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Higashimura N, Hamada A, Ohara T, Sakurai S, Ito H, Banba S. The target site of the novel fungicide quinofumelin, Pyricularia oryzae class II dihydroorotate dehydrogenase. J Pestic Sci 2022; 47:190-196. [PMID: 36514691 PMCID: PMC9716045 DOI: 10.1584/jpestics.d22-027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 08/24/2022] [Indexed: 06/17/2023]
Abstract
The target site of the novel fungicide quinofumelin was investigated in the rice blast fungus Pyricularia oryzae. Quinofumelin-induced mycelial growth inhibition was reversed by orotate but not by dihydroorotate. Recovery tests suggested that the target site of quinofumelin was dihydroorotate dehydrogenase (DHODH), which catalyzes the oxidation of dihydroorotate to orotate. Quinofumelin strongly inhibited P. oryzae class 2 DHODH (DHODH II) (IC50: 2.8 nM). The inhibitory activities of mycelial growth and DHODH II were strongly positively correlated, indicating that DHODH II inhibition by quinofumelin lead to antifungal activity. A P. oryzae DHODH II gene (PoPYR4) disruption mutant (ΔPopyr4), showing the same tendency as the quinofumelin-treated wild strain in recovery tests, was constructed, and disease symptoms were not observed in rice plants infected by ΔPopyr4. Thus, DHODH II, which plays an important role in pathogenicity and mycelial growth, is found to be the target site of quinofumelin.
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Affiliation(s)
| | - Akira Hamada
- Agrochemicals Research Center, Mitsui Chemicals Agro, Inc
| | - Toshiaki Ohara
- Agrochemicals Research Center, Mitsui Chemicals Agro, Inc
| | | | - Hiroyuki Ito
- Agrochemicals Research Center, Mitsui Chemicals Agro, Inc
| | - Shinichi Banba
- Agrochemicals Research Center, Mitsui Chemicals Agro, Inc
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Mutiga SK, Rotich F, Were VM, Kimani JM, Mwongera DT, Mgonja E, Onaga G, Konaté K, Razanaboahirana C, Bigirimana J, Ndayiragije A, Gichuhi E, Yanoria MJ, Otipa M, Wasilwa L, Ouedraogo I, Mitchell T, Wang GL, Correll JC, Talbot NJ. Integrated Strategies for Durable Rice Blast Resistance in Sub-Saharan Africa. Plant Dis 2021; 105:2749-2770. [PMID: 34253045 DOI: 10.1094/pdis-03-21-0593-fe] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Rice is a key food security crop in Africa. The importance of rice has led to increasing country-specific, regional, and multinational efforts to develop germplasm and policy initiatives to boost production for a more food-secure continent. Currently, this critically important cereal crop is predominantly cultivated by small-scale farmers under suboptimal conditions in most parts of sub-Saharan Africa (SSA). Rice blast disease, caused by the fungus Magnaporthe oryzae, represents one of the major biotic constraints to rice production under small-scale farming systems of Africa, and developing durable disease resistance is therefore of critical importance. In this review, we provide an overview of the major advances by a multinational collaborative research effort to enhance sustainable rice production across SSA and how it is affected by advances in regional policy. As part of the multinational effort, we highlight the importance of joint international partnerships in tackling multiple crop production constraints through integrated research and outreach programs. More specifically, we highlight recent progress in establishing international networks for rice blast disease surveillance, farmer engagement, monitoring pathogen virulence spectra, and the establishment of regionally based blast resistance breeding programs. To develop blast-resistant, high yielding rice varieties for Africa, we have established a breeding pipeline that utilizes real-time data of pathogen diversity and virulence spectra, to identify major and minor blast resistance genes for introgression into locally adapted rice cultivars. In addition, the project has developed a package to support sustainable rice production through regular stakeholder engagement, training of agricultural extension officers, and establishment of plant clinics.
