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Zhuge J, Zhou X, Zhou L, Hu J, Guo K. The Plant Parasitic Nematodes Database: A Comprehensive Genomic Data Platform for Plant Parasitic Nematode Research. Int J Mol Sci 2023; 24:16841. [PMID: 38069165 PMCID: PMC10706385 DOI: 10.3390/ijms242316841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 10/24/2023] [Accepted: 11/24/2023] [Indexed: 12/18/2023] Open
Abstract
Plant parasitic nematodes are important phytopathogens that greatly affect the growth of agricultural and forestry plants. Scientists have conducted several studies to prevent and treat the diseases they cause. With the advent of the genomics era, the genome sequencing of plant parasitic nematodes has been considerably accelerated, and a large amount of data has been generated. This study developed the Plant Parasitic Nematodes Database (PPND), a platform to combine these data. The PPND contains genomic, transcriptomic, protein, and functional annotation data, allowing users to conduct BLAST searches and genome browser analyses and download bioinformatics data for in-depth research. PPND will be continuously updated, and new data will be integrated. PPND is anticipated to become a comprehensive genomics data platform for plant parasitic nematode research.
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Affiliation(s)
| | | | | | | | - Kai Guo
- School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou 311300, China; (J.Z.); (X.Z.); (L.Z.); (J.H.)
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2
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Cunha TJ, de Medeiros BAS, Lord A, Sørensen MV, Giribet G. Rampant loss of universal metazoan genes revealed by a chromosome-level genome assembly of the parasitic Nematomorpha. Curr Biol 2023; 33:3514-3521.e4. [PMID: 37467752 DOI: 10.1016/j.cub.2023.07.003] [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: 03/08/2023] [Revised: 05/21/2023] [Accepted: 07/03/2023] [Indexed: 07/21/2023]
Abstract
Parasites may manipulate host behavior to increase the odds of transmission or to reach the proper environment to complete their life cycle.1,2 Members of the phylum Nematomorpha (known as horsehair worms, hairworms, or Gordian worms) are large endoparasites that affect the behavior of their arthropod hosts. In terrestrial hosts, they cause erratic movements toward bodies of water,3,4,5,6 where the adult worm emerges from the host to find mates for reproduction. We present a chromosome-level genome assembly for the freshwater Acutogordius australiensis and a draft assembly for one of the few known marine species, Nectonema munidae. The assemblies span 201 Mbp and 213 Mbp in length (N50: 38 Mbp and 716 Kbp), respectively, and reveal four chromosomes in Acutogordius, which are largely rearranged compared to the inferred ancestral condition in animals. Both nematomorph genomes have a relatively low number of genes (11,114 and 8,717, respectively) and lack a high proportion (∼30%) of universal single-copy metazoan orthologs (BUSCO genes7). We demonstrate that missing genes are not an artifact of the assembly process, with the majority of missing orthologs being shared by the two independent assemblies. Missing BUSCOs are enriched for Gene Ontology (GO) terms associated with the organization of cilia and cell projections in other animals. We show that most cilium-related genes conserved across eukaryotes have been lost in Nematomorpha, providing a molecular basis for the suspected absence of ciliary structures in these animals.
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Affiliation(s)
- Tauana J Cunha
- Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA; Field Museum of Natural History, 1400 S DuSable Lake Shore Drive, Chicago, IL 60605, USA.
| | - Bruno A S de Medeiros
- Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA; Field Museum of Natural History, 1400 S DuSable Lake Shore Drive, Chicago, IL 60605, USA
| | - Arianna Lord
- Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
| | - Martin V Sørensen
- Natural History Museum of Denmark, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark
| | - Gonzalo Giribet
- Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
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3
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Santini S, Schenkelaars Q, Jourda C, Duchesne M, Belahbib H, Rocher C, Selva M, Riesgo A, Vervoort M, Leys SP, Kodjabachian L, Le Bivic A, Borchiellini C, Claverie JM, Renard E. The compact genome of the sponge Oopsacas minuta (Hexactinellida) is lacking key metazoan core genes. BMC Biol 2023; 21:139. [PMID: 37337252 DOI: 10.1186/s12915-023-01619-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 05/09/2023] [Indexed: 06/21/2023] Open
Abstract
BACKGROUND Explaining the emergence of the hallmarks of bilaterians is a central focus of evolutionary developmental biology-evodevo-and evolutionary genomics. For this purpose, we must both expand and also refine our knowledge of non-bilaterian genomes, especially by studying early branching animals, in particular those in the metazoan phylum Porifera. RESULTS We present a comprehensive analysis of the first whole genome of a glass sponge, Oopsacas minuta, a member of the Hexactinellida. Studying this class of sponge is evolutionary relevant because it differs from the three other Porifera classes in terms of development, tissue organization, ecology, and physiology. Although O. minuta does not exhibit drastic body simplifications, its genome is among the smallest of animal genomes sequenced so far, and surprisingly lacks several metazoan core genes (including Wnt and several key transcription factors). Our study also provides the complete genome of a symbiotic Archaea dominating the associated microbial community: a new Thaumarchaeota species. CONCLUSIONS The genome of the glass sponge O. minuta differs from all other available sponge genomes by its compactness and smaller number of encoded proteins. The unexpected loss of numerous genes previously considered ancestral and pivotal for metazoan morphogenetic processes most likely reflects the peculiar syncytial tissue organization in this group. Our work further documents the importance of convergence during animal evolution, with multiple convergent evolution of septate-like junctions, electrical-signaling and multiciliated cells in metazoans.
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Affiliation(s)
- Sébastien Santini
- Aix Marseille Univ, CNRS, IGS, UMR 7256, IMM, IM2B, IOM, Marseille, France
| | - Quentin Schenkelaars
- Aix Marseille Univ, Avignon Univ, CNRS, IRD, IMBE, Marseille, France
- Institut Jacques Monod, CNRS, UMR 7592, Univ Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Cyril Jourda
- Aix Marseille Univ, CNRS, IGS, UMR 7256, IMM, IM2B, IOM, Marseille, France
- CIRAD, UMR PVBMT, La Réunion, France
| | - Marc Duchesne
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| | - Hassiba Belahbib
- Aix Marseille Univ, CNRS, IGS, UMR 7256, IMM, IM2B, IOM, Marseille, France
| | - Caroline Rocher
- Aix Marseille Univ, Avignon Univ, CNRS, IRD, IMBE, Marseille, France
| | - Marjorie Selva
- Aix Marseille Univ, Avignon Univ, CNRS, IRD, IMBE, Marseille, France
| | - Ana Riesgo
- Department of Biodiversity and Evolutionary Biology, Madrid, Spain
- Department of Life Sciences, Natural History Museum of London, London, SW7 5BD, UK
| | - Michel Vervoort
- Institut Jacques Monod, CNRS, UMR 7592, Univ Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Sally P Leys
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| | - Laurent Kodjabachian
- Aix Marseille Univ, CNRS, IBDM, UMR 7288, Turing Center for Living Systems, Marseille, France
| | - André Le Bivic
- Aix Marseille Univ, CNRS, IBDM, UMR 7288, Marseille, France
| | | | | | - Emmanuelle Renard
- Aix Marseille Univ, Avignon Univ, CNRS, IRD, IMBE, Marseille, France.
- Aix Marseille Univ, CNRS, IBDM, UMR 7288, Marseille, France.
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4
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Arora D, Hernandez AG, Walden KKO, Fields CJ, Yan G. First Draft Genome Assembly of Root-Lesion Nematode Pratylenchus scribneri Generated Using Long-Read Sequencing. Int J Mol Sci 2023; 24:ijms24087311. [PMID: 37108472 PMCID: PMC10138993 DOI: 10.3390/ijms24087311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/06/2023] [Accepted: 04/13/2023] [Indexed: 04/29/2023] Open
Abstract
Root-lesion nematodes (genus Pratylenchus) belong to a diverse group of plant-parasitic nematodes (PPN) with a worldwide distribution. Despite being an economically important PPN group of more than 100 species, genome information related to Pratylenchus genus is scarcely available. Here, we report the draft genome assembly of Pratylenchus scribneri generated on the PacBio Sequel IIe System using the ultra-low DNA input HiFi sequencing workflow. The final assembly created using 500 nematodes consisted of 276 decontaminated contigs, with an average contig N50 of 1.72 Mb and an assembled draft genome size of 227.24 Mb consisting of 51,146 predicted protein sequences. The benchmarking universal single-copy ortholog (BUSCO) analysis with 3131 nematode BUSCO groups indicated that 65.4% of the BUSCOs were complete, whereas 24.0%, 41.4%, and 1.8% were single-copy, duplicated, and fragmented, respectively, and 32.8% were missing. The outputs from GenomeScope2 and Smudgeplots converged towards a diploid genome for P. scribneri. The data provided here will facilitate future studies on host plant-nematode interactions and crop protection at the molecular level.
