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Ben Amara W, Djebbi S, Khemakhem MM. Evolutionary History of the DD41D Family of Tc1/Mariner Transposons in Two Mayetiola Species. Biochem Genet 2024:10.1007/s10528-024-10898-z. [PMID: 39117934 DOI: 10.1007/s10528-024-10898-z] [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: 11/18/2023] [Accepted: 07/29/2024] [Indexed: 08/10/2024]
Abstract
Tc1/mariner elements are ubiquitous in eukaryotic genomes including insects. They are diverse and divided into families and sub-families. The DD34D family including mauritiana and irritans subfamilies have already been identified in two closely related species of Cecidomyiids M. destructor and M. hordei. In the current study the de novo and similarity-based methods allowed the identification for the first time of seven consensuses in M. destructor and two consensuses in M. hordei belonging to DD41D family whereas the in vitro method allowed the amplification of two and three elements in these two species respectively. Most of identified elements accumulated different mutations and long deletions spanning the N-terminal region of the transposase. Phylogenetic analyses showed that the DD41D elements were clustered in two groups belonging to rosa and Long-TIR subfamilies. The age estimation of the last transposition events of the identified Tc1/mariner elements in M. destructor showed different evolutionary histories. Indeed, irritans elements have oscillated between periods of silencing and reappearance while rosa and mauritiana elements have shown regular activity with large recent bursts. The study of insertion sites showed that they are mostly intronic and that some recently transposed elements occurred in genes linked to putative DNA-binding domains and enzymes involved in metabolic chains. Thus, this study gave evidence of the existence of DD41D family in two Mayetiola species and an insight on their evolutionary history.
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Affiliation(s)
- Wiem Ben Amara
- Laboratory of Biochemistry and Biotechnology (LR01ES05), Faculty of Sciences of Tunis, University of Tunis El Manar, 1068, Tunis, Tunisia
| | - Salma Djebbi
- Laboratory of Biochemistry and Biotechnology (LR01ES05), Faculty of Sciences of Tunis, University of Tunis El Manar, 1068, Tunis, Tunisia
| | - Maha Mezghani Khemakhem
- Laboratory of Biochemistry and Biotechnology (LR01ES05), Faculty of Sciences of Tunis, University of Tunis El Manar, 1068, Tunis, Tunisia.
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Westerberg I, Ament-Velásquez SL, Vogan AA, Johannesson H. Evolutionary dynamics of the LTR-retrotransposon crapaud in the Podospora anserina species complex and the interaction with repeat-induced point mutations. Mob DNA 2024; 15:1. [PMID: 38218923 PMCID: PMC10787394 DOI: 10.1186/s13100-023-00311-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 12/22/2023] [Indexed: 01/15/2024] Open
Abstract
BACKGROUND The genome of the filamentous ascomycete Podospora anserina shows a relatively high abundance of retrotransposons compared to other interspersed repeats. The LTR-retrotransposon family crapaud is particularly abundant in the genome, and consists of multiple diverged sequence variations specifically localized in the 5' half of both long terminal repeats (LTRs). P. anserina is part of a recently diverged species-complex, which makes the system ideal to classify the crapaud family based on the observed LTR variation and to study the evolutionary dynamics, such as the diversification and bursts of the elements over recent evolutionary time. RESULTS We developed a sequence similarity network approach to classify the crapaud repeats of seven genomes representing the P. anserina species complex into 14 subfamilies. This method does not utilize a consensus sequence, but instead it connects any copies that share enough sequence similarity over a set sequence coverage. Based on phylogenetic analyses, we found that the crapaud repeats likely diversified in the ancestor of the complex and have had activity at different time points for different subfamilies. Furthermore, while we hypothesized that the evolution into multiple subfamilies could have been a direct effect of escaping the genome defense system of repeat induced point mutations, we found this not to be the case. CONCLUSIONS Our study contributes to the development of methods to classify transposable elements in fungi, and also highlights the intricate patterns of retrotransposon evolution over short timescales and under high mutational load caused by nucleotide-altering genome defense.
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Affiliation(s)
- Ivar Westerberg
- Department of Ecology, environmental and Plant Sciences, Stockholm University, Stockholm, 106 91, Sweden
| | - S Lorena Ament-Velásquez
- Division of Population Genetics, Department of Zoology, Stockholm University, Stockholm, 106 91, Sweden
| | - Aaron A Vogan
- Systematic Biology, Department of Organismal Biology, Uppsala University, Norbyvägen 18D, Uppsala, 752 36, Sweden.
| | - Hanna Johannesson
- Department of Ecology, environmental and Plant Sciences, Stockholm University, Stockholm, 106 91, Sweden.
- The Royal Swedish Academy of Sciences, Stockholm, 114 18, Sweden.
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Duhamel M, Hood ME, Rodríguez de la Vega RC, Giraud T. Dynamics of transposable element accumulation in the non-recombining regions of mating-type chromosomes in anther-smut fungi. Nat Commun 2023; 14:5692. [PMID: 37709766 PMCID: PMC10502011 DOI: 10.1038/s41467-023-41413-4] [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: 12/23/2022] [Accepted: 08/30/2023] [Indexed: 09/16/2023] Open
Abstract
In the absence of recombination, the number of transposable elements (TEs) increases due to less efficient selection, but the dynamics of such TE accumulations are not well characterized. Leveraging a dataset of 21 independent events of recombination cessation of different ages in mating-type chromosomes of Microbotryum fungi, we show that TEs rapidly accumulated in regions lacking recombination, but that TE content reached a plateau at ca. 50% of occupied base pairs by 1.5 million years following recombination suppression. The same TE superfamilies have expanded in independently evolved non-recombining regions, in particular rolling-circle replication elements (Helitrons). Long-terminal repeat (LTR) retrotransposons of the Copia and Ty3 superfamilies also expanded, through transposition bursts (distinguished from gene conversion based on LTR divergence), with both non-recombining regions and autosomes affected, suggesting that non-recombining regions constitute TE reservoirs. This study improves our knowledge of genome evolution by showing that TEs can accumulate through bursts, following non-linear decelerating dynamics.
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Affiliation(s)
- Marine Duhamel
- Ecologie Systématique Evolution, IDEEV, CNRS, Université Paris-Saclay, AgroParisTech, Bâtiment 680, 12 route RD128, 91190, Gif-sur-Yvette, France.
- Evolution der Pflanzen und Pilze, Ruhr-Universität Bochum, Universitätsstraße 150, 44780, Bochum, Germany.
| | - Michael E Hood
- Department of Biology, Amherst College, 01002-5000, Amherst, MA, USA
| | - Ricardo C Rodríguez de la Vega
- Ecologie Systématique Evolution, IDEEV, CNRS, Université Paris-Saclay, AgroParisTech, Bâtiment 680, 12 route RD128, 91190, Gif-sur-Yvette, France
| | - Tatiana Giraud
- Ecologie Systématique Evolution, IDEEV, CNRS, Université Paris-Saclay, AgroParisTech, Bâtiment 680, 12 route RD128, 91190, Gif-sur-Yvette, France
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Zaccaron AZ, Neill T, Corcoran J, Mahaffee WF, Stergiopoulos I. A chromosome-scale genome assembly of the grape powdery mildew pathogen Erysiphe necator reveals its genomic architecture and previously unknown features of its biology. mBio 2023; 14:e0064523. [PMID: 37341476 PMCID: PMC10470754 DOI: 10.1128/mbio.00645-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 04/13/2023] [Indexed: 06/22/2023] Open
Abstract
Erysiphe necator is an obligate fungal pathogen that causes grape powdery mildew, globally the most important disease on grapevines. Previous attempts to obtain a quality genome assembly for this pathogen were hindered by its high repetitive DNA content. Here, chromatin conformation capture (Hi-C) with long-read PacBio sequencing was combined to obtain a chromosome-scale assembly and a high-quality annotation for E. necator isolate EnFRAME01. The resulting 81.1 Mb genome assembly is 98% complete and consists of 34 scaffolds, 11 of which represent complete chromosomes. All chromosomes contain large centromeric-like regions and lack synteny to the 11 chromosomes of the cereal PM pathogen Blumeria graminis. Further analysis of their composition showed that repeats and transposable elements (TEs) occupy 62.7% of their content. TEs were almost evenly interspersed outside centromeric and telomeric regions and massively overlapped with regions of annotated genes, suggesting that they could have a significant functional impact. Abundant gene duplicates were observed as well, particularly in genes encoding candidate secreted effector proteins. Moreover, younger in age gene duplicates exhibited more relaxed selection pressure and were more likely to be located physically close in the genome than older duplicates. A total of 122 genes with copy number variations among six isolates of E. necator were also identified and were enriched in genes that were duplicated in EnFRAME01, indicating they may reflect an adaptive variation. Taken together, our study illuminates higher-order genomic architectural features of E. necator and provides a valuable resource for studying genomic structural variations in this pathogen. IMPORTANCE Grape powdery mildew caused by the ascomycete fungus Erysiphe necator is economically the most important and recurrent disease in vineyards across the world. The obligate biotrophic nature of E. necator hinders the use of typical genetic methods to elucidate its pathogenicity and adaptation to adverse conditions, and thus comparative genomics has been a major method to study its genome biology. However, the current reference genome of E. necator isolate C-strain is highly fragmented with many non-coding regions left unassembled. This incompleteness prohibits in-depth comparative genomic analyses and the study of genomic structural variations (SVs) that are known to affect several aspects of microbial life, including fitness, virulence, and host adaptation. By obtaining a chromosome-scale genome assembly and a high-quality gene annotation for E. necator, we reveal the organization of its chromosomal content, unearth previously unknown features of its biology, and provide a reference for studying genomic SVs in this pathogen.
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Affiliation(s)
- Alex Z. Zaccaron
- Department of Plant Pathology, University of California Davis, Davis, California, USA
| | - Tara Neill
- USDA-ARS, Horticultural Crops Disease and Pest Management Research Unit, Corvallis, Oregon, USA
| | - Jacob Corcoran
- USDA-ARS, Horticultural Crops Disease and Pest Management Research Unit, Corvallis, Oregon, USA
| | - Walter F. Mahaffee
- USDA-ARS, Horticultural Crops Disease and Pest Management Research Unit, Corvallis, Oregon, USA
| | - Ioannis Stergiopoulos
- Department of Plant Pathology, University of California Davis, Davis, California, USA
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Sobol MS, Hoshino T, Delgado V, Futagami T, Kadooka C, Inagaki F, Kiel Reese B. Genome characterization of two novel deep-sea sediment fungi, Penicillium pacificagyrus sp. nov. and Penicillium pacificasedimenti sp. nov., from South Pacific Gyre subseafloor sediments, highlights survivability. BMC Genomics 2023; 24:249. [PMID: 37165355 PMCID: PMC10173653 DOI: 10.1186/s12864-023-09320-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 04/18/2023] [Indexed: 05/12/2023] Open
Abstract
BACKGROUND Marine deep subsurface sediments were once thought to be devoid of eukaryotic life, but advances in molecular technology have unlocked the presence and activity of well-known closely related terrestrial and marine fungi. Commonly detected fungi in deep marine sediment environments includes Penicillium, Aspergillus, Cladosporium, Fusarium, and Schizophyllum, which could have important implications in carbon and nitrogen cycling in this isolated environment. In order to determine the diversity and unknown metabolic capabilities of fungi in deep-sea sediments, their genomes need to be fully analyzed. In this study, two Penicillium species were isolated from South Pacific Gyre sediment enrichments during Integrated Ocean Drilling Program Expedition 329. The inner gyre has very limited productivity, organic carbon, and nutrients. RESULTS Here, we present high-quality genomes of two proposed novel Penicillium species using Illumina HiSeq and PacBio sequencing technologies. Single-copy homologues within the genomes were compared to other closely related genomes using OrthoMCL and maximum-likelihood estimation, which showed that these genomes were novel species within the genus Penicillium. We propose to name isolate SPG-F1 as Penicillium pacificasedimenti sp. nov. and SPG-F15 as Penicillium pacificagyrus sp. nov. The resulting genome sizes were 32.6 Mbp and 36.4 Mbp, respectively, and both genomes were greater than 98% complete as determined by the presence of complete single-copy orthologs. The transposable elements for each genome were 4.87% for P. pacificasedimenti and 10.68% for P. pacificagyrus. A total of 12,271 genes were predicted in the P. pacificasedimenti genome and 12,568 genes in P. pacificagyrus. Both isolates contained genes known to be involved in the degradation of recalcitrant carbon, amino acids, and lignin-derived carbon. CONCLUSIONS Our results provide the first constructed genomes of novel Penicillium isolates from deep marine sediments, which will be useful for future studies of marine subsurface fungal diversity and function. Furthermore, these genomes shed light on the potential impact fungi in marine sediments and the subseafloor could have on global carbon and nitrogen biogeochemical cycles and how they may be persisting in the most energy-limited sedimentary biosphere.
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Affiliation(s)
- Morgan S Sobol
- Institute for Biological Interfaces 5, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Baden-Württemberg, Germany
| | - Tatsuhiko Hoshino
- Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Nankoku, Kochi, 783-8502, Japan
| | - Victor Delgado
- Department of Life Sciences, TX A&M University, Corpus Christi, Texas, USA
| | - Taiki Futagami
- Education and Research Center for Fermentation Studies, Faculty of Agriculture, Kagoshima University, Kagoshima, Japan
- United Graduate School of Agricultural Sciences, Kagoshima University, 1-21-24 Korimoto, Kagoshima, 890-0065, Japan
| | - Chihiro Kadooka
- Department of Biotechnology and Life Science, Faculty of Biotechnology and Life Science, Sojo University, Ikeda, Nishiku, Kumamoto, 860-0082, Japan
| | - Fumio Inagaki
- Mantle Drilling Promotion Office, Institute for Marine Earth Exploration and Engineering (MarE3), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokohama, 236- 0001, Japan
- Department of Earth Sciences, Graduate School of Science, Tohoku University, Sendai, 980-8574, Japan
| | - Brandi Kiel Reese
- Dauphin Island Sea Lab, Dauphin Island, Alabama, USA.