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Affiliation(s)
- Samuel K Mutiga
- Biosciences eastern and central Africa - International Livestock Research Institute (BecA-ILRI), Nairobi, Kenya
- Department of Entomology and Plant Pathology, University of Arkansas, Fayetteville, AR 72701, U.S.A
| | - Felix Rotich
- Department of Agricultural Resource Management, University of Embu, Embu, Kenya
| | - Vincent M Were
- The Sainsbury Laboratory, University of East Anglia, Norwich NR4 7UH, U.K
| | - John M Kimani
- Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya
| | - David T Mwongera
- Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya
| | | | - Geoffrey Onaga
- National Agricultural Research Organization, Kampala, Uganda
| | - Kadougoudiou Konaté
- Institute of Environment and Agricultural Research, Bobo-Dioulasso, Burkina Faso
| | | | | | | | - Emily Gichuhi
- Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya
| | | | - Miriam Otipa
- Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya
| | - Lusike Wasilwa
- Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya
| | - Ibrahima Ouedraogo
- Institute of Environment and Agricultural Research, Bobo-Dioulasso, Burkina Faso
| | - Thomas Mitchell
- Department of Plant Pathology, The Ohio State University, Columbus, OH 43210, U.S.A
| | - Guo-Liang Wang
- Department of Plant Pathology, The Ohio State University, Columbus, OH 43210, U.S.A
| | - James C Correll
- Department of Entomology and Plant Pathology, University of Arkansas, Fayetteville, AR 72701, U.S.A
| | - Nicholas J Talbot
- The Sainsbury Laboratory, University of East Anglia, Norwich NR4 7UH, U.K
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Thaker A, Mehta K, Patkar R. Feruloyl esterase Fae1 is required specifically for host colonisation by the rice-blast fungus Magnaporthe oryzae. Curr Genet 2021. [PMID: 34524467 DOI: 10.1007/s00294-021-01213-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 08/29/2021] [Accepted: 09/03/2021] [Indexed: 10/20/2022]
Abstract
Plant cell wall acts as a primary barrier for microbial pathogens during infection. A cell wall-degrading enzyme thus may be a crucial virulence factor, as it may aid the pathogen in successful host invasion. Nine genes coding for feruloyl esterases (Fae), likely involved in plant cell wall degradation, have been annotated in the genome of the cereal-blast fungus Magnaporthe oryzae. However, role of any Fae in pathogenicity of M. oryzae remains hitherto under explored. Here, we identified FAE1 gene (MGG_08737) that was significantly upregulated during host penetration and subsequent colonisation stages of infection. Accordingly, while deletion of FAE1 in M. oryzae did not affect the vegetative growth and asexual development, the fae1Δ mutant showed significantly reduced pathogenesis on rice plants, mainly due to impaired host invasion and colonisation. Very few (< 10%) fae1Δ appressoria that formed the primary invasive hyphae failed to elaborate from the first invaded cell to the neighbouring plant cells. Interestingly, exogenously added glucose, as a simple carbon source, or ferulic acid, a product of the Fae activity, significantly supported the invasive growth of the fae1Δ mutant. We show that the Fae1-based feruloyl esterase activity, by targeting the plant cell wall, plays an important role in accumulating ferulic acid and/or sugar molecules, as a likely energy source, to enable host invasion and colonisation by M. oryzae. Given its role in plant cell wall digestion and host colonisation, M. oryzae Fae1 could be a potential candidate for a novel antifungal strategy and a biotechnological application in biofuel production.
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Cruz-Mireles N, Eisermann I, Garduño-Rosales M, Molinari C, Ryder LS, Tang B, Yan X, Talbot NJ. The Biology of Invasive Growth by the Rice Blast Fungus Magnaporthe oryzae. Methods Mol Biol 2021; 2356:19-40. [PMID: 34236674 DOI: 10.1007/978-1-0716-1613-0_2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This introductory chapter describes the life cycle of Magnaporthe oryzae, the causal agent of rice blast disease. During plant infection, M. oryzae forms a specialized infection structure called an appressorium, which generates enormous turgor, applied as a mechanical force to breach the rice cuticle. Appressoria form in response to physical cues from the hydrophobic rice leaf cuticle and nutrient availability. The signaling pathways involved in perception of surface signals are described and the mechanism by which appressoria function is also introduced. Re-polarization of the appressorium requires a septin complex to organize a toroidal F-actin network at the base of the cell. Septin aggregation requires a turgor-dependent sensor kinase, Sln1, necessary for re-polarization of the appressorium and development of a rigid penetration hypha to rupture the leaf cuticle. Once inside the plant, the fungus undergoes secretion of a large set of effector proteins, many of which are directed into plant cells using a specific secretory pathway. Here they suppress plant immunity, but can also be perceived by rice immune receptors, triggering resistances. M. oryzae then manipulates pit field sites, containing plasmodesmata, to facilitate rapid spread from cell to cell in plant tissue, leading to disease symptom development.
