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Jin Y, Zhang W, Cong S, Zhuang QG, Gu YL, Ma YN, Filiatrault MJ, Li JZ, Wei HL. Pseudomonas syringae Type III Secretion Protein HrpP Manipulates Plant Immunity To Promote Infection. Microbiol Spectr 2023; 11:e0514822. [PMID: 37067445 PMCID: PMC10269811 DOI: 10.1128/spectrum.05148-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 03/22/2023] [Indexed: 04/18/2023] Open
Abstract
The bacterial plant pathogen Pseudomonas syringae deploys a type III secretion system (T3SS) to deliver effector proteins into plant cells to facilitate infection, for which many effectors have been characterized for their interactions. However, few T3SS Hrp (hypersensitive response and pathogenicity) proteins from the T3SS secretion apparatus have been studied for their direct interactions with plants. Here, we show that the P. syringae pv. tomato DC3000 T3SS protein HrpP induces host cell death, suppresses pattern-triggered immunity (PTI), and restores the effector translocation ability of the hrpP mutant. The hrpP-transgenic Arabidopsis lines exhibited decreased PTI responses to flg22 and elf18 and enhanced disease susceptibility to P. syringae pv. tomato DC3000. Transcriptome analysis reveals that HrpP sensing activates salicylic acid (SA) signaling while suppressing jasmonic acid (JA) signaling, which correlates with increased SA accumulation and decreased JA biosynthesis. Both yeast two-hybrid and bimolecular fluorescence complementation assays show that HrpP interacts with mitogen-activated protein kinase kinase 2 (MKK2) on the plant membrane and in the nucleus. The HrpP truncation HrpP1-119, rather than HrpP1-101, retains the ability to interact with MKK2 and suppress PTI in plants. In contrast, HrpP1-101 continues to cause cell death and electrolyte leakage. MKK2 silencing compromises SA signaling but has no effect on cell death caused by HrpP. Overall, our work highlights that the P. syringae T3SS protein HrpP facilitates effector translocation and manipulates plant immunity to facilitate bacterial infection. IMPORTANCE The T3SS is required for the virulence of many Gram-negative bacterial pathogens of plants and animals. This study focuses on the sensing and function of the T3SS protein HrpP during plant interactions. Our findings show that HrpP and its N-terminal truncation HrpP1-119 can interact with MKK2, promote effector translocation, and manipulate plant immunity to facilitate bacterial infection, highlighting the P. syringae T3SS component involved in the fine-tuning of plant immunity.
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Affiliation(s)
- Ya Jin
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Wei Zhang
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, New York, USA
| | - Shen Cong
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Qi-Guo Zhuang
- China-New Zealand Belt and Road Joint Laboratory on Kiwifruit, Kiwifruit Breeding and Utilization Key Laboratory of Sichuan Province, Sichuan Provincial Academy of Natural Resource Sciences, Chengdu, China
| | - Yi-Lin Gu
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yi-Nan Ma
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Melanie J. Filiatrault
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, New York, USA
- Emerging Pests and Pathogens Research Unit, Agricultural Research Service, United States Department of Agriculture, Robert W. Holley Center for Agriculture and Health, Ithaca, New York, USA
| | - Jun-Zhou Li
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Hai-Lei Wei
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
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Basit F, Bhat JA, Alyemeni MN, Shah T, Ahmad P. Nitric oxide mitigates vanadium toxicity in soybean (Glycine max L.) by modulating reactive oxygen species (ROS) and antioxidant system. JOURNAL OF HAZARDOUS MATERIALS 2023; 451:131085. [PMID: 36870130 DOI: 10.1016/j.jhazmat.2023.131085] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 02/12/2023] [Accepted: 02/23/2023] [Indexed: 06/18/2023]
Abstract
Vanadium (V) induced hazardous effects posturing a serious concern on crop production as well as food security. However, the nitric oxide (NO)-mediated alleviation of V-induced oxidative stress in soybean seedlings is still unknown. Therefore, this research was designed to explore the effects of exogenous NO to mitigate the V-induced phytotoxicity in soybean plants. Our upshots disclosed that NO supplementation considerably improved the plant biomass, growth, and photosynthetic attributes by regulating the carbohydrates, and plants biochemical composition, which further improved the guard cells, and stomatal aperture of soybean leaves. Additionally, NO regulated the plant hormones, and phenolic profile which restricted the V contents absorption (65.6%), and translocation (57.9%) by maintaining the nutrient acquisition. Furthermore, it detoxified the excessive V contents, and upsurged the antioxidants defense mechanism to lower the MDA, and scavenge ROS production. The molecular analysis further verified the NO-based regulation of lipid, sugar production, and degradation as well as detoxification mechanism in the soybean seedlings. Exclusively, we elaborated very first time the behind mechanism of V-induced oxidative stress alleviation by exogenous NO, hence illustrating the NO supplementation role as a stress alleviating agent for soybean grown in V contaminated areas to elevate the crop development and production.
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Affiliation(s)
- Farwa Basit
- Institute of Crop Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
| | | | - Mohammed Nasser Alyemeni
- Botany and Microbiology Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Tariq Shah
- Plant Science Research Unit, United States Department for Agriculture (USDA), ARS, Raleigh, NC, USA
| | - Parvaiz Ahmad
- Department of Botany, GDC, Pulwama, Jammu and Kashmir 192301, India.
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Kvitko BH, Collmer A. Discovery of the Hrp Type III Secretion System in Phytopathogenic Bacteria: How Investigation of Hypersensitive Cell Death in Plants Led to a Novel Protein Injector System and a World of Inter-Organismal Molecular Interactions Within Plant Cells. PHYTOPATHOLOGY 2023; 113:626-636. [PMID: 37099273 DOI: 10.1094/phyto-08-22-0292-kd] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
In the early 1960s, Pseudomonas syringae and other host-specific phytopathogenic proteobacteria were discovered to elicit a rapid, resistance-associated death when infiltrated at high inoculum levels into nonhost tobacco leaves. This hypersensitive reaction (or response; HR) was a useful indicator of basic pathogenic ability. Research over the next 20 years failed to identify an elicitor of the HR but revealed that its elicitation required contact between metabolically active bacterial and plant cells. Beginning in the early 1980s, molecular genetic tools were applied to the HR puzzle, revealing the presence in P. syringae of clusters of hrp genes, so named because they are required for the HR and pathogenicity, and of avr genes, so named because their presence confers HR-associated avirulence in resistant cultivars of a host plant species. A series of breakthroughs over the next two decades revealed that (i) hrp gene clusters encode a type III secretion system (T3SS), which injects Avr (now "effector") proteins into plant cells, where their recognition triggers the HR; (ii) T3SSs, which are typically present in pathogenicity islands acquired by horizontal gene transfers, are found in many bacterial pathogens of plants and animals and inject many effector proteins, which are collectively essential for pathogenicity; and (iii) a primary function of phytopathogen effectors is to subvert non-HR defenses resulting from recognition of conserved microbial features presented outside of plant cells. In the 2000s, Hrp system research shifted to extracellular components enabling effector delivery across plant cell walls and plasma membranes, regulation, and tools for studying effectors. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Brian H Kvitko
- Department of Plant Pathology, University of Georgia, 120 Carlton St., Athens, GA 30602
| | - Alan Collmer
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, 334 Plant Science Bldg., Ithaca, NY 14853
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Kongala SI, Mamidala P. Harpin-loaded chitosan nanoparticles induced defense responses in tobacco. CARBOHYDRATE POLYMER TECHNOLOGIES AND APPLICATIONS 2023. [DOI: 10.1016/j.carpta.2023.100293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
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Maekawa T, Kashkar H, Coll NS. Dying in self-defence: a comparative overview of immunogenic cell death signalling in animals and plants. Cell Death Differ 2023; 30:258-268. [PMID: 36195671 PMCID: PMC9950082 DOI: 10.1038/s41418-022-01060-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Revised: 08/29/2022] [Accepted: 09/06/2022] [Indexed: 11/05/2022] Open
Abstract
Host organisms utilise a range of genetically encoded cell death programmes in response to pathogen challenge. Host cell death can restrict pathogen proliferation by depleting their replicative niche and at the same time dying cells can alert neighbouring cells to prepare environmental conditions favouring future pathogen attacks. As expected, many pathogenic microbes have strategies to subvert host cell death to promote their virulence. The structural and lifestyle differences between animals and plants have been anticipated to shape very different host defence mechanisms. However, an emerging body of evidence indicates that several components of the host-pathogen interaction machinery are shared between the two major branches of eukaryotic life. Many proteins involved in cell death execution or cell death-associated immunity in plants and animals exert direct effects on endomembrane and loss of membrane integrity has been proposed to explain the potential immunogenicity of dying cells. In this review we aim to provide a comparative view on how cell death processes are linked to anti-microbial defence mechanisms in plants and animals and how pathogens interfere with these cell death programmes. In comparison to the several well-defined cell death programmes in animals, immunogenic cell death in plant defence is broadly defined as the hypersensitive response. Our comparative overview may help discerning whether specific types of immunogenic cell death exist in plants, and correspondingly, it may provide new hints for previously undiscovered cell death mechanism in animals.
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Affiliation(s)
- Takaki Maekawa
- Department of Biology, Institute for Plant Sciences, University of Cologne, 50674, Cologne, Germany.
- CEPLAS Cluster of Excellence on Plant Sciences at the University of Cologne, Cologne, Germany.
| | - Hamid Kashkar
- Faculty of Medicine and University Hospital of Cologne, Institute for Molecular Immunology, University of Cologne, 50931, Cologne, Germany.
- Faculty of Medicine and University Hospital of Cologne, Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931, Cologne, Germany.
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931, Cologne, Germany.
| | - Núria S Coll
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB, 08193, Bellaterra, Spain.
- Consejo Superior de Investigaciones Científicas (CSIC), 08001, Barcelona, Spain.
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Jeblick T, Leisen T, Steidele CE, Albert I, Müller J, Kaiser S, Mahler F, Sommer F, Keller S, Hückelhoven R, Hahn M, Scheuring D. Botrytis hypersensitive response inducing protein 1 triggers noncanonical PTI to induce plant cell death. PLANT PHYSIOLOGY 2023; 191:125-141. [PMID: 36222581 PMCID: PMC9806589 DOI: 10.1093/plphys/kiac476] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 09/20/2022] [Indexed: 05/28/2023]
Abstract
According to their lifestyle, plant pathogens are divided into biotrophic and necrotrophic organisms. Biotrophic pathogens exclusively nourish living host cells, whereas necrotrophic pathogens rapidly kill host cells and nourish cell walls and cell contents. To this end, the necrotrophic fungus Botrytis cinerea secretes large amounts of phytotoxic proteins and cell wall-degrading enzymes. However, the precise role of these proteins during infection is unknown. Here, we report on the identification and characterization of the previously unknown toxic protein hypersensitive response-inducing protein 1 (Hip1), which induces plant cell death. We found the adoption of a structurally conserved folded Alternaria alternata Alt a 1 protein structure to be a prerequisite for Hip1 to exert its necrosis-inducing activity in a host-specific manner. Localization and the induction of typical plant defense responses by Hip1 indicate recognition as a pathogen-associated molecular pattern at the plant plasma membrane. In contrast to other secreted toxic Botrytis proteins, the activity of Hip1 does not depend on the presence of the receptor-associated kinases BRI1-associated kinase 1 and suppressor of BIR1-1. Our results demonstrate that recognition of Hip1, even in the absence of obvious enzymatic or pore-forming activity, induces strong plant defense reactions eventually leading to plant cell death. Botrytis hip1 overexpression strains generated by CRISPR/Cas9 displayed enhanced infection, indicating the virulence-promoting potential of Hip1. Taken together, Hip1 induces a noncanonical defense response which might be a common feature of structurally conserved fungal proteins from the Alt a 1 family.