- Stokes School of Marine and Environmental Sciences, University of South Alabama, Mobile, AL, USA.
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Lapalu N, Simon A, Demenou B, Paumier D, Guillot MP, Gout L, Suffert F, Valade R. Complete Genome Sequences of Septoria linicola: A Resource for Studying a Damaging Flax Pathogen. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2023; 36:59-63. [PMID: 36537804 DOI: 10.1094/mpmi-09-22-0185-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Fungal genus Septoria causes diseases in a wide range of plants. Here, we report the first genome sequences of two strains of Septoria linicola, the causal agent of the pasmo disease of flax (Linum usitatissimum). The genome of the first strain, SE15195, was fully assembled in 16 chromosomes, while 35 unitigs were obtained for a second strain, SE14017. Structural annotations predicted 13,096 and 13,085 protein-encoding genes and transposable elements content of 19.0 and 18.1% of the genome for SE15195 and SE14017, respectively. The four smaller chromosomes 13 to 16 show genomics features of potential accessory chromosomes. The assembly of these two genomes is a new resource for studying S. linicola and improving management of pasmo. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Nicolas Lapalu
- Université Paris Saclay, INRAE, UR BIOGER, 78850 Thiverval-Grignon, France
| | - Adeline Simon
- Université Paris Saclay, INRAE, UR BIOGER, 78850 Thiverval-Grignon, France
| | | | | | | | - Lilian Gout
- Université Paris Saclay, INRAE, UR BIOGER, 78850 Thiverval-Grignon, France
| | - Frederic Suffert
- Université Paris Saclay, INRAE, UR BIOGER, 78850 Thiverval-Grignon, France
| | - Romain Valade
- ARVALIS Institut du Végétal, 91720 Boigneville, France
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RoyChowdhury M, Sternhagen J, Xin Y, Lou B, Li X, Li C. Evolution of pathogenicity in obligate fungal pathogens and allied genera. PeerJ 2022; 10:e13794. [PMID: 36042858 PMCID: PMC9420410 DOI: 10.7717/peerj.13794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 07/06/2022] [Indexed: 01/17/2023] Open
Abstract
Obligate fungal pathogens (ascomycetes and basidiomycetes) and oomycetes are known to cause diseases in cereal crop plants. They feed on living cells and most of them have learned to bypass the host immune machinery. This paper discusses some of the factors that are associated with pathogenicity drawing examples from ascomycetes, basidiomycetes and oomycetes, with respect to their manifestation in crop plants. The comparisons have revealed a striking similarity in the three groups suggesting convergent pathways that have arisen from three lineages independently leading to an obligate lifestyle. This review has been written with the intent, that new information on adaptation strategies of biotrophs, modifications in pathogenicity strategies and population dynamics will improve current strategies for breeding with stable resistance.
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Affiliation(s)
- Moytri RoyChowdhury
- Infectious Diseases Program, California Department of Public Health, Richmond, California, United States of America
| | - Jake Sternhagen
- Riverside School of Medicine, University of California, Riverside, Riverside, CA, United States of America
| | - Ya Xin
- Hangzhou Academy of Agricultural Sciences, Hangzhou, P.R. China
| | - Binghai Lou
- Guangxi Academy of Specialty Crops, Guilin, Guangxi, P.R. China
| | - Xiaobai Li
- Zhejiang Academy of Agricultural Sciences, Hangzhou, P.R. China
| | - Chunnan Li
- Hangzhou Academy of Agricultural Sciences, Hangzhou, P.R. China
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Comparative Genome Analyses of Plant Rust Pathogen Genomes Reveal a Confluence of Pathogenicity Factors to Quell Host Plant Defense Responses. PLANTS 2022; 11:plants11151962. [PMID: 35956440 PMCID: PMC9370660 DOI: 10.3390/plants11151962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/18/2022] [Accepted: 07/20/2022] [Indexed: 12/05/2022]
Abstract
Switchgrass rust caused by Puccinia novopanici (P. novopanici) has the ability to significantly affect the biomass yield of switchgrass, an important biofuel crop in the United States. A comparative genome analysis of P. novopanici with rust pathogen genomes infecting monocot cereal crops wheat, barley, oats, maize and sorghum revealed the presence of larger structural variations contributing to their genome sizes. A comparative alignment of the rust pathogen genomes resulted in the identification of collinear and syntenic relationships between P. novopanici and P. sorghi; P. graminis tritici 21–0 (Pgt 21) and P. graminis tritici Ug99 (Pgt Ug99) and between Pgt 21 and P. triticina (Pt). Repeat element analysis indicated a strong presence of retro elements among different Puccinia genomes, contributing to the genome size variation between ~1 and 3%. A comparative look at the enriched protein families of Puccinia spp. revealed a predominant role of restriction of telomere capping proteins (RTC), disulfide isomerases, polysaccharide deacetylases, glycoside hydrolases, superoxide dismutases and multi-copper oxidases (MCOs). All the proteomes of Puccinia spp. share in common a repertoire of 75 secretory and 24 effector proteins, including glycoside hydrolases cellobiohydrolases, peptidyl-propyl isomerases, polysaccharide deacetylases and protein disulfide-isomerases, that remain central to their pathogenicity. Comparison of the predicted effector proteins from Puccinia spp. genomes to the validated proteins from the Pathogen–Host Interactions database (PHI-base) resulted in the identification of validated effector proteins PgtSR1 (PGTG_09586) from P. graminis and Mlp124478 from Melampsora laricis across all the rust pathogen genomes.
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Maphosa MN, Steenkamp ET, Kanzi AM, van Wyk S, De Vos L, Santana QC, Duong TA, Wingfield BD. Intra-Species Genomic Variation in the Pine Pathogen Fusarium circinatum. J Fungi (Basel) 2022; 8:jof8070657. [PMID: 35887414 PMCID: PMC9316270 DOI: 10.3390/jof8070657] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 06/02/2022] [Accepted: 06/08/2022] [Indexed: 12/10/2022] Open
Abstract
Fusarium circinatum is an important global pathogen of pine trees. Genome plasticity has been observed in different isolates of the fungus, but no genome comparisons are available. To address this gap, we sequenced and assembled to chromosome level five isolates of F. circinatum. These genomes were analysed together with previously published genomes of F. circinatum isolates, FSP34 and KS17. Multi-sample variant calling identified a total of 461,683 micro variants (SNPs and small indels) and a total of 1828 macro structural variants of which 1717 were copy number variants and 111 were inversions. The variant density was higher on the sub-telomeric regions of chromosomes. Variant annotation revealed that genes involved in transcription, transport, metabolism and transmembrane proteins were overrepresented in gene sets that were affected by high impact variants. A core genome representing genomic elements that were conserved in all the isolates and a non-redundant pangenome representing all genomic elements is presented. Whole genome alignments showed that an average of 93% of the genomic elements were present in all isolates. The results of this study reveal that some genomic elements are not conserved within the isolates and some variants are high impact. The described genome-scale variations will help to inform novel disease management strategies against the pathogen.
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De Miccolis Angelini RM, Landi L, Raguseo C, Pollastro S, Faretra F, Romanazzi G. Tracking of Diversity and Evolution in the Brown Rot Fungi Monilinia fructicola, Monilinia fructigena, and Monilinia laxa. Front Microbiol 2022; 13:854852. [PMID: 35356516 PMCID: PMC8959702 DOI: 10.3389/fmicb.2022.854852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 02/15/2022] [Indexed: 11/13/2022] Open
Abstract
Monilinia species are among the most devastating fungi worldwide as they cause brown rot and blossom blight on fruit trees. To understand the molecular bases of their pathogenic lifestyles, we compared the newly assembled genomes of single strains of Monilinia fructicola, M. fructigena and M. laxa, with those of Botrytis cinerea and Sclerotinia sclerotiorum, as the closest species within Sclerotiniaceae. Phylogenomic analysis of orthologous proteins and syntenic investigation suggest that M. laxa is closer to M. fructigena than M. fructicola, and is closest to the other investigated Sclerotiniaceae species. This indicates that M. laxa was the earliest result of the speciation process. Distinct evolutionary profiles were observed for transposable elements (TEs). M. fructicola and M. laxa showed older bursts of TE insertions, which were affected (mainly in M. fructicola) by repeat-induced point (RIP) mutation gene silencing mechanisms. These suggested frequent occurrence of the sexual process in M. fructicola. More recent TE expansion linked with low RIP action was observed in M. fructigena, with very little in S. sclerotiorum and B. cinerea. The detection of active non-syntenic TEs is indicative of horizontal gene transfer and has resulted in alterations in specific gene functions. Analysis of candidate effectors, biosynthetic gene clusters for secondary metabolites and carbohydrate-active enzymes, indicated that Monilinia genus has multiple virulence mechanisms to infect host plants, including toxins, cell-death elicitor, putative virulence factors and cell-wall-degrading enzymes. Some species-specific pathogenic factors might explain differences in terms of host plant and organ preferences between M. fructigena and the other two Monilinia species.
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Affiliation(s)
| | - Lucia Landi
- Department of Agricultural, Food and Environmental Sciences, Marche Polytechnic University, Ancona, Italy
| | - Celeste Raguseo
- Department of Soil, Plant and Food Sciences, University of Bari Aldo Moro, Bari, Italy
| | - Stefania Pollastro
- Department of Soil, Plant and Food Sciences, University of Bari Aldo Moro, Bari, Italy
| | - Francesco Faretra
- Department of Soil, Plant and Food Sciences, University of Bari Aldo Moro, Bari, Italy
| | - Gianfranco Romanazzi
- Department of Agricultural, Food and Environmental Sciences, Marche Polytechnic University, Ancona, Italy
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DNA Methyltransferases and DNA Damage. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1389:349-361. [DOI: 10.1007/978-3-031-11454-0_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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12
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Porquier A, Tisserant C, Salinas F, Glassl C, Wange L, Enard W, Hauser A, Hahn M, Weiberg A. Retrotransposons as pathogenicity factors of the plant pathogenic fungus Botrytis cinerea. Genome Biol 2021; 22:225. [PMID: 34399815 PMCID: PMC8365987 DOI: 10.1186/s13059-021-02446-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 07/26/2021] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Retrotransposons are genetic elements inducing mutations in all domains of life. Despite their detrimental effect, retrotransposons can become temporarily active during epigenetic reprogramming and cellular stress response, which may accelerate host genome evolution. In fungal pathogens, a positive role has been attributed to retrotransposons when shaping genome architecture and expression of genes encoding pathogenicity factors; thus, retrotransposons are known to influence pathogenicity. RESULTS We uncover a hitherto unknown role of fungal retrotransposons as being pathogenicity factors, themselves. The aggressive fungal plant pathogen, Botrytis cinerea, is known to deliver some long-terminal repeat (LTR) deriving regulatory trans-species small RNAs (BcsRNAs) into plant cells to suppress host gene expression for infection. We find that naturally occurring, less aggressive B. cinerea strains possess considerably lower copy numbers of LTR retrotransposons and had lost retrotransposon BcsRNA production. Using a transgenic proof-of-concept approach, we reconstitute retrotransposon expression in a BcsRNA-lacking B. cinerea strain, which results in enhanced aggressiveness in a retrotransposon and BcsRNA expression-dependent manner. Moreover, retrotransposon expression in B. cinerea leads to suppression of plant defence-related genes during infection. CONCLUSIONS We propose that retrotransposons are pathogenicity factors that manipulate host plant gene expression by encoding trans-species BcsRNAs. Taken together, the novelty that retrotransposons are pathogenicity factors will have a broad impact on studies of host-microbe interactions and pathology.
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Affiliation(s)
| | | | | | - Carla Glassl
- Faculty of Biology, Genetics, LMU Munich, Martinsried, Germany
| | - Lucas Wange
- Faculty of Biology, Anthropology & Human Genomics, LMU Munich, Martinsried, Germany
| | - Wolfgang Enard
- Faculty of Biology, Anthropology & Human Genomics, LMU Munich, Martinsried, Germany
| | - Andreas Hauser
- Gene Center, Laboratory for Functional Genome Analysis, LMU Munich, Martinsried, Germany
| | - Matthias Hahn
- Department of Biology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Arne Weiberg
- Faculty of Biology, Genetics, LMU Munich, Martinsried, Germany.
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Pereira D, Oggenfuss U, McDonald BA, Croll D. Population genomics of transposable element activation in the highly repressive genome of an agricultural pathogen. Microb Genom 2021; 7:000540. [PMID: 34424154 PMCID: PMC8549362 DOI: 10.1099/mgen.0.000540] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 02/03/2021] [Indexed: 12/13/2022] Open
Abstract
The activity of transposable elements (TEs) can be an important driver of genetic diversity with TE-mediated mutations having a wide range of fitness consequences. To avoid deleterious effects of TE activity, some fungi have evolved highly sophisticated genomic defences to reduce TE proliferation across the genome. Repeat-induced point mutation (RIP) is a fungal-specific TE defence mechanism efficiently targeting duplicated sequences. The rapid accumulation of RIPs is expected to deactivate TEs over the course of a few generations. The evolutionary dynamics of TEs at the population level in a species with highly repressive genome defences is poorly understood. Here, we analyse 366 whole-genome sequences of Parastagonospora nodorum, a fungal pathogen of wheat with efficient RIP. A global population genomics analysis revealed high levels of genetic diversity and signs of frequent sexual recombination. Contrary to expectations for a species with RIP, we identified recent TE activity in multiple populations. The TE composition and copy numbers showed little divergence among global populations regardless of the demographic history. Miniature inverted-repeat transposable elements (MITEs) and terminal repeat retrotransposons in miniature (TRIMs) were largely underlying recent intra-species TE expansions. We inferred RIP footprints in individual TE families and found that recently active, high-copy TEs have possibly evaded genomic defences. We find no evidence that recent positive selection acted on TE-mediated mutations rather that purifying selection maintained new TE insertions at low insertion frequencies in populations. Our findings highlight the complex evolutionary equilibria established by the joint action of TE activity, selection and genomic repression.
