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Islam T, Haque MA, Barai HR, Istiaq A, Kim JJ. Antibiotic Resistance in Plant Pathogenic Bacteria: Recent Data and Environmental Impact of Unchecked Use and the Potential of Biocontrol Agents as an Eco-Friendly Alternative. PLANTS (BASEL, SWITZERLAND) 2024; 13:1135. [PMID: 38674544 PMCID: PMC11054394 DOI: 10.3390/plants13081135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 04/15/2024] [Accepted: 04/17/2024] [Indexed: 04/28/2024]
Abstract
The economic impact of phytopathogenic bacteria on agriculture is staggering, costing billions of US dollars globally. Pseudomonas syringae is the top most phytopathogenic bacteria, having more than 60 pathovars, which cause bacteria speck in tomatoes, halo blight in beans, and so on. Although antibiotics or a combination of antibiotics are used to manage infectious diseases in plants, they are employed far less in agriculture compared to human and animal populations. Moreover, the majority of antibiotics used in plants are immediately washed away, leading to environmental damage to ecosystems and food chains. Due to the serious risk of antibiotic resistance (AR) and the potential for environmental contamination with antibiotic residues and resistance genes, the use of unchecked antibiotics against phytopathogenic bacteria is not advisable. Despite the significant concern regarding AR in the world today, there are inadequate and outdated data on the AR of phytopathogenic bacteria. This review presents recent AR data on plant pathogenic bacteria (PPB), along with their environmental impact. In light of these findings, we suggest the use of biocontrol agents as a sustainable, eco-friendly, and effective alternative to controlling phytopathogenic bacteria.
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Affiliation(s)
- Tarequl Islam
- Department of Microbiology, Noakhali Science and Technology University, Sonapur, Noakhali 3814, Bangladesh;
| | - Md Azizul Haque
- Department of Biotechnology, Yeungnam University, Gyeongsan 38541, Gyeongbuk, Republic of Korea;
| | - Hasi Rani Barai
- School of Mechanical and IT Engineering, Yeungnam University, Gyeongsan 38541, Gyeongbuk, Republic of Korea;
| | - Arif Istiaq
- Department of Pediatrics, Division of Genetics and Genomic Medicine, Washington University School of Medicine, St Louis, MO 63110-1010, USA
| | - Jong-Joo Kim
- Department of Biotechnology, Yeungnam University, Gyeongsan 38541, Gyeongbuk, Republic of Korea;
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2
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Wang MY, Chen JB, Wu R, Guo HL, Chen Y, Li ZJ, Wei LY, Liu C, He SF, Du MD, Guo YL, Peng YL, Jones JDG, Weigel D, Huang JH, Zhu WS. The plant immune receptor SNC1 monitors helper NLRs targeted by a bacterial effector. Cell Host Microbe 2023; 31:1792-1803.e7. [PMID: 37944492 DOI: 10.1016/j.chom.2023.10.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 09/01/2023] [Accepted: 10/06/2023] [Indexed: 11/12/2023]
Abstract
Plants deploy intracellular receptors to counteract pathogen effectors that suppress cell-surface-receptor-mediated immunity. To what extent pathogens manipulate intracellular receptor-mediated immunity, and how plants tackle such manipulation, remains unknown. Arabidopsis thaliana encodes three similar ADR1 class helper nucleotide-binding domain leucine-rich repeat receptors (ADR1, ADR1-L1, and ADR1-L2), which are crucial in plant immunity initiated by intracellular receptors. Here, we report that Pseudomonas syringae effector AvrPtoB suppresses ADR1-L1- and ADR1-L2-mediated cell death. ADR1, however, evades such suppression by diversifying into two ubiquitination sites targeted by AvrPtoB. The intracellular sensor SNC1 interacts with and guards the CCR domains of ADR1-L1/L2. Removal of ADR1-L1/L2 or delivery of AvrPtoB activates SNC1, which then signals through ADR1 to trigger immunity. Our work elucidates the long-sought-after function of SNC1 in defense, and also how plants can use dual strategies, sequence diversification, and a multi-layered guard-guardee system, to counteract pathogen's attack on core immunity functions.
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Affiliation(s)
- Ming-Yu Wang
- Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Ministry of Agriculture and Rural Affairs, and College of Plant Protection, State Key Laboratory of Maize Bio-breeding, China Agricultural University, Beijing 100193, China
| | - Jun-Bin Chen
- Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Ministry of Agriculture and Rural Affairs, and College of Plant Protection, State Key Laboratory of Maize Bio-breeding, China Agricultural University, Beijing 100193, China
| | - Rui Wu
- Department of Molecular Biology, Max Planck Institute for Biology Tübingen, 72076 Tübingen, Germany
| | - Hai-Long Guo
- Key Laboratory of Pest Monitoring and Green Management, Ministry of Agriculture and Rural Affairs, and College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Yan Chen
- Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Ministry of Agriculture and Rural Affairs, and College of Plant Protection, State Key Laboratory of Maize Bio-breeding, China Agricultural University, Beijing 100193, China
| | - Zhen-Ju Li
- Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Ministry of Agriculture and Rural Affairs, and College of Plant Protection, State Key Laboratory of Maize Bio-breeding, China Agricultural University, Beijing 100193, China
| | - Lu-Yang Wei
- Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Ministry of Agriculture and Rural Affairs, and College of Plant Protection, State Key Laboratory of Maize Bio-breeding, China Agricultural University, Beijing 100193, China
| | - Chuang Liu
- Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Ministry of Agriculture and Rural Affairs, and College of Plant Protection, State Key Laboratory of Maize Bio-breeding, China Agricultural University, Beijing 100193, China
| | - Sheng-Feng He
- Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Ministry of Agriculture and Rural Affairs, and College of Plant Protection, State Key Laboratory of Maize Bio-breeding, China Agricultural University, Beijing 100193, China
| | - Mei-Da Du
- Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Ministry of Agriculture and Rural Affairs, and College of Plant Protection, State Key Laboratory of Maize Bio-breeding, China Agricultural University, Beijing 100193, China
| | - Ya-Long Guo
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - You-Liang Peng
- Key Laboratory of Pest Monitoring and Green Management, Ministry of Agriculture and Rural Affairs, and College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Jonathan D G Jones
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Detlef Weigel
- Department of Molecular Biology, Max Planck Institute for Biology Tübingen, 72076 Tübingen, Germany; Institute for Bioinformatics and Medical Informatics, University of Tübingen, Tübingen, Germany
| | - Jian-Hua Huang
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK.
| | - Wang-Sheng Zhu
- Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Ministry of Agriculture and Rural Affairs, and College of Plant Protection, State Key Laboratory of Maize Bio-breeding, China Agricultural University, Beijing 100193, China.
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3
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Rufián JS, Rueda-Blanco J, Beuzón CR, Ruiz-Albert J. Suppression of NLR-mediated plant immune detection by bacterial pathogens. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:6069-6088. [PMID: 37429579 PMCID: PMC10575702 DOI: 10.1093/jxb/erad246] [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: 04/17/2023] [Accepted: 07/10/2023] [Indexed: 07/12/2023]
Abstract
The plant immune system is constituted of two functionally interdependent branches that provide the plant with an effective defense against microbial pathogens. They can be considered separate since one detects extracellular pathogen-associated molecular patterns by means of receptors on the plant surface, while the other detects pathogen-secreted virulence effectors via intracellular receptors. Plant defense depending on both branches can be effectively suppressed by host-adapted microbial pathogens. In this review we focus on bacterially driven suppression of the latter, known as effector-triggered immunity (ETI) and dependent on diverse NOD-like receptors (NLRs). We examine how some effectors secreted by pathogenic bacteria carrying type III secretion systems can be subject to specific NLR-mediated detection, which can be evaded by the action of additional co-secreted effectors (suppressors), implying that virulence depends on the coordinated action of the whole repertoire of effectors of any given bacterium and their complex epistatic interactions within the plant. We consider how ETI activation can be avoided by using suppressors to directly alter compromised co-secreted effectors, modify plant defense-associated proteins, or occasionally both. We also comment on the potential assembly within the plant cell of multi-protein complexes comprising both bacterial effectors and defense protein targets.
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Affiliation(s)
- José S Rufián
- Instituto de Hortofruticultura Subtropical y Mediterránea ‘La Mayora’, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Depto. Biología Celular, Genética y Fisiología, Málaga, Spain
| | | | - Carmen R Beuzón
- Instituto de Hortofruticultura Subtropical y Mediterránea ‘La Mayora’, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Depto. Biología Celular, Genética y Fisiología, Málaga, Spain
| | - Javier Ruiz-Albert
- Instituto de Hortofruticultura Subtropical y Mediterránea ‘La Mayora’, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Depto. Biología Celular, Genética y Fisiología, Málaga, Spain
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Li P, Li W, Zhou X, Situ J, Xie L, Xi P, Yang B, Kong G, Jiang Z. Peronophythora litchii RXLR effector P. litchii avirulence homolog 202 destabilizes a host ethylene biosynthesis enzyme. PLANT PHYSIOLOGY 2023; 193:756-774. [PMID: 37232407 DOI: 10.1093/plphys/kiad311] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 02/24/2023] [Indexed: 05/27/2023]
Abstract
Oomycete pathogens can secrete hundreds of effectors into plant cells to interfere with the plant immune system during infection. Here, we identified a Arg-X-Leu-Arg (RXLR) effector protein from the most destructive pathogen of litchi (Litchi chinensis Sonn.), Peronophythora litchii, and named it P. litchii avirulence homolog 202 (PlAvh202). PlAvh202 could suppress cell death triggered by infestin 1 or avirulence protein 3a/resistance protein 3a in Nicotiana benthamiana and was essential for P. litchii virulence. In addition, PlAvh202 suppressed plant immune responses and promoted the susceptibility of N. benthamiana to Phytophthora capsici. Further research revealed that PlAvh202 could suppress ethylene (ET) production by targeting and destabilizing plant S-adenosyl-L-methionine synthetase (SAMS), a key enzyme in the ET biosynthesis pathway, in a 26S proteasome-dependent manner without affecting its expression. Transient expression of LcSAMS3 induced ET production and enhanced plant resistance, whereas inhibition of ET biosynthesis promoted P. litchii infection, supporting that litchi SAMS (LcSAMS) and ET positively regulate litchi immunity toward P. litchii. Overall, these findings highlight that SAMS can be targeted by the oomycete RXLR effector to manipulate ET-mediated plant immunity.
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Affiliation(s)
- Peng Li
- Guangdong Key Laboratory of Microbial Signals and Disease Control/Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Wen Li
- Guangdong Key Laboratory of Microbial Signals and Disease Control/Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Xiaofan Zhou
- Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China
| | - Junjian Situ
- Guangdong Key Laboratory of Microbial Signals and Disease Control/Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Lizhu Xie
- Guangdong Key Laboratory of Microbial Signals and Disease Control/Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Pinggen Xi
- Guangdong Key Laboratory of Microbial Signals and Disease Control/Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Bo Yang
- College of Grassland Science/Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - Guanghui Kong
- Guangdong Key Laboratory of Microbial Signals and Disease Control/Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Zide Jiang
- Guangdong Key Laboratory of Microbial Signals and Disease Control/Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
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5
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Todd JNA, Carreón-Anguiano KG, Islas-Flores I, Canto-Canché B. Microbial Effectors: Key Determinants in Plant Health and Disease. Microorganisms 2022; 10:1980. [PMID: 36296254 PMCID: PMC9610748 DOI: 10.3390/microorganisms10101980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 09/27/2022] [Accepted: 09/29/2022] [Indexed: 11/17/2022] Open
Abstract
Effectors are small, secreted molecules that alter host cell structure and function, thereby facilitating infection or triggering a defense response. Effectoromics studies have focused on effectors in plant-pathogen interactions, where their contributions to virulence are determined in the plant host, i.e., whether the effector induces resistance or susceptibility to plant disease. Effector molecules from plant pathogenic microorganisms such as fungi, oomycetes and bacteria are major disease determinants. Interestingly, the effectors of non-pathogenic plant organisms such as endophytes display similar functions but have different outcomes for plant health. Endophyte effectors commonly aid in the establishment of mutualistic interactions with the plant and contribute to plant health through the induction of systemic resistance against pathogens, while pathogenic effectors mainly debilitate the plant's immune response, resulting in the establishment of disease. Effectors of plant pathogens as well as plant endophytes are tools to be considered in effectoromics for the development of novel strategies for disease management. This review aims to present effectors in their roles as promotors of health or disease for the plant host.
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Affiliation(s)
- Jewel Nicole Anna Todd
- Unidad de Biotecnología, Centro de Investigación Científica de Yucatán, A.C., Calle 43 No. 130 x 32 y 34, Colonia Chuburná de Hidalgo, Mérida C.P. 97205, Yucatán, Mexico
| | - Karla Gisel Carreón-Anguiano
- Unidad de Biotecnología, Centro de Investigación Científica de Yucatán, A.C., Calle 43 No. 130 x 32 y 34, Colonia Chuburná de Hidalgo, Mérida C.P. 97205, Yucatán, Mexico
| | - Ignacio Islas-Flores
- Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de Yucatán, A.C., Calle 43 No. 130 x 32 y 34, Colonia Chuburná de Hidalgo, Mérida C.P. 97205, Yucatán, Mexico
| | - Blondy Canto-Canché
- Unidad de Biotecnología, Centro de Investigación Científica de Yucatán, A.C., Calle 43 No. 130 x 32 y 34, Colonia Chuburná de Hidalgo, Mérida C.P. 97205, Yucatán, Mexico
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6
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Hu L, Lin B, Chen J, Song H, Zhuo K, Liao J. The effector MJ-10A08 of Meloidogyne javanica is required for parasitism that suppressed programmed cell death in Nicotiana benthamiana. NEMATOLOGY 2022. [DOI: 10.1163/15685411-bja10182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Summary
Effectors synthesised in the pharyngeal glands are important in the successful invasion of root-knot nematodes. Meloidogyne javanica is among the nematodes that cause the most damage to various crops. In this study, an effector named MJ-10A08 of M. javanica was identified and investigated. Mj-10A08 was exclusively expressed in the dorsal pharyngeal gland cell and highly expressed in the parasitic second-juvenile stage of M. javanica. Transgenic tobaccos that over-expressed Mj-10A08 were more susceptible to M. javanica; however, host delivered RNAi of Mj-10A08 in tobacco significantly decreased the expression level of Mj-10A08 and the infection efficiency of M. javanica. Transient expression in tobacco leaves demonstrated that MJ-10A08 suppressed programmed cell death caused by BAX and Gpa2/RBP-1. Our results indicated that MJ-10A08 is implicated in the suppression of plant defence response during nematode infection and plays an important role in the parasitism of M. javanica.
