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Vo NNT, Yang A, Leesutthiphonchai W, Liu Y, Hughes TR, Judelson HS. Transcription factor binding specificities of the oomycete Phytophthora infestans reflect conserved and divergent evolutionary patterns and predict function. BMC Genomics 2024; 25:710. [PMID: 39044130 PMCID: PMC11267843 DOI: 10.1186/s12864-024-10630-6] [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: 02/13/2024] [Accepted: 07/17/2024] [Indexed: 07/25/2024] Open
Abstract
BACKGROUND Identifying the DNA-binding specificities of transcription factors (TF) is central to understanding gene networks that regulate growth and development. Such knowledge is lacking in oomycetes, a microbial eukaryotic lineage within the stramenopile group. Oomycetes include many important plant and animal pathogens such as the potato and tomato blight agent Phytophthora infestans, which is a tractable model for studying life-stage differentiation within the group. RESULTS Mining of the P. infestans genome identified 197 genes encoding proteins belonging to 22 TF families. Their chromosomal distribution was consistent with family expansions through unequal crossing-over, which were likely ancient since each family had similar sizes in most oomycetes. Most TFs exhibited dynamic changes in RNA levels through the P. infestans life cycle. The DNA-binding preferences of 123 proteins were assayed using protein-binding oligonucleotide microarrays, which succeeded with 73 proteins from 14 families. Binding sites predicted for representatives of the families were validated by electrophoretic mobility shift or chromatin immunoprecipitation assays. Consistent with the substantial evolutionary distance of oomycetes from traditional model organisms, only a subset of the DNA-binding preferences resembled those of human or plant orthologs. Phylogenetic analyses of the TF families within P. infestans often discriminated clades with canonical and novel DNA targets. Paralogs with similar binding preferences frequently had distinct patterns of expression suggestive of functional divergence. TFs were predicted to either drive life stage-specific expression or serve as general activators based on the representation of their binding sites within total or developmentally-regulated promoters. This projection was confirmed for one TF using synthetic and mutated promoters fused to reporter genes in vivo. CONCLUSIONS We established a large dataset of binding specificities for P. infestans TFs, representing the first in the stramenopile group. This resource provides a basis for understanding transcriptional regulation by linking TFs with their targets, which should help delineate the molecular components of processes such as sporulation and host infection. Our work also yielded insight into TF evolution during the eukaryotic radiation, revealing both functional conservation as well as diversification across kingdoms.
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Affiliation(s)
- Nguyen N T Vo
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, 92521, USA
| | - Ally Yang
- Department of Molecular Genetics and Donnelly Center, University of Toronto, Toronto, ON, M5S 3E1, Canada
| | - Wiphawee Leesutthiphonchai
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, 92521, USA
- Current address: Department of Plant Pathology, Faculty of Agriculture, Kasetsart University, Bangkok, 10900, Thailand
| | - Yulong Liu
- Department of Molecular Genetics and Donnelly Center, University of Toronto, Toronto, ON, M5S 3E1, Canada
| | - Timothy R Hughes
- Department of Molecular Genetics and Donnelly Center, University of Toronto, Toronto, ON, M5S 3E1, Canada
| | - Howard S Judelson
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, 92521, USA.
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2
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Záhonová K, Low RS, Warren CJ, Cantoni D, Herman EK, Yiangou L, Ribeiro CA, Phanprasert Y, Brown IR, Rueckert S, Baker NL, Tachezy J, Betts EL, Gentekaki E, van der Giezen M, Clark CG, Jackson AP, Dacks JB, Tsaousis AD. Evolutionary analysis of cellular reduction and anaerobicity in the hyper-prevalent gut microbe Blastocystis. Curr Biol 2023:S0960-9822(23)00620-6. [PMID: 37267944 DOI: 10.1016/j.cub.2023.05.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 03/22/2023] [Accepted: 05/11/2023] [Indexed: 06/04/2023]
Abstract
Blastocystis is the most prevalent microbial eukaryote in the human and animal gut, yet its role as commensal or parasite is still under debate. Blastocystis has clearly undergone evolutionary adaptation to the gut environment and possesses minimal cellular compartmentalization, reduced anaerobic mitochondria, no flagella, and no reported peroxisomes. To address this poorly understood evolutionary transition, we have taken a multi-disciplinary approach to characterize Proteromonas lacertae, the closest canonical stramenopile relative of Blastocystis. Genomic data reveal an abundance of unique genes in P. lacertae but also reductive evolution of the genomic complement in Blastocystis. Comparative genomic analysis sheds light on flagellar evolution, including 37 new candidate components implicated with mastigonemes, the stramenopile morphological hallmark. The P. lacertae membrane-trafficking system (MTS) complement is only slightly more canonical than that of Blastocystis, but notably, we identified that both organisms encode the complete enigmatic endocytic TSET complex, a first for the entire stramenopile lineage. Investigation also details the modulation of mitochondrial composition and metabolism in both P. lacertae and Blastocystis. Unexpectedly, we identify in P. lacertae the most reduced peroxisome-derived organelle reported to date, which leads us to speculate on a mechanism of constraint guiding the dynamics of peroxisome-mitochondrion reductive evolution on the path to anaerobiosis. Overall, these analyses provide a launching point to investigate organellar evolution and reveal in detail the evolutionary path that Blastocystis has taken from a canonical flagellated protist to the hyper-divergent and hyper-prevalent animal and human gut microbe.