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Affiliation(s)
- Danilo Pereira
- Plant Pathology, Institute of Integrative Biology, ETH Zürich, Zürich, Switzerland
- Present address: Max Planck Institute for Evolutionary Biology, August-Thienemann-Straße 2, D-24306 Plön, Germany
| | - Ursula Oggenfuss
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Bruce A. McDonald
- Plant Pathology, Institute of Integrative Biology, ETH Zürich, Zürich, Switzerland
| | - Daniel Croll
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
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14
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Lorrain C, Feurtey A, Möller M, Haueisen J, Stukenbrock E. Dynamics of transposable elements in recently diverged fungal pathogens: lineage-specific transposable element content and efficiency of genome defenses. G3-GENES GENOMES GENETICS 2021; 11:6173990. [PMID: 33724368 PMCID: PMC8759822 DOI: 10.1093/g3journal/jkab068] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 02/19/2021] [Indexed: 01/29/2023]
Abstract
Transposable elements (TEs) impact genome plasticity, architecture, and evolution in fungal plant pathogens. The wide range of TE content observed in fungal genomes reflects diverse efficacy of host-genome defense mechanisms that can counter-balance TE expansion and spread. Closely related species can harbor drastically different TE repertoires. The evolution of fungal effectors, which are crucial determinants of pathogenicity, has been linked to the activity of TEs in pathogen genomes. Here, we describe how TEs have shaped genome evolution of the fungal wheat pathogen Zymoseptoria tritici and four closely related species. We compared de novo TE annotations and repeat-induced point mutation signatures in 26 genomes from the Zymoseptoria species-complex. Then, we assessed the relative insertion ages of TEs using a comparative genomics approach. Finally, we explored the impact of TE insertions on genome architecture and plasticity. The 26 genomes of Zymoseptoria species reflect different TE dynamics with a majority of recent insertions. TEs associate with accessory genome compartments, with chromosomal rearrangements, with gene presence/absence variation, and with effectors in all Zymoseptoria species. We find that the extent of RIP-like signatures varies among Z. tritici genomes compared to genomes of the sister species. The detection of a reduction of RIP-like signatures and TE recent insertions in Z. tritici reflects ongoing but still moderate TE mobility.
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Affiliation(s)
- Cécile Lorrain
- Environmental Genomics, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany.,Environmental Genomics, Christian-Albrechts University of Kiel, Kiel 24118, Germany.,Université de Lorraine/INRAE, UMR 1136 Interactions Arbres/Microorganismes, INRAE Centre Grand Est-Nancy, Champenoux 54280, France
| | - Alice Feurtey
- Environmental Genomics, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany.,Environmental Genomics, Christian-Albrechts University of Kiel, Kiel 24118, Germany
| | - Mareike Möller
- Environmental Genomics, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany.,Environmental Genomics, Christian-Albrechts University of Kiel, Kiel 24118, Germany
| | - Janine Haueisen
- Environmental Genomics, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany.,Environmental Genomics, Christian-Albrechts University of Kiel, Kiel 24118, Germany
| | - Eva Stukenbrock
- Environmental Genomics, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany.,Environmental Genomics, Christian-Albrechts University of Kiel, Kiel 24118, Germany
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15
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Hiltunen M, Ament-Velásquez SL, Johannesson H. The Assembled and Annotated Genome of the Fairy-Ring Fungus Marasmius oreades. Genome Biol Evol 2021; 13:evab126. [PMID: 34051082 PMCID: PMC8290104 DOI: 10.1093/gbe/evab126] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/27/2021] [Indexed: 01/07/2023] Open
Abstract
Marasmius oreades is a basidiomycete fungus that grows in so called "fairy rings," which are circular, underground mycelia common in lawns across temperate areas of the world. Fairy rings can be thought of as natural, long-term evolutionary experiments. As each ring has a common origin and expands radially outwards over many years, different sectors will independently accumulate mutations during growth. The genotype can be followed to the next generation, as mushrooms producing the sexual spores are formed seasonally at the edge of the ring. Here, we present new genomic data from 95 single-spore isolates of the species, which we used to construct a genetic linkage map and an updated version of the genome assembly. The 44-Mb assembly was anchored to 11 linkage groups, producing chromosome-length scaffolds. Gene annotation revealed 13,891 genes, 55% of which contained a pfam domain. The repetitive fraction of the genome was 22%, and dominated by retrotransposons and DNA elements of the KDZ and Plavaka groups. The level of assembly contiguity we present is so far rare in mushroom-forming fungi, and we expect studies of genomics, transposons, phylogenetics, and evolution to be facilitated by the data we present here of the iconic fairy-ring mushroom.
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Affiliation(s)
- Markus Hiltunen
- Department of Organismal Biology, Uppsala University, Sweden
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16
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Torres DE, Thomma BPHJ, Seidl MF. Transposable Elements Contribute to Genome Dynamics and Gene Expression Variation in the Fungal Plant Pathogen Verticillium dahliae. Genome Biol Evol 2021; 13:evab135. [PMID: 34100895 PMCID: PMC8290119 DOI: 10.1093/gbe/evab135] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/04/2021] [Indexed: 12/12/2022] Open
Abstract
Transposable elements (TEs) are a major source of genetic and regulatory variation in their host genome and are consequently thought to play important roles in evolution. Many fungal and oomycete plant pathogens have evolved dynamic and TE-rich genomic regions containing genes that are implicated in host colonization and adaptation. TEs embedded in these regions have typically been thought to accelerate the evolution of these genomic compartments, but little is known about their dynamics in strains that harbor them. Here, we used whole-genome sequencing data of 42 strains of the fungal plant pathogen Verticillium dahliae to systematically identify polymorphic TEs that may be implicated in genomic as well as in gene expression variation. We identified 2,523 TE polymorphisms and characterize a subset of 8% of the TEs as polymorphic elements that are evolutionary younger, less methylated, and more highly expressed when compared with the remaining 92% of the total TE complement. As expected, the polyrmorphic TEs are enriched in the adaptive genomic regions. Besides, we observed an association of polymorphic TEs with pathogenicity-related genes that localize nearby and that display high expression levels. Collectively, our analyses demonstrate that TE dynamics in V. dahliae contributes to genomic variation, correlates with expression of pathogenicity-related genes, and potentially impacts the evolution of adaptive genomic regions.
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Affiliation(s)
- David E Torres
- Theoretical Biology and Bioinformatics Group, Department of Biology, Utrecht University, The Netherlands
- Laboratory of Phytopathology, Wageningen University and Research, The Netherlands
| | - Bart P H J Thomma
- Laboratory of Phytopathology, Wageningen University and Research, The Netherlands
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute for Plant Sciences, University of Cologne, Germany
| | - Michael F Seidl
- Theoretical Biology and Bioinformatics Group, Department of Biology, Utrecht University, The Netherlands
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17
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Tobias PA, Schwessinger B, Deng CH, Wu C, Dong C, Sperschneider J, Jones A, Lou Z, Zhang P, Sandhu K, Smith GR, Tibbits J, Chagné D, Park RF. Austropuccinia psidii, causing myrtle rust, has a gigabase-sized genome shaped by transposable elements. G3 (BETHESDA, MD.) 2021; 11:jkaa015. [PMID: 33793741 PMCID: PMC8063080 DOI: 10.1093/g3journal/jkaa015] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 10/26/2020] [Indexed: 02/06/2023]
Abstract
Austropuccinia psidii, originating in South America, is a globally invasive fungal plant pathogen that causes rust disease on Myrtaceae. Several biotypes are recognized, with the most widely distributed pandemic biotype spreading throughout the Asia-Pacific and Oceania regions over the last decade. Austropuccinia psidii has a broad host range with more than 480 myrtaceous species. Since first detected in Australia in 2010, the pathogen has caused the near extinction of at least three species and negatively affected commercial production of several Myrtaceae. To enable molecular and evolutionary studies into A. psidii pathogenicity, we assembled a highly contiguous genome for the pandemic biotype. With an estimated haploid genome size of just over 1 Gb (gigabases), it is the largest assembled fungal genome to date. The genome has undergone massive expansion via distinct transposable element (TE) bursts. Over 90% of the genome is covered by TEs predominantly belonging to the Gypsy superfamily. These TE bursts have likely been followed by deamination events of methylated cytosines to silence the repetitive elements. This in turn led to the depletion of CpG sites in TEs and a very low overall GC content of 33.8%. Compared to other Pucciniales, the intergenic distances are increased by an order of magnitude indicating a general insertion of TEs between genes. Overall, we show how TEs shaped the genome evolution of A. psidii and provide a greatly needed resource for strategic approaches to combat disease spread.
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Affiliation(s)
- Peri A Tobias
- School of Life and Environmental Sciences, University of Sydney, Camperdown, NSW 2006, Australia
- Plant & Food Research Australia, SA 5064, Australia
| | - Benjamin Schwessinger
- Australia Research School of Biology, The Australian National University, Acton, ACT 2601, Australia
| | - Cecilia H Deng
- The New Zealand Institute for Plant and Food Research Limited, Auckland 1142, New Zealand
| | - Chen Wu
- The New Zealand Institute for Plant and Food Research Limited, Auckland 1142, New Zealand
| | - Chongmei Dong
- Plant Breeding Institute, University of Sydney, Narellan, NSW 2567, Australia
| | - Jana Sperschneider
- Biological Data Science Institute, The Australian National University, Canberra, ACT, 2600, Australia
| | - Ashley Jones
- Australia Research School of Biology, The Australian National University, Acton, ACT 2601, Australia
| | - Zhenyan Lou
- Australia Research School of Biology, The Australian National University, Acton, ACT 2601, Australia
| | - Peng Zhang
- Plant Breeding Institute, University of Sydney, Narellan, NSW 2567, Australia
| | - Karanjeet Sandhu
- Plant Breeding Institute, University of Sydney, Narellan, NSW 2567, Australia
| | - Grant R Smith
- The New Zealand Institute for Plant and Food Research Limited, Christchurch 8140, New Zealand
| | - Josquin Tibbits
- Agriculture Victoria Department of Jobs, Precincts and Regions, Bundoora, VIC 3083, Australia
| | - David Chagné
- The New Zealand Institute for Plant & Food Research, Palmerston North 4442, New Zealand
| | - Robert F Park
- Plant Breeding Institute, University of Sydney, Narellan, NSW 2567, Australia
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18
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Wang B, Liang X, Gleason ML, Hsiang T, Zhang R, Sun G. A chromosome-scale assembly of the smallest Dothideomycete genome reveals a unique genome compaction mechanism in filamentous fungi. BMC Genomics 2020; 21:321. [PMID: 32326892 PMCID: PMC7181583 DOI: 10.1186/s12864-020-6732-8] [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: 01/16/2020] [Accepted: 04/14/2020] [Indexed: 11/19/2022] Open
Abstract
Background The wide variation in the size of fungal genomes is well known, but the reasons for this size variation are less certain. Here, we present a chromosome-scale assembly of ectophytic Peltaster fructicola, a surface-dwelling extremophile, based on long-read DNA sequencing technology, to assess possible mechanisms associated with genome compaction. Results At 18.99 million bases (Mb), P. fructicola possesses one of the smallest known genomes sequence among filamentous fungi. The genome is highly compact relative to other fungi, with substantial reductions in repeat content, ribosomal DNA copies, tRNA gene quantity, and intron sizes, as well as intergenic lengths and the size of gene families. Transposons take up just 0.05% of the entire genome, and no full-length transposon was found. We concluded that reduced genome sizes in filamentous fungi such as P. fructicola, Taphrina deformans and Pneumocystis jirovecii occurred through reduction in ribosomal DNA copy number and reduced intron sizes. These dual mechanisms contrast with genome reduction in the yeast fungus Saccharomyces cerevisiae, whose small and compact genome is associated solely with intron loss. Conclusions Our results reveal a unique genomic compaction architecture of filamentous fungi inhabiting plant surfaces, and broaden the understanding of the mechanisms associated with compaction of fungal genomes.
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Affiliation(s)
- Bo Wang
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi Province, China.,MOE Key Laboratory for Intelligent Networks & Network Security, Faculty of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Xiaofei Liang
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi Province, China.
| | - Mark L Gleason
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, 50011, USA
| | - Tom Hsiang
- School of Environmental Sciences, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| | - Rong Zhang
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi Province, China
| | - Guangyu Sun
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi Province, China.
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19
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Min B, Yoon H, Park J, Oh YL, Kong WS, Kim JG, Choi IG. Unusual genome expansion and transcription suppression in ectomycorrhizal Tricholoma matsutake by insertions of transposable elements. PLoS One 2020; 15:e0227923. [PMID: 31978083 PMCID: PMC6980582 DOI: 10.1371/journal.pone.0227923] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 01/02/2020] [Indexed: 12/15/2022] Open
Abstract
Genome sequencing of Tricholoma matsutake revealed its unusually large size as 189.0 Mbp, which is a consequence of extraordinarily high transposable element (TE) content. We identified that 702 genes were surrounded by TEs, and 83.2% of these genes were not transcribed at any developmental stage. This observation indicated that the insertion of TEs alters the transcription of the genes neighboring these TEs. Repeat-induced point mutation, such as C to T hypermutation with a bias over "CpG" dinucleotides, was also recognized in this genome, representing a typical defense mechanism against TEs during evolution. Many transcription factor genes were activated in both the primordia and fruiting body stages, which indicates that many regulatory processes are shared during the developmental stages. Small secreted protein genes (<300 aa) were dominantly transcribed in the hyphae, where symbiotic interactions occur with the hosts. Comparative analysis with 37 Agaricomycetes genomes revealed that IstB-like domains (PF01695) were conserved across taxonomically diverse mycorrhizal genomes, where the T. matsutake genome contained four copies of this domain. Three of the IstB-like genes were overexpressed in the hyphae. Similar to other ectomycorrhizal genomes, the CAZyme gene set was reduced in T. matsutake, including losses in the glycoside hydrolase genes. The T. matsutake genome sequence provides insight into the causes and consequences of genome size inflation.