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Affiliation(s)
- Tanja Jeblick
- Plant Pathology, University of Kaiserslautern, Kaiserslautern 67663, Germany
| | - Thomas Leisen
- Plant Pathology, University of Kaiserslautern, Kaiserslautern 67663, Germany
| | - Christina E Steidele
- Phytopathology, TUM School of Life Sciences, Technical University of Munich, Freising 85354, Germany
| | - Isabell Albert
- Molecular Plant Physiology, FAU Erlangen, Erlangen 91058, Germany
| | - Jonas Müller
- Plant Pathology, University of Kaiserslautern, Kaiserslautern 67663, Germany
| | - Sabrina Kaiser
- Plant Pathology, University of Kaiserslautern, Kaiserslautern 67663, Germany
| | - Florian Mahler
- Molecular Biophysics, University of Kaiserslautern, Kaiserslautern 67663, Germany
| | - Frederik Sommer
- Molecular Biotechnology & Systems Biology, University of Kaiserslautern, Kaiserslautern 67663, Germany
| | - Sandro Keller
- Molecular Biophysics, University of Kaiserslautern, Kaiserslautern 67663, Germany
- Biophysics, Institute of Molecular Biosciences (IMB), NAWI Graz, University of Graz, Graz 8010, Austria
- Field of Excellence BioHealth, University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Ralph Hückelhoven
- Phytopathology, TUM School of Life Sciences, Technical University of Munich, Freising 85354, Germany
| | - Matthias Hahn
- Plant Pathology, University of Kaiserslautern, Kaiserslautern 67663, Germany
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Sun L, Qin J, Wu X, Zhang J, Zhang J. TOUCH 3 and CALMODULIN 1/4/6 cooperate with calcium-dependent protein kinases to trigger calcium-dependent activation of CAM-BINDING PROTEIN 60-LIKE G and regulate fungal resistance in plants. THE PLANT CELL 2022; 34:4088-4104. [PMID: 35863056 PMCID: PMC9516039 DOI: 10.1093/plcell/koac209] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 07/14/2022] [Indexed: 05/24/2023]
Abstract
Plants utilize localized cell-surface and intracellular receptors to sense microbes and activate the influx of calcium, which serves as an important second messenger in eukaryotes to regulate cellular responses. However, the mechanisms through which plants decipher calcium influx to activate immune responses remain largely unknown. Here, we show that pathogen-associated molecular patterns (PAMPs) trigger calcium-dependent phosphorylation of CAM-BINDING PROTEIN 60-LIKE G (CBP60g) in Arabidopsis (Arabidopsis thaliana). CALCIUM-DEPENDENT PROTEIN KINASE5 (CPK5) phosphorylates CBP60g directly, thereby enhancing its transcription factor activity. TOUCH 3 (TCH3) and its homologs CALMODULIN (CAM) 1/4/6 and CPK4/5/6/11 are required for PAMP-induced CBP60g phosphorylation. TCH3 interferes with the auto-inhibitory region of CPK5 and promotes CPK5-mediated CBP60g phosphorylation. Furthermore, CPKs-mediated CBP60g phosphorylation positively regulates plant resistance to soil-borne fungal pathogens. These lines of evidence uncover a novel calcium signal decoding mechanism during plant immunity through which TCH3 relieves auto-inhibition of CPK5 to phosphorylate and activate CBP60g. The findings reveal cooperative interconnections between different types of calcium sensors in eukaryotes.
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Affiliation(s)
- Lifan Sun
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jun Qin
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Xiaoyun Wu
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jinghan Zhang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- School of Life Sciences, Hebei University, Baoding, Hebei 710023, China
| | - Jie Zhang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China
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8
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Cai Z, Wang Z, Yue C, Sun A, Shen Y. Efficient expression and purification of soluble Harpin Ea protein by translation initiation region codon optimization. Protein Expr Purif 2021; 188:105970. [PMID: 34500070 DOI: 10.1016/j.pep.2021.105970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 08/31/2021] [Accepted: 09/05/2021] [Indexed: 11/19/2022]
Abstract
HarpinEa protein can stimulate plants to produce defense responses to resist the attack of pathogens, improve plant immune resistance, and promote plant growth. This has extremely high application value in agriculture. To efficiently express soluble HarpinEa protein, in this study, we expressed HarpinEa protein with a 6× His-tag in Escherichia coli BL21 (DE3). Because of the low level of expression of HarpinEa protein in E. coli, three rounds of synonymous codon optimization were performed on the +53 bp of the translation initiation region (TIR) of HarpinEa. Soluble HarpinEa protein after optimization accounted for 50.3% of the total soluble cellular protein expressed. After purification using a Ni Bestarose Fast Flow column, the purity of HarpinEa protein exceeded 95%, and the yield reached 227.5 mg/L of culture medium. The purified HarpinEa protein was sensitive to proteases and exhibited thermal stability. It triggered visible hypersensitive responses after being injected into tobacco leaves for 48 h. Plants treated with HarpinEa showed obvious growth-promoting and resistance-improving performance. Thus, the use of TIR synonymous codon optimization successfully achieved the economical, efficient, and soluble production of HarpinEa protein.
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Affiliation(s)
- Zengying Cai
- State Key Laboratory of Bioreactor Engineering, Newworld Institute of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China.
| | - Zhong Wang
- Shandong Shennong Ecological Technology Research Institute Co., Ltd., Shanghai Branch, Shanghai, 201114, China.
| | - Cheng Yue
- State Key Laboratory of Bioreactor Engineering, Newworld Institute of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China.
| | - Aiyou Sun
- State Key Laboratory of Bioreactor Engineering, Newworld Institute of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China.
| | - Yaling Shen
- State Key Laboratory of Bioreactor Engineering, Newworld Institute of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China.
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9
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Sun L, Zhang J. Regulatory role of receptor-like cytoplasmic kinases in early immune signaling events in plants. FEMS Microbiol Rev 2021; 44:845-856. [PMID: 32717059 DOI: 10.1093/femsre/fuaa035] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 07/25/2020] [Indexed: 12/22/2022] Open
Abstract
Receptor-like cytoplasmic kinases (RLCKs) play crucial roles in regulating plant development and immunity. Conserved pathogen-associated molecular patterns (PAMPs) derived from microbes are recognized by plant pattern recognition receptors to activate PAMP-triggered immunity (PTI). Microbial effectors, whose initial function is to promote virulence, are recognized by plant intracellular nucleotide-binding domain and leucine-rich repeat receptors (NLRs) to initiate effector-triggered immunity (ETI). Both PTI and ETI trigger early immune signaling events including the production of reactive oxygen species, induction of calcium influx and activation of mitogen-activated protein kinases. Research progress has revealed the important roles of RLCKs in the regulation of early PTI signaling. Accordingly, RLCKs are often targeted by microbial effectors that are evolved to evade PTI via diverse modulations. In some cases, modulation of RLCKs by microbial effectors triggers the activation of NLRs. This review covers the mechanisms by which RLCKs engage diverse substrates to regulate early PTI signaling and the regulatory roles of RLCKs in triggering NLR activation. Accumulating evidence suggests evolutionary links and close connections between PAMP- and effector-triggered early immune signaling that are mediated by RLCKs. As key immune regulators, RLCKs can be considered targets with broad prospects for the improvement of plant resistance via genetic engineering.
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Affiliation(s)
- Lifan Sun
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Beijing 100101, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Beijing 100049, China
| | - Jie Zhang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Beijing 100101, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Beijing 100049, China
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Inoue Y, Takikawa Y. Primers for specific detection and identification of Pseudomonas syringae pv. maculicola and P. cannabina pv. alisalensis. Appl Microbiol Biotechnol 2021; 105:1575-1584. [PMID: 33511445 DOI: 10.1007/s00253-021-11118-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/29/2020] [Accepted: 01/16/2021] [Indexed: 10/22/2022]
Abstract
Bacterial leaf spot and bacterial leaf blight are global threats to the cultivation of cruciferous vegetables, and it is necessary to develop methods to easily detect, identify, and distinguish the causative pathogens Pseudomonas syringae pv. maculicola (Psm) and P. cannabina pv. alisalensis (Pca). Here, we used the sequence specificity of the exchangeable effector loci flanking the hrp gene cluster to design primers that can help detect and discriminate between Psm and Pca. Primers common to both bacteria (hrpK_fw1 and hrpK_fw2) were designed within hrpK at the end of the hrp gene cluster. Psm-specific primers (MAC_rv1 and MAC_rv2) were designed in hopPtoB1 and Pca-specific primers (ALS_rv1 and ALS_rv2) were designed in hopX1 adjacent to hrpK. PCR using hrpK_fw1 and MAC_rv1 or hrpK_fw2 and MAC_rv2 amplified DNA fragments of only Psm, P. syringae pv. tomato (causal agent of tomato bacterial speck), and P. syringae pv. spinaciae (causal agent of spinach bacterial leaf spot), among 76 strains of phytopathogenic bacteria. PCR using hrpK_fw1 and ALS_rv1 or hrpK_2 and ALS_rv2 amplified DNA fragments of only Pca. Multiplex PCR with these primers could easily distinguish Psm and Pca from bacterial colonies isolated on growth media and detect the pathogen in symptomatic leaves. Multiplex nested PCR with the primers detected contamination in one Psm- and/or one Pca-infected seeds in 1000 seeds. These results suggest that these PCR primers could help detect and discriminate Psm and Pca. KEY POINTS: • We investigated Pseudomonas syringae pv. maculicola and P. cannabina pv. alisalensis. • Novel primers common to both bacteria were designed following genome comparison. • Multiplex PCR with new primers could discriminate Psm and Pca.
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Affiliation(s)
- Yasuhiro Inoue
- Central Region Agricultural Research Center, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan.
| | - Yuichi Takikawa
- Laboratory of Plant Pathology, Graduate School of Agriculture, and Graduate School of Science and Technology, Shizuoka University, Shizuoka, Shizuoka, Japan
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11
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Liu Y, Zhou X, Liu W, Miao W. The stability of the coiled-coil structure near to N-terminus influence the heat resistance of harpin proteins from Xanthomonas. BMC Microbiol 2020; 20:344. [PMID: 33183263 PMCID: PMC7663895 DOI: 10.1186/s12866-020-02029-6] [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: 08/26/2020] [Accepted: 11/01/2020] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Heat resistance is a common characteristic of harpins, a class of proteins found in Gram-negative bacteria, which may be related to the stability of coiled-coil (CC) structure. The CC structure is a ubiquitous protein folding and assembly motif made of α-helices wrapping around each other forming a supercoil. Specifically, whether the stability of the CC structure near to N-terminus of four selected harpin proteins from Xanthomonas (hereafter referred to as Hpa1) would influence their characteristics of heat resistance was investigated. We used bioinformatics approach to predict the structure of Hpa1, used the performance of hypersensitive response (HR)-induction activity of Hpa1 and circular dichroism (CD) spectral analyses to detect the relationship between the stability of the CC structure of Hpa1 and heat resistance. RESULTS Each of four-selected Hpa1 has two α-helical regions with one in their N-terminus that could form CC structure, and the other in their C-terminus that could not. And the important amino acid residues involved in the CC motifs are located on helices present on the surface of these proteins, indicating they may engage in the formation of oligo mericaggregates, which may be responsible for HR elicitation by harpins and their high thermal stability. Increased or decreased the probability of forming a CC could either induce a stronger HR response or eliminate the ability to induce HR in tobacco after high temperature treatment. In addition, although the four Hpa1 mutants had little effect on the induction of HR by Hpa1, its thermal stability was significantly decreased. The α-helical content increased with increasing temperature, and the secondary structures of Hpa1 became almost entirely α-helices when the temperature reached 200 °C. Moreover, the stability of the CC structure near to N-terminus was found to be positively correlated with the heat resistance of Hpa1. CONCLUSIONS The stability of the CC structure might sever as an inner drive for mediating the heat resistance of harpin proteins. Our results offer a new insight into the interpretation of the mechanism involved in the heat resistance of harpin protein and provide a theoretical basis for further harpin function investigations and structure modifications.
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Affiliation(s)
- Yue Liu
- College of Plant Protection, Hainan University, Haikou, Hainan Province, China
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou, Hainan Province, China
| | - Xiaoyun Zhou
- College of Plant Protection, Hainan University, Haikou, Hainan Province, China
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou, Hainan Province, China
| | - Wenbo Liu
- College of Plant Protection, Hainan University, Haikou, Hainan Province, China
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou, Hainan Province, China
| | - Weiguo Miao
- College of Plant Protection, Hainan University, Haikou, Hainan Province, China.
