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Manathunga KK, Gunasekara NW, Meegahakumbura MK, Ratnaweera PB, Faraj TK, Wanasinghe DN. Exploring Endophytic Fungi as Natural Antagonists against Fungal Pathogens of Food Crops. J Fungi (Basel) 2024; 10:606. [PMID: 39330366 PMCID: PMC11433156 DOI: 10.3390/jof10090606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2024] [Revised: 08/17/2024] [Accepted: 08/21/2024] [Indexed: 09/28/2024] Open
Abstract
The yield and quality of cultivated food crops are frequently compromised by the prevalent threat from fungal pathogens that can cause widespread damage in both the pre-harvest and post-harvest stages. This paper investigates the challenges posed by fungal pathogens to the sustainability and yield of essential food crops, leading to significant economic and food security repercussions. The paper critiques the long-standing reliance on synthetic fungicides, emphasizing the environmental and health concerns arising from their widespread and occasionally inappropriate use. In response, the paper explores the potential of biological control agents, specifically endophytic fungi in advancing sustainable agricultural practices. Through their diverse symbiotic relationships with host plants, these fungi exhibit strong antagonistic capabilities against phytopathogenic fungi by producing various bioactive compounds and promoting plant growth. The review elaborates on the direct and indirect mechanisms of endophytic antagonism, such as antibiosis, mycoparasitism, induction of host resistance, and competition for resources, which collectively contribute to inhibiting pathogenic fungal growth. This paper consolidates the crucial role of endophytic fungi, i.e., Acremonium, Alternaria, Arthrinium, Aspergillus, Botryosphaeria, Chaetomium, Cladosporium, Cevidencealdinia, Epicoccum, Fusarium, Gliocladium, Muscodor, Nigrospora, Paecilomyces, Penicillium, Phomopsis, Pichia, Pochonia, Pythium, Ramichloridium, Rosellinia, Talaromyces, Trichoderma, Verticillium, Wickerhamomyces, and Xylaria, in biological control, supported by the evidence drawn from more than 200 research publications. The paper pays particular attention to Muscodor, Penicillium, and Trichoderma as prominent antagonists. It also emphasizes the need for future genetic-level research to enhance the application of endophytes in biocontrol strategies aiming to highlight the importance of endophytic fungi in facilitating the transition towards more sustainable and environmentally friendly agricultural systems.
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Affiliation(s)
- Kumudu K. Manathunga
- Department of Science and Technology, Faculty of Applied Sciences, Uva Wellassa University, Badulla 90000, Sri Lanka; (K.K.M.); (P.B.R.)
| | - Niranjan W. Gunasekara
- Department of Export Agriculture, Faculty of Animal Science and Export Agriculture, Uva Wellassa University, Badulla 90000, Sri Lanka;
| | - Muditha K. Meegahakumbura
- Department of Export Agriculture, Faculty of Animal Science and Export Agriculture, Uva Wellassa University, Badulla 90000, Sri Lanka;
| | - Pamoda B. Ratnaweera
- Department of Science and Technology, Faculty of Applied Sciences, Uva Wellassa University, Badulla 90000, Sri Lanka; (K.K.M.); (P.B.R.)
| | - Turki Kh. Faraj
- Department of Soil Science, College of Food and Agriculture Sciences, King Saud University, P.O. Box 145111, Riyadh 11362, Saudi Arabia;
| | - Dhanushka N. Wanasinghe
- Department of Soil Science, College of Food and Agriculture Sciences, King Saud University, P.O. Box 145111, Riyadh 11362, Saudi Arabia;
- Honghe Center for Mountain Futures, Kunming Institute of Botany, Chinese Academy of Sciences, Honghe 654400, China
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Yeh YW, Kirschner R. An independent Taiwanese lineage of powdery mildew on the endemic host species Koelreuteria henryi. BOTANICAL STUDIES 2024; 65:22. [PMID: 39028392 PMCID: PMC11264589 DOI: 10.1186/s40529-024-00431-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2024] [Accepted: 07/04/2024] [Indexed: 07/20/2024]
Abstract
BACKGROUND Powdery mildews (Erysiphaceae, Ascomycota) are common plant disease agents and also cause stress for forest and fruit trees worldwide as well as in Taiwan. The powdery mildew Erysiphe bulbouncinula on Koelreuteria host trees was considered an endemic species in China. While in China the host was K. paniculata and only the teleomorph stage found, the anamorph and the teleomorph were both recorded for the host in Taiwan, K. henryi. We aimed to clarify the relationship of the powdery mildews recorded under E. bulbouncinula with an apparently disjunct distribution. RESULTS Specimens of powdery mildew on K. henryi from Taiwan were characterized based on the anamorph morphology and DNA sequences. They revealed a new record of Sawadaea koelreuteriae for this host species and Taiwan and a new species of Erysiphe, E. formosana, sister to E. bulbouncinula from China. CONCLUSIONS In Erysiphe on Koelreuteria hosts, speciation of plant parasitic fungi seems to be correlated with disjunct host and geographic distribution possibly shaped by extinction of potential host species which are known only as fossils. Two of the three extant East Asian species of Koelreuteria are now known as hosts of specific Erysiphe species. We may predict a further not yet discovered Erysiphe species on the third East Asian species, K. bipinnata, in South and Southwest China. In the speciation in Sawadaea, the extinction events in Koelreuteria can be excluded from being involved.
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Affiliation(s)
- Yu-Wei Yeh
- School of Forestry and Resource Conservation, National Taiwan University, Roosevelt Rd. Sec. 4 No. 1, Taipei City, Taiwan
- Mycology Research Group, Faculty of Biological Sciences, Goethe University Frankfurt Am Main, Biologicum, Max-Von-Laue-Straße 13, Frankfurt Am Main, Germany
| | - Roland Kirschner
- School of Forestry and Resource Conservation, National Taiwan University, Roosevelt Rd. Sec. 4 No. 1, Taipei City, Taiwan.
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Kunz L, Poretti M, Praz CR, Müller MC, Wyler M, Keller B, Wicker T, Bourras S. High-Copy Transposons from a Pathogen Give Rise to a Conserved sRNA Family with a Novel Host Immunity Target. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2024; 37:545-551. [PMID: 38551853 DOI: 10.1094/mpmi-10-23-0176-sc] [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: 07/29/2024]
Abstract
Small RNAs (sRNAs) are involved in gene silencing in multiple ways, including through cross-kingdom transfers from parasites to their hosts. Little is known about the evolutionary mechanisms enabling eukaryotic microbes to evolve functional mimics of host small regulatory RNAs. Here, we describe the identification and functional characterization of SINE_sRNA1, an sRNA family derived from highly abundant short interspersed nuclear element (SINE) retrotransposons in the genome of the wheat powdery mildew pathogen. SINE_sRNA1 is encoded by a sequence motif that is conserved in multiple SINE families and corresponds to a functional plant microRNA (miRNA) mimic targeting Tae_AP1, a wheat gene encoding an aspartic protease only found in monocots. Tae_AP1 has a novel function enhancing both pattern-triggered immunity (PTI) and effector-triggered immunity (ETI), thereby contributing to the cross activation of plant defenses. We conclude that SINE_sRNA1 and Tae_AP1 are functional innovations, suggesting the contribution of transposons to the evolutionary arms race between a parasite and its host. [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)
- Lukas Kunz
- Department of Plant and Microbial Biology, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
| | - Manuel Poretti
- Department of Plant and Microbial Biology, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
- Department of Biology, University of Fribourg, Chemin du Musée 10, CH-1700 Fribourg, Switzerland
| | - Coraline R Praz
- Department of Plant and Microbial Biology, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
- Center of Biotechnology and Genomics of Plants, Polytechnic University of Madrid, Campus de Montegancedo, 28223 Madrid, Spain
| | - Marion C Müller
- Department of Plant and Microbial Biology, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
- Chair of Phytopathology, TUM School of Life Sciences, Technical University of Munich, Emil-Ramann-Str. 2, 85354 Freising-Weihenstephan, Germany
| | - Michele Wyler
- Department of Plant and Microbial Biology, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
- MWSchmid GmbH, Hauptstrasse 34, CH-8750 Glarus, Switzerland
| | - Beat Keller
- Department of Plant and Microbial Biology, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
| | - Thomas Wicker
- Department of Plant and Microbial Biology, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
| | - Salim Bourras
- Department of Plant and Microbial Biology, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
- Department of Plant Biology, Swedish University of Agricultural Sciences, Almas Allé 5, 75007 Uppsala, Sweden
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Kusch S, Qian J, Loos A, Kümmel F, Spanu PD, Panstruga R. Long-term and rapid evolution in powdery mildew fungi. Mol Ecol 2024; 33:e16909. [PMID: 36862075 DOI: 10.1111/mec.16909] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 02/06/2023] [Accepted: 02/20/2023] [Indexed: 03/03/2023]
Abstract
The powdery mildew fungi (Erysiphaceae) are globally distributed plant pathogens with a range of more than 10,000 plant hosts. In this review, we discuss the long- and short-term evolution of these obligate biotrophic fungi and outline their diversity with respect to morphology, lifestyle, and host range. We highlight their remarkable ability to rapidly overcome plant immunity, evolve fungicide resistance, and broaden their host range, for example, through adaptation and hybridization. Recent advances in genomics and proteomics, particularly in cereal powdery mildews (genus Blumeria), provided first insights into mechanisms of genomic adaptation in these fungi. Transposable elements play key roles in shaping their genomes, where even close relatives exhibit diversified patterns of recent and ongoing transposon activity. These transposons are ubiquitously distributed in the powdery mildew genomes, resulting in a highly adaptive genome architecture lacking obvious regions of conserved gene space. Transposons can also be neofunctionalized to encode novel virulence factors, particularly candidate secreted effector proteins, which may undermine the plant immune system. In cereals like barley and wheat, some of these effectors are recognized by plant immune receptors encoded by resistance genes with numerous allelic variants. These effectors determine incompatibility ("avirulence") and evolve rapidly through sequence diversification and copy number variation. Altogether, powdery mildew fungi possess plastic genomes that enable their fast evolutionary adaptation towards overcoming plant immunity, host barriers, and chemical stress such as fungicides, foreshadowing future outbreaks, host range shifts and expansions as well as potential pandemics by these pathogens.
