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Lin L, Sun T, Guo J, Lin L, Chen M, Wang Z, Bao J, Norvienyeku J, Zhang D, Han Y, Lu G, Rensing C, Zheng H, Zhong Z, Wang Z. Transposable elements impact the population divergence of rice blast fungus Magnaporthe oryzae. mBio 2024; 15:e0008624. [PMID: 38534157 PMCID: PMC11077969 DOI: 10.1128/mbio.00086-24] [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: 01/13/2024] [Accepted: 03/06/2024] [Indexed: 03/28/2024] Open
Abstract
Dynamic transposition of transposable elements (TEs) in fungal pathogens has significant impact on genome stability, gene expression, and virulence to the host. In Magnaporthe oryzae, genome plasticity resulting from TE insertion is a major driving force leading to the rapid evolution and diversification of this fungus. Despite their importance in M. oryzae population evolution and divergence, our understanding of TEs in this context remains limited. Here, we conducted a genome-wide analysis of TE transposition dynamics in the 11 most abundant TE families in M. oryzae populations. Our results show that these TEs have specifically expanded in recently isolated M. oryzae rice populations, with the presence/absence polymorphism of TE insertions highly concordant with population divergence on Geng/Japonica and Xian/Indica rice cultivars. Notably, the genes targeted by clade-specific TEs showed clade-specific expression patterns and are involved in the pathogenic process, suggesting a transcriptional regulation of TEs on targeted genes. Our study provides a comprehensive analysis of TEs in M. oryzae populations and demonstrates a crucial role of recent TE bursts in adaptive evolution and diversification of the M. oryzae rice-infecting lineage. IMPORTANCE Magnaporthe oryzae is the causal agent of the destructive blast disease, which caused massive loss of yield annually worldwide. The fungus diverged into distinct clades during adaptation toward the two rice subspecies, Xian/Indica and Geng/Japonica. Although the role of TEs in the adaptive evolution was well established, mechanisms underlying how TEs promote the population divergence of M. oryzae remain largely unknown. In this study, we reported that TEs shape the population divergence of M. oryzae by differentially regulating gene expression between Xian/Indica-infecting and Geng/Japonica-infecting populations. Our results revealed a TE insertion-mediated gene expression adaption that led to the divergence of M. oryzae population infecting different rice subspecies.
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Affiliation(s)
- Lianyu Lin
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Ting Sun
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Jiayuan Guo
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, China
- Fuzhou Institute of Oceanography, Minjiang University, Fuzhou, China
| | - Lili Lin
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Meilian Chen
- Fuzhou Institute of Oceanography, Minjiang University, Fuzhou, China
| | - Zhe Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Jiandong Bao
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-Products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Justice Norvienyeku
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, College of Plant Protection, Hainan University, Haikou, China
| | - Dongmei Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yijuan Han
- Fuzhou Institute of Oceanography, Minjiang University, Fuzhou, China
| | - Guodong Lu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Christopher Rensing
- Institute of Environmental Microbiology, College of Resource and Environment, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Huakun Zheng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Zhenhui Zhong
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, China
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Sciences, Sichuan University, Chengdu, China
| | - Zonghua Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, China
- Fuzhou Institute of Oceanography, Minjiang University, Fuzhou, China
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Clemons RA, Yacoub MN, Faust E, Toledo LF, Jenkinson TS, Carvalho T, Simmons DR, Kalinka E, Fritz-Laylin LK, James TY, Stajich JE. An endogenous DNA virus in an amphibian-killing fungus associated with pathogen genotype and virulence. Curr Biol 2024; 34:1469-1478.e6. [PMID: 38490202 DOI: 10.1016/j.cub.2024.02.062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 12/18/2023] [Accepted: 02/26/2024] [Indexed: 03/17/2024]
Abstract
The global panzootic lineage (GPL) of the pathogenic fungus Batrachochytrium dendrobatidis (Bd) has caused severe amphibian population declines, yet the drivers underlying the high frequency of GPL in regions of amphibian decline are unclear. Using publicly available Bd genome sequences, we identified multiple non-GPL Bd isolates that contain a circular Rep-encoding single-stranded (CRESS)-like DNA virus, which we named Bd DNA virus 1 (BdDV-1). We further sequenced and constructed genome assemblies with long read sequences to find that the virus is integrated into the nuclear genome in some strains. Attempts to cure virus-positive isolates were unsuccessful; however, phenotypic differences between naturally virus-positive and virus-negative Bd isolates suggested that BdDV-1 decreases the growth of its host in vitro but increases the virulence of its host in vivo. BdDV-1 is the first-described CRESS DNA mycovirus of zoosporic true fungi, with a distribution inversely associated with the emergence of the panzootic lineage.
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Affiliation(s)
- Rebecca A Clemons
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Mark N Yacoub
- Department of Microbiology and Plant Pathology, University of California, Riverside, Riverside, CA 92521, USA
| | - Evelyn Faust
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - L Felipe Toledo
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal Instituto de Biologia (IB), Universidade Estadual de Campinas, Campinas, SP 13083-862, Brazil
| | - Thomas S Jenkinson
- Department of Biological Sciences, California State University, East Bay, Hayward, CA 94592, USA
| | - Tamilie Carvalho
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - D Rabern Simmons
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Erik Kalinka
- Department of Biology, University of Massachusetts, Amherst, Amherst, MA 01003, USA
| | | | - Timothy Y James
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Jason E Stajich
- Department of Microbiology and Plant Pathology, University of California, Riverside, Riverside, CA 92521, USA.
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3
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Garcia JF, Morales-Cruz A, Cochetel N, Minio A, Figueroa-Balderas R, Rolshausen PE, Baumgartner K, Cantu D. Comparative Pangenomic Insights into the Distinct Evolution of Virulence Factors Among Grapevine Trunk Pathogens. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2024; 37:127-142. [PMID: 37934016 DOI: 10.1094/mpmi-09-23-0129-r] [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: 11/08/2023]
Abstract
The permanent organs of grapevines (Vitis vinifera L.), like those of other woody perennials, are colonized by various unrelated pathogenic ascomycete fungi secreting cell wall-degrading enzymes and phytotoxic secondary metabolites that contribute to host damage and disease symptoms. Trunk pathogens differ in the symptoms they induce and the extent and speed of damage. Isolates of the same species often display a wide virulence range, even within the same vineyard. This study focuses on Eutypa lata, Neofusicoccum parvum, and Phaeoacremonium minimum, causal agents of Eutypa dieback, Botryosphaeria dieback, and Esca, respectively. We sequenced 50 isolates from viticulture regions worldwide and built nucleotide-level, reference-free pangenomes for each species. Through examination of genomic diversity and pangenome structure, we analyzed intraspecific conservation and variability of putative virulence factors, focusing on functions under positive selection and recent gene family dynamics of contraction and expansion. Our findings reveal contrasting distributions of putative virulence factors in the core, dispensable, and private genomes of each pangenome. For example, carbohydrate active enzymes (CAZymes) were prevalent in the core genomes of each pangenome, whereas biosynthetic gene clusters were prevalent in the dispensable genomes of E. lata and P. minimum. The dispensable fractions were also enriched in Gypsy transposable elements and virulence factors under positive selection (polyketide synthase genes in E. lata and P. minimum, glycosyltransferases in N. parvum). Our findings underscore the complexity of the genomic architecture in each species and provide insights into their adaptive strategies, enhancing our understanding of the underlying mechanisms of virulence. [Formula: see text] Copyright © 2024 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)
- Jadran F Garcia
- Department of Viticulture and Enology, University of California, Davis, Davis, CA, U.S.A
| | - Abraham Morales-Cruz
- Department of Viticulture and Enology, University of California, Davis, Davis, CA, U.S.A
- U.S. Department of Energy, Joint Genome Institute, Lawrence Berkeley National Lab, Berkeley, CA, U.S.A
| | - Noé Cochetel
- Department of Viticulture and Enology, University of California, Davis, Davis, CA, U.S.A
| | - Andrea Minio
- Department of Viticulture and Enology, University of California, Davis, Davis, CA, U.S.A
| | - Rosa Figueroa-Balderas
- Department of Viticulture and Enology, University of California, Davis, Davis, CA, U.S.A
| | - Philippe E Rolshausen
- Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA, U.S.A
| | - Kendra Baumgartner
- Crops Pathology and Genetics Research Unit, U.S. Department of Agriculture-Agricultural Research Service, Davis, CA, U.S.A
| | - Dario Cantu
- Department of Viticulture and Enology, University of California, Davis, Davis, CA, U.S.A
- Genome Center, University of California, Davis, Davis, CA, U.S.A
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4
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Treindl AD, Stapley J, Croll D, Leuchtmann A. Two-speed genomes of Epichloe fungal pathogens show contrasting signatures of selection between species and across populations. Mol Ecol 2024; 33:e17242. [PMID: 38084851 DOI: 10.1111/mec.17242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 11/23/2023] [Accepted: 11/30/2023] [Indexed: 12/19/2023]
Abstract
Antagonistic selection between pathogens and their hosts can drive rapid evolutionary change and leave distinct molecular footprints of past and ongoing selection in the genomes of the interacting species. Despite an increasing availability of tools able to identify signatures of selection, the genetic mechanisms underlying coevolutionary interactions and the specific genes involved are still poorly understood, especially in heterogeneous natural environments. We searched the genomes of two species of Epichloe plant pathogen for evidence of recent selection. The Epichloe genus includes highly host-specific species that can sterilize their grass hosts. We performed selection scans using genome-wide SNP data from seven natural populations of two co-occurring Epichloe sibling species specialized on different hosts. We found evidence of recent (and ongoing) selective sweeps across the genome in both species. However, selective sweeps were more abundant in the species with a larger effective population size. Sweep regions often overlapped with highly polymorphic AT-rich regions supporting the role of these genome compartments in adaptive evolution. Although most loci under selection were specific to individual populations, we could also identify several candidate genes targeted by selection in sweep regions shared among populations. The genes encoded small secreted proteins typical of fungal effectors and cell wall-degrading enzymes. By investigating the genomic signatures of selection across multiple populations and species, this study contributes to our understanding of complex adaptive processes in natural plant pathogen systems.
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Affiliation(s)
- Artemis D Treindl
- Plant Ecological Genetics Group, Institute of Integrative Biology, ETH Zurich, Zurich, Switzerland
- Biodiversity and Conservation Biology, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Jessica Stapley
- Plant Pathology Group, Institute of Integrative Biology, ETH Zurich, Zurich, Switzerland
| | - Daniel Croll
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Adrian Leuchtmann
- Plant Ecological Genetics Group, Institute of Integrative Biology, ETH Zurich, Zurich, Switzerland
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5
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Stapley J, McDonald BA. Quantitative trait locus mapping of osmotic stress response in the fungal wheat pathogen Zymoseptoria tritici. G3 (BETHESDA, MD.) 2023; 13:jkad226. [PMID: 37774498 PMCID: PMC10700024 DOI: 10.1093/g3journal/jkad226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 09/19/2023] [Accepted: 09/20/2023] [Indexed: 10/01/2023]
Abstract
Osmotic stress is a ubiquitous and potent stress for all living organisms, but few studies have investigated the genetic basis of salt tolerance in filamentous fungi. The main aim of this study was to identify regions of the genome associated with tolerance to potassium chloride (KCl) in the wheat pathogen Zymoseptoria tritici. A secondary aim was to identify candidate genes affecting salt tolerance within the most promising chromosomal regions. We achieved these aims with a quantitative trait locus (QTL) mapping study using offspring from 2 crosses grown in vitro in the presence or absence of osmotic stress imposed by 0.75 M KCl. We identified significant QTL for most of the traits in both crosses. Several QTLs overlapped with QTL identified in earlier studies for other traits, and some QTL explained trait variation in both the control and salt stress environments. A significant QTL on chromosome 3 explained variation in colony radius at 8-day postinoculation (dpi) in the KCl environment as well as colony radius KCl tolerance at 8 dpi. The QTL peak had a high logarithm of the odds ratio (LOD) and encompassed an interval containing only 36 genes. Six of these genes present promising candidates for functional analyses. A gene ontology (GO) enrichment analysis of QTL unique to the KCl environment found evidence for the enrichment of functions involved in osmotic stress responses.
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Affiliation(s)
- Jessica Stapley
- Plant Pathology Group, Institute of Integrative Biology, ETH Zurich, Zürich 8092, Switzerland
| | - Bruce A McDonald
- Plant Pathology Group, Institute of Integrative Biology, ETH Zurich, Zürich 8092, Switzerland
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6
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Baril T, Croll D. A pangenome-guided manually curated library of transposable elements for Zymoseptoria tritici. BMC Res Notes 2023; 16:335. [PMID: 37974222 PMCID: PMC10652580 DOI: 10.1186/s13104-023-06613-7] [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: 09/29/2023] [Accepted: 11/03/2023] [Indexed: 11/19/2023] Open
Abstract
OBJECTIVES High-quality species-specific transposable element (TE) libraries are required for studies to elucidate the evolutionary dynamics of TEs and gain an understanding of their impacts on host genomes. Such high-quality TE resources are severely lacking for species in the fungal kingdom. To facilitate future studies on the putative role of TEs in rapid adaptation observed in the fungal wheat pathogen Zymoseptoria tritici, we produced a manually curated TE library. This was generated by detecting TEs in 19 reference genome assemblies representing the global diversity of the species supplemented by multiple sister species genomes. Improvements over previous TE libraries have been made on TE boundary resolution, detection of ORFs, TE domains, terminal inverted repeats, and class-specific motifs. DATA DESCRIPTION A TE consensus library for Z. tritici formatted for use with RepeatMasker. This data is relevant to other researchers investigating TE-host evolutionary dynamics in Z. tritici or who are interested in comparative studies of the fungal kingdom. Further, this TE library can be used to improve gene annotation. Finally, this TE library increases the number of manually curated TE datasets, providing resources to further our understanding of TE diversity.
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Affiliation(s)
- Tobias Baril
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchatel, Rue -Argand 11, 2000, Neuchatel, Switzerland
| | - Daniel Croll
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchatel, Rue -Argand 11, 2000, Neuchatel, Switzerland.