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou, Hainan Province, China.
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Phytopathogen Effectors Use Multiple Mechanisms to Manipulate Plant Autophagy. Cell Host Microbe 2020; 28:558-571.e6. [PMID: 32810441 DOI: 10.1016/j.chom.2020.07.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 04/23/2020] [Accepted: 07/20/2020] [Indexed: 01/10/2023]
Abstract
Autophagy is a central part of immunity and hence is a key target of pathogens. However, the precise molecular mechanisms by which plant pathogens manipulate autophagy remain elusive. We identify a network of 88 interactions between 184 effectors from bacterial, fungal, oomycete, and nematode pathogens with 25 Arabidopsis autophagy (ATG) proteins. Notably, Pseudomonas syringae pv tomato (Pto) bacterial effectors HrpZ1, HopF3, and AvrPtoB employ distinct molecular strategies to modulate autophagy. Calcium-dependent HrpZ1 oligomerization targets ATG4b-mediated cleavage of ATG8 to enhance autophagy, while HopF3 also targets ATG8 but suppresses autophagy, with both effectors promoting infection. AvrPtoB affects ATG1 kinase phosphorylation and enhances bacterial virulence. Since pathogens inject limited numbers of effectors into hosts, our findings establish autophagy as a key target during infection. Additionally, as autophagy is enhanced and inhibited by these effectors, autophagy likely has different functions throughout infection and, thus, must be temporally and precisely regulated for successful infection.
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Wang Y, Wang C, Rajaofera MJN, Zhu L, Liu W, Zheng F, Miao W. WY7 is a newly identified promoter from the rubber powdery mildew pathogen that regulates exogenous gene expression in both monocots and dicots. PLoS One 2020; 15:e0233911. [PMID: 32479550 PMCID: PMC7263610 DOI: 10.1371/journal.pone.0233911] [Citation(s) in RCA: 5] [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: 02/22/2020] [Accepted: 05/14/2020] [Indexed: 12/12/2022] Open
Abstract
Promoters are very important for transcriptional regulation and gene expression, and have become invaluable tools for genetic engineering. Owing to the characteristics of obligate biotrophs, molecular research into obligate biotrophic fungi is seriously lagging behind, and very few of their endogenous promoters have been developed. In this study, a WY7 fragment was predicted in the genome of Oidium heveae Steinmann using PromoterScan. Its promoter function was verified with transient transformations (Agrobacterium tumefaciens-mediated transformation, ATMT) in Nicotiana tabacum cv. Xanthi nc. The analysis of the transcription range showed that WY7 could regulate GUS expression in both monocots (Zea mays Linn and Oryza sativa L. spp. Japonica cv. Nipponbare) and dicots (N. tabacum and Hylocereus undulates Britt). The results of the quantitative detection showed that the GUS transient expression levels when regulated by WY7 was more than 11.7 times that of the CaMV 35S promoter in dicots (N. tabacum) and 5.13 times that of the ACT1 promoter in monocots (O. sativa). GUS staining was not detected in the T1 generation of the WY7-GUS transgenic N. tabacum. This showed that WY7 is an inducible promoter. The cis elements of WY7 were predicted using PlantCARE, and further experiments indicated that WY7 was a low temperature- and salt-inducible promoter. Soluble proteins produced by WY7-hpa1Xoo transgenic tobacco elicited hypersensitive responses (HR) in N. tabacum leaves. N. tabacum transformed with pBI121-WY7-hpa1Xoo exhibited enhanced resistance to the tobacco mosaic virus (TMV). The WY7 promoter has a lot of potential as a tool for plant genetic engineering. Further in-depth studies will help to better understand the transcriptional regulation mechanisms of O. heveae.
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Affiliation(s)
- Yi Wang
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Hainan University, Ministry of Education, Haikou, China
- College of Plant Protection, Hainan University, Haikou, China
| | - Chen Wang
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Hainan University, Ministry of Education, Haikou, China
- College of Plant Protection, Hainan University, Haikou, China
| | - Mamy Jayne Nelly Rajaofera
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Hainan University, Ministry of Education, Haikou, China
- College of Plant Protection, Hainan University, Haikou, China
| | - Li Zhu
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Hainan University, Ministry of Education, Haikou, China
- College of Plant Protection, Hainan University, Haikou, China
| | - Wenbo Liu
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Hainan University, Ministry of Education, Haikou, China
- College of Plant Protection, Hainan University, Haikou, China
| | - Fucong Zheng
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Hainan University, Ministry of Education, Haikou, China
- College of Plant Protection, Hainan University, Haikou, China
| | - Weiguo Miao
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Hainan University, Ministry of Education, Haikou, China
- College of Plant Protection, Hainan University, Haikou, China
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Wang D, Wang B, Wang J, Wang S, Wang W, Niu Y. Exogenous Application of Harpin Protein Hpa1 onto Pinellia ternata Induces Systemic Resistance Against Tobacco Mosaic Virus. PHYTOPATHOLOGY 2020; 110:1189-1198. [PMID: 32141384 DOI: 10.1094/phyto-12-19-0463-r] [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] [Indexed: 06/10/2023]
Abstract
The harpin protein Hpa1 has various beneficial effects in plants, such as promoting plant growth and inducing pathogen resistance. Our previous study found that Hpa1 could significantly alleviate the mosaic symptoms of tobacco mosaic virus (TMV) in Pinellia ternata, indicating that Hpa1 can effectively stimulate resistance. Here, the potential mechanism of disease resistance and field applicability of Hpa1 against TMV in P. ternata were further investigated. The results showed that 15 µg ml-1 Hpa1 had stronger antiviral activity than the control, and its protective effect was better than its curative effect. Furthermore, Hpa1 could significantly induce an increase in defense-related enzyme activity, including polyphenol oxidase, peroxidase, catalase, and superoxide dismutase, as well as increase the expression of disease resistance-related genes (PR1, PR3, PR5, and PDF1.2). Concurrently, Hpa1 significantly increased the content of some disease resistance-related substances, including hydrogen peroxide, phenolics, and callose, whereas the content of malondialdehyde was reduced. In addition, field application analysis demonstrated that Hpa1 could effectively elicit a defense response against TMV in P. ternata. Our findings propose a mechanism by which Hpa1 can prevent TMV infection in Pinellia by inducing systemic resistance, thereby providing an environmentally friendly approach for the use of Hpa1 in large-scale applications to improve TMV resistance in Pinellia.
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Affiliation(s)
- Defu Wang
- College of Life Sciences, Shanxi Agricultural University, Taigu 030801, Shanxi, China
| | - Baoxia Wang
- College of Life Sciences, Shanxi Agricultural University, Taigu 030801, Shanxi, China
| | - Jiangran Wang
- College of Life Sciences, Shanxi Agricultural University, Taigu 030801, Shanxi, China
| | - Shuting Wang
- College of Life Sciences, Shanxi Agricultural University, Taigu 030801, Shanxi, China
| | - Weiyu Wang
- Rongcheng Plant Protection Station, Rongcheng 264300, Shandong, China
| | - Yanbing Niu
- College of Life Sciences, Shanxi Agricultural University, Taigu 030801, Shanxi, China
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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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Li P, Zhang L, Mo X, Ji H, Bian H, Hu Y, Majid T, Long J, Pang H, Tao Y, Ma J, Dong H. Rice aquaporin PIP1;3 and harpin Hpa1 of bacterial blight pathogen cooperate in a type III effector translocation. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:3057-3073. [PMID: 30921464 PMCID: PMC6598099 DOI: 10.1093/jxb/erz130] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 03/12/2019] [Indexed: 05/20/2023]
Abstract
Varieties of Gram-negative bacterial pathogens infect their eukaryotic hosts by deploying the type III translocon to deliver effector proteins into the cytosol of eukaryotic cells in which effectors execute their pathological functions. The translocon is hypothetically assembled by bacterial translocators in association with the assumed receptors situated on eukaryotic plasma membranes. This hypothesis is partially verified in the present study with genetic, biochemical, and pathological evidence for the role of a rice aquaporin, plasma membrane intrinsic protein PIP1;3, in the cytosolic import of the transcription activator-like effector PthXo1 from the bacterial blight pathogen. PIP1;3 interacts with the bacterial translocator Hpa1 at rice plasma membranes to control PthXo1 translocation from cells of a well-characterized strain of the bacterial blight pathogen into the cytosol of cells of a susceptible rice variety. An extracellular loop sequence of PIP1;3 and the α-helix motif of Hpa1 determine both the molecular interaction and its consequences with respect to the effector translocation and the bacterial virulence on the susceptible rice variety. Overall, these results provide multiple experimental avenues to support the hypothesis that interactions between bacterial translocators and their interactors at the target membrane are essential for bacterial effector translocation.
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Affiliation(s)
- Ping Li
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu Province, China
| | - Liyuan Zhang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu Province, China
- Department of Plant Pathology, Shandong Agricultural University, Taian, Shandong Province, China
| | - Xuyan Mo
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu Province, China
| | - Hongtao Ji
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu Province, China
- Department of Biology, Jiangsu Formal University, Xuzhou, Jiangsu Province, China
| | - Huijie Bian
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu Province, China
| | - Yiqun Hu
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu Province, China
| | - Taha Majid
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu Province, China
| | - Juying Long
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu Province, China
| | - Hao Pang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu Province, China
| | - Yuan Tao
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu Province, China
| | - Jinbiao Ma
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu Province, China
| | - Hansong Dong
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu Province, China
- Department of Plant Pathology, Shandong Agricultural University, Taian, Shandong Province, China
- Correspondence:
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Zhou X, Liu Y, Huang J, Liu Q, Sun J, Cai X, Tang P, Liu W, Miao W. High temperatures affect the hypersensitive reaction, disease resistance and gene expression induced by a novel harpin HpaG-Xcm. Sci Rep 2019; 9:990. [PMID: 30700772 PMCID: PMC6353989 DOI: 10.1038/s41598-018-37886-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 12/07/2018] [Indexed: 11/29/2022] Open
Abstract
Harpin proteins are produced by plant-pathogenic Gram-negative bacteria and regulate bacterial pathogenicity by inducing plant growth and defence responses in non-hosts. HpaG-Xcm, a novel harpin protein, was identified from Xanthomonas citri pv. mangiferaeindicae, which causes bacterial black spot of mango. Here, we describe the predicted structure and functions of HpaG-Xcm and investigate the mechanism of heat resistance. The HpaG-Xcm amino acid sequence contains seven motifs and two α-helices, in the N- and C-terminals, respectively. The N-terminal α-helical region contains two heptads, which form the coiled-coil (CC) structure. The CC region, which is on the surface of HpaG-Xcm, forms oligomeric aggregates by forming hydrophobic interactions between hydrophobic amino acids. Like other harpins, HpaG-Xcm was heat stable, promoted root growth and induced a hypersensitive response (HR) and systemic acquired resistance in non-host plants. Subjecting HpaG-Xcm to high temperatures altered the gene expression induced by HpaG-Xcm in tobacco leaves, probably due to changes in the spatial structure of HpaG-Xcm. Phenotypic tests revealed that the high-temperature treatments reduced the HR and disease resistance induced by HpaG-Xcm but had little effect on growth promotion. These findings indicate that the stability of interactions between CC and plants may be associated with thermal stability of HpaG-Xcm.
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Affiliation(s)
- Xiaoyun Zhou
- Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, Hainan Province, China
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou, 570228, Hainan Province, China
| | - Yue Liu
- Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, Hainan Province, China
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou, 570228, Hainan Province, China
| | - Jiamin Huang
- Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, Hainan Province, China
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou, 570228, Hainan Province, China
| | - Qinghuan Liu
- Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, Hainan Province, China
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou, 570228, Hainan Province, China
| | - Jianzhang Sun
- Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, Hainan Province, China
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou, 570228, Hainan Province, China
| | - Xinfeng Cai
- Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, Hainan Province, China
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou, 570228, Hainan Province, China
| | - Peng Tang
- Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, Hainan Province, China
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou, 570228, Hainan Province, China
| | - Wenbo Liu
- Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, Hainan Province, China
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou, 570228, Hainan Province, China
| | - Weiguo Miao
- Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, Hainan Province, China.