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Franco Ortega S, Ferrocino I, Adams I, Silvestri S, Spadaro D, Gullino ML, Boonham N. Monitoring and Surveillance of Aerial Mycobiota of Rice Paddy through DNA Metabarcoding and qPCR. J Fungi (Basel) 2020; 6:jof6040372. [PMID: 33348656 PMCID: PMC7766667 DOI: 10.3390/jof6040372] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 12/10/2020] [Accepted: 12/14/2020] [Indexed: 01/16/2023] Open
Abstract
The airborne mycobiota has been understudied in comparison with the mycobiota present in other agricultural environments. Traditional, culture-based methods allow the study of a small fraction of the organisms present in the atmosphere, thus missing important information. In this study, the aerial mycobiota in a rice paddy has been examined during the cropping season (from June to September 2016) using qPCRs for two important rice pathogens (Pyricularia oryzae and Bipolaris oryzae) and by using DNA metabarcoding of the fungal ITS region. The metabarcoding results demonstrated a higher alpha diversity (Shannon–Wiener diversity index H′ and total number of observed species) at the beginning of the trial (June), suggesting a higher level of community complexity, compared with the end of the season. The main taxa identified by HTS analysis showed a shift in their relative abundance that drove the cluster separation as a function of time and temperature. The most abundant OTUs corresponded to genera such as Cladosporium, Alternaria, Myrothecium, or Pyricularia. Changes in the mycobiota composition were clearly dependent on the average air temperature with a potential impact on disease development in rice. In parallel, oligotyping analysis was performed to obtain a sub-OTU identification which revealed the presence of several oligotypes of Pyricularia and Bipolaris with relative abundance changing during monitoring.
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Affiliation(s)
- Sara Franco Ortega
- Centre of Competence for the Innovation in the Agro-Environmental Sector—AGROINNOVA, University of Turin, Via Paolo Braccini 2, I-10095 Grugliasco (TO), Italy; (S.F.O.); (M.L.G.)
| | - Ilario Ferrocino
- Department of Agricultural, Forestry and Food Sciences (DiSAFA), University of Torino, Via Paolo Braccini 2, I-10095 Grugliasco (TO), Italy;
| | - Ian Adams
- FERA, National Agri-Food Innovation Campus, Sand Hutton, York YO41 1LZ, UK;
| | - Simone Silvestri
- Ente Nazionale per la Risicultura (ENTERISI), Strada per Ceretto 4, 27030 Castello d’Agogna (PV), Italy;
| | - Davide Spadaro
- Centre of Competence for the Innovation in the Agro-Environmental Sector—AGROINNOVA, University of Turin, Via Paolo Braccini 2, I-10095 Grugliasco (TO), Italy; (S.F.O.); (M.L.G.)
- Department of Agricultural, Forestry and Food Sciences (DiSAFA), University of Torino, Via Paolo Braccini 2, I-10095 Grugliasco (TO), Italy;
- Correspondence:
| | - Maria Lodovica Gullino
- Centre of Competence for the Innovation in the Agro-Environmental Sector—AGROINNOVA, University of Turin, Via Paolo Braccini 2, I-10095 Grugliasco (TO), Italy; (S.F.O.); (M.L.G.)