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Affiliation(s)
- Lili Hu
- Guangdong Provincial Key Laboratory of Silviculture, Protection and Utilization, Guangdong Academy of Forestry, Guangzhou 510520, P.R. China
- Laboratory of Plant Nematology, South China Agricultural University, Guangzhou 510642, P.R. China
| | - Borong Lin
- Laboratory of Plant Nematology, South China Agricultural University, Guangzhou 510642, P.R. China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, P.R. China
| | - Jiansong Chen
- Laboratory of Plant Nematology, South China Agricultural University, Guangzhou 510642, P.R. China
| | - Handa Song
- Laboratory of Plant Nematology, South China Agricultural University, Guangzhou 510642, P.R. China
| | - Kan Zhuo
- Laboratory of Plant Nematology, South China Agricultural University, Guangzhou 510642, P.R. China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, P.R. China
| | - Jinling Liao
- Laboratory of Plant Nematology, South China Agricultural University, Guangzhou 510642, P.R. China
- Guangdong Eco-Engineering Polytechnic, Guangzhou 510520, P.R. China
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7
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Jeleńska J, Lee J, Manning AJ, Wolfgeher DJ, Ahn Y, Walters-Marrah G, Lopez IE, Garcia L, McClerklin SA, Michelmore RW, Kron SJ, Greenberg JT. Pseudomonas syringae effector HopZ3 suppresses the bacterial AvrPto1-tomato PTO immune complex via acetylation. PLoS Pathog 2021; 17:e1010017. [PMID: 34724007 PMCID: PMC8584673 DOI: 10.1371/journal.ppat.1010017] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 11/11/2021] [Accepted: 10/07/2021] [Indexed: 11/23/2022] Open
Abstract
The plant pathogen Pseudomonas syringae secretes multiple effectors that modulate plant defenses. Some effectors trigger defenses due to specific recognition by plant immune complexes, whereas others can suppress the resulting immune responses. The HopZ3 effector of P. syringae pv. syringae B728a (PsyB728a) is an acetyltransferase that modifies not only components of plant immune complexes, but also the Psy effectors that activate these complexes. In Arabidopsis, HopZ3 acetylates the host RPM1 complex and the Psy effectors AvrRpm1 and AvrB3. This study focuses on the role of HopZ3 during tomato infection. In Psy-resistant tomato, the main immune complex includes PRF and PTO, a RIPK-family kinase that recognizes the AvrPto effector. HopZ3 acts as a virulence factor on tomato by suppressing AvrPto1Psy-triggered immunity. HopZ3 acetylates AvrPto1Psy and the host proteins PTO, SlRIPK and SlRIN4s. Biochemical reconstruction and site-directed mutagenesis experiments suggest that acetylation acts in multiple ways to suppress immune signaling in tomato. First, acetylation disrupts the critical AvrPto1Psy-PTO interaction needed to initiate the immune response. Unmodified residues at the binding interface of both proteins and at other residues needed for binding are acetylated. Second, acetylation occurs at residues important for AvrPto1Psy function but not for binding to PTO. Finally, acetylation reduces specific phosphorylations needed for promoting the immune-inducing activity of HopZ3’s targets such as AvrPto1Psy and PTO. In some cases, acetylation competes with phosphorylation. HopZ3-mediated acetylation suppresses the kinase activity of SlRIPK and the phosphorylation of its SlRIN4 substrate previously implicated in PTO-signaling. Thus, HopZ3 disrupts the functions of multiple immune components and the effectors that trigger them, leading to increased susceptibility to infection. Finally, mass spectrometry used to map specific acetylated residues confirmed HopZ3’s unusual capacity to modify histidine in addition to serine, threonine and lysine residues. By secreting virulence proteins (effectors) into their hosts, pathogenic bacteria hijack host cellular processes to promote bacterial colonization and disease development. For the plant pathogen Pseudomonas syringae, the coordinated action of effectors often mediates modifications of host defense proteins to inhibit their function. However, plants have evolved the ability to induce innate immunity upon recognition of effector-induced modifications of host proteins. How do pathogens circumvent the immune-inducing activity of certain effectors? They deploy more effectors to suppress these defenses. HopZ3, an acetyltransferase from P. syringae, is unique among plant pathogen effectors characterized so far in its ability to modify not only multiple components of the effector-triggered immune pathway, but also the triggering effector itself. Through the direct acetylation of residues involved in the interaction and activation of the bacterial effector AvrPto1Psy and tomato kinase PTO, HopZ3 modifications disrupt their binding and block phosphorylations necessary for immune induction. Additionally, HopZ3 acetylates other possible components in the PTO signaling pathway, including activation sites in SlRIPK kinase, leading to suppression of its activity and reduced phosphorylation of SlRIN4s. Our study emphasizes the importance of HopZ3-dependent acetylation of immune complexes and bacterial effectors across plant species in the suppression of effector-induced immunity.
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Affiliation(s)
- Joanna Jeleńska
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois, United States of America
| | - Jiyoung Lee
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois, United States of America
| | - Andrew J. Manning
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois, United States of America
| | - Donald J. Wolfgeher
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois, United States of America
| | - Youngjoo Ahn
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois, United States of America
| | - George Walters-Marrah
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois, United States of America
| | - Ivan E. Lopez
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois, United States of America
| | - Lissette Garcia
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois, United States of America
| | - Sheri A. McClerklin
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois, United States of America
| | - Richard W. Michelmore
- The Genome Center & Department of Plant Sciences, University of California, Davis, California, United States of America
| | - Stephen J. Kron
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois, United States of America
| | - Jean T. Greenberg
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois, United States of America
- * E-mail:
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8
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Kan CC, Mendoza-Herrera A, Levy J, Hull JJ, Fabrick JA, Tamborindeguy C. HPE1, an Effector from Zebra Chip Pathogen Interacts with Tomato Proteins and Perturbs Ubiquitinated Protein Accumulation. Int J Mol Sci 2021; 22:9003. [PMID: 34445707 PMCID: PMC8396652 DOI: 10.3390/ijms22169003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/10/2021] [Accepted: 08/16/2021] [Indexed: 12/20/2022] Open
Abstract
The gram-negative bacterial genus Liberibacter includes economically important pathogens, such as 'Candidatus Liberibacter asiaticus' that cause citrus greening disease (or Huanglongbing, HLB) and 'Ca. Liberibacter solanacearum' (Lso) that cause zebra chip disease in potato. Liberibacter pathogens are fastidious bacteria transmitted by psyllids. Pathogen manipulation of the host' and vector's immune system for successful colonization is hypothesized to be achieved by Sec translocon-dependent effectors (SDE). In previous work, we identified hypothetical protein effector 1 (HPE1), an SDE from Lso, that acts as a suppressor of the plant's effector-triggered immunity (ETI)-like response. In this study, using a yeast two-hybrid system, we identify binding interactions between tomato RAD23 proteins and HPE1. We further show that HPE1 interacts with RAD23 in both nuclear and cytoplasmic compartments in planta. Immunoblot assays show that HPE1 is not ubiquitinated in the plant cell, but rather the expression of HPE1 induced the accumulation of other ubiquitinated proteins. A similar accumulation of ubiquitinated proteins is also observed in Lso infected tomato plants. Finally, earlier colonization and symptom development following Lso haplotype B infection are observed in HPE1 overexpressing plants compared to wild-type plants. Overall, our results suggest that HPE1 plays a role in virulence in Lso pathogenesis, possibly by perturbing the ubiquitin-proteasome system via direct interaction with the ubiquitin-like domain of RAD23 proteins.
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Affiliation(s)
- Chia-Cheng Kan
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA; (C.-C.K.); (A.M.-H.)
| | - Azucena Mendoza-Herrera
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA; (C.-C.K.); (A.M.-H.)
| | - Julien Levy
- Department of Horticultural Sciences, Texas A&M University, College Station, TX 77843, USA;
| | - J. Joe Hull
- USDA-ARS, Arid Land Agricultural Research Center, Maricopa, AZ 85138, USA; (J.J.H.); (J.A.F.)
| | - Jeffery A. Fabrick
- USDA-ARS, Arid Land Agricultural Research Center, Maricopa, AZ 85138, USA; (J.J.H.); (J.A.F.)
| | - Cecilia Tamborindeguy
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA; (C.-C.K.); (A.M.-H.)
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9
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Derevnina L, Contreras MP, Adachi H, Upson J, Vergara Cruces A, Xie R, Skłenar J, Menke FLH, Mugford ST, MacLean D, Ma W, Hogenhout SA, Goverse A, Maqbool A, Wu CH, Kamoun S. Plant pathogens convergently evolved to counteract redundant nodes of an NLR immune receptor network. PLoS Biol 2021; 19:e3001136. [PMID: 34424903 PMCID: PMC8412950 DOI: 10.1371/journal.pbio.3001136] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 09/02/2021] [Accepted: 07/27/2021] [Indexed: 12/16/2022] Open
Abstract
In plants, nucleotide-binding domain and leucine-rich repeat (NLR)-containing proteins can form receptor networks to confer hypersensitive cell death and innate immunity. One class of NLRs, known as NLR required for cell death (NRCs), are central nodes in a complex network that protects against multiple pathogens and comprises up to half of the NLRome of solanaceous plants. Given the prevalence of this NLR network, we hypothesised that pathogens convergently evolved to secrete effectors that target NRC activities. To test this, we screened a library of 165 bacterial, oomycete, nematode, and aphid effectors for their capacity to suppress the cell death response triggered by the NRC-dependent disease resistance proteins Prf and Rpi-blb2. Among 5 of the identified suppressors, 1 cyst nematode protein and 1 oomycete protein suppress the activity of autoimmune mutants of NRC2 and NRC3, but not NRC4, indicating that they specifically counteract a subset of NRC proteins independently of their sensor NLR partners. Whereas the cyst nematode effector SPRYSEC15 binds the nucleotide-binding domain of NRC2 and NRC3, the oomycete effector AVRcap1b suppresses the response of these NRCs via the membrane trafficking-associated protein NbTOL9a (Target of Myb 1-like protein 9a). We conclude that plant pathogens have evolved to counteract central nodes of the NRC immune receptor network through different mechanisms. Coevolution with pathogen effectors may have driven NRC diversification into functionally redundant nodes in a massively expanded NLR network.
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Affiliation(s)
- Lida Derevnina
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
| | | | - Hiroaki Adachi
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
| | - Jessica Upson
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
| | - Angel Vergara Cruces
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
- Department of Biology, Swiss Federal Institute of Technology (ETH), Zürich, Switzerland
| | - Rongrong Xie
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
- Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai, Jiao Tong University, Shanghai, China
| | - Jan Skłenar
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
| | - Frank L. H. Menke
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
| | - Sam T. Mugford
- Department of Crop Genetics, John Innes Centre, Norwich, United Kingdom
| | - Dan MacLean
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
| | - Wenbo Ma
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
- Department of Plant Pathology and Microbiology, University of California, Riverside, California, United States of America
| | | | - Aska Goverse
- Laboratory of Nematology, Wageningen University and Research, Wageningen, the Netherlands
| | - Abbas Maqbool
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
| | - Chih-Hang Wu
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Sophien Kamoun
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
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10
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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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11
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Montenegro Alonso AP, Ali S, Song X, Linning R, Bakkeren G. UhAVR1, an HR-Triggering Avirulence Effector of Ustilago hordei, Is Secreted via the ER-Golgi Pathway, Localizes to the Cytosol of Barley Cells during in Planta-Expression, and Contributes to Virulence Early in Infection. J Fungi (Basel) 2020; 6:E178. [PMID: 32961976 PMCID: PMC7559581 DOI: 10.3390/jof6030178] [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: 08/15/2020] [Revised: 09/15/2020] [Accepted: 09/15/2020] [Indexed: 12/19/2022] Open
Abstract
The basidiomycete Ustilago hordei causes covered smut disease of barley and oats. Virulence effectors promoting infection and supporting pathogen lifestyle have been described for this fungus. Genetically, six avirulence genes are known and one codes for UhAVR1, the only proven avirulence effector identified in smuts to date that triggers complete immunity in barley cultivars carrying resistance gene Ruh1. A prerequisite for resistance breeding is understanding the host targets and molecular function of UhAVR1. Analysis of this effector upon natural infection of barley coleoptiles using teliospores showed that UhAVR1 is expressed during the early stages of fungal infection where it leads to HR triggering in resistant cultivars or performs its virulence function in susceptible cultivars. Fungal secretion of UhAVR1 is directed by its signal peptide and occurs via the BrefeldinA-sensitive ER-Golgi pathway in cell culture away from its host. Transient in planta expression of UhAVR1 in barley and a nonhost, Nicotiana benthamiana, supports a cytosolic localization. Delivery of UhAVR1 via foxtail mosaic virus or Pseudomonas species in both barley and N. benthamiana reveals a role in suppressing components common to both plant systems of Effector- and Pattern-Triggered Immunity, including necrosis triggered by Agrobacterium-delivered cell death inducers.
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Affiliation(s)
- Ana Priscilla Montenegro Alonso
- Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada;
- Agriculture and Agri-Food Canada, Summerland Research and Development Centre, Summerland, BC V0H 1Z0, Canada;
| | - Shawkat Ali
- Agriculture and Agri-Food Canada, Kentville Research and Development Centre, Kentville, NS B4N 1J5, Canada;
| | - Xiao Song
- Sandstone Pharmacies Glenmore Landing Calgary-Compounding, 167D, 1600–90 Ave SW Calgary, AB T2V 5A8, Canada;
| | - Rob Linning
- Agriculture and Agri-Food Canada, Summerland Research and Development Centre, Summerland, BC V0H 1Z0, Canada;
| | - Guus Bakkeren
- Agriculture and Agri-Food Canada, Summerland Research and Development Centre, Summerland, BC V0H 1Z0, Canada;
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12
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Wang J, Yeckel G, Kandoth PK, Wasala L, Hussey RS, Davis EL, Baum TJ, Mitchum MG. Targeted suppression of soybean BAG6-induced cell death in yeast by soybean cyst nematode effectors. MOLECULAR PLANT PATHOLOGY 2020; 21:1227-1239. [PMID: 32686295 PMCID: PMC7411569 DOI: 10.1111/mpp.12970] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 06/10/2020] [Accepted: 06/11/2020] [Indexed: 05/29/2023]
Abstract
While numerous effectors that suppress plant immunity have been identified from bacteria, fungi, and oomycete pathogens, relatively little is known for nematode effectors. Several dozen effectors have been reported from the soybean cyst nematode (SCN). Previous studies suggest that a hypersensitive response-like programmed cell death is triggered at nematode feeding sites in soybean during an incompatible interaction. However, virulent SCN populations overcome this incompatibility using unknown mechanisms. A soybean BAG6 (Bcl-2 associated anthanogene 6) gene previously reported by us to be highly up-regulated in degenerating feeding sites induced by SCN in a resistant soybean line was attenuated in response to a virulent SCN population. We show that GmBAG6-1 induces cell death in yeast like its Arabidopsis homolog AtBAG6 and also in soybean. This led us to hypothesize that virulent SCN may target GmBAG6-1 as part of their strategy to overcome soybean defence responses during infection. Thus, we used a yeast viability assay to screen SCN effector candidates for their ability to specifically suppress GmBAG6-1-induced cell death. We identified several effectors that strongly suppressed cell death mediated by GmBAG6-1. Two effectors identified as suppressors showed direct interaction with GmBAG6-1 in yeast, suggesting that one mechanism of cell death suppression may occur through an interaction with this host protein.