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7
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Glad HM, Tralamazza SM, Croll D. The expression landscape and pangenome of long non-coding RNA in the fungal wheat pathogen Zymoseptoria tritici. Microb Genom 2023; 9. [PMID: 37991492 DOI: 10.1099/mgen.0.001136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2023] Open
Abstract
Long non-coding RNAs (lncRNAs) are regulatory molecules interacting in a wide array of biological processes. lncRNAs in fungal pathogens can be responsive to stress and play roles in regulating growth and nutrient acquisition. Recent evidence suggests that lncRNAs may also play roles in virulence, such as regulating pathogenicity-associated enzymes and on-host reproductive cycles. Despite the importance of lncRNAs, only a few model fungi have well-documented inventories of lncRNA. In this study, we apply a recent computational pipeline to predict high-confidence lncRNA candidates in Zymoseptoria tritici, an important global pathogen of wheat impacting global food production. We analyse genomic features of lncRNAs and the most likely associated processes through analyses of expression over a host infection cycle. We find that lncRNAs are frequently expressed during early infection, before the switch to necrotrophic growth. They are mostly located in facultative heterochromatic regions, which are known to contain many genes associated with pathogenicity. Furthermore, we find that lncRNAs are frequently co-expressed with genes that may be involved in responding to host defence signals, such as oxidative stress. Finally, we assess pangenome features of lncRNAs using four additional reference-quality genomes. We find evidence that the repertoire of expressed lncRNAs varies substantially between individuals, even though lncRNA loci tend to be shared at the genomic level. Overall, this study provides a repertoire and putative functions of lncRNAs in Z. tritici enabling future molecular genetics and functional analyses in an important pathogen.
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Affiliation(s)
- Hanna M Glad
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, 2000 Neuchâtel, Switzerland
| | - Sabina Moser Tralamazza
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, 2000 Neuchâtel, Switzerland
| | - Daniel Croll
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, 2000 Neuchâtel, Switzerland
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8
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Welgemoed T, Duong TA, Barnes I, Stukenbrock EH, Berger DK. Population genomic analyses suggest recent dispersal events of the pathogen Cercospora zeina into East and Southern African maize cropping systems. G3 (BETHESDA, MD.) 2023; 13:jkad214. [PMID: 37738420 PMCID: PMC10627275 DOI: 10.1093/g3journal/jkad214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 08/03/2023] [Accepted: 09/06/2023] [Indexed: 09/24/2023]
Abstract
A serious factor hampering global maize production is gray leaf spot disease. Cercospora zeina is one of the causative pathogens, but population genomics analysis of C. zeina is lacking. We conducted whole-genome Illumina sequencing of a representative set of 30 C. zeina isolates from Kenya and Uganda (East Africa) and Zambia, Zimbabwe, and South Africa (Southern Africa). Selection of the diverse set was based on microsatellite data from a larger collection of the pathogen. Pangenome analysis of the C. zeina isolates was done by (1) de novo assembly of the reads with SPAdes, (2) annotation with BRAKER, and (3) protein clustering with OrthoFinder. A published long-read assembly of C. zeina (CMW25467) from Zambia was included and annotated using the same pipeline. This analysis revealed 790 non-shared accessory and 10,677 shared core orthogroups (genes) between the 31 isolates. Accessory gene content was largely shared between isolates from all countries, with a few genes unique to populations from Southern Africa (32) or East Africa (6). There was a significantly higher proportion of effector genes in the accessory secretome (44%) compared to the core secretome (24%). PCA, ADMIXTURE, and phylogenetic analysis using a neighbor-net network indicated a population structure with a geographical subdivision between the East African isolates and the Southern African isolates, although gene flow was also evident. The small pangenome and partial population differentiation indicated recent dispersal of C. zeina into Africa, possibly from 2 regional founder populations, followed by recurrent gene flow owing to widespread maize production across sub-Saharan Africa.
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Affiliation(s)
- Tanya Welgemoed
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Tuan A Duong
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Irene Barnes
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Eva H Stukenbrock
- Environmental Genomics, Christian-Albrechts University of Kiel, Am Botanischen Garten 1-11, Kiel 24118, Germany
- Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, Plön 24306, Germany
| | - Dave K Berger
- Department of Plant and Soil Sciences, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
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9
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Fones HN, Soanes D, Gurr SJ. Epiphytic proliferation of Zymoseptoria tritici isolates on resistant wheat leaves. Fungal Genet Biol 2023; 168:103822. [PMID: 37343618 DOI: 10.1016/j.fgb.2023.103822] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 06/04/2023] [Accepted: 06/15/2023] [Indexed: 06/23/2023]
Abstract
The wheat pathogen Zymoseptoria tritici is capable of a long period of pre-invasive epiphytic growth. Studies have shown that virulent isolates vary in the extent, duration and growth form of this epiphytic growth, and the fungus has been observed to undergo behaviours such as asexual reproduction by budding and vegetative fusion of hyphae on the leaf surface. This epiphytic colonisation has been investigated very little during interactions in which an isolate of Z. tritici is unable to colonise the apoplast, as occurs during avirulence. However, avirulent isolates have been seen to undergo sexual crosses in the absense of leaf penetration, and it is widely accepted that the main point of distinction between virulent and avirulent isolates occurs at the point of attempted leaf penetration or attempted apoplastic growth, which fails in the avirulent case. In this work, we describe extensive epiphytic growth in three isolates which are unable or have very limited ability to invade the leaf, and show that growth form is as variable as for fully virulent isolates. We demonstrate that during certain interactions, Z. tritici isolates rarely invade the leaf and form pycnidia, but induce necrosis. These isolates are able to achieve higher epiphytic biomass than fully virulent isolates during asymptomatic growth, and may undergo very extensive asexual reproduction on the leaf surface. These findings have implications for open questions such as whether and how Z. tritici obtains nutrients on the leaf surface and the nature of its interaction with wheat defences.
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Affiliation(s)
- H N Fones
- Biosciences, University of Exeter, Exeter, UK
| | - D Soanes
- University of Exeter Medical School, Exeter, UK
| | - S J Gurr
- Biosciences, University of Exeter, Exeter, UK; Department of Biosciences, Utrecht University, Utrecht, the Netherlands.
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10
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Milner DS, Galindo LJ, Irwin NAT, Richards TA. Transporter Proteins as Ecological Assets and Features of Microbial Eukaryotic Pangenomes. Annu Rev Microbiol 2023; 77:45-66. [PMID: 36944262 DOI: 10.1146/annurev-micro-032421-115538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
Here we review two connected themes in evolutionary microbiology: (a) the nature of gene repertoire variation within species groups (pangenomes) and (b) the concept of metabolite transporters as accessory proteins capable of providing niche-defining "bolt-on" phenotypes. We discuss the need for improved sampling and understanding of pangenome variation in eukaryotic microbes. We then review the factors that shape the repertoire of accessory genes within pangenomes. As part of this discussion, we outline how gene duplication is a key factor in both eukaryotic pangenome variation and transporter gene family evolution. We go on to outline how, through functional characterization of transporter-encoding genes, in combination with analyses of how transporter genes are gained and lost from accessory genomes, we can reveal much about the niche range, the ecology, and the evolution of virulence of microbes. We advocate for the coordinated systematic study of eukaryotic pangenomes through genome sequencing and the functional analysis of genes found within the accessory gene repertoire.
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Affiliation(s)
- David S Milner
- Department of Biology, University of Oxford, Oxford, United Kingdom;
| | | | - Nicholas A T Irwin
- Department of Biology, University of Oxford, Oxford, United Kingdom;
- Merton College, University of Oxford, Oxford, United Kingdom
| | - Thomas A Richards
- Department of Biology, University of Oxford, Oxford, United Kingdom;
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11
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Ababa G. Biology, taxonomy, genetics, and management of Zymoseptoria tritici: the causal agent of wheat leaf blotch. Mycology 2023; 14:292-315. [PMID: 38187886 PMCID: PMC10769150 DOI: 10.1080/21501203.2023.2241492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 07/22/2023] [Indexed: 01/09/2024] Open
Abstract
Septoria tritici blotch or Septoria leaf blotch has been used for long time, but leaf blotch is a correct disease name. Moreover, Lb resistant gene is the correct name, but, not Stb gene. It has sexual and asexual parts on the mycelia, known as heterothallic fungi. Its pathogenic diversity ranged from 40% to 93% and has produced a wide variety of AvrLb6 haplotypes. M. graminicola has a plasmogamy and karyogamy sexual process. The pathogen can use macropycnidiospores, micropycnidiospores, and pycnidia vegetative growths for infection and overwintering. Synthetic M3, Kavkaz-K4500, Synthetic 6×, and TE9111 wheat genotypes have horizontal resistance. Avirulence (Avr) genes in Z. tritici and their matching wheat (R) genes indicate gene for gene mechanisms of resistance. Twenty-two R genes (vertical resistance) have been identified. In both horizontal and vertical resistance, different Lb genes have been broken down due to new Z.tritici virulent gene and currently Lb19 resistant gene is being recommended. Mixing of resistant and susceptible cultivars is also the most effective management strategy. Moreover, different cultural practices and biological control have been proposed. Lastly, different fungicides are also available. However, in developing countries cultivar mixture, isolates diversity, biological control, and epidemic studies have been greatly missed.
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Affiliation(s)
- Girma Ababa
- Department of Plant Protection (Plant Pathology), Holetta Agricultural Research Center (HARC), Ethiopian Institute of Agricultural Research (EIAR), Holetta, Addis Ababa, Ethiopia
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12
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Wang Z, Kim W, Wang YW, Yakubovich E, Dong C, Trail F, Townsend JP, Yarden O. The Sordariomycetes: an expanding resource with Big Data for mining in evolutionary genomics and transcriptomics. FRONTIERS IN FUNGAL BIOLOGY 2023; 4:1214537. [PMID: 37746130 PMCID: PMC10512317 DOI: 10.3389/ffunb.2023.1214537] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Accepted: 06/06/2023] [Indexed: 09/26/2023]
Abstract
Advances in genomics and transcriptomics accompanying the rapid accumulation of omics data have provided new tools that have transformed and expanded the traditional concepts of model fungi. Evolutionary genomics and transcriptomics have flourished with the use of classical and newer fungal models that facilitate the study of diverse topics encompassing fungal biology and development. Technological advances have also created the opportunity to obtain and mine large datasets. One such continuously growing dataset is that of the Sordariomycetes, which exhibit a richness of species, ecological diversity, economic importance, and a profound research history on amenable models. Currently, 3,574 species of this class have been sequenced, comprising nearly one-third of the available ascomycete genomes. Among these genomes, multiple representatives of the model genera Fusarium, Neurospora, and Trichoderma are present. In this review, we examine recently published studies and data on the Sordariomycetes that have contributed novel insights to the field of fungal evolution via integrative analyses of the genetic, pathogenic, and other biological characteristics of the fungi. Some of these studies applied ancestral state analysis of gene expression among divergent lineages to infer regulatory network models, identify key genetic elements in fungal sexual development, and investigate the regulation of conidial germination and secondary metabolism. Such multispecies investigations address challenges in the study of fungal evolutionary genomics derived from studies that are often based on limited model genomes and that primarily focus on the aspects of biology driven by knowledge drawn from a few model species. Rapidly accumulating information and expanding capabilities for systems biological analysis of Big Data are setting the stage for the expansion of the concept of model systems from unitary taxonomic species/genera to inclusive clusters of well-studied models that can facilitate both the in-depth study of specific lineages and also investigation of trait diversity across lineages. The Sordariomycetes class, in particular, offers abundant omics data and a large and active global research community. As such, the Sordariomycetes can form a core omics clade, providing a blueprint for the expansion of our knowledge of evolution at the genomic scale in the exciting era of Big Data and artificial intelligence, and serving as a reference for the future analysis of different taxonomic levels within the fungal kingdom.
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Affiliation(s)
- Zheng Wang
- Department of Biostatistics, Yale School of Public Health, New Haven, CT, United States
| | - Wonyong Kim
- Korean Lichen Research Institute, Sunchon National University, Suncheon, Republic of Korea
| | - Yen-Wen Wang
- Department of Biostatistics, Yale School of Public Health, New Haven, CT, United States
| | - Elizabeta Yakubovich
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Caihong Dong
- Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Frances Trail
- Department of Plant Biology, Michigan State University, East Lansing, MI, United States
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, United States
| | - Jeffrey P. Townsend
- Department of Biostatistics, Yale School of Public Health, New Haven, CT, United States
- Department of Ecology and Evolutionary Biology, Program in Microbiology, and Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT, United States
| | - Oded Yarden
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
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13
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Francisco CS, McDonald BA, Palma-Guerrero J. A transcription factor and a phosphatase regulate temperature-dependent morphogenesis in the fungal plant pathogen Zymoseptoria tritici. Fungal Genet Biol 2023; 167:103811. [PMID: 37196910 DOI: 10.1016/j.fgb.2023.103811] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 04/26/2023] [Accepted: 05/10/2023] [Indexed: 05/19/2023]
Abstract
Naturally fluctuating temperatures provide a constant environmental stress that requires adaptation. Some fungal pathogens respond to heat stress by producing new morphotypes that maximize their overall fitness. The fungal wheat pathogen Zymoseptoria tritici responds to heat stress by switching from its yeast-like blastospore form to hyphae or chlamydospores. The regulatory mechanisms underlying this switch are unknown. Here, we demonstrate that a differential heat stress response is ubiquitous in Z. tritici populations around the world. We used QTL mapping to identify a single locus associated with the temperature-dependent morphogenesis and we found two genes, the transcription factor ZtMsr1 and the protein phosphatase ZtYvh1, regulating this mechanism. We find that ZtMsr1 regulates repression of hyphal growth and induces chlamydospore formation whereas ZtYvh1 is required for hyphal growth. We next showed that chlamydospore formation is a response to the intracellular osmotic stress generated by the heat stress. This intracellular stress stimulates the cell wall integrity (CWI) and high-osmolarity glycerol (HOG) MAPK pathways resulting in hyphal growth. If cell wall integrity is compromised, however, ZtMsr1 represses the hyphal development program and may induce the chlamydospore-inducing genes as a stress-response survival strategy. Taken together, these results suggest a novel mechanism through which morphological transitions are orchestrated in Z. tritici - a mechanism that may also be present in other pleomorphic fungi.
