target for disease control strategies. Using a unique and straightforward high-throughput screening method, we examined a large collection of diverse small molecules for their potential to modulate the T3SS without affecting the growth of X. campestris pv. campestris. Screening of 13,129 different compounds identified 10 small molecules that had a significant inhibitory influence on T3SS. Moreover, reverse transcription-quantitative PCR (qRT-PCR) assays demonstrated that all 10 compounds repress the expression of the hrp genes. Interestingly, the effect of these small molecules on hrp genes may be through the HpaS and ColS sensor kinase proteins that are key to the regulation of the T3SS in planta. Five of the compounds were also capable of inhibiting X. campestris pv. campestris virulence in a Chinese radish leaf-clipping assay. Furthermore, seven of the small molecules significantly weakened the HR in nonhost pepper plants challenged with X. campestris pv. campestris. Taken together, these small molecules may provide potential tool compounds for the further development of antivirulence agents that could be used in disease control of the plant pathogen X. campestris pv. campestris. IMPORTANCE The bacterium Xanthomonas campestris pv. campestris is known to cause black rot disease in many socioeconomically important vegetable crops worldwide. The management and control of black rot disease have been tackled with chemical and host resistance methods with variable success. This has motivated the development of alternative methods for preventing this disease. Here, we identify a set of novel small molecules capable of inhibiting X. campestris pv. campestris virulence, which may represent leading compounds for the further development of antivirulence agents that could be used in the control of black rot disease.
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Tan X, Qiu H, Li F, Cheng D, Zheng X, Wang B, Huang M, Li W, Li Y, Sang K, Song B, Du J, Chen H, Xie C. Complete Genome Sequence of Sequevar 14M Ralstonia solanacearum Strain HA4-1 Reveals Novel Type III Effectors Acquired Through Horizontal Gene Transfer. Front Microbiol 2019; 10:1893. [PMID: 31474968 PMCID: PMC6703095 DOI: 10.3389/fmicb.2019.01893] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 07/31/2019] [Indexed: 01/08/2023] Open
Abstract
Ralstonia solanacearum, which causes bacterial wilt in a broad range of plants, is considered a "species complex" due to its significant genetic diversity. Recently, we have isolated a new R. solanacearum strain HA4-1 from Hong'an county in Hubei province of China and identified it being phylotype I, sequevar 14M (phylotype I-14M). Interestingly, we found that it can cause various disease symptoms among different potato genotypes and display different pathogenic behavior compared to a phylogenetically related strain, GMI1000. To dissect the pathogenic mechanisms of HA4-1, we sequenced its whole genome by combined sequencing technologies including Illumina HiSeq2000, PacBio RS II, and BAC-end sequencing. Genome assembly results revealed the presence of a conventional chromosome, a megaplasmid as well as a 143 kb plasmid in HA4-1. Comparative genome analysis between HA4-1 and GMI1000 shows high conservation of the general virulence factors such as secretion systems, motility, exopolysaccharides (EPS), and key regulatory factors, but significant variation in the repertoire and structure of type III effectors, which could be the determinants of their differential pathogenesis in certain potato species or genotypes. We have identified two novel type III effectors that were probably acquired through horizontal gene transfer (HGT). These novel R. solanacearum effectors display homology to several YopJ and XopAC family members. We named them as RipBR and RipBS. Notably, the copy of RipBR on the plasmid is a pseudogene, while the other on the megaplasmid is normal. For RipBS, there are three copies located in the megaplasmid and plasmid, respectively. Our results have not only enriched the genome information on R. solanacearum species complex by sequencing the first sequevar 14M strain and the largest plasmid reported in R. solanacearum to date but also revealed the variation in the repertoire of type III effectors. This will greatly contribute to the future studies on the pathogenic evolution, host adaptation, and interaction between R. solanacearum and potato.
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Affiliation(s)
- Xiaodan Tan
- Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
- National Center for Vegetable Improvement (Central China), Wuhan, China
| | - Huishan Qiu
- Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
- National Center for Vegetable Improvement (Central China), Wuhan, China
| | - Feng Li
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
- National Center for Vegetable Improvement (Central China), Wuhan, China
| | - Dong Cheng
- Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
- National Center for Vegetable Improvement (Central China), Wuhan, China
| | - Xueao Zheng
- Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
- National Center for Vegetable Improvement (Central China), Wuhan, China
| | - Bingsen Wang
- Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
- National Center for Vegetable Improvement (Central China), Wuhan, China
| | - Mengshu Huang
- Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
- National Center for Vegetable Improvement (Central China), Wuhan, China
| | - Wenhao Li
- Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
- National Center for Vegetable Improvement (Central China), Wuhan, China
| | - Yanping Li
- Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
- National Center for Vegetable Improvement (Central China), Wuhan, China
| | - Kangqi Sang
- Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, China
| | - Botao Song
- Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
- National Center for Vegetable Improvement (Central China), Wuhan, China
| | - Juan Du
- Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
- National Center for Vegetable Improvement (Central China), Wuhan, China
| | - Huilan Chen
- Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
- National Center for Vegetable Improvement (Central China), Wuhan, China
| | - Conghua Xie
- Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, China
- National Center for Vegetable Improvement (Central China), Wuhan, China
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A type III effector XopL8004 is vital for Xanthomonas campestris pathovar campestris to regulate plant immunity. Res Microbiol 2019; 170:138-146. [DOI: 10.1016/j.resmic.2018.12.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 11/05/2018] [Accepted: 12/04/2018] [Indexed: 11/21/2022]
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Armitage AD, Lysøe E, Nellist CF, Lewis LA, Cano LM, Harrison RJ, Brurberg MB. Bioinformatic characterisation of the effector repertoire of the strawberry pathogen Phytophthora cactorum. PLoS One 2018; 13:e0202305. [PMID: 30278048 PMCID: PMC6168125 DOI: 10.1371/journal.pone.0202305] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Accepted: 06/23/2018] [Indexed: 12/21/2022] Open
Abstract
The oomycete pathogen Phytophthora cactorum causes crown rot, a major disease of cultivated strawberry. We report the draft genome of P. cactorum isolate 10300, isolated from symptomatic Fragaria x ananassa tissue. Our analysis revealed that there are a large number of genes encoding putative secreted effectors in the genome, including nearly 200 RxLR domain containing effectors, 77 Crinklers (CRN) grouped into 38 families, and numerous apoplastic effectors, such as phytotoxins (PcF proteins) and necrosis inducing proteins. As in other Phytophthora species, the genomic environment of many RxLR and CRN genes differed from core eukaryotic genes, a hallmark of the two-speed genome. We found genes homologous to known Phytophthora infestans avirulence genes including Avr1, Avr3b, Avr4, Avrblb1 and AvrSmira2 indicating effector sequence conservation between Phytophthora species of clade 1a and clade 1c. The reported P. cactorum genome sequence and associated annotations represent a comprehensive resource for avirulence gene discovery in other Phytophthora species from clade 1 and, will facilitate effector informed breeding strategies in other crops.
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Affiliation(s)
| | - Erik Lysøe
- Norwegian Institute of Bioeconomy Research (NIBIO), Division of Biotechnology and Plant Health, Ås, Norway
| | | | | | - Liliana M. Cano
- University of Florida, UF/IFAS Indian River Research and Education Center, Fort Pierce, Florida, United States of America
- The Sainsbury Laboratory, Norwich, United Kingdom
| | | | - May B. Brurberg
- Norwegian Institute of Bioeconomy Research (NIBIO), Division of Biotechnology and Plant Health, Ås, Norway
- Norwegian University of Life Sciences (NMBU), Department of Plant Sciences, Ås, Norway
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26
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Jiang BL, Jiang GF, Liu W, Yang LC, Yang LY, Wang L, Hang XH, Tang JL. RpfC regulates the expression of the key regulator hrpX of the hrp/T3SS system in Xanthomonas campestris pv. campestris. BMC Microbiol 2018; 18:103. [PMID: 30176800 PMCID: PMC6122198 DOI: 10.1186/s12866-018-1233-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 08/15/2018] [Indexed: 12/02/2022] Open
Abstract
Background The Gram-negative phytopathogenic bacterium Xanthomonas campestris pv. campestris recruits the hrp/T3SS system to inject pathogenicity effector proteins into host cells and uses the rpf/DSF cell-cell signaling system to regulate the expression of virulence factors such as extracellular enzymes and polysaccharide. Whether these two systems have any connection is unknown. Methods Positive regulator candidates affecting hrpX expression were identified by sacB strategy. The transcriptional expression was determined by qRT-PCR and GUS activity analysis. Transcriptome analysis was performed by RNA deep-sequencing. The hypersensitive response (HR) was determined in the nonhost plant pepper ECW-10R and electrolyte leakage assay. Results Mutation of the gene encoding the sensor RpfC of the rpf/DSF system significantly reduced the expression of hrpX, the key regulator of the hrp/T3SS system, all of the genes in the hrp cluster and most reported type III effector genes. Mutation of rpfG did not affect the expression of hrpX. The rpfC mutant showed a delayed and weakened HR induction. Conclusions RpfC positively regulates the expression of hrpX independent of RpfG, showing a complex regulatory network linking the rpf/DSF and hrp/T3SS systems. Electronic supplementary material The online version of this article (10.1186/s12866-018-1233-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Bo-Le Jiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004, Guangxi, China
| | - Guo-Feng Jiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004, Guangxi, China
| | - Wei Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004, Guangxi, China
| | - Li-Chao Yang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004, Guangxi, China
| | - Li-Yan Yang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004, Guangxi, China
| | - Lin Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004, Guangxi, China
| | - Xiao-Hong Hang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004, Guangxi, China
| | - Ji-Liang Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004, Guangxi, China.