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Affiliation(s)
- Deepika Arora
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58105, USA
| | - Alvaro G Hernandez
- Roy J. Carver Biotechnology Center, University of Illinois at Urbana-Champaign, Urbana, IL 61820, USA
| | - Kimberly K O Walden
- Roy J. Carver Biotechnology Center, University of Illinois at Urbana-Champaign, Urbana, IL 61820, USA
| | - Christopher J Fields
- Roy J. Carver Biotechnology Center, University of Illinois at Urbana-Champaign, Urbana, IL 61820, USA
| | - Guiping Yan
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58105, USA
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Singh AK, Das A, Joshi I, Kumar M, Kohli D, Pankaj, Gaikwad K, Jain PK, Sirohi A. Nematode Genome Announcement: A Draft Genome of Seed Gall Nematode, Anguina tritici. J Nematol 2023; 55:20230031. [PMID: 38026554 PMCID: PMC10656185 DOI: 10.2478/jofnem-2023-0031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Indexed: 12/01/2023] Open
Abstract
Anguina tritici is the first plant-parasitic nematode described in literature, dating back to the year 1743. It is responsible for causing earcockle (seed gall) and tundu diseases in wheat and rye. Notably, this nematode has been observed to survive in an anhydrobiotic state for up to 32 years within wheat seed galls. These exceptional characteristics have inspired the sequencing of the A. tritici genome. In this study, we present the initial draft genome of A. tritici, obtained using the Illumina MiSeq platform with coverage of 60-fold. The genome is estimated to have a size of 164 Mb and comprises 39,965 protein-coding genes, exhibiting a GC content of 39.1%. The availability of this genome data will serve as a foundation for future functional biological investigations, particularly for genes whose functions remain unknown to this day.
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Affiliation(s)
- Ashish Kumar Singh
- Division of Nematology, ICAR-Indian Agricultural Research Institute, Pusa Campus, New Delhi-110012, India
- Division of Crop Protection, ICAR-Vivekananda Parvatiya Krishi Anusandhan Sansthan, Almora, Uttarakhand263601, India
| | - Antara Das
- ICAR-National Institute for Plant Biotechnology, Pusa Campus, New Delhi, 110012, India
| | - Ila Joshi
- ICAR-National Institute for Plant Biotechnology, Pusa Campus, New Delhi, 110012, India
| | - Manish Kumar
- Division of Nematology, ICAR-Indian Agricultural Research Institute, Pusa Campus, New Delhi-110012, India
| | - Deshika Kohli
- ICAR-National Institute for Plant Biotechnology, Pusa Campus, New Delhi, 110012, India
| | - Pankaj
- Division of Nematology, ICAR-Indian Agricultural Research Institute, Pusa Campus, New Delhi-110012, India
| | - Kishor Gaikwad
- ICAR-National Institute for Plant Biotechnology, Pusa Campus, New Delhi, 110012, India
| | - Pradeep Kumar Jain
- ICAR-National Institute for Plant Biotechnology, Pusa Campus, New Delhi, 110012, India
| | - Anil Sirohi
- Division of Nematology, ICAR-Indian Agricultural Research Institute, Pusa Campus, New Delhi-110012, India
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Abstract
The nematode Caenorhabditis elegans has shed light on many aspects of eukaryotic biology, including genetics, development, cell biology, and genomics. A major factor in the success of C. elegans as a model organism has been the availability, since the late 1990s, of an essentially gap-free and well-annotated nuclear genome sequence, divided among 6 chromosomes. In this review, we discuss the structure, function, and biology of C. elegans chromosomes and then provide a general perspective on chromosome biology in other diverse nematode species. We highlight malleable chromosome features including centromeres, telomeres, and repetitive elements, as well as the remarkable process of programmed DNA elimination (historically described as chromatin diminution) that induces loss of portions of the genome in somatic cells of a handful of nematode species. An exciting future prospect is that nematode species may enable experimental approaches to study chromosome features and to test models of chromosome evolution. In the long term, fundamental insights regarding how speciation is integrated with chromosome biology may be revealed.
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Affiliation(s)
- Peter M Carlton
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Richard E Davis
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Denver, CO 80045, USA.,RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Shawn Ahmed
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA.,Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
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7
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Advances and Discoveries in Myxozoan Genomics. Trends Parasitol 2021; 37:552-568. [PMID: 33619004 DOI: 10.1016/j.pt.2021.01.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/20/2021] [Accepted: 01/23/2021] [Indexed: 12/21/2022]
Abstract
Myxozoans are highly diverse and globally distributed cnidarian endoparasites in freshwater and marine habitats. They have adopted a heteroxenous life cycle, including invertebrate and fish hosts, and have been associated with diseases in aquaculture and wild fish stocks. Despite their importance, genomic resources of myxozoans have proven difficult to obtain due to their miniaturized and derived genome character and close associations with fish tissues. The first 'omic' datasets have now become the main resource for a better understanding of host-parasite interactions, virulence, and diversity, but also the evolutionary history of myxozoans. In this review, we discuss recent genomic advances in the field and outline outstanding questions to be answered with continuous and improved efforts of generating myxozoan genomic data.
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8
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Montarry J, Mimee B, Danchin EGJ, Koutsovoulos GD, Ste-Croix DT, Grenier E. Recent Advances in Population Genomics of Plant-Parasitic Nematodes. PHYTOPATHOLOGY 2021; 111:40-48. [PMID: 33151824 DOI: 10.1094/phyto-09-20-0418-rvw] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Plant-parasitic nematodes are a costly burden of crop production. Ubiquitous in nature, phytoparasitic nematodes are associated with nearly every important agricultural crop and represent a significant constraint on global food security. Population genetics is a key discipline in plant nematology to understand aspects of the life strategies of these parasites, in particular their modes of reproduction, geographic origins, evolutionary histories, and dispersion abilities. Advances in high-throughput sequencing technologies have enabled a recent but active effort in genomic analyses of plant-parasitic nematodes. Such genomic approaches applied to multiple populations are providing new insights into the molecular and evolutionary processes that underpin the establishment of these nematodes and into a better understanding of the genetic and mechanistic basis of their pathogenicity and adaptation to their host plants. In this review, we attempt to update information about genome resources and genotyping techniques useful for nematologists who are thinking about initiating population genomics or genome sequencing projects. This review is intended also to foster the development of population genomics in plant-parasitic nematodes through highlighting recent publications that illustrate the potential for this approach to identify novel molecular markers or genes of interest and improve our knowledge of the genome variability, pathogenicity, and evolutionary potential of plant-parasitic nematodes.
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Affiliation(s)
| | - Benjamin Mimee
- Saint-Jean-sur-Richelieu Research and Development Centre, Agriculture and Agri-Food Canada, Saint-Jean-sur-Richelieu, Québec, Canada
| | - Etienne G J Danchin
- Institut Sophia Agrobiotech, Université Côte d'Azur, INRAE, CNRS, Sophia Antipolis, France
| | | | - Dave T Ste-Croix
- Saint-Jean-sur-Richelieu Research and Development Centre, Agriculture and Agri-Food Canada, Saint-Jean-sur-Richelieu, Québec, Canada
| | - Eric Grenier
- IGEPP, INRAE, Institut Agro, Univ Rennes, 35650, Le Rheu, France
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Vieira P, Shao J, Vijayapalani P, Maier TR, Pellegrin C, Eves-van den Akker S, Baum TJ, Nemchinov LG. A new esophageal gland transcriptome reveals signatures of large scale de novo effector birth in the root lesion nematode Pratylenchus penetrans. BMC Genomics 2020; 21:738. [PMID: 33096989 PMCID: PMC7585316 DOI: 10.1186/s12864-020-07146-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 10/12/2020] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND The root lesion nematode Pratylenchus penetrans is a migratory plant-parasitic nematode responsible for economically important losses in a wide number of crops. Despite the importance of P. penetrans, the molecular mechanisms employed by this nematode to promote virulence remain largely unknown. RESULTS Here we generated a new and comprehensive esophageal glands-specific transcriptome library for P. penetrans. In-depth analysis of this transcriptome enabled a robust identification of a catalogue of 30 new candidate effector genes, which were experimentally validated in the esophageal glands by in situ hybridization. We further validated the expression of a multifaceted network of candidate effectors during the interaction with different plants. To advance our understanding of the "effectorome" of P. penetrans, we adopted a phylogenetic approach and compared the expanded effector repertoire of P. penetrans to the genome/transcriptome of other nematode species with similar or contrasting parasitism strategies. Our data allowed us to infer plausible evolutionary histories that shaped the effector repertoire of P. penetrans, as well as other close and distant plant-parasitic nematodes. Two remarkable trends were apparent: 1) large scale effector birth in the Pratylenchidae in general and P. penetrans in particular, and 2) large scale effector death in sedentary (endo) plant-parasitic nematodes. CONCLUSIONS Our study doubles the number of validated Pratylenchus penetrans effectors reported in the literature. The dramatic effector gene gain in P. penetrans could be related to the remarkable ability of this nematode to parasitize a large number of plants. Our data provide valuable insights into nematode parasitism and contribute towards basic understating of the adaptation of P. penetrans and other root lesion nematodes to specific host plants.