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Affiliation(s)
| | - Bruce A McDonald
- Plant Pathology Group, Institute of Integrative Biology, 8092 ETH Zürich, Switzerland
| | - Javier Palma-Guerrero
- Plant Pathology Group, Institute of Integrative Biology, 8092 ETH Zürich, Switzerland.
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14
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Langlands-Perry C, Pitarch A, Lapalu N, Cuenin M, Bergez C, Noly A, Amezrou R, Gélisse S, Barrachina C, Parrinello H, Suffert F, Valade R, Marcel TC. Quantitative and qualitative plant-pathogen interactions call upon similar pathogenicity genes with a spectrum of effects. FRONTIERS IN PLANT SCIENCE 2023; 14:1128546. [PMID: 37235026 PMCID: PMC10206311 DOI: 10.3389/fpls.2023.1128546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 04/19/2023] [Indexed: 05/28/2023]
Abstract
Septoria leaf blotch is a foliar wheat disease controlled by a combination of plant genetic resistances and fungicides use. R-gene-based qualitative resistance durability is limited due to gene-for-gene interactions with fungal avirulence (Avr) genes. Quantitative resistance is considered more durable but the mechanisms involved are not well documented. We hypothesize that genes involved in quantitative and qualitative plant-pathogen interactions are similar. A bi-parental population of Zymoseptoria tritici was inoculated on wheat cultivar 'Renan' and a linkage analysis performed to map QTL. Three pathogenicity QTL, Qzt-I05-1, Qzt-I05-6 and Qzt-I07-13, were mapped on chromosomes 1, 6 and 13 in Z. tritici, and a candidate pathogenicity gene on chromosome 6 was selected based on its effector-like characteristics. The candidate gene was cloned by Agrobacterium tumefaciens-mediated transformation, and a pathology test assessed the effect of the mutant strains on 'Renan'. This gene was demonstrated to be involved in quantitative pathogenicity. By cloning a newly annotated quantitative-effect gene in Z. tritici that is effector-like, we demonstrated that genes underlying pathogenicity QTL can be similar to Avr genes. This opens up the previously probed possibility that 'gene-for-gene' underlies not only qualitative but also quantitative plant-pathogen interactions in this pathosystem.
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Affiliation(s)
- Camilla Langlands-Perry
- Université Paris-Saclay, INRAE, UR BIOGER, Palaiseau, France
- ARVALIS Institut du Végétal, Boigneville, France
| | - Anaïs Pitarch
- Université Paris-Saclay, INRAE, UR BIOGER, Palaiseau, France
| | - Nicolas Lapalu
- Université Paris-Saclay, INRAE, UR BIOGER, Palaiseau, France
| | - Murielle Cuenin
- Université Paris-Saclay, INRAE, UR BIOGER, Palaiseau, France
| | | | - Alicia Noly
- Université Paris-Saclay, INRAE, UR BIOGER, Palaiseau, France
| | - Reda Amezrou
- Université Paris-Saclay, INRAE, UR BIOGER, Palaiseau, France
| | | | - Célia Barrachina
- MGX-Montpellier GenomiX, Univ. Montpellier, CNRS, INSERM, Montpellier, France
| | - Hugues Parrinello
- MGX-Montpellier GenomiX, Univ. Montpellier, CNRS, INSERM, Montpellier, France
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15
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Meile L, Garrido-Arandia M, Bernasconi Z, Peter J, Schneller A, Bernasconi A, Alassimone J, McDonald BA, Sánchez-Vallet A. Natural variation in Avr3D1 from Zymoseptoria sp. contributes to quantitative gene-for-gene resistance and to host specificity. THE NEW PHYTOLOGIST 2023; 238:1562-1577. [PMID: 36529883 DOI: 10.1111/nph.18690] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 12/06/2022] [Indexed: 06/17/2023]
Abstract
Successful host colonization by plant pathogens requires the circumvention of host defense responses, frequently through sequence modifications in secreted pathogen proteins known as avirulence factors (Avrs). Although Avr sequences are often polymorphic, the contribution of these polymorphisms to virulence diversity in natural pathogen populations remains largely unexplored. We used molecular genetic tools to determine how natural sequence polymorphisms of the avirulence factor Avr3D1 in the wheat pathogen Zymoseptoria tritici contributed to adaptive changes in virulence. We showed that there is a continuous distribution in the magnitude of resistance triggered by different Avr3D1 isoforms and demonstrated that natural variation in an Avr gene can lead to a quantitative resistance phenotype. We further showed that homologues of Avr3D1 in two nonpathogenic sister species of Z. tritici are recognized by some wheat cultivars, suggesting that Avr-R gene-for-gene interactions can contribute to nonhost resistance. We suggest that the mechanisms underlying host range, qualitative resistance, and quantitative resistance are not exclusive.
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Affiliation(s)
- Lukas Meile
- Plant Pathology, Institute of Integrative Biology, ETH Zurich, Universitätstrasse 2, Zurich, 8092, Switzerland
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), 28223, Pozuelo de Alarcón, Madrid, Spain
| | - María Garrido-Arandia
- Plant Pathology, Institute of Integrative Biology, ETH Zurich, Universitätstrasse 2, Zurich, 8092, Switzerland
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), 28223, Pozuelo de Alarcón, Madrid, Spain
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid (UPM), 28040, Madrid, Spain
| | - Zoe Bernasconi
- Plant Pathology, Institute of Integrative Biology, ETH Zurich, Universitätstrasse 2, Zurich, 8092, Switzerland
| | - Jules Peter
- Plant Pathology, Institute of Integrative Biology, ETH Zurich, Universitätstrasse 2, Zurich, 8092, Switzerland
| | - Alissa Schneller
- Plant Pathology, Institute of Integrative Biology, ETH Zurich, Universitätstrasse 2, Zurich, 8092, Switzerland
| | - Alessio Bernasconi
- Plant Pathology, Institute of Integrative Biology, ETH Zurich, Universitätstrasse 2, Zurich, 8092, Switzerland
| | - Julien Alassimone
- Plant Pathology, Institute of Integrative Biology, ETH Zurich, Universitätstrasse 2, Zurich, 8092, Switzerland
| | - Bruce A McDonald
- Plant Pathology, Institute of Integrative Biology, ETH Zurich, Universitätstrasse 2, Zurich, 8092, Switzerland
| | - Andrea Sánchez-Vallet
- Plant Pathology, Institute of Integrative Biology, ETH Zurich, Universitätstrasse 2, Zurich, 8092, Switzerland
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), 28223, Pozuelo de Alarcón, Madrid, Spain
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16
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Gupta PK, Vasistha NK, Singh S, Joshi AK. Genetics and breeding for resistance against four leaf spot diseases in wheat ( Triticum aestivum L.). FRONTIERS IN PLANT SCIENCE 2023; 14:1023824. [PMID: 37063191 PMCID: PMC10096043 DOI: 10.3389/fpls.2023.1023824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Accepted: 02/28/2023] [Indexed: 06/19/2023]
Abstract
In wheat, major yield losses are caused by a variety of diseases including rusts, spike diseases, leaf spot and root diseases. The genetics of resistance against all these diseases have been studied in great detail and utilized for breeding resistant cultivars. The resistance against leaf spot diseases caused by each individual necrotroph/hemi-biotroph involves a complex system involving resistance (R) genes, sensitivity (S) genes, small secreted protein (SSP) genes and quantitative resistance loci (QRLs). This review deals with resistance for the following four-leaf spot diseases: (i) Septoria nodorum blotch (SNB) caused by Parastagonospora nodorum; (ii) Tan spot (TS) caused by Pyrenophora tritici-repentis; (iii) Spot blotch (SB) caused by Bipolaris sorokiniana and (iv) Septoria tritici blotch (STB) caused by Zymoseptoria tritici.
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Affiliation(s)
- Pushpendra Kumar Gupta
- Department of Genetics and Plant Breeding, Chaudhary Charan Singh University, Meerut, India
- Murdoch’s Centre for Crop and Food Innovation, Murdoch University, Murdoch, WA, Australia
- Borlaug Institute for South Asia (BISA), National Agricultural Science Complex (NASC), Dev Prakash Shastri (DPS) Marg, New Delhi, India
| | - Neeraj Kumar Vasistha
- Department of Genetics and Plant Breeding, Chaudhary Charan Singh University, Meerut, India
- Department of Genetics-Plant Breeding and Biotechnology, Dr Khem Singh Gill, Akal College of Agriculture, Eternal University, Baru Sahib, Sirmour, India
| | - Sahadev Singh
- Department of Genetics and Plant Breeding, Chaudhary Charan Singh University, Meerut, India
| | - Arun Kumar Joshi
- Borlaug Institute for South Asia (BISA), National Agricultural Science Complex (NASC), Dev Prakash Shastri (DPS) Marg, New Delhi, India
- The International Maize and Wheat Improvement Center (CIMMYT), National Agricultural Science Complex (NASC), Dev Prakash Shastri (DPS) Marg, New Delhi, India
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17
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Sierra-Patev S, Min B, Naranjo-Ortiz M, Looney B, Konkel Z, Slot JC, Sakamoto Y, Steenwyk JL, Rokas A, Carro J, Camarero S, Ferreira P, Molpeceres G, Ruiz-Dueñas FJ, Serrano A, Henrissat B, Drula E, Hughes KW, Mata JL, Ishikawa NK, Vargas-Isla R, Ushijima S, Smith CA, Donoghue J, Ahrendt S, Andreopoulos W, He G, LaButti K, Lipzen A, Ng V, Riley R, Sandor L, Barry K, Martínez AT, Xiao Y, Gibbons JG, Terashima K, Grigoriev IV, Hibbett D. A global phylogenomic analysis of the shiitake genus Lentinula. Proc Natl Acad Sci U S A 2023; 120:e2214076120. [PMID: 36848567 PMCID: PMC10013852 DOI: 10.1073/pnas.2214076120] [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: 08/20/2022] [Accepted: 12/22/2022] [Indexed: 03/01/2023] Open
Abstract
Lentinula is a broadly distributed group of fungi that contains the cultivated shiitake mushroom, L. edodes. We sequenced 24 genomes representing eight described species and several unnamed lineages of Lentinula from 15 countries on four continents. Lentinula comprises four major clades that arose in the Oligocene, three in the Americas and one in Asia-Australasia. To expand sampling of shiitake mushrooms, we assembled 60 genomes of L. edodes from China that were previously published as raw Illumina reads and added them to our dataset. Lentinula edodes sensu lato (s. lat.) contains three lineages that may warrant recognition as species, one including a single isolate from Nepal that is the sister group to the rest of L. edodes s. lat., a second with 20 cultivars and 12 wild isolates from China, Japan, Korea, and the Russian Far East, and a third with 28 wild isolates from China, Thailand, and Vietnam. Two additional lineages in China have arisen by hybridization among the second and third groups. Genes encoding cysteine sulfoxide lyase (lecsl) and γ-glutamyl transpeptidase (leggt), which are implicated in biosynthesis of the organosulfur flavor compound lenthionine, have diversified in Lentinula. Paralogs of both genes that are unique to Lentinula (lecsl 3 and leggt 5b) are coordinately up-regulated in fruiting bodies of L. edodes. The pangenome of L. edodes s. lat. contains 20,308 groups of orthologous genes, but only 6,438 orthogroups (32%) are shared among all strains, whereas 3,444 orthogroups (17%) are found only in wild populations, which should be targeted for conservation.