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Yang LY, Yang LC, Gan YL, Wang L, Zhao WZ, He YQ, Jiang W, Jiang BL, Tang JL. Systematic Functional Analysis of Sigma (σ) Factors in the Phytopathogen Xanthomonas campestris Reveals Novel Roles in the Regulation of Virulence and Viability. Front Microbiol 2018; 9:1749. [PMID: 30123197 PMCID: PMC6085468 DOI: 10.3389/fmicb.2018.01749] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 07/12/2018] [Indexed: 11/13/2022] Open
Abstract
The black rot pathogen Xanthomonas campestris pv. campestris (Xcc) is a model organism for the study of plant bacterial pathogenesis mechanisms. In bacteria, σ factors serve as important regulatory elements that respond to various environmental signals and cues. Though Xcc encodes 15 putative σ factors little is known about their roles. As an approach to identify the potential role of each σ factor, we constructed mutations in each of the σ-factor genes as well as generating mutants deficient in multiple σ factors to assess these regulators potential additive functions. The work identified two σ70 factors essential for growth. Furthermore, the work discovered a third σ70 factor, RpoE1, important for virulence. Further studies revealed that RpoE1 positively regulates the expression of the hrp gene cluster that encodes the type III secretion system (T3SS) which determines the pathogenicity and hypersensitive response of Xcc on plants. In vivo and in vitro studies demonstrated that RpoE1 could bind to the promoter region and promote transcription of hrpX, a gene encoding a key regulator of the hrp genes. Overall, this systematic analysis reveals important roles in Xcc survival and virulence for previously uncharacterized σ70 factors that may become important targets for disease control.
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Affiliation(s)
- Li-Yan Yang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Li-Chao Yang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Yong-Liang Gan
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Lin Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Wan-Zong Zhao
- Guangxi Key Laboratory of Power System Optimization and Energy Technology, Guangxi University, Nanning, China
| | - Yong-Qiang He
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Wei Jiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Bo-Le Jiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Ji-Liang Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
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Denancé N, Szurek B, Doyle EL, Lauber E, Fontaine-Bodin L, Carrère S, Guy E, Hajri A, Cerutti A, Boureau T, Poussier S, Arlat M, Bogdanove AJ, Noël LD. Two ancestral genes shaped the Xanthomonas campestris TAL effector gene repertoire. THE NEW PHYTOLOGIST 2018; 219:391-407. [PMID: 29677397 DOI: 10.1111/nph.15148] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 03/06/2018] [Indexed: 06/08/2023]
Abstract
Xanthomonas transcription activator-like effectors (TALEs) are injected inside plant cells to promote host susceptibility by enhancing transcription of host susceptibility genes. TALE-encoding (tal) genes were thought to be absent from Brassicaceae-infecting Xanthomonas campestris (Xc) genomes based on four reference genomic sequences. We discovered tal genes in 26 of 49 Xc strains isolated worldwide and used a combination of single molecule real time (SMRT) and tal amplicon sequencing to yield a near-complete description of the TALEs found in Xc (Xc TALome). The 53 sequenced tal genes encode 21 distinct DNA binding domains that sort into seven major DNA binding specificities. In silico analysis of the Brassica rapa promoterome identified a repertoire of predicted TALE targets, five of which were experimentally validated using quantitative reverse transcription polymerase chain reaction. The Xc TALome shows multiple signs of DNA rearrangements that probably drove its evolution from two ancestral tal genes. We discovered that Tal12a and Tal15a of Xcc strain Xca5 contribute together in the development of disease symptoms on susceptible B. oleracea var. botrytis cv Clovis. This large and polymorphic repertoire of TALEs opens novel perspectives for elucidating TALE-mediated susceptibility of Brassicaceae to black rot disease and for understanding the molecular processes underlying TALE evolution.
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Affiliation(s)
- Nicolas Denancé
- LIPM, Université de Toulouse, INRA, CNRS, UPS, F-31326, Castanet-Tolosan Cedex, France
| | - Boris Szurek
- IRD, Cirad, Univ. Montpellier, IPME, Montpellier, France
| | - Erin L Doyle
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, 50011, USA
- Department of Biology, Doane University, Crete, NE, 68333, USA
| | - Emmanuelle Lauber
- LIPM, Université de Toulouse, INRA, CNRS, UPS, F-31326, Castanet-Tolosan Cedex, France
| | | | - Sébastien Carrère
- LIPM, Université de Toulouse, INRA, CNRS, UPS, F-31326, Castanet-Tolosan Cedex, France
| | - Endrick Guy
- LIPM, Université de Toulouse, INRA, CNRS, UPS, F-31326, Castanet-Tolosan Cedex, France
| | - Ahmed Hajri
- IRHS, INRA, AGROCAMPUS-Ouest, Université d'Angers, SFR 4207 QUASAV, 49071, Beaucouzé Cedex, France
| | - Aude Cerutti
- LIPM, Université de Toulouse, INRA, CNRS, UPS, F-31326, Castanet-Tolosan Cedex, France
| | - Tristan Boureau
- IRHS, INRA, AGROCAMPUS-Ouest, Université d'Angers, SFR 4207 QUASAV, 49071, Beaucouzé Cedex, France
| | - Stéphane Poussier
- IRHS, INRA, AGROCAMPUS-Ouest, Université d'Angers, SFR 4207 QUASAV, 49071, Beaucouzé Cedex, France
| | - Matthieu Arlat
- LIPM, Université de Toulouse, INRA, CNRS, UPS, F-31326, Castanet-Tolosan Cedex, France
| | - Adam J Bogdanove
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, 50011, USA
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
| | - Laurent D Noël
- LIPM, Université de Toulouse, INRA, CNRS, UPS, F-31326, Castanet-Tolosan Cedex, France
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Wang FX, Luo YM, Ye ZQ, Cao X, Liang JN, Wang Q, Wu Y, Wu JH, Wang HY, Zhang M, Cheng HQ, Xia GX. iTRAQ-based proteomics analysis of autophagy-mediated immune responses against the vascular fungal pathogen Verticillium dahliae in Arabidopsis. Autophagy 2018; 14:598-618. [PMID: 29369001 PMCID: PMC5959329 DOI: 10.1080/15548627.2017.1423438] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 12/19/2017] [Accepted: 12/28/2017] [Indexed: 01/09/2023] Open
Abstract
The mechanisms underlying the functional link between autophagy and plant innate immunity remain largely unknown. In this study, we investigated the autophagy-mediated plant defense responses against Verticillium dahliae (V. dahliae) infection by comparative proteomics and cellular analyses. An assessment of the autophagy activity and disease development showed that autophagic processes were tightly related to the tolerance of Arabidopsis plant to Verticillium wilt. An isobaric tags for relative and absolute quantification (iTRAQ)-based proteomics analysis was performed, and we identified a total of 780 differentially accumulated proteins (DAPs) between wild-type and mutant atg10-1 Arabidopsis plants upon V. dahliae infection, of which, 193 ATG8-family-interacting proteins were identified in silico and their associations with autophagy were verified for several selected proteins. Three important aspects of autophagy-mediated defense against V. dahliae infection were revealed: 1) autophagy is required for the activation of upstream defense responses; 2) autophagy-mediated mitochondrial degradation (mitophagy) occurs and is an important player in the defense process; and 3) autophagy promotes the transdifferentiation of perivascular cells and the formation of xylem hyperplasia, which are crucial for protection against this vascular disease. Together, our results provide several novel insights for understanding the functional association between autophagy and plant immune responses.