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou, 570228, Hainan Province, China.
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18
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Miao W, Wang J. Genetic Transformation of Cotton with the Harpin-Encoding Gene hpa Xoo of Xanthomonas oryzae pv. oryzae and Evaluation of Resistance Against Verticillium Wilt. Methods Mol Biol 2019; 1902:257-280. [PMID: 30543078 DOI: 10.1007/978-1-4939-8952-2_22] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The soilborne fungal pathogen Verticillium dahliae Kleb causes Verticillium wilt in a wide range of crops including cotton (Gossypium hirsutum). To date, most upland cotton varieties are susceptible to V. dahliae, and the breeding for cotton varieties with the resistance to Verticillium wilt has not been successful. Hpa1Xoo is a harpin protein from Xanthomonas oryzae pv. oryzae which induces the hypersensitive cell death in plants. When hpa1Xoo was transformed into the susceptible cotton line Z35 through Agrobacterium-mediated transformation, the transgenic cotton line (T-34) with an improved resistance to Verticillium dahliae was obtained. Here, we describe the related research approach, such as Western blot, Southern blot, immuno-gold labeling, evaluation of resistance to Verticillium dahliae, and how to detect the micro-hypersensitive response and oxidative burst elicited by harpinXoo in plant tissue.
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Affiliation(s)
- Weiguo Miao
- College of Plant Protection, Hainan University, Haikou, People's Republic of China.
| | - Jingsheng Wang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, People's Republic of China
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19
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Cámara-Almirón J, Caro-Astorga J, de Vicente A, Romero D. Beyond the expected: the structural and functional diversity of bacterial amyloids. Crit Rev Microbiol 2018; 44:653-666. [PMID: 30354913 DOI: 10.1080/1040841x.2018.1491527] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Intense research has confirmed the formerly theoretical distribution of amyloids in nature, and studies on different systems have illustrated the role of these proteins in microbial adaptation and in interactions with the environment. Two lines of research are expanding our knowledge on functional amyloids: (i) structural studies providing insights into the molecular machineries responsible for the transition from monomer to fibers and (ii) studies showing the way in which these proteins might participate in the microbial fitness in natural settings. Much is known about how amyloids play a role in the social behavior of bacteria, or biofilm formation, and in the adhesion of bacteria to surfaces; however, we are still in the initial stages of understanding a complementary involvement of amyloids in bacteria-host interactions. This review will cover the following two topics: first, the key aspects of the microbial platforms dedicated to the assembly of the fibers, and second, the mechanisms by which bacteria utilize the morphological and biochemical variability of amyloids to modulate the immunological response of the host, plants and humans, contributing to (i) infection, in the case of pathogenic bacteria or (ii) promotion of the health of the host, in the case of beneficial bacteria.
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Affiliation(s)
- Jesús Cámara-Almirón
- a Instituto de Hortofruticultura Subtropical y Mediterránea ''La Mayora'' - Departamento de Microbiología , Universidad de Málaga , Málaga , Spain
| | - Joaquin Caro-Astorga
- a Instituto de Hortofruticultura Subtropical y Mediterránea ''La Mayora'' - Departamento de Microbiología , Universidad de Málaga , Málaga , Spain
| | - Antonio de Vicente
- a Instituto de Hortofruticultura Subtropical y Mediterránea ''La Mayora'' - Departamento de Microbiología , Universidad de Málaga , Málaga , Spain
| | - Diego Romero
- a Instituto de Hortofruticultura Subtropical y Mediterránea ''La Mayora'' - Departamento de Microbiología , Universidad de Málaga , Málaga , Spain
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Abstract
Bacterial pathogens cause plant diseases that threaten the global food supply. To control diseases, it is important to understand how pathogenic bacteria evade plant defense and promote infection. We identify from the phytopathogen Pseudomonas syringae a small-molecule virulence factor—phevamine A. Both the chemical structure and mode of action of phevamine A are different from known bacterial phytotoxins. Phevamine A promotes bacterial growth by suppressing plant immune responses, including both early (the generation of reactive oxygen species) and late (the deposition of cell wall reinforcing callose in leaves and leaf cell death) markers. This work uncovers a widely distributed, small-molecule virulence factor and shows the power of a multidisciplinary approach to identify small molecules important for plant infection. Bacterial plant pathogens cause significant crop damage worldwide. They invade plant cells by producing a variety of virulence factors, including small-molecule toxins and phytohormone mimics. Virulence of the model pathogen Pseudomonas syringae pv. tomato DC3000 (Pto) is regulated in part by the sigma factor HrpL. Our study of the HrpL regulon identified an uncharacterized, three-gene operon in Pto that is controlled by HrpL and related to the Erwinia hrp-associated systemic virulence (hsv) operon. Here, we demonstrate that the hsv operon contributes to the virulence of Pto on Arabidopsis thaliana and suppresses bacteria-induced immune responses. We show that the hsv-encoded enzymes in Pto synthesize a small molecule, phevamine A. This molecule consists of l-phenylalanine, l-valine, and a modified spermidine, and is different from known small molecules produced by phytopathogens. We show that phevamine A suppresses a potentiation effect of spermidine and l-arginine on the reactive oxygen species burst generated upon recognition of bacterial flagellin. The hsv operon is found in the genomes of divergent bacterial genera, including ∼37% of P. syringae genomes, suggesting that phevamine A is a widely distributed virulence factor in phytopathogens. Our work identifies a small-molecule virulence factor and reveals a mechanism by which bacterial pathogens overcome plant defense. This work highlights the power of omics approaches in identifying important small molecules in bacteria–host interactions.
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Lawaju BR, Lawrence KS, Lawrence GW, Klink VP. Harpin-inducible defense signaling components impair infection by the ascomycete Macrophomina phaseolina. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2018; 129:331-348. [PMID: 29936240 DOI: 10.1016/j.plaphy.2018.06.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 06/14/2018] [Accepted: 06/15/2018] [Indexed: 05/23/2023]
Abstract
Soybean (Glycine max) infection by the charcoal rot (CR) ascomycete Macrophomina phaseolina is enhanced by the soybean cyst nematode (SCN) Heterodera glycines. We hypothesized that G. max genetic lines impairing infection by M. phaseolina would also limit H. glycines parasitism, leading to resistance. As a part of this M. phaseolina resistance process, the genetic line would express defense genes already proven to impair nematode parasitism. Using G. max[DT97-4290/PI 642055], exhibiting partial resistance to M. phaseolina, experiments show the genetic line also impairs H. glycines parasitism. Furthermore, comparative studies show G. max[DT97-4290/PI 642055] exhibits induced expression of the effector triggered immunity (ETI) gene NON-RACE SPECIFIC DISEASE RESISTANCE 1/HARPIN INDUCED1 (NDR1/HIN1) that functions in defense to H. glycines as compared to the H. glycines and M. phaseolina susceptible line G. max[Williams 82/PI 518671]. Other defense genes that are induced in G. max[DT97-4290/PI 642055] include the pathogen associated molecular pattern (PAMP) triggered immunity (PTI) genes ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1), NONEXPRESSOR OF PR1 (NPR1) and TGA2. These observations link G. max defense processes that impede H. glycines parasitism to also potentially function toward impairing M. phaseolina pathogenicity. Testing this hypothesis, G. max[Williams 82/PI 518671] genetically engineered to experimentally induce GmNDR1-1, EDS1-2, NPR1-2 and TGA2-1 expression leads to impaired M. phaseolina pathogenicity. In contrast, G. max[DT97-4290/PI 642055] engineered to experimentally suppress the expression of GmNDR1-1, EDS1-2, NPR1-2 and TGA2-1 by RNA interference (RNAi) enhances M. phaseolina pathogenicity. The results show components of PTI and ETI impair both nematode and M. phaseolina pathogenicity.
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Affiliation(s)
- Bisho R Lawaju
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, College of Agriculture and Life Sciences, Mississippi State, MS, 39762, USA.
| | - Kathy S Lawrence
- Department of Entomology and Plant Pathology, Auburn University, 209 Life Science Building, Auburn, AL, 36849, USA.
| | - Gary W Lawrence
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, College of Agriculture and Life Sciences, Mississippi State University, Mississippi State, MS, 39762, USA.
| | - Vincent P Klink
- Department of Biological Sciences, College of Arts and Sciences, Mississippi State University, Mississippi State, MS, 39762, USA.
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Cao Y, Yang M, Ma W, Sun Y, Chen G. Overexpression of SSB Xoc, a Single-Stranded DNA-Binding Protein From Xanthomonas oryzae pv. oryzicola, Enhances Plant Growth and Disease and Salt Stress Tolerance in Transgenic Nicotiana benthamiana. FRONTIERS IN PLANT SCIENCE 2018; 9:953. [PMID: 30026748 PMCID: PMC6041465 DOI: 10.3389/fpls.2018.00953] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 06/13/2018] [Indexed: 05/05/2023]
Abstract
We previously reported that SSBXoc, a highly conserved single-stranded DNA-binding protein from Xanthomonas spp., was secreted through the type III secretion system (T3SS) and functioned as a harpin-like protein to elicit the hypersensitive response (HR) in the non-host plant, tobacco. In this study, we cloned SsbXoc gene from X. oryzae pv. oryzicola (Xoc), the causal agent of bacterial leaf streak in rice, and transferred it into Nicotiana benthamiana via Agrobacterium-mediated transformation. The expression of SsbXoc in transgenic N. benthamiana enhanced growth of both seedling and adult plants. When inoculated with the harpin Hpa1 or the pathogen Pseudomonas syringae pv. tomato DC3000 (Pst DC3000), the accumulation of reactive oxygen species (ROS) was increased more in SsbXoc transgenic lines than that in wild-type (WT) plants. The expression of pathogenesis-related protein genes (PR1a and SGT1), HR marker genes (HIN1 and HSR203J) and the mitogen-activated protein kinase pathway gene, MPK3, was significantly higher in transgenic lines than in WT after inoculation with Pst DC3000. In addition, SsbXoc transgenic lines showed the enhanced resistance to the pathogenic bacteria P. s. tabaci and the improved tolerance to salt stress, accompanied by the elevated transcription levels of the defense- and stress-related genes. Taken together, these results indicate that overexpression of the SsbXoc gene in N. benthamiana significantly enhanced plant growth and increased tolerance to disease and salt stress via modulating the expression of the related genes, thus providing an alternative approach for development of plants with improved tolerance against biotic and abiotic stresses.
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Affiliation(s)
- Yanyan Cao
- School of Agriculture and Biology, State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
| | - Mingtao Yang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, China
| | - Wenxiu Ma
- School of Agriculture and Biology, State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
| | - Yujing Sun
- School of Agriculture and Biology, State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
| | - Gongyou Chen
- School of Agriculture and Biology, State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
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Du Q, Yang X, Zhang J, Zhong X, Kim KS, Yang J, Xing G, Li X, Jiang Z, Li Q, Dong Y, Pan H. Over-expression of the Pseudomonas syringae harpin-encoding gene hrpZm confers enhanced tolerance to Phytophthora root and stem rot in transgenic soybean. Transgenic Res 2018; 27:277-288. [PMID: 29728957 DOI: 10.1007/s11248-018-0071-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 04/04/2018] [Indexed: 11/25/2022]
Abstract
Phytophthora root and stem rot (PRR) caused by Phytophthora sojae is one of the most devastating diseases reducing soybean (Glycine max) production all over the world. Harpin proteins in many plant pathogenic bacteria were confirmed to enhance disease and insect resistance in crop plants. Here, a harpin protein-encoding gene hrpZpsta from the P. syringae pv. tabaci strain Psta218 was codon-optimized (renamed hrpZm) and introduced into soybean cultivars Williams 82 and Shennong 9 by Agrobacterium-mediated transformation. Three independent transgenic lines over-expressing hrpZm were obtained and exhibited stable and enhanced tolerance to P. sojae infection in T2-T4 generations compared to the non-transformed (NT) and empty vector (EV)-transformed plants. Quantitative real-time PCR (qRT-PCR) analysis revealed that the expression of salicylic acid-dependent genes PR1, PR12, and PAL, jasmonic acid-dependent gene PPO, and hypersensitive response (HR)-related genes GmNPR1 and RAR was significantly up-regulated after P. sojae inoculation. Moreover, the activities of defense-related enzymes such as phenylalanine ammonia lyase (PAL), polyphenoloxidase (PPO), peroxidase, and superoxide dismutase also increased significantly in the transgenic lines compared to the NT and EV-transformed plants after inoculation. Our results suggest that over-expression of the hrpZm gene significantly enhances PRR tolerance in soybean by eliciting resistance responses mediated by multiple defense signaling pathways, thus providing an alternative approach for development of soybean varieties with improved tolerance against the soil-borne pathogen PRR.