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Affiliation(s)
| | - Byoungnam Min
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA94720
| | | | - Brian Looney
- Biology Department, Clark University, Worcester, MA01610
| | - Zachary Konkel
- Department of Plant Pathology, Ohio State University, Columbus, OH43210
| | - Jason C. Slot
- Department of Plant Pathology, Ohio State University, Columbus, OH43210
| | - Yuichi Sakamoto
- Iwate Biotechnology Research Center, Kitakami, Iwate024-0003, Japan
| | - Jacob L. Steenwyk
- Department of Biological Sciences and Evolutionary Studies Initiative, Vanderbilt University, Nashville, TN37235
| | - Antonis Rokas
- Department of Biological Sciences and Evolutionary Studies Initiative, Vanderbilt University, Nashville, TN37235
| | - Juan Carro
- Centro de Investigaciones Biológicas “Margarita Salas,” Consejo Superior de Investigaciones Científicas, MadridE-28040, Spain
| | - Susana Camarero
- Centro de Investigaciones Biológicas “Margarita Salas,” Consejo Superior de Investigaciones Científicas, MadridE-28040, Spain
| | - Patricia Ferreira
- Department of Biochemistry and Molecular and Cellular Biology, University of Zaragoza, 50009Zaragoza, Spain
- Institute of Biocomputation and Physics of Complex Systems, University of Zaragoza,50018Zaragoza, Spain
| | - Gonzalo Molpeceres
- Centro de Investigaciones Biológicas “Margarita Salas,” Consejo Superior de Investigaciones Científicas, MadridE-28040, Spain
| | - Francisco J. Ruiz-Dueñas
- Centro de Investigaciones Biológicas “Margarita Salas,” Consejo Superior de Investigaciones Científicas, MadridE-28040, Spain
| | - Ana Serrano
- Centro de Investigaciones Biológicas “Margarita Salas,” Consejo Superior de Investigaciones Científicas, MadridE-28040, Spain
| | - Bernard Henrissat
- DTU Bioengineering, Technical University of Denmark2800, Kgs. Lyngby, Denmark
- Department of Biological Sciences, King Abdulaziz University, Jeddah21589, Saudi Arabia
| | - Elodie Drula
- Architecture et Fonction des Macromolécules Biologiques, CNRS, Université13288, Marseille, France
- INRAE, UMR 1163, Biodiversité et Biotechnologie Fongiques13009, Marseille, France
| | - Karen W. Hughes
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN37996
| | - Juan L. Mata
- Department of Biology, University of South Alabama, Mobile, AL36688
| | - Noemia Kazue Ishikawa
- Coordenação de Biodiversidade, Instituto Nacional de Pesquisas da Amazônia, Petrópolis, ManausAM 69067-375, Brazil
| | - Ruby Vargas-Isla
- Coordenação de Biodiversidade, Instituto Nacional de Pesquisas da Amazônia, Petrópolis, ManausAM 69067-375, Brazil
| | - Shuji Ushijima
- The Tottori Mycological Institute, Japan Kinoko Research Center Foundation, Tottori689-1125, Japan
| | - Chris A. Smith
- Manaaki Whenua - Landcare Research, Auckland1072, New Zealand
| | - John Donoghue
- Northwest Mycological Consultants, Corvallis, OR97330
| | - Steven Ahrendt
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA94720
| | - William Andreopoulos
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA94720
| | - Guifen He
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA94720
| | - Kurt LaButti
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA94720
| | - Anna Lipzen
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA94720
| | - Vivian Ng
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA94720
| | - Robert Riley
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA94720
| | - Laura Sandor
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA94720
| | - Kerrie Barry
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA94720
| | - Angel T. Martínez
- Centro de Investigaciones Biológicas “Margarita Salas,” Consejo Superior de Investigaciones Científicas, MadridE-28040, Spain
| | - Yang Xiao
- Institute of Applied Mycology, Huazhong Agricultural University, Wuhan, Hubei430070, China
| | - John G. Gibbons
- Department of Food Science, University of Massachusetts, Amherst, MA01003
| | - Kazuhisa Terashima
- The Tottori Mycological Institute, Japan Kinoko Research Center Foundation, Tottori689-1125, Japan
| | - Igor V. Grigoriev
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA94720
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA94720
| | - David Hibbett
- Biology Department, Clark University, Worcester, MA01610
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18
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Chen H, King R, Smith D, Bayon C, Ashfield T, Torriani S, Kanyuka K, Hammond-Kosack K, Bieri S, Rudd J. Combined pangenomics and transcriptomics reveals core and redundant virulence processes in a rapidly evolving fungal plant pathogen. BMC Biol 2023; 21:24. [PMID: 36747219 PMCID: PMC9903594 DOI: 10.1186/s12915-023-01520-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 01/19/2023] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Studying genomic variation in rapidly evolving pathogens potentially enables identification of genes supporting their "core biology", being present, functional and expressed by all strains or "flexible biology", varying between strains. Genes supporting flexible biology may be considered to be "accessory", whilst the "core" gene set is likely to be important for common features of a pathogen species biology, including virulence on all host genotypes. The wheat-pathogenic fungus Zymoseptoria tritici represents one of the most rapidly evolving threats to global food security and was the focus of this study. RESULTS We constructed a pangenome of 18 European field isolates, with 12 also subjected to RNAseq transcription profiling during infection. Combining this data, we predicted a "core" gene set comprising 9807 sequences which were (1) present in all isolates, (2) lacking inactivating polymorphisms and (3) expressed by all isolates. A large accessory genome, consisting of 45% of the total genes, was also defined. We classified genetic and genomic polymorphism at both chromosomal and individual gene scales. Proteins required for essential functions including virulence had lower-than average sequence variability amongst core genes. Both core and accessory genomes encoded many small, secreted candidate effector proteins that likely interact with plant immunity. Viral vector-mediated transient in planta overexpression of 88 candidates failed to identify any which induced leaf necrosis characteristic of disease. However, functional complementation of a non-pathogenic deletion mutant lacking five core genes demonstrated that full virulence was restored by re-introduction of the single gene exhibiting least sequence polymorphism and highest expression. CONCLUSIONS These data support the combined use of pangenomics and transcriptomics for defining genes which represent core, and potentially exploitable, weaknesses in rapidly evolving pathogens.
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Affiliation(s)
- Hongxin Chen
- grid.418374.d0000 0001 2227 9389Department of Protecting Crops and the Environment, Rothamsted Research, Harpenden, Herts UK ,grid.12981.330000 0001 2360 039XPresent address: School of Agriculture, Shenzhen Campus of Sun Yat-sen University, Guangming District, Shenzhen, Guangdong People’s Republic of China
| | - Robert King
- grid.418374.d0000 0001 2227 9389Department of Protecting Crops and the Environment, Rothamsted Research, Harpenden, Herts UK
| | - Dan Smith
- grid.418374.d0000 0001 2227 9389Department of Protecting Crops and the Environment, Rothamsted Research, Harpenden, Herts UK
| | - Carlos Bayon
- grid.418374.d0000 0001 2227 9389Department of Protecting Crops and the Environment, Rothamsted Research, Harpenden, Herts UK
| | - Tom Ashfield
- grid.418374.d0000 0001 2227 9389Department of Protecting Crops and the Environment, Rothamsted Research, Harpenden, Herts UK ,grid.418374.d0000 0001 2227 9389Crop Health and Protection (CHaP), Rothamsted Research, Harpenden, Herts UK
| | - Stefano Torriani
- grid.420222.40000 0001 0669 0426Syngenta Crop Protection AG, Schaffhauserstrasse 101, CH-4332 Stein, Switzerland
| | - Kostya Kanyuka
- grid.418374.d0000 0001 2227 9389Department of Protecting Crops and the Environment, Rothamsted Research, Harpenden, Herts UK ,grid.17595.3f0000 0004 0383 6532Present address: National Institute for Agricultural Botany (NIAB), 93 Lawrence Weaver Road, Cambridge, UK
| | - Kim Hammond-Kosack
- grid.418374.d0000 0001 2227 9389Department of Protecting Crops and the Environment, Rothamsted Research, Harpenden, Herts UK
| | - Stephane Bieri
- grid.420222.40000 0001 0669 0426Syngenta Crop Protection AG, Schaffhauserstrasse 101, CH-4332 Stein, Switzerland
| | - Jason Rudd
- Department of Protecting Crops and the Environment, Rothamsted Research, Harpenden, Herts, UK.
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19
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Blyth HR, Smith D, King R, Bayon C, Ashfield T, Walpole H, Venter E, Ray RV, Kanyuka K, Rudd JJ. Fungal plant pathogen "mutagenomics" reveals tagged and untagged mutations in Zymoseptoria tritici and identifies SSK2 as key morphogenesis and stress-responsive virulence factor. FRONTIERS IN PLANT SCIENCE 2023; 14:1140824. [PMID: 37206970 PMCID: PMC10190600 DOI: 10.3389/fpls.2023.1140824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 03/29/2023] [Indexed: 05/21/2023]
Abstract
"Mutagenomics" is the combination of random mutagenesis, phenotypic screening, and whole-genome re-sequencing to uncover all tagged and untagged mutations linked with phenotypic changes in an organism. In this study, we performed a mutagenomics screen on the wheat pathogenic fungus Zymoseptoria tritici for altered morphogenetic switching and stress sensitivity phenotypes using Agrobacterium-mediated "random" T-DNA mutagenesis (ATMT). Biological screening identified four mutants which were strongly reduced in virulence on wheat. Whole genome re-sequencing defined the positions of the T-DNA insertion events and revealed several unlinked mutations potentially affecting gene functions. Remarkably, two independent reduced virulence mutant strains, with similarly altered stress sensitivities and aberrant hyphal growth phenotypes, were found to have a distinct loss of function mutations in the ZtSSK2 MAPKKK gene. One mutant strain had a direct T-DNA insertion affecting the predicted protein's N-terminus, while the other possessed an unlinked frameshift mutation towards the C-terminus. We used genetic complementation to restore both strains' wild-type (WT) function (virulence, morphogenesis, and stress response). We demonstrated that ZtSSK2 has a non-redundant function with ZtSTE11 in virulence through the biochemical activation of the stress-activated HOG1 MAPK pathway. Moreover, we present data suggesting that SSK2 has a unique role in activating this pathway in response to specific stresses. Finally, dual RNAseq-based transcriptome profiling of WT and SSK2 mutant strains revealed many HOG1-dependent transcriptional changes in the fungus during early infection and suggested that the host response does not discriminate between WT and mutant strains during this early phase. Together these data define new genes implicated in the virulence of the pathogen and emphasise the importance of a whole genome sequencing step in mutagenomic discovery pipelines.
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Affiliation(s)
- Hannah R. Blyth
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, United Kingdom
| | - Dan Smith
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, United Kingdom
| | - Robert King
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, United Kingdom
| | - Carlos Bayon
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, United Kingdom
| | - Tom Ashfield
- Crop Health and Protection (CHAP), Rothamsted Research, Harpenden, United Kingdom
| | - Hannah Walpole
- Bioimaging Unit, Rothamsted Research, Harpenden, United Kingdom
| | - Eudri Venter
- Bioimaging Unit, Rothamsted Research, Harpenden, United Kingdom
| | - Rumiana V. Ray
- Division of Plant and Crop Sciences, School of Biosciences, University of Nottingham, Loughborough, United Kingdom
| | - Kostya Kanyuka
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, United Kingdom
| | - Jason J. Rudd
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, United Kingdom
- *Correspondence: Jason J. Rudd,
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Merges D, Dal Grande F, Valim H, Singh G, Schmitt I. Gene abundance linked to climate zone: Parallel evolution of gene content along elevation gradients in lichenized fungi. Front Microbiol 2023; 14:1097787. [PMID: 37032854 PMCID: PMC10073550 DOI: 10.3389/fmicb.2023.1097787] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 02/23/2023] [Indexed: 04/11/2023] Open
Abstract
Introduction Intraspecific genomic variability affects a species' adaptive potential toward climatic conditions. Variation in gene content across populations and environments may point at genomic adaptations to specific environments. The lichen symbiosis, a stable association of fungal and photobiont partners, offers an excellent system to study environmentally driven gene content variation. Many of these species have remarkable environmental tolerances, and often form populations across different climate zones. Here, we combine comparative and population genomics to assess the presence and absence of genes in high and low elevation genomes of two lichenized fungi of the genus Umbilicaria. Methods The two species have non-overlapping ranges, but occupy similar climatic niches in North America (U. phaea) and Europe (U. pustulata): high elevation populations are located in the cold temperate zone and low elevation populations in the Mediterranean zone. We assessed gene content variation along replicated elevation gradients in each of the two species, based on a total of 2050 individuals across 26 populations. Specifically, we assessed shared orthologs across species within the same climate zone, and tracked, which genes increase or decrease in abundance within populations along elevation. Results In total, we found 16 orthogroups with shared orthologous genes in genomes at low elevation and 13 at high elevation. Coverage analysis revealed one ortholog that is exclusive to genomes at low elevation. Conserved domain search revealed domains common to the protein kinase superfamily. We traced the discovered ortholog in populations along five replicated elevation gradients on both continents and found that the number of this protein kinase gene linearly declined in abundance with increasing elevation, and was absent in the highest populations. Discussion We consider the parallel loss of an ortholog in two species and in two geographic settings a rare find, and a step forward in understanding the genomic underpinnings of climatic tolerances in lichenized fungi. In addition, the tracking of gene content variation provides a widely applicable framework for retrieving biogeographical determinants of gene presence/absence patterns. Our work provides insights into gene content variation of lichenized fungi in relation to climatic gradients, suggesting a new research direction with implications for understanding evolutionary trajectories of complex symbioses in relation to climatic change.
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Affiliation(s)
- Dominik Merges
- Senckenberg Biodiversity and Climate Research Centre, Frankfurt am Main, Germany
- LOEWE Centre for Translational Biodiversity Genomics (LOEWE-TBG), Frankfurt am Main, Germany
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
- *Correspondence: Dominik Merges,
| | - Francesco Dal Grande
- Senckenberg Biodiversity and Climate Research Centre, Frankfurt am Main, Germany
- LOEWE Centre for Translational Biodiversity Genomics (LOEWE-TBG), Frankfurt am Main, Germany
- Department of Biology, University of Padova, Padua, Italy
- National Biodiversity Future Center (NBFC), Palermo, Italy
| | - Henrique Valim
- Senckenberg Biodiversity and Climate Research Centre, Frankfurt am Main, Germany
- LOEWE Centre for Translational Biodiversity Genomics (LOEWE-TBG), Frankfurt am Main, Germany
| | - Garima Singh
- Senckenberg Biodiversity and Climate Research Centre, Frankfurt am Main, Germany
- LOEWE Centre for Translational Biodiversity Genomics (LOEWE-TBG), Frankfurt am Main, Germany
- Department of Biology, University of Padova, Padua, Italy
| | - Imke Schmitt
- Senckenberg Biodiversity and Climate Research Centre, Frankfurt am Main, Germany
- LOEWE Centre for Translational Biodiversity Genomics (LOEWE-TBG), Frankfurt am Main, Germany
- Goethe University Frankfurt, Institute of Ecology, Evolution and Diversity, Frankfurt am Main, Germany
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Pan-Genomics Reveals a New Variation Pattern of Secreted Proteins in Pyricularia oryzae. J Fungi (Basel) 2022; 8:jof8121238. [PMID: 36547571 PMCID: PMC9785059 DOI: 10.3390/jof8121238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 11/19/2022] [Accepted: 11/20/2022] [Indexed: 11/24/2022] Open
Abstract
(1) Background: Pyricularia oryzae, the causal agent of rice blast disease, is one of the major rice pathogens. The complex population structure of P. oryzae facilitates the rapid virulence variations, which make the blast disease a serious challenge for global food security. There is a large body of existing genomics research on P. oryzae, however the population structure at the pan-genome level is not clear, and the mechanism of genetic divergence and virulence variations of different sub-populations is also unknown. (2) Methods: Based on the genome data published in the NCBI, we constructed a pan-genome database of P. oryzae, which consisted of 156 strains (117 isolated from rice and 39 isolated from other hosts). (3) Results: The pan-genome contained a total of 24,100 genes (12,005 novel genes absent in the reference genome 70-15), including 16,911 (~70%) core genes (population frequency ≥95%) and 1378 (~5%) strain-specific genes (population frequency ≤5%). Gene presence-absence variation (PAV) based clustering analysis of the population structure of P. oryzae revealed four subgroups (three from rice and one from other hosts). Interestingly, the cloned avirulence genes and conventional secreted proteins (SPs, with signal peptides) were enriched in the high-frequency regions and significantly associated with transposable elements (TEs), while the unconventional SPs (without signal peptides) were enriched in the low-frequency regions and not associated significantly with TEs. This pan-genome will expand the breadth and depth of the rice blast fungus reference genome, and also serve as a new blueprint for scientists to further study the pathogenic mechanism and virulence variation of the rice blast fungus.