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Affiliation(s)
- Fu-Xin Wang
- Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Plant Genomics and National Center, Beijing, China
| | - Yuan-Ming Luo
- Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Microbial Resources, Beijing, China
| | - Zi-Qin Ye
- College of Life Sciences, Capital Normal University, Beijing, China
| | - Xue Cao
- College of Life Sciences, Capital Normal University, Beijing, China
| | - Jing-Nan Liang
- Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Qian Wang
- Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Yao Wu
- Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Plant Genomics and National Center, Beijing, China
| | - Jia-He Wu
- Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Plant Genomics and National Center, Beijing, China
| | - Hai-Yun Wang
- Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Plant Genomics and National Center, Beijing, China
| | - Min Zhang
- Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Plant Genomics and National Center, Beijing, China
| | - Huan-Qing Cheng
- Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Plant Genomics and National Center, Beijing, China
| | - Gui-Xian Xia
- Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Plant Genomics and National Center, Beijing, China
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Kourelis J, van der Hoorn RAL. Defended to the Nines: 25 Years of Resistance Gene Cloning Identifies Nine Mechanisms for R Protein Function. THE PLANT CELL 2018; 30:285-299. [PMID: 29382771 PMCID: PMC5868693 DOI: 10.1105/tpc.17.00579] [Citation(s) in RCA: 433] [Impact Index Per Article: 72.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 12/14/2017] [Accepted: 01/29/2018] [Indexed: 05/18/2023]
Abstract
Plants have many, highly variable resistance (R) gene loci, which provide resistance to a variety of pathogens. The first R gene to be cloned, maize (Zea mays) Hm1, was published over 25 years ago, and since then, many different R genes have been identified and isolated. The encoded proteins have provided clues to the diverse molecular mechanisms underlying immunity. Here, we present a meta-analysis of 314 cloned R genes. The majority of R genes encode cell surface or intracellular receptors, and we distinguish nine molecular mechanisms by which R proteins can elevate or trigger disease resistance: direct (1) or indirect (2) perception of pathogen-derived molecules on the cell surface by receptor-like proteins and receptor-like kinases; direct (3) or indirect (4) intracellular detection of pathogen-derived molecules by nucleotide binding, leucine-rich repeat receptors, or detection through integrated domains (5); perception of transcription activator-like effectors through activation of executor genes (6); and active (7), passive (8), or host reprogramming-mediated (9) loss of susceptibility. Although the molecular mechanisms underlying the functions of R genes are only understood for a small proportion of known R genes, a clearer understanding of mechanisms is emerging and will be crucial for rational engineering and deployment of novel R genes.
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Affiliation(s)
- Jiorgos Kourelis
- The Plant Chemetics Laboratory, Department of Plant Sciences, University of Oxford, OX1 3RB Oxford, United Kingdom
| | - Renier A L van der Hoorn
- The Plant Chemetics Laboratory, Department of Plant Sciences, University of Oxford, OX1 3RB Oxford, United Kingdom
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31
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Levy A, Salas Gonzalez I, Mittelviefhaus M, Clingenpeel S, Herrera Paredes S, Miao J, Wang K, Devescovi G, Stillman K, Monteiro F, Rangel Alvarez B, Lundberg DS, Lu TY, Lebeis S, Jin Z, McDonald M, Klein AP, Feltcher ME, Rio TG, Grant SR, Doty SL, Ley RE, Zhao B, Venturi V, Pelletier DA, Vorholt JA, Tringe SG, Woyke T, Dangl JL. Genomic features of bacterial adaptation to plants. Nat Genet 2017; 50:138-150. [PMID: 29255260 PMCID: PMC5957079 DOI: 10.1038/s41588-017-0012-9] [Citation(s) in RCA: 296] [Impact Index Per Article: 42.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 11/10/2017] [Indexed: 01/10/2023]
Abstract
Plants intimately associate with diverse bacteria. Plant-associated (PA) bacteria have ostensibly evolved genes enabling adaptation to the plant environment. However, the identities of such genes are mostly unknown and their functions are poorly characterized. We sequenced 484 genomes of bacterial isolates from roots of Brassicaceae, poplar, and maize. We then compared 3837 bacterial genomes to identify thousands of PA gene clusters. Genomes of PA bacteria encode more carbohydrate metabolism functions and fewer mobile elements than related non-plant associated genomes. We experimentally validated candidates from two sets of PA genes, one involved in plant colonization, the other serving in microbe-microbe competition between PA bacteria. We also identified 64 PA protein domains that potentially mimic plant domains; some are shared with PA fungi and oomycetes. This work expands the genome-based understanding of plant-microbe interactions and provides leads for efficient and sustainable agriculture through microbiome engineering.
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Affiliation(s)
- Asaf Levy
- DOE Joint Genome Institute, Walnut Creek, CA, USA
| | - Isai Salas Gonzalez
- Department of Biology, University of North Carolina, Chapel Hill, NC, USA.,Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | | | | | - Sur Herrera Paredes
- Department of Biology, University of North Carolina, Chapel Hill, NC, USA.,Howard Hughes Medical Institute, Chevy Chase, MD, USA.,Department of Biology, Stanford University, Stanford, CA, USA
| | - Jiamin Miao
- Department of Horticulture, Virginia Tech, Blacksburg, VA, USA.,The Grassland College, Gansu Agricultural University, Lanzhou, Gansu, China
| | - Kunru Wang
- Department of Horticulture, Virginia Tech, Blacksburg, VA, USA
| | - Giulia Devescovi
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | | | - Freddy Monteiro
- Department of Biology, University of North Carolina, Chapel Hill, NC, USA.,Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | | | - Derek S Lundberg
- Department of Biology, University of North Carolina, Chapel Hill, NC, USA.,Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Tse-Yuan Lu
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Sarah Lebeis
- Department of Microbiology, University of Tennessee, Knoxville, TN, USA
| | - Zhao Jin
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Meredith McDonald
- Department of Biology, University of North Carolina, Chapel Hill, NC, USA.,Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Andrew P Klein
- Department of Biology, University of North Carolina, Chapel Hill, NC, USA.,Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Meghan E Feltcher
- Department of Biology, University of North Carolina, Chapel Hill, NC, USA.,Howard Hughes Medical Institute, Chevy Chase, MD, USA.,BD Technologies and Innovation, Research Triangle Park, NC, USA
| | | | - Sarah R Grant
- Department of Biology, University of North Carolina, Chapel Hill, NC, USA
| | - Sharon L Doty
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA, USA
| | - Ruth E Ley
- Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Bingyu Zhao
- Department of Horticulture, Virginia Tech, Blacksburg, VA, USA
| | - Vittorio Venturi
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Dale A Pelletier
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | | | - Susannah G Tringe
- DOE Joint Genome Institute, Walnut Creek, CA, USA. .,School of Natural Sciences, University of California, Merced, Merced, CA, USA.
| | - Tanja Woyke
- DOE Joint Genome Institute, Walnut Creek, CA, USA. .,School of Natural Sciences, University of California, Merced, Merced, CA, USA.
| | - Jeffery L Dangl
- Department of Biology, University of North Carolina, Chapel Hill, NC, USA. .,Howard Hughes Medical Institute, Chevy Chase, MD, USA. .,The Carolina Center for Genome Sciences, University of North Carolina, Chapel Hill, NC, USA. .,Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC, USA.
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32
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Islam MT, Lee BR, Park SH, La VH, Bae DW, Kim TH. Cultivar Variation in Hormonal Balance Is a Significant Determinant of Disease Susceptibility to Xanthomonas campestris pv. campestris in Brassica napus. FRONTIERS IN PLANT SCIENCE 2017; 8:2121. [PMID: 29312385 PMCID: PMC5732936 DOI: 10.3389/fpls.2017.02121] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 11/29/2017] [Indexed: 05/09/2023]
Abstract
This study aimed to directly elucidate cultivar variation in disease susceptibility and disease responses in relation to hormonal status in the interaction of Brassica napus cultivars and Xanthomonas campestris pv. campestris (Xcc), the causal agent of black rot disease. Fully expanded leaves of six B. napus cultivars (cvs. Capitol, Youngsan, Saturnin, Colosse, Tamra, and Mosa) were inoculated with Xcc. At 14 days post-inoculation with Xcc, cultivar variation in susceptibility or resistance was interpreted with defense responses as estimated by redox status, defensive metabolites, and expression of phenylpropanoid synthesis-related genes in relation to endogenous hormonal status. Disease susceptibility of six cultivars was distinguished by necrotic lesions in the Xcc-inoculated leaves and characterized concurrently based on the higher increase in reactive oxygen species and lipid peroxidation. Among these cultivars, as the susceptibility was higher, the ratios of abscisic acid (ABA)/jasmonic acid (JA) and salicylic acid (SA)/JA tended to increase with enhanced expression of SA signaling regulatory gene NPR1 and transcriptional factor TGA1 and antagonistic suppression of JA-regulated gene PDF 1.2. In the resistant cultivar (cv. Capitol), accumulation of defensive metabolites with enhanced expression of genes involved in flavonoids (chalcone synthase), proanthocyanidins (anthocyanidin reductase), and hydroxycinnamic acids (ferulate-5-hydroxylase) biosynthesis and higher redox status were observed, whereas the opposite results were obtained for susceptible cultivars (cvs. Mosa and Tamra). These results clearly indicate that cultivar variation in susceptibility to infection by Xcc was determined by enhanced alteration of the SA/JA ratio, as a negative regulator of redox status and phenylpropanoid synthesis in the Brasica napus-Xcc pathosystem.