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Affiliation(s)
- Paulo Vieira
- USDA-ARS, Molecular Plant Pathology Laboratory, Beltsville, MD, 20705-2350, USA.
- School of Plant and Environmental Science, Virginia Tech, Blacksburg, VA, 24061, USA.
| | - Jonathan Shao
- USDA-ARS, Molecular Plant Pathology Laboratory, Beltsville, MD, 20705-2350, USA
| | | | - Thomas R Maier
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, 50011, USA
| | - Clement Pellegrin
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | | | - Thomas J Baum
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, 50011, USA
| | - Lev G Nemchinov
- USDA-ARS, Molecular Plant Pathology Laboratory, Beltsville, MD, 20705-2350, USA
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10
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Pokhare SS, Thorpe P, Hedley P, Morris J, Habash SS, Elashry A, Eves-van den Akker S, Grundler FMW, Jones JT. Signatures of adaptation to a monocot host in the plant-parasitic cyst nematode Heterodera sacchari. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:1263-1274. [PMID: 32623778 DOI: 10.1111/tpj.14910] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 06/18/2020] [Indexed: 05/03/2023]
Abstract
Interactions between plant-parasitic nematodes and their hosts are mediated by effectors, i.e. secreted proteins that manipulate the plant to the benefit of the pathogen. To understand the role of effectors in host adaptation in nematodes, we analysed the transcriptome of Heterodera sacchari, a cyst nematode parasite of rice (Oryza sativa) and sugarcane (Saccharum officinarum). A multi-gene phylogenetic analysis showed that H. sacchari and the cereal cyst nematode Heterodera avenae share a common evolutionary origin and that they evolved to parasitise monocot plants from a common dicot-parasitic ancestor. We compared the effector repertoires of H. sacchari with those of the dicot parasites Heterodera glycines and Globodera rostochiensis to understand the consequences of this transition. While, in general, effector repertoires are similar between the species, comparing effectors and non-effectors of H. sacchari and G. rostochiensis shows that effectors have accumulated more mutations than non-effectors. Although most effectors show conserved spatiotemporal expression profiles and likely function, some H. sacchari effectors are adapted to monocots. This is exemplified by the plant-peptide hormone mimics, the CLAVATA3/EMBRYO SURROUNDING REGION-like (CLE) effectors. Peptide hormones encoded by H. sacchari CLE effectors are more similar to those from rice than those from other plants, or those from other plant-parasitic nematodes. We experimentally validated the functional significance of these observations by demonstrating that CLE peptides encoded by H. sacchari induce a short root phenotype in rice, whereas those from a related dicot parasite do not. These data provide a functional example of effector evolution that co-occurred with the transition from a dicot-parasitic to a monocot-parasitic lifestyle.
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Affiliation(s)
- Somnath S Pokhare
- Department of Molecular Phytomedicine, Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, 53115, Germany
- Crop Protection Division, ICAR-National Rice Research Institute, Cuttack, Odisha, 753006, India
| | - Peter Thorpe
- The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
- School of Medicine, University of St Andrews, North Haugh, St Andrews, KY16 9TZ, UK
| | - Pete Hedley
- The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
| | - Jennifer Morris
- The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
| | - Samer S Habash
- Department of Molecular Phytomedicine, Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, 53115, Germany
| | - Abdelnaser Elashry
- Department of Molecular Phytomedicine, Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, 53115, Germany
| | | | - Florian M W Grundler
- Department of Molecular Phytomedicine, Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, 53115, Germany
| | - John T Jones
- The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
- School of Biology, University of St Andrews, North Haugh, St Andrews, KY16 9TZ, UK
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11
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Vieira P, Nemchinov LG. An Expansin-Like Candidate Effector Protein from Pratylenchus penetrans Modulates Immune Responses in Nicotiana benthamiana. PHYTOPATHOLOGY 2020; 110:684-693. [PMID: 31680651 DOI: 10.1094/phyto-09-19-0336-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The root lesion nematode (RLN) Pratylenchus penetrans is a migratory species that attacks a broad range of crops. After the RLN is initially attracted to host roots by root exudates and compounds, it releases secretions that are critical for successful parasitism. Among those secretions are nematode virulence factors or effectors that facilitate the entry and migration of nematodes through the roots and modulate plant immune defenses. The recognition of the effectors by host resistance proteins leads to effector-triggered immunity and incompatible plant-nematode interactions. Although many candidate effectors of the RLN and other plant-parasitic nematodes have been identified, the detailed mechanisms of their functions and particularly, their host targets remain largely unexplored. In this study, we sequenced and annotated genes encoding expansin-like proteins, which are major candidate effectors of P. penetrans. One of the genes, Pp-EXPB1, which was the most highly expressed during nematode infection in different plant species, was further functionally characterized via transient expression in the model plant Nicotiana benthamiana and global transcriptome profiling of gene expression changes triggered by this candidate effector in plants. As a result of this investigation, the biological roles of Pp-EXPB1 in nematode parasitism were proposed, the putative cellular targets of the proteins were identified, and the molecular mechanisms of plant responses to the nematode-secreted proteins were outlined.
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Affiliation(s)
- Paulo Vieira
- Molecular Plant Pathology Laboratory, U.S. Department of Agriculture-Agricultural Research Service, Beltsville, MD 20705-2350
- School of Plant and Environmental Science, Virginia Tech, Blacksburg, VA 24061
| | - Lev G Nemchinov
- Molecular Plant Pathology Laboratory, U.S. Department of Agriculture-Agricultural Research Service, Beltsville, MD 20705-2350
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12
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Slyusarev GS, Starunov VV, Bondarenko AS, Zorina NA, Bondarenko NI. Extreme Genome and Nervous System Streamlining in the Invertebrate Parasite Intoshia variabili. Curr Biol 2020; 30:1292-1298.e3. [PMID: 32084405 DOI: 10.1016/j.cub.2020.01.061] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 11/21/2019] [Accepted: 01/17/2020] [Indexed: 11/19/2022]
Abstract
Orthonectida is a small, rare, and in many aspects enigmatic group of organisms with a unique life cycle and a highly simplified adult free-living stage parasitizing various marine invertebrates [1, 2]. Phylogenetic relationships of Orthonectida have remained controversial for a long time. According to recent data, they are close to Annelida, specifically to Clitellata [3-5]. Several studies have shown that parasitism can not only lead to a dramatic reduction of the body plan and morphological structures but also affect organisms at the genomic level [6, 7]. Comparative studies of parasites and closely related non-parasitic species could clarify the genome reduction degree and evolution of parasitism. Here, we report on the morphology, genome structure, and content of the smallest known Orthonectida species Intoshia variabili, inhabiting the flatworm Graffiellus croceus. This orthonectid with an extremely simplified nervous system demonstrates the smallest known genome (15.3 Mbp) and one of the lowest reported so far gene numbers (5,120 protein-coding genes) among metazoans. The genome is extremely compact, due to a significant reduction of gene number, intergenic regions, intron length, and repetitive elements. The small genome size is probably a result of extreme genome reduction due to their parasitic lifestyle, as well as of simplification and miniaturization of the free-living stages. Our data could provide further insights into the evolution of parasitism and could help to define a minimal bilaterian gene set.
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Affiliation(s)
- George S Slyusarev
- Department of Invertebrate Zoology, Faculty of Biology, St. Petersburg State University, Universitetskaya nab. 7/9, 199034 St. Petersburg, Russia
| | - Viktor V Starunov
- Department of Invertebrate Zoology, Faculty of Biology, St. Petersburg State University, Universitetskaya nab. 7/9, 199034 St. Petersburg, Russia; Zoological Institute RAS, Universitetskaya nab. 1, 199034 St. Petersburg, Russia
| | - Anton S Bondarenko
- Faculty of Physics, Saint-Petersburg State University, Universitetskaya nab. 7/9, 199034 St. Petersburg, Russia
| | - Natalia A Zorina
- Department of Invertebrate Zoology, Faculty of Biology, St. Petersburg State University, Universitetskaya nab. 7/9, 199034 St. Petersburg, Russia
| | - Natalya I Bondarenko
- Department of Invertebrate Zoology, Faculty of Biology, St. Petersburg State University, Universitetskaya nab. 7/9, 199034 St. Petersburg, Russia.