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22
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Fraser CJ, Whitehall SK. Heterochromatin in the fungal plant pathogen, Zymoseptoria tritici: Control of transposable elements, genome plasticity and virulence. Front Genet 2022; 13:1058741. [DOI: 10.3389/fgene.2022.1058741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 11/04/2022] [Indexed: 11/22/2022] Open
Abstract
Heterochromatin is a repressive chromatin state that plays key roles in the functional organisation of eukaryotic genomes. In fungal plant pathogens, effector genes that are required for host colonization tend to be associated with heterochromatic regions of the genome that are enriched with transposable elements. It has been proposed that the heterochromatin environment silences effector genes in the absence of host and dynamic chromatin remodelling facilitates their expression during infection. Here we discuss this model in the context of the key wheat pathogen, Zymoseptoria tritici. We cover progress in understanding the deposition and recognition of heterochromatic histone post translational modifications in Z. tritici and the role that heterochromatin plays in control of genome plasticity and virulence.
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23
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Guo Y, Betzen B, Salcedo A, He F, Bowden RL, Fellers JP, Jordan KW, Akhunova A, Rouse MN, Szabo LJ, Akhunov E. Population genomics of Puccinia graminis f.sp. tritici highlights the role of admixture in the origin of virulent wheat rust races. Nat Commun 2022; 13:6287. [PMID: 36271077 PMCID: PMC9587050 DOI: 10.1038/s41467-022-34050-w] [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: 03/31/2022] [Accepted: 10/12/2022] [Indexed: 12/25/2022] Open
Abstract
Puccinia graminis f.sp. tritici (Pgt) causes stem rust disease in wheat that can result in severe yield losses. The factors driving the evolution of its virulence and adaptation remain poorly characterized. We utilize long-read sequencing to develop a haplotype-resolved genome assembly of a U.S. isolate of Pgt. Using Pgt haplotypes as a reference, we characterize the structural variants (SVs) and single nucleotide polymorphisms in a diverse panel of isolates. SVs impact the repertoire of predicted effectors, secreted proteins involved in host-pathogen interaction, and show evidence of purifying selection. By analyzing global and local genomic ancestry we demonstrate that the origin of 8 out of 12 Pgt clades is linked with either somatic hybridization or sexual recombination between the diverged donor populations. Our study shows that SVs and admixture events appear to play an important role in broadening Pgt virulence and the origin of highly virulent races, creating a resource for studying the evolution of Pgt virulence and preventing future epidemic outbreaks.
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Affiliation(s)
- Yuanwen Guo
- grid.36567.310000 0001 0737 1259Department of Plant Pathology, Kansas State University, Manhattan, KS USA
| | - Bliss Betzen
- grid.36567.310000 0001 0737 1259Department of Plant Pathology, Kansas State University, Manhattan, KS USA ,grid.36567.310000 0001 0737 1259Present Address: USDA-APHIS-PPQ Field Operations, Kansas State University, Manhattan, KS USA
| | - Andres Salcedo
- grid.36567.310000 0001 0737 1259Department of Plant Pathology, Kansas State University, Manhattan, KS USA ,grid.40803.3f0000 0001 2173 6074Present Address: Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC USA
| | - Fei He
- grid.36567.310000 0001 0737 1259Department of Plant Pathology, Kansas State University, Manhattan, KS USA ,grid.9227.e0000000119573309Present Address: State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Robert L. Bowden
- grid.512831.cUSDA-ARS, Hard Winter Wheat Genetics Research Unit, Manhattan, KS USA
| | - John P. Fellers
- grid.512831.cUSDA-ARS, Hard Winter Wheat Genetics Research Unit, Manhattan, KS USA
| | - Katherine W. Jordan
- grid.36567.310000 0001 0737 1259Department of Plant Pathology, Kansas State University, Manhattan, KS USA ,grid.512831.cUSDA-ARS, Hard Winter Wheat Genetics Research Unit, Manhattan, KS USA
| | - Alina Akhunova
- grid.36567.310000 0001 0737 1259Department of Plant Pathology, Kansas State University, Manhattan, KS USA ,grid.36567.310000 0001 0737 1259Integrated Genomics Facility, Kansas State University, Manhattan, KS USA
| | - Mathew N. Rouse
- grid.512864.c0000 0000 8881 3436Department of Plant Pathology, University of Minnesota & USDA-ARS, Cereal Disease Lab, St. Paul, MN USA
| | - Les J. Szabo
- grid.512864.c0000 0000 8881 3436Department of Plant Pathology, University of Minnesota & USDA-ARS, Cereal Disease Lab, St. Paul, MN USA
| | - Eduard Akhunov
- grid.36567.310000 0001 0737 1259Department of Plant Pathology, Kansas State University, Manhattan, KS USA ,grid.36567.310000 0001 0737 1259Wheat Genetics Resource Center, Kansas State University, Manhattan, KS USA
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Ruggieri AA, Livraghi L, Lewis JJ, Evans E, Cicconardi F, Hebberecht L, Ortiz-Ruiz Y, Montgomery SH, Ghezzi A, Rodriguez-Martinez JA, Jiggins CD, McMillan WO, Counterman BA, Papa R, Van Belleghem SM. A butterfly pan-genome reveals that a large amount of structural variation underlies the evolution of chromatin accessibility. Genome Res 2022; 32:1862-1875. [PMID: 36109150 PMCID: PMC9712634 DOI: 10.1101/gr.276839.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Accepted: 09/13/2022] [Indexed: 01/16/2023]
Abstract
Despite insertions and deletions being the most common structural variants (SVs) found across genomes, not much is known about how much these SVs vary within populations and between closely related species, nor their significance in evolution. To address these questions, we characterized the evolution of indel SVs using genome assemblies of three closely related Heliconius butterfly species. Over the relatively short evolutionary timescales investigated, up to 18.0% of the genome was composed of indels between two haplotypes of an individual Heliconius charithonia butterfly and up to 62.7% included lineage-specific SVs between the genomes of the most distant species (11 Mya). Lineage-specific sequences were mostly characterized as transposable elements (TEs) inserted at random throughout the genome and their overall distribution was similarly affected by linked selection as single nucleotide substitutions. Using chromatin accessibility profiles (i.e., ATAC-seq) of head tissue in caterpillars to identify sequences with potential cis-regulatory function, we found that out of the 31,066 identified differences in chromatin accessibility between species, 30.4% were within lineage-specific SVs and 9.4% were characterized as TE insertions. These TE insertions were localized closer to gene transcription start sites than expected at random and were enriched for sites with significant resemblance to several transcription factor binding sites with known function in neuron development in Drosophila We also identified 24 TE insertions with head-specific chromatin accessibility. Our results show high rates of structural genome evolution that were previously overlooked in comparative genomic studies and suggest a high potential for structural variation to serve as raw material for adaptive evolution.
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Affiliation(s)
- Angelo A Ruggieri
- Department of Biology, University of Puerto Rico-Rio Piedras, San Juan PR 00931, Puerto Rico
| | - Luca Livraghi
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA
- Smithsonian Tropical Research Institute, Apartado 0843-03092 Panamá, Panama
| | - James J Lewis
- Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Elizabeth Evans
- Department of Biology, University of Puerto Rico-Rio Piedras, San Juan PR 00931, Puerto Rico
| | - Francesco Cicconardi
- School of Biological Sciences, Bristol University, Bristol BS8 1QU, United Kingdom
| | - Laura Hebberecht
- School of Biological Sciences, Bristol University, Bristol BS8 1QU, United Kingdom
| | - Yadira Ortiz-Ruiz
- Department of Biology, University of Puerto Rico-Rio Piedras, San Juan PR 00931, Puerto Rico
- Molecular Sciences and Research Center, University of Puerto Rico, San Juan 00926, Puerto Rico
| | - Stephen H Montgomery
- School of Biological Sciences, Bristol University, Bristol BS8 1QU, United Kingdom
| | - Alfredo Ghezzi
- Department of Biology, University of Puerto Rico-Rio Piedras, San Juan PR 00931, Puerto Rico
| | | | - Chris D Jiggins
- Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, United Kingdom
| | - W Owen McMillan
- Smithsonian Tropical Research Institute, Apartado 0843-03092 Panamá, Panama
| | - Brian A Counterman
- Department of Biological Sciences, Auburn University, Auburn, Alabama 36849, USA
| | - Riccardo Papa
- Department of Biology, University of Puerto Rico-Rio Piedras, San Juan PR 00931, Puerto Rico
- Molecular Sciences and Research Center, University of Puerto Rico, San Juan 00926, Puerto Rico
| | - Steven M Van Belleghem
- Department of Biology, University of Puerto Rico-Rio Piedras, San Juan PR 00931, Puerto Rico
- Ecology, Evolution and Conservation Biology, Biology Department, KU Leuven, 3000 Leuven, Belgium
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25
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Ogaji YO, Lee RC, Sawbridge TI, Cocks BG, Daetwyler HD, Kaur S. De Novo Long-Read Whole-Genome Assemblies and the Comparative Pan-Genome Analysis of Ascochyta Blight Pathogens Affecting Field Pea. J Fungi (Basel) 2022; 8:jof8080884. [PMID: 36012871 PMCID: PMC9410150 DOI: 10.3390/jof8080884] [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: 06/22/2022] [Revised: 08/12/2022] [Accepted: 08/15/2022] [Indexed: 11/16/2022] Open
Abstract
Ascochyta Blight (AB) is a major disease of many cool-season legumes globally. In field pea, three fungal pathogens have been identified to be responsible for this disease in Australia, namely Peyronellaea pinodes, Peyronellaea pinodella and Phoma koolunga. Limited genomic resources for these pathogens have been generated, which has hampered the implementation of effective management strategies and breeding for resistant cultivars. Using Oxford Nanopore long-read sequencing, we report the first high-quality, fully annotated, near-chromosome-level nuclear and mitochondrial genome assemblies for 18 isolates from the Australian AB complex. Comparative genome analysis was performed to elucidate the differences and similarities between species and isolates using phylogenetic relationships and functional diversity. Our data indicated that P. pinodella and P. koolunga are heterothallic, while P. pinodes is homothallic. More homology and orthologous gene clusters are shared between P. pinodes and P. pinodella compared to P. koolunga. The analysis of the repetitive DNA content showed differences in the transposable repeat composition in the genomes and their expression in the transcriptomes. Significant repeat expansion in P. koolunga’s genome was seen, with strong repeat-induced point mutation (RIP) activity being evident. Phylogenetic analysis revealed that genetic diversity can be exploited for species marker development. This study provided the much-needed genetic resources and characterization of the AB species to further drive research in key areas such as disease epidemiology and host–pathogen interactions.
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Affiliation(s)
- Yvonne O. Ogaji
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 5 Ring Road, Melbourne, VIC 3083, Australia
- School of Applied Systems Biology, La Trobe University, Melbourne, VIC 3086, Australia
| | - Robert C. Lee
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Perth, WA 6102, Australia
| | - Tim I. Sawbridge
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 5 Ring Road, Melbourne, VIC 3083, Australia
- School of Applied Systems Biology, La Trobe University, Melbourne, VIC 3086, Australia
| | - Benjamin G. Cocks
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 5 Ring Road, Melbourne, VIC 3083, Australia
- School of Applied Systems Biology, La Trobe University, Melbourne, VIC 3086, Australia
| | - Hans D. Daetwyler
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 5 Ring Road, Melbourne, VIC 3083, Australia
- School of Applied Systems Biology, La Trobe University, Melbourne, VIC 3086, Australia
| | - Sukhjiwan Kaur
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 5 Ring Road, Melbourne, VIC 3083, Australia
- Correspondence:
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26
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Dmitriev AA, Pushkova EN, Melnikova NV. Plant Genome Sequencing: Modern Technologies and Novel Opportunities for Breeding. Mol Biol 2022. [DOI: 10.1134/s0026893322040045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Li W, Liu J, Zhang H, Liu Z, Wang Y, Xing L, He Q, Du H. Plant pan-genomics: recent advances, new challenges, and roads ahead. J Genet Genomics 2022; 49:833-846. [PMID: 35750315 DOI: 10.1016/j.jgg.2022.06.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 06/09/2022] [Accepted: 06/10/2022] [Indexed: 10/18/2022]
Abstract
Pan-genomics can encompass most of the genetic diversity of a species or population and has proved to be a powerful tool for studying genomic evolution and the origin and domestication of species, and for providing information for plant improvement. Plant genomics has greatly progressed because of improvements in sequencing technologies and the rapid reduction of sequencing costs. Nevertheless, pan-genomics still presents many challenges, including computationally intensive assembly methods, high costs with large numbers of samples, ineffective integration of big data, and difficulty in applying it to downstream multi-omics analysis and breeding research. In this review, we summarize the definition and recent achievements of plant pan-genomics, computational technologies used for pan-genome construction, and the applications of pan-genomes in plant genomics and molecular breeding. We also discuss challenges and perspectives for future pan-genomics studies and provide a detailed pipeline for sample selection, genome assembly and annotation, structural variation identification, and construction and application of graph-based pan-genomes. The aim is to provide important guidance for plant pan-genome research and a better understanding of the genetic basis of genome evolution, crop domestication, and phenotypic diversity for future studies.
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Affiliation(s)
- Wei Li
- School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, Hebei 071000, China
| | - Jianan Liu
- School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, Hebei 071000, China
| | - Hongyu Zhang
- School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, Hebei 071000, China
| | - Ze Liu
- School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, Hebei 071000, China
| | - Yu Wang
- School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, Hebei 071000, China
| | - Longsheng Xing
- School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, Hebei 071000, China
| | - Qiang He
- School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, Hebei 071000, China
| | - Huilong Du
- School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, Hebei 071000, China.