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Affiliation(s)
- Md. Tabibul Islam
- Department of Animal Science, Institute of Agricultural Science and Technology, College of Agriculture and Life Science, Chonnam National University, Gwangju, South Korea
| | - Bok-Rye Lee
- Department of Animal Science, Institute of Agricultural Science and Technology, College of Agriculture and Life Science, Chonnam National University, Gwangju, South Korea
- Biotechnology Research Institute, Chonnam National University, Gwangju, South Korea
| | - Sang-Hyun Park
- Department of Animal Science, Institute of Agricultural Science and Technology, College of Agriculture and Life Science, Chonnam National University, Gwangju, South Korea
| | - Van Hien La
- Department of Animal Science, Institute of Agricultural Science and Technology, College of Agriculture and Life Science, Chonnam National University, Gwangju, South Korea
| | - Dong-Won Bae
- Central Instrument Facility, Gyeongsang National University, Jinju, South Korea
| | - Tae-Hwan Kim
- Department of Animal Science, Institute of Agricultural Science and Technology, College of Agriculture and Life Science, Chonnam National University, Gwangju, South Korea
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33
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Maximiano MR, Oliveira-Neto OB, Franco OL, Mehta A. Validation of an in vitro system for studies of pathogenicity mechanisms in Xanthomonas campestris. FEMS Microbiol Lett 2017; 364:4494362. [PMID: 29040467 DOI: 10.1093/femsle/fnx217] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 10/11/2017] [Indexed: 01/16/2023] Open
Abstract
Several minimal media capable of inducing pathogenicity genes have been used to study plant-pathogen interactions. An in planta assay to study a closer interaction between the bacteria and the host was also developed and has been employed by our group. In order to determine whether growth medium could be improved to better approximate in planta conditions beyond that offered by the defined minimal medium XVM1, we compared the expression of 20 Xanthomonas campestris pv. campestris (Xcc) genes by quantitative reverse transcription - polymerase chain reaction (qRT-PCR) under in vivo (bacteria recovered from the plant) and in vitro (rich medium NYG, minimal medium XVM1 and XVM1 + leaf extract) growth systems. The results showed a higher expression level of the genes in the in planta system when compared to growth in culture media. In planta growth is closest to a real interaction condition and captures the complexity of the plant cell environment; however, this system has some limitations. The main finding of our work is that the addition of plant extract to XVM1 medium results in a gene expression profile that better matches the in planta profile, when compared with the XVM1 medium alone, giving support to the use of plant extract to study pathogenicity mechanisms in Xanthomonas.
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Affiliation(s)
- Mariana Rocha Maximiano
- Embrapa Recursos Genéticos e Biotecnologia, PBI, Av. W/5 Norte Final, Brasília, Distrito Federal 70770-917, Brazil.,Programa de Pós-Graduação em Ciências Biológicas (Imunologia e DIP/Genética e Biotecnologia), Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer, S/n - Martelos, Juiz de Fora, Minas Gerais, 36036-330, Brazil
| | - Osmundo B Oliveira-Neto
- Embrapa Recursos Genéticos e Biotecnologia, PBI, Av. W/5 Norte Final, Brasília, Distrito Federal 70770-917, Brazil
| | - Octávio L Franco
- Programa de Pós-Graduação em Ciências Biológicas (Imunologia e DIP/Genética e Biotecnologia), Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer, S/n - Martelos, Juiz de Fora, Minas Gerais, 36036-330, Brazil.,S-Inova Biotech, Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Av. Tamandaré, 6000, Campo Grande, Mato Grosso do Sul, 79117-900, Brazil.,Centro de Analises Proteômicas e Bioquímicas, Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, SGAN 916N, Modulo C, Sala 219, Brasília, Distrito Federal 70790-100, Brazil
| | - Angela Mehta
- Embrapa Recursos Genéticos e Biotecnologia, PBI, Av. W/5 Norte Final, Brasília, Distrito Federal 70770-917, Brazil
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34
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Díaz-Tatis PA, Trujillo-Beltrán CA, Bernal-Giraldo AJ, López-Carrascal CE. HPAF de <i>Xanthomonas axonopodis</i> PV. <i>manihotis</i> regula negativamente genes relacionados con metabolismo y defensa en hojas de yuca. ACTUALIDADES BIOLÓGICAS 2017. [DOI: 10.17533/udea.acbi.329002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
Las bacterias fitopatógenas de los géneros Erwinia, Pantoea, Pseudomonas, Ralstonia y Xanthomonas causan una gran cantidad de enfermedades en diversos cultivos. La base molecular que explica parcialmente la patogenicidad de estas bacterias radica en la translocación de proteínas efectoras hacia el interior de las células hospederas a través del sistema de secreción tipo tres (SST3). Xanthomonas axonopodis pv. manihotis (Xam) es un bacilo gram negativo y es el agente causal de la bacteriosis vascular de la yuca (Manihot esculenta Crantz). Los estudios derivados de la secuenciación del genoma de diversas cepas de Xam han permitido la identificación de hrp-associated F (HpaF) como un efector principal presente en todas las cepas secuenciadas de Latinoamérica, África y Asia. En este trabajo se evaluó la importancia de HpaF en la virulencia de Xam empleando dos estrategias. Primeramente, se pudo determinar a nivel histológico cambios morfológicos en las células de yuca causadas por HpaF. En segundo lugar, se empleó una estrategia de transcriptómica comparativa empleando un microarreglo de ADNc de yuca y ARN obtenido de plantas de yuca inoculadas con cepas de Xam mutadas en hpaF (ΔhpaF) o complementadas (ΔhpaF +hpaF). Los datos obtenidos sugieren que HpaF es un factor de virulencia de Xam ya que regula negativamente genes involucrados en el metabolismo y defensa de la planta.
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35
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Sherif SM, Erland LA, Shukla MR, Saxena PK. Bark and wood tissues of American elm exhibit distinct responses to Dutch elm disease. Sci Rep 2017; 7:7114. [PMID: 28769110 PMCID: PMC5540924 DOI: 10.1038/s41598-017-07779-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 07/04/2017] [Indexed: 01/08/2023] Open
Abstract
Tolerance to Dutch elm disease (DED) has been linked to the rapid and/or high induction of disease-responsive genes after infection with the fungus Ophiostoma novo-ulmi. Although the fungal infection by O. novo-ulmi primarily takes places in xylem vessels, it is still unclear how xylem contributes to the defense against DED. Taking advantage of the easy separation of wood and bark tissues in young American elm saplings, here we show that most disease-responsive genes exhibited higher expression in wood compared to bark tissues after fungal infection. On the other hand, the stress-related phytohormones were generally more abundant in the bark compared to wood tissues. However, only endogenous levels of jasmonates (JAs), but not salicylic acid (SA) and abscisic acid (ABA) increased in the inoculated tissues. This, along with the upregulation of JA-biosynthesis genes in inoculated bark and core tissues further suggest that phloem and xylem might contribute to the de novo biosynthesis of JA after fungal infection. The comparison between two tolerant elm varieties, 'Valley Forge' and 'Princeton,' also indicated that tolerance against DED might be mediated by different mechanisms in the xylem. The present study sheds some light on the amplitude and kinetics of defense responses produced in the xylem and phloem in response to DED.
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Affiliation(s)
- S M Sherif
- Gosling Research Institute for Plant Preservation, Department of Plant Agriculture, University of Guelph, Guelph, ON, Canada
- Virginia Tech, Alson H. Smith, Jr. Agricultural Research and Extension Center, Winchester, VA, USA
| | - L A Erland
- Gosling Research Institute for Plant Preservation, Department of Plant Agriculture, University of Guelph, Guelph, ON, Canada
| | - M R Shukla
- Gosling Research Institute for Plant Preservation, Department of Plant Agriculture, University of Guelph, Guelph, ON, Canada
| | - P K Saxena
- Gosling Research Institute for Plant Preservation, Department of Plant Agriculture, University of Guelph, Guelph, ON, Canada.
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36
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Baudin M, Hassan JA, Schreiber KJ, Lewis JD. Analysis of the ZAR1 Immune Complex Reveals Determinants for Immunity and Molecular Interactions. PLANT PHYSIOLOGY 2017; 174:2038-2053. [PMID: 28652264 PMCID: PMC5543953 DOI: 10.1104/pp.17.00441] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 06/22/2017] [Indexed: 05/06/2023]
Abstract
Plants depend on innate immunity to prevent disease. Plant pathogenic bacteria, like Pseudomonas syringae and Xanthomonas campestris, use the type III secretion system as a molecular syringe to inject type III secreted effector (T3SE) proteins in plants. The primary function of most T3SEs is to suppress immunity; however, the plant can evolve nucleotide-binding domain-leucine-rich repeat domain-containing proteins to recognize specific T3SEs. The AtZAR1 NLR induces strong defense responses against P. syringae and X. campestris The P. syringae T3SE HopZ1a is an acetyltransferase that acetylates the pseudokinase AtZED1 and triggers recognition by AtZAR1. However, little is known about the molecular mechanisms that lead to AtZAR1-induced immunity in response to HopZ1a. We established a transient expression system in Nicotiana benthamiana to study detailed interactions among HopZ1a, AtZED1, and AtZAR1. We show that the AtZAR1 immune pathway is conserved in N. benthamiana and identify AtZAR1 domains, and residues in AtZAR1 and AtZED1, that are important for immunity and protein-protein interactions in planta and in yeast (Saccharomyces cerevisiae). We show that the coiled-coil domain of AtZAR1 oligomerizes, and this domain acts as a signal to induce immunity. This detailed analysis of the AtZAR1-AtZED1 protein complex provides a better understanding of the immune signaling hub controlled by AtZAR1.