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Affiliation(s)
- Kristína Záhonová
- Division of Infectious Diseases, Department of Medicine, University of Alberta, 1-124 Clinical Sciences Building, 11350-83 Avenue, Edmonton T6G 2G3, Canada; Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovská 1160/31, České Budějovice (Budweis) 370 05, Czech Republic; Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, Vestec 252 50, Czech Republic; Life Science Research Centre, Department of Biology and Ecology, Faculty of Science, University of Ostrava, Chittussiho 10, Ostrava 710 00, Czech Republic
| | - Ross S Low
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK; The Earlham Institute, Norwich Research Park, Norwich NR4 7UZ, UK
| | - Christopher J Warren
- Laboratory of Molecular & Evolutionary Parasitology, RAPID Group, School of Biosciences, University of Kent, Giles Lane, Stacey Building, Canterbury, Kent CT2 7NJ, UK
| | - Diego Cantoni
- Laboratory of Molecular & Evolutionary Parasitology, RAPID Group, School of Biosciences, University of Kent, Giles Lane, Stacey Building, Canterbury, Kent CT2 7NJ, UK
| | - Emily K Herman
- Division of Infectious Diseases, Department of Medicine, University of Alberta, 1-124 Clinical Sciences Building, 11350-83 Avenue, Edmonton T6G 2G3, Canada; Department of Agricultural, Food, and Nutritional Science, Faculty of Agricultural, Life, and Environmental Sciences, University of Alberta, 2-31 General Services Building, Edmonton, AB T6G 2H1, Canada
| | - Lyto Yiangou
- Laboratory of Molecular & Evolutionary Parasitology, RAPID Group, School of Biosciences, University of Kent, Giles Lane, Stacey Building, Canterbury, Kent CT2 7NJ, UK
| | - Cláudia A Ribeiro
- Laboratory of Molecular & Evolutionary Parasitology, RAPID Group, School of Biosciences, University of Kent, Giles Lane, Stacey Building, Canterbury, Kent CT2 7NJ, UK
| | - Yasinee Phanprasert
- Division of Infectious Diseases, Department of Medicine, University of Alberta, 1-124 Clinical Sciences Building, 11350-83 Avenue, Edmonton T6G 2G3, Canada; School of Science, Mae Fah Luang Universit, 333 Moo 1, T. Tasud, Muang District, Chiang Rai 57100, Thailand
| | - Ian R Brown
- Laboratory of Molecular & Evolutionary Parasitology, RAPID Group, School of Biosciences, University of Kent, Giles Lane, Stacey Building, Canterbury, Kent CT2 7NJ, UK
| | - Sonja Rueckert
- School of Applied Sciences, Sighthill Campus, Room 3.B.36, Edinburgh EH11 4BN, Scotland; Faculty of Biology, AG Eukaryotische Mikrobiologie, Universitätsstrasse 5, S05 R04 H83, Essen 45141, Germany
| | - Nicola L Baker
- Laboratory of Molecular & Evolutionary Parasitology, RAPID Group, School of Biosciences, University of Kent, Giles Lane, Stacey Building, Canterbury, Kent CT2 7NJ, UK
| | - Jan Tachezy
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, Vestec 252 50, Czech Republic
| | - Emma L Betts
- Laboratory of Molecular & Evolutionary Parasitology, RAPID Group, School of Biosciences, University of Kent, Giles Lane, Stacey Building, Canterbury, Kent CT2 7NJ, UK; School of Applied Sciences, Sighthill Campus, Room 3.B.36, Edinburgh EH11 4BN, Scotland
| | - Eleni Gentekaki
- School of Science, Mae Fah Luang Universit, 333 Moo 1, T. Tasud, Muang District, Chiang Rai 57100, Thailand; Gut Microbiome Research Group, Mae Fah Luang University, 333 Moo 1, T. Tasud, Muang District, Chiang Rai 57100, Thailand
| | - Mark van der Giezen
- Department of Chemistry, Bioscience and Environmental Engineering, University of Stavanger Richard Johnsens Gate 4, 4021 Stavanger, Norway; Biosciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - C Graham Clark
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Andrew P Jackson
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Joel B Dacks
- Division of Infectious Diseases, Department of Medicine, University of Alberta, 1-124 Clinical Sciences Building, 11350-83 Avenue, Edmonton T6G 2G3, Canada; Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovská 1160/31, České Budějovice (Budweis) 370 05, Czech Republic; Centre for Life's Origin and Evolution, Division of Biosciences, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK.
| | - Anastasios D Tsaousis
- Laboratory of Molecular & Evolutionary Parasitology, RAPID Group, School of Biosciences, University of Kent, Giles Lane, Stacey Building, Canterbury, Kent CT2 7NJ, UK.
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Kasteel M, Ketelaar T, Govers F. Fatal attraction: How Phytophthora zoospores find their host. Semin Cell Dev Biol 2023; 148-149:13-21. [PMID: 36792439 DOI: 10.1016/j.semcdb.2023.01.014] [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: 12/14/2022] [Revised: 01/30/2023] [Accepted: 01/31/2023] [Indexed: 02/15/2023]
Abstract
Oomycete plant pathogens, such as Phytophthora and Pythium species produce motile dispersal agents called zoospores that actively target host plants. Zoospores are exceptional in their ability to display taxis to chemical, electrical and physical cues to navigate the phyllosphere and reach stomata, wound sites and roots. Many components of root exudates have been shown attractive or repulsive to zoospores. Although some components possess very strong attractiveness, it seems that especially the mix of components exuded by the primary host is most attractive to zoospores. Zoospores actively approach attractants with swimming behaviour reminiscent of other microswimmers. To achieve a unified description of zoospore behaviour when sensing an attractant, we propose the following terms for the successive stages of the homing response: reorientation, approaching, retention and settling. How zoospores sense and process attractants is poorly understood but likely involves signal perception via cell surface receptors. Since zoospores are important for infection, undermining their activity by luring attractants or blocking receptors seem promising strategies for disease control.
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Affiliation(s)
- Michiel Kasteel
- Laboratory of Phytopathology, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB Wageningen, the Netherlands; Laboratory of Cell Biology, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB Wageningen, the Netherlands.
| | - Tijs Ketelaar
- Laboratory of Cell Biology, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB Wageningen, the Netherlands.
| | - Francine Govers
- Laboratory of Phytopathology, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB Wageningen, the Netherlands.
