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Mei S, Song Y, Zhang Z, Cui H, Hou S, Miao W, Rong W. WRR4B contributes to a broad-spectrum disease resistance against powdery mildew in Arabidopsis. MOLECULAR PLANT PATHOLOGY 2024; 25:e13415. [PMID: 38279853 PMCID: PMC10777751 DOI: 10.1111/mpp.13415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 11/30/2023] [Accepted: 12/13/2023] [Indexed: 01/29/2024]
Abstract
Oidium heveae HN1106, a powdery mildew (PM) that infects rubber trees, has been found to trigger disease resistance in Arabidopsis thaliana through ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1)-, PHYTOALEXIN DEFICIENT 4 (PAD4)- and salicylic acid (SA)-mediated signalling pathways. In this study, a typical TOLL-INTERLEUKIN 1 RECEPTOR, NUCLEOTIDE-BINDING, LEUCINE-RICH REPEAT (TIR-NB-LRR)-encoding gene, WHITE RUST RESISTANCE 4 (WRR4B), was identified to be required for the resistance against O. heveae in Arabidopsis. The expression of WRR4B was upregulated by O. heveae inoculation, and WRR4B positively regulated the expression of genes involved in SA biosynthesis, such as EDS1, PAD4, ICS1 (ISOCHORISMATE SYNTHASE 1), SARD1 (SYSTEMIC-ACQUIRED RESISTANCE DEFICIENT 1) and CBP60g (CALMODULIN-BINDING PROTEIN 60 G). Furthermore, WRR4B triggered self-amplification, suggesting that WRR4B mediated plant resistance through taking part in the SA-based positive feedback loop. In addition, WRR4B induced an EDS1-dependent hypersensitive response in Nicotiana benthamiana and contributed to disease resistance against three other PM species: Podosphaera xanthii, Erysiphe quercicola and Erysiphe neolycopersici, indicating that WRR4B is a broad-spectrum disease resistance gene against PMs.
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Affiliation(s)
- Shuangshuang Mei
- College of Plant ProtectionHainan UniversityHaikouHainanChina
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and PestsHainan University, Ministry of EducationHaikouHainanChina
| | - Yuxin Song
- College of Plant ProtectionHainan UniversityHaikouHainanChina
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and PestsHainan University, Ministry of EducationHaikouHainanChina
| | - Zuer Zhang
- College of Plant ProtectionHainan UniversityHaikouHainanChina
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and PestsHainan University, Ministry of EducationHaikouHainanChina
| | - Haitao Cui
- Shandong Provincial Key Laboratory of Agricultural Microbiology, College of Plant ProtectionShandong Agricultural UniversityTai'anShandongChina
| | - Shuguo Hou
- Institute of Advanced Agricultural SciencesPeking UniversityWeifangShandongChina
| | - Weiguo Miao
- College of Plant ProtectionHainan UniversityHaikouHainanChina
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and PestsHainan University, Ministry of EducationHaikouHainanChina
| | - Wei Rong
- College of Plant ProtectionHainan UniversityHaikouHainanChina
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and PestsHainan University, Ministry of EducationHaikouHainanChina
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Derbyshire MC, Raffaele S. Surface frustration re-patterning underlies the structural landscape and evolvability of fungal orphan candidate effectors. Nat Commun 2023; 14:5244. [PMID: 37640704 PMCID: PMC10462633 DOI: 10.1038/s41467-023-40949-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 08/09/2023] [Indexed: 08/31/2023] Open
Abstract
Pathogens secrete effector proteins to subvert host physiology and cause disease. Effectors are engaged in a molecular arms race with the host resulting in conflicting evolutionary constraints to manipulate host cells without triggering immune responses. The molecular mechanisms allowing effectors to be at the same time robust and evolvable remain largely enigmatic. Here, we show that 62 conserved structure-related families encompass the majority of fungal orphan effector candidates in the Pezizomycotina subphylum. These effectors diversified through changes in patterns of thermodynamic frustration at surface residues. The underlying mutations tended to increase the robustness of the overall effector protein structure while switching potential binding interfaces. This mechanism could explain how conserved effector families maintained biological activity over long evolutionary timespans in different host environments and provides a model for the emergence of sequence-unrelated effector families with conserved structures.
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Affiliation(s)
- Mark C Derbyshire
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Perth, Australia
| | - Sylvain Raffaele
- Laboratoire des Interactions Plantes Micro-organismes Environnement (LIPME), INRAE, CNRS, Université de Toulouse, 31326, Castanet-Tolosan, France.
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McLellan H, Boevink PC, Birch PRJ. How to convert host plants into nonhosts. TRENDS IN PLANT SCIENCE 2023; 28:876-879. [PMID: 37270351 DOI: 10.1016/j.tplants.2023.05.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 05/14/2023] [Accepted: 05/15/2023] [Indexed: 06/05/2023]
Abstract
Recent research demonstrates that undermining interactions between pathogen effectors and their host target proteins can reduce infection. As more effector-target pairs are identified, their structures and interaction surfaces exposed, and there is the possibility of making multiple edits to diverse plant genomes, the desire to convert crops to nonhosts could become reality.
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Affiliation(s)
- Hazel McLellan
- Division of Plant Science, School of Life Sciences, University of Dundee, @James Hutton Institute, Errol Road, Invergowrie, Dundee DD2 5DA, UK
| | - Petra C Boevink
- Cell and Molecular Sciences, James Hutton Institute, Errol Road, Invergowrie, Dundee DD2 5DA, UK
| | - Paul R J Birch
- Division of Plant Science, School of Life Sciences, University of Dundee, @James Hutton Institute, Errol Road, Invergowrie, Dundee DD2 5DA, UK; Cell and Molecular Sciences, James Hutton Institute, Errol Road, Invergowrie, Dundee DD2 5DA, UK.
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Inoue Y, Phuong Vy TT, Singkaravanit-Ogawa S, Zhang R, Yamada K, Ogawa T, Ishizuka J, Narusaka Y, Takano Y. Selective deployment of virulence effectors correlates with host specificity in a fungal plant pathogen. THE NEW PHYTOLOGIST 2023; 238:1578-1592. [PMID: 36939621 DOI: 10.1111/nph.18790] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 01/27/2023] [Indexed: 06/18/2023]
Abstract
The hemibiotrophic fungal plant pathogen Colletotrichum orbiculare is predicted to secrete hundreds of effector proteins when the pathogen infects cucurbit crops, such as cucumber and melon, and tobacco (Nicotiana benthamiana), a distantly related Solanaceae species. Here, we report the identification of sets of C. orbiculare effector genes that are differentially required for fungal virulence to two phylogenetically distant host species. Through targeted gene knockout screening of C. orbiculare 'core' effector candidates defined based on in planta gene expression, we identified: four host-specific virulence effectors (named effector proteins for cucurbit infection, or EPCs) that are required for full virulence of C. orbiculare to cucurbit hosts, but not to the Solanaceae host N. benthamiana; and five host-nonspecific virulence effectors, which collectively contribute to fungal virulence to both hosts. During host infection, only a small subset of genes, including the host-specific EPC effector genes, showed preferential expression on one of the hosts, while gene expression profiles of the majority of other genes, including the five host-nonspecific effector genes, were common to both hosts. This work suggests that C. orbiculare adopts a host-specific effector deployment strategy, in addition to general host-blind virulence mechanisms, for adaptation to cucurbit hosts.