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Affiliation(s)
- Stefan Kusch
- Unit of Plant Molecular Cell Biology, Institute for Biology I, RWTH Aachen University, Aachen, Germany
| | - Jiangzhao Qian
- Unit of Plant Molecular Cell Biology, Institute for Biology I, RWTH Aachen University, Aachen, Germany
| | - Anne Loos
- Unit of Plant Molecular Cell Biology, Institute for Biology I, RWTH Aachen University, Aachen, Germany
| | - Florian Kümmel
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Pietro D Spanu
- Unit of Plant Molecular Cell Biology, Institute for Biology I, RWTH Aachen University, Aachen, Germany
- Imperial College, London, UK
| | - Ralph Panstruga
- Unit of Plant Molecular Cell Biology, Institute for Biology I, RWTH Aachen University, Aachen, Germany
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Transcriptional response to host chemical cues underpins the expansion of host range in a fungal plant pathogen lineage. THE ISME JOURNAL 2022; 16:138-148. [PMID: 34282282 PMCID: PMC8692328 DOI: 10.1038/s41396-021-01058-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 06/26/2021] [Accepted: 07/05/2021] [Indexed: 02/07/2023]
Abstract
The host range of parasites is an important factor in assessing the dynamics of disease epidemics. The evolution of pathogens to accommodate new hosts may lead to host range expansion, a process the molecular bases of which are largely enigmatic. The fungus Sclerotinia sclerotiorum has been reported to parasitize more than 400 plant species from diverse eudicot families while its close relative, S. trifoliorum, is restricted to plants from the Fabaceae family. We analyzed S. sclerotiorum global transcriptome reprogramming on hosts from six botanical families and reveal a flexible, host-specific transcriptional program. We generated a chromosome-level genome assembly for S. trifoliorum and found near-complete gene space conservation in two representative strains of broad and narrow host range Sclerotinia species. However, S. trifoliorum showed increased sensitivity to the Brassicaceae defense compound camalexin. Comparative analyses revealed a lack of transcriptional response to camalexin in the S. trifoliorum strain and suggest that regulatory variation in detoxification and effector genes at the population level may associate with the genetic accommodation of Brassicaceae in the Sclerotinia host range. Our work proposes transcriptional plasticity and the co-existence of signatures for generalist and polyspecialist adaptive strategies in the genome of a plant pathogen.
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Discovery of a novel powdery mildew (Blumeria graminis) resistance locus in rye (Secale cereale L.). Sci Rep 2021; 11:23057. [PMID: 34845285 PMCID: PMC8630102 DOI: 10.1038/s41598-021-02488-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 11/16/2021] [Indexed: 11/20/2022] Open
Abstract
Powdery mildew is one of the most destructive diseases in the world, causing substantial grain yield losses and quality reduction in cereal crops. At present 23 powdery mildew resistance genes have been identified in rye, of which the majority are in wheat-rye translocation lines developed for wheat improvement. Here, we investigated the genetics underlying powdery mildew resistance in the Gülzow-type elite hybrid rye (Secale cereale L.) breeding germplasm. In total, 180 inbred breeding lines were genotyped using the state-of-the-art 600 K SNP array and phenotyped for infection type against three distinct field populations of B. graminis f. sp. secalis from Northern Germany (2013 and 2018) and Denmark (2020). We observed a moderate level of powdery mildew resistance in the non-restorer germplasm population, and by performing a genome-wide association study using 261,406 informative SNP markers, we identified a powdery mildew resistance locus, provisionally denoted PmNOS1, on the distal tip of chromosome arm 7RL. Using recent advances in rye genomic resources, we investigated whether nucleotide-binding leucine-rich repeat genes residing in the identified 17 Mbp block associated with PmNOS1 on recent reference genomes resembled known Pm genes.
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Yuan H, Jin C, Pei H, Zhao L, Li X, Li J, Huang W, Fan R, Liu W, Shen QH. The Powdery Mildew Effector CSEP0027 Interacts With Barley Catalase to Regulate Host Immunity. FRONTIERS IN PLANT SCIENCE 2021; 12:733237. [PMID: 34567043 PMCID: PMC8458882 DOI: 10.3389/fpls.2021.733237] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 08/19/2021] [Indexed: 06/01/2023]
Abstract
Powdery mildew is one of the most important fungal pathogen diseases. The genome of barley mildew fungus, Blumeria graminis f. sp. hordei (Bgh), encodes a large number of candidate secreted effector proteins (CSEPs). So far, the function and mechanism of most CSEPs remain largely unknown. Here, we identify a Bgh effector CSEP0027, a member of family 41, triggering cell death in Nicotiana benthamiana. CSEP0027 contains a functional signal peptide (SP), verified by yeast secretion assay. We show that CSEP0027 promotes Bgh virulence in barley infection using transient gene expression and host-induced gene silencing (HIGS). Barley catalase HvCAT1 is identified as a CSEP0027 interactor by yeast two-hybrid (Y2H) screening, and the interaction is verified in yeast, in vitro and in vivo. The coexpression of CSEP0027 and HvCAT1 in barley cells results in altered localization of HvCAT1 from the peroxisome to the nucleus. Barley stripe mosaic virus (BSMV)-silencing and transiently-induced gene silencing (TIGS) assays reveal that HvCAT1 is required for barley immunity against Bgh. We propose that CSEP0027 interacts with barley HvCAT1 to regulate the host immunity and likely reactive oxygen species (ROS) homeostasis to promote fungal virulence during barley infection.
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Affiliation(s)
- Hongbo Yuan
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences (CAS), Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Cong Jin
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences (CAS), Beijing, China
| | - Hongcui Pei
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences (CAS), Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Lifang Zhao
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences (CAS), Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Xue Li
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences (CAS), Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Jiali Li
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences (CAS), Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Wanting Huang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences (CAS), Beijing, China
- School of Life Sciences, Yunnan University, Kunming, China
| | - Renchun Fan
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences (CAS), Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Wende Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences (CAS), Beijing, China
| | - Qian-Hua Shen
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences (CAS), Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
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He H, Du H, Liu R, Liu T, Yang L, Gong S, Tang Z, Du H, Liu C, Han R, Sun W, Wang L, Zhu S. Characterization of a new gene for resistance to wheat powdery mildew on chromosome 1RL of wild rye Secale sylvestre. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2021; 134:887-896. [PMID: 33388886 DOI: 10.1007/s00122-020-03739-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 11/18/2020] [Indexed: 06/12/2023]
Abstract
PmSESY, a new wheat powdery mildew resistance gene was characterized and genetically mapped to the terminal region of chromosome 1RL of wild rye Secale sylvestre. The genus Secale is an important resource for wheat improvement. The Secale species are usually considered as non-adapted hosts of Blumeria graminis f. sp. tritici (Bgt) that causes wheat powdery mildew. However, as a wild species of cultivated rye, S. sylvestre is rarely studied. Here, we reported that 25 S. sylvestre accessions were susceptible to isolate BgtYZ01, whereas the other five confer effective resistance to all the tested isolates of Bgt. A population was then constructed by crossing the resistant accession SESY-01 with the susceptible accession SESY-11. Genetic analysis showed that the resistance in SESY-01 was controlled by a single dominant gene, temporarily designated as PmSESY. Subsequently, combining bulked segregant RNA-Seq (BSR-Seq) analysis with molecular analysis, PmSESY was mapped into a 1.88 cM genetic interval in the terminus of the long arm of 1R, which was closely flanked by markers Xss06 and Xss09 with genetic distances of 0.87 cM and 1.01 cM, respectively. Comparative mapping demonstrated that the corresponding physical region of the PmSESY locus was about 3.81 Mb in rye cv. Lo7 genome, where 30 disease resistance-related genes were annotated, including five NLR-type disease resistance genes, three kinase family protein genes, three leucine-rich repeat receptor-like protein kinase genes and so on. This study gives a new insight into S. sylvestre that shows divergence in response to Bgt and reports a new powdery mildew resistance gene that has potential to be used for resistance improvement in wheat.
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Affiliation(s)
- Huagang He
- School of Life Sciences, Jiangsu University, Zhenjiang, 212013, China.
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, China.