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4
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Xue X, Suvorov A, Fujimoto S, Dilman AR, Adams BJ. Genome analysis of Plectus murrayi, a nematode from continental Antarctica. G3-GENES GENOMES GENETICS 2021; 11:6044189. [PMID: 33561244 PMCID: PMC8022722 DOI: 10.1093/g3journal/jkaa045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 12/08/2020] [Indexed: 01/23/2023]
Abstract
Plectus murrayi is one of the most common and locally abundant invertebrates of continental Antarctic ecosystems. Because it is readily cultured on artificial medium in the laboratory and highly tolerant to an extremely harsh environment, P. murrayi is emerging as a model organism for understanding the evolutionary origin and maintenance of adaptive responses to multiple environmental stressors, including freezing and desiccation. The de novo assembled genome of P. murrayi contains 225.741 million base pairs and a total of 14,689 predicted genes. Compared to Caenorhabditis elegans, the architectural components of P. murrayi are characterized by a lower number of protein-coding genes, fewer transposable elements, but more exons, than closely related taxa from less harsh environments. We compared the transcriptomes of lab-reared P. murrayi with wild-caught P. murrayi and found genes involved in growth and cellular processing were up-regulated in lab-cultured P. murrayi, while a few genes associated with cellular metabolism and freeze tolerance were expressed at relatively lower levels. Preliminary comparative genomic and transcriptomic analyses suggest that the observed constraints on P. murrayi genome architecture and functional gene expression, including genome decay and intron retention, may be an adaptive response to persisting in a biotically simplified, yet consistently physically harsh environment.
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Affiliation(s)
- Xia Xue
- Precision Medicine Center, Academy of Medical Sciences, Zhengzhou University, Zhengzhou 450000, China.,Department of Biology, Evolutionary Ecology Laboratories, and Monte L. Bean Museum, Brigham Young University, Provo, UT, USA
| | - Anton Suvorov
- Department of Biology, Evolutionary Ecology Laboratories, and Monte L. Bean Museum, Brigham Young University, Provo, UT, USA
| | - Stanley Fujimoto
- Department of Computer Science, Brigham Young University, Provo, UT, USA
| | - Adler R Dilman
- Department of Nematology, University of California, Riverside, CA, USA
| | - Byron J Adams
- Department of Biology, Evolutionary Ecology Laboratories, and Monte L. Bean Museum, Brigham Young University, Provo, UT, USA
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5
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Bassani I, Larousse M, Tran QD, Attard A, Galiana E. Phytophthora zoospores: From perception of environmental signals to inoculum formation on the host-root surface. Comput Struct Biotechnol J 2020; 18:3766-3773. [PMID: 33304469 PMCID: PMC7718214 DOI: 10.1016/j.csbj.2020.10.045] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 10/29/2020] [Accepted: 10/31/2020] [Indexed: 12/13/2022] Open
Abstract
To explore moist soils and to target host plants, phytopathogenic Phytophthora species utilize the sensory and propulsion capabilities of the biflagellate unicellular zoospores they produce. Zoospore motion and interactions with the microenvironment are of primary importance for Phytophthora physiology. These are also of critical significance for plant pathology in early infection sequential events and their regulation: the directed zoospore migration toward the host, the local aggregation and adhesion at the host penetration site. In the soil, these early events preceding the root colonization are orchestrated by guidance factors, released from the soil particles in water films, or emitted within microbiota and by host plants. This signaling network is perceived by zoospores and results in coordinated behavior and preferential localization in the rhizosphere. Recent computational and structural studies suggest that rhizospheric ion and plant metabolite sensing is a key determinant in driving zoospore motion, orientation and aggregation. To reach their target, zoospores respond to various molecular, chemical and electrical stimuli. However, it is not yet clear how these signals are generated in local soil niches and which gene functions govern the sensing and subsequent responses of zoospores. Here we review studies on the soil, microbial and host-plant factors that drive zoospore motion, as well as the adaptations governing zoospore behavior. We propose several research directions that could be explored to characterize the role of zoospore microbial ecology in disease.
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Affiliation(s)
- Ilaria Bassani
- Université Côte d'Azur, INRAE, CNRS, ISA, Sophia Antipolis 06903, France
| | - Marie Larousse
- Université Côte d'Azur, INRAE, CNRS, ISA, Sophia Antipolis 06903, France
| | - Quang D Tran
- Université Côte d'Azur, CNRS, UMR 7010, Institut de Physique de Nice, Nice 06108, France
| | - Agnès Attard
- Université Côte d'Azur, INRAE, CNRS, ISA, Sophia Antipolis 06903, France
| | - Eric Galiana
- Université Côte d'Azur, INRAE, CNRS, ISA, Sophia Antipolis 06903, France
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6
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Thines M, Sharma R, Rodenburg SYA, Gogleva A, Judelson HS, Xia X, van den Hoogen J, Kitner M, Klein J, Neilen M, de Ridder D, Seidl MF, van den Ackerveken G, Govers F, Schornack S, Studholme DJ. The Genome of Peronospora belbahrii Reveals High Heterozygosity, a Low Number of Canonical Effectors, and TC-Rich Promoters. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2020; 33:742-753. [PMID: 32237964 DOI: 10.1094/mpmi-07-19-0211-r] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Along with Plasmopara destructor, Peronosopora belbahrii has arguably been the economically most important newly emerging downy mildew pathogen of the past two decades. Originating from Africa, it has started devastating basil production throughout the world, most likely due to the distribution of infested seed material. Here, we present the genome of this pathogen and results from comparisons of its genomic features to other oomycetes. The assembly of the nuclear genome was around 35.4 Mbp in length, with an N50 scaffold length of around 248 kbp and an L50 scaffold count of 46. The circular mitochondrial genome consisted of around 40.1 kbp. From the repeat-masked genome, 9,049 protein-coding genes were predicted, out of which 335 were predicted to have extracellular functions, representing the smallest secretome so far found in peronosporalean oomycetes. About 16% of the genome consists of repetitive sequences, and, based on simple sequence repeat regions, we provide a set of microsatellites that could be used for population genetic studies of P. belbahrii. P. belbahrii has undergone a high degree of convergent evolution with other obligate parasitic pathogen groups, reflecting its obligate biotrophic lifestyle. Features of its secretome, signaling networks, and promoters are presented, and some patterns are hypothesized to reflect the high degree of host specificity in Peronospora species. In addition, we suggest the presence of additional virulence factors apart from classical effector classes that are promising candidates for future functional studies.