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Affiliation(s)
- Yoshihiro Inoue
- Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan
| | | | | | - Ru Zhang
- Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan
| | - Kohji Yamada
- Graduate School of Technology, Industrial and Social Sciences, Tokushima University, Tokushima, 770-8513, Japan
| | - Taiki Ogawa
- Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan
| | - Junya Ishizuka
- Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan
| | - Yoshihiro Narusaka
- Research Institute for Biological Sciences, Okayama Prefectural Technology Center for Agriculture, Forestry and Fisheries, Okayama, 716-1241, Japan
| | - Yoshitaka Takano
- Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan
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Verhoeven A, Finkers-Tomczak A, Prins P, Valkenburg-van Raaij DR, van Schaik CC, Overmars H, van Steenbrugge JJM, Tacken W, Varossieau K, Slootweg EJ, Kappers IF, Quentin M, Goverse A, Sterken MG, Smant G. The root-knot nematode effector MiMSP32 targets host 12-oxophytodienoate reductase 2 to regulate plant susceptibility. THE NEW PHYTOLOGIST 2023; 237:2360-2374. [PMID: 36457296 DOI: 10.1111/nph.18653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 11/23/2022] [Indexed: 06/17/2023]
Abstract
To establish persistent infections in host plants, herbivorous invaders, such as root-knot nematodes, must rely on effectors for suppressing damage-induced jasmonate-dependent host defenses. However, at present, the effector mechanisms targeting the biosynthesis of biologically active jasmonates to avoid adverse host responses are unknown. Using yeast two-hybrid, in planta co-immunoprecipitation, and mutant analyses, we identified 12-oxophytodienoate reductase 2 (OPR2) as an important host target of the stylet-secreted effector MiMSP32 of the root-knot nematode Meloidogyne incognita. MiMSP32 has no informative sequence similarities with other functionally annotated genes but was selected for the discovery of novel effector mechanisms based on evidence of positive, diversifying selection. OPR2 catalyzes the conversion of a derivative of 12-oxophytodienoate to jasmonic acid (JA) and operates parallel to 12-oxophytodienoate reductase 3 (OPR3), which controls the main pathway in the biosynthesis of jasmonates. We show that MiMSP32 targets OPR2 to promote parasitism of M. incognita in host plants independent of OPR3-mediated JA biosynthesis. Artificially manipulating the conversion of the 12-oxophytodienoate by OPRs increases susceptibility to multiple unrelated plant invaders. Our study is the first to shed light on a novel effector mechanism targeting this process to regulate the susceptibility of host plants.
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Affiliation(s)
- Ava Verhoeven
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
- Plant Stress Resilience, Utrecht University, Padualaan 8, 3584 CH, Utrecht, the Netherlands
- Plant-Environment Signaling, Utrecht University, Padualaan 8, 3584 CH, Utrecht, the Netherlands
| | - Anna Finkers-Tomczak
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
| | - Pjotr Prins
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
| | - Debbie R Valkenburg-van Raaij
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
| | - Casper C van Schaik
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
| | - Hein Overmars
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
| | - Joris J M van Steenbrugge
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
| | - Wannes Tacken
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
| | - Koen Varossieau
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
| | - Erik J Slootweg
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
| | - Iris F Kappers
- Laboratory of Plant Physiology, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
| | - Michaël Quentin
- INRAE, Université Côte d'Azur, CNRS, ISA, F-06903, Sophia Antipolis, France
| | - Aska Goverse
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
| | - Mark G Sterken
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
| | - Geert Smant
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
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Xia C, Qiu A, Wang M, Liu T, Chen W, Chen X. Current Status and Future Perspectives of Genomics Research in the Rust Fungi. Int J Mol Sci 2022; 23:ijms23179629. [PMID: 36077025 PMCID: PMC9456177 DOI: 10.3390/ijms23179629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 08/22/2022] [Accepted: 08/22/2022] [Indexed: 11/16/2022] Open
Abstract
Rust fungi in Pucciniales have caused destructive plant epidemics, have become more aggressive with new virulence, rapidly adapt to new environments, and continually threaten global agriculture. With the rapid advancement of genome sequencing technologies and data analysis tools, genomics research on many of the devastating rust fungi has generated unprecedented insights into various aspects of rust biology. In this review, we first present a summary of the main findings in the genomics of rust fungi related to variations in genome size and gene composition between and within species. Then we show how the genomics of rust fungi has promoted our understanding of the pathogen virulence and population dynamics. Even with great progress, many questions still need to be answered. Therefore, we introduce important perspectives with emphasis on the genome evolution and host adaptation of rust fungi. We believe that the comparative genomics and population genomics of rust fungi will provide a further understanding of the rapid evolution of virulence and will contribute to monitoring the population dynamics for disease management.
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Affiliation(s)
- Chongjing Xia
- Wheat Research Institute, School of Life Sciences and Engineering, Southwest University of Science and Technology, Mianyang 621010, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- Correspondence: (C.X.); (X.C.); Tel.: +86-13880134318 (C.X.); +1-509-335-8086 (X.C.)
| | - Age Qiu
- Wheat Research Institute, School of Life Sciences and Engineering, Southwest University of Science and Technology, Mianyang 621010, China
| | - Meinan Wang
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, USA
| | - Taiguo Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Wanquan Chen
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Xianming Chen
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, USA
- Wheat Health, Genetics, and Quality Research Unit, Agricultural Research Service, U.S. Department of Agriculture, Pullman, WA 99164-6430, USA
- Correspondence: (C.X.); (X.C.); Tel.: +86-13880134318 (C.X.); +1-509-335-8086 (X.C.)