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28
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McDonald BA, Suffert F, Bernasconi A, Mikaberidze A. How large and diverse are field populations of fungal plant pathogens? The case of
Zymoseptoria tritici. Evol Appl 2022; 15:1360-1373. [PMID: 36187182 PMCID: PMC9488677 DOI: 10.1111/eva.13434] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 05/28/2022] [Accepted: 06/06/2022] [Indexed: 12/02/2022] Open
Abstract
Pathogen populations differ in the amount of genetic diversity they contain. Populations carrying higher genetic diversity are thought to have a greater evolutionary potential than populations carrying less diversity. We used published studies to estimate the range of values associated with two critical components of genetic diversity, the number of unique pathogen genotypes and the number of spores produced during an epidemic, for the septoria tritici blotch pathogen Zymoseptoria tritici. We found that wheat fields experiencing typical levels of infection are likely to carry between 3.1 and 14.0 million pathogen genotypes per hectare and produce at least 2.1–9.9 trillion pycnidiospores per hectare. Given the experimentally derived mutation rate of 3 × 10−10 substitutions per site per cell division, we estimate that between 27 and 126 million pathogen spores carrying adaptive mutations to counteract fungicides and resistant cultivars will be produced per hectare during a growing season. This suggests that most of the adaptive mutations that have been observed in Z. tritici populations can emerge through local selection from standing genetic variation that already exists within each field. The consequences of these findings for disease management strategies are discussed.
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Affiliation(s)
- Bruce A. McDonald
- Plant Pathology Group Institute of Integrative Biology ETH Zurich Zurich Switzerland
| | - Frederic Suffert
- Université Paris‐Saclay INRAE, UR BIOGER Thiverval‐Grignon France
| | - Alessio Bernasconi
- Plant Pathology Group Institute of Integrative Biology ETH Zurich Zurich Switzerland
| | - Alexey Mikaberidze
- School of Agriculture Policy and Development, University of Reading Whiteknights Reading UK
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Padmathilake KRE, Fernando WGD. Leptosphaeria maculans-Brassica napus Battle: A Comparison of Incompatible vs. Compatible Interactions Using Dual RNASeq. Int J Mol Sci 2022; 23:ijms23073964. [PMID: 35409323 PMCID: PMC8999614 DOI: 10.3390/ijms23073964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 03/28/2022] [Accepted: 03/30/2022] [Indexed: 02/05/2023] Open
Abstract
Leptosphaeria maculans causes blackleg disease, which is one of the most destructive diseases of canola (Brassica napus L.). Due to the erosion of the current resistance in B. napus, it is pivotal to introduce new resistant genotypes to the growers. This study evaluated the potential of Rlm7 gene as resistance to its corresponding avirulence AvrLm7 gene is abundant. The Rlm7 line was inoculated with L. maculans isolate with AvrLm7; UMAvr7; and the CRISPR/Cas9 knockout AvrLm7 mutant, umavr7, of the same isolate to cause incompatible and compatible interactions, respectively. Dual RNA-seq showed differential gene expressions in both interactions. High expressions of virulence-related pathogen genes-CAZymes, merops, and effector proteins after 7-dpi in compatible interactions but not in incompatible interaction—confirmed that the pathogen was actively virulent only in compatible interactions. Salicyclic and jasmonic acid biosynthesis and signaling-related genes, defense-related PR1 gene (GSBRNA2T00150001001), and GSBRNA2T00068522001 in the NLR gene family were upregulated starting as early as 1- and 3-dpi in the incompatible interaction and the high upregulation of those genes after 7-dpi in compatible interactions confirmed the early recognition of the pathogen by the host and control it by early activation of host defense mechanisms in the incompatible interaction.
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30
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Pangenomics in Microbial and Crop Research: Progress, Applications, and Perspectives. Genes (Basel) 2022; 13:genes13040598. [PMID: 35456404 PMCID: PMC9031676 DOI: 10.3390/genes13040598] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 03/16/2022] [Accepted: 03/25/2022] [Indexed: 01/25/2023] Open
Abstract
Advances in sequencing technologies and bioinformatics tools have fueled a renewed interest in whole genome sequencing efforts in many organisms. The growing availability of multiple genome sequences has advanced our understanding of the within-species diversity, in the form of a pangenome. Pangenomics has opened new avenues for future research such as allowing dissection of complex molecular mechanisms and increased confidence in genome mapping. To comprehensively capture the genetic diversity for improving plant performance, the pangenome concept is further extended from species to genus level by the inclusion of wild species, constituting a super-pangenome. Characterization of pangenome has implications for both basic and applied research. The concept of pangenome has transformed the way biological questions are addressed. From understanding evolution and adaptation to elucidating host–pathogen interactions, finding novel genes or breeding targets to aid crop improvement to design effective vaccines for human prophylaxis, the increasing availability of the pangenome has revolutionized several aspects of biological research. The future availability of high-resolution pangenomes based on reference-level near-complete genome assemblies would greatly improve our ability to address complex biological problems.
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31
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Differential regulation and production of secondary metabolites among isolates of the fungal wheat pathogen Zymoseptoria tritici. Appl Environ Microbiol 2022; 88:e0229621. [PMID: 35108092 PMCID: PMC8939313 DOI: 10.1128/aem.02296-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The genome of the wheat pathogenic fungus, Zymoseptoria tritici, represents extensive presence-absence variation in gene content. Here, we addressed variation in biosynthetic gene clusters (BGCs) content and biochemical profiles among three isolates. We analysed secondary metabolite properties based on genome, transcriptome and metabolome data. The isolates represent highly distinct genome architecture, but harbor similar repertoire of BGCs. Expression profiles for most BGCs show comparable patterns of regulation among the isolates, suggesting a conserved "biochemical infection program". For all three isolates, we observed a strong up-regulation of a putative abscisic acid (ABA) gene cluster during biotrophic host colonization, indicating that Z. tritici potentially interfere with host defenses by the biosynthesis of this phytohormone. Further, during in vitro growth the isolates show similar metabolomes congruent with the predicted BGC content. We assessed if secondary metabolite production is regulated by histone methylation using a mutant impaired in formation of facultative heterochromatin (H3K27me3). In contrast to other ascomycete fungi, chromatin modifications play a less prominent role in regulation of secondary metabolites. In summary, we show that Z. tritici has a conserved program of secondary metabolite production contrasting the immense variation in effector expression, some of these metabolites might play a key role during host colonization. Importance Zymoseptoria tritici is one of the most devastating pathogens of wheat. So far the molecular determinants of virulence and their regulation are poorly understood. Previous studies have focused on proteinasous virulence factors and their extensive diversity. In this study, we focus on secondary metabolites produced by Z. tritici. Using a comparative framework, we here characterize core and non-core metabolites produced by Z. tritici by combining genome, transcriptome and metabolome datasets. Our findings indicate highly conserved biochemical profiles contrasting genetic and phenotypic diversity of the field isolates investigated here. This discovery has relevance for future crop protection strategies.
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32
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Pronozin AY, Bragina MK, Salina EA. Crop pangenomes. Vavilovskii Zhurnal Genet Selektsii 2021; 25:57-63. [PMID: 34901703 PMCID: PMC8629360 DOI: 10.18699/vj21.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 12/27/2020] [Accepted: 01/03/2021] [Indexed: 11/19/2022] Open
Abstract
Progress in genome sequencing, assembly and analysis allows for a deeper study of agricultural plants' chromosome structures, gene identification and annotation. The published genomes of agricultural plants proved to be a valuable tool for studing gene functions and for marker-assisted and genomic selection. However, large structural genome changes, including gene copy number variations (CNVs) and gene presence/absence variations (PAVs), prevail in crops. These genomic variations play an important role in the functional set of genes and the gene composition in individuals of the same species and provide the genetic determination of the agronomically important crops properties. A high degree of genomic variation observed indicates that single reference genomes do not represent the diversity within a species, leading to the pangenome concept. The pangenome represents information about all genes in a taxon: those that are common to all taxon members and those that are variable and are partially or completely specific for particular individuals. Pangenome sequencing and analysis technologies provide a large-scale study of genomic variation and resources for an evolutionary research, functional genomics and crop breeding. This review provides an analysis of agricultural plants' pangenome studies. Pangenome structural features, methods and programs for bioinformatic analysis of pangenomic data are described.
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Affiliation(s)
- A Yu Pronozin
- Institute of Cytology and Genetics of Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - M K Bragina
- Institute of Cytology and Genetics of Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia Kurchatov Genomic Center of the Institute of Cytology and Genetics of Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - E A Salina
- Institute of Cytology and Genetics of Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia Kurchatov Genomic Center of the Institute of Cytology and Genetics of Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
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33
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Chepsergon J, Motaung TE, Moleleki LN. "Core" RxLR effectors in phytopathogenic oomycetes: A promising way to breeding for durable resistance in plants? Virulence 2021; 12:1921-1935. [PMID: 34304703 PMCID: PMC8516161 DOI: 10.1080/21505594.2021.1948277] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 06/11/2021] [Accepted: 06/18/2021] [Indexed: 12/30/2022] Open
Abstract
Phytopathogenic oomycetes are known to successfully infect their hosts due to their ability to secrete effector proteins. Of interest to many researchers are effectors with the N-terminal RxLR motif (Arginine-any amino acid-Leucine-Arginine). Owing to advances in genome sequencing, we can now comprehend the high level of diversity among oomycete effectors, and similarly, their conservation within and among species referred to here as "core" RxLR effectors (CREs). Currently, there is a considerable number of CREs that have been identified in oomycetes. Functional characterization of these CREs propose their virulence role with the potential of targeting central cellular processes that are conserved across diverse plant species. We reason that effectors that are highly conserved and recognized by the host, could be harnessed in engineering plants for durable as well as broad-spectrum resistance.
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Affiliation(s)
- Jane Chepsergon
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, Gauteng, South Africa
| | - Thabiso E. Motaung
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, Gauteng, South Africa
| | - Lucy Novungayo Moleleki
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, Gauteng, South Africa
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34
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Treindl AD, Stapley J, Winter DJ, Cox MP, Leuchtmann A. Chromosome-level genomes provide insights into genome evolution, organization and size in Epichloe fungi. Genomics 2021; 113:4267-4275. [PMID: 34774981 DOI: 10.1016/j.ygeno.2021.11.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 10/21/2021] [Accepted: 11/08/2021] [Indexed: 01/10/2023]
Abstract
Epichloe fungi are endophytes of cool season grasses, both wild species and commercial cultivars, where they may exhibit mutualistic or pathogenic lifestyles. The Epichloe-grass symbiosis is of great interest to agricultural research for the fungal bioprotective properties conferred to host grasses but also serves as an ideal system to study the evolution of fungal plant-pathogens in natural environments. Here, we assembled and annotated gapless chromosome-level genomes of two pathogenic Epichloe sibling species. Both genomes have a bipartite genome organization, with blocks of highly syntenic gene-rich regions separated by blocks of AT-rich DNA. The AT-rich regions show an extensive signature of RIP (repeat-induced point mutation) and the expansion of this compartment accounts for the large difference in genome size between the two species. This study reveals how the rapid evolution of repeat structure can drive divergence between closely related taxa and highlights the evolutionary role of dynamic compartments in fungal genomes.
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Affiliation(s)
- Artemis D Treindl
- Plant Ecological Genetics Group, Institute of Integrative Biology, ETH Zurich, 8092 Zurich, Switzerland.
| | - Jessica Stapley
- Plant Ecological Genetics Group, Institute of Integrative Biology, ETH Zurich, 8092 Zurich, Switzerland
| | - David J Winter
- Statistics and Bioinformatics Group, School of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | - Murray P Cox
- Statistics and Bioinformatics Group, School of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | - Adrian Leuchtmann
- Plant Ecological Genetics Group, Institute of Integrative Biology, ETH Zurich, 8092 Zurich, Switzerland
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35
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Epigenetic modifications affect the rate of spontaneous mutations in a pathogenic fungus. Nat Commun 2021; 12:5869. [PMID: 34620872 PMCID: PMC8497519 DOI: 10.1038/s41467-021-26108-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 09/17/2021] [Indexed: 12/17/2022] Open
Abstract
Mutations are the source of genetic variation and the substrate for evolution. Genome-wide mutation rates appear to be affected by selection and are probably adaptive. Mutation rates are also known to vary along genomes, possibly in response to epigenetic modifications, but causality is only assumed. In this study we determine the direct impact of epigenetic modifications and temperature stress on mitotic mutation rates in a fungal pathogen using a mutation accumulation approach. Deletion mutants lacking epigenetic modifications confirm that histone mark H3K27me3 increases whereas H3K9me3 decreases the mutation rate. Furthermore, cytosine methylation in transposable elements (TE) increases the mutation rate 15-fold resulting in significantly less TE mobilization. Also accessory chromosomes have significantly higher mutation rates. Finally, we find that temperature stress substantially elevates the mutation rate. Taken together, we find that epigenetic modifications and environmental conditions modify the rate and the location of spontaneous mutations in the genome and alter its evolutionary trajectory.
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36
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An automated and combinative method for the predictive ranking of candidate effector proteins of fungal plant pathogens. Sci Rep 2021; 11:19731. [PMID: 34611252 PMCID: PMC8492765 DOI: 10.1038/s41598-021-99363-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 09/16/2021] [Indexed: 01/29/2023] Open
Abstract
Fungal plant-pathogens promote infection of their hosts through the release of 'effectors'-a broad class of cytotoxic or virulence-promoting molecules. Effectors may be recognised by resistance or sensitivity receptors in the host, which can determine disease outcomes. Accurate prediction of effectors remains a major challenge in plant pathology, but if achieved will facilitate rapid improvements to host disease resistance. This study presents a novel tool and pipeline for the ranking of predicted effector candidates-Predector-which interfaces with multiple software tools and methods, aggregates disparate features that are relevant to fungal effector proteins, and applies a pairwise learning to rank approach. Predector outperformed a typical combination of secretion and effector prediction methods in terms of ranking performance when applied to a curated set of confirmed effectors derived from multiple species. We present Predector ( https://github.com/ccdmb/predector ) as a useful tool for the ranking of predicted effector candidates, which also aggregates and reports additional supporting information relevant to effector and secretome prediction in a simple, efficient, and reproducible manner.