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13
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Mathew R, Opperman CH. The genome of the migratory nematode, Radopholus similis, reveals signatures of close association to the sedentary cyst nematodes. PLoS One 2019; 14:e0224391. [PMID: 31652297 PMCID: PMC6814228 DOI: 10.1371/journal.pone.0224391] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 10/11/2019] [Indexed: 11/19/2022] Open
Abstract
Radopholus similis, commonly known as the burrowing nematode, is an important pest of myriad crops and ornamentals including banana (Musa spp.) and Citrus spp. In order to characterize the potential role of putative effectors encoded by R. similis genes we compared predicted proteins from a draft R. similis genome with other plant-parasitic nematodes in order to define the suite of excreted/secreted proteins that enable it to function as a parasite and to ascertain the phylogenetic position of R. similis in the Tylenchida order. Identification and analysis of candidate genes encoding for key plant cell-wall degrading enzymes including GH5 cellulases, PL3 pectate lyases and GH28 polygalactouranase revealed a pattern of occurrence similar to other PPNs, although with closest phylogenetic associations to the sedentary cyst nematodes. We also observed the absence of a suite of effectors essential for feeding site formation in the cyst nematodes. Clustering of various orthologous genes shared by R. similis with other nematodes showed higher overlap with the cyst nematodes than with the root-knot or other migratory endoparasitic nematodes. The data presented here support the hypothesis that R. similis is evolutionarily closer to the cyst nematodes, however, differences in the effector repertoire delineate ancient divergence of parasitism, probably as a consequence of niche specialization. These similarities and differences further underscore distinct evolutionary relationships during the evolution of parasitism in this group of nematodes.
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Affiliation(s)
- Reny Mathew
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC United States of America
| | - Charles H. Opperman
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC United States of America
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14
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Yoshimura J, Ichikawa K, Shoura MJ, Artiles KL, Gabdank I, Wahba L, Smith CL, Edgley ML, Rougvie AE, Fire AZ, Morishita S, Schwarz EM. Recompleting the Caenorhabditis elegans genome. Genome Res 2019; 29:1009-1022. [PMID: 31123080 PMCID: PMC6581061 DOI: 10.1101/gr.244830.118] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 03/11/2019] [Indexed: 01/14/2023]
Abstract
Caenorhabditis elegans was the first multicellular eukaryotic genome sequenced to apparent completion. Although this assembly employed a standard C. elegans strain (N2), it used sequence data from several laboratories, with DNA propagated in bacteria and yeast. Thus, the N2 assembly has many differences from any C. elegans available today. To provide a more accurate C. elegans genome, we performed long-read assembly of VC2010, a modern strain derived from N2. Our VC2010 assembly has 99.98% identity to N2 but with an additional 1.8 Mb including tandem repeat expansions and genome duplications. For 116 structural discrepancies between N2 and VC2010, 97 structures matching VC2010 (84%) were also found in two outgroup strains, implying deficiencies in N2. Over 98% of N2 genes encoded unchanged products in VC2010; moreover, we predicted ≥53 new genes in VC2010. The recompleted genome of C. elegans should be a valuable resource for genetics, genomics, and systems biology.
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Affiliation(s)
- Jun Yoshimura
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8583, Japan
| | - Kazuki Ichikawa
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8583, Japan
| | - Massa J Shoura
- Department of Pathology, Stanford University, Stanford, California 94305, USA
| | - Karen L Artiles
- Department of Pathology, Stanford University, Stanford, California 94305, USA
| | - Idan Gabdank
- Department of Genetics, Stanford University, Stanford, California 94305, USA
| | - Lamia Wahba
- Department of Pathology, Stanford University, Stanford, California 94305, USA
| | - Cheryl L Smith
- Department of Pathology, Stanford University, Stanford, California 94305, USA.,Department of Genetics, Stanford University, Stanford, California 94305, USA
| | - Mark L Edgley
- Department of Zoology and Michael Smith Laboratories, University of British Columbia, Vancouver V6T 1Z3, British Columbia, Canada
| | - Ann E Rougvie
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota 55454, USA
| | - Andrew Z Fire
- Department of Pathology, Stanford University, Stanford, California 94305, USA.,Department of Genetics, Stanford University, Stanford, California 94305, USA
| | - Shinichi Morishita
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8583, Japan
| | - Erich M Schwarz
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853, USA
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15
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Perrine-Walker F. Interactions of endoparasitic and ectoparasitic nematodes within the plant root system. FUNCTIONAL PLANT BIOLOGY : FPB 2019; 46:295-303. [PMID: 32172739 DOI: 10.1071/fp18176] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 12/07/2018] [Indexed: 05/27/2023]
Abstract
Root-knot and cyst nematodes have sophisticated mechanisms to invade their plant hosts to reprogram the plant developmental program to induce feeding structures essential for nematode survival and reproduction. This has a detrimental effect on the plant as this sedentary endoparasitic interaction affects the growth and yields of many crop plants. However, other migratory endoparasitic nematodes that do not establish root feeding sites are as aggressive on many crop plants. With new information gained from the genome and transcriptomes of the migratory endoparasitic nematode, Pratylenchus spp., this review compares the different lifestyles and the pathogenic interactions these nematodes have with their plant host. Pratylenchus spp. utilises a common arsenal of effectors involved in plant cell wall degradation and the manipulation of plant host innate immunity. The absence of specific cell reprogramming effector genes may explain its migratory endoparasitic lifestyle, making it relevant to pest management approaches in Australia.
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Affiliation(s)
- Francine Perrine-Walker
- Sydney Institute of Agriculture, School of Life and Environmental Sciences, University of Sydney, Biomedical Building C81, 1 Central Avenue, Australian Technology Park, Eveleigh, NSW 2015, Australia. Email
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16
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Bell CA, Lilley CJ, McCarthy J, Atkinson HJ, Urwin PE. Plant-parasitic nematodes respond to root exudate signals with host-specific gene expression patterns. PLoS Pathog 2019; 15:e1007503. [PMID: 30707749 PMCID: PMC6373980 DOI: 10.1371/journal.ppat.1007503] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 02/13/2019] [Accepted: 12/03/2018] [Indexed: 12/20/2022] Open
Abstract
Plant parasitic nematodes must be able to locate and feed from their host in order to survive. Here we show that Pratylenchus coffeae regulates the expression of selected cell-wall degrading enzyme genes relative to the abundance of substrate in root exudates, thereby tailoring gene expression for root entry of the immediate host. The concentration of cellulose or xylan within the exudate determined the level of β-1,4-endoglucanase (Pc-eng-1) and β-1,4-endoxylanase (Pc-xyl) upregulation respectively. Treatment of P. coffeae with cellulose or xylan or with root exudates deficient in cellulose or xylan conferred a specific gene expression response of Pc-eng-1 or Pc-xyl respectively with no effect on expression of another cell wall degrading enzyme gene, a pectate lyase (Pc-pel). RNA interference confirmed the importance of regulating these genes as lowered transcript levels reduced root penetration by the nematode. Gene expression in this plant parasitic nematode is therefore influenced, in a host-specific manner, by cell wall components that are either secreted by the plant or released by degradation of root tissue. Transcriptional plasticity may have evolved as an adaptation for host recognition and increased root invasion by this polyphagous species. Plant parasitic nematodes feed from plant roots to support their development. In order to enter and reproduce within the host the nematode must interact with the components exuded by the root. The components are known to vary between individual plant species thus presenting different challenges for the nematode. We observe upregulation of two cell wall degrading enzyme genes in Pratylenchus coffeae upon exposure to root exudates. The nematode genes are differentially expressed dependent upon the identity of the plant. The relative expression of each gene correlates with the abundance of the encoded enzyme substrate in the nematode environment, indicating that the nematode perceives these components and responds by tailoring gene expression for what is currently required for host-parasitism. This ability may explain the wide host range of this nematode species and may be shared by other parasites.
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Affiliation(s)
| | | | | | - Howard J. Atkinson
- Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - P. E. Urwin
- Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
- * E-mail:
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17
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Ferrández-Roldán A, Martí-Solans J, Cañestro C, Albalat R. Oikopleura dioica: An Emergent Chordate Model to Study the Impact of Gene Loss on the Evolution of the Mechanisms of Development. Results Probl Cell Differ 2019; 68:63-105. [PMID: 31598853 DOI: 10.1007/978-3-030-23459-1_4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The urochordate Oikopleura dioica is emerging as a nonclassical animal model in the field of evolutionary developmental biology (a.k.a. evo-devo) especially attractive for investigating the impact of gene loss on the evolution of mechanisms of development. This is because this organism fulfills the requirements of an animal model (i.e., has a simple and accessible morphology, a short generation time and life span, and affordable culture in the laboratory and amenable experimental manipulation), but also because O. dioica occupies a key phylogenetic position to understand the diversification and origin of our own phylum, the chordates. During its evolution, O. dioica genome has suffered a drastic process of compaction, becoming the smallest known chordate genome, a process that has been accompanied by exacerbating amount of gene losses. Interestingly, however, despite the extensive gene losses, including entire regulatory pathways essential for the embryonic development of other chordates, O. dioica retains the typical chordate body plan. This unexpected situation led to the formulation of the so-called inverse paradox of evo-devo, that is, when a genetic diversity is able to maintain a phenotypic unity. This chapter reviews the biological features of O. dioica as a model animal, along with the current data on the evolution of its genes and genome. We pay special attention to the numerous examples of gene losses that have taken place during the evolution of this unique animal model, which is helping us to understand to which the limits of evo-devo can be pushed off.