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Affiliation(s)
- Maël Baudin
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, California 94720
| | - Jana A Hassan
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, California 94720
| | - Karl J Schreiber
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, California 94720
| | - Jennifer D Lewis
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, California 94720
- Plant Gene Expression Center, U.S. Department of Agriculture, Albany, California 94710
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37
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Cerutti A, Jauneau A, Auriac MC, Lauber E, Martinez Y, Chiarenza S, Leonhardt N, Berthomé R, Noël LD. Immunity at Cauliflower Hydathodes Controls Systemic Infection by Xanthomonas campestris pv campestris. PLANT PHYSIOLOGY 2017; 174:700-716. [PMID: 28184011 PMCID: PMC5462019 DOI: 10.1104/pp.16.01852] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 02/06/2017] [Indexed: 05/20/2023]
Abstract
Hydathodes are water pores found on leaves of a wide range of vascular plants and are the sites of guttation. We report here on the detailed anatomy of cauliflower (Brassicaoleracea) and Arabidopsis (Arabidopsis thaliana) hydathodes. Hydathode surface presents pores resembling stomata giving access to large cavities. Beneath, the epithem is composed of a lacunar and highly vascularized parenchyma offering a direct connection between leaf surface and xylem vessels. Arabidopsis hydathode pores were responsive to ABA and light similar to stomata. The flg22 flagellin peptide, a well-characterized elicitor of plant basal immunity, did not induce closure of hydathode pores in contrast to stomata. Because hydathodes are natural infection routes for several pathogens, we investigated hydathode infection by the adapted vascular phytopathogenic bacterium Xanthomonas campestris pv campestris (Xcc), the causal agent of black rot disease of Brassicaceae. Microscopic observations of hydathodes six days postinoculation indicated a digestion of the epithem cells and a high bacterial multiplication. Postinvasive immunity was shown to limit pathogen growth in the epithem and is actively suppressed by the type III secretion system and its effector proteins. Altogether, these results give a detailed anatomic description of Brassicaceae hydathodes and highlight the efficient use of this tissue as an initial niche for subsequent vascular systemic dissemination of Xcc in distant plant tissues.
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Affiliation(s)
- Aude Cerutti
- LIPM, Université de Toulouse, INRA, CNRS, UPS, F-31326 Castanet-Tolosan, France (A.C., E.L., R.B., L.D.N.)
- Institut Fédératif de Recherche 3450, Plateforme Imagerie, Pôle de Biotechnologie Végétale, F-31326 Castanet-Tolosan, France (A.J., M.-C.A., Y.M.); and
- UMR7265, Laboratoire de Biologie du Développement des Plantes, Service de Biologie Végétale et de Microbiologie Environnementales, Institut de Biologie Environnementale et Biotechnologie, Centre National de la Recherche Scientifique-Commissariat à l'Energie Atomique-Université Aix-Marseille, F-13108 Saint Paul-Les-Durance, France (S.C., N.L.)
| | - Alain Jauneau
- LIPM, Université de Toulouse, INRA, CNRS, UPS, F-31326 Castanet-Tolosan, France (A.C., E.L., R.B., L.D.N.)
- Institut Fédératif de Recherche 3450, Plateforme Imagerie, Pôle de Biotechnologie Végétale, F-31326 Castanet-Tolosan, France (A.J., M.-C.A., Y.M.); and
- UMR7265, Laboratoire de Biologie du Développement des Plantes, Service de Biologie Végétale et de Microbiologie Environnementales, Institut de Biologie Environnementale et Biotechnologie, Centre National de la Recherche Scientifique-Commissariat à l'Energie Atomique-Université Aix-Marseille, F-13108 Saint Paul-Les-Durance, France (S.C., N.L.)
| | - Marie-Christine Auriac
- LIPM, Université de Toulouse, INRA, CNRS, UPS, F-31326 Castanet-Tolosan, France (A.C., E.L., R.B., L.D.N.)
- Institut Fédératif de Recherche 3450, Plateforme Imagerie, Pôle de Biotechnologie Végétale, F-31326 Castanet-Tolosan, France (A.J., M.-C.A., Y.M.); and
- UMR7265, Laboratoire de Biologie du Développement des Plantes, Service de Biologie Végétale et de Microbiologie Environnementales, Institut de Biologie Environnementale et Biotechnologie, Centre National de la Recherche Scientifique-Commissariat à l'Energie Atomique-Université Aix-Marseille, F-13108 Saint Paul-Les-Durance, France (S.C., N.L.)
| | - Emmanuelle Lauber
- LIPM, Université de Toulouse, INRA, CNRS, UPS, F-31326 Castanet-Tolosan, France (A.C., E.L., R.B., L.D.N.)
- Institut Fédératif de Recherche 3450, Plateforme Imagerie, Pôle de Biotechnologie Végétale, F-31326 Castanet-Tolosan, France (A.J., M.-C.A., Y.M.); and
- UMR7265, Laboratoire de Biologie du Développement des Plantes, Service de Biologie Végétale et de Microbiologie Environnementales, Institut de Biologie Environnementale et Biotechnologie, Centre National de la Recherche Scientifique-Commissariat à l'Energie Atomique-Université Aix-Marseille, F-13108 Saint Paul-Les-Durance, France (S.C., N.L.)
| | - Yves Martinez
- LIPM, Université de Toulouse, INRA, CNRS, UPS, F-31326 Castanet-Tolosan, France (A.C., E.L., R.B., L.D.N.)
- Institut Fédératif de Recherche 3450, Plateforme Imagerie, Pôle de Biotechnologie Végétale, F-31326 Castanet-Tolosan, France (A.J., M.-C.A., Y.M.); and
- UMR7265, Laboratoire de Biologie du Développement des Plantes, Service de Biologie Végétale et de Microbiologie Environnementales, Institut de Biologie Environnementale et Biotechnologie, Centre National de la Recherche Scientifique-Commissariat à l'Energie Atomique-Université Aix-Marseille, F-13108 Saint Paul-Les-Durance, France (S.C., N.L.)
| | - Serge Chiarenza
- LIPM, Université de Toulouse, INRA, CNRS, UPS, F-31326 Castanet-Tolosan, France (A.C., E.L., R.B., L.D.N.)
- Institut Fédératif de Recherche 3450, Plateforme Imagerie, Pôle de Biotechnologie Végétale, F-31326 Castanet-Tolosan, France (A.J., M.-C.A., Y.M.); and
- UMR7265, Laboratoire de Biologie du Développement des Plantes, Service de Biologie Végétale et de Microbiologie Environnementales, Institut de Biologie Environnementale et Biotechnologie, Centre National de la Recherche Scientifique-Commissariat à l'Energie Atomique-Université Aix-Marseille, F-13108 Saint Paul-Les-Durance, France (S.C., N.L.)
| | - Nathalie Leonhardt
- LIPM, Université de Toulouse, INRA, CNRS, UPS, F-31326 Castanet-Tolosan, France (A.C., E.L., R.B., L.D.N.)
- Institut Fédératif de Recherche 3450, Plateforme Imagerie, Pôle de Biotechnologie Végétale, F-31326 Castanet-Tolosan, France (A.J., M.-C.A., Y.M.); and
- UMR7265, Laboratoire de Biologie du Développement des Plantes, Service de Biologie Végétale et de Microbiologie Environnementales, Institut de Biologie Environnementale et Biotechnologie, Centre National de la Recherche Scientifique-Commissariat à l'Energie Atomique-Université Aix-Marseille, F-13108 Saint Paul-Les-Durance, France (S.C., N.L.)
| | - Richard Berthomé
- LIPM, Université de Toulouse, INRA, CNRS, UPS, F-31326 Castanet-Tolosan, France (A.C., E.L., R.B., L.D.N.)
- Institut Fédératif de Recherche 3450, Plateforme Imagerie, Pôle de Biotechnologie Végétale, F-31326 Castanet-Tolosan, France (A.J., M.-C.A., Y.M.); and
- UMR7265, Laboratoire de Biologie du Développement des Plantes, Service de Biologie Végétale et de Microbiologie Environnementales, Institut de Biologie Environnementale et Biotechnologie, Centre National de la Recherche Scientifique-Commissariat à l'Energie Atomique-Université Aix-Marseille, F-13108 Saint Paul-Les-Durance, France (S.C., N.L.)
| | - Laurent D Noël
- LIPM, Université de Toulouse, INRA, CNRS, UPS, F-31326 Castanet-Tolosan, France (A.C., E.L., R.B., L.D.N.);
- Institut Fédératif de Recherche 3450, Plateforme Imagerie, Pôle de Biotechnologie Végétale, F-31326 Castanet-Tolosan, France (A.J., M.-C.A., Y.M.); and
- UMR7265, Laboratoire de Biologie du Développement des Plantes, Service de Biologie Végétale et de Microbiologie Environnementales, Institut de Biologie Environnementale et Biotechnologie, Centre National de la Recherche Scientifique-Commissariat à l'Energie Atomique-Université Aix-Marseille, F-13108 Saint Paul-Les-Durance, France (S.C., N.L.)