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Affiliation(s)
- Byoungnam Min
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, Korea
| | - Hyeokjun Yoon
- School of Life Sciences and Biotechnology, College of Natural Sciences, Kyungpook National University, Daegu, Korea
| | - Julius Park
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, Korea
| | - Youn-Lee Oh
- Mushroom Research Division, National Institute of Horticulture and Herbal Science (NIHHS), Rural Development Administration (RDA), Eumseong, Korea
| | - Won-Sik Kong
- Mushroom Research Division, National Institute of Horticulture and Herbal Science (NIHHS), Rural Development Administration (RDA), Eumseong, Korea
- * E-mail: (IC); (WK); (JK)
| | - Jong-Guk Kim
- School of Life Sciences and Biotechnology, College of Natural Sciences, Kyungpook National University, Daegu, Korea
- * E-mail: (IC); (WK); (JK)
| | - In-Geol Choi
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, Korea
- * E-mail: (IC); (WK); (JK)
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20
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21
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van Wyk S, Wingfield BD, De Vos L, van der Merwe NA, Santana QC, Steenkamp ET. Repeat-Induced Point Mutations Drive Divergence between Fusarium circinatum and Its Close Relatives. Pathogens 2019; 8:pathogens8040298. [PMID: 31847413 PMCID: PMC6963459 DOI: 10.3390/pathogens8040298] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 12/06/2019] [Accepted: 12/09/2019] [Indexed: 01/01/2023] Open
Abstract
The Repeat-Induced Point (RIP) mutation pathway is a fungal-specific genome defense mechanism that counteracts the deleterious effects of transposable elements. This pathway permanently mutates its target sequences by introducing cytosine to thymine transitions. We investigated the genome-wide occurrence of RIP in the pitch canker pathogen, Fusarium circinatum, and its close relatives in the Fusarium fujikuroi species complex (FFSC). Our results showed that the examined fungi all exhibited hallmarks of RIP, but that they differed in terms of the extent to which their genomes were affected by this pathway. RIP mutations constituted a large proportion of all the FFSC genomes, including both core and dispensable chromosomes, although the latter were generally more extensively affected by RIP. Large RIP-affected genomic regions were also much more gene sparse than the rest of the genome. Our data further showed that RIP-directed sequence diversification increased the variability between homologous regions of related species, and that RIP-affected regions can interfere with homologous recombination during meiosis, thereby contributing to post-mating segregation distortion. Taken together, these findings suggest that RIP can drive the independent divergence of chromosomes, alter chromosome architecture, and contribute to the divergence among F. circinatum and other members of this economically important group of fungi.
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22
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Mazur AK, Nguyen TS, Gladyshev E. Direct Homologous dsDNA-dsDNA Pairing: How, Where, and Why? J Mol Biol 2019; 432:737-744. [PMID: 31726060 DOI: 10.1016/j.jmb.2019.11.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 10/22/2019] [Accepted: 11/05/2019] [Indexed: 10/25/2022]
Abstract
The ability of homologous chromosomes (or selected chromosomal loci) to pair specifically in the apparent absence of DNA breakage and recombination represents a prominent feature of eukaryotic biology. The mechanism of homology recognition at the basis of such recombination-independent pairing has remained elusive. A number of studies have supported the idea that sequence homology can be sensed between intact DNA double helices in vivo. In particular, recent analyses of the two silencing phenomena in fungi, known as "repeat-induced point mutation" (RIP) and "meiotic silencing by unpaired DNA" (MSUD), have provided genetic evidence for the existence of the direct homologous dsDNA-dsDNA pairing. Both RIP and MSUD likely rely on the same search strategy, by which dsDNA segments are matched as arrays of interspersed base-pair triplets. This process is general and very efficient, yet it proceeds normally without the RecA/Rad51/Dmc1 proteins. Further studies of RIP and MSUD may yield surprising insights into the function of DNA in the cell.
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Affiliation(s)
- Alexey K Mazur
- CNRS, Université de Paris, UPR 9080, Laboratoire de Biochimie Théorique, 13 Rue Pierre et Marie Curie, F-75005 Paris, France; Group Fungal Epigenomics, Department of Mycology, Institut Pasteur, Paris 75015, France; Institut de Biologie Physico-Chimique-Fondation Edmond de Rothschild, PSL Research University, Paris, France
| | - Tinh-Suong Nguyen
- Group Fungal Epigenomics, Department of Mycology, Institut Pasteur, Paris 75015, France
| | - Eugene Gladyshev
- Group Fungal Epigenomics, Department of Mycology, Institut Pasteur, Paris 75015, France.
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23
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Venice F, Ghignone S, Salvioli di Fossalunga A, Amselem J, Novero M, Xianan X, Sędzielewska Toro K, Morin E, Lipzen A, Grigoriev IV, Henrissat B, Martin FM, Bonfante P. At the nexus of three kingdoms: the genome of the mycorrhizal fungus Gigaspora margarita provides insights into plant, endobacterial and fungal interactions. Environ Microbiol 2019; 22:122-141. [PMID: 31621176 DOI: 10.1111/1462-2920.14827] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 09/16/2019] [Accepted: 09/20/2019] [Indexed: 01/04/2023]
Abstract
As members of the plant microbiota, arbuscular mycorrhizal fungi (AMF, Glomeromycotina) symbiotically colonize plant roots. AMF also possess their own microbiota, hosting some uncultivable endobacteria. Ongoing research has revealed the genetics underlying plant responses to colonization by AMF, but the fungal side of the relationship remains in the dark. Here, we sequenced the genome of Gigaspora margarita, a member of the Gigasporaceae in an early diverging group of the Glomeromycotina. In contrast to other AMF, G. margarita may host distinct endobacterial populations and possesses the largest fungal genome so far annotated (773.104 Mbp), with more than 64% transposable elements. Other unique traits of the G. margarita genome include the expansion of genes for inorganic phosphate metabolism, the presence of genes for production of secondary metabolites and a considerable number of potential horizontal gene transfer events. The sequencing of G. margarita genome reveals the importance of its immune system, shedding light on the evolutionary pathways that allowed early diverging fungi to interact with both plants and bacteria.
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Affiliation(s)
- Francesco Venice
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Stefano Ghignone
- Institute for Sustainable Plant Protection-CNR, Turin Unit, Turin, Italy
| | | | | | - Mara Novero
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Xie Xianan
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Key Laboratory of Innovation and Utilization of Forest Plant Germplasm in Guangdong Province, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
| | - Kinga Sędzielewska Toro
- Genetics, Faculty of Biology, Ludwig-Maximilians-University Munich, Planegg-Martinsried, Germany
| | - Emmanuelle Morin
- Institut National de la Recherche Agronomique (INRA), Laboratory of Excellence Advanced Research on the Biology of Tree and Forest Ecosystems (ARBRE), UMR, 1136, Champenoux, France
| | - Anna Lipzen
- Department of Energy Joint Genome Institute, Walnut Creek, CA, USA.,Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Igor V Grigoriev
- Department of Energy Joint Genome Institute, Walnut Creek, CA, USA
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques, CNRS, Aix-Marseille Université, Marseille, 13288, France.,Institut National de la Recherche Agronomique, USC1408 Architecture et Fonction des Macromolécules Biologiques, Marseille, F-13288, France.,Department of Biological Sciences, King Abdulaziz University, Jeddah, 21589, Saudi Arabia
| | - Francis M Martin
- Institut National de la Recherche Agronomique (INRA), Laboratory of Excellence Advanced Research on the Biology of Tree and Forest Ecosystems (ARBRE), UMR, 1136, Champenoux, France
| | - Paola Bonfante
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
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24
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The Parauncinula polyspora Draft Genome Provides Insights into Patterns of Gene Erosion and Genome Expansion in Powdery Mildew Fungi. mBio 2019; 10:mBio.01692-19. [PMID: 31551331 PMCID: PMC6759760 DOI: 10.1128/mbio.01692-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Powdery mildew fungi are widespread and agronomically relevant phytopathogens causing major yield losses. Their genomes have disproportionately large numbers of mobile genetic elements, and they have experienced a significant loss of highly conserved fungal genes. In order to learn more about the evolutionary history of this fungal group, we explored the genome of an Asian oak tree pathogen, Parauncinula polyspora, a species that diverged early during evolution from the remaining powdery mildew fungi. We found that the P. polyspora draft genome is comparatively compact, has a low number of protein-coding genes, and, despite the absence of a dedicated genome defense system, lacks the massive proliferation of repetitive sequences. Based on these findings, we infer an evolutionary trajectory that shaped the genomes of powdery mildew fungi. Due to their comparatively small genome size and short generation time, fungi are exquisite model systems to study eukaryotic genome evolution. Powdery mildew fungi present an exceptional case because of their strict host dependency (termed obligate biotrophy) and the atypical size of their genomes (>100 Mb). This size expansion is largely due to the pervasiveness of transposable elements on 70% of the genome and is associated with the loss of multiple conserved ascomycete genes required for a free-living lifestyle. To date, little is known about the mechanisms that drove these changes, and information on ancestral powdery mildew genomes is lacking. We report genome analysis of the early-diverged and exclusively sexually reproducing powdery mildew fungus Parauncinula polyspora, which we performed on the basis of a natural leaf epiphytic metapopulation sample. In contrast to other sequenced species of this taxonomic group, the assembled P. polyspora draft genome is surprisingly small (<30 Mb), has a higher content of conserved ascomycete genes, and is sparsely equipped with transposons (<10%), despite the conserved absence of a common defense mechanism involved in constraining repetitive elements. We speculate that transposable element spread might have been limited by this pathogen’s unique reproduction strategy and host features and further hypothesize that the loss of conserved ascomycete genes may promote the evolutionary isolation and host niche specialization of powdery mildew fungi. Limitations associated with this evolutionary trajectory might have been in part counteracted by the evolution of plastic, transposon-rich genomes and/or the expansion of gene families encoding secreted virulence proteins.
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Grognet P, Timpano H, Carlier F, Aït-Benkhali J, Berteaux-Lecellier V, Debuchy R, Bidard F, Malagnac F. A RID-like putative cytosine methyltransferase homologue controls sexual development in the fungus Podospora anserina. PLoS Genet 2019; 15:e1008086. [PMID: 31412020 PMCID: PMC6709928 DOI: 10.1371/journal.pgen.1008086] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 08/26/2019] [Accepted: 07/15/2019] [Indexed: 11/18/2022] Open
Abstract
DNA methyltransferases are ubiquitous enzymes conserved in bacteria, plants and opisthokonta. These enzymes, which methylate cytosines, are involved in numerous biological processes, notably development. In mammals and higher plants, methylation patterns established and maintained by the cytosine DNA methyltransferases (DMTs) are essential to zygotic development. In fungi, some members of an extensively conserved fungal-specific DNA methyltransferase class are both mediators of the Repeat Induced Point mutation (RIP) genome defense system and key players of sexual reproduction. Yet, no DNA methyltransferase activity of these purified RID (RIP deficient) proteins could be detected in vitro. These observations led us to explore how RID-like DNA methyltransferase encoding genes would play a role during sexual development of fungi showing very little genomic DNA methylation, if any. To do so, we used the model ascomycete fungus Podospora anserina. We identified the PaRid gene, encoding a RID-like DNA methyltransferase and constructed knocked-out ΔPaRid defective mutants. Crosses involving P. anserina ΔPaRid mutants are sterile. Our results show that, although gametes are readily formed and fertilization occurs in a ΔPaRid background, sexual development is blocked just before the individualization of the dikaryotic cells leading to meiocytes. Complementation of ΔPaRid mutants with ectopic alleles of PaRid, including GFP-tagged, point-mutated and chimeric alleles, demonstrated that the catalytic motif of the putative PaRid methyltransferase is essential to ensure proper sexual development and that the expression of PaRid is spatially and temporally restricted. A transcriptomic analysis performed on mutant crosses revealed an overlap of the PaRid-controlled genetic network with the well-known mating-types gene developmental pathway common to an important group of fungi, the Pezizomycotina.