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7
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Corredor-Moreno P, Badgami R, Jones S, Saunders DGO. Temporally coordinated expression of nuclear genes encoding chloroplast proteins in wheat promotes Puccinia striiformis f. sp. tritici infection. Commun Biol 2022; 5:853. [PMID: 35996019 PMCID: PMC9395331 DOI: 10.1038/s42003-022-03780-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 07/28/2022] [Indexed: 11/09/2022] Open
Abstract
Targeting host processes that allow pathogens to thrive can be invaluable in resistance breeding. Here, we generated a deep-sequencing transcriptome time course for Puccinia striiformis f. sp. tritici (Pst) infection on wheat and compared datasets from three wheat varieties with different levels of susceptibility to two tested pathogen isolates. We sought genes specifically altered in a susceptible host as candidates that might support colonisation. Host responses differed between Pst-varietal pairs most prominently early during infection. Notably, however, nuclear genes encoding chloroplast-localised proteins (NGCPs) exhibited temporal coordination of expression profiles that differed at later time points in relation to Pst susceptibility. Disrupting one such NGCP, encoding the chloroplast-localised RNA binding protein TaCSP41a, led to lower Pst susceptibility. These analyses thus highlight NGCPs as prime targets for Pst manipulation during infection and point to TaCSP41a disruption as a potential source of Pst resistance for breeding programmes. A transcriptome time course of Puccinia striiformis f. sp. tritici (Pst) infection reveals nuclear genes encoding chloroplast-localized proteins are manipulated during infection and highlights TaCSP41a disruption as a target for resistance breeding.
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Affiliation(s)
| | | | - Sally Jones
- John Innes Centre, Norwich Research Park, Norwich, UK
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Mohd Afandi NS, Habib MAH, Ismail MN. Recent insights on gene expression studies on Hevea Brasiliensis fatal leaf fall diseases. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2022; 28:471-484. [PMID: 35400887 PMCID: PMC8943083 DOI: 10.1007/s12298-022-01145-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 01/24/2022] [Accepted: 01/27/2022] [Indexed: 06/14/2023]
Abstract
Hevea brasiliensis is one of the most important agricultural commodities globally, heavily cultivated in Southeast Asia. Fatal leaf fall diseases cause aggressive leaf defoliation, linked to lower latex yield and death of crops before maturity. Due to the significant consequences of the disease to H. brasiliensis, the recent gene expression studies from four fall leaf diseases of H. brasiliensis were gathered; South American leaf blight, powdery mildew, Corynespora cassiicola and Phytophthora leaf fall disease. The differential analysis observed the pattern of commonly expressed genes upon fungi triggers using RT-PCR, DDRT-PCR, Real-time qRT-PCR and RNA-Seq. We have observed that RNA-Seq is the best tool to seek novel genes. Among the identified genes with defence-against fungi were pathogenesis-related genes such as β-1,3-glucanase and chitinase, the reactive oxygen species, and the phytoalexin biosynthesis. This manuscript also provided functional elaboration on the responsive genes and predicted possible biosynthetic pathways to identify and characterise novel genes in the future. At the end of the manuscript, the PCR methods and proteomic approaches were presented for future molecular and biochemical studies in the related diseases to H. brasiliensis.
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Affiliation(s)
- Nur Syafiqah Mohd Afandi
- Analytical Biochemistry Research Centre, Universiti Sains Malaysia, 11900 Bayan Lepas, Penang, Malaysia
| | - Mohd Afiq Hazlami Habib
- Analytical Biochemistry Research Centre, Universiti Sains Malaysia, 11900 Bayan Lepas, Penang, Malaysia
| | - Mohd Nazri Ismail
- Analytical Biochemistry Research Centre, Universiti Sains Malaysia, 11900 Bayan Lepas, Penang, Malaysia
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, 11800 USM Penang, Malaysia
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9
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Xu Z, Xiong D, Han Z, Tian C. A Putative Effector CcSp84 of Cytospora chrysosperma Localizes to the Plant Nucleus to Trigger Plant Immunity. Int J Mol Sci 2022; 23:1614. [PMID: 35163540 PMCID: PMC8835870 DOI: 10.3390/ijms23031614] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/27/2022] [Accepted: 01/28/2022] [Indexed: 02/04/2023] Open
Abstract
Cytospora chrysosperma is the main causal agent of poplar canker disease in China, especially in some areas with poor site conditions. Pathogens secrete a large number of effectors to interfere the plant immunity and promote their infection and colonization. Nevertheless, the roles of effectors in C. chrysosperma remain poorly understood. In this study, we identified and functionally characterized a candidate effector CcSp84 from C. chrysosperma, which contained a nuclear localization signal motif at the C-terminal and was highly induced during infection stages. Transient expression of CcSp84 in Nicotiana benthamiana leaves could trigger cell death. Additionally, deletion of CcSp84 significantly reduced fungal virulence to the polar twigs, while no obvious defects were observed in fungal growth and sensitivity to H2O2. Confocal microscopy revealed that CcSp84 labeled with a green fluorescent protein (GFP) was mainly accumulated in the plant nucleus. Further analysis revealed that the plant nucleus localization of CcSp84 was necessary to trigger plant immune responses, including ROS accumulation, callose deposition, and induced expression of jasmonic acid and ethylene defense-related genes. Collectively, our results suggest that CcSp84 is a virulence-related effector, and plant nucleus localization is required for its functions.
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Affiliation(s)
- Zhiye Xu
- Beijing Key Laboratory for Forest Pest Control, Beijing Forestry University, Beijing 100083, China; (Z.X.); (Z.H.)
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China
| | - Dianguang Xiong
- Beijing Key Laboratory for Forest Pest Control, Beijing Forestry University, Beijing 100083, China; (Z.X.); (Z.H.)
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China
| | - Zhu Han
- Beijing Key Laboratory for Forest Pest Control, Beijing Forestry University, Beijing 100083, China; (Z.X.); (Z.H.)
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China
| | - Chengming Tian
- Beijing Key Laboratory for Forest Pest Control, Beijing Forestry University, Beijing 100083, China; (Z.X.); (Z.H.)
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China
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10
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Figueroa M, Ortiz D, Henningsen EC. Tactics of host manipulation by intracellular effectors from plant pathogenic fungi. CURRENT OPINION IN PLANT BIOLOGY 2021; 62:102054. [PMID: 33992840 DOI: 10.1016/j.pbi.2021.102054] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 03/29/2021] [Accepted: 04/06/2021] [Indexed: 06/12/2023]
Abstract
Fungal pathogens can secrete hundreds of effectors, some of which are known to promote host susceptibility. This biological complexity, together with the lack of genetic tools in some fungi, presents a substantial challenge to develop a broad picture of the mechanisms these pathogens use for host manipulation. Nevertheless, recent advances in understanding individual effector functions are beginning to flesh out our view of fungal pathogenesis. This review discusses some of the latest findings that illustrate how effectors from diverse species use similar strategies to modulate plant physiology to their advantage. We also summarize recent breakthroughs in the identification of effectors from challenging systems, like obligate biotrophs, and emerging concepts such as the 'iceberg model' to explain how the activation of plant immunity can be turned off by effectors with suppressive activity.