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Li L, Li RF, Ming ZH, Lu GT, Tang JL. Identification of a novel type III secretion-associated outer membrane-bound protein from Xanthomonas campestris pv. campestris. Sci Rep 2017; 7:42724. [PMID: 28198457 PMCID: PMC5309889 DOI: 10.1038/srep42724] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 01/13/2017] [Indexed: 12/31/2022] Open
Abstract
Many bacterial pathogens employ the type III secretion system (T3SS) to translocate effector proteins into eukaryotic cells to overcome host defenses. To date, most of our knowledge about the T3SS molecular architecture comes from the studies on animal pathogens. In plant pathogens, nine Hrc proteins are believed to be structural components of the T3SS, of which HrcC and HrcJ form the outer and inner rings of the T3SS, respectively. Here, we demonstrated that a novel outer membrane-bound protein (HpaM) of Xanthomonas campestris pv. campestris is critical for the type III secretion and is structurally and functionally conserved in phytopathogenic Xanthomonas spp. We showed that the C-terminus of HpaM extends into the periplasm to interact physically with HrcJ and the middle part of HpaM interacts physically with HrcC. It is clear that the outer and inner rings compose the main basal body of the T3SS apparatus in animal pathogens. Therefore, we presume that HpaM may act as a T3SS structural component, or play a role in assisting assembling or affecting the stability of the T3SS apparatus. HpaM is a highly prevalent and specific protein in Xanthomonas spp., suggesting that the T3SS of Xanthomonas is distinctive in some aspects from other pathogens.
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Affiliation(s)
- Lei Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, China
| | - Rui-Fang Li
- Guangxi Key Laboratory of Biology for Crop Diseases and Insect Pests, Plant Protection Research Institute, Guangxi Academy of Agricultural Sciences, 174 Daxue Road, Nanning, Guangxi 530007, China
| | - Zhen-Hua Ming
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, China
| | - Guang-Tao Lu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, China
| | - Ji-Liang Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, China
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Schreiber KJ, Baudin M, Hassan JA, Lewis JD. Die another day: Molecular mechanisms of effector-triggered immunity elicited by type III secreted effector proteins. Semin Cell Dev Biol 2016; 56:124-133. [DOI: 10.1016/j.semcdb.2016.05.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 05/02/2016] [Indexed: 11/27/2022]
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40
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The Decoy Substrate of a Pathogen Effector and a Pseudokinase Specify Pathogen-Induced Modified-Self Recognition and Immunity in Plants. Cell Host Microbe 2015; 18:285-95. [DOI: 10.1016/j.chom.2015.08.004] [Citation(s) in RCA: 160] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 07/31/2015] [Accepted: 08/12/2015] [Indexed: 01/09/2023]
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41
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Mesarich CH, Bowen JK, Hamiaux C, Templeton MD. Repeat-containing protein effectors of plant-associated organisms. FRONTIERS IN PLANT SCIENCE 2015; 6:872. [PMID: 26557126 PMCID: PMC4617103 DOI: 10.3389/fpls.2015.00872] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 10/01/2015] [Indexed: 05/10/2023]
Abstract
Many plant-associated organisms, including microbes, nematodes, and insects, deliver effector proteins into the apoplast, vascular tissue, or cell cytoplasm of their prospective hosts. These effectors function to promote colonization, typically by altering host physiology or by modulating host immune responses. The same effectors however, can also trigger host immunity in the presence of cognate host immune receptor proteins, and thus prevent colonization. To circumvent effector-triggered immunity, or to further enhance host colonization, plant-associated organisms often rely on adaptive effector evolution. In recent years, it has become increasingly apparent that several effectors of plant-associated organisms are repeat-containing proteins (RCPs) that carry tandem or non-tandem arrays of an amino acid sequence or structural motif. In this review, we highlight the diverse roles that these repeat domains play in RCP effector function. We also draw attention to the potential role of these repeat domains in adaptive evolution with regards to RCP effector function and the evasion of effector-triggered immunity. The aim of this review is to increase the profile of RCP effectors from plant-associated organisms.
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Affiliation(s)
- Carl H. Mesarich
- School of Biological Sciences, The University of AucklandAuckland, New Zealand
- Host–Microbe Interactions, Bioprotection, The New Zealand Institute for Plant & Food Research LtdAuckland, New Zealand
- *Correspondence: Carl H. Mesarich
| | - Joanna K. Bowen
- Host–Microbe Interactions, Bioprotection, The New Zealand Institute for Plant & Food Research LtdAuckland, New Zealand
| | - Cyril Hamiaux
- Human Responses, The New Zealand Institute for Plant & Food Research LimitedAuckland, New Zealand
| | - Matthew D. Templeton
- School of Biological Sciences, The University of AucklandAuckland, New Zealand
- Host–Microbe Interactions, Bioprotection, The New Zealand Institute for Plant & Food Research LtdAuckland, New Zealand
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42
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Muñoz Bodnar A, Cruz Gómez LM, Bernal A, Szurek B, López Carrascal CE. COMPARING INOCULATION METHODS TO EVALUATE THE GROWTH OF Xanthomonas axonopodis pv. manihotis ON CASSAVA PLANTS. ACTA BIOLÓGICA COLOMBIANA 2014. [DOI: 10.15446/abc.v20n2.43130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
<p class="ecxmsonormal"><em>Xanthomonas axonopodis </em>pv. manihotis (<em>Xam</em>) is the causal agent of cassava bacterial blight (CBB), a major disease for cassava crops in South America and Africa. Until now the development of the disease is measured via AUDPC (Area Under Disease Progress Curve) but no reliable quantitative methods are available probably due to high variability of bacterial growth <em>in planta</em>. To establish an accurate method for bacterial quantification during the course of <em>Xam</em> infection within the host tissues, we analyzed bacterial populations upon stem and leaf-puncturing as well as leaf-clipping of cassava varieties MCOL1522 and SG107-35 challenged with the virulent <em>Xam</em> strain CIO151. Here, we show that the movement of bacteria along the tissues and especially in leaves is stochastic. Moreover, we were able to demonstrate differential growth of virulent <em>Xam</em> strain CIO151 upon stem-puncturing and quantification of bacteria 6 cm. away from the inoculation point of two varieties displaying contrasting levels of susceptibility.</p><p class="ecxmsonormal"><strong>RESUMEN</strong></p><p class="ecxmsonormal"><!--[if gte mso 9]><xml> <o:OfficeDocumentSettings> <o:AllowPNG/> </o:OfficeDocumentSettings> </xml><![endif]--></p><p class="msocomoff" align="left"><!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:TrackMoves/> <w:TrackFormatting/> <w:HyphenationZone>21</w:HyphenationZone> <w:PunctuationKerning/> <w:ValidateAgainstSchemas/> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:DoNotPromoteQF/> <w:LidThemeOther>ES-CO</w:LidThemeOther> <w:LidThemeAsian>X-NONE</w:LidThemeAsian> 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lang="X-NONE">Xanthomonas axonopodis </span></em><span lang="X-NONE">pv. manihotis<em style="mso-bidi-font-style: normal;"> (Xam)</em> es el agente causal del tizón bacteriano de la yuca, una de las principales enfermedades de los cultivos de yuca en América del Sur y África. Hasta ahora, el desarrollo de la enfermedad se mide a través de AUDPC <em style="mso-bidi-font-style: normal;">(Area<span style="mso-spacerun: yes;"> </span>Under Disease Progress curve)</em>, pero no hay disponibles métodos cuantitativos fiables,<span style="mso-spacerun: yes;"> </span>esto debido posiblemente a la alta variabilidad del crecimiento bacteriano en la planta. Para establecer un método exacto para la cuantificación bacteriana durante el curso de la infección <em style="mso-bidi-font-style: normal;">Xam </em>dentro de los tejidos del huésped, se analizaron las poblaciones de bacterias sobre tallo y hojas, así como corte de hojas de las <a style="mso-comment-reference: as_1; mso-comment-date: 20141102T2035;">variedades de yuca</a></span><span lang="X-NONE">MCOL1522 y SG107-35 con la cepa virulenta CIO151 <em style="mso-bidi-font-style: normal;">Xam.</em> <a style="mso-comment-reference: as_2; mso-comment-date: 20141102T2035;">En esta investigación se </a></span><span lang="X-NONE">muestra que el movimiento de las bacterias a lo largo de los tejidos y especialmente en las hojas es estocástico. Por otra parte, hemos podido demostrar el crecimiento diferencial de la cepa virulenta<span style="mso-spacerun: yes;"> </span><em style="mso-bidi-font-style: normal;">Xam</em> CIO151 tras la punción al tallo y la cuantificación de la bacteria a 6 cm de distancia del punto de inoculación de dos variedades que presentan niveles contrastantes de susceptibilidad.</span></p><p class="ecxmsonormal"> </p>
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Jiang GF, Jiang BL, Yang M, Liu S, Liu J, Liang XX, Bai XF, Tang DJ, Lu GT, He YQ, Yu DQ, Tang JL. Establishment of an inducing medium for type III effector secretion in Xanthomonas campestris pv. campestris. Braz J Microbiol 2014; 44:945-52. [PMID: 24516463 PMCID: PMC3910216 DOI: 10.1590/s1517-83822013000300045] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2012] [Accepted: 09/10/2012] [Indexed: 11/21/2022] Open
Abstract
It is well known that the type III secretion system (T3SS) and type III (T3) effectors are essential for the pathogenicity of most bacterial phytopathogens and that the expression of T3SS and T3 effectors is suppressed in rich media but induced in minimal media and plants. To facilitate in-depth studies on T3SS and T3 effectors, it is crucial to establish a medium for T3 effector expression and secretion. Xanthomonas campestris pv. campestris (Xcc) is a model bacterium for studying plant-pathogen interactions. To date no medium for Xcc T3 effector secretion has been defined. Here, we compared four minimal media (MME, MMX, XVM2, and XOM2) which are reported for T3 expression induction in Xanthomonas spp. and found that MME is most efficient for expression and secretion of Xcc T3 effectors. By optimization of carbon and nitrogen sources and pH value based on MME, we established XCM1 medium, which is about 3 times stronger than MME for Xcc T3 effectors secretion. We further optimized the concentration of phosphate, calcium, and magnesium in XCM1 and found that XCM1 with a lower concentration of magnesium (renamed as XCM2) is about 10 times as efficient as XCM1 (meanwhile, about 30 times stronger than MME). Thus, we established an inducing medium XCM2 which is preferred for T3 effector secretion in Xcc.