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Affiliation(s)
- Qian Du
- College of Plant Science, Jilin University, Changchun, 130062, China
- Jilin Academy of Agricultural Sciences, Changchun, 130033, China
| | - Xiangdong Yang
- Jilin Academy of Agricultural Sciences, Changchun, 130033, China
| | - Jinhua Zhang
- Jilin Academy of Agricultural Sciences, Changchun, 130033, China
| | - Xiaofang Zhong
- Jilin Academy of Agricultural Sciences, Changchun, 130033, China
| | | | - Jing Yang
- Jilin Academy of Agricultural Sciences, Changchun, 130033, China
| | - Guojie Xing
- Jilin Academy of Agricultural Sciences, Changchun, 130033, China
| | - Xiaoyu Li
- Jilin Academy of Agricultural Sciences, Changchun, 130033, China
| | - Zhaoyuan Jiang
- Jilin Academy of Agricultural Sciences, Changchun, 130033, China
| | - Qiyun Li
- Jilin Academy of Agricultural Sciences, Changchun, 130033, China
| | - Yingshan Dong
- Jilin Academy of Agricultural Sciences, Changchun, 130033, China.
| | - Hongyu Pan
- College of Plant Science, Jilin University, Changchun, 130062, China.
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Firrao G, Torelli E, Polano C, Ferrante P, Ferrini F, Martini M, Marcelletti S, Scortichini M, Ermacora P. Genomic Structural Variations Affecting Virulence During Clonal Expansion of Pseudomonas syringae pv. actinidiae Biovar 3 in Europe. Front Microbiol 2018; 9:656. [PMID: 29675009 PMCID: PMC5895724 DOI: 10.3389/fmicb.2018.00656] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 03/20/2018] [Indexed: 11/13/2022] Open
Abstract
Pseudomonas syringae pv. actinidiae (Psa) biovar 3 caused pandemic bacterial canker of Actinidia chinensis and Actinidia deliciosa since 2008. In Europe, the disease spread rapidly in the kiwifruit cultivation areas from a single introduction. In this study, we investigated the genomic diversity of Psa biovar 3 strains during the primary clonal expansion in Europe using single molecule real-time (SMRT), Illumina and Sanger sequencing technologies. We recorded evidences of frequent mobilization and loss of transposon Tn6212, large chromosome inversions, and ectopic integration of IS sequences (remarkably ISPsy31, ISPsy36, and ISPsy37). While no phenotype change associated with Tn6212 mobilization could be detected, strains CRAFRU 12.29 and CRAFRU 12.50 did not elicit the hypersensitivity response (HR) on tobacco and eggplant leaves and were limited in their growth in kiwifruit leaves due to insertion of ISPsy31 and ISPsy36 in the hrpS and hrpR genes, respectively, interrupting the hrp cluster. Both strains had been isolated from symptomatic plants, suggesting coexistence of variant strains with reduced virulence together with virulent strains in mixed populations. The structural differences caused by rearrangements of self-genetic elements within European and New Zealand strains were comparable in number and type to those occurring among the European strains, in contrast with the significant difference in terms of nucleotide polymorphisms. We hypothesize a relaxation, during clonal expansion, of the selection limiting the accumulation of deleterious mutations associated with genome structural variation due to transposition of mobile elements. This consideration may be relevant when evaluating strategies to be adopted for epidemics management.
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Affiliation(s)
- Giuseppe Firrao
- Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Udine, Italy.,Istituto Nazionale Biostrutture e Biosistemi, Rome, Italy
| | - Emanuela Torelli
- Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Udine, Italy
| | - Cesare Polano
- Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Udine, Italy
| | - Patrizia Ferrante
- Council for Agricultural Research and Analysis of Agricultural Economics (CREA), Research Centre for Olive, Fruit Trees and Citrus, Rome, Italy
| | - Francesca Ferrini
- Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Udine, Italy
| | - Marta Martini
- Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Udine, Italy
| | - Simone Marcelletti
- Council for Agricultural Research and Analysis of Agricultural Economics (CREA), Research Centre for Olive, Fruit Trees and Citrus, Rome, Italy
| | - Marco Scortichini
- Council for Agricultural Research and Analysis of Agricultural Economics (CREA), Research Centre for Olive, Fruit Trees and Citrus, Rome, Italy
| | - Paolo Ermacora
- Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Udine, Italy
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Cao F, Xiong M, Li S, Cai H, Sun Y, Yang S, Liu X, Zhu R, Yu X, Wang X. Phosphatidylcholine absence affects the secretion of lipodepsipeptide phytoxins in Pseudomonas syringae pv. syringae van Hall CFCC 1336. Microbiol Res 2018; 206:113-120. [DOI: 10.1016/j.micres.2017.10.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 09/28/2017] [Accepted: 10/01/2017] [Indexed: 11/30/2022]
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Abstract
Plant pathogens such as fungi, oomycetes, viruses and bacteria infect important crops and account for significant economic losses worldwide. Therefore, it is critical to gain insights into plant-pathogen interactions at the cellular and molecular level. The outcome of the interaction between plants and pathogens greatly differs depending on the species, strains and cultivars involved as well as environmental factors, yet typically results in stress for the plant, the pathogen or both. These biotic-induced stresses can be monitored using a wide range of techniques, of which some of the most commonly used techniques are outlined in this chapter. One widely observed feature of biotic stress in plants is the generation of reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) and superoxide (O2-). We describe the quantification of hydrogen peroxide by 3,3'-diaminobenzidine (DAB) staining and luminol-based assays, and of superoxide by nitroblue tetrazolium (NBT) staining. Other techniques detailed here include measurement of callose deposition by aniline blue staining, evaluation of cell death by trypan blue staining and analysis of the loss of membrane integrity by monitoring electrolyte leakage.
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Affiliation(s)
| | - Gail M Preston
- Department of Plant Sciences, University of Oxford, Oxford, UK.
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Sun L, Qin J, Wang K, Zhang J. Expansion of pathogen recognition specificity in plants using pattern recognition receptors and artificially designed decoys. SCIENCE CHINA-LIFE SCIENCES 2017; 60:797-805. [DOI: 10.1007/s11427-017-9064-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Accepted: 04/03/2017] [Indexed: 10/19/2022]
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Hong Y, Yang Y, Zhang H, Huang L, Li D, Song F. Overexpression of MoSM1, encoding for an immunity-inducing protein from Magnaporthe oryzae, in rice confers broad-spectrum resistance against fungal and bacterial diseases. Sci Rep 2017; 7:41037. [PMID: 28106116 PMCID: PMC5247740 DOI: 10.1038/srep41037] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 12/15/2016] [Indexed: 12/27/2022] Open
Abstract
Potential of MoSM1, encoding for a cerato-platanin protein from Magnaporthe oryzae, in improvement of rice disease resistance was examined. Transient expression of MoSM1 in rice leaves initiated hypersensitive response and upregulated expression of defense genes. When transiently expressed in tobacco leaves, MoSM1 targeted to plasma membrane. The MoSM1-overexpressing (MoSM1-OE) transgenic rice lines showed an improved resistance, as revealed by the reduced disease severity and decreased in planta pathogen growth, against 2 strains belonging to two different races of M. oryzae, causing blast disease, and against 2 strains of Xanthomonas oryzae pv. oryzae, causing bacterial leaf blight disease. However, no alteration in resistance to sheath blight disease was observed in MoSM1-OE lines. The MoSM1-OE plants contained elevated levels of salicylic acid (SA) and jasmonic acid (JA) and constitutively activated the expression of SA and JA signaling-related regulatory and defense genes. Furthermore, the MoSM1-OE plants had no effect on drought and salt stress tolerance and on grain yield. We conclude that MoSM1 confers a broad-spectrum resistance against different pathogens through modulating SA- and JA-mediated signaling pathways without any penalty on abiotic stress tolerance and grain yield, providing a promising potential for application of MoSM1 in improvement of disease resistance in crops.
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Affiliation(s)
- Yongbo Hong
- National Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, P. R. China
| | - Yayun Yang
- National Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, P. R. China
| | - Huijuan Zhang
- National Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, P. R. China
| | - Lei Huang
- National Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, P. R. China
| | - Dayong Li
- National Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, P. R. China
| | - Fengming Song
- National Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, P. R. China
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Shi F, Dong Y, Zhang Y, Yang X, Qiu D. Overexpression of the PeaT1 Elicitor Gene from Alternaria tenuissima Improves Drought Tolerance in Rice Plants via Interaction with a Myo-Inositol Oxygenase. FRONTIERS IN PLANT SCIENCE 2017; 8:970. [PMID: 28649255 PMCID: PMC5465376 DOI: 10.3389/fpls.2017.00970] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 05/23/2017] [Indexed: 05/22/2023]
Abstract
Abiotic stresses, especially drought, seriously threaten cereal crops yields and quality. In this study, we observed that the rice plants of overexpression the Alternariatenuissima PeaT1 gene showed enhanced drought stress tolerance and increased the survival rate following a drought treatment. In PeaT1-overexpressing (PeaT1OE) plants, abscisic acid and chlorophyll content significantly increased, while the malondialdehyde (MDA) content decreased compared with the wild-type plants. Additionally, we confirmed that the transcript levels of drought-responsive genes, including OsAM1, OsLP2, and OsDST, were prominently lower in the PeaT1OE plants. In contrast, expression levels of genes encoding positive drought stress regulators including OsSKIPa, OsCPK9, OsNAC9, OSEREBP1, and OsTPKb were upregulated in PeaT1OE plants. Furthermore, combing the yeast two-hybrid assay, we found that PeaT1 could interact with amyo-inositol oxygenase (OsMIOX), which was verified by pull-down assay. Interestingly, OsMIOX was highly expressed in PeaT1OE plants during the drought treatment. Additionally, the OsMIOX-GFP fusion protein co-localized with the endoplasmic reticulum (ER) marker in tobacco protoplasts, suggesting OsMIOX performs its function in ER. Therefore, our results are useful for elucidating the molecular mechanism underlying the improvement of drought tolerance by PeaT1.
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Affiliation(s)
- Fachao Shi
- Key Laboratory for Biological Control of the Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural SciencesBeijing, China
- State Key Laboratory of Agrobiotechnology, China Agricultural UniversityBeijing, China
| | - Yijie Dong
- Key Laboratory for Biological Control of the Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural SciencesBeijing, China
| | - Yi Zhang
- Key Laboratory for Biological Control of the Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural SciencesBeijing, China
| | - Xiufeng Yang
- Key Laboratory for Biological Control of the Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural SciencesBeijing, China
| | - Dewen Qiu
- Key Laboratory for Biological Control of the Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural SciencesBeijing, China
- *Correspondence: Dewen Qiu,
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Dong Y, Li P, Zhang C. Harpin Hpa1 promotes flower development in Impatiens and Parochetus plants. BOTANICAL STUDIES 2016; 57:22. [PMID: 28597432 PMCID: PMC5430589 DOI: 10.1186/s40529-016-0132-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 06/29/2016] [Indexed: 05/27/2023]
Abstract
BACKGROUND The harpin protein Hpa1 has multiple beneficial effects in plants, promoting plant growth and development, increasing crop yield, and inducing plant resistance to pathogens and insect pests. In these effects, the 10-40 residue fragment (Hpa110-42) isolated from the Hpa1 sequence is 1.3 to 7.5-fold more effective than the full length. RESULTS This study extends the beneficial effects of Hpa1 and Hpa110-42 to flower development in three species of the garden balsam Impatiens and the garden scoparius Parochetus communis plant. The external application of Hpa1 or Hpa110-42 to the four ornamental plants had three effects, i.e., promoting flower growth, retarding senescence of fully expanded flowers, and increasing anthocyanin concentrations in those flowers and therefore improving their ornamental visages. Based on quantitative comparisons, Hpa110-42 was at least 17 and 42 % more effective than Hpa1 to increase anthocyanin concentrations and to promote the growth of flowers or delay their senescence. CONCLUSION Our results suggest that Hpa1 and especially Hpa110-42 have a great potential of horticultural application to increase ornamental merits of the different garden plants.