- Department of Agricultural, Forestry and Food Sciences (DiSAFA), University of Torino, Via Paolo Braccini 2, I-10095 Grugliasco (TO), Italy;
| | - Neil Boonham
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK;
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Zheng H, Zhong Z, Shi M, Zhang L, Lin L, Hong Y, Fang T, Zhu Y, Guo J, Zhang L, Fang J, Lin H, Norvienyeku J, Chen X, Lu G, Hu H, Wang Z. Comparative genomic analysis revealed rapid differentiation in the pathogenicity-related gene repertoires between Pyricularia oryzae and Pyricularia penniseti isolated from a Pennisetum grass. BMC Genomics 2018; 19:927. [PMID: 30545292 PMCID: PMC6293661 DOI: 10.1186/s12864-018-5222-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Accepted: 11/05/2018] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND A number of Pyricularia species are known to infect different grass species. In the case of Pyricularia oryzae (syn. Magnaporthe oryzae), distinct populations are known to be adapted to a wide variety of grass hosts, including rice, wheat and many other grasses. The genome sizes of Pyricularia species are typical for filamentous ascomycete fungi [~ 40 Mbp for P. oryzae, and ~ 45 Mbp for P. grisea]. Genome plasticity, mediated in part by deletions promoted by recombination between repetitive elements [Genome Res 26:1091-1100, 2016, Nat Rev Microbiol 10:417-430,2012] and transposable elements [Annu Rev Phytopathol 55:483-503,2017] contributes to host adaptation. Therefore, comparisons of genome structure of individual species will provide insight into the evolution of host specificity. However, except for the P. oryzae subgroup, little is known about the gene content or genome organization of other Pyricularia species, such as those infecting Pennisetum grasses. RESULTS Here, we report the genome sequence of P. penniseti strain P1609 isolated from a Pennisetum grass (JUJUNCAO) using PacBio SMRT sequencing technology. Phylogenomic analysis of 28 Magnaporthales species and 5 non-Magnaporthales species indicated that P1609 belongs to a Pyricularia subclade, which is genetically distant from P. oryzae. Comparative genomic analysis revealed that the pathogenicity-related gene repertoires had diverged between P1609 and the P. oryzae strain 70-15, including the known avirulence genes, other putative secreted proteins, as well as some other predicted Pathogen-Host Interaction (PHI) genes. Genomic sequence comparison also identified many genomic rearrangements relative to P. oryzae. CONCLUSION Our results suggested that the genomic sequence of the P. penniseti P1609 could be a useful resource for the genetic study of the Pennisetum-infecting Pyricularia species and provide new insight into evolution of pathogen genomes during host adaptation.
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Affiliation(s)
- Huakun Zheng
- National Engineering Research Center of JUNCAO Technology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
| | - Zhenhui Zhong
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
| | - Mingyue Shi
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
| | - Limei Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
| | - Lianyu Lin
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
- College of life science, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
| | - Yonghe Hong
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
- College of life science, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
| | - Tian Fang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
| | - Yangyan Zhu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
| | - Jiayuan Guo
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
| | - Limin Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
| | - Jie Fang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
- College of life science, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
| | - Hui Lin
- National Engineering Research Center of JUNCAO Technology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
| | - Justice Norvienyeku
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
- College of life science, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
| | - Xiaofeng Chen
- Institute of Oceanography, Minjiang University, Fuzhou, 350108 China
| | - Guodong Lu
- National Engineering Research Center of JUNCAO Technology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
| | - Hongli Hu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
| | - Zonghua Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
- College of life science, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
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Osés-Ruiz M, Sakulkoo W, Littlejohn GR, Martin-Urdiroz M, Talbot NJ. Two independent S-phase checkpoints regulate appressorium-mediated plant infection by the rice blast fungus Magnaporthe oryzae. Proc Natl Acad Sci U S A 2017; 114:E237-E244. [PMID: 28028232 PMCID: PMC5240714 DOI: 10.1073/pnas.1611307114] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
To cause rice blast disease, the fungal pathogen Magnaporthe oryzae develops a specialized infection structure called an appressorium. This dome-shaped, melanin-pigmented cell generates enormous turgor and applies physical force to rupture the rice leaf cuticle using a rigid penetration peg. Appressorium-mediated infection requires septin-dependent reorientation of the F-actin cytoskeleton at the base of the infection cell, which organizes polarity determinants necessary for plant cell invasion. Here, we show that plant infection by M. oryzae requires two independent S-phase cell-cycle checkpoints. Initial formation of appressoria on the rice leaf surface requires an S-phase checkpoint that acts through the DNA damage response (DDR) pathway, involving the Cds1 kinase. By contrast, appressorium repolarization involves a novel, DDR-independent S-phase checkpoint, triggered by appressorium turgor generation and melanization. This second checkpoint specifically regulates septin-dependent, NADPH oxidase-regulated F-actin dynamics to organize the appressorium pore and facilitate entry of the fungus into host tissue.