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Affiliation(s)
- Guo-Feng Jiang
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, China. ; Graduate School of Chinese Academy of Sciences, Beijing, China
| | - Bo-Le Jiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, and College of Life Science and Technology, Guangxi University, Nanning, Guangxi, China
| | - Mei Yang
- School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi, China
| | - San Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, and College of Life Science and Technology, Guangxi University, Nanning, Guangxi, China
| | - Jiao Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, and College of Life Science and Technology, Guangxi University, Nanning, Guangxi, China
| | - Xiao-Xia Liang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, and College of Life Science and Technology, Guangxi University, Nanning, Guangxi, China
| | - Xian-Fang Bai
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, and College of Life Science and Technology, Guangxi University, Nanning, Guangxi, China
| | - Dong-Jie Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, and College of Life Science and Technology, Guangxi University, Nanning, Guangxi, China
| | - Guang-Tao Lu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, and College of Life Science and Technology, Guangxi University, Nanning, Guangxi, China
| | - Yong-Qiang He
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, and College of Life Science and Technology, Guangxi University, Nanning, Guangxi, China
| | - Di-Qiu Yu
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Ji-Liang Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, and College of Life Science and Technology, Guangxi University, Nanning, Guangxi, China
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Guy E, Lautier M, Chabannes M, Roux B, Lauber E, Arlat M, Noël LD. xopAC-triggered immunity against Xanthomonas depends on Arabidopsis receptor-like cytoplasmic kinase genes PBL2 and RIPK. PLoS One 2013; 8:e73469. [PMID: 23951354 PMCID: PMC3739749 DOI: 10.1371/journal.pone.0073469] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 07/23/2013] [Indexed: 12/22/2022] Open
Abstract
Xanthomonas campestris pv. campestris (Xcc) colonizes the vascular system of Brassicaceae and ultimately causes black rot. In susceptible Arabidopsis plants, XopAC type III effector inhibits by uridylylation positive regulators of the PAMP-triggered immunity such as the receptor-like cytoplasmic kinases (RLCK) BIK1 and PBL1. In the resistant ecotype Col-0, xopAC is a major avirulence gene of Xcc. In this study, we show that both the RLCK interaction domain and the uridylyl transferase domain of XopAC are required for avirulence. Furthermore, xopAC can also confer avirulence to both the vascular pathogen Ralstonia solanacearum and the mesophyll-colonizing pathogen Pseudomonas syringae indicating that xopAC-specified effector-triggered immunity is not specific to the vascular system. In planta, XopAC-YFP fusions are localized at the plasma membrane suggesting that XopAC might interact with membrane-localized proteins. Eight RLCK of subfamily VII predicted to be localized at the plasma membrane and interacting with XopAC in yeast two-hybrid assays have been isolated. Within this subfamily, PBL2 and RIPK RLCK genes but not BIK1 are important for xopAC-specified effector-triggered immunity and Arabidopsis resistance to Xcc.
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Affiliation(s)
- Endrick Guy
- INRA, Laboratoire des Interactions Plantes Micro-organismes (LIPM), UMR 441, Castanet-Tolosan, France
- CNRS, Laboratoire des Interactions Plantes Micro-organismes (LIPM), UMR 2594, Castanet-Tolosan, France
| | - Martine Lautier
- INRA, Laboratoire des Interactions Plantes Micro-organismes (LIPM), UMR 441, Castanet-Tolosan, France
- CNRS, Laboratoire des Interactions Plantes Micro-organismes (LIPM), UMR 2594, Castanet-Tolosan, France
- Université de Toulouse, Université Paul Sabatier, Toulouse, France
| | - Matthieu Chabannes
- INRA, Laboratoire des Interactions Plantes Micro-organismes (LIPM), UMR 441, Castanet-Tolosan, France
- CNRS, Laboratoire des Interactions Plantes Micro-organismes (LIPM), UMR 2594, Castanet-Tolosan, France
| | - Brice Roux
- INRA, Laboratoire des Interactions Plantes Micro-organismes (LIPM), UMR 441, Castanet-Tolosan, France
- CNRS, Laboratoire des Interactions Plantes Micro-organismes (LIPM), UMR 2594, Castanet-Tolosan, France
| | - Emmanuelle Lauber
- INRA, Laboratoire des Interactions Plantes Micro-organismes (LIPM), UMR 441, Castanet-Tolosan, France
- CNRS, Laboratoire des Interactions Plantes Micro-organismes (LIPM), UMR 2594, Castanet-Tolosan, France
| | - Matthieu Arlat
- INRA, Laboratoire des Interactions Plantes Micro-organismes (LIPM), UMR 441, Castanet-Tolosan, France
- CNRS, Laboratoire des Interactions Plantes Micro-organismes (LIPM), UMR 2594, Castanet-Tolosan, France
- Université de Toulouse, Université Paul Sabatier, Toulouse, France
| | - Laurent D. Noël
- INRA, Laboratoire des Interactions Plantes Micro-organismes (LIPM), UMR 441, Castanet-Tolosan, France
- CNRS, Laboratoire des Interactions Plantes Micro-organismes (LIPM), UMR 2594, Castanet-Tolosan, France
- * E-mail:
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Li RF, Lu GT, Li L, Su HZ, Feng GF, Chen Y, He YQ, Jiang BL, Tang DJ, Tang JL. Identification of a putative cognate sensor kinase for the two-component response regulator HrpG, a key regulator controlling the expression of the hrp genes in Xanthomonas campestris pv. campestris. Environ Microbiol 2013; 16:2053-71. [PMID: 23906314 DOI: 10.1111/1462-2920.12207] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2013] [Revised: 06/10/2013] [Accepted: 06/30/2013] [Indexed: 11/29/2022]
Abstract
The bacterial phytopathogen Xanthomonas campestris pv. campestris (Xcc) relies on the hrp (hypersensitive response and pathogenicity) genes to cause disease and induce hypersensitive response (HR). The hrp genes of bacterial phytopathogens are divided into two groups. Xcc hrp genes belong to group II. It has long been known that the group II hrp genes are activated by an AraC-type transcriptional regulator whose expression is controlled by a two-component system (TCS) response regulator (named HrpG in Xcc). However, no cognate sensor kinase has yet been identified. Here, we present evidence showing that the Xcc open-reading frame XC_3670 encodes a TCS sensor kinase (named HpaS). Mutation of hpaS almost completely abolished the HR induction and virulence. Bacterial two-hybrid and protein pull-down assays revealed that HpaS physically interacted with HrpG. Phos-tag™ SDS-PAGE analysis showed that mutation in hpaS reduced markedly the phosphorylation of HrpG in vivo. These data suggest that HpaS and HrpG are most likely to form a TCS. We also showed that XC_3669 (named hpaR2), which is adjacent to hpaS and encodes a putative TCS response regulator, is required for full virulence but not HR induction. HpaR2 also physically interacted with HpaS, suggesting that HpaS may also form another TCS with HpaR2.