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Affiliation(s)
- Jianying Wang
- Division of Plant Sciences and Bond Life Sciences CenterUniversity of MissouriColumbiaMOUSA
| | - Greg Yeckel
- Division of Plant Sciences and Bond Life Sciences CenterUniversity of MissouriColumbiaMOUSA
- Present address:
Corteva AgriscienceJohnstonIAUSA
| | - Pramod K. Kandoth
- Division of Plant Sciences and Bond Life Sciences CenterUniversity of MissouriColumbiaMOUSA
- Present address:
National Agri‐food Biotechnology InstituteMohaliIndia
| | - Lakmini Wasala
- Division of Plant Sciences and Bond Life Sciences CenterUniversity of MissouriColumbiaMOUSA
- Present address:
Department of Veterinary PathobiologyUniversity of MissouriColumbiaMOUSA
| | | | - Eric L. Davis
- Department of Entomology and Plant PathologyNorth Carolina State UniversityRaleighNCUSA
| | - Thomas J. Baum
- Department of Plant Pathology and MicrobiologyIowa State UniversityAmesIAUSA
| | - Melissa G. Mitchum
- Division of Plant Sciences and Bond Life Sciences CenterUniversity of MissouriColumbiaMOUSA
- Department of Plant Pathology and Institute of Plant Breeding, Genetics, and GenomicsUniversity of GeorgiaAthensGAUSA
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13
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Roberts R, Liu AE, Wan L, Geiger AM, Hind SR, Rosli HG, Martin GB. Molecular Characterization of Differences between the Tomato Immune Receptors Flagellin Sensing 3 and Flagellin Sensing 2. PLANT PHYSIOLOGY 2020; 183:1825-1837. [PMID: 32503903 PMCID: PMC7401135 DOI: 10.1104/pp.20.00184] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 06/01/2020] [Indexed: 05/05/2023]
Abstract
Plants mount defense responses by recognizing indicators of pathogen invasion, including microbe-associated molecular patterns (MAMPs). Flagellin, from the bacterial pathogen Pseudomonas syringae pv. tomato (Pst), contains two MAMPs, flg22 and flgII-28, that are recognized by tomato (Solanum lycopersicum) receptors Flagellin sensing2 (Fls2) and Fls3, respectively, but to what degree each receptor contributes to immunity and whether they promote immune responses using the same molecular mechanisms are unknown. Here, we characterized CRISPR/Cas9-generated Fls2 and Fls3 tomato mutants and found that the two receptors contribute equally to disease resistance both on the leaf surface and in the apoplast. However, we observed striking differences in certain host responses mediated by the two receptors. Compared to Fls2, Fls3 mediated a more sustained production of reactive oxygen species and an increase in transcript abundance of 44 tomato genes, with two genes serving as specific reporters for the Fls3 pathway. Fls3 had greater in vitro kinase activity than Fls2 and could transphosphorylate a substrate. Using chimeric Fls2/Fls3 proteins, we found no evidence that a single receptor domain is responsible for the Fls3-sustained reactive oxygen species, suggesting involvement of multiple structural features or a nullified function of the chimeric construct. This work reveals differences in certain immunity outputs between Fls2 and Fls3, suggesting that they might use distinct molecular mechanisms to activate pattern-triggered immunity in response to flagellin-derived MAMPs.
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Affiliation(s)
- Robyn Roberts
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853
| | - Alexander E Liu
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853
| | - Lingwei Wan
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853
| | - Annie M Geiger
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853
| | - Sarah R Hind
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853
| | - Hernan G Rosli
- Instituto de Fisiología Vegetal, Universidad Nacional de La Plata, Consejo Nacional de Investigaciones Científicas y Técnicas, La Plata, Buenos Aires, Argentina
| | - Gregory B Martin
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853
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14
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Aljbory Z, Aikins MJ, Park Y, Reeck GR, Chen M. Differential localization of Hessian fly candidate effectors in resistant and susceptible wheat plants. PLANT DIRECT 2020; 4:e00246. [PMID: 32818166 PMCID: PMC7428492 DOI: 10.1002/pld3.246] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 06/28/2020] [Accepted: 07/03/2020] [Indexed: 06/01/2023]
Abstract
Hessian fly Mayetiola destructor is a notorious pest of wheat. Previous studies suggest that Hessian fly uses effector-based mechanisms to attack wheat plants during parasitism, but no direct evidence has been reported to support this postulation. Here, we produced recombinant proteins for five Family-1 candidate effectors and antibodies. Indirect immunostaining and western blots were carried out to examine the localization of Hessian fly Family-1 proteins in plant and insect tissues. Confocal images revealed that Family-1 putative effectors were exclusively produced in the basal region of larval salivary glands, which are directly linked to the mandibles' ducts for effector injection. The five Family-1 proteins were detected in infested host plants on western blots. Indirect immunostaining of sectioned host tissues around the feeding site revealed strikingly different localization patterns between resistant and susceptible plants. In susceptible plants, the Family-1 proteins penetrated from the feeding cell into deep tissues, indicative of movement between cells during nutritive cell formation. In contrast, the Hessian fly proteins were primarily limited to the initially attacked cells in resistant plants. The limitation of effectors' spread in resistant plants was likely due to wall strengthening and rapid hypersensitive cell death. Cell death was found in Nicotiana benthamiana in association with hypersensitive reaction triggered by the Family-1 effector SSGP-1A2. Our finding represents a significant progress in visualizing insect effectors in host tissues and mechanisms of plant resistance and susceptibility to gall midge pests.
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Affiliation(s)
- Zainab Aljbory
- Department of EntomologyKansas State UniversityManhattanKSUSA
- College of AgricultureGreen University of Al QasimIraq
| | | | - Yoonseong Park
- Department of EntomologyKansas State UniversityManhattanKSUSA
| | - Gerald R. Reeck
- Department of Biochemistry and Molecular BiophysicsKansas State UniversityManhattanKSUSA
| | - Ming‐Shun Chen
- Department of EntomologyKansas State UniversityManhattanKSUSA
- Hard Winter Wheat Genetics Research UnitUSDA‐ARSKansas State UniversityManhattanKSUSA
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15
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Zhang Q, Zhang X, Zhuang R, Wei Z, Shu W, Wang X, Kang Z. TaRac6 Is a Potential Susceptibility Factor by Regulating the ROS Burst Negatively in the Wheat- Puccinia striiformis f. sp. tritici Interaction. FRONTIERS IN PLANT SCIENCE 2020; 11:716. [PMID: 32695124 PMCID: PMC7338558 DOI: 10.3389/fpls.2020.00716] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 05/06/2020] [Indexed: 05/30/2023]
Abstract
Rac/Rop proteins play important roles in the regulation of cell growth and plant defense responses. However, the function of Rac/Rop proteins in wheat remains largely unknown. In this study, a small G protein gene, designated as TaRac6, was characterized from wheat (Triticum aestivum) in response to Puccinia striiformis f. sp. tritici (Pst) and was found to be highly homologous to the Rac proteins identified in other plant species. Transient expression analyses of the TaRac6-GFP fusion protein in Nicotiana benthamiana leaves showed that TaRac6 was localized in the whole cell. Furthermore, transient expression of TaRac6 inhibited Bax-triggered plant cell death (PCD) in N. benthamiana. Transcript accumulation of TaRac6 was increased at 24 h post-inoculation (hpi) in the compatible interaction between wheat and Pst, while it was not induced in an incompatible interaction. More importantly, silencing of TaRac6 by virus induced gene silencing (VIGS) enhanced the resistance of wheat (Suwon 11) to Pst (CYR31) by producing fewer uredinia. Histological observations revealed that the hypha growth of Pst was markedly inhibited along with more H2O2 generated in the TaRac6-silenced leaves in response to Pst. Moreover, transcript levels of TaCAT were significantly down-regulated, while those of TaSOD and TaNOX were significantly up-regulated. These results suggest that TaRac6 functions as a potential susceptibility factor, which negatively regulate the reactive oxygen species (ROS) burst in the wheat-Pst interaction.
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Affiliation(s)
- Qiong Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, China
| | - Xinmei Zhang
- College of Life Sciences, Northwest A&F University, Yangling, China
| | - Rui Zhuang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, China
| | - Zetong Wei
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, China
| | - Weixue Shu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, China
| | - Xiaojie Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, China
| | - Zhensheng Kang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, China
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16
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Huang K, Jiang Q, Liu L, Zhang S, Liu C, Chen H, Ding W, Zhang Y. Exploring the key microbial changes in the rhizosphere that affect the occurrence of tobacco root-knot nematodes. AMB Express 2020; 10:72. [PMID: 32297018 PMCID: PMC7158972 DOI: 10.1186/s13568-020-01006-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 04/07/2020] [Indexed: 12/31/2022] Open
Abstract
Root-knot nematode (RKN) disease is a soil-borne disease. However, most studies on RKN have focused on the screening of agents and the cultivation of resistant varieties, and reports on the interaction of RKNs with soil microorganisms are few. In this study, we performed Illumina high-throughput sequencing to analyze diseased and healthy soil and the microbial-community changes in rhizosphere soil after microbial treatment (Pseudomonas flurescens, Bacillus subtilis, Paecolomyces lilacinus). Results showed significant differences in the bacterial community richness and diversity between diseased and healthy soil and the presence of different microbial species. After treatment, the richness and diversity of microbial communities in soil, as well as the number and incidence of second-stage juvenile of RKNs, decreased. Through linear discriminant analysis effect size, Pearson correlation, and Venn diagram analysis, we screened five genera that were closely related to disease occurrence, among which Pseudomonas was most related to disease inhibition. Our results suggested that the occurrence of tobacco RKN was related to changes in soil microbial communities, and that the interactions among Pseudomonas, Bryobacter, Variibacter, Coniochaeta, and Metarhizium affected the health of rhizosphere soil.
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17
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Kim JH, Castroverde CDM. Diversity, Function and Regulation of Cell Surface and Intracellular Immune Receptors in Solanaceae. PLANTS 2020; 9:plants9040434. [PMID: 32244634 PMCID: PMC7238418 DOI: 10.3390/plants9040434] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 03/14/2020] [Accepted: 03/23/2020] [Indexed: 12/29/2022]
Abstract
The first layer of the plant immune system comprises plasma membrane-localized receptor proteins and intracellular receptors of the nucleotide-binding leucine-rich repeat protein superfamily. Together, these immune receptors act as a network of surveillance machines in recognizing extracellular and intracellular pathogen invasion-derived molecules, ranging from conserved structural epitopes to virulence-promoting effectors. Successful pathogen recognition leads to physiological and molecular changes in the host plants, which are critical for counteracting and defending against biotic attack. A breadth of significant insights and conceptual advances have been derived from decades of research in various model plant species regarding the structural complexity, functional diversity, and regulatory mechanisms of these plant immune receptors. In this article, we review the current state-of-the-art of how these host surveillance proteins function and how they are regulated. We will focus on the latest progress made in plant species belonging to the Solanaceae family, because of their tremendous importance as model organisms and agriculturally valuable crops.
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Affiliation(s)
- Jong Hum Kim
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
- Howard Hughes Medical Institute, Michigan State University, East Lansing, MI 48824, USA
- Correspondence: (J.H.K.); (C.D.M.C.)
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18
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Isolation, Characterisation and Experimental Evolution of Phage that Infect the Horse Chestnut Tree Pathogen, Pseudomonas syringae pv. aesculi. Curr Microbiol 2020; 77:1438-1447. [PMID: 32193605 PMCID: PMC7334240 DOI: 10.1007/s00284-020-01952-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 03/11/2020] [Indexed: 11/13/2022]
Abstract
Bleeding canker of horse chestnut trees is a bacterial disease, caused by the bacterium Pseudomonas syringae pv. aesculi, estimated to be present in ~ 50% of UK horse chestnut trees. Currently, the disease has no cure and tree removal can be a common method of reducing inoculum and preventing spread. One potential method of control could be achieved using naturally occurring bacteriophages infective to the causative bacterium. Bacteriophages were isolated from symptomatic and asymptomatic horse chestnut trees in three locations in the South East of England. The phages were found to be belonging to both the Myoviridae and Podoviridae families by RAPD PCR and transmission electron microscopy. Experimental coevolution was carried out to understand the dynamics of bacterial resistance and phage infection and to determine whether new infective phage genotypes would emerge. The phages exhibited different coevolution patterns with their bacterial hosts across time. This approach could be used to generate novel phages for use in biocontrol cocktails in an effort to reduce the potential emergence of bacterial resistance.
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19
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Collmer A. James Robert Alfano, A Giant in Phytopathogenic Bacteria Effector Biology. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2020; 33:377-381. [PMID: 31990622 DOI: 10.1094/mpmi-12-19-0354-cr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The worldwide molecular plant-microbe interactions research community was significantly diminished in November 2019 by the death of James "Jim" Robert Alfano at age 56. Jim was a giant in our field, who gained key insights into plant pathogenesis using the model bacterial pathogen Pseudomonas syringae. As a mentor, collaborator, and, above all, a friend, I know Jim's many dimensions and accomplishments and, sadly, the depth of loss being felt by the many people around the world who were touched by him. In tracing the path of Jim's career, I will emphasize the historical context and impact of his advances and, finally, the essence of the person we will so miss.
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Affiliation(s)
- Alan Collmer
- School of Integrative Plant Science, Section of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, NY 14853, U.S.A
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20
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Xu Q, Tang C, Wang L, Zhao C, Kang Z, Wang X. Haustoria - arsenals during the interaction between wheat and Puccinia striiformis f. sp. tritici. MOLECULAR PLANT PATHOLOGY 2020; 21:83-94. [PMID: 31774224 PMCID: PMC6913192 DOI: 10.1111/mpp.12882] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
As an obligate parasite, Puccinia striiformis f. sp. tritici (Pst) forms haustoria to obtain nutrients from plant cells for development, and these structures are essential for pathogen survival. To better understand the contribution of haustoria to the interactions with the host plants, we isolated haustoria from susceptible wheat leaves infected with Pst race CYR31 and sequenced their transcriptome as well as those of urediospores and germ tubes, and compared the three transcriptomes. A total of 3524 up-regulated genes were obtained from haustoria, of which 73 genes were related to thiamine biosynthesis, glycolysis and lipid metabolic processes. Silencing seven of the genes reduced the growth and development of Pst in wheat. More interestingly, 1197 haustorial secreted proteins (HASPs) were detected in haustoria, accounting for 34% of the total proteins, indicating that these HASPs play important roles in haustorium-mediated pathogenic progression. Furthermore, 69 HASPs were able to suppress Bax-triggered programmed cell death in tobacco. Additionally, 46 HASPs significantly reduced callose deposition in wheat using the type III secretion system. This study identified a large number of effectors through transcriptome sequencing, and the results revealed components of metabolic pathways that impact the growth and colonization of the pathogen and indicate essential functions of haustoria in the growth and pathogenicity of Pst.
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Affiliation(s)
- Qiang Xu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxi712100China
| | - Chunlei Tang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxi712100China
| | - Likun Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxi712100China
| | - Congcong Zhao
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxi712100China
| | - Zhensheng Kang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxi712100China
| | - Xiaojie Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxi712100China
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21
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Cao FY, Khan M, Taniguchi M, Mirmiran A, Moeder W, Lumba S, Yoshioka K, Desveaux D. A host-pathogen interactome uncovers phytopathogenic strategies to manipulate plant ABA responses. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 100:187-198. [PMID: 31148337 DOI: 10.1111/tpj.14425] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 04/05/2018] [Accepted: 05/22/2019] [Indexed: 05/21/2023]
Abstract
The phytopathogen Pseudomonas syringae delivers into host cells type III secreted effectors (T3SEs) that promote virulence. One virulence mechanism employed by T3SEs is to target hormone signaling pathways to perturb hormone homeostasis. The phytohormone abscisic acid (ABA) influences interactions between various phytopathogens and their plant hosts, and has been shown to be a target of P. syringae T3SEs. In order to provide insight into how T3SEs manipulate ABA responses, we generated an ABA-T3SE interactome network (ATIN) between P. syringae T3SEs and Arabidopsis proteins encoded by ABA-regulated genes. ATIN consists of 476 yeast-two-hybrid interactions between 97 Arabidopsis ABA-regulated proteins and 56 T3SEs from four pathovars of P. syringae. We demonstrate that T3SE interacting proteins are significantly enriched for proteins associated with transcription. In particular, the ETHYLENE RESPONSIVE FACTOR (ERF) family of transcription factors is highly represented. We show that ERF105 and ERF8 displayed a role in defense against P. syringae, supporting our overall observation that T3SEs of ATIN converge on proteins that influence plant immunity. In addition, we demonstrate that T3SEs that interact with a large number of ABA-regulated proteins can influence ABA responses. One of these T3SEs, HopF3Pph6 , inhibits the function of ERF8, which influences both ABA-responses and plant immunity. These results provide a potential mechanism for how HopF3Pph6 manipulates ABA-responses to promote P. syringae virulence, and also demonstrate the utility of ATIN as a resource to study the ABA-T3SE interface.
