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Wijayawardene NN, Hyde KD, Dai DQ, Sánchez-García M, Goto BT, Saxena RK, Erdoğdu M, Selçuk F, Rajeshkumar KC, Aptroot A, Błaszkowski J, Boonyuen N, da Silva GA, de Souza FA, Dong W, Ertz D, Haelewaters D, Jones EBG, Karunarathna SC, Kirk PM, Kukwa M, Kumla J, Leontyev DV, Lumbsch HT, Maharachchikumbura SSN, Marguno F, Martínez-Rodríguez P, Mešić A, Monteiro JS, Oehl F, Pawłowska J, Pem D, Pfliegler WP, Phillips AJL, Pošta A, He MQ, Li JX, Raza M, Sruthi OP, Suetrong S, Suwannarach N, Tedersoo L, Thiyagaraja V, Tibpromma S, Tkalčec Z, Tokarev YS, Wanasinghe DN, Wijesundara DSA, Wimalaseana SDMK, Madrid H, Zhang GQ, Gao Y, Sánchez-Castro I, Tang LZ, Stadler M, Yurkov A, Thines M. Outline of Fungi and fungus-like taxa – 2021. MYCOSPHERE 2022. [DOI: 10.5943/mycosphere/13/1/2] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Ploch S, Kruse J, Choi YJ, Thiel H, Thines M. Ancestral state reconstruction in Peronospora provides further evidence for host jumping as a key element in the diversification of obligate parasites. Mol Phylogenet Evol 2021; 166:107321. [PMID: 34626809 DOI: 10.1016/j.ympev.2021.107321] [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: 02/22/2021] [Revised: 09/08/2021] [Accepted: 10/04/2021] [Indexed: 11/15/2022]
Abstract
Biotrophic plant parasites cause economically important diseases, e.g. downy mildew of grape, powdery mildew of legumes, wheat stripe rust, and wheat bunt. But also in natural ecosystems, these organisms are abundant and diverse, and for many hosts more than one specialised biotrophic pathogen is known. However, only a fraction of their diversity is thought to have been described. There is accumulating evidence for the importance of host jumping for the diversification of obligate biotrophic pathogens but tracing this process along the phylogeny of pathogens is often complicated by a lack of resolution of phylogenetic trees, low taxon and specimen sampling, or either too few or too many host jumps in the pathogen group in question. Here, a clade of Peronospora species mostly infecting members of the Ranunculales was investigated using multigene analyses and ancestral state reconstructions. These analyses show that this clade started out in Papaveraceae, with subsequent host jumps to Berberidaceae, Euphorbiaceae, and Ranunculaceae. In Ranunculaceae, radiation to a variety of hosts took place, and a new host jump occurred to Caryophyllaceae. This highlights that host jumping and subsequent radiation is a key evolutionary process driving the diversification of Peronospora. It seems likely that the observed pattern can be generalised to other obligate parasite lineages, as diverse hosts in unrelated families have also been reported for other pathogen groups, including powdery mildew, rust fungi, and smut fungi.
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Zuo W, Depotter JRL, Gupta DK, Thines M, Doehlemann G. Cross-species analysis between the maize smut fungi Ustilago maydis and Sporisorium reilianum highlights the role of transcriptional change of effector orthologs for virulence and disease. THE NEW PHYTOLOGIST 2021; 232:719-733. [PMID: 34270791 DOI: 10.1111/nph.17625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 07/07/2021] [Indexed: 06/13/2023]
Abstract
The constitution and regulation of effector repertoires shape host-microbe interactions. Ustilago maydis and Sporisorium reilianum are two closely related smut fungi, which both infect maize but cause distinct disease symptoms. Understanding how effector orthologs are regulated in these two pathogens can therefore provide insights into the evolution of different infection strategies. We tracked the infection progress of U. maydis and S. reilianum in maize leaves and used two distinct infection stages for cross-species RNA-sequencing analyses. We identified 207 of 335 one-to-one effector orthologs as differentially regulated during host colonization, which might reflect the distinct disease development strategies. Using CRISPR-Cas9-mediated gene conversion, we identified two differentially expressed effector orthologs with conserved function between two pathogens. Thus, differential expression of functionally conserved genes might contribute to species-specific adaptation and symptom development. Interestingly, another differentially expressed orthogroup (UMAG_05318/Sr10075) showed divergent protein function, providing a possible case for neofunctionalization. Collectively, we demonstrated that the diversification of effector genes in related pathogens can be caused both by alteration on the transcriptional level and through functional diversification of the encoded effector proteins.
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Cao B, Haelewaters D, Schoutteten N, Begerow D, Boekhout T, Giachini AJ, Gorjón SP, Gunde-Cimerman N, Hyde KD, Kemler M, Li GJ, Liu DM, Liu XZ, Nuytinck J, Papp V, Savchenko A, Savchenko K, Tedersoo L, Theelen B, Thines M, Tomšovský M, Toome-Heller M, Urón JP, Verbeken A, Vizzini A, Yurkov AM, Zamora JC, Zhao RL. Delimiting species in Basidiomycota: a review. FUNGAL DIVERS 2021. [DOI: 10.1007/s13225-021-00479-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Ulaszewski B, Meger J, Mishra B, Thines M, Burczyk J. Complete Chloroplast Genomes of Fagus sylvatica L. Reveal Sequence Conservation in the Inverted Repeat and the Presence of Allelic Variation in NUPTs. Genes (Basel) 2021; 12:1357. [PMID: 34573338 PMCID: PMC8468245 DOI: 10.3390/genes12091357] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 08/21/2021] [Accepted: 08/27/2021] [Indexed: 12/17/2022] Open
Abstract
Growing amounts of genomic data and more efficient assembly tools advance organelle genomics at an unprecedented scale. Genomic resources are increasingly used for phylogenetic analyses of many plant species, but are less frequently used to investigate within-species variability and phylogeography. In this study, we investigated genetic diversity of Fagus sylvatica, an important broadleaved tree species of European forests, based on complete chloroplast genomes of 18 individuals sampled widely across the species distribution. Our results confirm the hypothesis of a low cpDNA diversity in European beech. The chloroplast genome size was remarkably stable (158,428 ± 37 bp). The polymorphic markers, 12 microsatellites (SSR), four SNPs and one indel, were found only in the single copy regions, while inverted repeat regions were monomorphic both in terms of length and sequence, suggesting highly efficient suppression of mutation. The within-individual analysis of polymorphisms showed >9k of markers which were proportionally present in gene and non-gene areas. However, an investigation of the frequency of alternate alleles revealed that the source of this diversity originated likely from nuclear-encoded plastome remnants (NUPTs). Phylogeographic and Mantel correlation analysis based on the complete chloroplast genomes exhibited clustering of individuals according to geographic distance in the first distance class, suggesting that the novel markers and in particular the cpSSRs could provide a more detailed picture of beech population structure in Central Europe.