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Affiliation(s)
- Pierre Grognet
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris‐Saclay, France
| | - Hélène Timpano
- Université Paris-Sud, Institut de Génétique et Microbiologie UMR8621, Orsay, France, CNRS, Institut de Génétique et Microbiologie UMR8621, Orsay, France
| | - Florian Carlier
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris‐Saclay, France
| | - Jinane Aït-Benkhali
- Université Paris-Sud, Institut de Génétique et Microbiologie UMR8621, Orsay, France, CNRS, Institut de Génétique et Microbiologie UMR8621, Orsay, France
| | | | - Robert Debuchy
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris‐Saclay, France
| | - Frédérique Bidard
- Université Paris-Sud, Institut de Génétique et Microbiologie UMR8621, Orsay, France, CNRS, Institut de Génétique et Microbiologie UMR8621, Orsay, France
| | - Fabienne Malagnac
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris‐Saclay, France
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van der Nest MA, Steenkamp ET, Roodt D, Soal NC, Palmer M, Chan WY, Wilken PM, Duong TA, Naidoo K, Santana QC, Trollip C, De Vos L, van Wyk S, McTaggart AR, Wingfield MJ, Wingfield BD. Genomic analysis of the aggressive tree pathogen Ceratocystis albifundus. Fungal Biol 2019; 123:351-363. [PMID: 31053324 DOI: 10.1016/j.funbio.2019.02.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 02/08/2019] [Accepted: 02/11/2019] [Indexed: 12/13/2022]
Abstract
The overall goal of this study was to determine whether the genome of an important plant pathogen in Africa, Ceratocystis albifundus, is structured into subgenomic compartments, and if so, to establish how these compartments are distributed across the genome. For this purpose, the publicly available genome of C. albifundus was complemented with the genome sequences for four additional isolates using the Illumina HiSeq platform. In addition, a reference genome for one of the individuals was assembled using both PacBio and Illumina HiSeq technologies. Our results showed a high degree of synteny between the five genomes, although several regions lacked detectable long-range synteny. These regions were associated with the presence of accessory genes, lower genetic similarity, variation in read-map depth, as well as transposable elements and genes associated with host-pathogen interactions (e.g. effectors and CAZymes). Such patterns are regarded as hallmarks of accelerated evolution, particularly of accessory subgenomic compartments in fungal pathogens. Our findings thus showed that the genome of C. albifundus is made-up of core and accessory subgenomic compartments, which is an important step towards characterizing its pangenome. This study also highlights the value of comparative genomics for understanding mechanisms that may underly and influence the biology and evolution of pathogens.
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Affiliation(s)
- Magriet A van der Nest
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa.
| | - Emma T Steenkamp
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Danielle Roodt
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Nicole C Soal
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Marike Palmer
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Wai-Yin Chan
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - P Markus Wilken
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Tuan A Duong
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Kershney Naidoo
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Quentin C Santana
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Conrad Trollip
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Lieschen De Vos
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Stephanie van Wyk
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Alistair R McTaggart
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Michael J Wingfield
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Brenda D Wingfield
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
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Botcinic acid biosynthesis in Botrytis cinerea relies on a subtelomeric gene cluster surrounded by relics of transposons and is regulated by the Zn2Cys6 transcription factor BcBoa13. Curr Genet 2019; 65:965-980. [DOI: 10.1007/s00294-019-00952-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 02/26/2019] [Accepted: 03/02/2019] [Indexed: 01/11/2023]
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Amselem J, Cornut G, Choisne N, Alaux M, Alfama-Depauw F, Jamilloux V, Maumus F, Letellier T, Luyten I, Pommier C, Adam-Blondon AF, Quesneville H. RepetDB: a unified resource for transposable element references. Mob DNA 2019; 10:6. [PMID: 30719103 PMCID: PMC6350395 DOI: 10.1186/s13100-019-0150-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 01/24/2019] [Indexed: 11/11/2022] Open
Abstract
Background Thanks to their ability to move around and replicate within genomes, transposable elements (TEs) are perhaps the most important contributors to genome plasticity and evolution. Their detection and annotation are considered essential in any genome sequencing project. The number of fully sequenced genomes is rapidly increasing with improvements in high-throughput sequencing technologies. A fully automated de novo annotation process for TEs is therefore required to cope with the deluge of sequence data. However, all automated procedures are error-prone, and an automated procedure for TE identification and classification would be no exception. It is therefore crucial to provide not only the TE reference sequences, but also evidence justifying their classification, at the scale of the whole genome. A few TE databases already exist, but none provides evidence to justify TE classification. Moreover, biological information about the sequences remains globally poor. Results We present here the RepetDB database developed in the framework of GnpIS, a genetic and genomic information system. RepetDB is designed to store and retrieve detected, classified and annotated TEs in a standardized manner. RepetDB is an implementation with extensions of InterMine, an open-source data warehouse framework used here to store, search, browse, analyze and compare all the data recorded for each TE reference sequence. InterMine can display diverse information for each sequence and allows simple to very complex queries. Finally, TE data are displayed via a worldwide data discovery portal. RepetDB is accessible at urgi.versailles.inra.fr/repetdb. Conclusions RepetDB is designed to be a TE knowledge base populated with full de novo TE annotations of complete (or near-complete) genome sequences. Indeed, the description and classification of TEs facilitates the exploration of specific TE families, superfamilies or orders across a large range of species. It also makes possible cross-species searches and comparisons of TE family content between genomes.
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Affiliation(s)
- Joëlle Amselem
- URGI, INRA, Université Paris-Saclay, 78026 Versailles, France
| | | | | | - Michael Alaux
- URGI, INRA, Université Paris-Saclay, 78026 Versailles, France
| | | | | | - Florian Maumus
- URGI, INRA, Université Paris-Saclay, 78026 Versailles, France
| | | | - Isabelle Luyten
- URGI, INRA, Université Paris-Saclay, 78026 Versailles, France
| | - Cyril Pommier
- URGI, INRA, Université Paris-Saclay, 78026 Versailles, France
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Van de Wouw AP, Elliott CE, Popa KM, Idnurm A. Analysis of Repeat Induced Point (RIP) Mutations in Leptosphaeria maculans Indicates Variability in the RIP Process Between Fungal Species. Genetics 2019; 211:89-104. [PMID: 30389803 PMCID: PMC6325690 DOI: 10.1534/genetics.118.301712] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 10/24/2018] [Indexed: 01/01/2023] Open
Abstract
Gene duplication contributes to evolutionary potential, yet many duplications in a genome arise from the activity of "selfish" genetic elements such as transposable elements. Fungi have a number of mechanisms by which they limit the expansion of transposons, including Repeat Induced Point mutation (RIP). RIP has been best characterized in the Sordariomycete Neurospora crassa, wherein duplicated DNA regions are recognized after cell fusion, but before nuclear fusion during the sexual cycle, and then mutated. While "signatures" of RIP appear in the genome sequences of many fungi, the species most distant from N. crassa in which the process has been experimentally demonstrated to occur is the Dothideomycete Leptosphaeria maculans In the current study, we show that similar to N. crassa, nonlinked duplications can trigger RIP; however, the frequency of the generated RIP mutations is extremely low in L maculans (< 0.1%) and requires a large duplication to initiate RIP, and that multiple premeiotic mitoses are involved in the RIP process. However, a single sexual cycle leads to the generation of progeny with unique haplotypes, despite progeny pairs being generated from mitosis. We hypothesize that these different haplotypes may be the result of the deamination process occurring post karyogamy, leading to unique mutations within each of the progeny pairs. These findings indicate that the RIP process, while common to many fungi, differs between fungi and that this impacts on the fate of duplicated DNA.
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Affiliation(s)
- Angela P Van de Wouw
- School of BioSciences, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Candace E Elliott
- School of BioSciences, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Kerryn M Popa
- School of BioSciences, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Alexander Idnurm
- School of BioSciences, The University of Melbourne, Parkville, Victoria 3010, Australia
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30
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Zeng Z, Wu J, Kovalchuk A, Raffaello T, Wen Z, Liu M, Asiegbu FO. Genome-wide DNA methylation and transcriptomic profiles in the lifestyle strategies and asexual development of the forest fungal pathogen Heterobasidion parviporum. Epigenetics 2019; 14:16-40. [PMID: 30633603 PMCID: PMC6380393 DOI: 10.1080/15592294.2018.1564426] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 12/03/2018] [Accepted: 12/20/2018] [Indexed: 12/18/2022] Open
Abstract
Heterobasidion parviporum is the most devastating fungal pathogen of conifer forests in Northern Europe. The fungus has dual life strategies, necrotrophy on living trees and saprotrophy on dead woods. DNA cytosine methylation is an important epigenetic modification in eukaryotic organisms. Our presumption is that the lifestyle transition and asexual development in H. parviporum could be driven by epigenetic effects. Involvements of DNA methylation in the regulation of aforementioned processes have never been studied thus far. RNA-seq identified lists of highly induced genes enriched in carbohydrate-active enzymes during necrotrophic interaction with host trees and saprotrophic sawdust growth. It also highlighted signaling- and transcription factor-related genes potentially associated with the transition of saprotrophic to necrotrophic lifestyle and groups of primary cellular activities throughout asexual development. Whole-genome bisulfite sequencing revealed that DNA methylation displayed pronounced preference in CpG dinucleotide context across the genome and mostly targeted transposable element (TE)-rich regions. TE methylation level demonstrated a strong negative correlation with TE expression, reinforcing the protective function of DNA methylation in fungal genome stability. Small groups of genes putatively subject to methylation transcriptional regulation in response to saprotrophic and necrotrophic growth in comparison with free-living mycelia were also explored. Our study reported on the first methylome map of a forest pathogen. Analysis of transcriptome and methylome variations associated with asexual development and different lifestyle strategies provided further understanding of basic biological processes in H. parviporum. More importantly, our work raised additional potential roles of DNA methylation in fungi apart from controlling the proliferation of TEs.
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Affiliation(s)
- Zhen Zeng
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Jiayao Wu
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Andriy Kovalchuk
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Tommaso Raffaello
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Zilan Wen
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Mengxia Liu
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Fred O. Asiegbu
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
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31
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Aylward J, Wingfield BD, Dreyer LL, Roets F, Wingfield MJ, Steenkamp ET. Genomic overview of closely related fungi with different Protea host ranges. Fungal Biol 2018; 122:1201-1214. [PMID: 30449358 DOI: 10.1016/j.funbio.2018.10.001] [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: 07/17/2018] [Revised: 09/06/2018] [Accepted: 10/04/2018] [Indexed: 11/28/2022]
Abstract
Genome comparisons of species with distinctive ecological traits can elucidate genetic divergence that influenced their differentiation. The interaction of a microorganism with its biotic environment is largely regulated by secreted compounds, and these can be predicted from genome sequences. In this study, we considered Knoxdaviesia capensis and Knoxdaviesia proteae, two closely related saprotrophic fungi found exclusively in Protea plants. We investigated their genome structure to compare their potential inter-specific interactions based on gene content. Their genomes displayed macrosynteny and were approximately 10 % repetitive. Both species had fewer secreted proteins than pathogens and other saprotrophs, reflecting their specialized habitat. The bulk of the predicted species-specific and secreted proteins coded for carbohydrate metabolism, with a slightly higher number of unique carbohydrate-degrading proteins in the broad host-range K. capensis. These fungi have few secondary metabolite gene clusters, suggesting minimal competition with other microbes and symbiosis with antibiotic-producing bacteria common in this niche. Secreted proteins associated with detoxification and iron sequestration likely enable these Knoxdaviesia species to tolerate antifungal compounds and compete for resources, facilitating their unusual dominance. This study confirms the genetic cohesion between Protea-associated Knoxdaviesia species and reveals aspects of their ecology that have likely evolved in response to their specialist niche.
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Affiliation(s)
- Janneke Aylward
- Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa; Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa.
| | - Brenda D Wingfield
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa
| | - Léanne L Dreyer
- Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| | - Francois Roets
- Department of Conservation Ecology and Entomology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| | - Michael J Wingfield
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa
| | - Emma T Steenkamp
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa
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Murat C, Payen T, Noel B, Kuo A, Morin E, Chen J, Kohler A, Krizsán K, Balestrini R, Da Silva C, Montanini B, Hainaut M, Levati E, Barry KW, Belfiori B, Cichocki N, Clum A, Dockter RB, Fauchery L, Guy J, Iotti M, Le Tacon F, Lindquist EA, Lipzen A, Malagnac F, Mello A, Molinier V, Miyauchi S, Poulain J, Riccioni C, Rubini A, Sitrit Y, Splivallo R, Traeger S, Wang M, Žifčáková L, Wipf D, Zambonelli A, Paolocci F, Nowrousian M, Ottonello S, Baldrian P, Spatafora JW, Henrissat B, Nagy LG, Aury JM, Wincker P, Grigoriev IV, Bonfante P, Martin FM. Pezizomycetes genomes reveal the molecular basis of ectomycorrhizal truffle lifestyle. Nat Ecol Evol 2018; 2:1956-1965. [DOI: 10.1038/s41559-018-0710-4] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 10/04/2018] [Indexed: 11/09/2022]
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Rao S, Sharda S, Oddi V, Nandineni MR. The Landscape of Repetitive Elements in the Refined Genome of Chilli Anthracnose Fungus Colletotrichum truncatum. Front Microbiol 2018; 9:2367. [PMID: 30337918 PMCID: PMC6180176 DOI: 10.3389/fmicb.2018.02367] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 09/14/2018] [Indexed: 12/15/2022] Open
Abstract
The ascomycete fungus Colletotrichum truncatum is a major phytopathogen with a broad host range which causes anthracnose disease of chilli. The genome sequencing of this fungus led to the discovery of functional categories of genes that may play important roles in fungal pathogenicity. However, the presence of gaps in C. truncatum draft assembly prevented the accurate prediction of repetitive elements, which are the key players to determine the genome architecture and drive evolution and host adaptation. We re-sequenced its genome using single-molecule real-time (SMRT) sequencing technology to obtain a refined assembly with lesser and smaller gaps and ambiguities. This enabled us to study its genome architecture by characterising the repetitive sequences like transposable elements (TEs) and simple sequence repeats (SSRs), which constituted 4.9 and 0.38% of the assembled genome, respectively. The comparative analysis among different Colletotrichum species revealed the extensive repeat rich regions, dominated by Gypsy superfamily of long terminal repeats (LTRs), and the differential composition of SSRs in their genomes. Our study revealed a recent burst of LTR amplification in C. truncatum, C. higginsianum, and C. scovillei. TEs in C. truncatum were significantly associated with secretome, effectors and genes in secondary metabolism clusters. Some of the TE families in C. truncatum showed cytosine to thymine transitions indicative of repeat-induced point mutation (RIP). C. orbiculare and C. graminicola showed strong signatures of RIP across their genomes and "two-speed" genomes with extensive AT-rich and gene-sparse regions. Comparative genomic analyses of Colletotrichum species provided an insight into the species-specific SSR profiles. The SSRs in the coding and non-coding regions of the genome revealed the composition of trinucleotide repeat motifs in exons with potential to alter the translated protein structure through amino acid repeats. This is the first genome-wide study of TEs and SSRs in C. truncatum and their comparative analysis with six other Colletotrichum species, which would serve as a useful resource for future research to get insights into the potential role of TEs in genome expansion and evolution of Colletotrichum fungi and for development of SSR-based molecular markers for population genomic studies.