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Affiliation(s)
- Míriam Osés-Ruiz
- School of Biosciences, University of Exeter, Exeter EX4 4QD, United Kingdom
| | - Wasin Sakulkoo
- School of Biosciences, University of Exeter, Exeter EX4 4QD, United Kingdom
| | | | | | - Nicholas J Talbot
- School of Biosciences, University of Exeter, Exeter EX4 4QD, United Kingdom
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Zhang N, Luo J, Rossman AY, Aoki T, Chuma I, Crous PW, Dean R, de Vries RP, Donofrio N, Hyde KD, Lebrun MH, Talbot NJ, Tharreau D, Tosa Y, Valent B, Wang Z, Xu JR. Generic names in Magnaporthales. IMA Fungus 2016; 7:155-9. [PMID: 27433445 PMCID: PMC4941683 DOI: 10.5598/imafungus.2016.07.01.09] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 05/15/2016] [Indexed: 11/04/2022] Open
Abstract
The order Magnaporthales comprises about 200 species and includes the economically and scientifically important rice blast fungus and the take-all pathogen of cereals, as well as saprotrophs and endophytes. Recent advances in phylogenetic analyses of these fungi resulted in taxonomic revisions. In this paper we list the 28 currently accepted genera in Magnaporthales with their type species and available gene and genome resources. The polyphyletic Magnaporthe 1972 is proposed for suppression, and Pyricularia 1880 and Nakataea 1939 are recommended for protection as the generic names for the rice blast fungus and the rice stem rot fungus, respectively. The rationale for the recommended names is also provided. These recommendations are made by the Pyricularia/Magnaporthe Working Group established under the auspices of the International Commission on the Taxonomy of Fungi (ICTF).
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Affiliation(s)
- Ning Zhang
- Department of Plant Biology and Pathology, Rutgers University, New Brunswick, NJ 08901, USA
| | - Jing Luo
- Department of Plant Biology and Pathology, Rutgers University, New Brunswick, NJ 08901, USA
| | - Amy Y Rossman
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon 97331, USA
| | - Takayuki Aoki
- Genetic Resources Center, National Agriculture and Food Research Organization, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan
| | - Izumi Chuma
- Kobe University, 1-1 Rokkodai cho, Nada-ku, Kobe 657-8501, Japan
| | - Pedro W Crous
- CBS-KNAW Fungal Biodiversity Institute, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Ralph Dean
- Department of Plant Pathology, 2510 Thomas Hall, Raleigh, NC 27695, North Carolina State University, USA
| | - Ronald P de Vries
- CBS-KNAW Fungal Biodiversity Institute, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands; Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Nicole Donofrio
- Department of Plant and Soil Sciences, University of Delaware, 531 S. College Ave, 152 Townsend Hall, Newark, DE 19711, USA
| | - Kevin D Hyde
- Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, Thailand
| | - Marc-Henri Lebrun
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, 78850 Thiverval-Grignon, France
| | | | | | - Yukio Tosa
- Kobe University, 1-1 Rokkodai cho, Nada-ku, Kobe 657-8501, Japan
| | - Barbara Valent
- Department of Plant Pathology, Kansas State University, Manhattan, KS 66506-5502, USA
| | - Zonghua Wang
- Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
| | - Jin-Rong Xu
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA
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Abstract
Species of Pyricularia (magnaporthe-like sexual morphs) are responsible for major diseases on grasses. Pyricularia oryzae (sexual morph Magnaporthe oryzae) is responsible for the major disease of rice called rice blast disease, and foliar diseases of wheat and millet, while Pyricularia grisea (sexual morph Magnaporthe grisea) is responsible for foliar diseases of Digitaria. Magnaporthe salvinii, M. poae and M. rhizophila produce asexual spores that differ from those of Pyricularia sensu stricto that has pyriform, 2-septate conidia produced on conidiophores with sympodial proliferation. Magnaporthe salvinii was recently allocated to Nakataea, while M. poae and M. rhizophila were placed in Magnaporthiopsis. To clarify the taxonomic relationships