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Buaya AT, Scholz B, Thines M. A New Marine Species of Miracula ( Oomycota) Parasitic to Minidiscus sp. in Iceland †. MYCOBIOLOGY 2021; 49:355-362. [PMID: 34512079 PMCID: PMC8409938 DOI: 10.1080/12298093.2021.1952813] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 06/29/2021] [Accepted: 07/05/2021] [Indexed: 06/13/2023]
Abstract
Obligate endoparasitic oomycetes are known to ubiquitously occur in marine and freshwater diatoms, but their diversity is still largely unexplored. Many of these parasitoids are members of the early-diverging oomycete lineages (Miracula, Diatomophthora), others are within the Leptomitales of the Saprolegniomycetes (Ectrogella, Lagenisma) and some have been described in the Peronosporomycetes (Aphanomycopsis, Lagenidium). Even though some species have been recently described and two new genera were introduced (Miracula and Diatomophthora), the phylogeny and taxonomy of most of these organisms remain unresolved. This is contrasted by the high number of sequences from unclassified species, as recently revealed from environmental sequencing, suggesting the presence of several undiscovered species. In this study, a new species of Miracula is reported from a marine centric diatom (Minidiscus sp.) isolated from Skagaströnd harbor in Northwest Iceland. The morphology and life cycle traits of this novel oomycete parasite are described herein, and its taxonomic placement within the genus Miracula is confirmed by molecular phylogeny. As it cannot be assigned to any previously described species, it is introduced as Miracula islandica in this study. The genus Miracula thus contains three described holocarpic species (M. helgolandica, M. islandica, M. moenusica) to which likely additional species will need to be added in the future, considering the presence of several lineages known only from environmental sequencing that clustered within the Miracula clade.
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Mirzaee MR, Ploch S, Thines M. A new desert-dwelling oomycete, Pustula persica sp. nov., on Gymnarrhena micrantha ( Asteraceae) from Iran. MYCOSCIENCE 2021; 62:239-243. [PMID: 37092169 PMCID: PMC9721518 DOI: 10.47371/mycosci.2021.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 03/16/2021] [Accepted: 03/16/2021] [Indexed: 11/16/2022]
Abstract
The obligate biotrophic oomycete genus Pustula is one of the four major linages of white blister rusts (Albuginaceae) identified so far. Species of the genus Pustula cause white blister rust on numerous genera in the asterids, represented by several phylogenetically distinct genus-specific lineages, most of which still await formal description. Thus, the observation of the species of Pustula on the Asteraceae subfamily Gymnorhenoideae pointed out to the existence of a hitherto undescribed species. By the morphological and molecular phylogenetic investigation conducted in this study it is concluded that the pathogen on Gymnarrhena micrantha from Iran indeed represents a hitherto unknown species and is described as P. persica. This species has apparently adapted to desert condition and is, after Albugo arenosa, the second species of white blister rust from Iranian deserts, highlighting the adaptability of white blister rusts to hot and dry habitats.
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Nowicki M, Hadziabdic D, Trigiano RN, Boggess SL, Kanetis L, Wadl PA, Ojiambo PS, Cubeta MA, Spring O, Thines M, Runge F, Scheffler BE. "Jumping Jack": Genomic Microsatellites Underscore the Distinctiveness of Closely Related Pseudoperonospora cubensis and Pseudoperonospora humuli and Provide New Insights Into Their Evolutionary Past. Front Microbiol 2021; 12:686759. [PMID: 34335513 PMCID: PMC8317435 DOI: 10.3389/fmicb.2021.686759] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 06/09/2021] [Indexed: 11/13/2022] Open
Abstract
Downy mildews caused by obligate biotrophic oomycetes result in severe crop losses worldwide. Among these pathogens, Pseudoperonospora cubensis and P. humuli, two closely related oomycetes, adversely affect cucurbits and hop, respectively. Discordant hypotheses concerning their taxonomic relationships have been proposed based on host-pathogen interactions and specificity evidence and gene sequences of a few individuals, but population genetics evidence supporting these scenarios is missing. Furthermore, nuclear and mitochondrial regions of both pathogens have been analyzed using microsatellites and phylogenetically informative molecular markers, but extensive comparative population genetics research has not been done. Here, we genotyped 138 current and historical herbarium specimens of those two taxa using microsatellites (SSRs). Our goals were to assess genetic diversity and spatial distribution, to infer the evolutionary history of P. cubensis and P. humuli, and to visualize genome-scale organizational relationship between both pathogens. High genetic diversity, modest gene flow, and presence of population structure, particularly in P. cubensis, were observed. When tested for cross-amplification, 20 out of 27 P. cubensis-derived gSSRs cross-amplified DNA of P. humuli individuals, but few amplified DNA of downy mildew pathogens from related genera. Collectively, our analyses provided a definite argument for the hypothesis that both pathogens are distinct species, and suggested further speciation in the P. cubensis complex.
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Pfenninger M, Reuss F, Kiebler A, Schönnenbeck P, Caliendo C, Gerber S, Cocchiararo B, Reuter S, Blüthgen N, Mody K, Mishra B, Bálint M, Thines M, Feldmeyer B. Genomic basis for drought resistance in European beech forests threatened by climate change. eLife 2021; 10:e65532. [PMID: 34132196 PMCID: PMC8266386 DOI: 10.7554/elife.65532] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 06/07/2021] [Indexed: 12/30/2022] Open
Abstract
In the course of global climate change, Central Europe is experiencing more frequent and prolonged periods of drought. The drought years 2018 and 2019 affected European beeches (Fagus sylvatica L.) differently: even in the same stand, drought-damaged trees neighboured healthy trees, suggesting that the genotype rather than the environment was responsible for this conspicuous pattern. We used this natural experiment to study the genomic basis of drought resistance with Pool-GWAS. Contrasting the extreme phenotypes identified 106 significantly associated single-nucleotide polymorphisms (SNPs) throughout the genome. Most annotated genes with associated SNPs (>70%) were previously implicated in the drought reaction of plants. Non-synonymous substitutions led either to a functional amino acid exchange or premature termination. An SNP assay with 70 loci allowed predicting drought phenotype in 98.6% of a validation sample of 92 trees. Drought resistance in European beech is a moderately polygenic trait that should respond well to natural selection, selective management, and breeding.