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Affiliation(s)
- Yilan Dong
- Nanjing Foreign Language School, 30 East Beijing Road, Nanjing, 210008 China
| | - Ping Li
- College of Plant Protection, Nanjing Agricultural University, 1 Weigang Town, Nanjing, 210095 China
| | - Chunling Zhang
- College of Plant Protection, Nanjing Agricultural University, 1 Weigang Town, Nanjing, 210095 China
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32
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Liu X, Long D, You H, Yang D, Zhou S, Zhang S, Li M, He M, Xiong M, Wang X. Phosphatidylcholine affects the secretion of the alkaline phosphatase PhoA in Pseudomonas strains. Microbiol Res 2016; 192:21-29. [DOI: 10.1016/j.micres.2016.02.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 01/05/2016] [Accepted: 02/01/2016] [Indexed: 01/13/2023]
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33
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Niehl A, Wyrsch I, Boller T, Heinlein M. Double-stranded RNAs induce a pattern-triggered immune signaling pathway in plants. THE NEW PHYTOLOGIST 2016; 211:1008-19. [PMID: 27030513 DOI: 10.1111/nph.13944] [Citation(s) in RCA: 133] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 02/24/2016] [Indexed: 05/20/2023]
Abstract
Pattern-triggered immunity (PTI) is a plant defense response that relies on the perception of conserved microbe- or pathogen-associated molecular patterns (MAMPs or PAMPs, respectively). Recently, it has been recognized that PTI restricts virus infection in plants; however, the nature of the viral or infection-induced PTI elicitors and the underlying signaling pathways are still unknown. As double-stranded RNAs (dsRNAs) are conserved molecular patterns associated with virus replication, we applied dsRNAs or synthetic dsRNA analogs to Arabidopsis thaliana and investigated PTI responses. We show that in vitro-generated dsRNAs, dsRNAs purified from virus-infected plants and the dsRNA analog polyinosinic-polycytidylic acid (poly(I:C)) induce typical PTI responses dependent on the co-receptor SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE 1 (SERK1), but independent of dicer-like (DCL) proteins in Arabidopsis. Moreover, dsRNA treatment of Arabidopsis induces SERK1-dependent antiviral resistance. Screening of Arabidopsis wild accessions demonstrates natural variability in dsRNA sensitivity. Our findings suggest that dsRNAs represent genuine PAMPs in plants, which induce a signaling cascade involving SERK1 and a specific dsRNA receptor. The dependence of dsRNA-mediated PTI on SERK1, but not on DCLs, implies that dsRNA-mediated PTI involves membrane-associated processes and operates independently of RNA silencing. dsRNA sensitivity may represent a useful trait to increase antiviral resistance in cultivated plants.
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Affiliation(s)
- Annette Niehl
- Botany, Department of Environmental Sciences, University of Basel, Basel, CH-4056, Switzerland
| | - Ines Wyrsch
- Botany, Department of Environmental Sciences, University of Basel, Basel, CH-4056, Switzerland
| | - Thomas Boller
- Botany, Department of Environmental Sciences, University of Basel, Basel, CH-4056, Switzerland
| | - Manfred Heinlein
- Botany, Department of Environmental Sciences, University of Basel, Basel, CH-4056, Switzerland
- Institut de Biologie Moléculaire des Plantes, CNRS UPR 2357, Strasbourg, 67000, France
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Díaz Tatis P, Zárate CA, Bernal Giraldo A, López Carrascal C. Infección de callo embriogénico friable de yuca con Xanthomonas axonopodis pv. manihotis (Xam). REVISTA COLOMBIANA DE BIOTECNOLOGÍA 2016. [DOI: 10.15446/rev.colomb.biote.v18n2.61523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Las nuevas tecnologías para la edición de genomas, como los TALEN y el sistema CRISPR/Cas9, representan una gran oportunidad para mejorar características deseables en diferentes organismos. Los TALEN son el resultado del acoplamiento de nucleasas a los TALE (Transcription Activator-Like Effectors), los cuales son efectores naturales de gran importancia en la patogénesis de las especies de Xanthomonas. Xanthomonas axonopodis pv. manihotis (Xam) es el agente causal del añublo bacteriano de la yuca, quien durante el proceso patogénico es capaz de translocar sus efectores a la célula vegetal mediante el sistema de secreción tipo tres (SSTT). Actualmente no hay protocolos estándar para la edición de genomas en yuca. En este estudio se exploró la posibilidad de translocar efectores sobre callo embriogénico friable (CEF) a través de la inoculación con Xam, con el fin de determinar el potencial de este patógeno como sistema de entrega de TALEN. El CEF de dos variedades de yuca susceptibles (COL2215 y cv. 60444) se cocultivaron con la cepa Xam668 a diferentes tiempos. Posteriormente, se evaluó la expresión de marcadores correspondientes a los genes blanco conocidos para los TALE presentes en esta cepa bacteriana. Aunque no se logró demostrar la translocación de los mismos en el tejido embriogénico, sí se lograron establecer condiciones adecuadas de cocultivo con Xam y el efecto que la infección bacteriana tiene sobre la regeneración de embriones a partir de este tejido. Palabras clave: cultivo de tejidos vegetales, edición de genomas, sistema de secreción tipo tres, efectores TALE, transformación.
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Ji H, Dong H. Key steps in type III secretion system (T3SS) towards translocon assembly with potential sensor at plant plasma membrane. MOLECULAR PLANT PATHOLOGY 2015; 16:762-73. [PMID: 25469869 PMCID: PMC6638502 DOI: 10.1111/mpp.12223] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Many plant- and animal-pathogenic Gram-negative bacteria employ the type III secretion system (T3SS) to translocate effector proteins from bacterial cells into the cytosol of eukaryotic host cells. The effector translocation occurs through an integral component of T3SS, the channel-like translocon, assembled by hydrophilic and hydrophobic proteinaceous translocators in a two-step process. In the first, hydrophilic translocators localize to the tip of a proteinaceous needle in animal pathogens, or a proteinaceous pilus in plant pathogens, and associate with hydrophobic translocators, which insert into host plasma membranes in the second step. However, the pilus needs to penetrate plant cell walls in advance. All hydrophilic translocators so far identified in plant pathogens are characteristic of harpins: T3SS accessory proteins containing a unitary hydrophilic domain or an additional enzymatic domain. Two-domain harpins carrying a pectate lyase domain potentially target plant cell walls and facilitate the penetration of the pectin-rich middle lamella by the bacterial pilus. One-domain harpins target plant plasma membranes and may play a crucial role in translocon assembly, which may also involve contrapuntal associations of hydrophobic translocators. In all cases, sensory components in the target plasma membrane are indispensable for the membrane recognition of translocators and the functionality of the translocon. The conjectural sensors point to membrane lipids and proteins, and a phosphatidic acid and an aquaporin are able to interact with selected harpin-type translocators. Interactions between translocators and their sensors at the target plasma membrane are assumed to be critical for translocon assembly.
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Affiliation(s)
- Hongtao Ji
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China
| | - Hansong Dong
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China
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Mehmood A, Abdallah K, Khandekar S, Zhurina D, Srivastava A, Al-Karablieh N, Alfaro-Espinoza G, Pletzer D, Ullrich MS. Expression of extra-cellular levansucrase in Pseudomonas syringae is controlled by the in planta fitness-promoting metabolic repressor HexR. BMC Microbiol 2015; 15:48. [PMID: 25886911 PMCID: PMC4357207 DOI: 10.1186/s12866-015-0349-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 01/15/2015] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Pseudomonas syringae pv. glycinea PG4180 causes bacterial blight on soybean plants and enters the leaf tissue through stomata or open wounds, where it encounters a sucrose-rich milieu. Sucrose is utilized by invading bacteria via the secreted enzyme, levansucrase (Lsc), liberating glucose and forming the polyfructan levan. P. syringae PG4180 possesses two functional lsc alleles transcribed at virulence-promoting low temperatures. RESULTS We hypothesized that transcription of lsc is controlled by the hexose metabolism repressor, HexR, since potential HexR binding sites were identified upstream of both lsc genes. A hexR mutant of PG4180 was significantly growth-impaired when incubated with sucrose or glucose as sole carbon source, but exhibited wild type growth when arabinose was provided. Analyses of lsc expression resulted in higher transcript and protein levels in the hexR mutant as compared to the wild type. The hexR mutant's ability to multiply in planta was reduced. HexR did not seem to impact hrp gene expression as evidenced by the hexR mutant's unaltered hypersensitive response in tobacco and its unmodified protein secretion pattern as compared to the wild type under hrp-inducing conditions. CONCLUSIONS Our data suggested a co-regulation of genes involved in extra-cellular sugar acquisition with those involved in intra-cellular energy-providing metabolic pathways in P. syringae.
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Affiliation(s)
- Amna Mehmood
- Molecular Life Science Research Center, Jacobs University Bremen, Campus Ring 1, Bremen, 28759, Germany.
| | - Khaled Abdallah
- Molecular Life Science Research Center, Jacobs University Bremen, Campus Ring 1, Bremen, 28759, Germany.
| | - Shaunak Khandekar
- Molecular Life Science Research Center, Jacobs University Bremen, Campus Ring 1, Bremen, 28759, Germany.
| | - Daria Zhurina
- Molecular Life Science Research Center, Jacobs University Bremen, Campus Ring 1, Bremen, 28759, Germany.
| | - Abhishek Srivastava
- Molecular Life Science Research Center, Jacobs University Bremen, Campus Ring 1, Bremen, 28759, Germany.
| | - Nehaya Al-Karablieh
- Molecular Life Science Research Center, Jacobs University Bremen, Campus Ring 1, Bremen, 28759, Germany.
- Hamdi Mango Center for Scientific Research, The University of Jordan, P.O. Box 13507, Amman, 11942, Jordan.
| | - Gabriela Alfaro-Espinoza
- Molecular Life Science Research Center, Jacobs University Bremen, Campus Ring 1, Bremen, 28759, Germany.
| | - Daniel Pletzer
- Molecular Life Science Research Center, Jacobs University Bremen, Campus Ring 1, Bremen, 28759, Germany.
| | - Matthias S Ullrich
- Molecular Life Science Research Center, Jacobs University Bremen, Campus Ring 1, Bremen, 28759, Germany.
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Liu P, Zhang W, Zhang LQ, Liu X, Wei HL. Supramolecular Structure and Functional Analysis of the Type III Secretion System in Pseudomonas fluorescens 2P24. FRONTIERS IN PLANT SCIENCE 2015; 6:1190. [PMID: 26779224 PMCID: PMC4700148 DOI: 10.3389/fpls.2015.01190] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Accepted: 12/11/2015] [Indexed: 05/14/2023]
Abstract
The type III secretion system (T3SS) of plant and animal bacterial pathogens directs the secretion and injection of proteins into host cells. Some homologous genes of T3SS were found also in non-pathogenic bacteria, but the organization of its machinery and basic function are still unknown. In this study, we identified a T3SS gene cluster from the plant growth-promoting Pseudomonas fluorescens 2P24 and isolated the corresponding T3SS apparatus. The T3SS gene cluster of strain 2P24 is similar organizationally to that of pathogenic P. syringae, except that it lacks the regulator hrpR and the hrpK1 and hrpH genes, which are involved in translocation of proteins. Electron microscopy revealed that the T3SS supramolecular structure of strain 2P24 was comprised of two distinctive substructures: a long extracellular, filamentous pilus, and a membrane-embedded base. We show that strain 2P24 deploys a harpin homolog protein, RspZ1, to elicit a hypersensitive response when infiltrated into Nicotiana tabacum cv. xanthi leaves with protein that is partially purified, and by complementing the hrpZ1 mutation of pHIR11. The T3SS of strain 2P24 retained ability to secrete effectors, whereas its effector translocation activity appeared to be excessively lost. Mutation of the rscC gene from 2P24 T3SS abolished the secretion of effectors, but the general biocontrol properties were unaffected. Remarkably, strain 2P24 induced functional MAMP-triggered immunity that included a burst of reactive oxygen species, strong suppression of challenge cell death, and disease expansion, while it was not associated with the secretion functional T3SS.