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Affiliation(s)
- Soumya Rao
- Laboratory of Genomics and Profiling Applications, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India
- Graduate Studies, Manipal Academy of Higher Education, Manipal, India
| | - Saphy Sharda
- Laboratory of Genomics and Profiling Applications, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India
| | - Vineesha Oddi
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India
| | - Madhusudan R. Nandineni
- Laboratory of Genomics and Profiling Applications, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India
- Laboratory of DNA Fingerprinting Services, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India
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Kusch S, Frantzeskakis L, Thieron H, Panstruga R. Small RNAs from cereal powdery mildew pathogens may target host plant genes. Fungal Biol 2018; 122:1050-1063. [PMID: 30342621 DOI: 10.1016/j.funbio.2018.08.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 08/25/2018] [Accepted: 08/28/2018] [Indexed: 12/24/2022]
Abstract
Small RNAs (sRNAs) play a key role in eukaryotic gene regulation, for example by gene silencing via RNA interference (RNAi). The biogenesis of sRNAs depends on proteins that are generally conserved in all eukaryotic lineages, yet some species that lack part or all the components of the mechanism exist. Here we explored the presence of the RNAi machinery and its expression as well as the occurrence of sRNA candidates and their putative endogenous as well as host targets in phytopathogenic powdery mildew fungi. We focused on the species Blumeria graminis, which occurs in various specialized forms (formae speciales) that each have a strictly limited host range. B. graminis f. sp. hordei and B. graminis f. sp. tritici, colonizing barley and wheat, respectively, have genomes that are characterized by extensive gene loss. Nonetheless, we find that the RNAi machinery appears to be largely complete and expressed during infection. sRNA sequencing data enabled the identification of putative sRNAs in both pathogens. While a considerable part of the sRNA candidates have predicted target sites in endogenous genes and transposable elements, a small proportion appears to have targets in planta, suggesting potential cross-kingdom RNA transfer between powdery mildew fungi and their respective plant hosts.
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Affiliation(s)
- Stefan Kusch
- Unit of Plant Molecular Cell Biology, Institute for Biology I, RWTH Aachen University, Worringerweg 1, D-52056 Aachen, Germany.
| | - Lamprinos Frantzeskakis
- Unit of Plant Molecular Cell Biology, Institute for Biology I, RWTH Aachen University, Worringerweg 1, D-52056 Aachen, Germany.
| | - Hannah Thieron
- Unit of Plant Molecular Cell Biology, Institute for Biology I, RWTH Aachen University, Worringerweg 1, D-52056 Aachen, Germany.
| | - Ralph Panstruga
- Unit of Plant Molecular Cell Biology, Institute for Biology I, RWTH Aachen University, Worringerweg 1, D-52056 Aachen, Germany.
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35
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Izquierdo-Bueno I, González-Rodríguez VE, Simon A, Dalmais B, Pradier JM, Le Pêcheur P, Mercier A, Walker AS, Garrido C, Collado IG, Viaud M. Biosynthesis of abscisic acid in fungi: identification of a sesquiterpene cyclase as the key enzyme in Botrytis cinerea. Environ Microbiol 2018; 20:2469-2482. [PMID: 29708647 DOI: 10.1111/1462-2920.14258] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 04/24/2018] [Accepted: 04/25/2018] [Indexed: 12/25/2022]
Abstract
While abscisic acid (ABA) is known as a hormone produced by plants through the carotenoid pathway, a small number of phytopathogenic fungi are also able to produce this sesquiterpene but they use a distinct pathway that starts with the cyclization of farnesyl diphosphate (FPP) into 2Z,4E-α-ionylideneethane which is then subjected to several oxidation steps. To identify the sesquiterpene cyclase (STC) responsible for the biosynthesis of ABA in fungi, we conducted a genomic approach in Botrytis cinerea. The genome of the ABA-overproducing strain ATCC58025 was fully sequenced and five STC-coding genes were identified. Among them, Bcstc5 exhibits an expression profile concomitant with ABA production. Gene inactivation, complementation and chemical analysis demonstrated that BcStc5/BcAba5 is the key enzyme responsible for the key step of ABA biosynthesis in fungi. Unlike what is observed for most of the fungal secondary metabolism genes, the key enzyme-coding gene Bcstc5/Bcaba5 is not clustered with the other biosynthetic genes, i.e., Bcaba1 to Bcaba4 that are responsible for the oxidative transformation of 2Z,4E-α-ionylideneethane. Finally, our study revealed that the presence of the Bcaba genes among Botrytis species is rare and that the majority of them do not possess the ability to produce ABA.
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Affiliation(s)
- Inmaculada Izquierdo-Bueno
- Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Cádiz, Cádiz, 11510 Puerto Real, Spain
| | - Victoria E González-Rodríguez
- Departamento de Biomedicina, Biotecnología y Salud Pública, Laboratorio de Microbiología, Facultad de Ciencias de Mar y Ambientales, Universidad de Cádiz, Puerto Real, Cádiz 11510, Spain
| | - Adeline Simon
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, 78850 Thiverval-Grignon, France
| | - Bérengère Dalmais
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, 78850 Thiverval-Grignon, France
| | - Jean-Marc Pradier
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, 78850 Thiverval-Grignon, France
| | - Pascal Le Pêcheur
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, 78850 Thiverval-Grignon, France
| | - Alex Mercier
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, 78850 Thiverval-Grignon, France.,Université Paris-Sud, 91405 Orsay, France
| | - Anne-Sophie Walker
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, 78850 Thiverval-Grignon, France
| | - Carlos Garrido
- Departamento de Biomedicina, Biotecnología y Salud Pública, Laboratorio de Microbiología, Facultad de Ciencias de Mar y Ambientales, Universidad de Cádiz, Puerto Real, Cádiz 11510, Spain
| | - Isidro González Collado
- Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Cádiz, Cádiz, 11510 Puerto Real, Spain
| | - Muriel Viaud
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, 78850 Thiverval-Grignon, France
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Dal Molin A, Minio A, Griggio F, Delledonne M, Infantino A, Aragona M. The genome assembly of the fungal pathogen Pyrenochaeta lycopersici from Single-Molecule Real-Time sequencing sheds new light on its biological complexity. PLoS One 2018; 13:e0200217. [PMID: 29979772 PMCID: PMC6034849 DOI: 10.1371/journal.pone.0200217] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 06/21/2018] [Indexed: 12/19/2022] Open
Abstract
The first draft genome sequencing of the non-model fungal pathogen Pyrenochaeta lycopersici showed an expansion of gene families associated with heterokaryon incompatibility and lacking of mating-type genes, providing insights into the genetic basis of this “imperfect” fungus which lost the ability to produce the sexual stage. However, due to the Illumina short-read technology, the draft genome was too fragmented to allow a comprehensive characterization of the genome, especially of the repetitive sequence fraction. In this work, the sequencing of another P. lycopersici isolate using long-read Single Molecule Real-Time sequencing technology was performed with the aim of obtaining a gapless genome. Indeed, a gapless genome assembly of 62.7 Mb was obtained, with a fraction of repetitive sequences representing 30% of the total bases. The gene content of the two P. lycopersici isolates was very similar, and the large difference in genome size (about 8 Mb) might be attributable to the high fraction of repetitive sequences detected for the new sequenced isolate. The role of repetitive elements, including transposable elements, in modulating virulence effectors is well established in fungal plant pathogens. Moreover, transposable elements are of fundamental importance in creating and re-modelling genes, especially in imperfect fungi. Their abundance in P. lycopersici, together with the large expansion of heterokaryon incompatibility genes in both sequenced isolates, suggest the presence of possible mechanisms alternative to gene re-assorting mediated by sexual recombination. A quite large fraction (~9%) of repetitive elements in P. lycopersici, has no homology with known classes, strengthening this hypothesis. The availability of a gapless genome of P. lycopersici allowed the in-depth analysis of its genome content, by annotating functional genes and TEs. This goal will be an important resource for shedding light on the evolution of the reproductive and pathogenic behaviour of this soilborne pathogen and the onset of a possible speciation within this species.
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Affiliation(s)
| | - Andrea Minio
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Verona, Italy
| | - Francesca Griggio
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Verona, Italy
| | - Massimo Delledonne
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Verona, Italy
| | - Alessandro Infantino
- Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria, Research Centre for Plant Protection and Certification, Rome, Italy
| | - Maria Aragona
- Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria, Research Centre for Plant Protection and Certification, Rome, Italy
- * E-mail:
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37
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Sabelleck B, Panstruga R. Novel jack-in-the-box effector of the barley powdery mildew pathogen? JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:3511-3514. [PMID: 29947808 PMCID: PMC6022647 DOI: 10.1093/jxb/ery192] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
This article comments on: Nottensteiner M, Zechmann B, McCollum C, Hückelhoven R. 2018. A barley powdery mildew fungus non-autonomous retrotransposon encodes a peptide that supports penetration success on barley. Journal of Experimental Botany 69, 3745–3758.
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Affiliation(s)
- Björn Sabelleck
- RWTH Aachen University, Institute for Biology I, Unit of Plant Molecular Cell Biology, Worringerweg, Aachen, Germany
| | - Ralph Panstruga
- RWTH Aachen University, Institute for Biology I, Unit of Plant Molecular Cell Biology, Worringerweg, Aachen, Germany
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38
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Zeng Z, Sun H, Vainio EJ, Raffaello T, Kovalchuk A, Morin E, Duplessis S, Asiegbu FO. Intraspecific comparative genomics of isolates of the Norway spruce pathogen (Heterobasidion parviporum) and identification of its potential virulence factors. BMC Genomics 2018; 19:220. [PMID: 29580224 PMCID: PMC5870257 DOI: 10.1186/s12864-018-4610-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 03/20/2018] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Heterobasidion parviporum is an economically most important fungal forest pathogen in northern Europe, causing root and butt rot disease of Norway spruce (Picea abies (L.) Karst.). The mechanisms underlying the pathogenesis and virulence of this species remain elusive. No reference genome to facilitate functional analysis is available for this species. RESULTS To better understand the virulence factor at both phenotypic and genomic level, we characterized 15 H. parviporum isolates originating from different locations across Finland for virulence, vegetative growth, sporulation and saprotrophic wood decay. Wood decay capability and latitude of fungal origins exerted interactive effects on their virulence and appeared important for H. parviporum virulence. We sequenced the most virulent isolate, the first full genome sequences of H. parviporum as a reference genome, and re-sequenced the remaining 14 H. parviporum isolates. Genome-wide alignments and intrinsic polymorphism analysis showed that these isolates exhibited overall high genomic similarity with an average of at least 96% nucleotide identity when compared to the reference, yet had remarkable intra-specific level of polymorphism with a bias for CpG to TpG mutations. Reads mapping coverage analysis enabled the classification of all predicted genes into five groups and uncovered two genomic regions exclusively present in the reference with putative contribution to its higher virulence. Genes enriched for copy number variations (deletions and duplications) and nucleotide polymorphism were involved in oxidation-reduction processes and encoding domains relevant to transcription factors. Some secreted protein coding genes based on the genome-wide selection pressure, or the presence of variants were proposed as potential virulence candidates. CONCLUSION Our study reported on the first reference genome sequence for this Norway spruce pathogen (H. parviporum). Comparative genomics analysis gave insight into the overall genomic variation among this fungal species and also facilitated the identification of several secreted protein coding genes as putative virulence factors for the further functional analysis. We also analyzed and identified phenotypic traits potentially linked to its virulence.