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Affiliation(s)
- Feng Y Cao
- Department of Cell & Systems Biology, University of Toronto, 25 Willcocks St, Toronto, Ontario, M5S 3B2, Canada
| | - Madiha Khan
- Department of Cell & Systems Biology, University of Toronto, 25 Willcocks St, Toronto, Ontario, M5S 3B2, Canada
| | - Masatoshi Taniguchi
- Department of Cell & Systems Biology, University of Toronto, 25 Willcocks St, Toronto, Ontario, M5S 3B2, Canada
| | - Armand Mirmiran
- Department of Cell & Systems Biology, University of Toronto, 25 Willcocks St, Toronto, Ontario, M5S 3B2, Canada
| | - Wolfgang Moeder
- Department of Cell & Systems Biology, University of Toronto, 25 Willcocks St, Toronto, Ontario, M5S 3B2, Canada
| | - Shelley Lumba
- Department of Cell & Systems Biology, University of Toronto, 25 Willcocks St, Toronto, Ontario, M5S 3B2, Canada
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario, Canada
| | - Keiko Yoshioka
- Department of Cell & Systems Biology, University of Toronto, 25 Willcocks St, Toronto, Ontario, M5S 3B2, Canada
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario, Canada
| | - Darrell Desveaux
- Department of Cell & Systems Biology, University of Toronto, 25 Willcocks St, Toronto, Ontario, M5S 3B2, Canada
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario, Canada
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22
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Roberts R, Mainiero S, Powell AF, Liu AE, Shi K, Hind SR, Strickler SR, Collmer A, Martin GB. Natural variation for unusual host responses and flagellin-mediated immunity against Pseudomonas syringae in genetically diverse tomato accessions. THE NEW PHYTOLOGIST 2019; 223:447-461. [PMID: 30861136 DOI: 10.1111/nph.15788] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 03/06/2019] [Indexed: 05/20/2023]
Abstract
The interaction between tomato and Pseudomonas syringae pv tomato (Pst) is a well-developed model for investigating the molecular basis of the plant immune system. There is extensive natural variation in Solanum lycopersicum (tomato) but it has not been fully leveraged to enhance our understanding of the tomato-Pst pathosystem. We screened 216 genetically diverse accessions of cultivated tomato and a wild tomato species for natural variation in their response to three strains of Pst. The host response to Pst was investigated using multiple Pst strains, tomato accessions with available genome sequences, reactive oxygen species (ROS) assays, reporter genes and bacterial population measurements. The screen uncovered a broad range of previously unseen host symptoms in response to Pst, and one of these, stem galls, was found to be simply inherited. The screen also identified tomato accessions that showed enhanced responses to flagellin in bacterial population assays and in ROS assays upon exposure to flagellin-derived peptides, flg22 and flgII-28. Reporter genes confirmed that the host responses were due primarily to pattern recognition receptor-triggered immunity. This study revealed extensive natural variation in tomato for susceptibility and resistance to Pst and will enable elucidation of the molecular mechanisms underlying these host responses.
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Affiliation(s)
- Robyn Roberts
- Boyce Thompson Institute for Plant Research, Ithaca, NY, 14853, USA
| | | | - Adrian F Powell
- Boyce Thompson Institute for Plant Research, Ithaca, NY, 14853, USA
| | - Alexander E Liu
- Boyce Thompson Institute for Plant Research, Ithaca, NY, 14853, USA
| | - Kai Shi
- Boyce Thompson Institute for Plant Research, Ithaca, NY, 14853, USA
- Department of Horticulture, Zhejiang University, Hangzhou, 310058, China
| | - Sarah R Hind
- Boyce Thompson Institute for Plant Research, Ithaca, NY, 14853, USA
| | | | - Alan Collmer
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
| | - Gregory B Martin
- Boyce Thompson Institute for Plant Research, Ithaca, NY, 14853, USA
- Department of Horticultural Biotechnology, College of Life Sciences, Kyung Hee University, Yongin, 17104, Korea
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
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23
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Hao G, McCormick S, Vaughan MM, Naumann TA, Kim HS, Proctor R, Kelly A, Ward TJ. Fusarium graminearum arabinanase (Arb93B) Enhances Wheat Head Blight Susceptibility by Suppressing Plant Immunity. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2019; 32:888-898. [PMID: 30759350 DOI: 10.1094/mpmi-06-18-0170-r] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Fusarium head blight (FHB) of wheat and barley caused by the fungus Fusarium graminearum reduces crop yield and contaminates grain with mycotoxins. In this study, we investigated two exo-1,5-α-L-arabinanases (Arb93A and Arb93B) secreted by F. graminearum and their effect on wheat head blight development. Arabinan is an important component of plant cell walls but it was not known whether these arabinanases play a role in FHB. Both ARB93A and ARB93B were induced during the early stages of infection. arb93A mutants did not exhibit a detectable change in ability to cause FHB, whereas arb93B mutants caused lower levels of FHB symptoms and deoxynivalenol contamination compared with the wild type. Furthermore, virulence and deoxynivalenol contamination were restored to wild-type levels in ARB93B complemented mutants. Fusion proteins of green fluorescent protein (GFP) with the predicted chloroplast peptide or the mature protein of Arb93B were not observed in the chloroplast. Reactive oxygen species (ROS) production was reduced in the infiltrated zones of Nicotiana benthamiana leaves expressing ARB93B-GFP. Coexpression of ARB93B-GFP and Bax in N. benthamiana leaves significantly suppressed Bax-programmed cell death. Our results indicate that Arb93B enhances plant disease susceptibility by suppressing ROS-associated plant defense responses.
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Affiliation(s)
- Guixia Hao
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture-Agricultural Research Service, Peoria, IL, U.S.A
| | - Susan McCormick
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture-Agricultural Research Service, Peoria, IL, U.S.A
| | - Martha M Vaughan
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture-Agricultural Research Service, Peoria, IL, U.S.A
| | - Todd A Naumann
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture-Agricultural Research Service, Peoria, IL, U.S.A
| | - Hye-Seon Kim
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture-Agricultural Research Service, Peoria, IL, U.S.A
| | - Robert Proctor
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture-Agricultural Research Service, Peoria, IL, U.S.A
| | - Amy Kelly
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture-Agricultural Research Service, Peoria, IL, U.S.A
| | - Todd J Ward
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture-Agricultural Research Service, Peoria, IL, U.S.A
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24
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Lammertz M, Kuhn H, Pfeilmeier S, Malone J, Zipfel C, Kwaaitaal M, Lin NC, Kvitko BH, Panstruga R. Widely Conserved Attenuation of Plant MAMP-Induced Calcium Influx by Bacteria Depends on Multiple Virulence Factors and May Involve Desensitization of Host Pattern Recognition Receptors. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2019; 32:608-621. [PMID: 30664393 DOI: 10.1094/mpmi-10-18-0291-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Successful pathogens must efficiently defeat or delay host immune responses, including those triggered by release or exposure of microbe-associated molecular patterns (MAMPs). Knowledge of the molecular details leading to this phenomenon in genuine plant-pathogen interactions is still scarce. We took advantage of the well-established Arabidopsis thaliana-Pseudomonas syringae pv. tomato DC3000 pathosystem to explore the molecular prerequisites for the suppression of MAMP-triggered host defense by the bacterial invader. Using a transgenic Arabidopsis line expressing the calcium sensor apoaequorin, we discovered that strain DC3000 colonization results in a complete inhibition of MAMP-induced cytosolic calcium influx, a key event of immediate-early host immune signaling. A range of further plant-associated bacterial species is also able to prevent, either partially or fully, the MAMP-triggered cytosolic calcium pattern. Genetic analysis revealed that this suppressive effect partially relies on the bacterial type III secretion system (T3SS) but cannot be attributed to individual members of the currently known arsenal of strain DC3000 effector proteins. Although the phytotoxin coronatine and bacterial flagellin individually are dispensable for the effective inhibition of MAMP-induced calcium signatures, they contribute to the attenuation of calcium influx in the absence of the T3SS. Our findings suggest that the capacity to interfere with early plant immune responses is a widespread ability among plant-associated bacteria that, at least in strain DC3000, requires the combinatorial effect of multiple virulence determinants. This may also include the desensitization of host pattern recognition receptors by the prolonged exposure to MAMPs during bacterial pathogenesis.
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Affiliation(s)
- Meltem Lammertz
- 1 Unit of Plant Molecular Cell Biology, Institute for Biology I, RWTH Aachen University, 52074 Aachen, Germany
| | - Hannah Kuhn
- 1 Unit of Plant Molecular Cell Biology, Institute for Biology I, RWTH Aachen University, 52074 Aachen, Germany
| | - Sebastian Pfeilmeier
- 2 John Innes Centre, Norwich Research Park, Norwich NR4 7UH, U.K
- 3 The Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, U.K
| | - Jacob Malone
- 2 John Innes Centre, Norwich Research Park, Norwich NR4 7UH, U.K
- 4 University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, U.K
| | - Cyril Zipfel
- 3 The Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, U.K
| | - Mark Kwaaitaal
- 1 Unit of Plant Molecular Cell Biology, Institute for Biology I, RWTH Aachen University, 52074 Aachen, Germany
| | - Nai-Chun Lin
- 5 Department of Agricultural Chemistry, National Taiwan University, Taipei 106, Taiwan, Republic of China; and
| | - Brian H Kvitko
- 6 Department of Plant Pathology, University of Georgia, Athens, GA 30602, U.S.A
| | - Ralph Panstruga
- 1 Unit of Plant Molecular Cell Biology, Institute for Biology I, RWTH Aachen University, 52074 Aachen, Germany
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25
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Noman A, Aqeel M, Lou Y. PRRs and NB-LRRs: From Signal Perception to Activation of Plant Innate Immunity. Int J Mol Sci 2019; 20:ijms20081882. [PMID: 30995767 PMCID: PMC6514886 DOI: 10.3390/ijms20081882] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 04/02/2019] [Accepted: 04/10/2019] [Indexed: 12/11/2022] Open
Abstract
To ward off pathogens and pests, plants use a sophisticated immune system. They use pattern-recognition receptors (PRRs), as well as nucleotide-binding and leucine-rich repeat (NB-LRR) domains, for detecting nonindigenous molecular signatures from pathogens. Plant PRRs induce local and systemic immunity. Plasma-membrane-localized PRRs are the main components of multiprotein complexes having additional transmembrane and cytosolic kinases. Topical research involving proteins and their interactive partners, along with transcriptional and posttranscriptional regulation, has extended our understanding of R-gene-mediated plant immunity. The unique LRR domain conformation helps in the best utilization of a surface area and essentially mediates protein–protein interactions. Genome-wide analyses of inter- and intraspecies PRRs and NB-LRRs offer innovative information about their working and evolution. We reviewed plant immune responses with relevance to PRRs and NB-LRRs. This article focuses on the significant functional diversity, pathogen-recognition mechanisms, and subcellular compartmentalization of plant PRRs and NB-LRRs. We highlight the potential biotechnological application of PRRs and NB-LRRs to enhance broad-spectrum disease resistance in crops.
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Affiliation(s)
- Ali Noman
- Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310027, China.
- Department of Botany, Government College University, Faisalabad 38000, Pakistan.
| | - Muhammad Aqeel
- State Key Laboratory of Grassland Agro-ecosystems, School of Life Science, Lanzhou University, Lanzhou 730000, China.
| | - Yonggen Lou
- Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310027, China.
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26
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Yang S, Dai Y, Chen Y, Yang J, Yang D, Liu Q, Jian H. A Novel G16B09-Like Effector From Heterodera avenae Suppresses Plant Defenses and Promotes Parasitism. FRONTIERS IN PLANT SCIENCE 2019; 10:66. [PMID: 30800135 PMCID: PMC6376208 DOI: 10.3389/fpls.2019.00066] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 01/16/2019] [Indexed: 05/08/2023]
Abstract
Plant parasitic nematodes secrete effectors into host plant tissues to facilitate parasitism. In this study, we identified a G16B09-like effector protein family from the transcriptome of Heterodera avenae, and then verified that most of the members could suppress programmed cell death triggered by BAX in Nicotiana benthamiana. Ha18764, the most homologous to G16B09, was further characterized for its function. Our experimental evidence suggested that Ha18764 was specifically expressed in the dorsal gland and was dramatically upregulated in the J4 stage of nematode development. A Magnaporthe oryzae secretion system in barley showed that the signal peptide of Ha18764 had secretion activity to deliver mCherry into plant cells. Arabidopsis thaliana overexpressing Ha18764 or Hs18764 was more susceptible to Heterodera schachtii. In contrast, BSMV-based host-induced gene silencing (HIGS) targeting Ha18764 attenuated H. avenae parasitism and its reproduction in wheat plants. Transient expression of Ha18764 suppressed PsojNIP, Avr3a/R3a, RBP-1/Gpa2, and MAPK kinases (MKK1 and NPK1Nt)-related cell death in Nicotiana benthamiana. Co-expression assays indicated that Ha18764 also suppressed cell death triggered by four H. avenae putative cell-death-inducing effectors. Moreover, Ha18764 was also shown strong PTI suppression such as reducing the expression of plant defense-related genes, the burst of reactive oxygen species, and the deposition of cell wall callose. Together, our results indicate that Ha18764 promotes parasitism, probably by suppressing plant PTI and ETI signaling in the parasitic stages of H. avenae.
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Affiliation(s)
| | | | | | | | | | - Qian Liu
- Department of Plant Pathology and MOA Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing, China
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27
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Wang W, Liu N, Gao C, Rui L, Tang D. The Pseudomonas Syringae Effector AvrPtoB Associates With and Ubiquitinates Arabidopsis Exocyst Subunit EXO70B1. FRONTIERS IN PLANT SCIENCE 2019; 10:1027. [PMID: 31555308 PMCID: PMC6726739 DOI: 10.3389/fpls.2019.01027] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 07/23/2019] [Indexed: 05/20/2023]
Abstract
Many bacterial pathogens secret effectors into host cells to disable host defenses and thus promote infection. The exocyst complex functions in the transport and secretion of defense molecules, and loss of function of the EXO70B1 subunit leads to autoimmunity by activation of a truncated Toll/interleukin-1 receptor-nucleotide-binding sequence protein (TIR-NBS2; herein referred to as TN2). Here, we show that EXO70B1 is required for pathogen-associated molecular pattern-triggered immune responses in Arabidopsis thaliana. The effector AvrPtoB, an E3 ligase from Pseudomonas syringae pv. tomato (Pto) strain DC3000, associates with EXO70B1. AvrPtoB ubiquitinates EXO70B1 and mediates EXO70B1 degradation via the host's 26S proteasome in a manner requiring E3 ligase activity. AvrPtoB enhances Pto DC3000 virulence by overcoming EXO70B1-mediated resistance. Moreover, overexpression of AvrPtoB in Arabidopsis leads to autoimmunity, which is partially dependent on TN2. Expression of TN2 in tobacco (Nicotiana tabacum and Nicotiana benthamiana) triggers strong and rapid cell death, which is suppressed by co-expression with EXO70B1 but reoccurs when co-expressed with AvrPtoB. Taken together, our data highlight that AvrPtoB targets the Arabidopsis thaliana EXO70 protein family member EXO70B1 to manipulate the defense molecule secretion machinery or immunity.