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Aime MC, Miller AN, Aoki T, Bensch K, Cai L, Crous PW, Hawksworth DL, Hyde KD, Kirk PM, Lücking R, May TW, Malosso E, Redhead SA, Rossman AY, Stadler M, Thines M, Yurkov AM, Zhang N, Schoch CL. How to publish a new fungal species, or name, version 3.0. IMA Fungus 2021; 12:11. [PMID: 33934723 PMCID: PMC8091500 DOI: 10.1186/s43008-021-00063-1] [Citation(s) in RCA: 71] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 04/08/2021] [Indexed: 12/19/2022] Open
Abstract
It is now a decade since The International Commission on the Taxonomy of Fungi (ICTF) produced an overview of requirements and best practices for describing a new fungal species. In the meantime the International Code of Nomenclature for algae, fungi, and plants (ICNafp) has changed from its former name (the International Code of Botanical Nomenclature) and introduced new formal requirements for valid publication of species scientific names, including the separation of provisions specific to Fungi and organisms treated as fungi in a new Chapter F. Equally transformative have been changes in the data collection, data dissemination, and analytical tools available to mycologists. This paper provides an updated and expanded discussion of current publication requirements along with best practices for the description of new fungal species and publication of new names and for improving accessibility of their associated metadata that have developed over the last 10 years. Additionally, we provide: (1) model papers for different fungal groups and circumstances; (2) a checklist to simplify meeting (i) the requirements of the ICNafp to ensure the effective, valid and legitimate publication of names of new taxa, and (ii) minimally accepted standards for description; and, (3) templates for preparing standardized species descriptions.
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Schurack S, Depotter JRL, Gupta D, Thines M, Doehlemann G. Comparative transcriptome profiling identifies maize line specificity of fungal effectors in the maize-Ustilago maydis interaction. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 106:733-752. [PMID: 33570802 DOI: 10.1111/tpj.15195] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 02/03/2021] [Accepted: 02/08/2021] [Indexed: 05/20/2023]
Abstract
The biotrophic pathogen Ustilago maydis causes smut disease on maize (Zea mays) and induces the formation of tumours on all aerial parts of the plant. Unlike in other biotrophic interactions, no gene-for-gene interactions have been identified in the maize-U. maydis pathosystem. Thus, maize resistance to U. maydis is considered a polygenic, quantitative trait. Here, we study the molecular mechanisms of quantitative disease resistance (QDR) in maize, and how U. maydis interferes with its components. Based on quantitative scoring of disease symptoms in 26 maize lines, we performed an RNA sequencing (RNA-Seq) analysis of six U. maydis-infected maize lines of highly distinct resistance levels. The different maize lines showed specific responses of diverse cellular processes to U. maydis infection. For U. maydis, our analysis identified 406 genes being differentially expressed between maize lines, of which 102 encode predicted effector proteins. Based on this analysis, we generated U. maydis CRISPR/Cas9 knock-out mutants for selected candidate effector sets. After infections of different maize lines with the fungal mutants, RNA-Seq analysis identified effectors with quantitative, maize line-specific virulence functions, and revealed auxin-related processes as a possible target for one of them. Thus, we show that both transcriptional activity and virulence function of fungal effector genes are modified according to the infected maize line, providing insights into the molecular mechanisms underlying QDR in the maize-U. maydis interaction.
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Lücking R, Aime MC, Robbertse B, Miller AN, Aoki T, Ariyawansa HA, Cardinali G, Crous PW, Druzhinina IS, Geiser DM, Hawksworth DL, Hyde KD, Irinyi L, Jeewon R, Johnston PR, Kirk PM, Malosso E, May TW, Meyer W, Nilsson HR, Öpik M, Robert V, Stadler M, Thines M, Vu D, Yurkov AM, Zhang N, Schoch CL. Fungal taxonomy and sequence-based nomenclature. Nat Microbiol 2021; 6:540-548. [PMID: 33903746 PMCID: PMC10116568 DOI: 10.1038/s41564-021-00888-x] [Citation(s) in RCA: 81] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 03/05/2021] [Indexed: 02/02/2023]
Abstract
The identification and proper naming of microfungi, in particular plant, animal and human pathogens, remains challenging. Molecular identification is becoming the default approach for many fungal groups, and environmental metabarcoding is contributing an increasing amount of sequence data documenting fungal diversity on a global scale. This includes lineages represented only by sequence data. At present, these taxa cannot be formally described under the current nomenclature rules. By considering approaches used in bacterial taxonomy, we propose solutions for the nomenclature of taxa known only from sequences to facilitate consistent reporting and communication in the literature and public sequence repositories.
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Langer JAF, Sharma R, Nam B, Hanic L, Boersma M, Schwenk K, Thines M. Cox2 community barcoding at Prince Edward Island reveals long-distance dispersal of a downy mildew species and potentially marine members of the Saprolegniaceae. Mycol Prog 2021. [DOI: 10.1007/s11557-021-01687-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AbstractMarine oomycetes are highly diverse, globally distributed, and play key roles in marine food webs as decomposers, food source, and parasites. Despite their potential importance in global ocean ecosystems, marine oomycetes are comparatively little studied. Here, we tested if the primer pair cox2F_Hud and cox2-RC4, which is already well-established for phylogenetic investigations of terrestrial oomycetes, can also be used for high-throughput community barcoding. Community barcoding of a plankton sample from Brudenell River (Prince Edward Island, Canada), revealed six distinct oomycete OTU clusters. Two of these clusters corresponded to members of the Peronosporaceae—one could be assigned to Peronospora verna, an obligate biotrophic pathogen of the terrestrial plant Veronica serpyllifolia and related species, the other was closely related to Globisporangium rostratum. While the detection of the former in the sample is likely due to long-distance dispersal from the island, the latter might be a bona fide marine species, as several cultivable species of the Peronosporaceae are known to withstand high salt concentrations. Two OTU lineages could be assigned to the Saprolegniaceae. While these might represent marine species of the otherwise terrestrial genus, it is also conceivable that they were introduced on detritus from the island. Two additional OTU clusters were grouped with the early-diverging oomycete lineages but could not be assigned to a specific family. This reflects the current underrepresentation of cox2 sequence data which will hopefully improve with the increasing interest in marine oomycetes.