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Affiliation(s)
- Marco Thines
- Institute of Ecology, Evolution and Diversity, Goethe University, Max-von-Laue-Str. 9, 60323 Frankfurt (Main), Germany
- Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, 60325 Frankfurt (Main), Germany
- Integrative Fungal Research (IPF) and Translational Biodiversity Genomics (TBG), Georg-Voigt-Str. 14-16, 60325 Frankfurt (Main), Germany
| | - Rahul Sharma
- Institute of Ecology, Evolution and Diversity, Goethe University, Max-von-Laue-Str. 9, 60323 Frankfurt (Main), Germany
- Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, 60325 Frankfurt (Main), Germany
- Integrative Fungal Research (IPF) and Translational Biodiversity Genomics (TBG), Georg-Voigt-Str. 14-16, 60325 Frankfurt (Main), Germany
| | - Sander Y A Rodenburg
- Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
- Bioinformatics Group, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Anna Gogleva
- University of Cambridge, Sainsbury Laboratory, 47 Bateman Street, Cambridge, CB2 1LR, U.K
| | - Howard S Judelson
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA 92521 U.S.A
| | - Xiaojuan Xia
- Institute of Ecology, Evolution and Diversity, Goethe University, Max-von-Laue-Str. 9, 60323 Frankfurt (Main), Germany
- Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, 60325 Frankfurt (Main), Germany
| | - Johan van den Hoogen
- Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Miloslav Kitner
- Department of Botany, Faculty of Science, Palacký University Olomouc, Šlechtitelů 27, 78371 Olomouc, Czech Republic
| | - Joël Klein
- Plant-Microbe Interactions, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Manon Neilen
- Plant-Microbe Interactions, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Dick de Ridder
- Bioinformatics Group, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Michael F Seidl
- Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Guido van den Ackerveken
- Plant-Microbe Interactions, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Francine Govers
- Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Sebastian Schornack
- University of Cambridge, Sainsbury Laboratory, 47 Bateman Street, Cambridge, CB2 1LR, U.K
| | - David J Studholme
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Stocker Road, Exeter EX4 4QD, U.K
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7
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Abstract
The oomycetes are a class of ubiquitous, filamentous microorganisms that include some of the biggest threats to global food security and natural ecosystems. Within the oomycete class are highly diverse species that infect a broad range of animals and plants. Some of the most destructive plant pathogens are oomycetes, such as Phytophthora infestans, the agent of potato late blight and the cause of the Irish famine. Recent years have seen a dramatic increase in the number of sequenced oomycete genomes. Here we review the latest developments in oomycete genomics and some of the important insights that have been gained. Coupled with proteomic and transcriptomic analyses, oomycete genome sequences have revealed tremendous insights into oomycete biology, evolution, genome organization, mechanisms of infection, and metabolism. We also present an updated phylogeny of the oomycete class using a phylogenomic approach based on the 65 oomycete genomes that are currently available.
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Affiliation(s)
- Jamie McGowan
- Genome Evolution Laboratory, Department of Biology, Maynooth University, Maynooth, County Kildare, Ireland; Kathleen Lonsdale Institute for Human Health Research, Maynooth University, Maynooth, County Kildare, Ireland
| | - David A Fitzpatrick
- Genome Evolution Laboratory, Department of Biology, Maynooth University, Maynooth, County Kildare, Ireland; Kathleen Lonsdale Institute for Human Health Research, Maynooth University, Maynooth, County Kildare, Ireland.
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8
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Leesutthiphonchai W, Judelson HS. Phytophthora infestans Sporangia Produced in Artificial Media and Plant Lesions Have Subtly Divergent Transcription Profiles but Equivalent Infection Potential and Aggressiveness. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2019; 32:1077-1087. [PMID: 30908943 DOI: 10.1094/mpmi-12-18-0349-ta] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Sporangia of the potato late blight agent Phytophthora infestans are often used in studies of pathogen biology and plant responses to infection. Investigations of spore biology can be challenging in oomycetes because their sporangia are physiologically active and change in response to environmental factors and aging. Whether sporangia from artificial media and plant lesions are functionally equivalent has been a topic of debate. To address these issues, we compared the transcriptomes and infection ability of sporangia from rye-sucrose media, potato and tomato leaflets, and potato tubers. Small differences were observed between the mRNA profiles of sporangia from all sources, including variation in genes encoding metabolic enzymes, cell-wall-degrading enzymes, and ABC transporters. Small differences in sporangia age also resulted in variation in the transcriptome. Taking care to use sporangia of similar maturity, we observed that those sourced from media or plant lesions had similar rates of zoospore release and cyst germination. There were also no differences in infection rates or aggressiveness on leaflets, based on single-spore inoculation assays. Such results are discordant with those of a recent publication in this journal. Nevertheless, we conclude that sporangia from plant and media cultures are functionally similar and emphasize the importance of using "best practices" in experiments with sporangia to obtain reliable results.
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Affiliation(s)
| | - Howard S Judelson
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA 92521, U.S.A
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9
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Fletcher K, Gil J, Bertier LD, Kenefick A, Wood KJ, Zhang L, Reyes-Chin-Wo S, Cavanaugh K, Tsuchida C, Wong J, Michelmore R. Genomic signatures of heterokaryosis in the oomycete pathogen Bremia lactucae. Nat Commun 2019; 10:2645. [PMID: 31201315 PMCID: PMC6570648 DOI: 10.1038/s41467-019-10550-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 05/14/2019] [Indexed: 12/26/2022] Open
Abstract
Lettuce downy mildew caused by Bremia lactucae is the most important disease of lettuce globally. This oomycete is highly variable and rapidly overcomes resistance genes and fungicides. The use of multiple read types results in a high-quality, near-chromosome-scale, consensus assembly. Flow cytometry plus resequencing of 30 field isolates, 37 sexual offspring, and 19 asexual derivatives from single multinucleate sporangia demonstrates a high incidence of heterokaryosis in B. lactucae. Heterokaryosis has phenotypic consequences on fitness that may include an increased sporulation rate and qualitative differences in virulence. Therefore, selection should be considered as acting on a population of nuclei within coenocytic mycelia. This provides evolutionary flexibility to the pathogen enabling rapid adaptation to different repertoires of host resistance genes and other challenges. The advantages of asexual persistence of heterokaryons may have been one of the drivers of selection that resulted in the loss of uninucleate zoospores in multiple downy mildews.