among species that are magnaporthe- or pyricularia-like in morphology, we analysed phylogenetic relationships among isolates representing a wide range of host plants by using partial DNA sequences of multiple genes such as LSU, ITS, RPB1, actin and calmodulin. Species of Pyricularia s. str. belong to a monophyletic clade that includes all P. oryzae/P. grisea isolates tested, defining the Pyriculariaceae, which is sister to the Ophioceraceae, representing two novel families. These clades are clearly distinct from species belonging to the Gaeumannomyces pro parte/Magnaporthiopsis/Nakataea generic complex that are monophyletic and define the Magnaporthaceae. A few magnaporthe- and pyricularia-like species are unrelated to Magnaporthaceae and Pyriculariaceae. Pyricularia oryzae/P. grisea isolates cluster into two related clades. Host plants such as Eleusine, Oryza, Setaria or Triticum were exclusively infected by isolates from P. oryzae, while some host plant such as Cenchrus, Echinochloa, Lolium, Pennisetum or Zingiber were infected by different Pyricularia species. This demonstrates that host range cannot be used as taxonomic criterion without extensive pathotyping. Our results also show that the typical pyriform, 2-septate conidium morphology of P. grisea/P. oryzae is restricted to Pyricularia and Neopyricularia, while most other genera have obclavate to more ellipsoid 2-septate conidia. Some related genera (Deightoniella, Macgarvieomyces) have evolved 1-septate conidia. Therefore, conidium morphology cannot be used as taxonomic criterion at generic level without phylogenetic data. We also identified 10 novel genera, and seven novel species. A re-evaluation of generic and species concepts within Pyriculariaceae is presented, and novelties are proposed based on morphological and phylogenetic data.
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Affiliation(s)
- S. Klaubauf
- CBS-KNAW Fungal Biodiversity Centre, 3584 CT Utrecht, The Netherlands
- Fungal Molecular Physiology, Utrecht University, Utrecht, The Netherlands
| | - D. Tharreau
- UMR BGPI, CIRAD, Campus International de Baillarguet, F-34398 Montpellier, France
| | - E. Fournier
- UMR BGPI, INRA, Campus International de Baillarguet, F-34398 Montpellier, France
| | - J.Z. Groenewald
- CBS-KNAW Fungal Biodiversity Centre, 3584 CT Utrecht, The Netherlands
| | - P.W. Crous
- CBS-KNAW Fungal Biodiversity Centre, 3584 CT Utrecht, The Netherlands
- Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa
- Wageningen University and Research Centre (WUR), Laboratory of Phytopathology, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - R.P. de Vries
- CBS-KNAW Fungal Biodiversity Centre, 3584 CT Utrecht, The Netherlands
- Fungal Molecular Physiology, Utrecht University, Utrecht, The Netherlands
| | - M.-H. Lebrun
- UR1290 INRA BIOGER-CPP, Campus AgroParisTech, F-78850 Thiverval-Grignon, France
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Abstract
Based on morphology and DNA sequences of SSU, ITS, LSU, MCM7, RPB1 and TEF1 genes, we describe four new species in Magnaporthaceae that are associated with grass roots collected from New Jersey Pine Barrens. A new genus, Pseudophialophora, is erected to accommodate three species, which is characterized by slow growth on potato dextrose agar, curved conidiogenous cells without a conspicuous collarette at the apex and oblong ellipsoidal conidia. Pseudophialophora eragrostis, P. panicorum and P. schizachyrii are assigned to this genus. A new species of Magnaporthiopsis also is reported and named as M. panicorum. Distinctions between them and phylogenetic relationships with other Magnaporthaceae taxa are discussed.
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Affiliation(s)
- Jing Luo
- Department of Plant Biology and Pathology, 201 Foran Hall, 59 Dudley Road, Rutgers University, New Brunswick, New Jersey 08901
| | - Emily Walsh
- Department of Plant Biology and Pathology, 201 Foran Hall, 59 Dudley Road, Rutgers University, New Brunswick, New Jersey 08901
| | - Ning Zhang
- Department of Plant Biology and Pathology, 201 Foran Hall, 59 Dudley Road, Rutgers University, New Brunswick, New Jersey 08901
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