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Affiliation(s)
- Wei Wang
- State Key Laboratory of Ecological Control of Fujian-Taiwan Crop Pests, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Plant Immunity Center, Fujian Agriculture and Forestry University, Fuzhou, China
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Na Liu
- State Key Laboratory of Ecological Control of Fujian-Taiwan Crop Pests, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Plant Immunity Center, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Chenyang Gao
- State Key Laboratory of Ecological Control of Fujian-Taiwan Crop Pests, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Plant Immunity Center, Fujian Agriculture and Forestry University, Fuzhou, China
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Lu Rui
- State Key Laboratory of Ecological Control of Fujian-Taiwan Crop Pests, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Plant Immunity Center, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Dingzhong Tang
- State Key Laboratory of Ecological Control of Fujian-Taiwan Crop Pests, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Plant Immunity Center, Fujian Agriculture and Forestry University, Fuzhou, China
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- *Correspondence: Dingzhong Tang,
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28
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Kang WH, Yeom SI. Genome-wide Identification, Classification, and Expression Analysis of the Receptor-Like Protein Family in Tomato. THE PLANT PATHOLOGY JOURNAL 2018; 34:435-444. [PMID: 30369853 PMCID: PMC6200040 DOI: 10.5423/ppj.oa.02.2018.0032] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 05/21/2018] [Accepted: 06/01/2018] [Indexed: 05/20/2023]
Abstract
Receptor-like proteins (RLPs) are involved in plant development and disease resistance. Only some of the RLPs in tomato (Solanum lycopersicum L.) have been functionally characterized though 176 genes encoding RLPs, which have been identified in the tomato genome. To further understand the role of RLPs in tomato, we performed genome-guided classification and transcriptome analysis of these genes. Phylogenic comparisons revealed that the tomato RLP members could be divided into eight subgroups and that the genes evolved independently compared to similar genes in Arabidopsis. Based on location and physical clustering analyses, we conclude that tomato RLPs likely expanded primarily through tandem duplication events. According to tissue specific RNA-seq data, 71 RLPs were expressed in at least one of the following tissues: root, leaf, bud, flower, or fruit. Several genes had expression patterns that were tissue specific. In addition, tomato RLP expression profiles after infection with different pathogens showed distinguish gene regulations according to disease induction and resistance response as well as infection by bacteria and virus. Notably, Some RLPs were highly and/or unique expressed in susceptible tomato to pathogen, suggesting that the RLP could be involved in disease response, possibly as a host-susceptibility factor. Our study could provide an important clues for further investigations into the function of tomato RLPs involved in developmental and response to pathogens.
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Affiliation(s)
- Won-Hee Kang
- Institute of Agriculture & Life Science, Gyeongsang National University, Jinju 52828,
Korea
| | - Seon-In Yeom
- Institute of Agriculture & Life Science, Gyeongsang National University, Jinju 52828,
Korea
- Department of Agricultural Plant Science, Division of Applied Life Science (BK21 Plus program), Gyeongsang National University, Jinju 52828,
Korea
- Corresponding author: Phone) +82-55-772-1917, FAX) +82-55-772-1919, E-mail)
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29
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Wei H, Collmer A. Defining essential processes in plant pathogenesis with Pseudomonas syringae pv. tomato DC3000 disarmed polymutants and a subset of key type III effectors. MOLECULAR PLANT PATHOLOGY 2018; 19:1779-1794. [PMID: 29277959 PMCID: PMC6638048 DOI: 10.1111/mpp.12655] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 11/10/2017] [Accepted: 12/20/2017] [Indexed: 05/22/2023]
Abstract
Pseudomonas syringae pv. tomato DC3000 and its derivatives cause disease in tomato, Arabidopsis and Nicotiana benthamiana. The primary virulence factors include a repertoire of 29 effector proteins injected into plant cells by the type III secretion system and the phytotoxin coronatine. The complete repertoire of effector genes and key coronatine biosynthesis genes have been progressively deleted and minimally reassembled to reconstitute basic pathogenic ability in N. benthamiana, and in Arabidopsis plants that have mutations in target genes that mimic effector actions. This approach and molecular studies of effector activities and plant immune system targets have highlighted a small subset of effectors that contribute to essential processes in pathogenesis. Most notably, HopM1 and AvrE1 redundantly promote an aqueous apoplastic environment, and AvrPtoB and AvrPto redundantly block early immune responses, two conditions that are sufficient for substantial bacterial growth in planta. In addition, disarmed DC3000 polymutants have been used to identify the individual effectors responsible for specific activities of the complete repertoire and to more effectively study effector domains, effector interplay and effector actions on host targets. Such work has revealed that AvrPtoB suppresses cell death elicitation in N. benthamiana that is triggered by another effector in the DC3000 repertoire, highlighting an important aspect of effector interplay in native repertoires. Disarmed DC3000 polymutants support the natural delivery of test effectors and infection readouts that more accurately reveal effector functions in key pathogenesis processes, and enable the identification of effectors with similar activities from a broad range of other pathogens that also defeat plants with cytoplasmic effectors.
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Affiliation(s)
- Hai‐Lei Wei
- School of Integrative Plant ScienceSection of Plant Pathology and Plant–Microbe Biology, Cornell UniversityIthacaNY14853USA
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of AgricultureInstitute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural SciencesBeijing100081China
| | - Alan Collmer
- School of Integrative Plant ScienceSection of Plant Pathology and Plant–Microbe Biology, Cornell UniversityIthacaNY14853USA
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30
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Liang X, Zhou JM. Receptor-Like Cytoplasmic Kinases: Central Players in Plant Receptor Kinase-Mediated Signaling. ANNUAL REVIEW OF PLANT BIOLOGY 2018; 69:267-299. [PMID: 29719165 DOI: 10.1146/annurev-arplant-042817-040540] [Citation(s) in RCA: 242] [Impact Index Per Article: 40.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Receptor kinases (RKs) are of paramount importance in transmembrane signaling that governs plant reproduction, growth, development, and adaptation to diverse environmental conditions. Receptor-like cytoplasmic kinases (RLCKs), which lack extracellular ligand-binding domains, have emerged as a major class of signaling proteins that regulate plant cellular activities in response to biotic/abiotic stresses and endogenous extracellular signaling molecules. By associating with immune RKs, RLCKs regulate multiple downstream signaling nodes to orchestrate a complex array of defense responses against microbial pathogens. RLCKs also associate with RKs that perceive brassinosteroids and signaling peptides to coordinate growth, pollen tube guidance, embryonic and stomatal patterning, floral organ abscission, and abiotic stress responses. The activity and stability of RLCKs are dynamically regulated not only by RKs but also by other RLCK-associated proteins. Analyses of RLCK-associated components and substrates have suggested phosphorylation relays as a major mechanism underlying RK-mediated signaling.
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Affiliation(s)
- Xiangxiu Liang
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Chaoyang District, 100101 Beijing, China;
| | - Jian-Min Zhou
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Chaoyang District, 100101 Beijing, China;
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31
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Tchagang CF, Xu R, Doumbou CL, Tambong JT. Genome analysis of two novel Pseudomonas strains exhibiting differential hypersensitivity reactions on tobacco seedlings reveals differences in nonflagellar T3SS organization and predicted effector proteins. Microbiologyopen 2018; 7:e00553. [PMID: 29464939 PMCID: PMC5911992 DOI: 10.1002/mbo3.553] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 07/17/2017] [Accepted: 07/18/2017] [Indexed: 11/06/2022] Open
Abstract
Multilocus sequence analysis (MLSA) of two new biological control strains (S1E40 and S3E12) of Pseudomonas was performed to assess their taxonomic position relative to close lineages, and comparative genomics employed to investigate whether these strains differ in key genetic features involved in hypersensitivity responses (HRs). Strain S3E12, at high concentration, incites HRs on tobacco and corn plantlets while S1E40 does not. Phylogenies based on individual genes and 16S rRNA-gyrB-rpoB-rpoD concatenated sequence data show strains S1E40 and S3E12 clustering in distinct groups. Strain S3E12 consistently clustered with Pseudomonas marginalis, a bacterium causing soft rots on plant tissues. MLSA data suggest that strains S1E40 and S3E12 are novel genotypes. This is consistent with the data of genome-based DNA-DNA homology values that are below the proposed cutoff species boundary. Comparative genomics analysis of the two strains revealed major differences in the type III secretion systems (T3SS) as well as the predicted T3SS secreted effector proteins (T3Es). One nonflagellar (NF-T3SS) and two flagellar T3SSs (F-T3SS) clusters were identified in both strains. While F-T3SS clusters in both strains were relatively conserved, the NF-T3SS clusters differed in the number of core components present. The predicted T3Es also differed in the type and number of CDSs with both strains having unique predicted protease-related effectors. In addition, the T1SS organization of the S3E12 genome has protein-coding sequences (CDSs) encoding for key factors such as T1SS secreted agglutinin repeats-toxins (a group of cytolysins and cytotoxins), a membrane fusion protein (LapC), a T1SS ATPase of LssB family (LapB), and T1SS-associated transglutaminase-like cysteine proteinase (LapP). In contrast, strain S1E40 has all CDSs for the seven-gene operon (pelA-pelG) required for Pel biosynthesis but not S3E12, suggesting that biofilm formation in these strains is modulated differently. The data presented here provide an insight of the genome organization of these two phytobacterial strains.
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Affiliation(s)
- Caetanie F. Tchagang
- Ottawa Research and Development CentreOttawaONCanada
- Institut des sciences de santé et de la vie Collège La CitéOttawaONCanada
| | - Renlin Xu
- Ottawa Research and Development CentreOttawaONCanada
| | - Cyr Lézin Doumbou
- Institut des sciences de santé et de la vie Collège La CitéOttawaONCanada
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32
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Duan K, Willig CJ, De Tar JR, Spollen WG, Zhang ZJ. Transcriptomic Analysis of Arabidopsis Seedlings in Response to an Agrobacterium-Mediated Transformation Process. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2018; 31:445-459. [PMID: 29171790 DOI: 10.1094/mpmi-10-17-0249-r] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Agrobacterium tumefaciens is a plant pathogen that causes crown gall disease. This pathogen is capable of transferring the T-DNA from its Ti plasmid to the host cell and, then, integrating it into the host genome. To date, this genetic transformation ability has been harnessed as the dominant technology to produce genetically modified plants for both basic research and crop biotechnological applications. However, little is known about the interaction between Agrobacterium tumefaciens and host plants, especially the host responses to Agrobacterium infection and its associated factors. We employed RNA-seq to follow the time course of gene expression in Arabidopsis seedlings infected with either an avirulent or a virulent Agrobacterium strain. Gene Ontology analysis indicated many biological processes were involved in the Agrobacterium-mediated transformation process, including hormone signaling, defense response, cellular biosynthesis, and nucleic acid metabolism. RNAseq and quantitative reverse transcription-polymerase chain reaction results indicated that expression of genes involved in host plant growth and development were repressed but those involved in defense response were induced by Agrobacterium tumefaciens. Further analysis of the responses of transgenic Arabidopsis lines constitutively expressing either the VirE2 or VirE3 protein suggested Vir proteins act to enhance plant defense responses in addition to their known roles facilitating T-DNA transformation.
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Affiliation(s)
- Kaixuan Duan
- 1 Plant Transformation Core Facility, Division of Plant Sciences, University of Missouri, Columbia, MO, U.S.A.; and
| | - Christopher J Willig
- 1 Plant Transformation Core Facility, Division of Plant Sciences, University of Missouri, Columbia, MO, U.S.A.; and
| | - Joann R De Tar
- 1 Plant Transformation Core Facility, Division of Plant Sciences, University of Missouri, Columbia, MO, U.S.A.; and
| | | | - Zhanyuan J Zhang
- 1 Plant Transformation Core Facility, Division of Plant Sciences, University of Missouri, Columbia, MO, U.S.A.; and
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The bacterial type III-secreted protein AvrRps4 is a bipartite effector. PLoS Pathog 2018; 14:e1006984. [PMID: 29601603 PMCID: PMC5895054 DOI: 10.1371/journal.ppat.1006984] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 04/11/2018] [Accepted: 03/20/2018] [Indexed: 11/21/2022] Open
Abstract
Bacterial effector proteins secreted into host plant cells manipulate those cells to the benefit of the pathogen, but effector-triggered immunity (ETI) occurs when effectors are recognized by host resistance proteins. The RPS4/RRS1 pair recognizes the Pseudomonas syringae pv. pisi effector AvrRps4. AvrRps4 is processed in planta into AvrRps4N (133 amino acids), homologous to the N-termini of other effectors including the native P. syringae pv. tomato strain DC3000 effector HopK1, and AvrRps4C (88 amino acids). Previous data suggested that AvrRps4C alone is necessary and sufficient for resistance when overexpressed in heterologous systems. We show that delivering AvrRps4C from DC3000, but not from a DC3000 hopK1- strain, triggers resistance in the Arabidopsis accession Col-0. Delivering AvrRps4C in tandem with AvrRps4N, or as a chimera with HopK1N, fully complements AvrRps4-triggered immunity. AvrRps4N in the absence of AvrRps4C enhances virulence in Col-0. In addition, AvrRps4N triggers a hypersensitive response in lettuce that is attenuated by coexpression of AvrRps4C, further supporting the role of AvrRps4N as a bona fide effector domain. Based on these results we propose that evolutionarily, fusion of AvrRps4C to AvrRps4N may have counteracted recognition of AvrRps4N, and that the plant RPS4/RRS1 resistance gene pair was selected as a countermeasure. We conclude that AvrRps4 represents an unusual chimeric effector, with recognition in Arabidopsis by RPS4/RRS1 requiring the presence of both processed effector moieties. An important component of the plant immune system relies on the detection of pathogen-derived effectors by immune receptors called resistance proteins. Bacterial pathogens inject effectors into the host cell via a dedicated secretion system to suppress defenses and to manipulate the physiology of the host cell to the pathogen's advantage. Usually, a single resistance protein recognizes a single effector, but an increasing number of exceptions and elaborations on this one-to-one relationship are known. The plant Arabidopsis uses a pair of resistance proteins, RRS1 and RPS4, to detect the effector AvrRps4. After injection into the cell, AvrRps4 is cleaved into two protein parts, and it had been assumed that only the C-terminal part needs to be present to trigger RPS4/RRS1. We show here that both AvrRps4 parts are required for triggering resistance in Arabidopsis, and that the N-terminal part, which previously had been assumed to only function in effector secretion into the host cell, in fact on its own has some functions of an effector. This conclusion is supported by the observation that the N-terminal part of AvrRps4 is sufficient to trigger resistance in lettuce. The fusion of the two AvrRps4 parts may have arisen to counteract plant defenses.
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Büttner D. Behind the lines-actions of bacterial type III effector proteins in plant cells. FEMS Microbiol Rev 2018; 40:894-937. [PMID: 28201715 PMCID: PMC5091034 DOI: 10.1093/femsre/fuw026] [Citation(s) in RCA: 181] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 03/31/2016] [Accepted: 07/03/2016] [Indexed: 01/30/2023] Open
Abstract
Pathogenicity of most Gram-negative plant-pathogenic bacteria depends on the type III secretion (T3S) system, which translocates bacterial effector proteins into plant cells. Type III effectors modulate plant cellular pathways to the benefit of the pathogen and promote bacterial multiplication. One major virulence function of type III effectors is the suppression of plant innate immunity, which is triggered upon recognition of pathogen-derived molecular patterns by plant receptor proteins. Type III effectors also interfere with additional plant cellular processes including proteasome-dependent protein degradation, phytohormone signaling, the formation of the cytoskeleton, vesicle transport and gene expression. This review summarizes our current knowledge on the molecular functions of type III effector proteins with known plant target molecules. Furthermore, plant defense strategies for the detection of effector protein activities or effector-triggered alterations in plant targets are discussed.