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Affiliation(s)
- Zhen Zeng
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Hui Sun
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
- Collaborative Innovation Center of Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Eeva J. Vainio
- Natural Resources Institute Finland (Luke), Helsinki, Finland
| | - Tommaso Raffaello
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Andriy Kovalchuk
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Emmanuelle Morin
- INRA UMR 1136 Interactions Arbres Micro-organismes, INRA Centre Grand Est Nancy, Champenoux, France
| | - Sébastien Duplessis
- INRA UMR 1136 Interactions Arbres Micro-organismes, INRA Centre Grand Est Nancy, Champenoux, France
- UMR 1136 Interactions Arbres/Microorganismes, Faculté des Sciences et Technologies, Université de Lorraine, Vandoeuvre-lès-Nancy, France
| | - Fred O. Asiegbu
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
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Brar GS, Ali S, Qutob D, Ambrose S, Lou K, Maclachlan R, Pozniak CJ, Fu YB, Sharpe AG, Kutcher HR. Genome re-sequencing and simple sequence repeat markers reveal the existence of divergent lineages in the Canadian Puccinia striiformis
f. sp. tritici
population with extensive DNA methylation. Environ Microbiol 2018; 20:1498-1515. [DOI: 10.1111/1462-2920.14067] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 01/30/2018] [Accepted: 02/02/2018] [Indexed: 12/25/2022]
Affiliation(s)
- Gurcharn S. Brar
- Crop Development Centre/Department of Plant Sciences, College of Agriculture and Bioresources; University of Saskatchewan, 51 Campus Dr; Saskatoon SK S7N 5A8 Canada
| | - Sajid Ali
- Institute of Biotechnology and Genetic Engineering; University of Agriculture; Peshawar Pakistan
| | - Dinah Qutob
- Aquatic and Crop Resource Development; National Research Council of Canada, 110 Gymnasium Place; Saskatoon SK S7N 0W9 Canada
| | - Stephen Ambrose
- Aquatic and Crop Resource Development; National Research Council of Canada, 110 Gymnasium Place; Saskatoon SK S7N 0W9 Canada
| | - Kun Lou
- Crop Development Centre/Department of Plant Sciences, College of Agriculture and Bioresources; University of Saskatchewan, 51 Campus Dr; Saskatoon SK S7N 5A8 Canada
| | - Ron Maclachlan
- Crop Development Centre/Department of Plant Sciences, College of Agriculture and Bioresources; University of Saskatchewan, 51 Campus Dr; Saskatoon SK S7N 5A8 Canada
| | - Curtis J. Pozniak
- Crop Development Centre/Department of Plant Sciences, College of Agriculture and Bioresources; University of Saskatchewan, 51 Campus Dr; Saskatoon SK S7N 5A8 Canada
| | - Yong-Bi Fu
- Plant Gene Resources of Canada, Agriculture & Agri-Food Canada- Saskatoon Research and Development Centre, 107 Science Place; Saskatoon SK S7N 0X2 Canada
| | - Andrew G. Sharpe
- Global Institute for Food Security, University of Saskatchewan, 110 Gymnasium Place; Saskatoon SK S7N 0W9 Canada
| | - Hadley R. Kutcher
- Crop Development Centre/Department of Plant Sciences, College of Agriculture and Bioresources; University of Saskatchewan, 51 Campus Dr; Saskatoon SK S7N 5A8 Canada
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Abstract
Transposable elements have colonized the genomes of nearly all organisms, including fungi. Although transposable elements may sometimes provide beneficial functions to their hosts their overall impact is considered deleterious. As a result, the activity of transposable elements needs to be counterbalanced by the host genome defenses. In fungi, the primary genome defense mechanisms include repeat-induced point mutation (RIP) and methylation induced premeiotically, meiotic silencing by unpaired DNA, sex-induced silencing, cosuppression (also known as somatic quelling), and cotranscriptional RNA surveillance. Recent studies of the filamentous fungus Neurospora crassa have shown that the process of repeat recognition for RIP apparently involves interactions between coaligned double-stranded segments of chromosomal DNA. These studies have also shown that RIP can be mediated by the conserved pathway that establishes transcriptional (heterochromatic) silencing of repetitive DNA. In light of these new findings, RIP emerges as a specialized case of the general phenomenon of heterochromatic silencing of repetitive DNA.
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So KK, Ko YH, Chun J, Bal J, Jeon J, Kim JM, Choi J, Lee YH, Huh JH, Kim DH. Global DNA Methylation in the Chestnut Blight Fungus Cryphonectria parasitica and Genome-Wide Changes in DNA Methylation Accompanied with Sectorization. FRONTIERS IN PLANT SCIENCE 2018; 9:103. [PMID: 29456549 PMCID: PMC5801561 DOI: 10.3389/fpls.2018.00103] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 01/18/2018] [Indexed: 06/08/2023]
Abstract
Mutation in CpBck1, an ortholog of the cell wall integrity mitogen-activated protein kinase kinase kinase (MAPKKK) of Saccharomyces cerevisiae, in the chestnut blight fungus Cryphonectria parasitica resulted in a sporadic sectorization as culture proceeded. The progeny from the sectored area maintained the characteristics of the sector, showing a massive morphogenetic change, including robust mycelial growth without differentiation. Epigenetic changes were investigated as the genetic mechanism underlying this sectorization. Quantification of DNA methylation and whole-genome bisulfite sequencing revealed genome-wide DNA methylation of the wild-type at each nucleotide level and changes in DNA methylation of the sectored progeny. Compared to the wild-type, the sectored progeny exhibited marked genome-wide DNA hypomethylation but increased methylation sites. Expression analysis of two DNA methyltransferases, including two representative types of DNA methyltransferase (DNMTase), demonstrated that both were significantly down-regulated in the sectored progeny. However, functional analysis using mutant phenotypes of corresponding DNMTases demonstrated that a mutant of CpDmt1, an ortholog of RID of Neurospora crassa, resulted in the sectored phenotype but the CpDmt2 mutant did not, suggesting that the genetic basis of fungal sectorization is more complex. The present study revealed that a mutation in a signaling pathway component resulted in sectorization accompanied with changes in genome-wide DNA methylation, which suggests that this signal transduction pathway is important for epigenetic control of sectorization via regulation of genes involved in DNA methylation.
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Affiliation(s)
- Kum-Kang So
- Institute for Molecular Biology and Genetics, Center for Fungal Pathogenesis, Chonbuk National University, Jeonju, South Korea
| | - Yo-Han Ko
- Institute for Molecular Biology and Genetics, Center for Fungal Pathogenesis, Chonbuk National University, Jeonju, South Korea
| | - Jeesun Chun
- Institute for Molecular Biology and Genetics, Center for Fungal Pathogenesis, Chonbuk National University, Jeonju, South Korea
| | - Jyotiranjan Bal
- Institute for Molecular Biology and Genetics, Center for Fungal Pathogenesis, Chonbuk National University, Jeonju, South Korea
| | - Junhyun Jeon
- Department of Biotechnology, College of Life and Applied Sciences, Yeungnam University, Gyeongsan, South Korea
| | - Jung-Mi Kim
- Department of Bio-Environmental Chemistry, Wonkwang University, Iksan, South Korea
| | - Jaeyoung Choi
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Yong-Hwan Lee
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Jin Hoe Huh
- Department of Plant Science, Seoul National University, Seoul, South Korea
| | - Dae-Hyuk Kim
- Institute for Molecular Biology and Genetics, Center for Fungal Pathogenesis, Chonbuk National University, Jeonju, South Korea
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42
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Tang C, Xu Q, Zhao M, Wang X, Kang Z. Understanding the lifestyles and pathogenicity mechanisms of obligate biotrophic fungi in wheat: The emerging genomics era. ACTA ACUST UNITED AC 2018. [DOI: 10.1016/j.cj.2017.11.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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43
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Molano EPL, Cabrera OG, Jose J, do Nascimento LC, Carazzolle MF, Teixeira PJPL, Alvarez JC, Tiburcio RA, Tokimatu Filho PM, de Lima GMA, Guido RVC, Corrêa TLR, Leme AFP, Mieczkowski P, Pereira GAG. Ceratocystis cacaofunesta genome analysis reveals a large expansion of extracellular phosphatidylinositol-specific phospholipase-C genes (PI-PLC). BMC Genomics 2018; 19:58. [PMID: 29343217 PMCID: PMC5773145 DOI: 10.1186/s12864-018-4440-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 01/08/2018] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND The Ceratocystis genus harbors a large number of phytopathogenic fungi that cause xylem parenchyma degradation and vascular destruction on a broad range of economically important plants. Ceratocystis cacaofunesta is a necrotrophic fungus responsible for lethal wilt disease in cacao. The aim of this work is to analyze the genome of C. cacaofunesta through a comparative approach with genomes of other Sordariomycetes in order to better understand the molecular basis of pathogenicity in the Ceratocystis genus. RESULTS We present an analysis of the C. cacaofunesta genome focusing on secreted proteins that might constitute pathogenicity factors. Comparative genome analyses among five Ceratocystidaceae species and 23 other Sordariomycetes fungi showed a strong reduction in gene content of the Ceratocystis genus. However, some gene families displayed a remarkable expansion, in particular, the Phosphatidylinositol specific phospholipases-C (PI-PLC) family. Also, evolutionary rate calculations suggest that the evolution process of this family was guided by positive selection. Interestingly, among the 82 PI-PLCs genes identified in the C. cacaofunesta genome, 70 genes encoding extracellular PI-PLCs are grouped in eight small scaffolds surrounded by transposon fragments and scars that could be involved in the rapid evolution of the PI-PLC family. Experimental secretome using LC-MS/MS validated 24% (86 proteins) of the total predicted secretome (342 proteins), including four PI-PLCs and other important pathogenicity factors. CONCLUSION Analysis of the Ceratocystis cacaofunesta genome provides evidence that PI-PLCs may play a role in pathogenicity. Subsequent functional studies will be aimed at evaluating this hypothesis. The observed genetic arsenals, together with the analysis of the PI-PLC family shown in this work, reveal significant differences in the Ceratocystis genome compared to the classical vascular fungi, Verticillium and Fusarium. Altogether, our analyses provide new insights into the evolution and the molecular basis of plant pathogenicity.
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Affiliation(s)
- Eddy Patricia Lopez Molano
- Genomic and Expression Laboratory, Department of Genetics, Evolution and Bioagents, Institute of Biology, University of Campinas, Campinas, SP, 13083-970, Brazil
| | - Odalys García Cabrera
- Genomic and Expression Laboratory, Department of Genetics, Evolution and Bioagents, Institute of Biology, University of Campinas, Campinas, SP, 13083-970, Brazil
| | - Juliana Jose
- Genomic and Expression Laboratory, Department of Genetics, Evolution and Bioagents, Institute of Biology, University of Campinas, Campinas, SP, 13083-970, Brazil
| | | | - Marcelo Falsarella Carazzolle
- Genomic and Expression Laboratory, Department of Genetics, Evolution and Bioagents, Institute of Biology, University of Campinas, Campinas, SP, 13083-970, Brazil.,Centro Nacional de Processamento de Alto Desempenho, Universidade Estadual de Campinas, Campinas, Brazil
| | - Paulo José Pereira Lima Teixeira
- Genomic and Expression Laboratory, Department of Genetics, Evolution and Bioagents, Institute of Biology, University of Campinas, Campinas, SP, 13083-970, Brazil.,Present Address: Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Javier Correa Alvarez
- Departamento de Ciencias Biológicas, Escuela de Ciencias, Universidad EAFIT, Medellın, Colombia
| | - Ricardo Augusto Tiburcio
- Genomic and Expression Laboratory, Department of Genetics, Evolution and Bioagents, Institute of Biology, University of Campinas, Campinas, SP, 13083-970, Brazil
| | - Paulo Massanari Tokimatu Filho
- Genomic and Expression Laboratory, Department of Genetics, Evolution and Bioagents, Institute of Biology, University of Campinas, Campinas, SP, 13083-970, Brazil
| | - Gustavo Machado Alvares de Lima
- Centro de Biotecnologia Molecular Estrutural, Instituto de Física de São Carlos, Universidade de São Paulo, São Paulo, Brazil
| | - Rafael Victório Carvalho Guido
- Centro de Biotecnologia Molecular Estrutural, Instituto de Física de São Carlos, Universidade de São Paulo, São Paulo, Brazil
| | - Thamy Lívia Ribeiro Corrêa
- Genomic and Expression Laboratory, Department of Genetics, Evolution and Bioagents, Institute of Biology, University of Campinas, Campinas, SP, 13083-970, Brazil
| | | | - Piotr Mieczkowski
- High-Throughput Sequencing Facility, University of North Carolina, Chapel Hill, NC, USA
| | - Gonçalo Amarante Guimarães Pereira
- Genomic and Expression Laboratory, Department of Genetics, Evolution and Bioagents, Institute of Biology, University of Campinas, Campinas, SP, 13083-970, Brazil.
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Farrer RA, Fisher MC. Describing Genomic and Epigenomic Traits Underpinning Emerging Fungal Pathogens. ADVANCES IN GENETICS 2017; 100:73-140. [PMID: 29153405 DOI: 10.1016/bs.adgen.2017.09.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
An unprecedented number of pathogenic fungi are emerging and causing disease in animals and plants, putting the resilience of wild and managed ecosystems in jeopardy. While the past decades have seen an increase in the number of pathogenic fungi, they have also seen the birth of new big data technologies and analytical approaches to tackle these emerging pathogens. We review how the linked fields of genomics and epigenomics are transforming our ability to address the challenge of emerging fungal pathogens. We explore the methodologies and bioinformatic toolkits that currently exist to rapidly analyze the genomes of unknown fungi, then discuss how these data can be used to address key questions that shed light on their epidemiology. We show how genomic approaches are leading a revolution into our understanding of emerging fungal diseases and speculate on future approaches that will transform our ability to tackle this increasingly important class of emerging pathogens.
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45
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Plasticity of the MFS1 Promoter Leads to Multidrug Resistance in the Wheat Pathogen Zymoseptoria tritici. mSphere 2017; 2:mSphere00393-17. [PMID: 29085913 PMCID: PMC5656749 DOI: 10.1128/msphere.00393-17] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 09/21/2017] [Indexed: 11/20/2022] Open
Abstract
The ascomycete Zymoseptoria tritici is the causal agent of Septoria leaf blotch on wheat. Disease control relies mainly on resistant wheat cultivars and on fungicide applications. The fungus displays a high potential to circumvent both methods. Resistance against all unisite fungicides has been observed over decades. A different type of resistance has emerged among wild populations with multidrug-resistant (MDR) strains. Active fungicide efflux through overexpression of the major facilitator gene MFS1 explains this emerging resistance mechanism. Applying a bulk-progeny sequencing approach, we identified in this study a 519-bp long terminal repeat (LTR) insert in the MFS1 promoter, a relic of a retrotransposon cosegregating with the MDR phenotype. Through gene replacement, we show the insert as a mutation responsible for MFS1 overexpression and the MDR phenotype. Besides this type I insert, we found two different types of promoter inserts in more recent MDR strains. Type I and type II inserts harbor potential transcription factor binding sites, but not the type III insert. Interestingly, all three inserts correspond to repeated elements present at different genomic locations in either IPO323 or other Z. tritici strains. These results underline the plasticity of repeated elements leading to fungicide resistance in Z. tritici and which contribute to its adaptive potential. IMPORTANCE Disease control through fungicides remains an important means to protect crops from fungal diseases and to secure the harvest. Plant-pathogenic fungi, especially Zymoseptoria tritici, have developed resistance against most currently used active ingredients, reducing or abolishing their efficacy. While target site modification is the most common resistance mechanism against single modes of action, active efflux of multiple drugs is an emerging phenomenon in fungal populations reducing additionally fungicides' efficacy in multidrug-resistant strains. We have investigated the mutations responsible for increased drug efflux in Z. tritici field strains. Our study reveals that three different insertions of repeated elements in the same promoter lead to multidrug resistance in Z. tritici. The target gene encodes the membrane transporter MFS1 responsible for drug efflux, with the promoter inserts inducing its overexpression. These results underline the plasticity of repeated elements leading to fungicide resistance in Z. tritici.