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Crous P, Lombard L, Sandoval-Denis M, Seifert K, Schroers HJ, Chaverri P, Gené J, Guarro J, Hirooka Y, Bensch K, Kema G, Lamprecht S, Cai L, Rossman A, Stadler M, Summerbell R, Taylor J, Ploch S, Visagie C, Yilmaz N, Frisvad J, Abdel-Azeem A, Abdollahzadeh J, Abdolrasouli A, Akulov A, Alberts J, Araújo J, Ariyawansa H, Bakhshi M, Bendiksby M, Ben Hadj Amor A, Bezerra J, Boekhout T, Câmara M, Carbia M, Cardinali G, Castañeda-Ruiz R, Celis A, Chaturvedi V, Collemare J, Croll D, Damm U, Decock C, de Vries R, Ezekiel C, Fan X, Fernández N, Gaya E, González C, Gramaje D, Groenewald J, Grube M, Guevara-Suarez M, Gupta V, Guarnaccia V, Haddaji A, Hagen F, Haelewaters D, Hansen K, Hashimoto A, Hernández-Restrepo M, Houbraken J, Hubka V, Hyde K, Iturriaga T, Jeewon R, Johnston P, Jurjević Ž, Karalti İ, Korsten L, Kuramae E, Kušan I, Labuda R, Lawrence D, Lee H, Lechat C, Li H, Litovka Y, Maharachchikumbura S, Marin-Felix Y, Matio Kemkuignou B, Matočec N, McTaggart A, Mlčoch P, Mugnai L, Nakashima C, Nilsson R, Noumeur S, Pavlov I, Peralta M, Phillips A, Pitt J, Polizzi G, Quaedvlieg W, Rajeshkumar K, Restrepo S, Rhaiem A, Robert J, Robert V, Rodrigues A, Salgado-Salazar C, Samson R, Santos A, Shivas R, Souza-Motta C, Sun G, Swart W, Szoke S, Tan Y, Taylor J, Taylor P, Tiago P, Váczy K, van de Wiele N, van der Merwe N, Verkley G, Vieira W, Vizzini A, Weir B, Wijayawardene N, Xia J, Yáñez-Morales M, Yurkov A, Zamora J, Zare R, Zhang C, Thines M. Fusarium: more than a node or a foot-shaped basal cell. Stud Mycol 2021; 98:100116. [PMID: 34466168 PMCID: PMC8379525 DOI: 10.1016/j.simyco.2021.100116] [Citation(s) in RCA: 97] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Recent publications have argued that there are potentially serious consequences for researchers in recognising distinct genera in the terminal fusarioid clade of the family Nectriaceae. Thus, an alternate hypothesis, namely a very broad concept of the genus Fusarium was proposed. In doing so, however, a significant body of data that supports distinct genera in Nectriaceae based on morphology, biology, and phylogeny is disregarded. A DNA phylogeny based on 19 orthologous protein-coding genes was presented to support a very broad concept of Fusarium at the F1 node in Nectriaceae. Here, we demonstrate that re-analyses of this dataset show that all 19 genes support the F3 node that represents Fusarium sensu stricto as defined by F. sambucinum (sexual morph synonym Gibberella pulicaris). The backbone of the phylogeny is resolved by the concatenated alignment, but only six of the 19 genes fully support the F1 node, representing the broad circumscription of Fusarium. Furthermore, a re-analysis of the concatenated dataset revealed alternate topologies in different phylogenetic algorithms, highlighting the deep divergence and unresolved placement of various Nectriaceae lineages proposed as members of Fusarium. Species of Fusarium s. str. are characterised by Gibberella sexual morphs, asexual morphs with thin- or thick-walled macroconidia that have variously shaped apical and basal cells, and trichothecene mycotoxin production, which separates them from other fusarioid genera. Here we show that the Wollenweber concept of Fusarium presently accounts for 20 segregate genera with clear-cut synapomorphic traits, and that fusarioid macroconidia represent a character that has been gained or lost multiple times throughout Nectriaceae. Thus, the very broad circumscription of Fusarium is blurry and without apparent synapomorphies, and does not include all genera with fusarium-like macroconidia, which are spread throughout Nectriaceae (e.g., Cosmosporella, Macroconia, Microcera). In this study four new genera are introduced, along with 18 new species and 16 new combinations. These names convey information about relationships, morphology, and ecological preference that would otherwise be lost in a broader definition of Fusarium. To assist users to correctly identify fusarioid genera and species, we introduce a new online identification database, Fusarioid-ID, accessible at www.fusarium.org. The database comprises partial sequences from multiple genes commonly used to identify fusarioid taxa (act1, CaM, his3, rpb1, rpb2, tef1, tub2, ITS, and LSU). In this paper, we also present a nomenclator of names that have been introduced in Fusarium up to January 2021 as well as their current status, types, and diagnostic DNA barcode data. In this study, researchers from 46 countries, representing taxonomists, plant pathologists, medical mycologists, quarantine officials, regulatory agencies, and students, strongly support the application and use of a more precisely delimited Fusarium (= Gibberella) concept to accommodate taxa from the robust monophyletic node F3 on the basis of a well-defined and unique combination of morphological and biochemical features. This F3 node includes, among others, species of the F. fujikuroi, F. incarnatum-equiseti, F. oxysporum, and F. sambucinum species complexes, but not species of Bisifusarium [F. dimerum species complex (SC)], Cyanonectria (F. buxicola SC), Geejayessia (F. staphyleae SC), Neocosmospora (F. solani SC) or Rectifusarium (F. ventricosum SC). The present study represents the first step to generating a new online monograph of Fusarium and allied fusarioid genera (www.fusarium.org).