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Affiliation(s)
- Rui-Fang Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004, China
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Natural genetic variation of Xanthomonas campestris pv. campestris pathogenicity on arabidopsis revealed by association and reverse genetics. mBio 2013. [PMID: 23736288 DOI: 10.1128/mbio.00538-12.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
ABSTRACT The pathogenic bacterium Xanthomonas campestris pv. campestris, the causal agent of black rot of Brassicaceae, manipulates the physiology and the innate immunity of its hosts. Association genetic and reverse-genetic analyses of a world panel of 45 X. campestris pv. campestris strains were used to gain understanding of the genetic basis of the bacterium's pathogenicity to Arabidopsis thaliana. We found that the compositions of the minimal predicted type III secretome varied extensively, with 18 to 28 proteins per strain. There were clear differences in aggressiveness of those X. campestris pv. campestris strains on two Arabidopsis natural accessions. We identified 3 effector genes (xopAC, xopJ5, and xopAL2) and 67 amplified fragment length polymorphism (AFLP) markers that were associated with variations in disease symptoms. The nature and distribution of the AFLP markers remain to be determined, but we observed a low linkage disequilibrium level between predicted effectors and other significant markers, suggesting that additional genetic factors make a meaningful contribution to pathogenicity. Mutagenesis of type III effectors in X. campestris pv. campestris confirmed that xopAC functions as both a virulence and an avirulence gene in Arabidopsis and that xopAM functions as a second avirulence gene on plants of the Col-0 ecotype. However, we did not detect the effect of any other effector in the X. campestris pv. campestris 8004 strain, likely due to other genetic background effects. These results highlight the complex genetic basis of pathogenicity at the pathovar level and encourage us to challenge the agronomical relevance of some virulence determinants identified solely in model strains. IMPORTANCE The identification and understanding of the genetic determinants of bacterial virulence are essential to be able to design efficient protection strategies for infected plants. The recent availability of genomic resources for a limited number of pathogen isolates and host genotypes has strongly biased our research toward genotype-specific approaches. Indeed, these do not consider the natural variation in both pathogens and hosts, so their applied relevance should be challenged. In our study, we exploited the genetic diversity of Xanthomonas campestris pv. campestris, the causal agent of black rot on Brassicaceae (e.g., cabbage), to mine for pathogenicity determinants. This work evidenced the contribution of known and unknown loci to pathogenicity relevant at the pathovar level and identified these virulence determinants as prime targets for breeding resistance to X. campestris pv. campestris in Brassicaceae.
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Natural genetic variation of Xanthomonas campestris pv. campestris pathogenicity on arabidopsis revealed by association and reverse genetics. mBio 2013; 4:e00538-12. [PMID: 23736288 PMCID: PMC3685212 DOI: 10.1128/mbio.00538-12] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
ABSTRACT The pathogenic bacterium Xanthomonas campestris pv. campestris, the causal agent of black rot of Brassicaceae, manipulates the physiology and the innate immunity of its hosts. Association genetic and reverse-genetic analyses of a world panel of 45 X. campestris pv. campestris strains were used to gain understanding of the genetic basis of the bacterium's pathogenicity to Arabidopsis thaliana. We found that the compositions of the minimal predicted type III secretome varied extensively, with 18 to 28 proteins per strain. There were clear differences in aggressiveness of those X. campestris pv. campestris strains on two Arabidopsis natural accessions. We identified 3 effector genes (xopAC, xopJ5, and xopAL2) and 67 amplified fragment length polymorphism (AFLP) markers that were associated with variations in disease symptoms. The nature and distribution of the AFLP markers remain to be determined, but we observed a low linkage disequilibrium level between predicted effectors and other significant markers, suggesting that additional genetic factors make a meaningful contribution to pathogenicity. Mutagenesis of type III effectors in X. campestris pv. campestris confirmed that xopAC functions as both a virulence and an avirulence gene in Arabidopsis and that xopAM functions as a second avirulence gene on plants of the Col-0 ecotype. However, we did not detect the effect of any other effector in the X. campestris pv. campestris 8004 strain, likely due to other genetic background effects. These results highlight the complex genetic basis of pathogenicity at the pathovar level and encourage us to challenge the agronomical relevance of some virulence determinants identified solely in model strains. IMPORTANCE The identification and understanding of the genetic determinants of bacterial virulence are essential to be able to design efficient protection strategies for infected plants. The recent availability of genomic resources for a limited number of pathogen isolates and host genotypes has strongly biased our research toward genotype-specific approaches. Indeed, these do not consider the natural variation in both pathogens and hosts, so their applied relevance should be challenged. In our study, we exploited the genetic diversity of Xanthomonas campestris pv. campestris, the causal agent of black rot on Brassicaceae (e.g., cabbage), to mine for pathogenicity determinants. This work evidenced the contribution of known and unknown loci to pathogenicity relevant at the pathovar level and identified these virulence determinants as prime targets for breeding resistance to X. campestris pv. campestris in Brassicaceae.
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Yadeta KA, J. Thomma BPH. The xylem as battleground for plant hosts and vascular wilt pathogens. FRONTIERS IN PLANT SCIENCE 2013; 4:97. [PMID: 23630534 PMCID: PMC3632776 DOI: 10.3389/fpls.2013.00097] [Citation(s) in RCA: 244] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2012] [Accepted: 03/28/2013] [Indexed: 05/19/2023]
Abstract
Vascular wilts are among the most destructive plant diseases that occur in annual crops as well as in woody perennials. These diseases are generally caused by soil-borne bacteria, fungi, and oomycetes that infect through the roots and enter the water-conducting xylem vessels where they proliferate and obstruct the transportation of water and minerals. As a consequence, leaves wilt and die, which may lead to impairment of the whole plant and eventually to death of the plant. Cultural, chemical, and biological measures to control this group of plant pathogens are generally ineffective, and the most effective control strategy is the use of genetic resistance. Owing to the fact that vascular wilt pathogens live deep in the interior of their host plants, studies into the biology of vascular pathogens are complicated. However, to design novel strategies to combat vascular wilt diseases, understanding the (molecular) biology of vascular pathogens and the molecular mechanisms underlying plant defense against these pathogens is crucial. In this review, we discuss the current knowledge on interactions of vascular wilt pathogens with their host plants, with emphasis on host defense responses against this group of pathogens.
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Affiliation(s)
- Koste A. Yadeta
- Laboratory of Phytopathology, Wageningen UniversityWageningen, Netherlands
| | - Bart P. H. J. Thomma
- Laboratory of Phytopathology, Wageningen UniversityWageningen, Netherlands
- Centre for BioSystems GenomicsWageningen, Netherlands
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Ho YP, Tan CM, Li MY, Lin H, Deng WL, Yang JY. The AvrB_AvrC domain of AvrXccC of Xanthomonas campestris pv. campestris is required to elicit plant defense responses and manipulate ABA homeostasis. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2013; 26:419-30. [PMID: 23252460 DOI: 10.1094/mpmi-06-12-0164-r] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Plant disease induced by Xanthomonas campestris pv. campestris depends on type III effectors but the molecular basis is poorly understood. Here, AvrXccC8004 was characterized, and it was found that the AvrB_AvrC domain was essential and sufficient to elicit defense responses in an Arabidopsis-resistant ecotype (Col-0). An upregulation of genes in responding to the AvrB_AvrC domain of AvrXccC8004 was shown in a profile of host gene expression. The molecular changes were correlated with morphological changes observed in phenotypic and ultrastructural characterizations. Interestingly, the abscisic acid (ABA)-signaling pathway was also a prominent target for the AvrB_AvrC domain of AvrXccC8004. The highly elicited NCED5, encoding a key enzyme of ABA biosynthesis, was increased in parallel with ABA levels in AvrXccC8004 transgenic plants. Consistently, the X. campestris pv. campestris 8004 ΔavrXccC mutant was severely impaired in the ability to manipulate the accumulation of ABA and induction of ABA-related genes in challenged leaves. Moreover, exogenous application of ABA also enhanced the susceptibility of Arabidopsis to the X. campestris pv. campestris strains. These results indicate that the AvrB_AvrC domain of AvrXccC8004 alone has the activity to manipulate ABA homeostasis, which plays an important role in regulating the interactions of X. campestris pv. campestris and Arabidopsis.
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Affiliation(s)
- Yi-Ping Ho
- Institute of Biochemistry, National ChungHsing University, Taichung, Taiwan
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50
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Liu W, Yu YH, Cao SY, Niu XN, Jiang W, Liu GF, Jiang BL, Tang DJ, Lu GT, He YQ, Tang JL. Transcriptome profiling of Xanthomonas campestris pv. campestris grown in minimal medium MMX and rich medium NYG. Res Microbiol 2013; 164:466-79. [PMID: 23470514 DOI: 10.1016/j.resmic.2013.02.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 02/14/2013] [Indexed: 12/14/2022]
Abstract
Xanthomonas campestris pathovar campestris (Xcc) is the causal agent of black rot disease in cruciferous plants worldwide. Although the complete genomes of several Xcc strains have been determined, the gene expression and regulation mechanisms in this pathogen are far from clear. In this work, transcriptome profiling of Xcc 8004 grown in MMX medium (minimal medium for Xanthomonas campestris) and NYG medium (peptone yeast glycerol medium) were investigated by RNA-Seq. Using the Illumina HiSeq 2000 platform, a total of 26,514,630 reads (90 nt in average) were generated, of which 15,708,478 reads mapped uniquely to coding regions of Xcc 8004 genome. Of the 4273 annotated protein-coding genes of Xcc 8004, 629 were found differentially expressed in Xcc grown in MMX and NYG. Of the differentially expressed genes, 495 were up-regulated and 134 were down-regulated in MMX. The MMX-induced genes are mainly involved in amino acid metabolism, transport systems, atypical condition adaptation and pathogenicity, especially the type III secretion system, while the MMX-repressed genes are mainly involved in chemotaxis and degradation of small molecules. The global transcriptome analyzes of Xcc 8004 grown in MMX and NYG might facilitate the gene functional characterization of this phytopathogenic bacterium.
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Affiliation(s)
- Wei Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, Guangxi 530004, China
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