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Affiliation(s)
- Melania Figueroa
- Commonwealth Scientific and Industrial Research Organisation, Agriculture and Food, Canberra, ACT 2601, Australia.
| | - Diana Ortiz
- National Research Institute for Agriculture, Food and Environment, Unit of Genetics and Breeding of Fruit and Vegetables, Domaine St Maurice, CS 60094, F-84143 Montfavet, France
| | - Eva C Henningsen
- Department of Plant Pathology, University of Minnesota, St. Paul, MN 55108, USA
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Han Z, Xiong D, Xu Z, Liu T, Tian C. The Cytospora chrysosperma Virulence Effector CcCAP1 Mainly Localizes to the Plant Nucleus To Suppress Plant Immune Responses. mSphere 2021; 6:e00883-20. [PMID: 33627507 PMCID: PMC8544888 DOI: 10.1128/msphere.00883-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 02/01/2021] [Indexed: 01/07/2023] Open
Abstract
Canker disease is caused by the fungus Cytospora chrysosperma and damages a wide range of woody plants, causing major losses to crops and native plants. Plant pathogens secrete virulence-related effectors into host cells during infection to regulate plant immunity and promote colonization. However, the functions of C. chrysosperma effectors remain largely unknown. In this study, we used Agrobacterium tumefaciens-mediated transient expression system in Nicotiana benthamiana and confocal microscopy to investigate the immunoregulation roles and subcellular localization of CcCAP1, a virulence-related effector identified in C. chrysosperma CcCAP1 was significantly induced in the early stages of infection and contains cysteine-rich secretory proteins, antigen 5, and pathogenesis-related 1 proteins (CAP) superfamily domain with four cysteines. CcCAP1 suppressed the programmed cell death triggered by Bcl-2-associated X protein (BAX) and the elicitin infestin1 (INF1) in transient expression assays with Nicotiana benthamiana The CAP superfamily domain was sufficient for its cell death-inhibiting activity and three of the four cysteines in the CAP superfamily domain were indispensable for its activity. Pathogen challenge assays in N. benthamiana demonstrated that transient expression of CcCAP1 promoted Botrytis cinerea infection and restricted reactive oxygen species accumulation, callose deposition, and defense-related gene expression. In addition, expression of green fluorescent protein-labeled CcCAP1 in N. benthamiana showed that it localized to both the plant nucleus and the cytoplasm, but the nuclear localization was essential for its full immune inhibiting activity. These results suggest that this virulence-related effector of C. chrysosperma modulates plant immunity and functions mainly via its nuclear localization and the CAP domain.IMPORTANCE The data presented in this study provide a key resource for understanding the biology and molecular basis of necrotrophic pathogen responses to Nicotiana benthamiana resistance utilizing effector proteins, and CcCAP1 may be used in future studies to understand effector-triggered susceptibility processes in the Cytospora chrysosperma-poplar interaction system.
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Affiliation(s)
- Zhu Han
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
| | - Dianguang Xiong
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
| | - Zhiye Xu
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
| | - Tingli Liu
- Provincial Key Laboratory of Agrobiology, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Chengming Tian
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
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12
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Dunker F, Oberkofler L, Lederer B, Trutzenberg A, Weiberg A. An Arabidopsis downy mildew non-RxLR effector suppresses induced plant cell death to promote biotroph infection. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:718-732. [PMID: 33063828 PMCID: PMC7853606 DOI: 10.1093/jxb/eraa472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 10/13/2020] [Indexed: 05/11/2023]
Abstract
Our understanding of obligate biotrophic pathogens is limited by lack of knowledge concerning the molecular function of virulence factors. We established Arabidopsis host-induced gene silencing (HIGS) to explore gene functions of Hyaloperonospora arabidopsidis, including CYSTEINE-RICH PROTEIN (HaCR)1, a potential secreted effector gene of this obligate biotrophic pathogen. HaCR1 HIGS resulted in H. arabidopsidis-induced local plant cell death and reduced pathogen reproduction. We functionally characterized HaCR1 by ectopic expression in Nicotiana benthamiana. HaCR1 was capable of inhibiting effector-triggered plant cell death. Consistent with this, HaCR1 expression in N. benthamiana led to stronger disease symptoms caused by the hemibiotrophic oomycete pathogen Phytophthora capsici, but reduced disease symptoms caused by the necrotrophic fungal pathogen Botrytis cinerea. Expressing HaCR1 in transgenic Arabidopsis confirmed higher susceptibility to H. arabidopsidis and to the bacterial hemibiotrophic pathogen Pseudomonas syringae. Increased H. arabidopsidis infection was in accordance with reduced PATHOGENESIS RELATED (PR)1 induction. Expression of full-length HaCR1 was required for its function, which was lost if the signal peptide was deleted, suggesting its site of action in the plant apoplast. This study provides phytopathological and molecular evidence for the importance of this widespread, but largely unexplored class of non-RxLR effectors in biotrophic oomycetes.
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Affiliation(s)
- Florian Dunker
- Faculty of Biology, Genetics, Biocenter Martinsried, LMU Munich, Planegg-Martinsried, Germany
| | - Lorenz Oberkofler
- Faculty of Biology, Genetics, Biocenter Martinsried, LMU Munich, Planegg-Martinsried, Germany
| | - Bernhard Lederer
- Faculty of Biology, Genetics, Biocenter Martinsried, LMU Munich, Planegg-Martinsried, Germany
| | - Adriana Trutzenberg
- Faculty of Biology, Genetics, Biocenter Martinsried, LMU Munich, Planegg-Martinsried, Germany
| | - Arne Weiberg
- Faculty of Biology, Genetics, Biocenter Martinsried, LMU Munich, Planegg-Martinsried, Germany
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13
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Adigun OA, Nadeem M, Pham TH, Jewell LE, Cheema M, Thomas R. Recent advances in bio-chemical, molecular and physiological aspects of membrane lipid derivatives in plant pathology. PLANT, CELL & ENVIRONMENT 2021; 44:1-16. [PMID: 33034375 DOI: 10.1111/pce.13904] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 09/22/2020] [Accepted: 09/30/2020] [Indexed: 06/11/2023]
Abstract
Plant pathogens pose a significant threat to the food industry and food security accounting for 10-40% crop losses annually on a global scale. Economic losses from plant diseases are estimated at $300B for major food crops and are associated with reduced food availability and accessibility and also high food costs. Although strategies exist to reduce the impact of diseases in plants, many of these introduce harmful chemicals to our food chain. Therefore, it is important to understand and utilize plants' immune systems to control plant pathogens to enable more sustainable agriculture. Lipids are core components of cell membranes and as such are part of the first line of defense against pathogen attack. Recent developments in omics technologies have advanced our understanding of how plant membrane lipid biosynthesis, remodelling and/or signalling modulate plant responses to infection. Currently, there is limited information available in the scientific literature concerning lipid signalling targets and their biochemical and physiological consequences in response to plant pathogens. This review focusses on the functions of membrane lipid derivatives and their involvement in plant responses to pathogens as biotic stressors. We describe major plant defense systems including systemic-acquired resistance, basal resistance, hypersensitivity and the gene-for-gene concept in this context.