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Affiliation(s)
- Ping Liu
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of SciencesBeijing, China
| | - Wei Zhang
- Department of Plant Pathology, China Agricultural UniversityBeijing, China
- MOE Key Laboratory of Regional Energy and Environmental Systems Optimization, Resources and Environmental Research Academy, North China Electric Power UniversityBeijing, China
| | - Li-Qun Zhang
- Department of Plant Pathology, China Agricultural UniversityBeijing, China
| | - Xingzhong Liu
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of SciencesBeijing, China
| | - Hai-Lei Wei
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of SciencesBeijing, China
- *Correspondence: Hai-Lei Wei,
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Oligomerization, conformational stability and thermal unfolding of Harpin, HrpZPss and its hypersensitive response-inducing c-terminal fragment, C-214-HrpZPss. PLoS One 2014; 9:e109871. [PMID: 25502017 PMCID: PMC4264689 DOI: 10.1371/journal.pone.0109871] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 09/04/2014] [Indexed: 11/19/2022] Open
Abstract
HrpZ-a harpin from Pseudomonas syringae-is a highly thermostable protein that exhibits multifunctional abilities e.g., it elicits hypersensitive response (HR), enhances plant growth, acts as a virulence factor, and forms pores in plant plasma membranes as well as artificial membranes. However, the molecular mechanism of its biological activity and high thermal stability remained poorly understood. HR inducing abilities of non-overlapping short deletion mutants of harpins put further constraints on the ability to establish structure-activity relationships. We characterized HrpZPss from Pseudomonas syringae pv. syringae and its HR inducing C-terminal fragment with 214 amino acids (C-214-HrpZPss) using calorimetric, spectroscopic and microscopic approaches. Both C-214-HrpZPss and HrpZPss were found to form oligomers. We propose that leucine-zipper-like motifs may take part in the formation of oligomeric aggregates, and oligomerization could be related to HR elicitation. CD, DSC and fluorescence studies showed that the thermal unfolding of these proteins is complex and involves multiple steps. The comparable conformational stability at 25°C (∼10.0 kcal/mol) of HrpZPss and C-214-HrpZPss further suggest that their structures are flexible, and the flexibility allows them to adopt proper conformation for multifunctional abilities.
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Ger MJ, Louh GY, Lin YH, Feng TY, Huang HE. Ectopically expressed sweet pepper ferredoxin PFLP enhances disease resistance to Pectobacterium carotovorum subsp. carotovorum affected by harpin and protease-mediated hypersensitive response in Arabidopsis. MOLECULAR PLANT PATHOLOGY 2014; 15:892-906. [PMID: 24796566 PMCID: PMC6638834 DOI: 10.1111/mpp.12150] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Plant ferredoxin-like protein (PFLP) is a photosynthesis-type ferredoxin (Fd) found in sweet pepper. It contains an iron-sulphur cluster that receives and delivers electrons between enzymes involved in many fundamental metabolic processes. It has been demonstrated that transgenic plants overexpressing PFLP show a high resistance to many bacterial pathogens, although the mechanism remains unclear. In this investigation, the PFLP gene was transferred into Arabidopsis and its defective derivatives, such as npr1 (nonexpresser of pathogenesis-related gene 1) and eds1 (enhanced disease susceptibility 1) mutants and NAHG-transgenic plants. These transgenic plants were then infected with the soft-rot bacterial pathogen Pectobacterium carotovorum subsp. carotovorum (Erwinia carotovora ssp. carotovora, ECC) to investigate the mechanism behind PFLP-mediated resistance. The results revealed that, instead of showing soft-rot symptoms, ECC activated hypersensitive response (HR)-associated events, such as the accumulation of hydrogen peroxide (H2 O2 ), electrical conductivity leakage and expression of the HR marker genes (ATHSR2 and ATHSR3) in PFLP-transgenic Arabidopsis. This PFLP-mediated resistance could be abolished by inhibitors, such as diphenylene iodonium (DPI), 1-l-trans-epoxysuccinyl-leucylamido-(4-guanidino)-butane (E64) and benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (z-VAD-fmk), but not by myriocin and fumonisin. The PFLP-transgenic plants were resistant to ECC, but not to its harpin mutant strain ECCAC5082. In the npr1 mutant and NAHG-transgenic Arabidopsis, but not in the eds1 mutant, overexpression of the PFLP gene increased resistance to ECC. Based on these results, we suggest that transgenic Arabidopsis contains high levels of ectopic PFLP; this may lead to the recognition of the harpin and to the activation of the HR and other resistance mechanisms, and is dependent on the protease-mediated pathway.
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Affiliation(s)
- Mang-Jye Ger
- Department of Life Science, National University of Kaohsiung, Kaohsiung, 811, Taiwan
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Fu M, Xu M, Zhou T, Wang D, Tian S, Han L, Dong H, Zhang C. Transgenic expression of a functional fragment of harpin protein Hpa1 in wheat induces the phloem-based defence against English grain aphid. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:1439-53. [PMID: 24676030 PMCID: PMC3967084 DOI: 10.1093/jxb/ert488] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The harpin protein Hpa1 has multiple beneficial effects in plants, promoting plant growth and development, increasing crop yield, and inducing resistance to pathogens and insect pests. For these effects, the 10-40 residue fragment (Hpa1₁₀₋₄₂) isolated from the Hpa1 sequence is 1.3- to 7.5-fold more effective than the full-length protein. Here it is reported that the expression of Hpa1₁₀₋₄₂ under the direction of an insect-induced promoter induces the phloem-based defence to English grain aphid, a dominant species of wheat aphids. The expression of Hpa1₁₀₋₄₂ was found to compromise the colonization preference of aphids on the plant and further inhibit aphid reproduction in leaf colonies. In Hpa1₁₀₋₄₂-expressing wheat lines, moreover, aphid feeding from the phloem was repressed in correlation with the phloem-based defence. This defensive mechanism was shown as enhanced expression of wheat genes encoding phloem lectin proteins (PP2-A1 and PP2-A2) and β-1,3-glucan synthase-like enzymes (GSL2, GSL10, and GSL12). Both PP2-A and β-1,3-glucan formed high molecular mass polymers to block phloem sieve plate pores and therefore impede aphid feeding from the phloem. However, the phloem-based defence was impaired by treating plants with ethylene signalling inhibitors, suggesting the requirement for the ethylene signalling pathway. In addition, if Hpa1₁₀₋₄₂-expressing plants were subjected to attack by a small number of aphids, they newly acquired agriculturally beneficial characters, such as enhanced vegetative growth and increased tiller numbers and grain output values. These results suggest that the defensive and developmental roles of Hpa1₁₀₋₄₂ can be integrated into the germplasm of this agriculturally significant crop.
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Affiliation(s)
- Maoqiang Fu
- State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing Agricultural University, Nanjing, 210095, China
| | - Manyu Xu
- State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing Agricultural University, Nanjing, 210095, China
| | - Ting Zhou
- State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing Agricultural University, Nanjing, 210095, China
| | - Defu Wang
- State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing Agricultural University, Nanjing, 210095, China
| | - Shan Tian
- State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing Agricultural University, Nanjing, 210095, China
| | - Liping Han
- State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing Agricultural University, Nanjing, 210095, China
| | - Hansong Dong
- State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing Agricultural University, Nanjing, 210095, China
| | - Chunling Zhang
- State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing Agricultural University, Nanjing, 210095, China
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Li X, Han B, Xu M, Han L, Zhao Y, Liu Z, Dong H, Zhang C. Plant growth enhancement and associated physiological responses are coregulated by ethylene and gibberellin in response to harpin protein Hpa1. PLANTA 2014; 239:831-46. [PMID: 24395199 PMCID: PMC3955481 DOI: 10.1007/s00425-013-2013-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Accepted: 12/12/2013] [Indexed: 05/20/2023]
Abstract
The harpin protein Hpa1 produced by the bacterial blight pathogen of rice induces several growth-promoting responses in plants, activating the ethylene signaling pathway, increasing photosynthesis rates and EXPANSIN (EXP) gene expression levels, and thereby enhancing the vegetative growth. This study was attempted to analyze any mechanistic connections among the above and the role of gibberellin in these responses. Hpa1-induced growth enhancement was evaluated in Arabidopsis, tomato, and rice. And growth-promoting responses were determined mainly as an increase of chlorophyll a/b ratio, which indicates a potential elevation of photosynthesis rates, and enhancements of photosynthesis and EXP expression in the three plant species. In Arabidopsis, Hpa1-induced growth-promoting responses were partially compromised by a defect in ethylene perception or gibberellin biosynthesis. In tomato and rice, compromises of Hpa1-induced growth-promoting responses were caused by a pharmacological treatment with an ethylene perception inhibitor or a gibberellin biosynthesis inhibitor. In the three plant species, moreover, Hpa1-induced growth-promoting responses were significantly impaired, but not totally eliminated, by abolishing ethylene perception or gibberellin synthesis. However, simultaneous nullifications in both ethylene perception and gibberellin biosynthesis almost canceled the full effects of Hpa1 on plant growth, photosynthesis, and EXP2 expression. Theses results suggest that ethylene and gibberellin coregulate Hpa1-induced plant growth enhancement and associated physiological and molecular responses.
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Affiliation(s)
- Xiaojie Li
- State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing Agricultural University, Nanjing, 210095 China
- Tobacco Research Institute, Henan Provincial Academy of Agricultural Sciences, Xuchang, 461000 China
| | - Bing Han
- State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing Agricultural University, Nanjing, 210095 China
| | - Manyu Xu
- State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing Agricultural University, Nanjing, 210095 China
| | - Liping Han
- State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing Agricultural University, Nanjing, 210095 China
| | - Yanying Zhao
- State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing Agricultural University, Nanjing, 210095 China
| | - Zhilan Liu
- State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing Agricultural University, Nanjing, 210095 China
| | - Hansong Dong
- State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing Agricultural University, Nanjing, 210095 China
| | - Chunling Zhang
- State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing Agricultural University, Nanjing, 210095 China
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Xiong M, Long D, He H, Li Y, Li Y, Wang X. Phosphatidylcholine synthesis is essential for HrpZ harpin secretion in plant pathogenic Pseudomonas syringae and non-pathogenic Pseudomonas sp. 593. Microbiol Res 2014; 169:196-204. [PMID: 23886927 DOI: 10.1016/j.micres.2013.06.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 06/21/2013] [Accepted: 06/22/2013] [Indexed: 10/26/2022]
Abstract
Pseudomonas syringae pv. syringae van Hall is important phytopathogenic bacterium of stone fruit trees, and able to elicit hypersensitive response (HR) in nonhost plants. The HrpZ, secreted via type III secretion system (T3SS) to the extracellular space of the plant, is a T3SS-dependent protein and a sole T3SS effector able to induce the host defense response outside host cells. We deleted the phosphatidylcholine synthase gene (pcs) of P. syringae pv. syringae van Hall CFCC 1336, and found that the 1336 pcs(-) mutant was unable to synthesize phosphatidylcholine and elicit a typical HR in soybean. Further studies showed that the 1336 pcs(-) mutant was unable to secrete HrpZ harpin but could express HrpZ protein in cytoplasm as effectively as the wild type. To confirm if phosphatidylcholine affects HrpZ harpin secretion, we introduced the hrpZ gene into the soil-dwelling bacterium Pseudomonas sp. 593 and the 593 pcs(-) mutant, which were unable to express HrpZ harpin and elicit HR in tobacco or soybean. Western blotting and HR assay showed that the 593H not only secreted HrpZ harpin but also caused a strong HR in tobacco and soybean. In contrast, the 593 pcs(-)H only expressed HrpZ protein in its cytoplasm at the wild type level, but did not secrete HrpZ harpin or elicit HR reaction. Our results demonstrate that phosphatidylcholine is essential for the secretion of HrpZ harpin in P. syringae pv. syringae van Hall and other Pseudomonas strains.