- School of Environment, Jiangsu University, Zhenjiang, 212013, China.
| | - Haonan Du
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Renkang Liu
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Tianlei Liu
- School of Life Sciences, Jiangsu University, Zhenjiang, 212013, China
| | - Lijun Yang
- Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural Sciences, Wuhan, 430064, China
| | - Shuangjun Gong
- Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural Sciences, Wuhan, 430064, China
| | - Zongxiang Tang
- College of Agronomy, Sichuan Agricultural University, Chengdu, 611130, China
| | - Haimei Du
- College of Agronomy, Sichuan Agricultural University, Chengdu, 611130, China
| | - Cheng Liu
- Crop Research Institution, Shandong Academy of Agricultural Sciences, Jinan, 250100, China
| | - Ran Han
- Crop Research Institution, Shandong Academy of Agricultural Sciences, Jinan, 250100, China
| | - Weihong Sun
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Lei Wang
- INDEL Biological Technology Corporation, Nanjing, 210000, China
| | - Shanying Zhu
- School of Environment, Jiangsu University, Zhenjiang, 212013, China.
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Zhu M, Ji J, Duan X, Shi W, Li Y. First Report of Powdery Mildew Caused by Blumeria graminis f. sp. bromi on Bromus catharticus in China. PLANT DISEASE 2020; 105:1211. [PMID: 33164669 DOI: 10.1094/pdis-09-20-1983-pdn] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Bromus catharticus, rescuegrass, is a brome grass that has been cultivated for herbage production, and been widely naturalized in many provinces of China, including Henan province. During April and May 2020, powdery mildew was found on leaves of Br. catharticus on the campus of Henan Normal University, Xinxiang city (35.3°N; 113.9°E), Henan Province, China. Abundant white or grayish irregular or coalesced circular powdery colonies were scattered on the adaxial surface of leaves and 70% of the leaf areas were affected. Some of the infected leaves either were chlorotic or senescent. About 60% of the observed plants showed powdery mildew symptoms. Conidiophores (n = 25) were 32 to 45 μm × 7 to 15 μm and composed of foot cells and conidia (mostly 6 conidia) in chains. Conidia (n = 50) were 25 to 35 μm × 10 to 15 μm, on average 30 × 13 μm, with a length/width ratio of 2.3. Chasmothecia were not found. Based on these morphologic characteristics, the pathogen was initially identified as Blumeria graminis f. sp. bromi (Braun and Cook 2012; Troch et al. 2014). B. graminis mycelia and conidia were collected, and total genomic DNA was extracted (Zhu et al. 2019). The rDNA internal transcribed spacer (ITS) region was amplified with primer pairs ITS1/ITS4. The amplicon was cloned and sequenced. The sequence (574 bp) was deposited into GenBank under Accession No. MT892940. BLASTn analysis revealed that MT892940 was 100% identical to B. graminis f. sp. bromi on Br. catharticus (AB000935, 550 of 550 nucleotides) (Takamatsu et al. 1998). Phylogenetic analysis of MT892940 and ITS of other B. graminis ff. spp. clearly indicated least two phylogenetically distinct clades of B. graminis f. sp. bromi and that MT892940 clustered with the Takamatsu vouchers. Leaf surfaces of five healthy plants were fixed at the base of a settling tower and then inoculated by blowing conidia from diseased leaves using pressurized air. Five non-inoculated plants served as controls. The inoculated and non-inoculated plants were maintained separately in two growth chambers (humidity, 60%; light/dark, 16 h/8 h; temperature, 18℃). Thirteen- to fifteen-days after inoculation, B. graminis signs and symptoms were visible on inoculated leaves, whereas control plants remained asymptomatic. The pathogenicity assays were repeated twice with the same results. The observed signs and symptoms were morphologically identical to those of the originally infected leaves. Accordingly, the causal organism of the powdery mildew was confirmed as B. graminis f. sp. bromi by morphological characteristics and ITS sequence data. B. graminis has been reported on Br. catharticus in the United States (Klingeman et al. 2018), Japan (Inuma et al. 2007) and Argentina (Delhey et al. 2003). To our best knowledge, this is the first report of B. graminis on Br. catharticus in China. Since hybridization of B. graminis ff. spp. is a mechanism of adaptation to new hosts, Br. catharticus may serve as a primary inoculum reservoir of B. graminis to infect other species (Menardo et al. 2016). This report provides fundamental information for the powdery mildew that can be used to develop control management of the disease in Br. catharticus herbage production.
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Affiliation(s)
- Mo Zhu
- Henan Normal University, 66519, College of Life Sciences, Xinxiang, Henan, China
- Henan Normal University, 66519, Henan International Joint Laboratory of Agricultural Microbial Ecology and Technology, Xinxiang, China;
| | - Jie Ji
- Henan Normal University, 66519, College of Life Sciences, Xinxiang, Henan, China;
| | - Xiao Duan
- Henan Normal University, 66519, College of Life Sciences, Xinxiang, Henan, China;
| | - Wenqi Shi
- Ministry of Agriculture and Rural Affairs, Key Laboratory of Integrated Pest Management on Crops in Central China, No.18Nanhu Avenue,Hongshan District,Wuhan,HuBei provience, Wuhan, China, 430064
- Hubei Key Laboratory of Crop Disease, Insect Pests and Weeds Control, Wuhan, China;
| | - YongFang Li
- Henan Normal University, 66519, College of Life Sciences, Xinxiang, Henan, China
- Henan Normal University, 66519, Henan International Joint Laboratory of Agricultural Microbial Ecology and Technology, Xinxiang, China;
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Zhu M, Ji J, Shi W, Li Y. Occurrence of Powdery Mildew Caused by Blumeria graminis f. sp. poae on Poa pratensis in China. PLANT DISEASE 2020; 105:1212-1212. [PMID: 33141643 DOI: 10.1094/pdis-09-20-2051-pdn] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Poa pratensis, known as bluegrass, is a perennial grass and one of the best varieties with highly valued pasture and turf grass uses. It is widely grown on golf courses and used for lawns in squares and parks (Luo et al. 2020). During April and May 2020, powdery mildew-like signs and symptoms were observed on leaves of P. pratensis in Muye Park, Xinxiang city (35.3°N; 113.9°E), Henan Province, China. White or grayish powdery masses in spots- or coalesced lesions were abundant on the adaxial surfaces of leaves and covered up to 90 % of the leaf area. Some of the mildew-infested leaves appeared chlorotic or began senescence. Mildew-infested leaves were collected to microscopically observe the morphological characteristics of this pathogen. Conidiophores were composed of foot cells, followed by one or two cells, and conidia. The ellipsoid- shaped conidia (n = 50) were 25 - 36 × 10 - 15 μm (length × width), on average 30 × 13 μm, with a length/width ratio of 2.3. Foot-cells (n = 15) were 30 - 44 μm long and 7 - 15 μm wide. On leaf surfaces, germinated conidia produced a short primary germ tube and then a long secondary germ tube that finally differentiated into a hooked appressorium. Chasmothecia were not found. Based on these morphological characteristics, the pathogen was initially identified as B. graminis f. sp. poae, the known forma specialis (f. sp.) of B. graminis on P. pratensis (Braun and Cook 2012; Troch et al. 2014). Mycelia of the pathogen were scraped from infected leaves and total genomic DNA was isolated using the method described previously (Zhu et al. 2019). The rDNA internal transcribed spacer (ITS) region was amplified applying primer pairs ITS1/ITS4 (White et al. 1990). The amplicon was cloned and sequenced by Invitrogen (Shanghai, China). The obtained sequence for the pathogen was deposited into GenBank under Accession No. MT892956 and was 100 % identical (549/549 bp) to B. graminis on P. pratensis (AB273530) (Inuma et al. 2007). In addition, the phylogenetic analysis clearly showed that the identified fungus and B. graminis f. sp. poae were clustered in the same branch. To perform pathogenicity analysis, leaf surfaces of eight healthy plants were inoculated by dusting fungal conidia from diseased leaves. Eight non-inoculated plants served as a control. The non-inoculated and inoculated plants were separately maintained in two growth chambers (humidity, 60 %; light/dark, 16 h/8 h; temperature, 18 ℃). Twelve to fourteen days after inoculation, B. graminis signs were visible on inoculated leaves, while control plants remained healthy. The pathogenicity assays were repeated twice and showed same results. Therefore, based on the morphological characteristics and molecular analysis, the pathogen was identified and confirmed as B. graminis f. sp. poae. This pathogen has been reported on P. pratensis in Switzerland and Japan (Inuma et al. 2007). This is, to our best knowledge, the first disease note reporting B. graminis on P. pratensis in China. Because the hybridization of B. graminis formae speciales (ff. spp.). allow the pathogens to adapt to new hosts, P. pratensis may serve as a primary inoculum reservoir of B. graminis to threaten other species, including cereal crops (Klingeman et al. 2018; Menardo et al. 2016). In addition, powdery mildew may negatively affect the yield and quality of grasses. Our report expands the knowledge of B. graminis f. sp. poae and provides the fundamental information for future powdery mildew control.