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Key Words
- Apiognomonia platani (Lév.) L. Lombard
- Atractium ciliatum Link
- Atractium pallidum Bonord.
- Calloria tremelloides (Grev.) L. Lombard
- Cephalosporium sacchari E.J. Butler
- Cosmosporella cavisperma (Corda) Sand.-Den., L. Lombard & Crous
- Cylindrodendrum orthosporum (Sacc. & P. Syd.) L. Lombard
- Dialonectria volutella (Ellis & Everh.) L. Lombard & Sand.-Den.
- Fusarium aeruginosum Delacr.
- Fusarium agaricorum Sarrazin
- Fusarium albidoviolaceum Dasz.
- Fusarium aleyrodis Petch
- Fusarium amentorum Lacroix
- Fusarium annuum Leonian
- Fusarium arcuatum Berk. & M.A. Curtis
- Fusarium aridum O.A. Pratt
- Fusarium armeniacum (G.A. Forbes et al.) L.W. Burgess & Summerell
- Fusarium arthrosporioides Sherb.
- Fusarium asparagi Delacr.
- Fusarium batatas Wollenw.
- Fusarium biforme Sherb.
- Fusarium buharicum Jacz. ex Babajan & Teterevn.-Babajan
- Fusarium cactacearum Pasin. & Buzz.-Trav.
- Fusarium cacti-maxonii Pasin. & Buzz.-Trav.
- Fusarium caudatum Wollenw.
- Fusarium cavispermum Corda
- Fusarium cepae Hanzawa
- Fusarium cesatii Rabenh.
- Fusarium citriforme Jamal.
- Fusarium citrinum Wollenw.
- Fusarium citrulli Taubenh.
- Fusarium clavatum Sherb.
- Fusarium coccinellum Kalchbr.
- Fusarium cromyophthoron Sideris
- Fusarium cucurbitae Taubenh.
- Fusarium cuneiforme Sherb.
- Fusarium delacroixii Sacc.
- Fusarium dimerum var. nectrioides Wollenw.
- Fusarium echinatum Sand.-Den. & G.J. Marais
- Fusarium epicoccum McAlpine
- Fusarium eucheliae Sartory, R. Sartory & J. Mey.
- Fusarium fissum Peyl
- Fusarium flocciferum Corda
- Fusarium gemmiperda Aderh.
- Fusarium genevense Dasz.
- Fusarium graminearum Schwabe
- Fusarium graminum Corda
- Fusarium heterosporioides Fautrey
- Fusarium heterosporum Nees & T. Nees
- Fusarium idahoanum O.A. Pratt
- Fusarium juruanum Henn.
- Fusarium lanceolatum O.A. Pratt
- Fusarium lateritium Nees
- Fusarium loncheceras Sideris
- Fusarium longipes Wollenw. & Reinking
- Fusarium lyarnte J.L. Walsh, Sangal., L.W. Burgess, E.C.Y. Liew & Summerell
- Fusarium malvacearum Taubenh.
- Fusarium martii f. phaseoli Burkh.
- Fusarium muentzii Delacr.
- Fusarium nigrum O.A. Pratt
- Fusarium oxysporum var. asclerotium Sherb.
- Fusarium palczewskii Jacz.
- Fusarium palustre W.H. Elmer & Marra
- Fusarium polymorphum Matr.
- Fusarium poolense Taubenh.
- Fusarium prieskaense G.J. Marais & Sand.-Den.
- Fusarium prunorum McAlpine
- Fusarium pusillum Wollenw.
- Fusarium putrefaciens Osterw.
- Fusarium redolens Wollenw.
- Fusarium reticulatum Mont.
- Fusarium rhizochromatistes Sideris
- Fusarium rhizophilum Corda
- Fusarium rhodellum McAlpine
- Fusarium roesleri Thüm.
- Fusarium rostratum Appel & Wollenw.
- Fusarium rubiginosum Appel & Wollenw.
- Fusarium rubrum Parav.
- Fusarium samoense Gehrm.
- Fusarium scirpi Lambotte & Fautrey
- Fusarium secalis Jacz.
- Fusarium spinaciae Hungerf.
- Fusarium sporotrichioides Sherb.
- Fusarium stercoris Fuckel
- Fusarium stilboides Wollenw.
- Fusarium stillatum De Not. ex Sacc.
- Fusarium sublunatum Reinking
- Fusarium succisae Schröt. ex Sacc.
- Fusarium tabacivorum Delacr.
- Fusarium trichothecioides Wollenw.
- Fusarium tritici Liebman
- Fusarium tuberivorum Wilcox & G.K. Link
- Fusarium tumidum var. humi Reinking
- Fusarium ustilaginis Kellerm. & Swingle
- Fusarium viticola Thüm.
- Fusarium werrikimbe J.L. Walsh, L.W. Burgess, E.C.Y. Liew & B.A. Summerell
- Fusarium willkommii Lindau
- Fusarium xylarioides Steyaert
- Fusarium zygopetali Delacr.
- Fusicolla meniscoidea L. Lombard & Sand.-Den.
- Fusicolla quarantenae J.D.P. Bezerra, Sand.-Den., Crous & Souza-Motta
- Fusicolla sporellula Sand.-Den. & L. Lombard
- Fusisporium andropogonis Cooke ex Thüm.
- Fusisporium anthophilum A. Braun
- Fusisporium arundinis Corda
- Fusisporium avenaceum Fr.
- Fusisporium clypeaster Corda
- Fusisporium culmorum Wm.G. Sm.
- Fusisporium didymum Harting
- Fusisporium elasticae Thüm.
- Fusisporium episphaericum Cooke & Ellis
- Fusisporium flavidum Bonord.
- Fusisporium hordei Wm.G. Sm.
- Fusisporium incarnatum Roberge ex Desm.
- Fusisporium lolii Wm.G. Sm.
- Fusisporium pandani Corda
- Gibberella phyllostachydicola W. Yamam.
- Hymenella aurea (Corda) L. Lombard
- Hymenella spermogoniopsis (Jul. Müll.) L. Lombard & Sand.-Den.
- Luteonectria Sand.-Den., L. Lombard, Schroers & Rossman
- Luteonectria albida (Rossman) Sand.-Den. & L. Lombard
- Luteonectria nematophila (Nirenberg & Hagedorn) Sand.-Den. & L. Lombard
- Macroconia bulbipes Crous & Sand.-Den.