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Affiliation(s)
- Daniela Büttner
- Genetics Department, Institute of Biology, Martin-Luther University Halle-Wittenberg, Halle (Saale), Germany
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Qi M, Grayczyk JP, Seitz JM, Lee Y, Link TI, Choi D, Pedley KF, Voegele RT, Baum TJ, Whitham SA. Suppression or Activation of Immune Responses by Predicted Secreted Proteins of the Soybean Rust Pathogen Phakopsora pachyrhizi. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2018; 31:163-174. [PMID: 29144203 DOI: 10.1094/mpmi-07-17-0173-fi] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Rust fungi, such as the soybean rust pathogen Phakopsora pachyrhizi, are major threats to crop production. They form specialized haustoria that are hyphal structures intimately associated with host-plant cell membranes. These haustoria have roles in acquiring nutrients and secreting effector proteins that manipulate host immune systems. Functional characterization of effector proteins of rust fungi is important for understanding mechanisms that underlie their virulence and pathogenicity. Hundreds of candidate effector proteins have been predicted for rust pathogens, but it is not clear how to prioritize these effector candidates for further characterization. There is a need for high-throughput approaches for screening effector candidates to obtain experimental evidence for effector-like functions, such as the manipulation of host immune systems. We have focused on identifying effector candidates with immune-related functions in the soybean rust fungus P. pachyrhizi. To facilitate the screening of many P. pachyrhizi effector candidates (named PpECs), we used heterologous expression systems, including the bacterial type III secretion system, Agrobacterium infiltration, a plant virus, and a yeast strain, to establish an experimental pipeline for identifying PpECs with immune-related functions and establishing their subcellular localizations. Several PpECs were identified that could suppress or activate immune responses in nonhost Nicotiana benthamiana, N. tabacum, Arabidopsis, tomato, or pepper plants.
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Affiliation(s)
- Mingsheng Qi
- 1 Department of Plant Pathology and Microbiology, Iowa State University, Ames 50011, U.S.A
| | - James P Grayczyk
- 1 Department of Plant Pathology and Microbiology, Iowa State University, Ames 50011, U.S.A
| | - Janina M Seitz
- 2 Institut für Phytomedizin, Universität Hohenheim, Otto-Sander-Straße 5, 70599 Stuttgart, Germany
| | - Youngsill Lee
- 3 Department of Plant Science, Plant Genomics and Breeding Institute, Seoul National University, Seoul 151-921, Korea; and
| | - Tobias I Link
- 2 Institut für Phytomedizin, Universität Hohenheim, Otto-Sander-Straße 5, 70599 Stuttgart, Germany
| | - Doil Choi
- 3 Department of Plant Science, Plant Genomics and Breeding Institute, Seoul National University, Seoul 151-921, Korea; and
| | - Kerry F Pedley
- 4 Foreign Disease-Weed Science Research Unit, United States Department of Agriculture-Agricultural Research Service, Ft. Detrick, MD 21702, U.S.A
| | - Ralf T Voegele
- 2 Institut für Phytomedizin, Universität Hohenheim, Otto-Sander-Straße 5, 70599 Stuttgart, Germany
| | - Thomas J Baum
- 1 Department of Plant Pathology and Microbiology, Iowa State University, Ames 50011, U.S.A
| | - Steven A Whitham
- 1 Department of Plant Pathology and Microbiology, Iowa State University, Ames 50011, U.S.A
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36
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Zhou B, Zeng L. Conventional and unconventional ubiquitination in plant immunity. MOLECULAR PLANT PATHOLOGY 2017; 18:1313-1330. [PMID: 27925369 PMCID: PMC6638253 DOI: 10.1111/mpp.12521] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 11/23/2016] [Accepted: 11/27/2016] [Indexed: 05/16/2023]
Abstract
Ubiquitination is one of the most abundant types of protein post-translational modification (PTM) in plant cells. The importance of ubiquitination in the regulation of many aspects of plant immunity has been increasingly appreciated in recent years. Most of the studies linking ubiquitination to the plant immune system, however, have been focused on the E3 ubiquitin ligases and the conventional ubiquitination that leads to the degradation of the substrate proteins by the 26S proteasome. By contrast, our knowledge about the role of unconventional ubiquitination that often serves as non-degradative, regulatory signal remains a significant gap. We discuss, in this review, the recent advances in our understanding of ubiquitination in the modulation of plant immunity, with a particular focus on the E3 ubiquitin ligases. We approach the topic from a perspective of two broadly defined types of ubiquitination in an attempt to highlight the importance, yet current scarcity, in our knowledge about the regulation of plant immunity by unconventional ubiquitination.
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Affiliation(s)
- Bangjun Zhou
- Center for Plant Science Innovation and Department of Plant PathologyUniversity of NebraskaLincolnNE68583USA
| | - Lirong Zeng
- Center for Plant Science Innovation and Department of Plant PathologyUniversity of NebraskaLincolnNE68583USA
- Southern Regional Collaborative Innovation Center for Grain and Oil CropsHunan Agricultural UniversityChangsha410128China
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Kraus CM, Mazo-Molina C, Smart CD, Martin GB. Pseudomonas syringae pv. tomato Strains from New York Exhibit Virulence Attributes Intermediate Between Typical Race 0 and Race 1 Strains. PLANT DISEASE 2017; 101:1442-1448. [PMID: 30678591 DOI: 10.1094/pdis-03-17-0330-re] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Bacterial speck disease, caused by Pseudomonas syringae pv. tomato, is a persistent problem for fresh-market tomato growers in New York. Race 0 strains of this pathogen express either or both of the type III effectors AvrPto or AvrPtoB, which are recognized by tomato varieties expressing the Pto resistance gene. Pto encodes a protein kinase that activates the host immune system, thereby inhibiting bacterial multiplication and preventing disease development. Race 1 P. syringae pv. tomato strains do not express these effectors and are virulent on tomato whether or not the variety expresses Pto. Very few fresh-market tomato varieties have the Pto gene. We collected six P. syringae pv. tomato strains from naturally infected tomato plants across New York in 2015 and characterized them for their virulence and for the presence of specific effectors. In experiments conducted in the greenhouse, all strains reached population sizes in Pto-expressing tomato leaves that were intermediate between typical race 0 and race 1 strains. This phenotype has not been observed previously and suggests that the strains are recognized by Pto but such recognition is compromised by another P. syringae pv. tomato factor. The strains were found to encode avrPto, which is transcribed and translated. They also express avrPtoB although, as reported for other P. syringae pv. tomato strains, protein expression for this effector was not detectable. Deletion of avrPto from a representative New York strain allowed it to reach high populations in Pto-expressing tomato varieties, without compromising its virulence on susceptible tomato plants. Collectively, our data suggest that introgression of the Pto gene into fresh-market tomato varieties could enhance protection against extant P. syringae pv. tomato strains.
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Affiliation(s)
- Christine M Kraus
- Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, and Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853
| | - Carolina Mazo-Molina
- Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, and Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853
| | - Christine D Smart
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University
| | - Gregory B Martin
- Boyce Thompson Institute for Plant Research, and Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University
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38
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Zhou B, Zeng L. Elucidating the role of highly homologous Nicotiana benthamiana ubiquitin E2 gene family members in plant immunity through an improved virus-induced gene silencing approach. PLANT METHODS 2017; 13:59. [PMID: 28736574 PMCID: PMC5521103 DOI: 10.1186/s13007-017-0210-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 07/17/2017] [Indexed: 05/29/2023]
Abstract
BACKGROUND Virus-induced gene silencing (VIGS) has been used in many plant species as an attractive post transcriptional gene silencing (PTGS) method for studying gene function either individually or at large-scale in a high-throughput manner. However, the specificity and efficiency for knocking down members of a highly homologous gene family have remained to date a significant challenge in VIGS due to silencing of off-targets. RESULTS Here we present an improved method for the selection and evaluation of gene fragments used for VIGS to specifically and efficiently knock down members of a highly homologous gene family. Using this method, we knocked down twelve and four members, respectively of group III of the gene family encoding ubiquitin-conjugating enzymes (E2) in Nicotiana benthamiana. Assays using these VIGS-treated plants revealed that the group III E2s are essential for plant development, plant immunity-associated reactive oxygen species (ROS) production, expression of the gene NbRbohB that is required for ROS production, and suppression of immunity-associated programmed cell death (PCD) by AvrPtoB, an effector protein of the bacterial pathogen Pseudomons syringae. Moreover, functional redundancy for plant development and ROS production was found to exist among members of group III E2s. CONCLUSIONS We have found that employment of a gene fragment as short as approximately 70 base pairs (bp) that contains at least three mismatched nucleotides to other genes within any 21-bp sequences prevents silencing of off-target(s) in VIGS. This improved approach in the selection and evaluation of gene fragments allows for specific and efficient knocking down of highly homologous members of a gene family. Using this approach, we implicated N. benthamiana group III E2s in plant development, immunity-associated ROS production, and suppression of multiple immunity-associated PCD by AvrPtoB. We also unraveled functional redundancy among group III members in their requirement for plant development and plant immunity-associated ROS production.
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Affiliation(s)
- Bangjun Zhou
- Center for Plant Science Innovation, Department of Plant Pathology, University of Nebraska, Lincoln, NE 68583 USA
| | - Lirong Zeng
- Center for Plant Science Innovation, Department of Plant Pathology, University of Nebraska, Lincoln, NE 68583 USA
- Southern Regional Collaborative Innovation Center for Grain and Oil Crops, Hunan Agricultural University, Changsha, 410128 China
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Yang B, Wang Q, Jing M, Guo B, Wu J, Wang H, Wang Y, Lin L, Wang Y, Ye W, Dong S, Wang Y. Distinct regions of the Phytophthora essential effector Avh238 determine its function in cell death activation and plant immunity suppression. THE NEW PHYTOLOGIST 2017; 214:361-375. [PMID: 28134441 DOI: 10.1111/nph.14430] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 12/09/2016] [Indexed: 05/20/2023]
Abstract
Phytophthora pathogens secrete effectors to manipulate host innate immunity, thus facilitating infection. Among the RXLR effectors highly induced during Phytophthora sojae infection, Avh238 not only contributes to pathogen virulence but also triggers plant cell death. However, the detailed molecular basis of Avh238 functions remains largely unknown. We mapped the regions responsible for Avh238 functions in pathogen virulence and plant cell death induction using a strategy that combines investigation of natural variation and large-scale mutagenesis assays. The correlation between cellular localization and Avh238 functions was also evaluated. We found that the 79th residue (histidine or leucine) of Avh238 determined its cell death-inducing activity, and that the 53 amino acids in its C-terminal region are responsible for promoting Phytophthora infection. Transient expression of Avh238 in Nicotiana benthamiana revealed that nuclear localization is essential for triggering cell death, while Avh238-mediated suppression of INF1-triggered cell death requires cytoplasmic localization. Our results demonstrate that a representative example of an essential Phytophthora RXLR effector can evolve to escape recognition by the host by mutating one nucleotide site, and can also retain plant immunosuppressive activity to enhance pathogen virulence in planta.
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Affiliation(s)
- Bo Yang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, 210095, China
| | - Qunqing Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, 210095, China
- Department of Plant Pathology, Shandong Agricultural University, Taian, 271018, China
| | - Maofeng Jing
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, 210095, China
| | - Baodian Guo
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, 210095, China
| | - Jiawei Wu
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, 210095, China
| | - Haonan Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, 210095, China
| | - Yang Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, 210095, China
| | - Long Lin
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, 210095, China
| | - Yan Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, 210095, China
| | - Wenwu Ye
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, 210095, China
| | - Suomeng Dong
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, 210095, China
| | - Yuanchao Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, 210095, China
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Yang D, Chen C, Liu Q, Jian H. Comparative analysis of pre- and post-parasitic transcriptomes and mining pioneer effectors of Heterodera avenae. Cell Biosci 2017; 7:11. [PMID: 28289537 PMCID: PMC5309974 DOI: 10.1186/s13578-017-0138-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 02/06/2017] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND The cereal cyst nematode (CCN, Heterodera avenae) is a devastating pathogen of wheat and barley crops in many countries. We aimed to prioritize genetic and molecular targets for H. avenae control via the powerful and integrative bioinformatics platform. RESULTS Here, we sequenced mRNA isolated from Chinese H. avenae at pre-parasitic (consisting of egg, J1 and hatched-J2) stages and post-parasitic (consisting of parasitic-J2, J3, J4 and adults) stages. Total 1,066,719 reads of whole life cycle transcriptomes were assembled into 10,811 contigs with N50 length of 1754 bp and 71,401 singletons. Comparative analyses of orthologous among H. avenae and 7 other nematodes with various life-styles revealed the significance and peculiarity of neurological system for sedentary phytonematode. KEGG pathway enrichment demonstrated active crosstalk events of nervous system at pre-parasitic stages, and 6 FMRFamide-like neuropeptides were verified to display an expression peak at the hatched-J2 stage in H. avenae. Furthermore, multiple approaches were undertaken to mine putative effectors and parasitism-specific genes. Notably, H. avenae might represent the first phytonematode reported to possess the pioneer effectors with RxLR motif and potential effectors with homologies to Ant-5/Ant-34. CONCLUSION Our work provides valuable resources for in-depth understanding the parasitism and pathogenicity of H. avenae, as well as developing new targets-oriented strategies on effective managements.
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Affiliation(s)
- Dan Yang
- Department of Plant Pathology, China Agricultural University, Beijing, 100193 China
| | - Changlong Chen
- Department of Plant Pathology, China Agricultural University, Beijing, 100193 China
- Institute of Crop Research, Chinese Academy of Agricultural Sciences, Beijing, 100081 China
| | - Qian Liu
- Department of Plant Pathology, China Agricultural University, Beijing, 100193 China
| | - Heng Jian
- Department of Plant Pathology, China Agricultural University, Beijing, 100193 China
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Zhou B, Mural RV, Chen X, Oates ME, Connor RA, Martin GB, Gough J, Zeng L. A Subset of Ubiquitin-Conjugating Enzymes Is Essential for Plant Immunity. PLANT PHYSIOLOGY 2017; 173:1371-1390. [PMID: 27909045 PMCID: PMC5291023 DOI: 10.1104/pp.16.01190] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 11/28/2016] [Indexed: 05/06/2023]
Abstract
Of the three classes of enzymes involved in ubiquitination, ubiquitin-conjugating enzymes (E2) have been often incorrectly considered to play merely an auxiliary role in the process, and few E2 enzymes have been investigated in plants. To reveal the role of E2 in plant innate immunity, we identified and cloned 40 tomato genes encoding ubiquitin E2 proteins. Thioester assays indicated that the majority of the genes encode enzymatically active E2. Phylogenetic analysis classified the 40 tomato E2 enzymes into 13 groups, of which members of group III were found to interact and act specifically with AvrPtoB, a Pseudomonas syringae pv tomato effector that uses its ubiquitin ligase (E3) activity to suppress host immunity. Knocking down the expression of group III E2 genes in Nicotiana benthamiana diminished the AvrPtoB-promoted degradation of the Fen kinase and the AvrPtoB suppression of host immunity-associated programmed cell death. Importantly, silencing group III E2 genes also resulted in reduced pattern-triggered immunity (PTI). By contrast, programmed cell death induced by several effector-triggered immunity elicitors was not affected on group III-silenced plants. Functional characterization suggested redundancy among group III members for their role in the suppression of plant immunity by AvrPtoB and in PTI and identified UBIQUITIN-CONJUGATING11 (UBC11), UBC28, UBC29, UBC39, and UBC40 as playing a more significant role in PTI than other group III members. Our work builds a foundation for the further characterization of E2s in plant immunity and reveals that AvrPtoB has evolved a strategy for suppressing host immunity that is difficult for the plant to thwart.