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Affiliation(s)
- Mo Zhu
- Henan Normal University, 66519, College of Life Sciences, Xinxiang, Henan, China
- Henan Normal University, 66519, Henan International Joint Laboratory of Agricultural Microbial Ecology and Technology, Xinxiang, China;
| | - Jie Ji
- Henan Normal University, 66519, College of Life Sciences, Xinxiang, Henan, China;
| | - Wenqi Shi
- Ministry of Agriculture and Rural Affairs, Key Laboratory of Integrated Pest Management on Crops in Central China, No.18Nanhu Avenue,Hongshan District,Wuhan,HuBei provience, Wuhan, China, 430064
- Hubei Key Laboratory of Crop Disease, Insect Pests and Weeds Control, Wuhan, China;
| | - YongFang Li
- Henan Normal University, 66519, College of Life Sciences, Xinxiang, Henan, China
- Henan Normal University, 66519, Henan International Joint Laboratory of Agricultural Microbial Ecology and Technology, Xinxiang, China;
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11
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Chaloner TM, Gurr SJ, Bebber DP. Geometry and evolution of the ecological niche in plant-associated microbes. Nat Commun 2020; 11:2955. [PMID: 32528123 PMCID: PMC7289842 DOI: 10.1038/s41467-020-16778-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 05/21/2020] [Indexed: 12/17/2022] Open
Abstract
The ecological niche can be thought of as a volume in multidimensional space, where each dimension describes an abiotic condition or biotic resource required by a species. The shape, size, and evolution of this volume strongly determine interactions among species and influence their current and potential geographical distributions, but the geometry of niches is poorly understood. Here, we analyse temperature response functions and host plant ranges for hundreds of potentially destructive plant-associated fungi and oomycetes. We demonstrate that niche specialization is uncorrelated on abiotic (i.e. temperature response) and biotic (i.e. host range) axes, that host interactions restrict fundamental niche breadth to form the realized niche, and that both abiotic and biotic niches show limited phylogenetic constraint. The ecological terms ‘generalist’ and ‘specialist’ therefore do not apply to these microbes, as specialization evolves independently on different niche axes. This adaptability makes plant pathogens a formidable threat to agriculture and forestry. The ecological niche of host-associated microbes is defined by both abiotic and biotic dimensions. Here the authors analyse published data on fungal and oomycete pathogens of plants, demonstrating that specialization can evolve independently on abiotic and biotic axes and that interactions with host plants reduce thermal niche breadth.
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Affiliation(s)
- Thomas M Chaloner
- Department of Biosciences, University of Exeter, Exeter, EX4 4QJ, UK
| | - Sarah J Gurr
- Department of Biosciences, University of Exeter, Exeter, EX4 4QJ, UK.,Department of Biosciences, Utrecht University, Paduallaan, 8, Netherlands
| | - Daniel P Bebber
- Department of Biosciences, University of Exeter, Exeter, EX4 4QJ, UK.
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12
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Evidence for Allele-Specific Levels of Enhanced Susceptibility of Wheat mlo Mutants to the Hemibiotrophic Fungal Pathogen Magnaporthe oryzae pv. Triticum. Genes (Basel) 2020; 11:genes11050517. [PMID: 32392723 PMCID: PMC7720134 DOI: 10.3390/genes11050517] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 04/28/2020] [Accepted: 05/04/2020] [Indexed: 12/11/2022] Open
Abstract
Barley mlo mutants are well known for their profound resistance against powdery mildew disease. Recently, mlo mutant plants were generated in hexaploid bread wheat (Triticum aestivum) with the help of transgenic (transcription-activator-like nuclease, TALEN) and non-transgenic (targeted induced local lesions in genomes, TILLING) biotechnological approaches. While full-gene knockouts in the three wheat Mlo (TaMlo) homoeologs, created via TALEN, confer full resistance to the wheat powdery mildew pathogen (Blumeria graminis f.sp. tritici), the currently available TILLING-derived Tamlo missense mutants provide only partial protection against powdery mildew attack. Here, we studied the infection phenotypes of TALEN- and TILLING-derived Tamlo plants to the two hemibiotrophic pathogens Zymoseptoria tritici, causing Septoria leaf blotch in wheat, and Magnaporthe oryzae pv. Triticum (MoT), the causal agent of wheat blast disease. While Tamlo plants showed unaltered outcomes upon challenge with Z. tritici, we found evidence for allele-specific levels of enhanced susceptibility to MoT, with stronger powdery mildew resistance correlated with more invasive growth by the blast pathogen. Surprisingly, unlike barley mlo mutants, young wheat mlo mutant plants do not show undesired pleiotropic phenotypes such as spontaneous callose deposits in leaf mesophyll cells or signs of early leaf senescence. In conclusion, our study provides evidence for allele-specific levels of enhanced susceptibility of Tamlo plants to the hemibiotrophic wheat pathogen MoT.
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The Parauncinula polyspora Draft Genome Provides Insights into Patterns of Gene Erosion and Genome Expansion in Powdery Mildew Fungi. mBio 2019; 10:mBio.01692-19. [PMID: 31551331 PMCID: PMC6759760 DOI: 10.1128/mbio.01692-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Powdery mildew fungi are widespread and agronomically relevant phytopathogens causing major yield losses. Their genomes have disproportionately large numbers of mobile genetic elements, and they have experienced a significant loss of highly conserved fungal genes. In order to learn more about the evolutionary history of this fungal group, we explored the genome of an Asian oak tree pathogen, Parauncinula polyspora, a species that diverged early during evolution from the remaining powdery mildew fungi. We found that the P. polyspora draft genome is comparatively compact, has a low number of protein-coding genes, and, despite the absence of a dedicated genome defense system, lacks the massive proliferation of repetitive sequences. Based on these findings, we infer an evolutionary trajectory that shaped the genomes of powdery mildew fungi. Due to their comparatively small genome size and short generation time, fungi are exquisite model systems to study eukaryotic genome evolution. Powdery mildew fungi present an exceptional case because of their strict host dependency (termed obligate biotrophy) and the atypical size of their genomes (>100 Mb). This size expansion is largely due to the pervasiveness of transposable elements on 70% of the genome and is associated with the loss of multiple conserved ascomycete genes required for a free-living lifestyle. To date, little is known about the mechanisms that drove these changes, and information on ancestral powdery mildew genomes is lacking. We report genome analysis of the early-diverged and exclusively sexually reproducing powdery mildew fungus Parauncinula polyspora, which we performed on the basis of a natural leaf epiphytic metapopulation sample. In contrast to other sequenced species of this taxonomic group, the assembled P. polyspora draft genome is surprisingly small (<30 Mb), has a higher content of conserved ascomycete genes, and is sparsely equipped with transposons (<10%), despite the conserved absence of a common defense mechanism involved in constraining repetitive elements. We speculate that transposable element spread might have been limited by this pathogen’s unique reproduction strategy and host features and further hypothesize that the loss of conserved ascomycete genes may promote the evolutionary isolation and host niche specialization of powdery mildew fungi. Limitations associated with this evolutionary trajectory might have been in part counteracted by the evolution of plastic, transposon-rich genomes and/or the expansion of gene families encoding secreted virulence proteins.
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Bourras S, Kunz L, Xue M, Praz CR, Müller MC, Kälin C, Schläfli M, Ackermann P, Flückiger S, Parlange F, Menardo F, Schaefer LK, Ben-David R, Roffler S, Oberhaensli S, Widrig V, Lindner S, Isaksson J, Wicker T, Yu D, Keller B. The AvrPm3-Pm3 effector-NLR interactions control both race-specific resistance and host-specificity of cereal mildews on wheat. Nat Commun 2019; 10:2292. [PMID: 31123263 PMCID: PMC6533294 DOI: 10.1038/s41467-019-10274-1] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 05/03/2019] [Indexed: 12/25/2022] Open
Abstract
The wheat Pm3 resistance gene against the powdery mildew pathogen occurs as an allelic series encoding functionally different immune receptors which induce resistance upon recognition of isolate-specific avirulence (AVR) effectors from the pathogen. Here, we describe the identification of five effector proteins from the mildew pathogens of wheat, rye, and the wild grass Dactylis glomerata, specifically recognized by the PM3B, PM3C and PM3D receptors. Together with the earlier identified AVRPM3A2/F2, the recognized AVRs of PM3B/C, (AVRPM3B2/C2), and PM3D (AVRPM3D3) belong to a large group of proteins with low sequence homology but predicted structural similarities. AvrPm3b2/c2 and AvrPm3d3 are conserved in all tested isolates of wheat and rye mildew, and non-host infection assays demonstrate that Pm3b, Pm3c, and Pm3d are also restricting the growth of rye mildew on wheat. Furthermore, divergent AVR homologues from non-adapted rye and Dactylis mildews are recognized by PM3B, PM3C, or PM3D, demonstrating their involvement in host specificity.
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Affiliation(s)
- Salim Bourras
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland.
- Department of Forest Mycology and Plant Pathology, Division of Plant Pathology, Swedish University of Agricultural Sciences, 750 07, Uppsala, Sweden.
| | - Lukas Kunz
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Minfeng Xue
- Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural Sciences, Wuhan, 430064, China
- Ministry of Agriculture Key Laboratory of Integrated Pest Management in Crops in Central China, Wuhan, 430064, China
- College of Life Science, Wuhan University, Wuhan, 430072, China
| | - Coraline Rosalie Praz
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Marion Claudia Müller
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Carol Kälin
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Michael Schläfli
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Patrick Ackermann
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Simon Flückiger
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Francis Parlange
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Fabrizio Menardo
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | | | - Roi Ben-David
- Institute of Plant Science, ARO-Volcani Center, 50250, Bet Dagan, Israel
| | - Stefan Roffler
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Simone Oberhaensli
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Victoria Widrig
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Stefan Lindner
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Jonatan Isaksson
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Thomas Wicker
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Dazhao Yu
- Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural Sciences, Wuhan, 430064, China.
- Ministry of Agriculture Key Laboratory of Integrated Pest Management in Crops in Central China, Wuhan, 430064, China.
- College of Life Science, Wuhan University, Wuhan, 430072, China.
| | - Beat Keller
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland.