- Macroconia phlogioides Sand.-Den. & Crous
- Menispora penicillata Harz
- Multi-gene phylogeny
- Mycotoxins
- Nectriaceae
- Neocosmospora
- Neocosmospora epipeda Quaedvl. & Sand.-Den.
- Neocosmospora floridana (T. Aoki et al.) L. Lombard & Sand.-Den.
- Neocosmospora merkxiana Quaedvl. & Sand.-Den.
- Neocosmospora neerlandica Crous & Sand.-Den.
- Neocosmospora nelsonii Crous & Sand.-Den.
- Neocosmospora obliquiseptata (T. Aoki et al.) L. Lombard & Sand.-Den.
- Neocosmospora pseudopisi Sand.-Den. & L. Lombard
- Neocosmospora rekana (Lynn & Marinc.) L. Lombard & Sand.-Den.
- Neocosmospora tuaranensis (T. Aoki et al.) L. Lombard & Sand.-Den.
- Nothofusarium Crous, Sand.-Den. & L. Lombard
- Nothofusarium devonianum L. Lombard, Crous & Sand.-Den.
- Novel taxa
- Pathogen
- Scolecofusarium L. Lombard, Sand.-Den. & Crous
- Scolecofusarium ciliatum (Link) L. Lombard, Sand.-Den. & Crous
- Selenosporium equiseti Corda
- Selenosporium hippocastani Corda
- Selenosporium sarcochroum Desm
- Selenosporium urticearum Corda.
- Setofusarium (Nirenberg & Samuels) Crous & Sand.-Den.
- Setofusarium setosum (Samuels & Nirenberg) Sand.-Den. & Crous.
- Sphaeria sanguinea var. cicatricum Berk.
- Sporotrichum poae Peck.
- Stylonectria corniculata Gräfenhan, Crous & Sand.-Den.
- Stylonectria hetmanica Akulov, Crous & Sand.-Den.
- Taxonomy
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Davis WJ, Ko M, Ocenar JR, Romberg MK, Thines M, Crouch JA. Peronospora kuewa, sp. nov., a new downy mildew species infecting the endangered Hawaiian plant Plantago princeps var. princeps. Mycologia 2021; 113:643-652. [PMID: 33734033 DOI: 10.1080/00275514.2021.1872869] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Plantago princeps var. princeps is an endangered native Hawaiian plant, and part of the recovery plan includes repopulation using plants grown in a nursery. However, disease pressure from downy mildew is hindering repopulation efforts. The organism associated with the downy mildew was determined to be a Peronospora species with brown, ellipsoid conidia measuring 21 by 16 µm on average, which was morphologically different from validly described species of Peronospora that infect Plantago species, but it was morphologically similar to the invalidly published species Peronospora lanceolatae (Art. 40.1). Comparison of mitochondrial cytochrome oxidase subunit I (cox1), mitochondrial cytochrome oxidase subunit II (cox2), nuclear internal transcribed spacer (ITS), and nuclear 28S rRNA D1-D2 (28S) loci revealed the unknown Peronospora to be molecularly divergent from Peronospora alta and Peronsopora plantaginis, but very similar to Peronospora from Plantago lanceolata, the type host of P. lanceolatae. Phylogenetic trees inferred with maximum likelihood and Bayesian inference from a concatenated alignmaent and individual gene trees confirmed the divergence of the unknown Peronospora from P. alta and P. plantaginis and its similarity to P. lanceolatae. However, attempts to inoculate Plantago lanceolata with the strain from Plantago princeps var. princeps were unsuccessful, which, in conjunction with divergence in ITS, suggests that the unknown Peronospora is specific to Plantago princeps var. princeps. Herein, the Peronospora strain on Plantago princeps var. princeps is described as the new species Peronospora kuewa based on morphology, molecular phylogenetics, and host specificity. In addition, Peronospora gaponenkoae is described here to honor Nina Ivanova Gaponenko on the basis of her description of P. lanceolatae.
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Buaya AT, Scholz B, Thines M. Sirolpidium bryopsidis, a parasite of green algae, is probably conspecific with Pontisma lagenidioides, a parasite of red algae. Fungal Syst Evol 2021; 7:223-231. [PMID: 34124625 PMCID: PMC8165961 DOI: 10.3114/fuse.2021.07.11] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 02/22/2021] [Indexed: 11/10/2022] Open
Abstract
The genus Sirolpidium (Sirolpidiaceae) of the Oomycota includes several species of holocarpic obligate aquatic parasites. These organisms are widely occurring in marine and freshwater habitats, mostly infecting filamentous green algae. Presently, all species are only known from their morphology and descriptive life cycle traits. None of the seven species classified in Sirolpidium, including the type species, S. bryopsidis, has been rediscovered and studied for their molecular phylogeny, so far. Originally, the genus was established to accommodate all parasites of filamentous marine green algae. In the past few decades, however, Sirolpidium has undergone multiple taxonomic revisions and several species parasitic in other host groups were added to the genus. While the phylogeny of the marine rhodophyte- and phaeophyte-infecting genera Pontisma and Eurychasma, respectively, has only been resolved recently, the taxonomic placement of the chlorophyte-infecting genus Sirolpidium remained unresolved. In the present study, we report the phylogenetic placement of Sirolpidium bryopsidis infecting the filamentous marine green algae Capsosiphon fulvescens sampled from Skagaströnd in Northwest Iceland. Phylogenetic reconstructions revealed that S. bryopsidis is either conspecific or at least very closely related to the type species of Pontisma, Po. lagenidioides. Consequently, the type species of genus Sirolpidium, S. bryopsidis, is reclassified to Pontisma. Further infection trials are needed to determine if Po. bryopsidis and Po. lagenidioides are conspecific or closely related. In either case, the apparently recent host jump from red to green algae is remarkable, as it opens the possibility for radiation in a largely divergent eukaryotic lineage. Citation: Buaya AT, Scholz B, Thines M (2021). Sirolpidium bryopsidis, a parasite of green algae, is probably conspecific with Pontisma lagenidioides, a parasite of red algae. Fungal Systematics and Evolution7: 223–231. doi: 10.3114/fuse.2021.07.11
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Thines M, Aoki T, Crous PW, Hyde KD, Lücking R, Malosso E, May TW, Miller AN, Redhead SA, Yurkov AM, Hawksworth DL. Setting scientific names at all taxonomic ranks in italics facilitates their quick recognition in scientific papers. IMA Fungus 2020; 11:25. [PMID: 33292779 PMCID: PMC7670697 DOI: 10.1186/s43008-020-00048-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 10/27/2020] [Indexed: 11/15/2022] Open
Abstract
It is common practice in scientific journals to print genus and species names in italics. This is not only historical as species names were traditionally derived from Greek or Latin. Importantly, it also facilitates the rapid recognition of genus and species names when skimming through manuscripts. However, names above the genus level are not always italicized, except in some journals which have adopted this practice for all scientific names. Since scientific names treated under the various Codes of nomenclature are without exception treated as Latin, there is no reason why names above genus level should be handled differently, particularly as higher taxon names are becoming increasingly relevant in systematic and evolutionary studies and their italicization would aid the unambiguous recognition of formal scientific names distinguishing them from colloquial names. Several leading mycological and botanical journals have already adopted italics for names of all taxa regardless of rank over recent decades, as is the practice in the International Code of Nomenclature for algae, fungi, and plants, and we hereby recommend that this practice be taken up broadly in scientific journals and textbooks.