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Affiliation(s)
- Oludoyin Adeseun Adigun
- School of Science and the Environment/Boreal Ecosystem Research Facility, Memorial University of Newfoundland, Corner Brook, Newfoundland and Labrador, A2H5G4, Canada
| | - Muhammad Nadeem
- School of Science and the Environment/Boreal Ecosystem Research Facility, Memorial University of Newfoundland, Corner Brook, Newfoundland and Labrador, A2H5G4, Canada
| | - Thu Huong Pham
- School of Science and the Environment/Boreal Ecosystem Research Facility, Memorial University of Newfoundland, Corner Brook, Newfoundland and Labrador, A2H5G4, Canada
| | - Linda Elizabeth Jewell
- St. John's Research and Development Centre, Agriculture and Agri-Food Canada, 204 Brookfield Rd, St. John's, Newfoundland and Labrador, A1E 6J5, Canada
| | - Mumtaz Cheema
- School of Science and the Environment/Boreal Ecosystem Research Facility, Memorial University of Newfoundland, Corner Brook, Newfoundland and Labrador, A2H5G4, Canada
| | - Raymond Thomas
- School of Science and the Environment/Boreal Ecosystem Research Facility, Memorial University of Newfoundland, Corner Brook, Newfoundland and Labrador, A2H5G4, Canada
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14
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Arroyo-Velez N, González-Fuente M, Peeters N, Lauber E, Noël LD. From effectors to effectomes: Are functional studies of individual effectors enough to decipher plant pathogen infectious strategies? PLoS Pathog 2020; 16:e1009059. [PMID: 33270803 PMCID: PMC7714205 DOI: 10.1371/journal.ppat.1009059] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Affiliation(s)
- Noe Arroyo-Velez
- LIPM, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | | | - Nemo Peeters
- LIPM, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | | | - Laurent D. Noël
- LIPM, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
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15
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Thordal-Christensen H. A holistic view on plant effector-triggered immunity presented as an iceberg model. Cell Mol Life Sci 2020; 77:3963-3976. [PMID: 32277261 PMCID: PMC7532969 DOI: 10.1007/s00018-020-03515-w] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 03/10/2020] [Accepted: 03/30/2020] [Indexed: 12/19/2022]
Abstract
The immune system of plants is highly complex. It involves pattern-triggered immunity (PTI), which is signaled and manifested through branched multi-step pathways. To counteract this, pathogen effectors target and inhibit individual PTI steps. This in turn can cause specific plant cytosolic nucleotide-binding leucine-rich repeat (NLR) receptors to activate effector-triggered immunity (ETI). Plants and pathogens have many genes encoding NLRs and effectors, respectively. Yet, only a few segregate genetically as resistance (R) genes and avirulence (Avr) effector genes in wild-type populations. In an attempt to explain this contradiction, a model is proposed where far most of the NLRs, the effectors and the effector targets keep one another in a silent state. In this so-called "iceberg model", a few NLR-effector combinations are genetically visible above the surface, while the vast majority is hidden below. Besides, addressing the existence of many NLRs and effectors, the model also helps to explain why individual downregulation of many effectors causes reduced virulence and why many lesion-mimic mutants are found. Finally, the iceberg model accommodates genuine plant susceptibility factors as potential effector targets.
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Affiliation(s)
- Hans Thordal-Christensen
- Department of Plant and Environmental Sciences, Copenhagen Plant Science Centre, University of Copenhagen, 1871, Frederiksberg C, Denmark.
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16
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Boevink PC, Birch PRJ, Turnbull D, Whisson SC. Devastating intimacy: the cell biology of plant-Phytophthora interactions. THE NEW PHYTOLOGIST 2020; 228:445-458. [PMID: 32394464 PMCID: PMC7540312 DOI: 10.1111/nph.16650] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 04/15/2020] [Indexed: 05/07/2023]
Abstract
An understanding of the cell biology underlying the burgeoning molecular genetic and genomic knowledge of oomycete pathogenicity is essential to gain the full context of how these pathogens cause disease on plants. An intense research focus on secreted Phytophthora effector proteins, especially those containing a conserved N-terminal RXLR motif, has meant that most cell biological studies into Phytophthora diseases have focussed on the effectors and their host target proteins. While these effector studies have provided novel insights into effector secretion and host defence mechanisms, there remain many unanswered questions about fundamental processes involved in spore biology, host penetration and haustorium formation and function.
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Affiliation(s)
- Petra C. Boevink
- Cell and Molecular SciencesJames Hutton InstituteErrol RoadInvergowrieDundeeDD2 5DAUK
| | - Paul R. J. Birch
- Cell and Molecular SciencesJames Hutton InstituteErrol RoadInvergowrieDundeeDD2 5DAUK
- Division of Plant SciencesUniversity of DundeeErrol RoadInvergowrieDundeeDD2 5DAUK
| | - Dionne Turnbull
- Division of Plant SciencesUniversity of DundeeErrol RoadInvergowrieDundeeDD2 5DAUK
| | - Stephen C. Whisson
- Cell and Molecular SciencesJames Hutton InstituteErrol RoadInvergowrieDundeeDD2 5DAUK
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17
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Nostadt R, Hilbert M, Nizam S, Rovenich H, Wawra S, Martin J, Küpper H, Mijovilovich A, Ursinus A, Langen G, Hartmann MD, Lupas AN, Zuccaro A. A secreted fungal histidine- and alanine-rich protein regulates metal ion homeostasis and oxidative stress. THE NEW PHYTOLOGIST 2020; 227:1174-1188. [PMID: 32285459 DOI: 10.1111/nph.16606] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 04/01/2020] [Indexed: 05/22/2023]
Abstract
Like pathogens, beneficial endophytic fungi secrete effector proteins to promote plant colonization, for example, through perturbation of host immunity. The genome of the root endophyte Serendipita indica encodes a novel family of highly similar, small alanine- and histidine-rich proteins, whose functions remain unknown. Members of this protein family carry an N-terminal signal peptide and a conserved C-terminal DELD motif. Here we report on the functional characterization of the plant-responsive DELD family protein Dld1 using a combination of structural, biochemical, biophysical and cytological analyses. The crystal structure of Dld1 shows an unusual, monomeric histidine zipper consisting of two antiparallel coiled-coil helices. Similar to other histidine-rich proteins, Dld1 displays varying affinity to different transition metal ions and undergoes metal ion- and pH-dependent unfolding. Transient expression of mCherry-tagged Dld1 in barley leaf and root tissue suggests that Dld1 localizes to the plant cell wall and accumulates at cell wall appositions during fungal penetration. Moreover, recombinant Dld1 enhances barley root colonization by S. indica, and inhibits H2 O2 -mediated radical polymerization of 3,3'-diaminobenzidine. Our data suggest that Dld1 has the potential to enhance micronutrient accessibility for the fungus and to interfere with oxidative stress and reactive oxygen species homeostasis to facilitate host colonization.