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The fungal ribonuclease-like effector protein CSEP0064/BEC1054 represses plant immunity and interferes with degradation of host ribosomal RNA. PLoS Pathog 2019; 15:e1007620. [PMID: 30856238 PMCID: PMC6464244 DOI: 10.1371/journal.ppat.1007620] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 04/15/2019] [Accepted: 02/06/2019] [Indexed: 01/08/2023] Open
Abstract
The biotrophic fungal pathogen Blumeria graminis causes the powdery mildew disease of cereals and grasses. We present the first crystal structure of a B. graminis effector of pathogenicity (CSEP0064/BEC1054), demonstrating it has a ribonuclease (RNase)-like fold. This effector is part of a group of RNase-like proteins (termed RALPHs) which comprise the largest set of secreted effector candidates within the B. graminis genomes. Their exceptional abundance suggests they play crucial functions during pathogenesis. We show that transgenic expression of RALPH CSEP0064/BEC1054 increases susceptibility to infection in both monocotyledonous and dicotyledonous plants. CSEP0064/BEC1054 interacts in planta with the pathogenesis-related protein PR10. The effector protein associates with total RNA and weakly with DNA. Methyl jasmonate (MeJA) levels modulate susceptibility to aniline-induced host RNA fragmentation. In planta expression of CSEP0064/BEC1054 reduces the formation of this RNA fragment. We propose CSEP0064/BEC1054 is a pseudoenzyme that binds to host ribosomes, thereby inhibiting the action of plant ribosome-inactivating proteins (RIPs) that would otherwise lead to host cell death, an unviable interaction and demise of the fungus. Powdery mildews are common plant diseases which affect important crop plants including cereals such as wheat and barley. The fungi that cause this disease are obligate biotrophs: they have an absolute requirement for living host cells which they penetrate with feeding structures called haustoria. These fungi must be highly effective at avoiding immune recognition which would lead to death of the host cell and the pathogen. We assume they do this by delivering effector proteins to the host. While several hundred secreted effectors have been described in cereal powdery mildews, it is unknown how they work. Here, we use X-ray crystallography and nuclear magnetic resonance (NMR) spectroscopy to determine the structure and interactions of the effector CSEP0064/BEC1054, representative of the largest class of effectors resembling fungal RNases. We find that this effector binds nucleic acids. Expression of the effector in plants increases susceptibility to infection. Moreover, transgenic CSEP0064/BEC1054 expression in wheat inhibits the degradation of host ribosomal RNA induced by ribosome-inactivating proteins (RIPs). We propose a novel mechanism of action for the RNase-like effectors in powdery mildews: they may act as pseudoenzymes to inhibit the host RIPs, known components of plant immune responses that lead to host cell death.
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Bourras S, Praz CR, Spanu PD, Keller B. Cereal powdery mildew effectors: a complex toolbox for an obligate pathogen. Curr Opin Microbiol 2018; 46:26-33. [DOI: 10.1016/j.mib.2018.01.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 01/22/2018] [Accepted: 01/31/2018] [Indexed: 01/25/2023]
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17
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Xia C, Wang M, Yin C, Cornejo OE, Hulbert SH, Chen X. Genomic insights into host adaptation between the wheat stripe rust pathogen (Puccinia striiformis f. sp. tritici) and the barley stripe rust pathogen (Puccinia striiformis f. sp. hordei). BMC Genomics 2018; 19:664. [PMID: 30208837 PMCID: PMC6134786 DOI: 10.1186/s12864-018-5041-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Accepted: 08/27/2018] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Plant fungal pathogens can rapidly evolve and adapt to new environmental conditions in response to sudden changes of host populations in agro-ecosystems. However, the genomic basis of their host adaptation, especially at the forma specialis level, remains unclear. RESULTS We sequenced two isolates each representing Puccinia striiformis f. sp. tritici (Pst) and P. striiformis f. sp. hordei (Psh), different formae speciales of the stripe rust fungus P. striiformis highly adapted to wheat and barley, respectively. The divergence of Pst and Psh, estimated to start 8.12 million years ago, has been driven by high nucleotide mutation rates. The high genomic variation within dikaryotic urediniospores of P. striiformis has provided raw genetic materials for genome evolution. No specific gene families have enriched in either isolate, but extensive gene loss events have occurred in both Pst and Psh after the divergence from their most recent common ancestor. A large number of isolate-specific genes were identified, with unique genomic features compared to the conserved genes, including 1) significantly shorter in length; 2) significantly less expressed; 3) significantly closer to transposable elements; and 4) redundant in pathways. The presence of specific genes in one isolate (or forma specialis) was resulted from the loss of the homologues in the other isolate (or forma specialis) by the replacements of transposable elements or losses of genomic fragments. In addition, different patterns and numbers of telomeric repeats were observed between the isolates. CONCLUSIONS Host adaptation of P. striiformis at the forma specialis level is a complex pathogenic trait, involving not only virulence-related genes but also other genes. Gene loss, which might be adaptive and driven by transposable element activities, provides genomic basis for host adaptation of different formae speciales of P. striiformis.
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Affiliation(s)
- Chongjing Xia
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430 USA
| | - Meinan Wang
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430 USA
| | - Chuntao Yin
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430 USA
| | - Omar E. Cornejo
- School of Biological Sciences, Washington State University, Pullman, WA 99164-7520 USA
| | - Scot H. Hulbert
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430 USA
| | - Xianming Chen
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430 USA
- Wheat Health, Genetics, and Quality Research Unit, Agriculture Research Service, U.S. Department of Agriculture, Pullman, WA 99164-6430 USA
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Menardo F, Wicker T, Keller B. Reconstructing the Evolutionary History of Powdery Mildew Lineages (Blumeria graminis) at Different Evolutionary Time Scales with NGS Data. Genome Biol Evol 2018; 9:446-456. [PMID: 28164219 PMCID: PMC5381671 DOI: 10.1093/gbe/evx008] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/30/2017] [Indexed: 01/25/2023] Open
Abstract
Blumeria graminis (Ascomycota) includes fungal pathogens that infect numerous grasses and cereals. Despite its economic impact on agriculture and its scientific importance in plant–pathogen interaction studies, the evolution of different lineages with different host ranges is poorly understood. Moreover, the taxonomy of grass powdery mildew is rather exceptional: there is only one described species (B. graminis) subdivided in different formae speciales (ff.spp.), which are defined by their host range. In this study we applied phylogenomic and population genomic methods to whole genome sequence data of 31 isolates of B. graminis belonging to different ff.spp. and reconstructed the evolutionary relationships between different lineages. The results of the phylogenomic analysis support a pattern of co-evolution between some of the ff.spp. and their host plant. In addition, we identified exceptions to this pattern, namely host jump events and the recent radiation of a clade less than 280,000 years ago. Furthermore, we found a high level of gene tree incongruence localized in the youngest clade. To distinguish between incomplete lineage sorting and lateral gene flow, we applied a coalescent-based method of demographic inference and found evidence of horizontal gene flow between recently diverged lineages. Overall we found that different processes shaped the diversification of B. graminis, co-evolution with the host species, host jump and fast radiation. Our study is an example of how genomic data can resolve complex evolutionary histories of cryptic lineages at different time scales, dealing with incomplete lineage sorting and lateral gene flow.
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Praz CR, Menardo F, Robinson MD, Müller MC, Wicker T, Bourras S, Keller B. Non-parent of Origin Expression of Numerous Effector Genes Indicates a Role of Gene Regulation in Host Adaption of the Hybrid Triticale Powdery Mildew Pathogen. FRONTIERS IN PLANT SCIENCE 2018; 9:49. [PMID: 29441081 PMCID: PMC5797619 DOI: 10.3389/fpls.2018.00049] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 01/10/2018] [Indexed: 05/20/2023]
Abstract
Powdery mildew is an important disease of cereals. It is caused by one species, Blumeria graminis, which is divided into formae speciales each of which is highly specialized to one host. Recently, a new form capable of growing on triticale (B.g. triticale) has emerged through hybridization between wheat and rye mildews (B.g. tritici and B.g. secalis, respectively). In this work, we used RNA sequencing to study the molecular basis of host adaptation in B.g. triticale. We analyzed gene expression in three B.g. tritici isolates, two B.g. secalis isolates and two B.g. triticale isolates and identified a core set of putative effector genes that are highly expressed in all formae speciales. We also found that the genes differentially expressed between isolates of the same form as well as between different formae speciales were enriched in putative effectors. Their coding genes belong to several families including some which contain known members of mildew avirulence (Avr) and suppressor (Svr) genes. Based on these findings we propose that effectors play an important role in host adaptation that is mechanistically based on Avr-Resistance gene-Svr interactions. We also found that gene expression in the B.g. triticale hybrid is mostly conserved with the parent-of-origin, but some genes inherited from B.g. tritici showed a B.g. secalis-like expression. Finally, we identified 11 unambiguous cases of putative effector genes with hybrid-specific, non-parent of origin gene expression, and we propose that they are possible determinants of host specialization in triticale mildew. These data suggest that altered expression of multiple effector genes, in particular Avr and Svr related factors, might play a role in mildew host adaptation based on hybridization.