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Suharjo R, Swibawa IG, Prasetyo J, Fitriana Y, Danaatmadja Y, Budiawan A, Roberts S, Noorhajati N, Amad M, Thines M. Peronosclerospora australiensis is a synonym of P. maydis, which is widespread on Sumatra, and distinct from the most prevalent Java maize downy mildew pathogen. Mycol Prog 2020. [DOI: 10.1007/s11557-020-01628-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Abstract
This study was performed to identify Peronosclerospora species found in Indonesia based on sequence analysis of the cox2 gene. In addition, sequence data in total, 26 isolates of Peronosclerospora were investigated in this study. They were obtained from 7 provinces in Indonesia, namely Lampung, Jawa Timur, Jawa Barat, Sumatera Utara, Jawa Tengah, Yogyakarta, and Sulawesi Selatan. Sequence analysis of cox2 and phylogenetic inference were performed on all the 26 isolates. A set of primers developed in this study, PCOX2F and PCOX2R, was used for PCR amplification. Phylogenetic analyses showed that all the Indonesian isolates were divided into two groups. Group I contained 13 isolates; 9 isolates obtained from Lampung, 3 isolates from Sumatera Utara, and 1 isolate from Jawa Barat. Group II consisted of 13 isolates; 7 isolates from Jawa Timur, 2 isolates from Jawa Tengah, 1 isolate from Yogyakarta, and 3 isolates from Sulawesi Selatan. All the members of group I clustered with the ex-type sequence of P. australiensis. Meanwhile, all members of Group II formed the sister clade of isolates obtained from Timor-Leste and may represent P. maydis.
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Thines M, Buaya A, Ali T, Brand T. Peronospora aquilegiicola made its way to Germany: the start of a new pandemic? Mycol Prog 2020. [DOI: 10.1007/s11557-020-01596-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AbstractPeronospora aquilegiicola is a destructive pathogen of columbines and has wiped out most Aquilegia cultivars in several private and public gardens throughout Britain. The pathogen, which is native to East Asia was noticed in England and Wales in 2013 and quickly spread through the country, probably by infested plants or seeds. To our knowledge, the pathogen has so far not been reported from other parts of Europe. Here, we report the emergence of the pathogen in the northwest of Germany, based on morphological and phylogenetic evidence. As the pathogen was found in a garden in which no new columbines had been planted recently, we assume that the pathogen has already spread from its original point of introduction in Germany. This calls for an increased attention to the further spread of the pathogen and the eradication of infection spots to avoid the spread to naturally occurring columbines in Germany and to prevent another downy mildew from becoming a global threat, like Peronospora belbahrii and Plasmopara destructor, the downy mildews of basil and balsamines, respectively.
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Choi YJ, Görg M, Shin HD, Thines M. Plasmopara elegantissima sp. nov. (Oomycota, Peronosporales), a Downy Mildew Species Specialized to Impatiens textori (Balsaminaceae). MYCOBIOLOGY 2020; 48:304-312. [PMID: 32952413 PMCID: PMC7476525 DOI: 10.1080/12298093.2020.1788259] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 04/21/2020] [Accepted: 05/03/2020] [Indexed: 06/11/2023]
Abstract
Over the past 15 years, downy mildew became the most destructive foliar disease in cultivated Impatiens species (Balsaminaceae) worldwide. A previous study had revealed that the causal agent was not Plasmopara obducens (Oomycota, Peronosporales) but Plasmopara destructor on Impatiens walleriana, and Plasmopara velutina on Impatiens balsamina. This hints to a relatively high degree of specialization of Plasmopara on Balsaminaceae. Therefore, it was the aim of the present study to perform multigene phylogenetic analysis and detailed morphological investigation for several Korean downy mildew samples parasitic to cultivated I. walleriana, and I. balsamina, but also to a northeast Asian wild plant, Impatiens textori. It was revealed that I. textori harbors a new species, which is introduced and described here as Plasmopara elegantissima.