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Affiliation(s)
- Robin Nostadt
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Str. 10, 35043, Marburg, Germany
| | - Magdalena Hilbert
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Str. 10, 35043, Marburg, Germany
| | - Shadab Nizam
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Str. 10, 35043, Marburg, Germany
- Cluster of Excellence on Plant Sciences (CEPLAS), Cologne Biocenter, Botanical Institute, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - Hanna Rovenich
- Cluster of Excellence on Plant Sciences (CEPLAS), Cologne Biocenter, Botanical Institute, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - Stephan Wawra
- Cluster of Excellence on Plant Sciences (CEPLAS), Cologne Biocenter, Botanical Institute, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - Jörg Martin
- Max Planck Institute for Developmental Biology, Spemannstr. 35, 72076, Tübingen, Germany
| | - Hendrik Küpper
- Department of Plant Biophysics & Biochemistry, Biology Centre, Institute of Plant Molecular Biology, Czech Academy of Sciences, Branišovská 31/1160, 37005, České Budějovice, Czech Republic
- Department of Experimental Plant Biology, Faculty of Science, University of South Bohemia, Branišovská 31/1160, 37005, České Budějovice, Czech Republic
| | - Ana Mijovilovich
- Department of Plant Biophysics & Biochemistry, Biology Centre, Institute of Plant Molecular Biology, Czech Academy of Sciences, Branišovská 31/1160, 37005, České Budějovice, Czech Republic
| | - Astrid Ursinus
- Max Planck Institute for Developmental Biology, Spemannstr. 35, 72076, Tübingen, Germany
| | - Gregor Langen
- Cluster of Excellence on Plant Sciences (CEPLAS), Cologne Biocenter, Botanical Institute, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - Marcus D Hartmann
- Max Planck Institute for Developmental Biology, Spemannstr. 35, 72076, Tübingen, Germany
| | - Andrei N Lupas
- Max Planck Institute for Developmental Biology, Spemannstr. 35, 72076, Tübingen, Germany
| | - Alga Zuccaro
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Str. 10, 35043, Marburg, Germany
- Cluster of Excellence on Plant Sciences (CEPLAS), Cologne Biocenter, Botanical Institute, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
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18
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He Q, McLellan H, Boevink PC, Birch PR. All Roads Lead to Susceptibility: The Many Modes of Action of Fungal and Oomycete Intracellular Effectors. PLANT COMMUNICATIONS 2020; 1:100050. [PMID: 33367246 PMCID: PMC7748000 DOI: 10.1016/j.xplc.2020.100050] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 04/13/2020] [Accepted: 04/21/2020] [Indexed: 05/06/2023]
Abstract
The ability to secrete effector proteins that can enter plant cells and manipulate host processes is a key determinant of what makes a successful plant pathogen. Here, we review intracellular effectors from filamentous (fungal and oomycete) phytopathogens and the host proteins and processes that are targeted to promote disease. We cover contrasting virulence strategies and effector modes of action. Filamentous pathogen effectors alter the fates of host proteins that they target, changing their stability, their activity, their location, and the protein partners with which they interact. Some effectors inhibit target activity, whereas others enhance or utilize it, and some target multiple host proteins. We discuss the emerging topic of effectors that target negative regulators of immunity or other plant proteins with activities that support susceptibility. We also highlight the commonly targeted host proteins that are manipulated by effectors from multiple pathogens, including those representing different kingdoms of life.
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Affiliation(s)
- Qin He
- Key Laboratory of Horticultural Plant Biology (HZAU), Ministry of Education, Key Laboratory of Potato Biology and Biotechnology (HZAU), Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, Hubei 430070, China
- Division of Plant Sciences, School of Life Sciences, University of Dundee (at JHI), Invergowrie, Dundee DD2 5DA, UK
| | - Hazel McLellan
- Division of Plant Sciences, School of Life Sciences, University of Dundee (at JHI), Invergowrie, Dundee DD2 5DA, UK
| | - Petra C. Boevink
- Cell and Molecular Sciences, James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
| | - Paul R.J. Birch
- Division of Plant Sciences, School of Life Sciences, University of Dundee (at JHI), Invergowrie, Dundee DD2 5DA, UK
- Cell and Molecular Sciences, James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
- Corresponding author
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19
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Abstract
Many filamentous pathogens invade plant cells through specialized hyphae called haustoria. These infection structures are enveloped by a newly synthesized plant-derived membrane called the extrahaustorial membrane (EHM). This specialized membrane is the ultimate interface between the plant and pathogen, and is key to the success or failure of infection. Strikingly, the EHM is reminiscent of host-derived membrane interfaces that engulf intracellular metazoan parasites. These perimicrobial interfaces are critical sites where pathogens facilitate nutrient uptake and deploy virulence factors to disarm cellular defenses mounted by their hosts. Although the mechanisms underlying the biogenesis and functions of these host-microbe interfaces are poorly understood, recent studies have provided new insights into the cellular and molecular mechanisms involved. In this Cell Science at a Glance and the accompanying poster, we summarize these recent advances with a specific focus on the haustorial interfaces associated with filamentous plant pathogens. We highlight the progress in the field that fundamentally underpin this research topic. Furthermore, we relate our knowledge of plant-filamentous pathogen interfaces to those generated by other plant-associated organisms. Finally, we compare the similarities between host-pathogen interfaces in plants and animals, and emphasize the key questions in this research area.