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37
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Zhong Z, McDonald BA, Palma-Guerrero J. Tolerance to oxidative stress is associated with both oxidative stress response and inherent growth in a fungal wheat pathogen. Genetics 2021; 217:6029569. [PMID: 33724407 DOI: 10.1093/genetics/iyaa022] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 11/23/2020] [Indexed: 01/25/2023] Open
Abstract
Reactive oxygen species are toxic byproducts of aerobic respiration that are also important in mediating a diversity of cellular functions. Reactive oxygen species form an important component of plant defenses to inhibit microbial pathogens during pathogen-plant interactions. Tolerance to oxidative stress is likely to make a significant contribution to the viability and pathogenicity of plant pathogens, but the complex network of oxidative stress responses hinders identification of the genes contributing to this trait. Here, we employed a forward genetic approach to investigate the genetic architecture of oxidative stress tolerance in the fungal wheat pathogen Zymoseptoria tritici. We used quantitative trait locus (QTL) mapping of growth and melanization under axenic conditions in two cross-populations to identify genomic regions associated with tolerance to oxidative stress. We found that QTLs associated with growth under oxidative stress as well as inherent growth can affect oxidative stress tolerance, and we identified two uncharacterized genes in a major QTL associated with this trait. Our data suggest that melanization does not affect tolerance to oxidative stress, which differs from what was found for animal pathogens. This study provides a whole-genome perspective on the genetic basis of oxidative stress tolerance in a plant pathogen.
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Affiliation(s)
- Ziming Zhong
- Plant Pathology Group, Institute of Integrative Biology, ETH Zurich, 8092 Zürich, Switzerland
| | - Bruce A McDonald
- Plant Pathology Group, Institute of Integrative Biology, ETH Zurich, 8092 Zürich, Switzerland
| | - Javier Palma-Guerrero
- Plant Pathology Group, Institute of Integrative Biology, ETH Zurich, 8092 Zürich, Switzerland.,Department of Biointeractions and Crop Protection, Rothamsted Research, AL5 2JQ Harpenden, UK
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38
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Harting R, Starke J, Kusch H, Pöggeler S, Maurus I, Schlüter R, Landesfeind M, Bulla I, Nowrousian M, de Jonge R, Stahlhut G, Hoff KJ, Aßhauer KP, Thürmer A, Stanke M, Daniel R, Morgenstern B, Thomma BPHJ, Kronstad JW, Braus‐Stromeyer SA, Braus GH. A 20-kb lineage-specific genomic region tames virulence in pathogenic amphidiploid Verticillium longisporum. MOLECULAR PLANT PATHOLOGY 2021; 22:939-953. [PMID: 33955130 PMCID: PMC8295516 DOI: 10.1111/mpp.13071] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 03/30/2021] [Indexed: 05/04/2023]
Abstract
Amphidiploid fungal Verticillium longisporum strains Vl43 and Vl32 colonize the plant host Brassica napus but differ in their ability to cause disease symptoms. These strains represent two V. longisporum lineages derived from different hybridization events of haploid parental Verticillium strains. Vl32 and Vl43 carry same-sex mating-type genes derived from both parental lineages. Vl32 and Vl43 similarly colonize and penetrate plant roots, but asymptomatic Vl32 proliferation in planta is lower than virulent Vl43. The highly conserved Vl43 and Vl32 genomes include less than 1% unique genes, and the karyotypes of 15 or 16 chromosomes display changed genetic synteny due to substantial genomic reshuffling. A 20 kb Vl43 lineage-specific (LS) region apparently originating from the Verticillium dahliae-related ancestor is specific for symptomatic Vl43 and encodes seven genes, including two putative transcription factors. Either partial or complete deletion of this LS region in Vl43 did not reduce virulence but led to induction of even more severe disease symptoms in rapeseed. This suggests that the LS insertion in the genome of symptomatic V. longisporum Vl43 mediates virulence-reducing functions, limits damage on the host plant, and therefore tames Vl43 from being even more virulent.
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Affiliation(s)
- Rebekka Harting
- Department of Molecular Microbiology and GeneticsInstitute of Microbiology and Genetics and Göttingen Center for Molecular BiosciencesUniversity of GöttingenGöttingenGermany
| | - Jessica Starke
- Department of Molecular Microbiology and GeneticsInstitute of Microbiology and Genetics and Göttingen Center for Molecular BiosciencesUniversity of GöttingenGöttingenGermany
| | - Harald Kusch
- Department of Molecular Microbiology and GeneticsInstitute of Microbiology and Genetics and Göttingen Center for Molecular BiosciencesUniversity of GöttingenGöttingenGermany
| | - Stefanie Pöggeler
- Department of Genetics of Eukaryotic MicroorganismsInstitute of Microbiology and Genetics and Göttingen Center for Molecular BiosciencesUniversity of GöttingenGöttingenGermany
| | - Isabel Maurus
- Department of Molecular Microbiology and GeneticsInstitute of Microbiology and Genetics and Göttingen Center for Molecular BiosciencesUniversity of GöttingenGöttingenGermany
| | - Rabea Schlüter
- Imaging Center of the Department of BiologyUniversity of GreifswaldGreifswaldGermany
| | - Manuel Landesfeind
- Department of BioinformaticsInstitute of Microbiology and Genetics and Göttingen Center for Molecular BiosciencesUniversity of GöttingenGöttingenGermany
| | - Ingo Bulla
- Institute for Mathematics and Computer ScienceUniversity of GreifswaldGreifswaldGermany
| | - Minou Nowrousian
- Department of Molecular and Cellular BotanyRuhr‐Universität BochumBochumGermany
| | - Ronnie de Jonge
- Plant–Microbe Interactions, Department of Biology, Science4LifeUtrecht UniversityUtrechtNetherlands
- Laboratory of PhytopathologyWageningen UniversityWageningenNetherlands
| | - Gertrud Stahlhut
- Department of Genetics of Eukaryotic MicroorganismsInstitute of Microbiology and Genetics and Göttingen Center for Molecular BiosciencesUniversity of GöttingenGöttingenGermany
| | - Katharina J. Hoff
- Institute for Mathematics and Computer ScienceUniversity of GreifswaldGreifswaldGermany
- Center for Functional Genomics of MicrobesUniversity of GreifswaldGreifswaldGermany
| | - Kathrin P. Aßhauer
- Department of BioinformaticsInstitute of Microbiology and Genetics and Göttingen Center for Molecular BiosciencesUniversity of GöttingenGöttingenGermany
| | - Andrea Thürmer
- Department of Genomic and Applied MicrobiologyInstitute of Microbiology and Genetics and Göttingen Center for Molecular BiosciencesUniversity of GöttingenGöttingenGermany
| | - Mario Stanke
- Institute for Mathematics and Computer ScienceUniversity of GreifswaldGreifswaldGermany
- Center for Functional Genomics of MicrobesUniversity of GreifswaldGreifswaldGermany
| | - Rolf Daniel
- Department of Genomic and Applied MicrobiologyInstitute of Microbiology and Genetics and Göttingen Center for Molecular BiosciencesUniversity of GöttingenGöttingenGermany
| | - Burkhard Morgenstern
- Department of BioinformaticsInstitute of Microbiology and Genetics and Göttingen Center for Molecular BiosciencesUniversity of GöttingenGöttingenGermany
| | | | - James W. Kronstad
- Michael Smith Laboratories, Department of Microbiology and ImmunologyUniversity of British ColumbiaVancouverBCCanada
| | - Susanna A. Braus‐Stromeyer
- Department of Molecular Microbiology and GeneticsInstitute of Microbiology and Genetics and Göttingen Center for Molecular BiosciencesUniversity of GöttingenGöttingenGermany
| | - Gerhard H. Braus
- Department of Molecular Microbiology and GeneticsInstitute of Microbiology and Genetics and Göttingen Center for Molecular BiosciencesUniversity of GöttingenGöttingenGermany
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39
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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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40
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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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41
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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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42
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Hafeez AN, Arora S, Ghosh S, Gilbert D, Bowden RL, Wulff BBH. Creation and judicious application of a wheat resistance gene atlas. MOLECULAR PLANT 2021; 14:1053-1070. [PMID: 33991673 DOI: 10.1016/j.molp.2021.05.014] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 04/12/2021] [Accepted: 05/11/2021] [Indexed: 05/18/2023]
Abstract
Disease-resistance (R) gene cloning in wheat (Triticum aestivum) has been accelerated by the recent surge of genomic resources, facilitated by advances in sequencing technologies and bioinformatics. However, with the challenges of population growth and climate change, it is vital not only to clone and functionally characterize a few handfuls of R genes, but also to do so at a scale that would facilitate the breeding and deployment of crops that can recognize the wide range of pathogen effectors that threaten agroecosystems. Pathogen populations are continually changing, and breeders must have tools and resources available to rapidly respond to those changes if we are to safeguard our daily bread. To meet this challenge, we propose the creation of a wheat R-gene atlas by an international community of researchers and breeders. The atlas would consist of an online directory from which sources of resistance could be identified and deployed to achieve more durable resistance to the major wheat pathogens, such as wheat rusts, blotch diseases, powdery mildew, and wheat blast. We present a costed proposal detailing how the interacting molecular components governing disease resistance could be captured from both the host and the pathogen through biparental mapping, mutational genomics, and whole-genome association genetics. We explore options for the configuration and genotyping of diversity panels of hexaploid and tetraploid wheat, as well as their wild relatives and major pathogens, and discuss how the atlas could inform a dynamic, durable approach to R-gene deployment. Set against the current magnitude of wheat yield losses worldwide, recently estimated at 21%, this endeavor presents one route for bringing R genes from the lab to the field at a considerable speed and quantity.
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Affiliation(s)
| | - Sanu Arora
- John Innes Centre, Norwich Research Park, Norwich, UK
| | - Sreya Ghosh
- John Innes Centre, Norwich Research Park, Norwich, UK
| | - David Gilbert
- John Innes Centre, Norwich Research Park, Norwich, UK
| | - Robert L Bowden
- USDA-ARS, Hard Winter Wheat Genetics Research Unit, Manhattan, KS 66506, USA
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Comparative Genomics of Eight Fusarium graminearum Strains with Contrasting Aggressiveness Reveals an Expanded Open Pangenome and Extended Effector Content Signatures. Int J Mol Sci 2021; 22:ijms22126257. [PMID: 34200775 PMCID: PMC8230406 DOI: 10.3390/ijms22126257] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 06/02/2021] [Accepted: 06/07/2021] [Indexed: 01/25/2023] Open
Abstract
Fusarium graminearum, the primary cause of Fusarium head blight (FHB) in small-grain cereals, demonstrates remarkably variable levels of aggressiveness in its host, producing different infection dynamics and contrasted symptom severity. While the secreted proteins, including effectors, are thought to be one of the essential components of aggressiveness, our knowledge of the intra-species genomic diversity of F. graminearum is still limited. In this work, we sequenced eight European F. graminearum strains of contrasting aggressiveness to characterize their respective genome structure, their gene content and to delineate their specificities. By combining the available sequences of 12 other F. graminearum strains, we outlined a reference pangenome that expands the repertoire of the known genes in the reference PH-1 genome by 32%, including nearly 21,000 non-redundant sequences and gathering a common base of 9250 conserved core-genes. More than 1000 genes with high non-synonymous mutation rates may be under diverse selection, especially regarding the trichothecene biosynthesis gene cluster. About 900 secreted protein clusters (SPCs) have been described. Mostly localized in the fast sub-genome of F. graminearum supposed to evolve rapidly to promote adaptation and rapid responses to the host's infection, these SPCs gather a range of putative proteinaceous effectors systematically found in the core secretome, with the chloroplast and the plant nucleus as the main predicted targets in the host cell. This work describes new knowledge on the intra-species diversity in F. graminearum and emphasizes putative determinants of aggressiveness, providing a wealth of new candidate genes potentially involved in the Fusarium head blight disease.
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Badet T, Fouché S, Hartmann FE, Zala M, Croll D. Machine-learning predicts genomic determinants of meiosis-driven structural variation in a eukaryotic pathogen. Nat Commun 2021; 12:3551. [PMID: 34112792 PMCID: PMC8192914 DOI: 10.1038/s41467-021-23862-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 05/11/2021] [Indexed: 02/05/2023] Open
Abstract
Species harbor extensive structural variation underpinning recent adaptive evolution. However, the causality between genomic features and the induction of new rearrangements is poorly established. Here, we analyze a global set of telomere-to-telomere genome assemblies of a fungal pathogen of wheat to establish a nucleotide-level map of structural variation. We show that the recent emergence of pesticide resistance has been disproportionally driven by rearrangements. We use machine learning to train a model on structural variation events based on 30 chromosomal sequence features. We show that base composition and gene density are the major determinants of structural variation. Retrotransposons explain most inversion, indel and duplication events. We apply our model to Arabidopsis thaliana and show that our approach extends to more complex genomes. Finally, we analyze complete genomes of haploid offspring in a four-generation pedigree. Meiotic crossover locations are enriched for new rearrangements consistent with crossovers being mutational hotspots. The model trained on species-wide structural variation accurately predicts the position of >74% of newly generated variants along the pedigree. The predictive power highlights causality between specific sequence features and the induction of chromosomal rearrangements. Our work demonstrates that training sequence-derived models can accurately identify regions of intrinsic DNA instability in eukaryotic genomes.
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Affiliation(s)
- Thomas Badet
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Simone Fouché
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
- Plant Pathology, Institute of Integrative Biology, ETH Zurich, Zurich, Switzerland
| | - Fanny E Hartmann
- Ecologie Systématique Evolution, Bâtiment 360, Univ. Paris-Sud, AgroParisTech, CNRS, Université Paris-Saclay, Orsay, France
| | - Marcello Zala
- Plant Pathology, Institute of Integrative Biology, ETH Zurich, Zurich, Switzerland
| | - Daniel Croll
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland.