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Affiliation(s)
- Bangjun Zhou
- Plant Science Innovation Center and Plant Pathology Department, University of Nebraska, Lincoln, Nebraska 68583 (B.Z., L.Z.)
- Biology Department, University of Arkansas, Little Rock, Arkansas 72204 (B.Z., R.V.M., X.C., R.A.C., L.Z.)
- Department of Computer Science, University of Bristol, Bristol BS8 1UB, United Kingdom (M.E.O., J.G.)
- Boyce Thompson Institute for Plant Research and Department of Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853 (G.B.M.); and
- Southern Regional Collaborative Innovation Center for Grain and Oil Crops, Hunan Agricultural University, Changsha 410128, China (L.Z.)
| | - Ravi V Mural
- Plant Science Innovation Center and Plant Pathology Department, University of Nebraska, Lincoln, Nebraska 68583 (B.Z., L.Z.)
- Biology Department, University of Arkansas, Little Rock, Arkansas 72204 (B.Z., R.V.M., X.C., R.A.C., L.Z.)
- Department of Computer Science, University of Bristol, Bristol BS8 1UB, United Kingdom (M.E.O., J.G.)
- Boyce Thompson Institute for Plant Research and Department of Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853 (G.B.M.); and
- Southern Regional Collaborative Innovation Center for Grain and Oil Crops, Hunan Agricultural University, Changsha 410128, China (L.Z.)
| | - Xuanyang Chen
- Plant Science Innovation Center and Plant Pathology Department, University of Nebraska, Lincoln, Nebraska 68583 (B.Z., L.Z.)
- Biology Department, University of Arkansas, Little Rock, Arkansas 72204 (B.Z., R.V.M., X.C., R.A.C., L.Z.)
- Department of Computer Science, University of Bristol, Bristol BS8 1UB, United Kingdom (M.E.O., J.G.)
- Boyce Thompson Institute for Plant Research and Department of Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853 (G.B.M.); and
- Southern Regional Collaborative Innovation Center for Grain and Oil Crops, Hunan Agricultural University, Changsha 410128, China (L.Z.)
| | - Matt E Oates
- Plant Science Innovation Center and Plant Pathology Department, University of Nebraska, Lincoln, Nebraska 68583 (B.Z., L.Z.)
- Biology Department, University of Arkansas, Little Rock, Arkansas 72204 (B.Z., R.V.M., X.C., R.A.C., L.Z.)
- Department of Computer Science, University of Bristol, Bristol BS8 1UB, United Kingdom (M.E.O., J.G.)
- Boyce Thompson Institute for Plant Research and Department of Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853 (G.B.M.); and
- Southern Regional Collaborative Innovation Center for Grain and Oil Crops, Hunan Agricultural University, Changsha 410128, China (L.Z.)
| | - Richard A Connor
- Plant Science Innovation Center and Plant Pathology Department, University of Nebraska, Lincoln, Nebraska 68583 (B.Z., L.Z.)
- Biology Department, University of Arkansas, Little Rock, Arkansas 72204 (B.Z., R.V.M., X.C., R.A.C., L.Z.)
- Department of Computer Science, University of Bristol, Bristol BS8 1UB, United Kingdom (M.E.O., J.G.)
- Boyce Thompson Institute for Plant Research and Department of Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853 (G.B.M.); and
- Southern Regional Collaborative Innovation Center for Grain and Oil Crops, Hunan Agricultural University, Changsha 410128, China (L.Z.)
| | - Gregory B Martin
- Plant Science Innovation Center and Plant Pathology Department, University of Nebraska, Lincoln, Nebraska 68583 (B.Z., L.Z.)
- Biology Department, University of Arkansas, Little Rock, Arkansas 72204 (B.Z., R.V.M., X.C., R.A.C., L.Z.)
- Department of Computer Science, University of Bristol, Bristol BS8 1UB, United Kingdom (M.E.O., J.G.)
- Boyce Thompson Institute for Plant Research and Department of Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853 (G.B.M.); and
- Southern Regional Collaborative Innovation Center for Grain and Oil Crops, Hunan Agricultural University, Changsha 410128, China (L.Z.)
| | - Julian Gough
- Plant Science Innovation Center and Plant Pathology Department, University of Nebraska, Lincoln, Nebraska 68583 (B.Z., L.Z.)
- Biology Department, University of Arkansas, Little Rock, Arkansas 72204 (B.Z., R.V.M., X.C., R.A.C., L.Z.)
- Department of Computer Science, University of Bristol, Bristol BS8 1UB, United Kingdom (M.E.O., J.G.)
- Boyce Thompson Institute for Plant Research and Department of Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853 (G.B.M.); and
- Southern Regional Collaborative Innovation Center for Grain and Oil Crops, Hunan Agricultural University, Changsha 410128, China (L.Z.)
| | - Lirong Zeng
- Plant Science Innovation Center and Plant Pathology Department, University of Nebraska, Lincoln, Nebraska 68583 (B.Z., L.Z.);
- Biology Department, University of Arkansas, Little Rock, Arkansas 72204 (B.Z., R.V.M., X.C., R.A.C., L.Z.);
- Department of Computer Science, University of Bristol, Bristol BS8 1UB, United Kingdom (M.E.O., J.G.);
- Boyce Thompson Institute for Plant Research and Department of Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853 (G.B.M.); and
- Southern Regional Collaborative Innovation Center for Grain and Oil Crops, Hunan Agricultural University, Changsha 410128, China (L.Z.)
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Maia T, Badel JL, Marin‐Ramirez G, Rocha CDM, Fernandes MB, da Silva JCF, de Azevedo‐Junior GM, Brommonschenkel SH. The Hemileia vastatrix effector HvEC-016 suppresses bacterial blight symptoms in coffee genotypes with the S H 1 rust resistance gene. THE NEW PHYTOLOGIST 2017; 213:1315-1329. [PMID: 27918080 PMCID: PMC6079635 DOI: 10.1111/nph.14334] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 10/16/2016] [Indexed: 05/03/2023]
Abstract
A number of genes that confer resistance to coffee leaf rust (SH 1-SH 9) have been identified within the genus Coffea, but despite many years of research on this pathosystem, the complementary avirulence genes of Hemileia vastatrix have not been reported. After identification of H. vastatrix effector candidate genes (HvECs) expressed at different stages of its lifecycle, we established an assay to characterize HvEC proteins by delivering them into coffee cells via the type-three secretion system (T3SS) of Pseudomonas syringae pv. garcae (Psgc). Employing a calmodulin-dependent adenylate cyclase assay, we demonstrate that Psgc recognizes a heterologous P. syringae T3SS secretion signal which enables us to translocate HvECs into the cytoplasm of coffee cells. Using this Psgc-adapted effector detector vector (EDV) system, we found that HvEC-016 suppresses the growth of Psgc on coffee genotypes with the SH 1 resistance gene. Suppression of bacterial blight symptoms in SH 1 plants was associated with reduced bacterial multiplication. By contrast, HvEC-016 enhanced bacterial multiplication in SH 1-lacking plants. Our findings suggest that HvEC-016 may be recognized by the plant immune system in a SH 1-dependent manner. Thus, our experimental approach is an effective tool for the characterization of effector/avirulence proteins of this important pathogen.
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Affiliation(s)
- Thiago Maia
- Departamento de Fitopatologia and National Institute for Plant‐Pest Interactions/Instituto de Biotecnologia Aplicada a Agropecuária‐BIOAGROUniversidade Federal de ViçosaViçosaMG 36570‐000Brazil
| | - Jorge L. Badel
- Departamento de Fitopatologia and National Institute for Plant‐Pest Interactions/Instituto de Biotecnologia Aplicada a Agropecuária‐BIOAGROUniversidade Federal de ViçosaViçosaMG 36570‐000Brazil
| | - Gustavo Marin‐Ramirez
- Departamento de Fitopatologia and National Institute for Plant‐Pest Interactions/Instituto de Biotecnologia Aplicada a Agropecuária‐BIOAGROUniversidade Federal de ViçosaViçosaMG 36570‐000Brazil
| | - Cynthia de M. Rocha
- Departamento de Fitopatologia and National Institute for Plant‐Pest Interactions/Instituto de Biotecnologia Aplicada a Agropecuária‐BIOAGROUniversidade Federal de ViçosaViçosaMG 36570‐000Brazil
| | - Michelle B. Fernandes
- Departamento de Fitopatologia and National Institute for Plant‐Pest Interactions/Instituto de Biotecnologia Aplicada a Agropecuária‐BIOAGROUniversidade Federal de ViçosaViçosaMG 36570‐000Brazil
| | - José C. F. da Silva
- Departamento de Fitopatologia and National Institute for Plant‐Pest Interactions/Instituto de Biotecnologia Aplicada a Agropecuária‐BIOAGROUniversidade Federal de ViçosaViçosaMG 36570‐000Brazil
| | - Gilson M. de Azevedo‐Junior
- Departamento de Fitopatologia and National Institute for Plant‐Pest Interactions/Instituto de Biotecnologia Aplicada a Agropecuária‐BIOAGROUniversidade Federal de ViçosaViçosaMG 36570‐000Brazil
| | - Sérgio H. Brommonschenkel
- Departamento de Fitopatologia and National Institute for Plant‐Pest Interactions/Instituto de Biotecnologia Aplicada a Agropecuária‐BIOAGROUniversidade Federal de ViçosaViçosaMG 36570‐000Brazil
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Castañeda-Ojeda MP, Moreno-Pérez A, Ramos C, López-Solanilla E. Suppression of Plant Immune Responses by the Pseudomonas savastanoi pv. savastanoi NCPPB 3335 Type III Effector Tyrosine Phosphatases HopAO1 and HopAO2. FRONTIERS IN PLANT SCIENCE 2017; 8:680. [PMID: 28529516 PMCID: PMC5418354 DOI: 10.3389/fpls.2017.00680] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 04/13/2017] [Indexed: 05/12/2023]
Abstract
The effector repertoire of the olive pathogen P. savastanoi pv. savastanoi NCPPB 3335 includes two members of the HopAO effector family, one of the most diverse T3E families of the P. syringae complex. The study described here explores the phylogeny of these dissimilar members, HopAO1 and HopAO2, among the complex and reveals their activities as immune defense suppressors. Although HopAO1 is predominantly encoded by phylogroup 3 strains isolated from woody organs of woody hosts, both HopAO1 and HopAO2 are phylogenetically clustered according to the woody/herbaceous nature of their host of isolation, suggesting host specialization of the HopAO family across the P. syringae complex. HopAO1 and HopAO2 translocate into plant cells and show hrpL-dependent expression, which allows their classification as actively deployed type III effectors. Our data also show that HopAO1 and HopAO2 possess phosphatase activity, a hallmark of the members of this family. Both of them exert an inhibitory effect on early plant defense responses, such as ROS production and callose deposition, and are able to suppress ETI responses induced by the effectorless polymutant of P. syringae pv. tomato DC3000 (DC3000D28E) in Nicotiana. Moreover, we demonstrate that a ΔhopAO1 mutant of P. savastanoi NCPBB 3335 exhibits a reduced fitness and virulence in olive plants, which supports the relevance of this effector during the interaction of this strain with its host plants. This work contributes to the field with the first report regarding functional analysis of HopAO homologs encoded by P. syringae or P. savastanoi strains isolated from woody hosts.
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Affiliation(s)
- María Pilar Castañeda-Ojeda
- Área de Genética, Facultad de Ciencias, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga – Consejo Superior de Investigaciones CientíficasMálaga, Spain
| | - Alba Moreno-Pérez
- Área de Genética, Facultad de Ciencias, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga – Consejo Superior de Investigaciones CientíficasMálaga, Spain
| | - Cayo Ramos
- Área de Genética, Facultad de Ciencias, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga – Consejo Superior de Investigaciones CientíficasMálaga, Spain
| | - Emilia López-Solanilla
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid – Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Parque Científico y Tecnológico de la UPMMadrid, Spain
- Departamento de Biotecnología y Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de MadridMadrid, Spain
- *Correspondence: Emilia López-Solanilla,
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Choi S, Jayaraman J, Segonzac C, Park HJ, Park H, Han SW, Sohn KH. Pseudomonas syringae pv. actinidiae Type III Effectors Localized at Multiple Cellular Compartments Activate or Suppress Innate Immune Responses in Nicotiana benthamiana. FRONTIERS IN PLANT SCIENCE 2017; 8:2157. [PMID: 29326748 PMCID: PMC5742410 DOI: 10.3389/fpls.2017.02157] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 12/06/2017] [Indexed: 05/15/2023]
Abstract
Bacterial phytopathogen type III secreted (T3S) effectors have been strongly implicated in altering the interaction of pathogens with host plants. Therefore, it is useful to characterize the whole effector repertoire of a pathogen to understand the interplay of effectors in plants. Pseudomonas syringae pv. actinidiae is a causal agent of kiwifruit canker disease. In this study, we generated an Agrobacterium-mediated transient expression library of YFP-tagged T3S effectors from two strains of Psa, Psa-NZ V13 and Psa-NZ LV5, in order to gain insight into their mode of action in Nicotiana tabacum and N. benthamiana. Determining the subcellular localization of effectors gives an indication of the possible host targets of effectors. A confocal microscopy assay detecting YFP-tagged Psa effectors revealed that the nucleus, cytoplasm and cell periphery are major targets of Psa effectors. Agrobacterium-mediated transient expression of multiple Psa effectors induced HR-like cell death (HCD) in Nicotiana spp., suggesting that multiple Psa effectors may be recognized by Nicotiana spp.. Virus-induced gene silencing (VIGS) of several known plant immune regulators, EDS1, NDR1, or SGT1 specified the requirement of SGT1 in HCD induced by several Psa effectors in N. benthamiana. In addition, the suppression activity of Psa effectors on HCD-inducing proteins and PTI was assessed. Psa effectors showed differential suppression activities on each HCD inducer or PTI. Taken together, our Psa effector repertoire analysis highlights the great diversity of T3S effector functions in planta.