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46
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Dallery JF, Lapalu N, Zampounis A, Pigné S, Luyten I, Amselem J, Wittenberg AHJ, Zhou S, de Queiroz MV, Robin GP, Auger A, Hainaut M, Henrissat B, Kim KT, Lee YH, Lespinet O, Schwartz DC, Thon MR, O'Connell RJ. Gapless genome assembly of Colletotrichum higginsianum reveals chromosome structure and association of transposable elements with secondary metabolite gene clusters. BMC Genomics 2017; 18:667. [PMID: 28851275 PMCID: PMC5576322 DOI: 10.1186/s12864-017-4083-x] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 08/21/2017] [Indexed: 11/11/2022] Open
Abstract
Background The ascomycete fungus Colletotrichum higginsianum causes anthracnose disease of brassica crops and the model plant Arabidopsis thaliana. Previous versions of the genome sequence were highly fragmented, causing errors in the prediction of protein-coding genes and preventing the analysis of repetitive sequences and genome architecture. Results Here, we re-sequenced the genome using single-molecule real-time (SMRT) sequencing technology and, in combination with optical map data, this provided a gapless assembly of all twelve chromosomes except for the ribosomal DNA repeat cluster on chromosome 7. The more accurate gene annotation made possible by this new assembly revealed a large repertoire of secondary metabolism (SM) key genes (89) and putative biosynthetic pathways (77 SM gene clusters). The two mini-chromosomes differed from the ten core chromosomes in being repeat- and AT-rich and gene-poor but were significantly enriched with genes encoding putative secreted effector proteins. Transposable elements (TEs) were found to occupy 7% of the genome by length. Certain TE families showed a statistically significant association with effector genes and SM cluster genes and were transcriptionally active at particular stages of fungal development. All 24 subtelomeres were found to contain one of three highly-conserved repeat elements which, by providing sites for homologous recombination, were probably instrumental in four segmental duplications. Conclusion The gapless genome of C. higginsianum provides access to repeat-rich regions that were previously poorly assembled, notably the mini-chromosomes and subtelomeres, and allowed prediction of the complete SM gene repertoire. It also provides insights into the potential role of TEs in gene and genome evolution and host adaptation in this asexual pathogen. Electronic supplementary material The online version of this article (10.1186/s12864-017-4083-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jean-Félix Dallery
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, Thiverval-Grignon, France
| | - Nicolas Lapalu
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, Thiverval-Grignon, France
| | - Antonios Zampounis
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, Thiverval-Grignon, France.,Present Address: Department of Deciduous Fruit Trees, Institute of Plant Breeding and Plant Genetic Resources, Hellenic Agricultural Organization 'Demeter', Naoussa, Greece
| | - Sandrine Pigné
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, Thiverval-Grignon, France
| | | | | | | | - Shiguo Zhou
- Laboratory for Molecular and Computational Genomics, Department of Chemistry, Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Marisa V de Queiroz
- Laboratório de Genética Molecular de Fungos, Universidade Federal de Viçosa, Viçosa, Brazil
| | - Guillaume P Robin
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, Thiverval-Grignon, France
| | - Annie Auger
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, Thiverval-Grignon, France
| | - Matthieu Hainaut
- CNRS UMR 7257, Aix-Marseille University, Marseille, France.,INRA, USC 1408 AFMB, Marseille, France
| | - Bernard Henrissat
- CNRS UMR 7257, Aix-Marseille University, Marseille, France.,INRA, USC 1408 AFMB, Marseille, France.,Department of Biological Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Ki-Tae Kim
- Department of Agricultural Biotechnology, Center for Fungal Genetic Resources, Seoul National University, Seoul, Korea
| | - Yong-Hwan Lee
- Department of Agricultural Biotechnology, Center for Fungal Genetic Resources, Seoul National University, Seoul, Korea
| | - Olivier Lespinet
- Laboratoire de Recherche en Informatique, CNRS, Université Paris-Sud, Orsay, France.,Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Orsay, France
| | - David C Schwartz
- Laboratory for Molecular and Computational Genomics, Department of Chemistry, Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Michael R Thon
- Instituto Hispano-Luso de Investigaciones Agrarias (CIALE), Department of Microbiology and Genetics, University of Salamanca, Salamanca, Spain
| | - Richard J O'Connell
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, Thiverval-Grignon, France.
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47
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Donnart T, Piednoël M, Higuet D, Bonnivard É. Filamentous ascomycete genomes provide insights into Copia retrotransposon diversity in fungi. BMC Genomics 2017; 18:410. [PMID: 28545447 PMCID: PMC5445492 DOI: 10.1186/s12864-017-3795-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 05/16/2017] [Indexed: 12/31/2022] Open
Abstract
Background The relative scarcity of Copia retrotransposons has been recently characterized in metazoans in comparison with the other superfamilies of LTR elements. Furthermore, Copia retrotransposons have often a particular dynamics that results in a highly predominant single clade of elements within a large host taxon, such as the GalEa-like retrotransposons in crustaceans. Taking advantage of the skyrocketing amount of genomic data available for fungi, we carried out the first large-scale comparative genomic analysis of the Copia clades in filamentous ascomycetes. Results Screening 30 completely sequenced genomes allowed us to identify more than 2500 Copia copies with conserved LTR, which are distributed in 138 families. Their characterization revealed that fungal Copia diversity is much broader than previously thought with at least 27 clades, 23 of which likely correspond to new ones. While the Copia copy number is low in most species, the two clades GalEa and FunCo1 are widely distributed and highly dominate Copia content as they both account for 80% of the detected sequences. Conclusions In Fungi, GalEa retrotransposons are restricted to Pezizomycotina in which they can make up an outstandingly high proportion of the genome (up to 10% in Cenococcum geophilum). At last, we revealed that fungal GalEa elements structurally differ from all other Copia elements with an absence of Primer Binding Site. These elements however harbor a Conserved Hairpin Site which is probably essential for their transposition. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3795-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Tifenn Donnart
- Sorbonne Universités, UPMC Univ Paris 06, Univ Antilles, Univ Nice Sophia Antipolis, CNRS, Evolution Paris Seine - Institut de Biologie Paris Seine (EPS - IBPS), 75005, Paris, France
| | - Mathieu Piednoël
- Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Carl-von-Linné Weg 10, D-50829, Cologne, Germany
| | - Dominique Higuet
- Sorbonne Universités, UPMC Univ Paris 06, Univ Antilles, Univ Nice Sophia Antipolis, CNRS, Evolution Paris Seine - Institut de Biologie Paris Seine (EPS - IBPS), 75005, Paris, France
| | - Éric Bonnivard
- Sorbonne Universités, UPMC Univ Paris 06, Univ Antilles, Univ Nice Sophia Antipolis, CNRS, Evolution Paris Seine - Institut de Biologie Paris Seine (EPS - IBPS), 75005, Paris, France.
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48
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DNA sequence homology induces cytosine-to-thymine mutation by a heterochromatin-related pathway in Neurospora. Nat Genet 2017; 49:887-894. [PMID: 28459455 PMCID: PMC5474309 DOI: 10.1038/ng.3857] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 03/31/2017] [Indexed: 12/16/2022]
Abstract
Eukaryotic genomes contain substantial amounts of repetitive DNA organized in the form of constitutive heterochromatin and associated with repressive epigenetic modifications, such as H3K9me3 and C5-cytosine methylation (5mC). In the fungus Neurospora crassa, H3K9me3 and 5mC are catalyzed, respectively, by a conserved SUV39 histone methyltransferase DIM-5 and a DNMT1-like cytosine methyltransferase DIM-2. Here we show that DIM-2 can also mediate Repeat-Induced Point mutation (RIP) of repetitive DNA in N. crassa. We further show that DIM-2-dependent RIP requires DIM-5, HP1, and other known heterochromatin factors, implying the role of a repeat-induced heterochromatin-related process. Our previous findings suggest that the mechanism of repeat recognition for RIP involves direct interactions between homologous double-stranded (ds) DNA segments. We thus now propose that, in somatic cells, homologous dsDNA/dsDNA interactions between a small number of repeat copies can nucleate a transient heterochromatic state, which, on longer repeat arrays, may lead to the formation of constitutive heterochromatin.
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49
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Clutterbuck AJ. Genomic CG dinucleotide deficiencies associated with transposable element hypermutation in Basidiomycetes, some lower fungi, a moss and a clubmoss. Fungal Genet Biol 2017; 104:16-28. [PMID: 28438577 DOI: 10.1016/j.fgb.2017.04.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 04/10/2017] [Accepted: 04/17/2017] [Indexed: 12/15/2022]
Abstract
Many Basidiomycete genomes include substantial fractions that are deficient in CG dinucleotides, in extreme cases amounting to 70% of the genome. CG deficiency is variable and correlates with genome size and, more closely, with transposable element (TE) content. Many species have limited CG deficiency; it is therefore likely that there are other mechanisms that can control TE proliferation. Examination of TEs confirms that C-to-T transition mutations in CG dinucleotides may comprise a conspicuous proportion of differences between paired elements, however transition/transversion ratios are never as high as those due to RIP in some Ascomycetes, suggesting that repeat-associated CG mutation is not totally pervasive. This has allowed gene family expansion in Basidiomycetes, although CG transition differences are often prominent in paired gene family members, and are evidently responsible for destruction of some copies. A few lower fungal genomes exhibit similar evidence of repeat-associated CG mutation, as do the genomes of the two lower plants Physcomitrella patens and Selaginella moellendorffii, in both of which mutation parallels published methylation of CHG as well as CG nucleotides. In Basidiomycete DNA methylation has been reported to be largely confined to CG dinucleotides in repetitive DNA, but while methylation and mutation are evidently associated, it is not clear which is cause and which effect.
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Affiliation(s)
- A John Clutterbuck
- Wolfson Link Building, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, UK.
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50
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Derbyshire M, Denton-Giles M, Hegedus D, Seifbarghy S, Rollins J, van Kan J, Seidl MF, Faino L, Mbengue M, Navaud O, Raffaele S, Hammond-Kosack K, Heard S, Oliver R. The complete genome sequence of the phytopathogenic fungus Sclerotinia sclerotiorum reveals insights into the genome architecture of broad host range pathogens. Genome Biol Evol 2017; 9:593-618. [PMID: 28204478 PMCID: PMC5381539 DOI: 10.1093/gbe/evx030] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 01/16/2017] [Accepted: 02/08/2017] [Indexed: 12/19/2022] Open
Abstract
Sclerotinia sclerotiorum is a phytopathogenic fungus with over 400 hosts including numerous economically important cultivated species. This contrasts many economically destructive pathogens that only exhibit a single or very few hosts. Many plant pathogens exhibit a “two-speed” genome. So described because their genomes contain alternating gene rich, repeat sparse and gene poor, repeat-rich regions. In fungi, the repeat-rich regions may be subjected to a process termed repeat-induced point mutation (RIP). Both repeat activity and RIP are thought to play a significant role in evolution of secreted virulence proteins, termed effectors. We present a complete genome sequence of S. sclerotiorum generated using Single Molecule Real-Time Sequencing technology with highly accurate annotations produced using an extensive RNA sequencing data set. We identified 70 effector candidates and have highlighted their in planta expression profiles. Furthermore, we characterized the genome architecture of S. sclerotiorum in comparison to plant pathogens that exhibit “two-speed” genomes. We show that there is a significant association between positions of secreted proteins and regions with a high RIP index in S. sclerotiorum but we did not detect a correlation between secreted protein proportion and GC content. Neither did we detect a negative correlation between CDS content and secreted protein proportion across the S. sclerotiorum genome. We conclude that S. sclerotiorum exhibits subtle signatures of enhanced mutation of secreted proteins in specific genomic compartments as a result of transposition and RIP activity. However, these signatures are not observable at the whole-genome scale.
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Affiliation(s)
- Mark Derbyshire
- Centre for Crop and Disease Management Department of Environment and Agriculture, Curtin University, Bentley, Perth, Western Australia, Australia
| | - Matthew Denton-Giles
- Centre for Crop and Disease Management Department of Environment and Agriculture, Curtin University, Bentley, Perth, Western Australia, Australia
| | - Dwayne Hegedus
- Agriculture and Agri-Food Canada, Saskatoon, Saskatchewan, Canada
| | | | - Jeffrey Rollins
- Department of Plant Pathology, University of Florida, Gainesville, FL
| | - Jan van Kan
- Laboratory of Phytopathology, Wageningen University, The Netherlands
| | - Michael F. Seidl
- Laboratory of Phytopathology, Wageningen University, The Netherlands
| | - Luigi Faino
- Laboratory of Phytopathology, Wageningen University, The Netherlands
| | - Malick Mbengue
- LIPM Université de Toulouse INRA CNRS, Castanet-Tolosan, France
| | - Olivier Navaud
- LIPM Université de Toulouse INRA CNRS, Castanet-Tolosan, France
| | | | - Kim Hammond-Kosack
- Department of Plant Biology and Crop Sciences, Rothamsted Research, Harpenden, Hertfordshire, United Kingdom
| | - Stephanie Heard
- Department of Plant Pathology, University of Florida, Gainesville, FL
- Department of Plant Biology and Crop Sciences, Rothamsted Research, Harpenden, Hertfordshire, United Kingdom
| | - Richard Oliver
- Centre for Crop and Disease Management Department of Environment and Agriculture, Curtin University, Bentley, Perth, Western Australia, Australia
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