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Affiliation(s)
- Coraline R. Praz
- Department of Plant and Microbial Biology, University of Zürich, Zürich, Switzerland
| | - Fabrizio Menardo
- Department of Plant and Microbial Biology, University of Zürich, Zürich, Switzerland
| | - Mark D. Robinson
- Department of Molecular Life Sciences and SIB Swiss Institute of Bioinformatics, University of Zürich, Zürich, Switzerland
| | - Marion C. Müller
- Department of Plant and Microbial Biology, University of Zürich, Zürich, Switzerland
| | - Thomas Wicker
- Department of Plant and Microbial Biology, University of Zürich, Zürich, Switzerland
| | - Salim Bourras
- Department of Plant and Microbial Biology, University of Zürich, Zürich, Switzerland
- *Correspondence: Salim Bourras
| | - Beat Keller
- Department of Plant and Microbial Biology, University of Zürich, Zürich, Switzerland
- Beat Keller
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Menardo F, Praz CR, Wicker T, Keller B. Rapid turnover of effectors in grass powdery mildew (Blumeria graminis). BMC Evol Biol 2017; 17:223. [PMID: 29089018 PMCID: PMC5664452 DOI: 10.1186/s12862-017-1064-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 10/02/2017] [Indexed: 11/21/2022] Open
Abstract
Background Grass powdery mildew (Blumeria graminis, Ascomycota) is a major pathogen of cereal crops and has become a model organism for obligate biotrophic fungal pathogens of plants. The sequenced genomes of two formae speciales (ff.spp.), B.g. hordei and B.g. tritici (pathogens of barley and wheat), were found to be enriched in candidate effector genes (CEGs). Similar to other filamentous pathogens, CEGs in B. graminis are under positive selection. Additionally, effectors are more likely to have presence-absence polymorphisms than other genes among different strains. Results Here we identified effectors in the genomes of three additional host-specific lineages of B. graminis (B.g. poae, B.g. avenae and B.g. infecting Lolium) which diverged between 24 and 5 million years ago (Mya). We found that most CEGs in B. graminis are clustered in families and that most families are present in both reference genomes (B.g. hordei and B.g. tritici) and in the genomes of all three newly annotated lineages. We identified conserved protein domains including a novel lipid binding domain. The phylogenetic analysis showed that frequent gene duplications and losses shaped the diversity of the effector repertoires of the different lineages through their evolutionary history. We observed several lineage-specific expansions where large clades of CEGs originated in only one lineage from a single gene through repeated gene duplications. When we applied a birth-death model we found that the turnover rate (the rate at which genes are deleted and duplicated) of CEG families is much higher than for non-CEG families. The analysis of genomic context revealed that the immediate surroundings of CEGs are enriched in transposable elements (TE) which could play a role in the duplication and deletion of CEGs. Conclusions The CEG repertoires of related pathogens diverged dramatically in short evolutionary times because of rapid turnover and of positive selection fixing non-synonymous mutations. While signatures of positive selection on effector sequences are the expected outcome of the evolutionary “arms race” between pathogen and plant immune system, it is more difficult to infer the mechanisms and evolutionary forces that maintained an extreme turnover rate in CEG families of B. graminis for several millions of years. Electronic supplementary material The online version of this article (10.1186/s12862-017-1064-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Fabrizio Menardo
- Department of Plant and Microbial Biology, University of Zürich, Zollikerstrasse 107, 8008, Zürich, Switzerland
| | - Coraline R Praz
- Department of Plant and Microbial Biology, University of Zürich, Zollikerstrasse 107, 8008, Zürich, Switzerland
| | - Thomas Wicker
- Department of Plant and Microbial Biology, University of Zürich, Zollikerstrasse 107, 8008, Zürich, Switzerland.
| | - Beat Keller
- Department of Plant and Microbial Biology, University of Zürich, Zollikerstrasse 107, 8008, Zürich, Switzerland.
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Desprez-Loustau ML, Massot M, Feau N, Fort T, de Vicente A, Torés JA, Ortuño DF. Further Support of Conspecificity of Oak and Mango Powdery Mildew and First Report of Erysiphe quercicola and Erysiphe alphitoides on Mango in Mainland Europe. PLANT DISEASE 2017; 101:1086-1093. [PMID: 30682963 DOI: 10.1094/pdis-01-17-0116-re] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Mango leaves and inflorescences infected by powdery mildew in southern Spain were analyzed using multigene sequencing (ITS + 4 single-copy coding genes) to identify the causal agent. Erysiphe quercicola was detected in 97% out of 140 samples, collected in six different orchards in the Malaga region. Among these, a small proportion also yielded E. alphitoides (8% of all samples) and E. alphitoides was found alone in 3% of samples. A phylogenetic approach was completed by cross inoculations between oak and mango, which led to typical symptoms, supporting the conspecificity of oak and mango powdery mildews. To our knowledge, this is the first report of E. quercicola and E. alphitoides causing powdery mildew on mango trees in mainland Spain, and thus mainland Europe, based on unequivocal phylogenetic and biological evidence. Our study thus confirmed the broad host range of both E. quercicola and E. alphitoides. These results have practical implications in terms of the demonstrated ability for host range expansion in powdery mildews. They also open interesting prospects to the elucidation of molecular mechanisms underlying the ability to infect single versus multiple and unrelated host plants since these two closely related powdery mildew species belong to a small clade with both generalist and specialist powdery mildews.
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Affiliation(s)
| | - Marie Massot
- UMR 1202 BIOGECO, INRA, Univ Bordeaux, 33610 Cestas, France
| | - Nicolas Feau
- Department of Forest and Conservation Sciences, British Columbia, The University of British Columbia, Vancouver, V6T 1Z4, Canada
| | - Tania Fort
- UMR 1202 BIOGECO, INRA, Univ Bordeaux, 33610 Cestas, France
| | - Antonio de Vicente
- Instituto de Horticultura Subtropical y Mediterránea La Mayora (IHSM-UMA-CSIC), Departamento de Microbiología, Facultad de Ciencias, 29071, Málaga, Spain
| | - Juan Antonio Torés
- Instituto de Horticultura Subtropical y Mediterránea La Mayora (IHSM-UMA-CSIC), Algarrobo-Costa, 29750, Málaga, Spain
| | - Dolores Fernández Ortuño
- Instituto de Horticultura Subtropical y Mediterránea La Mayora (IHSM-UMA-CSIC), Departamento de Microbiología, Facultad de Ciencias, 29071, Málaga, Spain; and Instituto de Horticultura Subtropical y Mediterránea La Mayora (IHSM-UMA-CSIC), Algarrobo-Costa, 29750, Málaga, Spain
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22
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Abstract
Fungal plant pathogens are ubiquitous and highly diverse. Key to their success is high host density, which notably is the case in agroecosystems. Several hypotheses related to the effects of plant pathogens on plant diversity (the Janzen-Connell hypothesis, the dilution effect hypothesis) and the phenomenon of higher biomass in plant mixtures (i.e., overyielding) can all be explained by the quantitative interplay between host and pathogen density. In many agroecosystems, fungal plant pathogens cause great losses, since in monocultures diseased plants cannot be replaced by healthy plants. On the other hand, in natural ecosystems fungal plant pathogens shape the succession of vegetation and enhance the biodiversity of forests and grasslands. When pathogens are introduced into areas outside their natural range, they may behave differently, causing severe damage. Once introduced, changes may occur such as hybridization with other closely related pathogens or host shifts, host jumps, or horizontal gene transfer. Such changes can be hazardous for both agricultural and natural ecosystems.
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23
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El-Hossary EM, Cheng C, Hamed MM, El-Sayed Hamed AN, Ohlsen K, Hentschel U, Abdelmohsen UR. Antifungal potential of marine natural products. Eur J Med Chem 2016; 126:631-651. [PMID: 27936443 DOI: 10.1016/j.ejmech.2016.11.022] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 11/07/2016] [Accepted: 11/10/2016] [Indexed: 12/29/2022]
Abstract
Fungal diseases represent an increasing threat to human health worldwide which in some cases might be associated with substantial morbidity and mortality. However, only few antifungal drugs are currently available for the treatment of life-threatening fungal infections. Furthermore, plant diseases caused by fungal pathogens represent a worldwide economic problem for the agriculture industry. The marine environment continues to provide structurally diverse and biologically active secondary metabolites, several of which have inspired the development of new classes of therapeutic agents. Among these secondary metabolites, several compounds with noteworthy antifungal activities have been isolated from marine microorganisms, invertebrates, and algae. During the last fifteen years, around 65% of marine natural products possessing antifungal activities have been isolated from sponges and bacteria. This review gives an overview of natural products from diverse marine organisms that have shown in vitro and/or in vivo potential as antifungal agents, with their mechanism of action whenever applicable. The natural products literature is covered from January 2000 until June 2015, and we are reporting the chemical structures together with their biological activities, as well as the isolation source.
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Affiliation(s)
- Ebaa M El-Hossary
- National Centre for Radiation Research & Technology, Egyptian Atomic Energy Authority, Ahmed El-Zomor St. 3, El-Zohoor Dist., Nasr City, Cairo, Egypt
| | - Cheng Cheng
- Department of Botany II, Julius-von-Sachs Institute for Biological Sciences, University of Würzburg, Julius-von-Sachs-Platz 3, 97082 Würzburg, Germany
| | - Mostafa M Hamed
- Drug Design and Optimization Department, Helmholtz Institute for Pharmaceutical Research Saarland, Saarland University, Campus E8.1, 66123 Saarbrücken, Germany
| | | | - Knut Ohlsen
- Institute for Molecular Infection Biology, University of Würzburg, Josef-Schneider-Straße 2/D15, 97080 Würzburg, Germany
| | - Ute Hentschel
- GEOMAR Helmholtz Centre for Ocean Research, RD3 Marine Microbiology, and Christian-Albrechts University of Kiel, Düsternbrooker Weg 20, 24105 Kiel, Germany
| | - Usama Ramadan Abdelmohsen
- Department of Botany II, Julius-von-Sachs Institute for Biological Sciences, University of Würzburg, Julius-von-Sachs-Platz 3, 97082 Würzburg, Germany; Department of Pharmacognosy, Faculty of Pharmacy, Minia University, 61519 Minia, Egypt.