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Affiliation(s)
- Sera Choi
- Bioprotection Research Centre, Institute of Agriculture and Environment, Massey University, Palmerston North, New Zealand
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, South Korea
| | - Jay Jayaraman
- Bioprotection Research Centre, Institute of Agriculture and Environment, Massey University, Palmerston North, New Zealand
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, South Korea
| | - Cécile Segonzac
- Plant Science Department, Plant Genomics and Breeding Institute and Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea
| | - Hye-Jee Park
- Department of Integrative Plant Science, Chung-Ang University, Anseong, South Korea
| | - Hanbi Park
- Department of Integrative Plant Science, Chung-Ang University, Anseong, South Korea
| | - Sang-Wook Han
- Department of Integrative Plant Science, Chung-Ang University, Anseong, South Korea
| | - Kee Hoon Sohn
- Bioprotection Research Centre, Institute of Agriculture and Environment, Massey University, Palmerston North, New Zealand
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, South Korea
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, South Korea
- *Correspondence: Kee Hoon Sohn,
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Chen C, Chen Y, Jian H, Yang D, Dai Y, Pan L, Shi F, Yang S, Liu Q. Large-Scale Identification and Characterization of Heterodera avenae Putative Effectors Suppressing or Inducing Cell Death in Nicotiana benthamiana. FRONTIERS IN PLANT SCIENCE 2017; 8:2062. [PMID: 29379510 PMCID: PMC5775296 DOI: 10.3389/fpls.2017.02062] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 11/17/2017] [Indexed: 05/06/2023]
Abstract
Heterodera avenae is one of the most important plant pathogens and causes vast losses in cereal crops. As a sedentary endoparasitic nematode, H. avenae secretes effectors that modify plant defenses and promote its biotrophic infection of its hosts. However, the number of effectors involved in the interaction between H. avenae and host defenses remains unclear. Here, we report the identification of putative effectors in H. avenae that regulate plant defenses on a large scale. Our results showed that 78 of the 95 putative effectors suppressed programmed cell death (PCD) triggered by BAX and that 7 of the putative effectors themselves caused cell death in Nicotiana benthamiana. Among the cell-death-inducing effectors, three were found to be dependent on their specific domains to trigger cell death and to be expressed in esophageal gland cells by in situ hybridization. Ten candidate effectors that suppressed BAX-triggered PCD also suppressed PCD triggered by the elicitor PsojNIP and at least one R-protein/cognate effector pair, suggesting that they are active in suppressing both pattern-triggered immunity (PTI) and effector-triggered immunity (ETI). Notably, with the exception of isotig16060, these putative effectors could also suppress PCD triggered by cell-death-inducing effectors from H. avenae, indicating that those effectors may cooperate to promote nematode parasitism. Collectively, our results indicate that the majority of the tested effectors of H. avenae may play important roles in suppressing cell death induced by different elicitors in N. benthamiana.
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Affiliation(s)
- Changlong Chen
- Key Laboratory of Pest Monitoring and Green Management, Ministry of Agriculture, Department of Plant Pathology, China Agricultural University, Beijing, China
- Beijing Agro-Biotechnology Research Center, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Yongpan Chen
- Key Laboratory of Pest Monitoring and Green Management, Ministry of Agriculture, Department of Plant Pathology, China Agricultural University, Beijing, China
| | - Heng Jian
- Key Laboratory of Pest Monitoring and Green Management, Ministry of Agriculture, Department of Plant Pathology, China Agricultural University, Beijing, China
| | - Dan Yang
- Key Laboratory of Pest Monitoring and Green Management, Ministry of Agriculture, Department of Plant Pathology, China Agricultural University, Beijing, China
| | - Yiran Dai
- Key Laboratory of Pest Monitoring and Green Management, Ministry of Agriculture, Department of Plant Pathology, China Agricultural University, Beijing, China
| | - Lingling Pan
- Key Laboratory of Pest Monitoring and Green Management, Ministry of Agriculture, Department of Plant Pathology, China Agricultural University, Beijing, China
- Qinzhou Entry-Exit Inspection and Quarantine Bureau, Guangxi, China
| | - Fengwei Shi
- Key Laboratory of Pest Monitoring and Green Management, Ministry of Agriculture, Department of Plant Pathology, China Agricultural University, Beijing, China
- Central Political and Legal Affairs Commission of CPC Chengwu County Committee, Shandong, China
| | - Shanshan Yang
- Key Laboratory of Pest Monitoring and Green Management, Ministry of Agriculture, Department of Plant Pathology, China Agricultural University, Beijing, China
| | - Qian Liu
- Key Laboratory of Pest Monitoring and Green Management, Ministry of Agriculture, Department of Plant Pathology, China Agricultural University, Beijing, China
- *Correspondence: Qian Liu,
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Zhuo K, Chen J, Lin B, Wang J, Sun F, Hu L, Liao J. A novel Meloidogyne enterolobii effector MeTCTP promotes parasitism by suppressing programmed cell death in host plants. MOLECULAR PLANT PATHOLOGY 2017; 18:45-54. [PMID: 26808010 PMCID: PMC6638250 DOI: 10.1111/mpp.12374] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 01/20/2016] [Accepted: 01/21/2016] [Indexed: 05/20/2023]
Abstract
Meloidogyne enterolobii is one of the most important plant-parasitic nematodes that can overcome the Mi-1 resistance gene and damage many economically important crops. Translationally controlled tumour protein (TCTP) is a multifunctional protein that exists in various eukaryotes and plays an important role in parasitism. In this study, a novel M. enterolobii TCTP effector, named MeTCTP, was identified and functionally characterized. MeTCTP was specifically expressed within the dorsal gland and was up-regulated during M. enterolobii parasitism. Transient expression of MeTCTP in protoplasts from tomato roots showed that MeTCTP was localized in the cytoplasm of the host cells. Transgenic Arabidopsis thaliana plants overexpressing MeTCTP were more susceptible to M. enterolobii infection than wild-type plants in a dose-dependent manner. By contrast, in planta RNA interference (RNAi) targeting MeTCTP suppressed the expression of MeTCTP in infecting nematodes and attenuated their parasitism. Furthermore, MeTCTP could suppress programmed cell death triggered by the pro-apoptotic protein BAX. These results demonstrate that MeTCTP is a novel plant-parasitic nematode effector that promotes parasitism, probably by suppressing programmed cell death in host plants.
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Affiliation(s)
- Kan Zhuo
- Laboratory of Plant NematologySouth China Agricultural UniversityGuangzhou510642China
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhou510642China
| | - Jiansong Chen
- Laboratory of Plant NematologySouth China Agricultural UniversityGuangzhou510642China
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhou510642China
| | - Borong Lin
- Laboratory of Plant NematologySouth China Agricultural UniversityGuangzhou510642China
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhou510642China
| | - Jing Wang
- Laboratory of Plant NematologySouth China Agricultural UniversityGuangzhou510642China
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhou510642China
| | - Fengxia Sun
- Laboratory of Plant NematologySouth China Agricultural UniversityGuangzhou510642China
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhou510642China
| | - Lili Hu
- Laboratory of Plant NematologySouth China Agricultural UniversityGuangzhou510642China
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhou510642China
| | - Jinling Liao
- Laboratory of Plant NematologySouth China Agricultural UniversityGuangzhou510642China
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhou510642China
- Guangdong Vocational College of Ecological EngineeringGuangzhou510520China
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Ramachandran SR, Yin C, Kud J, Tanaka K, Mahoney AK, Xiao F, Hulbert SH. Effectors from Wheat Rust Fungi Suppress Multiple Plant Defense Responses. PHYTOPATHOLOGY 2017; 107:75-83. [PMID: 27503371 DOI: 10.1094/phyto-02-16-0083-r] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Fungi that cause cereal rust diseases (genus Puccinia) are important pathogens of wheat globally. Upon infection, the fungus secretes a number of effector proteins. Although a large repository of putative effectors has been predicted using bioinformatic pipelines, the lack of available high-throughput effector screening systems has limited functional studies on these proteins. In this study, we mined the available transcriptomes of Puccinia graminis and P. striiformis to look for potential effectors that suppress host hypersensitive response (HR). Twenty small (<300 amino acids), secreted proteins, with no predicted functions were selected for the HR suppression assay using Nicotiana benthamiana, in which each of the proteins were transiently expressed and evaluated for their ability to suppress HR caused by four cytotoxic effector-R gene combinations (Cp/Rx, ATR13/RPP13, Rpt2/RPS-2, and GPA/RBP-1) and one mutated R gene-Pto(Y207D). Nine out of twenty proteins, designated Shr1 to Shr9 (suppressors of hypersensitive response), were found to suppress HR in N. benthamiana. These effectors varied in the effector-R gene defenses they suppressed, indicating these pathogens can interfere with a variety of host defense pathways. In addition to HR suppression, effector Shr7 also suppressed PAMP-triggered immune response triggered by flg22. Finally, delivery of Shr7 through Pseudomonas fluorescens EtHAn suppressed nonspecific HR induced by Pseudomonas syringae DC3000 in wheat, confirming its activity in a homologous system. Overall, this study provides the first evidence for the presence of effectors in Puccinia species suppressing multiple plant defense responses.
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Affiliation(s)
- Sowmya R Ramachandran
- First, second, fourth, fifth, and seventh authors: Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430; and third and sixth authors: Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844-2339
| | - Chuntao Yin
- First, second, fourth, fifth, and seventh authors: Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430; and third and sixth authors: Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844-2339
| | - Joanna Kud
- First, second, fourth, fifth, and seventh authors: Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430; and third and sixth authors: Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844-2339
| | - Kiwamu Tanaka
- First, second, fourth, fifth, and seventh authors: Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430; and third and sixth authors: Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844-2339
| | - Aaron K Mahoney
- First, second, fourth, fifth, and seventh authors: Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430; and third and sixth authors: Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844-2339
| | - Fangming Xiao
- First, second, fourth, fifth, and seventh authors: Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430; and third and sixth authors: Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844-2339
| | - Scot H Hulbert
- First, second, fourth, fifth, and seventh authors: Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430; and third and sixth authors: Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844-2339
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48
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Sultanov RI, Arapidi GP, Vinogradova SV, Govorun VM, Luster DG, Ignatov AN. Comprehensive analysis of draft genomes of two closely related pseudomonas syringae phylogroup 2b strains infecting mono- and dicotyledon host plants. BMC Genomics 2016; 17:1010. [PMID: 28105943 PMCID: PMC5249006 DOI: 10.1186/s12864-016-3358-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Background In recent years, the damage caused by bacterial pathogens to major crops has been increasing worldwide. Pseudomonas syringae is a widespread bacterial species that infects almost all major crops. Different P. syringae strains use a wide range of biochemical mechanisms, including phytotoxins and effectors of the type III and type IV secretion systems, which determine the specific nature of the pathogen virulence. Results Strains 1845 (isolated from dicots) and 2507 (isolated from monocots) were selected for sequencing because they specialize on different groups of plants. We compared virulence factors in these and other available genomes of phylogroup 2 to find genes responsible for the specialization of bacteria. We showed that strain 1845 belongs to the clonal group that has been infecting monocots in Russia and USA for a long time (at least 50 years). Strain 1845 has relatively recently changed its host plant to dicots. Conclusions The results obtained by comparing the strain 1845 genome with the genomes of bacteria infecting monocots can help to identify the genes that define specific nature of the virulence of P. syringae strains. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-3358-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rinat I Sultanov
- Moscow Institute of Physics and Technology (State University), Moscow, Russia.,Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, the Russian Academy of Sciences, Moscow, Russia
| | - Georgij P Arapidi
- Moscow Institute of Physics and Technology (State University), Moscow, Russia.,Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, the Russian Academy of Sciences, Moscow, Russia
| | | | - Vadim M Govorun
- Moscow Institute of Physics and Technology (State University), Moscow, Russia.,Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, the Russian Academy of Sciences, Moscow, Russia.,SRCC of Physical-Chemical Medicine, Moscow, Russia
| | - Duglas G Luster
- USDA-ARS Foreign Disease - Weed Science Research Unit, Ft. Detrick, Washington, DC, USA
| | - Alexander N Ignatov
- Russian Peoples' Friendship University, Moscow, Russia. .,R&D Center "PhytoEngineering" LLC, Moscow region, Russia.
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49
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Liu X, Cai Y, Zhang X, Zhang H, Zheng X, Zhang Z. Carbamoyl Phosphate Synthetase Subunit MoCpa2 Affects Development and Pathogenicity by Modulating Arginine Biosynthesis in Magnaporthe oryzae. Front Microbiol 2016; 7:2023. [PMID: 28066349 PMCID: PMC5166579 DOI: 10.3389/fmicb.2016.02023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 12/02/2016] [Indexed: 01/09/2023] Open
Abstract
Arginine is a semi-essential amino acid that affects physiological and biochemical functions. The CPA2 gene in yeast encodes a large subunit of arginine-specific carbamoyl phosphate synthetase (CPS) and is involved in arginine biosynthesis. Here, an ortholog of yeast CPA2 was identified in the rice blast fungus Magnaporthe oryzae, and was named MoCPA2. MoCpa2 is an 1180-amino acid protein which contains an ATP grasp domain and two CPSase domains. Targeted deletion of MoCPA2 supported its role in de novo arginine biosynthesis in M. oryzae as mutant phenotypes were complemented by arginine but not ornithine. The ΔMocpa2 mutant exhibited defects in asexual development and pathogenicity but not appressorium formation. Further examination revealed that the invasive hyphae of the ΔMocpa2 mutant were restricted mainly to the primary infected cells. In addition, the ΔMocpa2 mutant was unable to induce a plant defense response and had the ability to scavenge ROS during pathogen-plant interactions. Structure analysis revealed that the ATP grasp domain and each CPS domain were indispensable for the proper localization and full function of MoCpa2. In summary, our results indicate that MoCpa2 plays an important role in arginine biosynthesis, and affects growth, conidiogenesis, and pathogenicity. These results suggest that research into metabolism and processes that mediate amino acid synthesis are valuable for understanding M. oryzae pathogenesis.
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Affiliation(s)
- Xinyu Liu
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University Nanjing, China
| | - Yongchao Cai
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University Nanjing, China
| | - Xi Zhang
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University Nanjing, China
| | - Haifeng Zhang
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University Nanjing, China
| | - Xiaobo Zheng
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University Nanjing, China
| | - Zhengguang Zhang
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University Nanjing, China
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Li X, Yang D, Niu J, Zhao J, Jian H. De Novo Analysis of the Transcriptome of Meloidogyne enterolobii to Uncover Potential Target Genes for Biological Control. Int J Mol Sci 2016; 17:E1442. [PMID: 27598122 PMCID: PMC5037721 DOI: 10.3390/ijms17091442] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 08/19/2016] [Accepted: 08/24/2016] [Indexed: 12/03/2022] Open
Abstract
Meloidogyne enterolobii is one of the obligate biotrophic root-knot nematodes that has the ability to reproduce on many economically-important crops. We carried out de novo sequencing of the transcriptome of M. enterolobii using Roche GS FLX and obtained 408,663 good quality reads that were assembled into 8193 contigs and 31,860 singletons. We compared the transcripts in different nematodes that were potential targets for biological control. These included the transcripts that putatively coded for CAZymes, kinases, neuropeptide genes and secretory proteins and those that were involved in the RNAi pathway and immune signaling. Typically, 75 non-membrane secretory proteins with signal peptides secreted from esophageal gland cells were identified as putative effectors, three of which were preliminarily examined using a PVX (pGR107)-based high-throughput transient plant expression system in Nicotiana benthamiana (N. benthamiana). Results showed that these candidate proteins suppressed the programmed cell death (PCD) triggered by the pro-apoptosis protein BAX, and one protein also caused necrosis, suggesting that they might suppress plant immune responses to promote pathogenicity. In conclusion, the current study provides comprehensive insight into the transcriptome of M. enterolobii for the first time and lays a foundation for further investigation and biological control strategies.
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Affiliation(s)
- Xiangyang Li
- Department of Plant Pathology, China Agricultural University, Beijing 100193, China.
- Beijing University of Agriculture, Beijing 102206, China.
| | - Dan Yang
- Department of Plant Pathology, China Agricultural University, Beijing 100193, China.
| | - Junhai Niu
- Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou 571737, China.
- Hainan Engineering Technology Research Center for Tropical Ornamental Plant Germplasm Innovation and Utilization, Danzhou 571737, China.
| | - Jianlong Zhao
- Department of Plant Pathology, China Agricultural University, Beijing 100193, China.
| | - Heng Jian
- Department of Plant Pathology, China Agricultural University, Beijing 100193, China.
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