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Affiliation(s)
- Alfonso Ferrández-Roldán
- Facultat de Biologia, Departament de Genètica, Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Catalonia, Spain
| | - Josep Martí-Solans
- Facultat de Biologia, Departament de Genètica, Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Catalonia, Spain
| | - Cristian Cañestro
- Facultat de Biologia, Departament de Genètica, Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Catalonia, Spain
| | - Ricard Albalat
- Facultat de Biologia, Departament de Genètica, Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Catalonia, Spain.
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Vieira P, Maier TR, Eves‐van den Akker S, Howe DK, Zasada I, Baum TJ, Eisenback JD, Kamo K. Identification of candidate effector genes of Pratylenchus penetrans. MOLECULAR PLANT PATHOLOGY 2018; 19:1887-1907. [PMID: 29424950 PMCID: PMC6638058 DOI: 10.1111/mpp.12666] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 02/06/2018] [Accepted: 02/07/2018] [Indexed: 05/02/2023]
Abstract
Pratylenchus penetrans is one of the most important species of root lesion nematodes (RLNs) because of its detrimental and economic impact in a wide range of crops. Similar to other plant-parasitic nematodes (PPNs), P. penetrans harbours a significant number of secreted proteins that play key roles during parasitism. Here, we combined spatially and temporally resolved next-generation sequencing datasets of P. penetrans to select a list of candidate genes aimed at the identification of a panel of effector genes for this species. We determined the spatial expression of transcripts of 22 candidate effectors within the oesophageal glands of P. penetrans by in situ hybridization. These comprised homologues of known effectors of other PPNs with diverse putative functions, as well as novel pioneer effectors specific to RLNs. It is noteworthy that five of the pioneer effectors encode extremely proline-rich proteins. We then combined in situ localization of effectors with available genomic data to identify a non-coding motif enriched in promoter regions of a subset of P. penetrans effectors, and thus a putative hallmark of spatial expression. Expression profiling analyses of a subset of candidate effectors confirmed their expression during plant infection. Our current results provide the most comprehensive panel of effectors found for RLNs. Considering the damage caused by P. penetrans, this information provides valuable data to elucidate the mode of parasitism of this nematode and offers useful suggestions regarding the potential use of P. penetrans-specific target effector genes to control this important pathogen.
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Affiliation(s)
- Paulo Vieira
- Department of Plant Pathology, Physiology, and Weed ScienceVirginia TechBlacksburgVA 24061USA
- Floral and Nursery Plants Research Unit, U.S. National Arboretum, U.S. Department of AgricultureBeltsvilleMD 20705‐2350USA
| | - Thomas R. Maier
- Department of Plant Pathology and MicrobiologyIowa State UniversityAmesIA 50011USA
| | - Sebastian Eves‐van den Akker
- Department of Biological ChemistryJohn Innes Centre, Norwich Research ParkNorwich NR4 7UHUK
- School of Life SciencesUniversity of DundeeDundee DD1 5EHUK
| | - Dana K. Howe
- Department of Integrative BiologyOregon State UniversityCorvallisOR 97331USA
| | - Inga Zasada
- Horticultural Crops Research LaboratoryU.S. Department of AgricultureCorvallisOR 97330USA
| | - Thomas J. Baum
- Department of Plant Pathology and MicrobiologyIowa State UniversityAmesIA 50011USA
| | - Jonathan D. Eisenback
- Department of Plant Pathology, Physiology, and Weed ScienceVirginia TechBlacksburgVA 24061USA
| | - Kathryn Kamo
- Floral and Nursery Plants Research Unit, U.S. National Arboretum, U.S. Department of AgricultureBeltsvilleMD 20705‐2350USA
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19
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Roderick H, Urwin PE, Atkinson HJ. Rational design of biosafe crop resistance to a range of nematodes using RNA interference. PLANT BIOTECHNOLOGY JOURNAL 2018; 16:520-529. [PMID: 28703405 PMCID: PMC5787825 DOI: 10.1111/pbi.12792] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 07/05/2017] [Accepted: 07/05/2017] [Indexed: 05/31/2023]
Abstract
Double-stranded RNA (dsRNA) molecules targeting two genes have been identified that suppress economically important parasitic nematode species of banana. Proteasomal alpha subunit 4 (pas-4) and Actin-4 (act-4) were identified from a survey of sequence databases and cloned sequences for genes conserved across four pests of banana, Radopholus similis, Pratylenchus coffeae, Meloidogyne incognita and Helicotylenchus multicinctus. These four species were targeted with dsRNAs containing exact 21 nucleotide matches to the conserved regions. Potential off-target effects were limited by comparison with Caenorhabditis, Drosophila, rat, rice and Arabidopsis genomes. In vitro act-4 dsRNA treatment of R. similis suppressed target gene expression by 2.3-fold, nematode locomotion by 66 ± 4% and nematode multiplication on carrot discs by 49 ± 5%. The best transgenic carrot hairy root lines expressing act-4 or pas-4 dsRNA reduced transcript message abundance of target genes in R. similis by 7.9-fold and fourfold and nematode multiplication by 94 ± 2% and 69 ± 3%, respectively. The same act-4 and pas-4 lines reduced P. coffeae target transcripts by 1.7- and twofold and multiplication by 50 ± 6% and 73 ± 8%. Multiplication of M. incognita on the pas-4 lines was reduced by 97 ± 1% and 99 ± 1% while target transcript abundance was suppressed 4.9- and 5.6-fold. There was no detectable RNAi effect on nontarget nematodes exposed to dsRNAs targeting parasitic nematodes. This work defines a framework for development of a range of nonprotein defences to provide broad resistance to pests and pathogens of crops.
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Abstract
Nematodes are highly abundant animals, and many species have a parasitic lifestyle. Nematode parasites are important pathogens of humans and other animals, and there is considerable interest in understanding their molecular and genomic adaptations to nematode parasitism. This has been approached in three main ways: comparing the genomes of closely related parasitic and free-living taxa, comparing the gene expression of parasitic and free-living life cycle stages of parasitic nematode species, and analysing the molecules that parasitic nematodes excrete and secrete. To date, these studies show that many species of parasitic nematodes have genomes that have large gene families coding for proteases/peptidases, protease inhibitors, SCP/TAPS proteins and acetylcholinesterases, and in many cases there is evidence that these appear to be used by parasitic stages inside hosts, and are often secreted. Many parasitic nematodes have taxa-restricted gene families that also appear to be involved in parasitism, emphasizing that there is still much to be discovered about what it takes to be a parasitic nematode.
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Affiliation(s)
- Mark Viney
- Corresponding author: Mark Viney, School of Biological Sciences, University of Bristol, Bristol, UK. Tel.: 0117 394 1203; E-mail:
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21
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Zheng J, Peng D, Chen L, Liu H, Chen F, Xu M, Ju S, Ruan L, Sun M. The Ditylenchus destructor genome provides new insights into the evolution of plant parasitic nematodes. Proc Biol Sci 2017; 283:rspb.2016.0942. [PMID: 27466450 DOI: 10.1098/rspb.2016.0942] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 07/05/2016] [Indexed: 01/08/2023] Open
Abstract
Plant-parasitic nematodes were found in 4 of the 12 clades of phylum Nematoda. These nematodes in different clades may have originated independently from their free-living fungivorous ancestors. However, the exact evolutionary process of these parasites is unclear. Here, we sequenced the genome sequence of a migratory plant nematode, Ditylenchus destructor We performed comparative genomics among the free-living nematode, Caenorhabditis elegans and all the plant nematodes with genome sequences available. We found that, compared with C. elegans, the core developmental control processes underwent heavy reduction, though most signal transduction pathways were conserved. We also found D. destructor contained more homologies of the key genes in the above processes than the other plant nematodes. We suggest that Ditylenchus spp. may be an intermediate evolutionary history stage from free-living nematodes that feed on fungi to obligate plant-parasitic nematodes. Based on the facts that D. destructor can feed on fungi and has a relatively short life cycle, and that it has similar features to both C. elegans and sedentary plant-parasitic nematodes from clade 12, we propose it as a new model to study the biology, biocontrol of plant nematodes and the interaction between nematodes and plants.