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Affiliation(s)
- Kyle Fletcher
- Genome Center, University of California, Davis, CA, 95616, USA
| | - Juliana Gil
- Genome Center, University of California, Davis, CA, 95616, USA
- Plant Pathology Graduate Group, University of California, Davis, CA, 95616, USA
| | - Lien D Bertier
- Genome Center, University of California, Davis, CA, 95616, USA
| | - Aubrey Kenefick
- Genome Center, University of California, Davis, CA, 95616, USA
| | - Kelsey J Wood
- Genome Center, University of California, Davis, CA, 95616, USA
- Integrated Genetics and Genomics Graduate Group, University of California, Davis, CA, 95616, USA
| | - Lin Zhang
- Genome Center, University of California, Davis, CA, 95616, USA
| | - Sebastian Reyes-Chin-Wo
- Genome Center, University of California, Davis, CA, 95616, USA
- Integrated Genetics and Genomics Graduate Group, University of California, Davis, CA, 95616, USA
- Bayer Crop Science, 37437 CA-16, Woodland, CA, 95695, USA
| | - Keri Cavanaugh
- Genome Center, University of California, Davis, CA, 95616, USA
| | - Cayla Tsuchida
- Genome Center, University of California, Davis, CA, 95616, USA
- Plant Pathology Graduate Group, University of California, Davis, CA, 95616, USA
- Arcadia Biosciences, Davis, CA, 95616, USA
| | - Joan Wong
- Genome Center, University of California, Davis, CA, 95616, USA
- Plant Biology Graduate Group, University of California, Davis, CA, 95616, USA
- Pacific Biosciences of California, Inc., Menlo Park, CA, 94025, USA
| | - Richard Michelmore
- Genome Center, University of California, Davis, CA, 95616, USA.
- Departments of Plant Sciences, Molecular and Cellular Biology, Medical Microbiology and Immunology, University of California, Davis, CA, 95616, USA.
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Judelson HS, Ah-Fong AMV. Exchanges at the Plant-Oomycete Interface That Influence Disease. PLANT PHYSIOLOGY 2019; 179:1198-1211. [PMID: 30538168 PMCID: PMC6446794 DOI: 10.1104/pp.18.00979] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 11/19/2018] [Indexed: 05/20/2023]
Abstract
Molecular exchanges between plants and biotrophic, hemibiotrophic, and necrotrophic oomycetes affect disease progression.
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Affiliation(s)
- Howard S Judelson
- Department of Microbiology and Plant Pathology, University of California, Riverside, California 92521
| | - Audrey M V Ah-Fong
- Department of Microbiology and Plant Pathology, University of California, Riverside, California 92521
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11
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Hee WY, Blackman LM, Hardham AR. Characterisation of Stramenopile-specific mastigoneme proteins in Phytophthora parasitica. PROTOPLASMA 2019; 256:521-535. [PMID: 30302550 DOI: 10.1007/s00709-018-1314-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 09/25/2018] [Indexed: 06/08/2023]
Abstract
Mastigonemes, tripartite tubular hairs on the anterior flagellum of Phytophthora zoospores, are instrumental for disease dissemination to new host plants. A previous study showed that PnMas2 was part of the tubular shaft of Phytophthora parasitica mastigonemes. In the current study, genes encoding two related proteins, PnMas1 and PnMas3, were identified in the genome of P. parasitica. PnMas1 interacts with PnMas2 and also occurs along the mastigoneme shaft. RNA-Seq analyses indicate that PnMas1 and PnMas2 genes have similar expression profiles both in vitro and in planta but that PnMas3 is expressed temporally prior to PnMas1 and PnMas2 during asexual development and plant infection. Immunocytochemistry and GFP-tagging document the occurrence of all three PnMas proteins within the specialised compartments of the ER during mastigoneme formation, but only PnMas1 and PnMas2 occur in mature mastigonemes on the flagellar surface. Anti-PnMas1 and anti-PnMas2 antibodies co-labelled two high-molecular-weight (~400 kDa) protein complexes in native gels but anti-PnMas3 antibodies labelled a 65 kDa protein complex. Liquid chromatography-mass spectrometry analysis identified PnMas1 and PnMas2 but not PnMas3 in flagellar extracts. These results suggest that PnMas3 associates with mastigonemes during their assembly within the ER but is not part of mature mastigonemes on the anterior flagellum. Phylogenetic analyses using homologues of Mas genes from the genomes of 28 species of Stramenopiles give evidence of three Mas sub-families, namely Mas1, Mas2 and Mas3. BLAST analyses showed that Mas genes only occur in flagellate species within the Stramenopile taxon.
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Affiliation(s)
- Wei Yih Hee
- Plant Science Division, Research School of Biology, College of Science, The Australian National University, Canberra, ACT 2601, Australia.
| | - Leila M Blackman
- Plant Science Division, Research School of Biology, College of Science, The Australian National University, Canberra, ACT 2601, Australia
| | - Adrienne R Hardham
- Plant Science Division, Research School of Biology, College of Science, The Australian National University, Canberra, ACT 2601, Australia
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Kagda MS, Vu AL, Ah-Fong AMV, Judelson HS. Phosphagen kinase function in flagellated spores of the oomycete Phytophthora infestans integrates transcriptional regulation, metabolic dynamics and protein retargeting. Mol Microbiol 2018; 110:296-308. [PMID: 30137656 DOI: 10.1111/mmi.14108] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/20/2018] [Indexed: 11/30/2022]
Abstract
Flagellated spores play important roles in the infection of plants and animals by many eukaryotic microbes. The oomycete Phytophthora infestans, which causes potato blight, expresses two phosphagen kinases (PKs). These enzymes store energy in taurocyamine, and are hypothesized to resolve spatial and temporal imbalances between rates of ATP creation and use in zoospores. A dimeric PK is found at low levels in vegetative mycelia, but high levels in ungerminated sporangia and zoospores. In contrast, a monomeric PK protein is at similar levels in all tissues, although is transcribed primarily in mycelia. Subcellular localization studies indicate that the monomeric PK is mitochondrial. In contrast, the dimeric PK is cytoplasmic in mycelia and sporangia but is retargeted to flagellar axonemes during zoosporogenesis. This supports a model in which PKs shuttle energy from mitochondria to and through flagella. Metabolite analysis indicates that deployment of the flagellar PK is coordinated with a large increase in taurocyamine, synthesized by sporulation-induced enzymes that were lost during the evolution of zoospore-lacking oomycetes. Thus, PK function is enabled by coordination of the transcriptional, metabolic and protein targeting machinery during the life cycle. Since plants lack PKs, the enzymes may be useful targets for inhibitors of oomycete plant pathogens.