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24
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Ben-David R, Parks R, Dinoor A, Kosman E, Wicker T, Keller B, Cowger C. Differentiation Among Blumeria graminis f. sp. tritici Isolates Originating from Wild Versus Domesticated Triticum Species in Israel. PHYTOPATHOLOGY 2016; 106:861-870. [PMID: 27019062 DOI: 10.1094/phyto-07-15-0177-r] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Israel and its vicinity constitute a center of diversity of domesticated wheat species (Triticum aestivum and T. durum) and their sympatrically growing wild relatives, including wild emmer wheat (T. dicoccoides). We investigated differentiation within the forma specialis of their obligate powdery mildew pathogen, Blumeria graminis f. sp. tritici. A total of 61 B. graminis f. sp. tritici isolates were collected from the three host species in four geographic regions of Israel. Genetic relatedness of the isolates was characterized using both virulence patterns on 38 wheat lines (including 21 resistance gene differentials) and presumptively neutral molecular markers (simple-sequence repeats and single-nucleotide polymorphisms). All isolates were virulent on at least some genotypes of all three wheat species tested. All assays divided the B. graminis f. sp. tritici collection into two distinct groups, those from domesticated hosts and those from wild emmer wheat. One-way migration was detected from the domestic wheat B. graminis f. sp. tritici population to the wild emmer B. graminis f. sp. tritici population at a rate of five to six migrants per generation. This gene flow may help explain the overlap between the distinct domestic and wild B. graminis f. sp. tritici groups. Overall, B. graminis f. sp. tritici is significantly differentiated into wild-emmer and domesticated-wheat populations, although the results do not support the existence of a separate f. sp. dicocci.
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Affiliation(s)
- Roi Ben-David
- First author: Department of Vegetables and Field Crops, Institute of Plant Sciences, ARO-Volcani Center, Bet Dagan 5025000, Israel; second and seventh authors: United States Department of Agriculture-Agricultural Research Service, Department of Plant Pathology, North Carolina State University, Raleigh 27695; third author: The Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel; fourth author: Institute for Cereal Crops Improvement (ICCI), The George S. Wise Faculty for Life Sciences Tel Aviv University, Tel Aviv 69978, Israel; and fifth and sixth authors: Department of Plant and Microbial Biology, University of Zurich, Zollikerstrasse 107, CH-8008 Zurich, Switzerland
| | - Ryan Parks
- First author: Department of Vegetables and Field Crops, Institute of Plant Sciences, ARO-Volcani Center, Bet Dagan 5025000, Israel; second and seventh authors: United States Department of Agriculture-Agricultural Research Service, Department of Plant Pathology, North Carolina State University, Raleigh 27695; third author: The Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel; fourth author: Institute for Cereal Crops Improvement (ICCI), The George S. Wise Faculty for Life Sciences Tel Aviv University, Tel Aviv 69978, Israel; and fifth and sixth authors: Department of Plant and Microbial Biology, University of Zurich, Zollikerstrasse 107, CH-8008 Zurich, Switzerland
| | - Amos Dinoor
- First author: Department of Vegetables and Field Crops, Institute of Plant Sciences, ARO-Volcani Center, Bet Dagan 5025000, Israel; second and seventh authors: United States Department of Agriculture-Agricultural Research Service, Department of Plant Pathology, North Carolina State University, Raleigh 27695; third author: The Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel; fourth author: Institute for Cereal Crops Improvement (ICCI), The George S. Wise Faculty for Life Sciences Tel Aviv University, Tel Aviv 69978, Israel; and fifth and sixth authors: Department of Plant and Microbial Biology, University of Zurich, Zollikerstrasse 107, CH-8008 Zurich, Switzerland
| | - Evsey Kosman
- First author: Department of Vegetables and Field Crops, Institute of Plant Sciences, ARO-Volcani Center, Bet Dagan 5025000, Israel; second and seventh authors: United States Department of Agriculture-Agricultural Research Service, Department of Plant Pathology, North Carolina State University, Raleigh 27695; third author: The Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel; fourth author: Institute for Cereal Crops Improvement (ICCI), The George S. Wise Faculty for Life Sciences Tel Aviv University, Tel Aviv 69978, Israel; and fifth and sixth authors: Department of Plant and Microbial Biology, University of Zurich, Zollikerstrasse 107, CH-8008 Zurich, Switzerland
| | - Thomas Wicker
- First author: Department of Vegetables and Field Crops, Institute of Plant Sciences, ARO-Volcani Center, Bet Dagan 5025000, Israel; second and seventh authors: United States Department of Agriculture-Agricultural Research Service, Department of Plant Pathology, North Carolina State University, Raleigh 27695; third author: The Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel; fourth author: Institute for Cereal Crops Improvement (ICCI), The George S. Wise Faculty for Life Sciences Tel Aviv University, Tel Aviv 69978, Israel; and fifth and sixth authors: Department of Plant and Microbial Biology, University of Zurich, Zollikerstrasse 107, CH-8008 Zurich, Switzerland
| | - Beat Keller
- First author: Department of Vegetables and Field Crops, Institute of Plant Sciences, ARO-Volcani Center, Bet Dagan 5025000, Israel; second and seventh authors: United States Department of Agriculture-Agricultural Research Service, Department of Plant Pathology, North Carolina State University, Raleigh 27695; third author: The Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel; fourth author: Institute for Cereal Crops Improvement (ICCI), The George S. Wise Faculty for Life Sciences Tel Aviv University, Tel Aviv 69978, Israel; and fifth and sixth authors: Department of Plant and Microbial Biology, University of Zurich, Zollikerstrasse 107, CH-8008 Zurich, Switzerland
| | - Christina Cowger
- First author: Department of Vegetables and Field Crops, Institute of Plant Sciences, ARO-Volcani Center, Bet Dagan 5025000, Israel; second and seventh authors: United States Department of Agriculture-Agricultural Research Service, Department of Plant Pathology, North Carolina State University, Raleigh 27695; third author: The Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel; fourth author: Institute for Cereal Crops Improvement (ICCI), The George S. Wise Faculty for Life Sciences Tel Aviv University, Tel Aviv 69978, Israel; and fifth and sixth authors: Department of Plant and Microbial Biology, University of Zurich, Zollikerstrasse 107, CH-8008 Zurich, Switzerland
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25
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Pennington HG, Li L, Spanu PD. Identification and selection of normalization controls for quantitative transcript analysis in Blumeria graminis. MOLECULAR PLANT PATHOLOGY 2016; 17:625-33. [PMID: 26238194 PMCID: PMC5102671 DOI: 10.1111/mpp.12300] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The investigation of obligate biotrophic pathogens, for example Blumeria graminis, presents a number of challenges. The sensitivity of many assays is reduced because of the presence of host material. Furthermore, the fungal structures inside and outside of the plant possess very different characteristics. Normalization genes are used in quantitative real-time polymerase chain reaction (qPCR) to compensate for changes as a result of the quantity and quality of template material. Such genes are used as references against which genes of interest are compared, enabling true quantification. Here, we identified six potential B. graminis and five barley genes for qPCR normalization. The relative changes in abundance of the transcripts were assayed across an infection time course in barley epidermis, in B. graminis epiphytic structures and haustoria. The B. graminis glyceraldehyde-3-phosphate dehydrogenase (GAPDH), actin (ACT) and histone 3 (H3) genes and the barley GAPDH, ubiquitin (UBI) and α-tubulin 2B (TUBA2B) genes were optimal normalization controls for qPCR during the infection cycle. These genes were then used for normalization in the quantification of the members of a Candidate Secreted Effector Protein (CSEP) family 21, a conidia-specific gene and barley genes encoding putative interactors of CSEP0064. The analysis demonstrates the importance of identifying which reference genes are appropriate for each investigation.
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Affiliation(s)
- Helen G Pennington
- Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK
| | - Linhan Li
- Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK
| | - Pietro D Spanu
- Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK
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26
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Cowger C, Parks R, Kosman E. Structure and Migration in U.S. Blumeria graminis f. sp. tritici Populations. PHYTOPATHOLOGY 2016; 106:295-304. [PMID: 26623997 DOI: 10.1094/phyto-03-15-0066-r] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
While wheat powdery mildew occurs throughout the south-central and eastern United States, epidemics are especially damaging in the Mid-Atlantic states. The structure of the U.S. Blumeria graminis f. sp. tritici population was assessed based on a sample of 238 single-spored isolates. The isolates were collected from 16 locations in 12 states (18 site-years) as chasmothecial samples in 2003 or 2005, or as conidial samples in 2007 or 2010. DNA was evaluated using nine single nucleotide polymorphism (SNP) markers in four housekeeping genes, and 10 simple sequence repeat (SSR) markers. The SSR markers were variably polymorphic, with allele numbers ranging from 3 to 39 per locus. Genotypic diversity was high (210 haplotypes) and in eight of the site-years, every isolate had a different SSR genotype. SNP haplotypic diversity was lower; although 15 haplotypes were identified, the majority of isolates possessed one of two haplotypes. The chasmothecial samples showed no evidence of linkage disequilibrium (P = 0.36), while the conidial samples did (P = 0.001), but the two groups had nearly identical mean levels of genetic diversity, which was moderate. There was a weakly positive relationship between genetic distance and geographic distance (R(2) = 0.25, P = 0.001), indicating modest isolation by distance. Most locations in the Mid-Atlantic and Great Lakes regions clustered together genetically, while Southeast locations formed a distinct but adjacent cluster; all of these were genetically separated from Southern Plains locations and an intermediate location in Kentucky. One-way migration was detected at a rate of approximately five individuals per generation from populations west of the Appalachian Mountains to those to the east, despite the fact that the Atlantic states experience more frequent and damaging wheat mildew epidemics. Overall, the evidence argues for a large-scale mosaic of overlapping populations that re-establish themselves from local sources, rather than continental-scale extinction and re-establishment, and a low rate of long-distance dispersal roughly from west to east, consistent with prevailing wind directions.