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Singh NK, Badet T, Abraham L, Croll D. Rapid sequence evolution driven by transposable elements at a virulence locus in a fungal wheat pathogen. BMC Genomics 2021; 22:393. [PMID: 34044766 PMCID: PMC8157644 DOI: 10.1186/s12864-021-07691-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 05/07/2021] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Plant pathogens cause substantial crop losses in agriculture production and threaten food security. Plants evolved the ability to recognize virulence factors and pathogens have repeatedly escaped recognition due rapid evolutionary change at pathogen virulence loci (i.e. effector genes). The presence of transposable elements (TEs) in close physical proximity of effector genes can have important consequences for gene regulation and sequence evolution. Species-wide investigations of effector gene loci remain rare hindering our ability to predict pathogen evolvability. RESULTS Here, we performed genome-wide association studies (GWAS) on a highly polymorphic mapping population of 120 isolates of Zymoseptoria tritici, the most damaging pathogen of wheat in Europe. We identified a major locus underlying significant variation in reproductive success of the pathogen and damage caused on the wheat cultivar Claro. The most strongly associated locus is intergenic and flanked by genes encoding a predicted effector and a serine-type endopeptidase. The center of the locus contained a highly dynamic region consisting of multiple families of TEs. Based on a large global collection of assembled genomes, we show that the virulence locus has undergone substantial recent sequence evolution. Large insertion and deletion events generated length variation between the flanking genes by a factor of seven (5-35 kb). The locus showed also strong signatures of genomic defenses against TEs (i.e. RIP) contributing to the rapid diversification of the locus. CONCLUSIONS In conjunction, our work highlights the power of combining GWAS and population-scale genome analyses to investigate major effect loci in pathogens.
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Affiliation(s)
- Nikhil Kumar Singh
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, 2000, Neuchâtel, Switzerland
| | - Thomas Badet
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, 2000, Neuchâtel, Switzerland
| | - Leen Abraham
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, 2000, Neuchâtel, Switzerland
| | - Daniel Croll
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, 2000, Neuchâtel, Switzerland.
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Bertazzoni S, Jones DAB, Phan HT, Tan KC, Hane JK. Chromosome-level genome assembly and manually-curated proteome of model necrotroph Parastagonospora nodorum Sn15 reveals a genome-wide trove of candidate effector homologs, and redundancy of virulence-related functions within an accessory chromosome. BMC Genomics 2021; 22:382. [PMID: 34034667 PMCID: PMC8146201 DOI: 10.1186/s12864-021-07699-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 05/11/2021] [Indexed: 11/19/2022] Open
Abstract
Background The fungus Parastagonospora nodorum causes septoria nodorum blotch (SNB) of wheat (Triticum aestivum) and is a model species for necrotrophic plant pathogens. The genome assembly of reference isolate Sn15 was first reported in 2007. P. nodorum infection is promoted by its production of proteinaceous necrotrophic effectors, three of which are characterised – ToxA, Tox1 and Tox3. Results A chromosome-scale genome assembly of P. nodorum Australian reference isolate Sn15, which combined long read sequencing, optical mapping and manual curation, produced 23 chromosomes with 21 chromosomes possessing both telomeres. New transcriptome data were combined with fungal-specific gene prediction techniques and manual curation to produce a high-quality predicted gene annotation dataset, which comprises 13,869 high confidence genes, and an additional 2534 lower confidence genes retained to assist pathogenicity effector discovery. Comparison to a panel of 31 internationally-sourced isolates identified multiple hotspots within the Sn15 genome for mutation or presence-absence variation, which was used to enhance subsequent effector prediction. Effector prediction resulted in 257 candidates, of which 98 higher-ranked candidates were selected for in-depth analysis and revealed a wealth of functions related to pathogenicity. Additionally, 11 out of the 98 candidates also exhibited orthology conservation patterns that suggested lateral gene transfer with other cereal-pathogenic fungal species. Analysis of the pan-genome indicated the smallest chromosome of 0.4 Mbp length to be an accessory chromosome (AC23). AC23 was notably absent from an avirulent isolate and is predominated by mutation hotspots with an increase in non-synonymous mutations relative to other chromosomes. Surprisingly, AC23 was deficient in effector candidates, but contained several predicted genes with redundant pathogenicity-related functions. Conclusions We present an updated series of genomic resources for P. nodorum Sn15 – an important reference isolate and model necrotroph – with a comprehensive survey of its predicted pathogenicity content. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07699-8.
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Affiliation(s)
| | - Darcy A B Jones
- Centre for Crop & Disease Management, Curtin University, Perth, Australia
| | - Huyen T Phan
- Centre for Crop & Disease Management, Curtin University, Perth, Australia.
| | - Kar-Chun Tan
- Centre for Crop & Disease Management, Curtin University, Perth, Australia.
| | - James K Hane
- Centre for Crop & Disease Management, Curtin University, Perth, Australia. .,Curtin Institute for Computation, Curtin University, Perth, Australia.
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Calcino AD, Kenny NJ, Gerdol M. Single individual structural variant detection uncovers widespread hemizygosity in molluscs. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200153. [PMID: 33813894 PMCID: PMC8059565 DOI: 10.1098/rstb.2020.0153] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/07/2021] [Indexed: 11/12/2022] Open
Abstract
The advent of complete genomic sequencing has opened a window into genomic phenomena obscured by fragmented assemblies. A good example of these is the existence of hemizygous regions of autosomal chromosomes, which can result in marked differences in gene content between individuals within species. While these hemizygous regions, and presence/absence variation of genes that can result, are well known in plants, firm evidence has only recently emerged for their existence in metazoans. Here, we use recently published, complete genomes from wild-caught molluscs to investigate the prevalence of hemizygosity across a well-known and ecologically important clade. We show that hemizygous regions are widespread in mollusc genomes, not clustered in individual chromosomes, and often contain genes linked to transposition, DNA repair and stress response. With targeted investigations of HSP70-12 and C1qDC, we also show how individual gene families are distributed within pan-genomes. This work suggests that extensive pan-genomes are widespread across the conchiferan Mollusca, and represent useful tools for genomic evolution, allowing the maintenance of additional genetic diversity within the population. As genomic sequencing and re-sequencing becomes more routine, the prevalence of hemizygosity, and its impact on selection and adaptation, are key targets for research across the tree of life. This article is part of the Theo Murphy meeting issue 'Molluscan genomics: broad insights and future directions for a neglected phylum'.
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Affiliation(s)
- Andrew D. Calcino
- Department of Evolutionary Biology, Integrative Zoology, University of Vienna, Althanstrasse 14, Vienna 1090, Austria
| | - Nathan J. Kenny
- Life Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, UK
| | - Marco Gerdol
- Department of Life Sciences, University of Trieste, Via Licio Giorgieri 5, 34127 Trieste, Italy
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Yildiz G, Ozkilinc H. Pan-Mitogenomics Approach Discovers Diversity and Dynamism in the Prominent Brown Rot Fungal Pathogens. Front Microbiol 2021; 12:647989. [PMID: 34054750 PMCID: PMC8149612 DOI: 10.3389/fmicb.2021.647989] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 03/29/2021] [Indexed: 01/26/2023] Open
Abstract
Monilinia fructicola and Monilinia laxa species are the most destructive and economically devastating fungal plant pathogens causing brown rot disease on stone and pome fruits worldwide. Mitochondrial genomes (mitogenomes) play critical roles influencing the mechanisms and directions of the evolution of fungal pathogens. The pan-mitogenomics approach predicts core and accessory regions of the mitochondrial genomes and explains the gain or loss of variation within and between species. The present study is a fungal pan-mitogenome of M. fructicola (N = 8) and M. laxa (N = 8) species. The completely sequenced and annotated mitogenomes showed high variability in size within and between the species. The mitogenomes of M. laxa were larger, ranging from 178,351 to 179,780bp, than the mitogenomes of M. fructicola, ranging from 158,607 to 167,838bp. However, size variation within the species showed that M. fructicola isolates were more variable in the size range than M. laxa isolates. All the mitogenomes included conserved mitochondrial genes, as well as variable regions including different mobile introns encoding homing endonucleases or maturase, non-coding introns, and repetitive elements. The linear model analysis supported the hypothesis that the mitogenome size expansion is due to presence of variable (accessory) regions. Gene synteny was mostly conserved among all samples, with the exception for order of the rps3 in the mitogenome of one isolate. The mitogenomes presented AT richness; however, A/T and G/C skew varied among the mitochondrial genes. The purifying selection was detected in almost all the protein-coding genes (PCGs) between the species. However, cytochrome b was the only gene showing a positive selection signal among the total samples. Combined datasets of amino acid sequences of 14 core mitochondrial PCGs and rps3 obtained from this study together with published mitochondrial genome sequences from some other species from Heliotales were used to infer a maximum likelihood (ML) phylogenetic tree. ML tree indicated that both Monilinia species highly diverged from each other as well as some other fungal species from the same order. Mitogenomes harbor much information about the evolution of fungal plant pathogens, which could be useful to predict pathogenic life strategies.
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Affiliation(s)
- Gozde Yildiz
- School of Graduate Studies, MSc Program in Biomolecular Sciences, Çanakkale Onsekiz Mart University, Çanakkale, Turkey
| | - Hilal Ozkilinc
- School of Graduate Studies, MSc Program in Biomolecular Sciences, Çanakkale Onsekiz Mart University, Çanakkale, Turkey.,Faculty of Arts and Sciences, Department of Molecular Biology and Genetics, Çanakkale Onsekiz Mart University, Çanakkale, Turkey
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Möller M, Habig M, Lorrain C, Feurtey A, Haueisen J, Fagundes WC, Alizadeh A, Freitag M, Stukenbrock EH. Recent loss of the Dim2 DNA methyltransferase decreases mutation rate in repeats and changes evolutionary trajectory in a fungal pathogen. PLoS Genet 2021; 17:e1009448. [PMID: 33750960 PMCID: PMC8016269 DOI: 10.1371/journal.pgen.1009448] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 04/01/2021] [Accepted: 02/26/2021] [Indexed: 01/04/2023] Open
Abstract
DNA methylation is found throughout all domains of life, yet the extent and function of DNA methylation differ among eukaryotes. Strains of the plant pathogenic fungus Zymoseptoria tritici appeared to lack cytosine DNA methylation (5mC) because gene amplification followed by Repeat-Induced Point mutation (RIP) resulted in the inactivation of the dim2 DNA methyltransferase gene. 5mC is, however, present in closely related sister species. We demonstrate that inactivation of dim2 occurred recently as some Z. tritici isolates carry a functional dim2 gene. Moreover, we show that dim2 inactivation occurred by a different path than previously hypothesized. We mapped the genome-wide distribution of 5mC in strains with or without functional dim2 alleles. Presence of functional dim2 correlates with high levels of 5mC in transposable elements (TEs), suggesting a role in genome defense. We identified low levels of 5mC in strains carrying non-functional dim2 alleles, suggesting that 5mC is maintained over time, presumably by an active Dnmt5 DNA methyltransferase. Integration of a functional dim2 allele in strains with mutated dim2 restored normal 5mC levels, demonstrating de novo cytosine methylation activity of Dim2. To assess the importance of 5mC for genome evolution, we performed an evolution experiment, comparing genomes of strains with high levels of 5mC to genomes of strains lacking functional dim2. We found that presence of a functional dim2 allele alters nucleotide composition by promoting C to T transitions (C→T) specifically at CpA (CA) sites during mitosis, likely contributing to TE inactivation. Our results show that 5mC density at TEs is a polymorphic trait in Z. tritici populations that can impact genome evolution.
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Affiliation(s)
- Mareike Möller
- Environmental Genomics, Christian-Albrechts University, Kiel, Germany
- Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Michael Habig
- Environmental Genomics, Christian-Albrechts University, Kiel, Germany
- Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Cécile Lorrain
- Environmental Genomics, Christian-Albrechts University, Kiel, Germany
- Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Alice Feurtey
- Environmental Genomics, Christian-Albrechts University, Kiel, Germany
- Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Janine Haueisen
- Environmental Genomics, Christian-Albrechts University, Kiel, Germany
- Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Wagner C. Fagundes
- Environmental Genomics, Christian-Albrechts University, Kiel, Germany
- Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Alireza Alizadeh
- Department of Plant Protection, Faculty of Agriculture, Azarbaijan Shahid Madani University, Tabriz, Iran
| | - Michael Freitag
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR, United States of America
| | - Eva H. Stukenbrock
- Environmental Genomics, Christian-Albrechts University, Kiel, Germany
- Max Planck Institute for Evolutionary Biology, Plön, Germany
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50
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Reinhardt D, Roux C, Corradi N, Di Pietro A. Lineage-Specific Genes and Cryptic Sex: Parallels and Differences between Arbuscular Mycorrhizal Fungi and Fungal Pathogens. TRENDS IN PLANT SCIENCE 2021; 26:111-123. [PMID: 33011084 DOI: 10.1016/j.tplants.2020.09.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 08/29/2020] [Accepted: 09/08/2020] [Indexed: 05/25/2023]
Abstract
Arbuscular mycorrhizal fungi (AMF) live as obligate root symbionts on almost all land plants. They have long been regarded as ancient asexuals that have propagated clonally for millions of years. However, genomic studies in Rhizophagus irregularis and other AMF revealed many features indicative of sex. Surprisingly, comparative genomics of conspecific isolates of R. irregularis revealed an unexpected interstrain diversity, suggesting that AMF carry a high number of lineage-specific (LS) genes. Intriguingly, cryptic sex and LS genomic regions have previously been reported in a number of fungal pathogens of plants and humans. Here, we discuss these genomic similarities and highlight their potential relevance for AMF adaptation to the environment and for symbiotic functioning.
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Affiliation(s)
- Didier Reinhardt
- Department of Biology, University of Fribourg, Fribourg, Switzerland.
| | - Christophe Roux
- Laboratoire de Recherche en Sciences Végétales, UPS, CNRS, Université de Toulouse, Castanet-Tolosan 31326, France
| | - Nicolas Corradi
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | - Antonio Di Pietro
- Departamento de Genética, Universidad de Cordoba, 14071 Cordoba, Spain
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