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Affiliation(s)
- Jinshui Zheng
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China College of Informatics, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Donghai Peng
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Ling Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Hualin Liu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Feng Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Mengci Xu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Shouyong Ju
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Lifang Ruan
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Ming Sun
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
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22
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Giribet G, Edgecombe GD. Current Understanding of Ecdysozoa and its Internal Phylogenetic Relationships. Integr Comp Biol 2017; 57:455-466. [DOI: 10.1093/icb/icx072] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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23
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Kikuchi T, Eves-van den Akker S, Jones JT. Genome Evolution of Plant-Parasitic Nematodes. ANNUAL REVIEW OF PHYTOPATHOLOGY 2017; 55:333-354. [PMID: 28590877 DOI: 10.1146/annurev-phyto-080516-035434] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Plant parasitism has evolved independently on at least four separate occasions in the phylum Nematoda. The application of next-generation sequencing (NGS) to plant-parasitic nematodes has allowed a wide range of genome- or transcriptome-level comparisons, and these have identified genome adaptations that enable parasitism of plants. Current genome data suggest that horizontal gene transfer, gene family expansions, evolution of new genes that mediate interactions with the host, and parasitism-specific gene regulation are important adaptations that allow nematodes to parasitize plants. Sequencing of a larger number of nematode genomes, including plant parasites that show different modes of parasitism or that have evolved in currently unsampled clades, and using free-living taxa as comparators would allow more detailed analysis and a better understanding of the organization of key genes within the genomes. This would facilitate a more complete understanding of the way in which parasitism has shaped the genomes of plant-parasitic nematodes.
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Affiliation(s)
- Taisei Kikuchi
- Division of Parasitology, Faculty of Medicine, University of Miyazaki, Miyazaki 889-1692, Japan;
| | - Sebastian Eves-van den Akker
- Division of Plant Sciences, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, United Kingdom
- Department of Biological Chemistry, The John Innes Centre, Norwich, NR4 7UH, United Kingdom
| | - John T Jones
- Cell and Molecular Sciences Group, Dundee Effector Consortium, James Hutton Institute, Invergowrie, Dundee, DD2 5DA, United Kingdom
- School of Biology, University of St. Andrews, North Haugh, St. Andrews, KY16 9TZ, United Kingdom
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Vieira P, Mowery J, Kilcrease J, Eisenback JD, Kamo K. Characterization of Lilium longiflorum cv. 'Nellie White' Infection with Root-lesion Nematode Pratylenchus penetrans by Bright-field and Transmission Electron Microscopy. J Nematol 2017; 49:2-11. [PMID: 28512372 PMCID: PMC5411250 DOI: 10.21307/jofnem-2017-040] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Indexed: 11/11/2022] Open
Abstract
Lilium longiflorum cv. Nellie White, commonly known as Easter lily, is an important floral crop with an annual wholesale value of over $26 million in the United States. The root-lesion nematode, Pratylenchus penetrans, is a major pest of lily due to the significant root damage it causes. In this study, we investigated the cytological aspects of this plant-nematode interaction using bright-field and transmission electron microscopy. We took advantage of an in vitro culture method to multiply lilies and follow the nematode infection over time. Phenotypic reactions of roots inoculated with P. penetrans were evaluated from 0 to 60 d after nematode infection. Symptom development progressed from initial randomly distributed discrete necrotic areas to advanced necrosis along entire roots of each inoculated plant. A major feature characterizing this susceptible host response to nematode infection was the formation of necrosis, browning, and tissue death involving both root epidermis and cortical cells. Degradation of consecutive cell walls resulted in loss of cell pressure, lack of cytoplasmic integrity, followed by cell death along the intracellular path of the nematode's migration. Pratylenchus penetrans was never seen in the vascular cylinder as the layer of collapsed endodermal cells presumably blocked the progression of nematodes into this area of the roots. This study presents the first detailed cytological characterization of P. penetrans infection of Easter lily plants.
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Affiliation(s)
- Paulo Vieira
- Department of Plant Pathology, Physiology, and Weed Science, Virginia Tech, Blacksburg, VA 24061
- Floral and Nursery Plants Research Unit, U.S. National Arboretum, U.S. Department of Agriculture, Beltsville, MD 20705-2350
| | - Joseph Mowery
- Electron and Confocal Microscopy Unit, U.S. Department of Agriculture, Agricultural Research Service, Beltsville, MD 20705-2350
| | - James Kilcrease
- Floral and Nursery Plants Research Unit, U.S. National Arboretum, U.S. Department of Agriculture, Beltsville, MD 20705-2350
| | - Jonathan D Eisenback
- Department of Plant Pathology, Physiology, and Weed Science, Virginia Tech, Blacksburg, VA 24061
| | - Kathryn Kamo
- Floral and Nursery Plants Research Unit, U.S. National Arboretum, U.S. Department of Agriculture, Beltsville, MD 20705-2350
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Gillet FX, Bournaud C, Antonino de Souza Júnior JD, Grossi-de-Sa MF. Plant-parasitic nematodes: towards understanding molecular players in stress responses. ANNALS OF BOTANY 2017; 119:775-789. [PMID: 28087659 PMCID: PMC5378187 DOI: 10.1093/aob/mcw260] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 10/24/2016] [Indexed: 05/05/2023]
Abstract
BACKGROUND Plant-parasitic nematode interactions occur within a vast molecular plant immunity network. Following initial contact with the host plant roots, plant-parasitic nematodes (PPNs) activate basal immune responses. Defence priming involves the release in the apoplast of toxic molecules derived from reactive species or secondary metabolism. In turn, PPNs must overcome the poisonous and stressful environment at the plant-nematode interface. The ability of PPNs to escape this first line of plant immunity is crucial and will determine its virulence. SCOPE Nematodes trigger crucial regulatory cytoprotective mechanisms, including antioxidant and detoxification pathways. Knowledge of the upstream regulatory components that contribute to both of these pathways in PPNs remains elusive. In this review, we discuss how PPNs probably orchestrate cytoprotection to resist plant immune responses, postulating that it may be derived from ancient molecular mechanisms. The review focuses on two transcription factors, DAF-16 and SKN-1 , which are conserved in the animal kingdom and are central regulators of cell homeostasis and immune function. Both regulate the unfolding protein response and the antioxidant and detoxification pathways. DAF-16 and SKN-1 target a broad spectrum of Caenorhabditis elegans genes coding for numerous protein families present in the secretome of PPNs. Moreover, some regulatory elements of DAF-16 and SKN-1 from C. elegans have already been identified as important genes for PPN infection. CONCLUSION DAF-16 and SKN-1 genes may play a pivotal role in PPNs during parasitism. In the context of their hub status and mode of regulation, we suggest alternative strategies for control of PPNs through RNAi approaches.
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Affiliation(s)
- François-Xavier Gillet
- Embrapa Genetic Resources and Biotechnology, PqEB Final Av. W/5 Norte, CEP 70·770-900, Brasília, DF, Brazil
| | - Caroline Bournaud
- Embrapa Genetic Resources and Biotechnology, PqEB Final Av. W/5 Norte, CEP 70·770-900, Brasília, DF, Brazil
| | | | - Maria Fatima Grossi-de-Sa
- Embrapa Genetic Resources and Biotechnology, PqEB Final Av. W/5 Norte, CEP 70·770-900, Brasília, DF, Brazil
- Catholic University of Brasilia, Brasília-DF, Brazil
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Ali MA, Azeem F, Li H, Bohlmann H. Smart Parasitic Nematodes Use Multifaceted Strategies to Parasitize Plants. FRONTIERS IN PLANT SCIENCE 2017; 8:1699. [PMID: 29046680 PMCID: PMC5632807 DOI: 10.3389/fpls.2017.01699] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Accepted: 09/15/2017] [Indexed: 05/03/2023]
Abstract
Nematodes are omnipresent in nature including many species which are parasitic to plants and cause enormous economic losses in various crops. During the process of parasitism, sedentary phytonematodes use their stylet to secrete effector proteins into the plant cells to induce the development of specialized feeding structures. These effectors are used by the nematodes to develop compatible interactions with plants, partly by mimicking the expression of host genes. Intensive research is going on to investigate the molecular function of these effector proteins in the plants. In this review, we have summarized which physiological and molecular changes occur when endoparasitic nematodes invade the plant roots and how they develop a successful interaction with plants using the effector proteins. We have also mentioned the host genes which are induced by the nematodes for a compatible interaction. Additionally, we discuss how nematodes modulate the reactive oxygen species (ROS) and RNA silencing pathways in addition to post-translational modifications in their own favor for successful parasitism in plants.