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Lücking R, Aime MC, Robbertse B, Miller AN, Ariyawansa HA, Aoki T, Cardinali G, Crous PW, Druzhinina IS, Geiser DM, Hawksworth DL, Hyde KD, Irinyi L, Jeewon R, Johnston PR, Kirk PM, Malosso E, May TW, Meyer W, Öpik M, Robert V, Stadler M, Thines M, Vu D, Yurkov AM, Zhang N, Schoch CL. Unambiguous identification of fungi: where do we stand and how accurate and precise is fungal DNA barcoding? IMA Fungus 2020; 11:14. [PMID: 32714773 PMCID: PMC7353689 DOI: 10.1186/s43008-020-00033-z] [Citation(s) in RCA: 185] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
True fungi (Fungi) and fungus-like organisms (e.g. Mycetozoa, Oomycota) constitute the second largest group of organisms based on global richness estimates, with around 3 million predicted species. Compared to plants and animals, fungi have simple body plans with often morphologically and ecologically obscure structures. This poses challenges for accurate and precise identifications. Here we provide a conceptual framework for the identification of fungi, encouraging the approach of integrative (polyphasic) taxonomy for species delimitation, i.e. the combination of genealogy (phylogeny), phenotype (including autecology), and reproductive biology (when feasible). This allows objective evaluation of diagnostic characters, either phenotypic or molecular or both. Verification of identifications is crucial but often neglected. Because of clade-specific evolutionary histories, there is currently no single tool for the identification of fungi, although DNA barcoding using the internal transcribed spacer (ITS) remains a first diagnosis, particularly in metabarcoding studies. Secondary DNA barcodes are increasingly implemented for groups where ITS does not provide sufficient precision. Issues of pairwise sequence similarity-based identifications and OTU clustering are discussed, and multiple sequence alignment-based phylogenetic approaches with subsequent verification are recommended as more accurate alternatives. In metabarcoding approaches, the trade-off between speed and accuracy and precision of molecular identifications must be carefully considered. Intragenomic variation of the ITS and other barcoding markers should be properly documented, as phylotype diversity is not necessarily a proxy of species richness. Important strategies to improve molecular identification of fungi are: (1) broadly document intraspecific and intragenomic variation of barcoding markers; (2) substantially expand sequence repositories, focusing on undersampled clades and missing taxa; (3) improve curation of sequence labels in primary repositories and substantially increase the number of sequences based on verified material; (4) link sequence data to digital information of voucher specimens including imagery. In parallel, technological improvements to genome sequencing offer promising alternatives to DNA barcoding in the future. Despite the prevalence of DNA-based fungal taxonomy, phenotype-based approaches remain an important strategy to catalog the global diversity of fungi and establish initial species hypotheses.
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Mishra B, Ploch S, Runge F, Schmuker A, Xia X, Gupta DK, Sharma R, Thines M. The Genome of Microthlaspi erraticum (Brassicaceae) Provides Insights Into the Adaptation to Highly Calcareous Soils. FRONTIERS IN PLANT SCIENCE 2020; 11:943. [PMID: 32719698 PMCID: PMC7350527 DOI: 10.3389/fpls.2020.00943] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 06/10/2020] [Indexed: 06/11/2023]
Abstract
Microthlaspi erraticum is widely distributed in temperate Eurasia, but restricted to Ca2+-rich habitats, predominantly on white Jurassic limestone, which is made up by calcium carbonate, with little other minerals. Thus, naturally occurring Microthlaspi erraticum individuals are confronted with a high concentration of Ca2+ ions while Mg2+ ion concentration is relatively low. As there is a competitive uptake between these two ions, adaptation to the soil condition can be expected. In this study, it was the aim to explore the genomic consequences of this adaptation by sequencing and analysing the genome of Microthlaspi erraticum. Its genome size is comparable with other diploid Brassicaceae, while more genes were predicted. Two Mg2+ transporters known to be expressed in roots were duplicated and one showed a significant degree of positive selection. It is speculated that this evolved due to the pressure to take up Mg2+ ions efficiently in the presence of an overwhelming amount of Ca2+ ions. Future studies on plants specialized on similar soils and affinity tests of the transporters are needed to provide unequivocal evidence for this hypothesis. If verified, the transporters found in this study might be useful for breeding Brassicaceae crops for higher yield on Ca2+-rich and Mg2+ -poor soils.
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Buaya A, Thines M. Diatomophthoraceae - a new family of olpidiopsis-like diatom parasitoids largely unrelated to Ectrogella. Fungal Syst Evol 2020; 5:113-118. [PMID: 32467917 PMCID: PMC7250014 DOI: 10.3114/fuse.2020.05.06] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The oomycete genus Ectrogella currently comprises a rather heterogeneous group of obligate endoparasitoids, mostly of diatoms and algae. Despite their widespread occurrence, little is known regarding the phylogenetic affinities of these bizarre organisms. Traditionally, the genus was included within the Saprolegniales, based on zoospore diplanetism and a saprolegnia/achlya-like zoospore discharge. The genus has undergone multiple re-definitions in the past, and has often been used largely indiscriminately for oomycetes forming sausage-like thalli in diatoms. While the phylogenetic affinity of the polyphyletic genus Olpidiopsis has recently been partially resolved, taxonomic placement of the genus Ectrogella remained unresolved, as no sequence data were available for species of this genus. In this study, we report the phylogenetic placement of Ectrogella bacillariacearum infecting the freshwater diatom Nitzschia sigmoidea. The phylogenetic reconstruction shows that Ectrogella bacillariacearum is grouped among the early diverging lineages of the Saprolegniomycetes with high support, and is unrelated to the monophyletic diatom-infecting olpidiopsis-like species. As these species are neither related to Ectrogella, nor to the early diverging lineages of Olpidiopsis s. str. and Miracula, they are placed in a new genus, Diatomophthora, in the present study.
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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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Buaya AT, Thines M. Bolbea parasitica gen. et sp. nov., a cultivable holocarpic parasitoid of the early-diverging Saprolegniomycetes. Fungal Syst Evol 2020; 6:129-137. [PMID: 32904153 PMCID: PMC7451777 DOI: 10.3114/fuse.2020.06.07] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Holocarpic oomycetes convert their entire cytoplasm into zoospores and thus do not form dedicated sporangia or hyphal compartments for asexual reproduction. The majority of holocarpic oomycetes are obligate parasites and parasitoids of a diverse suite of organisms, among them green and red algae, brown seaweeds, diatoms, fungi, oomycetes and invertebrates. Most of them are found among the early diverging oomycetes or the Peronosporomycetes, and some in the early-diverging Saprolegniomycetes (Leptomitales). The obligate parasitism renders it difficult to study some of these organisms. Only a few members of the genus Haliphthoross. l. have been cultured without their hosts, and of the parasitoid Leptomitales, some transient cultures have been established, which are difficult to maintain. Here, the cultivation of a new holocarpic oomycete genus of the Leptomitales, Bolbea, is presented. Bolbea is parasitic to ostracods, is readily cultivable on malt extract agar, and upon contact with water converts its cytoplasm into zoospores. Its morphology and phylogenetic relationships are reported. Due to the ease of cultivation and the ready triggering of zoospore development, similar to some lagenidiaceous oomycetes, the species could be a promising model to study sporulation processes in detail.
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