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Affiliation(s)
- Meenakshi S Kagda
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, 92521, USA
| | - Andrea L Vu
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, 92521, USA
| | - Audrey M V Ah-Fong
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, 92521, USA
| | - Howard S Judelson
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, 92521, USA
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13
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Nabais C, Pereira SG, Bettencourt-Dias M. Noncanonical Biogenesis of Centrioles and Basal Bodies. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2018; 82:123-135. [PMID: 29686032 DOI: 10.1101/sqb.2017.82.034694] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Centrioles and basal bodies (CBBs) organize centrosomes and cilia within eukaryotic cells. These organelles are composed of microtubules and hundreds of proteins performing multiple functions such as signaling, cytoskeleton remodeling, and cell motility. The CBB is present in all branches of the eukaryotic tree of life and, despite its ultrastructural and protein conservation, there is diversity in its function, occurrence (i.e., presence/absence), and modes of biogenesis across species. In this review, we provide an overview of the multiple pathways through which CBBs are formed in nature, with a special focus on the less studied, noncanonical ways. Despite the differences among each mechanism herein presented, we highlighted some of their common principles. These principles, governing different steps of biogenesis, ensure that CBBs may perform a multitude of functions in a huge diversity of organisms but yet retained their robustness in structure throughout evolution.
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Affiliation(s)
- Catarina Nabais
- Cell Cycle Regulation Lab, Instituto Gulbenkian de Ciência (IGC), 2780-156 Oeiras, Portugal
| | - Sónia Gomes Pereira
- Cell Cycle Regulation Lab, Instituto Gulbenkian de Ciência (IGC), 2780-156 Oeiras, Portugal
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Bourret TB, Choudhury RA, Mehl HK, Blomquist CL, McRoberts N, Rizzo DM. Multiple origins of downy mildews and mito-nuclear discordance within the paraphyletic genus Phytophthora. PLoS One 2018. [PMID: 29529094 PMCID: PMC5846723 DOI: 10.1371/journal.pone.0192502] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Phylogenetic relationships between thirteen species of downy mildew and 103 species of Phytophthora (plant-pathogenic oomycetes) were investigated with two nuclear and four mitochondrial loci, using several likelihood-based approaches. Three Phytophthora taxa and all downy mildew taxa were excluded from the previously recognized subgeneric clades of Phytophthora, though all were strongly supported within the paraphyletic genus. Downy mildews appear to be polyphyletic, with graminicolous downy mildews (GDM), brassicolous downy mildews (BDM) and downy mildews with colored conidia (DMCC) forming a clade with the previously unplaced Phytophthora taxon totara; downy mildews with pyriform haustoria (DMPH) were placed in their own clade with affinities to the obligate biotrophic P. cyperi. Results suggest the recognition of four additional clades within Phytophthora, but few relationships between clades could be resolved. Trees containing all twenty extant downy mildew genera were produced by adding partial coverage of seventeen additional downy mildew taxa; these trees supported the monophyly of the BDMs, DMCCs and DMPHs but suggested that the GDMs are paraphyletic in respect to the BDMs or polyphyletic. Incongruence between nuclear-only and mitochondrial-only trees suggests introgression may have occurred between several clades, particularly those containing biotrophs, questioning whether obligate biotrophic parasitism and other traits with polyphyletic distributions arose independently or were horizontally transferred. Phylogenetic approaches may be limited in their ability to resolve some of the complex relationships between the "subgeneric" clades of Phytophthora, which include twenty downy mildew genera and hundreds of species.
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Affiliation(s)
- Tyler B. Bourret
- Department of Plant Pathology, University of California, Davis, Davis, California, United States of America
- * E-mail:
| | - Robin A. Choudhury
- Plant Pathology Department, University of Florida, Gainesville, Florida, United States of America
| | - Heather K. Mehl
- Department of Plant Pathology, University of California, Davis, Davis, California, United States of America
| | - Cheryl L. Blomquist
- California Department of Food and Agriculture, Sacramento, California, United States of America
| | - Neil McRoberts
- Department of Plant Pathology, University of California, Davis, Davis, California, United States of America
| | - David M. Rizzo
- Department of Plant Pathology, University of California, Davis, Davis, California, United States of America
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Ah-Fong AMV, Shrivastava J, Judelson HS. Lifestyle, gene gain and loss, and transcriptional remodeling cause divergence in the transcriptomes of Phytophthora infestans and Pythium ultimum during potato tuber colonization. BMC Genomics 2017; 18:764. [PMID: 29017458 PMCID: PMC5635513 DOI: 10.1186/s12864-017-4151-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 10/02/2017] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND How pathogen genomes evolve to support distinct lifestyles is not well-understood. The oomycete Phytophthora infestans, the potato blight agent, is a largely biotrophic pathogen that feeds from living host cells, which become necrotic only late in infection. The related oomycete Pythium ultimum grows saprophytically in soil and as a necrotroph in plants, causing massive tissue destruction. To learn what distinguishes their lifestyles, we compared their gene contents and expression patterns in media and a shared host, potato tuber. RESULTS Genes related to pathogenesis varied in temporal expression pattern, mRNA level, and family size between the species. A family's aggregate expression during infection was not proportional to size due to transcriptional remodeling and pseudogenization. Ph. infestans had more stage-specific genes, while Py. ultimum tended towards more constitutive expression. Ph. infestans expressed more genes encoding secreted cell wall-degrading enzymes, but other categories such as secreted proteases and ABC transporters had higher transcript levels in Py. ultimum. Species-specific genes were identified including new Pythium genes, perforins, which may disrupt plant membranes. Genome-wide ortholog analyses identified substantial diversified expression, which correlated with sequence divergence. Pseudogenization was associated with gene family expansion, especially in gene clusters. CONCLUSION This first large-scale analysis of transcriptional divergence within oomycetes revealed major shifts in genome composition and expression, including subfunctionalization within gene families. Biotrophy and necrotrophy seem determined by species-specific genes and the varied expression of shared pathogenicity factors, which may be useful targets for crop protection.