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Affiliation(s)
- Muhammad A. Ali
- Department of Plant Pathology, University of Agriculture Faisalabad, Faisalabad, Pakistan
- Centre of Agricultural Biochemistry and Biotechnology, University of Agriculture Faisalabad, Faisalabad, Pakistan
- *Correspondence: Muhammad A. Ali ;
| | - Farrukh Azeem
- Department of Bioinformatics and Biotechnology, Government College University, Faisalabad, Pakistan
| | - Hongjie Li
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Holger Bohlmann
- Division of Plant Protection, Department of Crop Sciences, University of Natural Resources and Life Sciences, Vienna, Vienna, Austria
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Szitenberg A, Cha S, Opperman CH, Bird DM, Blaxter ML, Lunt DH. Genetic Drift, Not Life History or RNAi, Determine Long-Term Evolution of Transposable Elements. Genome Biol Evol 2016; 8:2964-2978. [PMID: 27566762 PMCID: PMC5635653 DOI: 10.1093/gbe/evw208] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/20/2016] [Indexed: 12/11/2022] Open
Abstract
Transposable elements (TEs) are a major source of genome variation across the branches of life. Although TEs may play an adaptive role in their host's genome, they are more often deleterious, and purifying selection is an important factor controlling their genomic loads. In contrast, life history, mating system, GC content, and RNAi pathways have been suggested to account for the disparity of TE loads in different species. Previous studies of fungal, plant, and animal genomes have reported conflicting results regarding the direction in which these genomic features drive TE evolution. Many of these studies have had limited power, however, because they studied taxonomically narrow systems, comparing only a limited number of phylogenetically independent contrasts, and did not address long-term effects on TE evolution. Here, we test the long-term determinants of TE evolution by comparing 42 nematode genomes spanning over 500 million years of diversification. This analysis includes numerous transitions between life history states, and RNAi pathways, and evaluates if these forces are sufficiently persistent to affect the long-term evolution of TE loads in eukaryotic genomes. Although we demonstrate statistical power to detect selection, we find no evidence that variation in these factors influence genomic TE loads across extended periods of time. In contrast, the effects of genetic drift appear to persist and control TE variation among species. We suggest that variation in the tested factors are largely inconsequential to the large differences in TE content observed between genomes, and only by these large-scale comparisons can we distinguish long-term and persistent effects from transient or random changes.
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Affiliation(s)
- Amir Szitenberg
- Evolutionary Biology Group, School of Environmental Sciences, University of Hull, England, United Kingdom The Dead Sea and Arava Science Center, Israel
| | - Soyeon Cha
- Department of Plant Pathology, North Carolina State University
| | | | - David M Bird
- Department of Plant Pathology, North Carolina State University
| | - Mark L Blaxter
- School of Biological Sciences, Institute of Evolutionary Biology, University of Edinburgh, Scotland
| | - David H Lunt
- Evolutionary Biology Group, School of Environmental Sciences, University of Hull, England, United Kingdom
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Fosu-Nyarko J, Jones MGK. Advances in Understanding the Molecular Mechanisms of Root Lesion Nematode Host Interactions. ANNUAL REVIEW OF PHYTOPATHOLOGY 2016; 54:253-78. [PMID: 27296144 DOI: 10.1146/annurev-phyto-080615-100257] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Root lesion nematodes (RLNs) are one of the most economically important groups of plant nematodes. As migratory endoparasites, their presence in roots is less obvious than infestations of sedentary endoparasites; nevertheless, in many instances, they are the major crop pests. With increasing molecular information on nematode parasitism, available data now reflect the differences and, in particular, similarities in lifestyle between migratory and sedentary endoparasites. Far from being unsophisticated compared with sedentary endoparasites, migratory endoparasites are exquisitely suited to their parasitic lifestyle. What they lack in effectors required for induction of permanent feeding sites, they make up for with their versatile host range and their ability to move and feed from new host roots and survive adverse conditions. In this review, we summarize the current molecular data available for RLNs and highlight differences and similarities in effectors and molecular mechanisms between migratory and sedentary endoparasitic nematodes.
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Affiliation(s)
- John Fosu-Nyarko
- Plant Biotechnology Research Group, School of Veterinary and Life Sciences, Western Australian State Agricultural Biotechnology Centre, Murdoch University, Perth, Western Australia 6150, Australia; ,
| | - Michael G K Jones
- Plant Biotechnology Research Group, School of Veterinary and Life Sciences, Western Australian State Agricultural Biotechnology Centre, Murdoch University, Perth, Western Australia 6150, Australia; ,
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Denver DR, Brown AMV, Howe DK, Peetz AB, Zasada IA. Genome Skimming: A Rapid Approach to Gaining Diverse Biological Insights into Multicellular Pathogens. PLoS Pathog 2016; 12:e1005713. [PMID: 27490201 PMCID: PMC4973915 DOI: 10.1371/journal.ppat.1005713] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Dee R. Denver
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
- * E-mail:
| | - Amanda M. V. Brown
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
| | - Dana K. Howe
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
| | - Amy B. Peetz
- USDA-ARS Horticultural Crops Research Laboratory, Corvallis, Oregon, United States of America
| | - Inga A. Zasada
- USDA-ARS Horticultural Crops Research Laboratory, Corvallis, Oregon, United States of America
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Mikhailov K, Slyusarev G, Nikitin M, Logacheva M, Penin A, Aleoshin V, Panchin Y. The Genome of Intoshia linei Affirms Orthonectids as Highly Simplified Spiralians. Curr Biol 2016; 26:1768-1774. [DOI: 10.1016/j.cub.2016.05.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 05/02/2016] [Accepted: 05/03/2016] [Indexed: 11/27/2022]
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Iqbal S, Fosu-Nyarko J, Jones MGK. Genomes of parasitic nematodes (Meloidogyne hapla, Meloidogyne incognita, Ascaris suum and Brugia malayi) have a reduced complement of small RNA interference pathway genes: knockdown can reduce host infectivity of M. incognita. Funct Integr Genomics 2016; 16:441-57. [PMID: 27126863 DOI: 10.1007/s10142-016-0495-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 04/08/2016] [Accepted: 04/18/2016] [Indexed: 12/15/2022]
Abstract
The discovery of RNA interference (RNAi) as an endogenous mechanism of gene regulation in a range of eukaryotes has resulted in its extensive use as a tool for functional genomic studies. It is important to study the mechanisms which underlie this phenomenon in different organisms, and in particular to understand details of the effectors that modulate its effectiveness. The aim of this study was to identify and compare genomic sequences encoding genes involved in the RNAi pathway of four parasitic nematodes: the plant parasites Meloidogyne hapla and Meloidogyne incognita and the animal parasites Ascaris suum and Brugia malayi because full genomic sequences were available-in relation to those of the model nematode Caenorhabditis elegans. The data generated was then used to identify some potential targets for control of the root knot nematode, M. incognita. Of the 84 RNAi pathway genes of C. elegans used as model in this study, there was a 42-53 % reduction in the number of effectors in the parasitic nematodes indicating substantial differences in the pathway between species. A gene each from six functional groups of the RNAi pathway of M. incognita was downregulated using in vitro RNAi, and depending on the gene (drh-3, tsn-1, rrf-1, xrn-2, mut-2 and alg-1), subsequent plant infection was reduced by up to 44 % and knockdown of some genes (i.e. drh-3, mut-2) also resulted in abnormal nematode development. The information generated here will contribute to defining targets for more robust nematode control using the RNAi technology.
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Affiliation(s)
- Sadia Iqbal
- Plant Biotechnology Research Group, WA State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, WA, 6150, Australia.