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Affiliation(s)
- Min Xiong
- The Faculty of Life Science, Hubei University, China
| | - Deliang Long
- The Faculty of Life Science, Hubei University, China
| | - Huoguang He
- The Faculty of Life Science, Hubei University, China
| | - Yang Li
- The Faculty of Life Science, Hubei University, China
| | - Yadong Li
- The Faculty of Life Science, Hubei University, China
| | - Xingguo Wang
- The Faculty of Life Science, Hubei University, China.
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Vergne E, de Bernonville TD, Dupuis F, Sourice S, Cournol R, Berthelot P, Barny MA, Brisset MN, Chevreau E. Membrane-targeted HrpNEa can modulate apple defense gene expression. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2014; 27:125-35. [PMID: 24156770 DOI: 10.1094/mpmi-10-13-0305-r] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Fire blight caused by Erwinia amylovora is the major bacterial disease of tribe Maleae, including apple. Among the proteins secreted by this bacterium, HrpNEa, also called harpin, is known to induce hypersensitive response in nonhost plants and to form amyloid oligomers leading to pore opening in the plasma membrane and alteration of membrane homeostasis. To better understand the physiological effects of HrpNEa in the host plant, we produced transgenic apple plants expressing HrpNEa with or without a secretion signal peptide (SP). HrpNEa expressed with a SP was found to be associated within the membrane fraction, in accordance with amyloidogenic properties and the presence of transmembrane domains revealed by in silico analysis. Expression analysis of 28 apple defense-related genes revealed gene modulations in the transgenic line expressing membrane-targeted HrpNEa. While apple transgenic trees displaying a high constitutive expression level of SP-HrpNEa showed a slight reduction of infection frequency after E. amylovora inoculation, there was no decrease in the disease severity. Thus HrpNEa seems to act as an elicitor of host defenses, when localized in the host membrane.
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Yang L, Xu B, He W, Zhang L. The HrpW protein of Lonsdalea quercina N-5-1 has pectate lyase activity and is required for full bacterial virulence. J Basic Microbiol 2014; 54:1126-35. [PMID: 24395334 DOI: 10.1002/jobm.201300342] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 11/23/2013] [Indexed: 11/12/2022]
Abstract
Lonsdalea quercina N-5-1 is a bacterial pathogen that causes poplar bark cankers. It has been isolated from the branch of Populus × euramericana cv. "74/76" in Henan, China. Previous studies have revealed that the Type III secretion system (T3SS) acts as an essential pathogenic factor in L. quercina N-5-1. HrpW is a putative effector of T3SS in strain N-5-1, which has a typical harpin domain at the amino terminal and a pectate lyase (Pel) domain at its carboxyl terminal. Genetic evidence had shown that, compared to the wild-type and the complementary strain, the hrpW mutation causes a small but significant reduction in virulence when inoculated on the poplar branches. The amino terminal domain of HrpW was found to trigger tobacco hypersensitive response, but the carboxyl terminal domain of HrpW was not. Unlike most HrpW homologs in other bacteria, the carboxyl terminal domain of HrpW of strain N-5-1 exhibited detectable pectate lyase activity. Site-direction mutations (W104A, W171M) further demonstrated that two tryptophan residues were essential to its pectate lyase activity. The results of the present work suggest that HrpW in L. quercina N-5-1 possesses pectate lyase activity and acts as a nonessential but important pathogenic factor in poplar bark canker disease.
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Affiliation(s)
- Li Yang
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, Beijing Forestry University, Beijing, 100083, China
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Akram W, Mahboob A, Javed AA. Bacillus thuringiensis strain 199 can induce systemic resistance in tomato against Fusarium wilt. Eur J Microbiol Immunol (Bp) 2013; 3:275-80. [PMID: 24294498 PMCID: PMC3838544 DOI: 10.1556/eujmi.3.2013.4.7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 10/03/2013] [Accepted: 10/03/2013] [Indexed: 11/19/2022] Open
Abstract
The research work was performed to investigate the potential of Bacillus thuringiensis strain 199 to induce systemic resistance in tomato against Fusarium wilt. Roots of two-week-old seedlings of tomato plants were primed with bacterial strain. After 10 days of transplantation, some pots of tomato seedlings were provided with inoculum of Fusarium oxysporum lycopersici according to experimental design to induce disease. After 15 days of incubation period, plants challenged with F. oxysporum lycopersici alone were having obvious symptoms of Fusarium wilt. Plants that were treated with B. thuringiensis 199 + F. oxysporum lycopersici were having significant reduction of disease severity. Quantity of total phenolics increased 1.7-fold in bacterial-treated plants as compared to nontreated. Likewise, in case of defense-related enzymes, a significant increase of 1.3-, 1.8-, and 1.4-fold in polyphenol oxidase (PPO), phenyl ammonia lyase (PAL), and peroxidase (PO) was observed in comparison with untreated control. These results, hence, prove the potential of this bacterial strain for use as plant protection agent.
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Thermally stable harpin, HrpZPss is sensitive to chemical denaturants: Probing tryptophan environment, chemical and thermal unfolding by fluorescence spectroscopy. Biochimie 2013; 95:2437-44. [DOI: 10.1016/j.biochi.2013.09.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Accepted: 09/05/2013] [Indexed: 01/10/2023]
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Choi MS, Kim W, Lee C, Oh CS. Harpins, multifunctional proteins secreted by gram-negative plant-pathogenic bacteria. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2013; 26:1115-22. [PMID: 23745678 DOI: 10.1094/mpmi-02-13-0050-cr] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Harpins are glycine-rich and heat-stable proteins that are secreted through type III secretion system in gram-negative plant-pathogenic bacteria. Many studies show that these proteins are mostly targeted to the extracellular space of plant tissues, unlike bacterial effector proteins that act inside the plant cells. Over the two decades since the first harpin of pathogen origin, HrpN of Erwinia amylovora, was reported in 1992 as a cell-free elicitor of hypersensitive response (HR), diverse functional aspects of harpins have been determined. Some harpins were shown to have virulence activity, probably because of their involvement in the translocation of effector proteins into plant cytoplasm. Based on this function, harpins are now considered to be translocators. Their abilities of pore formation in the artificial membrane, binding to lipid components, and oligomerization are consistent with this idea. When harpins are applied to plants directly or expressed in plant cells, these proteins trigger diverse beneficial responses such as induction of defense responses against diverse pathogens and insects and enhancement of plant growth. Therefore, in this review, we will summarize the functions of harpins as virulence factors (or translocators) of bacterial pathogens, elicitors of HR and immune responses, and plant growth enhancers.
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Das SN, Madhuprakash J, Sarma PVSRN, Purushotham P, Suma K, Manjeet K, Rambabu S, Gueddari NEE, Moerschbacher BM, Podile AR. Biotechnological approaches for field applications of chitooligosaccharides (COS) to induce innate immunity in plants. Crit Rev Biotechnol 2013; 35:29-43. [PMID: 24020506 DOI: 10.3109/07388551.2013.798255] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Plants have evolved mechanisms to recognize a wide range of pathogen-derived molecules and to express induced resistance against pathogen attack. Exploitation of induced resistance, by application of novel bioactive elicitors, is an attractive alternative for crop protection. Chitooligosaccharide (COS) elicitors, released during plant fungal interactions, induce plant defenses upon recognition. Detailed analyses of structure/function relationships of bioactive chitosans as well as recent progress towards understanding the mechanism of COS sensing in plants through the identification and characterization of their cognate receptors have generated fresh impetus for approaches that would induce innate immunity in plants. These progresses combined with the application of chitin/chitosan/COS in disease management are reviewed here. In considering the field application of COS, however, efficient and large-scale production of desired COS is a challenging task. The available methods, including chemical or enzymatic hydrolysis and chemical or biotechnological synthesis to produce COS, are also reviewed.
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Affiliation(s)
- Subha Narayan Das
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad , Hyderabad , India and
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Bashir Z, Ahmad A, Shafique S, Anjum T, Shafique S, Akram W. Hypersensitive response - A biophysical phenomenon of producers. Eur J Microbiol Immunol (Bp) 2013; 3:105-10. [PMID: 24265926 DOI: 10.1556/eujmi.3.2013.2.3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2013] [Accepted: 03/05/2013] [Indexed: 01/24/2023] Open
Abstract
Hypersensitive response/reaction is a form of the cellular demise frequently linked alongside plant resistance against pathogen infection. Main transducers for this reaction are the intermediates of reactive oxygen and ion fluxes which are plausibly needed for hypersensitive response (Hpr Sen Rsp). An immediate and enormous energy production and its intra-cellular biochemical conduction are imperative for an Hpr Sen Rsp to be occurred. A number of studies proved that there are such diverse types of factors involved in triggering of Hpr Sen Rsp that morphologies of dead cells have become a vast topic of study. Hpr Sen Rsp could play a frolic role in plants as certain programmed cellular disintegrations in other organisms, to restrict pathogen growth. In fact, Hpr Sen Rsp can be involved in all types of tissues and most of the developmental stages.
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Misas-Villamil JC, Kolodziejek I, Crabill E, Kaschani F, Niessen S, Shindo T, Kaiser M, Alfano JR, van der Hoorn RAL. Pseudomonas syringae pv. syringae uses proteasome inhibitor syringolin A to colonize from wound infection sites. PLoS Pathog 2013; 9:e1003281. [PMID: 23555272 PMCID: PMC3610659 DOI: 10.1371/journal.ppat.1003281] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Accepted: 02/14/2013] [Indexed: 01/02/2023] Open
Abstract
Infection of plants by bacterial leaf pathogens at wound sites is common in nature. Plants defend wound sites to prevent pathogen invasion, but several pathogens can overcome spatial restriction and enter leaf tissues. The molecular mechanisms used by pathogens to suppress containment at wound infection sites are poorly understood. Here, we studied Pseudomonas syringae strains causing brown spot on bean and blossom blight on pear. These strains exist as epiphytes that can cause disease upon wounding caused by hail, sand storms and frost. We demonstrate that these strains overcome spatial restriction at wound sites by producing syringolin A (SylA), a small molecule proteasome inhibitor. Consequently, SylA-producing strains are able to escape from primary infection sites and colonize adjacent tissues along the vasculature. We found that SylA diffuses from the primary infection site and suppresses acquired resistance in adjacent tissues by blocking signaling by the stress hormone salicylic acid (SA). Thus, SylA diffusion creates a zone of SA-insensitive tissue that is prepared for subsequent colonization. In addition, SylA promotes bacterial motility and suppresses immune responses at the primary infection site. These local immune responses do not affect bacterial growth and were weak compared to effector-triggered immunity. Thus, SylA facilitates colonization from wounding sites by increasing bacterial motility and suppressing SA signaling in adjacent tissues.
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Affiliation(s)
| | - Izabella Kolodziejek
- Plant Chemetics Lab, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Emerson Crabill
- Center for Plant Science Innovation, University of Nebraska, Lincoln, Nebraska, United States of America
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Farnusch Kaschani
- Plant Chemetics Lab, Max Planck Institute for Plant Breeding Research, Cologne, Germany
- Chemical Biology Group, Department of Biology, University Duisburg-Essen, Essen, Germany
| | - Sherry Niessen
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Takayuki Shindo
- Plant Chemetics Lab, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Markus Kaiser
- Chemical Biology Group, Department of Biology, University Duisburg-Essen, Essen, Germany
| | - James R. Alfano
- Center for Plant Science Innovation, University of Nebraska, Lincoln, Nebraska, United States of America
- Department of Plant Pathology, University of Nebraska, Lincoln, Nebraska, United States of America
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