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Affiliation(s)
- Audrey M. V. Ah-Fong
- Department of Plant Pathology and Microbiology, University of California, Riverside, CA 92521 USA
| | - Jolly Shrivastava
- Department of Plant Pathology and Microbiology, University of California, Riverside, CA 92521 USA
| | - Howard S. Judelson
- Department of Plant Pathology and Microbiology, University of California, Riverside, CA 92521 USA
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16
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Abstract
The eukaryotic microbes called oomycetes include many important saprophytes and pathogens, with the latter exhibiting necrotrophy, biotrophy, or obligate biotrophy. Understanding oomycete metabolism is fundamental to understanding these lifestyles. Genome mining and biochemical studies have shown that oomycetes, which belong to the kingdom Stramenopila, secrete suites of carbohydrate- and protein-degrading enzymes adapted to their environmental niches and produce unusual lipids and energy storage compounds. Despite having limited secondary metabolism, many oomycetes make chemicals for communicating within their species or with their hosts. Horizontal and endosymbiotic gene transfer events have diversified oomycete metabolism, resulting in biochemical pathways that often depart from standard textbook descriptions by amalgamating enzymes from multiple sources. Gene fusions and duplications have further shaped the composition and expression of the enzymes. Current research is helping us learn how oomycetes interact with host and environment, understand eukaryotic diversity and evolution, and identify targets for drugs and crop protection chemicals.
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Affiliation(s)
- Howard S Judelson
- Department of Plant Pathology and Microbiology, University of California, Riverside, California 92521;
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17
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Abrahamian M, Ah-Fong AMV, Davis C, Andreeva K, Judelson HS. Gene Expression and Silencing Studies in Phytophthora infestans Reveal Infection-Specific Nutrient Transporters and a Role for the Nitrate Reductase Pathway in Plant Pathogenesis. PLoS Pathog 2016; 12:e1006097. [PMID: 27936244 PMCID: PMC5176271 DOI: 10.1371/journal.ppat.1006097] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 12/21/2016] [Accepted: 11/28/2016] [Indexed: 11/19/2022] Open
Abstract
To help learn how phytopathogens feed from their hosts, genes for nutrient transporters from the hemibiotrophic potato and tomato pest Phytophthora infestans were annotated. This identified 453 genes from 19 families. Comparisons with a necrotrophic oomycete, Pythium ultimum var. ultimum, and a hemibiotrophic fungus, Magnaporthe oryzae, revealed diversity in the size of some families although a similar fraction of genes encoded transporters. RNA-seq of infected potato tubers, tomato leaves, and several artificial media revealed that 56 and 207 transporters from P. infestans were significantly up- or down-regulated, respectively, during early infection timepoints of leaves or tubers versus media. About 17 were up-regulated >4-fold in both leaves and tubers compared to media and expressed primarily in the biotrophic stage. The transcription pattern of many genes was host-organ specific. For example, the mRNA level of a nitrate transporter (NRT) was about 100-fold higher during mid-infection in leaves, which are nitrate-rich, than in tubers and three types of artificial media, which are nitrate-poor. The NRT gene is physically linked with genes encoding nitrate reductase (NR) and nitrite reductase (NiR), which mobilize nitrate into ammonium and amino acids. All three genes were coregulated. For example, the three genes were expressed primarily at mid-stage infection timepoints in both potato and tomato leaves, but showed little expression in potato tubers. Transformants down-regulated for all three genes were generated by DNA-directed RNAi, with silencing spreading from the NR target to the flanking NRT and NiR genes. The silenced strains were nonpathogenic on leaves but colonized tubers. We propose that the nitrate assimilation genes play roles both in obtaining nitrogen for amino acid biosynthesis and protecting P. infestans from natural or fertilization-induced nitrate and nitrite toxicity. Little is known of how plant pathogens adapt to different growth conditions and host tissues. To understand the interaction between the filamentous eukaryotic microbe Phytophthora infestans and its potato and tomato hosts, we mined the genome for genes encoding proteins involved in nutrient uptake and measured their expression in leaves, tubers, and three artificial media. We observed dynamic changes between the growth conditions, and identified transporters expressed mainly in the biotrophic stage, leaves, tubers, or artificial media. When we blocked the expression of a nitrate transporter and two other genes involved in assimilating nitrate, we observed that those genes were required for successful colonization of nitrate-rich leaves but not nitrate-poor tissues, and that nitrate had become toxic to the silenced strains. We therefore hypothesize that the nitrate assimilation pathway may help the pathogen use inorganic nitrogen for nutrition and/or detoxify nitrate when its levels may become damaging.
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Affiliation(s)
- Melania Abrahamian
- Department of Plant Pathology and Microbiology, University of California, Riverside, California, United States of America
| | - Audrey M. V. Ah-Fong
- Department of Plant Pathology and Microbiology, University of California, Riverside, California, United States of America
| | - Carol Davis
- Department of Plant Pathology and Microbiology, University of California, Riverside, California, United States of America
| | - Kalina Andreeva
- Department of Plant Pathology and Microbiology, University of California, Riverside, California, United States of America
| | - Howard S. Judelson
- Department of Plant Pathology and Microbiology, University of California, Riverside, California, United States of America
- * E-mail:
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18
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Fu G, Nagasato C, Oka S, Cock JM, Motomura T. Proteomics analysis of heterogeneous flagella in brown algae (stramenopiles). Protist 2014; 165:662-75. [PMID: 25150613 DOI: 10.1016/j.protis.2014.07.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 07/22/2014] [Accepted: 07/22/2014] [Indexed: 10/25/2022]
Abstract
Flagella are conserved organelles among eukaryotes and they are composed of many proteins, which are necessary for flagellar assembly, maintenance and function. Stramenopiles, which include brown algae, diatoms and oomycetes, possess two laterally inserted flagella. The anterior flagellum (AF) extends forward and bears tripartite mastigonemes, whilst the smooth posterior flagellum (PF) often has a paraflagellar body structure. These heterogeneous flagella have served as crucial structures in algal studies especially from a viewpoint of phylogeny. However, the protein compositions of the flagella are still largely unknown. Here we report a LC-MS/MS based proteomics analysis of brown algal flagella. In total, 495 flagellar proteins were identified. Functional annotation of the proteome data revealed that brown algal flagellar proteins were associated with cell motility, signal transduction and various metabolic activities. We separately isolated AF and PF and analyzed their protein compositions. This analysis led to the identification of several AF- and PF-specific proteins. Among the PF-specific proteins, we found a candidate novel blue light receptor protein involved in phototaxis, and named it HELMCHROME because of the steering function of PF. Immunological analysis revealed that this protein was localized along the whole length of the PF and concentrated in the paraflagellar body.