| | - John Fosu-Nyarko
- Plant Biotechnology Research Group, WA State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, WA, 6150, Australia
| | - Michael G K Jones
- Plant Biotechnology Research Group, WA State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, WA, 6150, Australia
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Noon JB, Baum TJ. Horizontal gene transfer of acetyltransferases, invertases and chorismate mutases from different bacteria to diverse recipients. BMC Evol Biol 2016; 16:74. [PMID: 27068610 PMCID: PMC4828791 DOI: 10.1186/s12862-016-0651-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Accepted: 04/05/2016] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Hoplolaimina plant-parasitic nematodes (PPN) are a lineage of animals with many documented cases of horizontal gene transfer (HGT). In a recent study, we reported on three likely HGT candidate genes in the soybean cyst nematode Heterodera glycines, all of which encode secreted candidate effectors with putative functions in the host plant. Hg-GLAND1 is a putative GCN5-related N-acetyltransferase (GNAT), Hg-GLAND13 is a putative invertase (INV), and Hg-GLAND16 is a putative chorismate mutase (CM), and blastp searches of the non-redundant database resulted in highest similarity to bacterial sequences. Here, we searched nematode and non-nematode sequence databases to identify all the nematodes possible that contain these three genes, and to formulate hypotheses about when they most likely appeared in the phylum Nematoda. We then performed phylogenetic analyses combined with model selection tests of alternative models of sequence evolution to determine whether these genes were horizontally acquired from bacteria. RESULTS Mining of nematode sequence databases determined that GNATs appeared in Hoplolaimina PPN late in evolution, while both INVs and CMs appeared before the radiation of the Hoplolaimina suborder. Also, Hoplolaimina GNATs, INVs and CMs formed well-supported clusters with different rhizosphere bacteria in the phylogenetic trees, and the model selection tests greatly supported models of HGT over descent via common ancestry. Surprisingly, the phylogenetic trees also revealed additional, well-supported clusters of bacterial GNATs, INVs and CMs with diverse eukaryotes and archaea. There were at least eleven and eight well-supported clusters of GNATs and INVs, respectively, from different bacteria with diverse eukaryotes and archaea. Though less frequent, CMs from different bacteria formed supported clusters with multiple different eukaryotes. Moreover, almost all individual clusters containing bacteria and eukaryotes or archaea contained species that inhabit very similar niches. CONCLUSIONS GNATs were horizontally acquired late in Hoplolaimina PPN evolution from bacteria most similar to the saprophytic and plant-pathogenic actinomycetes. INVs and CMs were horizontally acquired from bacteria most similar to rhizobacteria and Burkholderia soil bacteria, respectively, before the radiation of Hoplolaimina. Also, these three gene groups appear to have been frequent subjects of HGT from different bacteria to numerous, diverse lineages of eukaryotes and archaea, which suggests that these genes may confer important evolutionary advantages to many taxa. In the case of Hoplolaimina PPN, this advantage likely was an improved ability to parasitize plants.
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Affiliation(s)
- Jason B. Noon
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA 50011 USA
| | - Thomas J. Baum
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA 50011 USA
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Fosu-Nyarko J, Nicol P, Naz F, Gill R, Jones MGK. Analysis of the Transcriptome of the Infective Stage of the Beet Cyst Nematode, H. schachtii. PLoS One 2016; 11:e0147511. [PMID: 26824923 PMCID: PMC4733053 DOI: 10.1371/journal.pone.0147511] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 01/05/2016] [Indexed: 01/08/2023] Open
Abstract
The beet cyst nematode, Heterodera schachtii, is a major root pest that significantly impacts the yield of sugar beet, brassicas and related species. There has been limited molecular characterisation of this important plant pathogen: to identify target genes for its control the transcriptome of the pre-parasitic J2 stage of H. schachtii was sequenced using Roche GS FLX. Ninety seven percent of reads (i.e., 387,668) with an average PHRED score > 22 were assembled with CAP3 and CLC Genomics Workbench into 37,345 and 47,263 contigs, respectively. The transcripts were annotated by comparing with gene and genomic sequences of other nematodes and annotated proteins on public databases. The annotated transcripts were much more similar to sequences of Heterodera glycines than to those of Globodera pallida and root knot nematodes (Meloidogyne spp.). Analysis of these transcripts showed that a subset of 2,918 transcripts was common to free-living and plant parasitic nematodes suggesting that this subset is involved in general nematode metabolism and development. A set of 148 contigs and 183 singletons encoding putative homologues of effectors previously characterised for plant parasitic nematodes were also identified: these are known to be important for parasitism of host plants during migration through tissues or feeding from cells or are thought to be involved in evasion or modulation of host defences. In addition, the presence of sequences from a nematode virus is suggested. The sequencing and annotation of this transcriptome significantly adds to the genetic data available for H. schachtii, and identifies genes primed to undertake required roles in the critical pre-parasitic and early post-parasitic J2 stages. These data provide new information for identifying potential gene targets for future protection of susceptible crops against H. schachtii.
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Affiliation(s)
- John Fosu-Nyarko
- Plant Biotechnology Research Group, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, Australia
- NemGenix Pty Ltd, Western Australian State Agricultural Biotechnology Centre, Murdoch University, Perth, Australia
- * E-mail: ; (JFN); (MGKJ)
| | - Paul Nicol
- Plant Biotechnology Research Group, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, Australia
| | - Fareeha Naz
- Plant Biotechnology Research Group, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, Australia
| | - Reetinder Gill
- Plant Biotechnology Research Group, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, Australia
| | - Michael G. K. Jones
- Plant Biotechnology Research Group, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, Australia
- * E-mail: ; (JFN); (MGKJ)
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Vieira P, Eves-van den Akker S, Verma R, Wantoch S, Eisenback JD, Kamo K. The Pratylenchus penetrans Transcriptome as a Source for the Development of Alternative Control Strategies: Mining for Putative Genes Involved in Parasitism and Evaluation of in planta RNAi. PLoS One 2015; 10:e0144674. [PMID: 26658731 PMCID: PMC4684371 DOI: 10.1371/journal.pone.0144674] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 11/20/2015] [Indexed: 11/25/2022] Open
Abstract
The root lesion nematode Pratylenchus penetrans is considered one of the most economically important species within the genus. Host range studies have shown that nearly 400 plant species can be parasitized by this species. To obtain insight into the transcriptome of this migratory plant-parasitic nematode, we used Illumina mRNA sequencing analysis of a mixed population, as well as nematode reads detected in infected soybean roots 3 and 7 days after nematode infection. Over 140 million paired end reads were obtained for this species, and de novo assembly resulted in a total of 23,715 transcripts. Homology searches showed significant hit matches to 58% of the total number of transcripts using different protein and EST databases. In general, the transcriptome of P. penetrans follows common features reported for other root lesion nematode species. We also explored the efficacy of RNAi, delivered from the host, as a strategy to control P. penetrans, by targeted knock-down of selected nematode genes. Different comparisons were performed to identify putative nematode genes with a role in parasitism, resulting in the identification of transcripts with similarities to other nematode parasitism genes. Focusing on the predicted nematode secreted proteins found in this transcriptome, we observed specific members to be up-regulated at the early time points of infection. In the present study, we observed an enrichment of predicted secreted proteins along the early time points of parasitism by this species, with a significant number being pioneer candidate genes. A representative set of genes examined using RT-PCR confirms their expression during the host infection. The expression patterns of the different candidate genes raise the possibility that they might be involved in critical steps of P. penetrans parasitism. This analysis sheds light on the transcriptional changes that accompany plant infection by P. penetrans, and will aid in identifying potential gene targets for selection and use to design effective control strategies against root lesion nematodes.
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Affiliation(s)
- Paulo Vieira
- Dept. of Plant Pathology, Physiology, and Weed Science, Virginia Tech, Blacksburg, VA, 24061, United States of America
- Floral and Nursery Plants Research Unit, U.S. National Arboretum, U.S. Department of Agriculture, Beltsville, MD, 20705–2350, United States of America
| | | | - Ruchi Verma
- Floral and Nursery Plants Research Unit, U.S. National Arboretum, U.S. Department of Agriculture, Beltsville, MD, 20705–2350, United States of America
| | - Sarah Wantoch
- Floral and Nursery Plants Research Unit, U.S. National Arboretum, U.S. Department of Agriculture, Beltsville, MD, 20705–2350, United States of America
| | - Jonathan D. Eisenback
- Dept. of Plant Pathology, Physiology, and Weed Science, Virginia Tech, Blacksburg, VA, 24061, United States of America
| | - Kathryn Kamo
- Floral and Nursery Plants Research Unit, U.S. National Arboretum, U.S. Department of Agriculture, Beltsville, MD, 20705–2350, United States of America
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Abstract
The Myxozoa comprise over 2,000 species of microscopic obligate parasites that use both invertebrate and vertebrate hosts as part of their life cycle. Although the evolutionary origin of myxozoans has been elusive, a close relationship with cnidarians, a group that includes corals, sea anemones, jellyfish, and hydroids, is supported by some phylogenetic studies and the observation that the distinctive myxozoan structure, the polar capsule, is remarkably similar to the stinging structures (nematocysts) in cnidarians. To gain insight into the extreme evolutionary transition from a free-living cnidarian to a microscopic endoparasite, we analyzed genomic and transcriptomic assemblies from two distantly related myxozoan species, Kudoa iwatai and Myxobolus cerebralis, and compared these to the transcriptome and genome of the less reduced cnidarian parasite, Polypodium hydriforme. A phylogenomic analysis, using for the first time to our knowledge, a taxonomic sampling that represents the breadth of myxozoan diversity, including four newly generated myxozoan assemblies, confirms that myxozoans are cnidarians and are a sister taxon to P. hydriforme. Estimations of genome size reveal that myxozoans have one of the smallest reported animal genomes. Gene enrichment analyses show depletion of expressed genes in categories related to development, cell differentiation, and cell-cell communication. In addition, a search for candidate genes indicates that myxozoans lack key elements of signaling pathways and transcriptional factors important for multicellular development. Our results suggest that the degeneration of the myxozoan body plan from a free-living cnidarian to a microscopic parasitic cnidarian was accompanied by extreme reduction in genome size and gene content.
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