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Affiliation(s)
- Tolga O Bozkurt
- Imperial College London, Department of Life Sciences, London, UK
| | - Sophien Kamoun
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
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20
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Harris MO, Pitzschke A. Plants make galls to accommodate foreigners: some are friends, most are foes. THE NEW PHYTOLOGIST 2020; 225:1852-1872. [PMID: 31774564 DOI: 10.1111/nph.16340] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Accepted: 07/24/2019] [Indexed: 06/10/2023]
Abstract
At the colonization site of a foreign entity, plant cells alter their trajectory of growth and development. The resulting structure - a plant gall - accommodates various needs of the foreigner, which are phylogenetically diverse: viruses, bacteria, protozoa, oomycetes, true fungi, parasitic plants, and many types of animals, including rotifers, nematodes, insects, and mites. The plant species that make galls also are diverse. We assume gall production costs the plant. All is well if the foreigner provides a gift that makes up for the cost. Nitrogen-fixing nodule-inducing bacteria provide nutritional services. Gall wasps pollinate fig trees. Unfortunately for plants, most galls are made for foes, some of which are deeply studied pathogens and pests: Agrobacterium tumefaciens, Rhodococcus fascians, Xanthomonas citri, Pseudomonas savastanoi, Pantoea agglomerans, 'Candidatus' phytoplasma, rust fungi, Ustilago smuts, root knot and cyst nematodes, and gall midges. Galls are an understudied phenomenon in plant developmental biology. We propose gall inception for discovering unifying features of the galls that plants make for friends and foes, talk about molecules that plants and gall-inducers use to get what they want from each other, raise the question of whether plants colonized by arbuscular mycorrhizal fungi respond in a gall-like manner, and present a research agenda.
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Affiliation(s)
- Marion O Harris
- Department of Entomology, North Dakota State University, Fargo, ND, 58014, USA
| | - Andrea Pitzschke
- Department of Biosciences, Salzburg University, Hellbrunner Strasse 34, A-5020, Salzburg, Austria
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21
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Alcântara A, Bosch J, Nazari F, Hoffmann G, Gallei M, Uhse S, Darino MA, Olukayode T, Reumann D, Baggaley L, Djamei A. Systematic Y2H Screening Reveals Extensive Effector-Complex Formation. FRONTIERS IN PLANT SCIENCE 2019; 10:1437. [PMID: 31803201 PMCID: PMC6872519 DOI: 10.3389/fpls.2019.01437] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 10/16/2019] [Indexed: 05/22/2023]
Abstract
During infection pathogens secrete small molecules, termed effectors, to manipulate and control the interaction with their specific hosts. Both the pathogen and the plant are under high selective pressure to rapidly adapt and co-evolve in what is usually referred to as molecular arms race. Components of the host's immune system form a network that processes information about molecules with a foreign origin and damage-associated signals, integrating them with developmental and abiotic cues to adapt the plant's responses. Both in the case of nucleotide-binding leucine-rich repeat receptors and leucine-rich repeat receptor kinases interaction networks have been extensively characterized. However, little is known on whether pathogenic effectors form complexes to overcome plant immunity and promote disease. Ustilago maydis, a biotrophic fungal pathogen that infects maize plants, produces effectors that target hubs in the immune network of the host cell. Here we assess the capability of U. maydis effector candidates to interact with each other, which may play a crucial role during the infection process. Using a systematic yeast-two-hybrid approach and based on a preliminary pooled screen, we selected 63 putative effectors for one-on-one matings with a library of nearly 300 effector candidates. We found that 126 of these effector candidates interacted either with themselves or other predicted effectors. Although the functional relevance of the observed interactions remains elusive, we propose that the observed abundance in complex formation between effectors adds an additional level of complexity to effector research and should be taken into consideration when studying effector evolution and function. Based on this fundamental finding, we suggest various scenarios which could evolutionarily drive the formation and stabilization of an effector interactome.
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Affiliation(s)
- André Alcântara
- Gregor Mendel Institute of Molecular Plant Biology, Vienna, Austria
| | - Jason Bosch
- Gregor Mendel Institute of Molecular Plant Biology, Vienna, Austria
| | - Fahimeh Nazari
- Gregor Mendel Institute of Molecular Plant Biology, Vienna, Austria
- Iranian Research Institute of Plant Protection, Tehran, Iran
| | - Gesa Hoffmann
- Gregor Mendel Institute of Molecular Plant Biology, Vienna, Austria
- Department of Plant Biology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Michelle Gallei
- Gregor Mendel Institute of Molecular Plant Biology, Vienna, Austria
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Simon Uhse
- Gregor Mendel Institute of Molecular Plant Biology, Vienna, Austria
| | - Martin A. Darino
- Gregor Mendel Institute of Molecular Plant Biology, Vienna, Austria
| | - Toluwase Olukayode
- Gregor Mendel Institute of Molecular Plant Biology, Vienna, Austria
- Global Institute for Food Security, University of Saskatchewan, Saskatoon, SK, Canada
| | - Daniel Reumann
- Gregor Mendel Institute of Molecular Plant Biology, Vienna, Austria
- Institute of Molecular Biotechnology, Vienna, Austria
| | - Laura Baggaley
- Gregor Mendel Institute of Molecular Plant Biology, Vienna, Austria
- Biotic Interactions and Crop Protection, Rothamsted Research, Harpenden, United Kingdom
| | - Armin Djamei
- Gregor Mendel Institute of Molecular Plant Biology, Vienna, Austria
- Department of Breeding Research, Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung (IPK), Gatersleben, Germany
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22
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Sharma G, Aminedi R, Saxena D, Gupta A, Banerjee P, Jain D, Chandran D. Effector mining from the Erysiphe pisi haustorial transcriptome identifies novel candidates involved in pea powdery mildew pathogenesis. MOLECULAR PLANT PATHOLOGY 2019; 20:1506-1522. [PMID: 31603276 PMCID: PMC6804345 DOI: 10.1111/mpp.12862] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Pea powdery mildew (PM) is an important fungal disease caused by an obligate biotroph, Erysiphe pisi (Ep), which significantly impacts pea production worldwide. The phytopathogen secretes a plethora of effectors, primarily through specialized infection structures termed haustoria, to establish a dynamic relationship with its host. To identify Ep effector candidates, a cDNA library of enriched haustoria from Ep-infected pea leaves was sequenced. The Ep transcriptome encodes 622 Ep candidate secreted proteins (CSPs), of which 167 were predicted to be candidate secreted effector proteins (CSEPs). Phylogenetic analysis indicates that Ep CSEPs are highly diverse, but, unlike cereal PM CSEPs, exhibit extensive sequence similarity with effectors from other PMs. Quantitative real-time PCR of a subset of EpCSEP/CSPs revealed that the majority are preferentially expressed in haustoria and exhibit infection stage-specific expression patterns. The functional roles of EpCSEP001, EpCSEP009 and EpCSP083 were probed by host-induced gene silencing (HIGS) via a double-stranded (ds) RNA-mediated RNAi approach. Foliar application of individual EpCSEP/CSP dsRNAs resulted in a marked reduction in PM disease symptoms. These findings were consistent with microscopic and molecular studies, suggesting that these Ep CSEP/CSPs play important roles in pea PM pathogenesis. Homology modelling revealed that EpCSEP001 and EpCSEP009 are analogous to fungal ribonucleases and belong to the RALPH family of effectors. This is the first study to identify and functionally validate candidate effectors from the agriculturally relevant pea PM, and highlights the utility of transcriptomics and HIGS to elucidate the key proteins associated with Ep pathogenesis.