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Affiliation(s)
- Gang Fu
- Muroran Marine Station, Field Science Center for Northern Biosphere, Hokkaido University, Muroran 051-0013, Hokkaido, Japan
| | - Chikako Nagasato
- Muroran Marine Station, Field Science Center for Northern Biosphere, Hokkaido University, Muroran 051-0013, Hokkaido, Japan
| | - Seiko Oka
- Instrumental Analysis Division, Equipment Management Center, Creative Research Institution, Hokkaido University, Sapporo 001-0021, Hokkaido, Japan
| | - J Mark Cock
- University Pierre et Marie Curie and Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7139, Laboratoire International Associé Dispersal and Adaptation in Marine Species, Station Biologique de Roscoff, 29682 Roscoff Cedex, France
| | - Taizo Motomura
- Muroran Marine Station, Field Science Center for Northern Biosphere, Hokkaido University, Muroran 051-0013, Hokkaido, Japan.
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Steciow MM, Lara E, Pillonel A, Pelizza SA, Lestani EA, Rossi GC, Belbahri L. Incipient loss of flagella in the genus Geolegnia: the emergence of a new clade within Leptolegnia? IMA Fungus 2013; 4:169-75. [PMID: 24563829 PMCID: PMC3905935 DOI: 10.5598/imafungus.2013.04.02.02] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 09/28/2013] [Indexed: 11/13/2022] Open
Abstract
The genus Geolegnia represents a poorly documented group of saprolegnialean oomycetes isolated from soils as free-living organisms. Although it is morphologically similar to the facultative parasitic genus Leptolegnia, Geolegnia presents the uncommon property of having lost a flagellate stage in its lifecycle. Based on ITS and large subunit (LSU) rRNA sequence data, we show Geolegnia to be basal to Leptolegnia, and also introduce Geolegnia helicoides sp. nov. Using sequence data of Leptolegnia available in GenBank, supplemented by data derived from culture collections, we show that Geolegnia is nested within Leptolegnia, a genus characterised by its “conventional” biflagellate life cycle. The emergence of Geolegnia is therefore seen as a recent event, and we suggest here an evolutionary context where this loss might have been advantageous. Based on this study, Leptolegnia remains paraphyletic, awaiting the redefinition of genera in this complex.
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Affiliation(s)
- Mónica M Steciow
- Instituto de Botánica Spegazzini, 53 N° 477, (1900) La Plata, Buenos Aires, Argentina
| | - Enrique Lara
- Laboratory of Soil Biology, Department of Biology, University of Neuchâtel, 11 Rue Emile Argand, CH-2000, Neuchâtel, Switzerland
| | - Amandine Pillonel
- Laboratory of Soil Biology, Department of Biology, University of Neuchâtel, 11 Rue Emile Argand, CH-2000, Neuchâtel, Switzerland
| | - Sebastián A Pelizza
- Instituto de Botánica Spegazzini, 53 N° 477, (1900) La Plata, Buenos Aires, Argentina; ; CEPAVE-CCT -CONICET, La Plata, Argentina
| | - Eduardo A Lestani
- Centro de Investigaciones Ecológicas Subtropicales, Parque Nacional Iguazú /Asoc. Civil Centro de Investigaciones del Bosque Atlántico, Pto. Iguazú, Misiones, Argentina
| | | | - Lassaad Belbahri
- Laboratory of Soil Biology, Department of Biology, University of Neuchâtel, 11 Rue Emile Argand, CH-2000, Neuchâtel, Switzerland
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Roy S, Poidevin L, Jiang T, Judelson HS. Novel core promoter elements in the oomycete pathogen Phytophthora infestans and their influence on expression detected by genome-wide analysis. BMC Genomics 2013; 14:106. [PMID: 23414203 PMCID: PMC3599244 DOI: 10.1186/1471-2164-14-106] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Accepted: 01/31/2013] [Indexed: 12/19/2022] Open
Abstract
Background The core promoter is the region flanking the transcription start site (TSS) that directs formation of the pre-initiation complex. Core promoters have been studied intensively in mammals and yeast, but not in more diverse eukaryotes. Here we investigate core promoters in oomycetes, a group within the Stramenopile kingdom that includes important plant and animal pathogens. Prior studies of a small collection of genes proposed that oomycete core promoters contain a 16 to 19 nt motif bearing an Initiator-like sequence (INR) flanked by a novel sequence named FPR, but this has not been extended to whole-genome analysis. Results We used expectation maximization to find over-represented motifs near TSSs of Phytophthora infestans, the potato blight pathogen. The motifs corresponded to INR, FPR, and a new element found about 25 nt downstream of the TSS called DPEP. TATA boxes were not detected. Assays of DPEP function by mutagenesis were consistent with its role as a core motif. Genome-wide searches found a well-conserved combined INR+FPR in only about 13% of genes after correcting for false discovery, which contradicted prior reports that INR and FPR are found together in most genes. INR or FPR were found alone near TSSs in 18% and 7% of genes, respectively. Promoters lacking the motifs had pyrimidine-rich regions near the TSS. The combined INR+FPR motif was linked to higher than average mRNA levels, developmentally-regulated transcription, and functions related to plant infection, while DPEP and FPR were over-represented in constitutively-expressed genes. The INR, FPR, and combined INR+FPR motifs were detected in other oomycetes including Hyaloperonospora arabidopsidis, Phytophthora sojae, Pythium ultimum, and Saprolegnia parasitica, while DPEP was found in all but S. parasitica. Only INR seemed present in a non-oomycete stramenopile. Conclusions The absence of a TATA box and presence of novel motifs show that the oomycete core promoter is diverged from that of model systems, and likely explains the lack of activity of non-oomycete promoters in Phytophthora transformants. The association of the INR+FPR motif with developmentally-regulated genes shows that oomycete core elements influence stage-specific transcription in addition to regulating formation of the pre-initiation complex.
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Affiliation(s)
- Sourav Roy
- Department of Plant Pathology and Microbiology, University of California, 92521, Riverside, CA 92521, USA
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