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Affiliation(s)
- Gunjan Sharma
- Laboratory of Plant–Microbe InteractionsRegional Centre for BiotechnologyNCR Biotech Science ClusterFaridabadHaryanaIndia
| | - Raghavendra Aminedi
- Laboratory of Plant–Microbe InteractionsRegional Centre for BiotechnologyNCR Biotech Science ClusterFaridabadHaryanaIndia
| | - Divya Saxena
- Laboratory of Plant–Microbe InteractionsRegional Centre for BiotechnologyNCR Biotech Science ClusterFaridabadHaryanaIndia
- School of Computational and Integrative SciencesJawaharlal Nehru UniversityNew DelhiIndia
| | - Arunima Gupta
- Laboratory of Plant–Microbe InteractionsRegional Centre for BiotechnologyNCR Biotech Science ClusterFaridabadHaryanaIndia
| | - Priyajit Banerjee
- Transcription Regulation Lab, Regional Centre for BiotechnologyNCR Biotech Science ClusterFaridabadHaryanaIndia
- Kalinga Institute of Industrial TechnologyBhubaneswarOrissaIndia
| | - Deepti Jain
- Transcription Regulation Lab, Regional Centre for BiotechnologyNCR Biotech Science ClusterFaridabadHaryanaIndia
| | - Divya Chandran
- Laboratory of Plant–Microbe InteractionsRegional Centre for BiotechnologyNCR Biotech Science ClusterFaridabadHaryanaIndia
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23
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Thines M. An evolutionary framework for host shifts - jumping ships for survival. THE NEW PHYTOLOGIST 2019; 224:605-617. [PMID: 31381166 DOI: 10.1111/nph.16092] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 07/04/2019] [Indexed: 06/10/2023]
Abstract
Host jumping is a process by which pathogens settle in new host groups. It is a cornerstone in the evolution of pathogens, as it leads to pathogen diversification. It is unsurprising that host jumping is observed in facultative pathogens, as they can reproduce even if they kill their hosts. However, host jumps were thought to be rare in obligate biotrophic pathogens, but molecular phylogenetics has revealed that the opposite is true. Here, I review some concepts and recent findings and present several hypotheses on the matter. In short, pathogens evolve and diversify via host jumps, followed by radiation, specialisation and speciation. Host jumps are facilitated by, for example, effector innovations, stress, compatible pathogens and physiological similarities. Host jumping, subsequent establishment, and speciation takes place rapidly - within centuries and millennia rather than over millions of years. If pathogens are unable to evolve into neutral or mutualistic interactions with their hosts, they will eventually be removed from the host population, despite balancing trade-offs. Thus, generally, plant pathogens only survive in the course of evolution if they jump hosts. This is also reflected by the diversity patterns observed in many genera of plant pathogens, where it leads to a mosaic pattern of host groups over time, in which the original host group becomes increasingly obscure.
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Affiliation(s)
- Marco Thines
- Department of Biological Sciences, Institute of Ecology, Evolution and Diversity, Goethe University, Max-von-Laue-Str. 13, D-60486, Frankfurt am Main, Germany
- Senckenberg Gesellschaft für Naturforschung, Senckenberg Biodiversity and Climate Research Centre (BiK-F), Senckenberganlage 25, D-60325, Frankfurt am Main, Germany
- LOEWE Centre for Translational Biodiversity Genomics (TBG), Georg-Voigt-Str. 14-16, D-60325, Frankfurt am Main, Germany
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The fungal ribonuclease-like effector protein CSEP0064/BEC1054 represses plant immunity and interferes with degradation of host ribosomal RNA. PLoS Pathog 2019; 15:e1007620. [PMID: 30856238 PMCID: PMC6464244 DOI: 10.1371/journal.ppat.1007620] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 04/15/2019] [Accepted: 02/06/2019] [Indexed: 01/08/2023] Open
Abstract
The biotrophic fungal pathogen Blumeria graminis causes the powdery mildew disease of cereals and grasses. We present the first crystal structure of a B. graminis effector of pathogenicity (CSEP0064/BEC1054), demonstrating it has a ribonuclease (RNase)-like fold. This effector is part of a group of RNase-like proteins (termed RALPHs) which comprise the largest set of secreted effector candidates within the B. graminis genomes. Their exceptional abundance suggests they play crucial functions during pathogenesis. We show that transgenic expression of RALPH CSEP0064/BEC1054 increases susceptibility to infection in both monocotyledonous and dicotyledonous plants. CSEP0064/BEC1054 interacts in planta with the pathogenesis-related protein PR10. The effector protein associates with total RNA and weakly with DNA. Methyl jasmonate (MeJA) levels modulate susceptibility to aniline-induced host RNA fragmentation. In planta expression of CSEP0064/BEC1054 reduces the formation of this RNA fragment. We propose CSEP0064/BEC1054 is a pseudoenzyme that binds to host ribosomes, thereby inhibiting the action of plant ribosome-inactivating proteins (RIPs) that would otherwise lead to host cell death, an unviable interaction and demise of the fungus. Powdery mildews are common plant diseases which affect important crop plants including cereals such as wheat and barley. The fungi that cause this disease are obligate biotrophs: they have an absolute requirement for living host cells which they penetrate with feeding structures called haustoria. These fungi must be highly effective at avoiding immune recognition which would lead to death of the host cell and the pathogen. We assume they do this by delivering effector proteins to the host. While several hundred secreted effectors have been described in cereal powdery mildews, it is unknown how they work. Here, we use X-ray crystallography and nuclear magnetic resonance (NMR) spectroscopy to determine the structure and interactions of the effector CSEP0064/BEC1054, representative of the largest class of effectors resembling fungal RNases. We find that this effector binds nucleic acids. Expression of the effector in plants increases susceptibility to infection. Moreover, transgenic CSEP0064/BEC1054 expression in wheat inhibits the degradation of host ribosomal RNA induced by ribosome-inactivating proteins (RIPs). We propose a novel mechanism of action for the RNase-like effectors in powdery mildews: they may act as pseudoenzymes to inhibit the host RIPs, known components of plant immune responses that lead to host cell death.
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Good Riddance? Breaking Disease Susceptibility in the Era of New Breeding Technologies. AGRONOMY-BASEL 2018. [DOI: 10.3390/agronomy8070114] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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