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Affiliation(s)
- Christina Cowger
- First and second author: U.S. Department of Agriculture-Agricultural Research Service, CB7616, Department of Plant Pathology, North Carolina State University, Raleigh 27695; and third author: Faculty of Life Sciences, Institute for Cereal Crops Improvement, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ryan Parks
- First and second author: U.S. Department of Agriculture-Agricultural Research Service, CB7616, Department of Plant Pathology, North Carolina State University, Raleigh 27695; and third author: Faculty of Life Sciences, Institute for Cereal Crops Improvement, Tel Aviv University, Tel Aviv 69978, Israel
| | - Evsey Kosman
- First and second author: U.S. Department of Agriculture-Agricultural Research Service, CB7616, Department of Plant Pathology, North Carolina State University, Raleigh 27695; and third author: Faculty of Life Sciences, Institute for Cereal Crops Improvement, Tel Aviv University, Tel Aviv 69978, Israel
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27
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Amselem J, Vigouroux M, Oberhaensli S, Brown JKM, Bindschedler LV, Skamnioti P, Wicker T, Spanu PD, Quesneville H, Sacristán S. Evolution of the EKA family of powdery mildew avirulence-effector genes from the ORF 1 of a LINE retrotransposon. BMC Genomics 2015; 16:917. [PMID: 26556056 PMCID: PMC4641428 DOI: 10.1186/s12864-015-2185-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Accepted: 11/03/2015] [Indexed: 12/31/2022] Open
Abstract
Background The Avrk1 and Avra10 avirulence (AVR) genes encode effectors that increase the pathogenicity of the fungus Blumeria graminis f.sp. hordei (Bgh), the powdery mildew pathogen, in susceptible barley plants. In resistant barley, MLK1 and MLA10 resistance proteins recognize the presence of AVRK1 and AVRA10, eliciting the hypersensitive response typical of gene for gene interactions. Avrk1 and Avra10 have more than 1350 homologues in Bgh genome, forming the EKA (Effectors homologous to Avrk1 and Avra10) gene family. Results We tested the hypothesis that the EKA family originated from degenerate copies of Class I LINE retrotransposons by analysing the EKA family in the genome of Bgh isolate DH14 with bioinformatic tools specially developed for the analysis of Transposable Elements (TE) in genomes. The Class I LINE retrotransposon copies homologous to Avrk1 and Avra10 represent 6.5 % of the Bgh annotated genome and, among them, we identified 293 AVR/effector candidate genes. We also experimentally identified peptides that indicated the translation of several predicted proteins from EKA family members, which had higher relative abundance in haustoria than in hyphae. Conclusions Our analyses indicate that Avrk1 and Avra10 have evolved from part of the ORF1 gene of Class I LINE retrotransposons. The co-option of Avra10 and Avrk1 as effectors from truncated copies of retrotransposons explains the huge number of homologues in Bgh genome that could act as dynamic reservoirs from which new effector genes may evolve. These data provide further evidence for recruitment of retrotransposons in the evolution of new biological functions. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-2185-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Joelle Amselem
- INRA, UR1164 URGI Unité de Recherche Génomique-Info, Institut National de la Recherche Agronomique de Versailles-Grignon, Versailles, 78026, France. .,INRA, UR1290 BIOGER, Biologie et gestion des risques en agriculture, Campus AgroParisTech, 78850, Thiverval-Grignon, France.
| | | | - Simone Oberhaensli
- Institute of Plant Biology, University of Zurich, Zollikerstrasse 107, 8008, Zurich, Switzerland.
| | - James K M Brown
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.
| | | | - Pari Skamnioti
- Laboratory of Genetics, Department of Biotechnology, Agricultural University of Athens, Iera Odos 75, TK 11855, Athens, Greece.
| | - Thomas Wicker
- Institute of Plant Biology, University of Zurich, Zollikerstrasse 107, 8008, Zurich, Switzerland.
| | - Pietro D Spanu
- Department of Life Sciences, Imperial College London, London, UK.
| | - Hadi Quesneville
- INRA, UR1164 URGI Unité de Recherche Génomique-Info, Institut National de la Recherche Agronomique de Versailles-Grignon, Versailles, 78026, France.
| | - Soledad Sacristán
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA) and E.T.S.I. Agrónomos, Universidad Politécnica de Madrid, Campus de Montegancedo, Pozuelo de Alarcón, 28223, Madrid, Spain.
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28
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Genetic and molecular characterization of a locus involved in avirulence of Blumeria graminis f. sp. tritici on wheat Pm3 resistance alleles. Fungal Genet Biol 2015; 82:181-92. [DOI: 10.1016/j.fgb.2015.06.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 05/10/2015] [Accepted: 06/09/2015] [Indexed: 01/26/2023]
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29
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Jankovics T, Komáromi J, Fábián A, Jäger K, Vida G, Kiss L. New Insights into the Life Cycle of the Wheat Powdery Mildew: Direct Observation of Ascosporic Infection in Blumeria graminis f. sp. tritici. PHYTOPATHOLOGY 2015; 105:797-804. [PMID: 25710203 DOI: 10.1094/phyto-10-14-0268-r] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Although Blumeria graminis is an intensively studied pathogen, an important part of its life cycle (namely, the way ascospores initiate primary infections on cereal leaves) has not yet been explored in detail. This study reports, for the first time, the direct observation of this process in B. graminis f. sp. tritici using light and confocal laser-scanning microscopy. All the germinated ascospores produced a single germ tube type both in vitro and on host plant surfaces; therefore, the ascosporic and conidial germination patterns are markedly different in this fungus, in contrast to other powdery mildews. Germinated ascospores penetrated the epidermal cells of wheat leaves and produced haustoria as known in the case of conidial infections. This work confirmed earlier studies reporting that B. graminis chasmothecia collected from the field do not contain mature ascospores, only asci filled with protoplasm; ascospore development is induced by moist conditions and is a fast process compared with other powdery mildews. Although ascosporic infections are frequent in B. graminis f. sp. tritici in the field, as shown by this study and other works as well, a recent analysis of the genomes of four isolates revealed the signs of clonal or near-clonal reproduction. Therefore, chasmothecia and ascospores are probably more important as oversummering structures than genetic recombination factors in the life cycle of this pathogen.
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Affiliation(s)
- Tünde Jankovics
- First and sixth authors: Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences (MTA), P.O. Box 102, H-1525 Budapest, Hungary; second, third, fourth, and fifth authors: Agricultural Institute, Centre for Agricultural Research, MTA, Brunszvik 2, H-2462 Martonvásár, Hungary; and sixth author: University of Pannonia, Georgikon Faculty, Institute of Plant Protection, Deák Ferenc u. 57, H-8360 Keszthely, Hungary
| | - Judit Komáromi
- First and sixth authors: Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences (MTA), P.O. Box 102, H-1525 Budapest, Hungary; second, third, fourth, and fifth authors: Agricultural Institute, Centre for Agricultural Research, MTA, Brunszvik 2, H-2462 Martonvásár, Hungary; and sixth author: University of Pannonia, Georgikon Faculty, Institute of Plant Protection, Deák Ferenc u. 57, H-8360 Keszthely, Hungary
| | - Attila Fábián
- First and sixth authors: Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences (MTA), P.O. Box 102, H-1525 Budapest, Hungary; second, third, fourth, and fifth authors: Agricultural Institute, Centre for Agricultural Research, MTA, Brunszvik 2, H-2462 Martonvásár, Hungary; and sixth author: University of Pannonia, Georgikon Faculty, Institute of Plant Protection, Deák Ferenc u. 57, H-8360 Keszthely, Hungary
| | - Katalin Jäger
- First and sixth authors: Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences (MTA), P.O. Box 102, H-1525 Budapest, Hungary; second, third, fourth, and fifth authors: Agricultural Institute, Centre for Agricultural Research, MTA, Brunszvik 2, H-2462 Martonvásár, Hungary; and sixth author: University of Pannonia, Georgikon Faculty, Institute of Plant Protection, Deák Ferenc u. 57, H-8360 Keszthely, Hungary
| | - Gyula Vida
- First and sixth authors: Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences (MTA), P.O. Box 102, H-1525 Budapest, Hungary; second, third, fourth, and fifth authors: Agricultural Institute, Centre for Agricultural Research, MTA, Brunszvik 2, H-2462 Martonvásár, Hungary; and sixth author: University of Pannonia, Georgikon Faculty, Institute of Plant Protection, Deák Ferenc u. 57, H-8360 Keszthely, Hungary
| | - Levente Kiss
- First and sixth authors: Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences (MTA), P.O. Box 102, H-1525 Budapest, Hungary; second, third, fourth, and fifth authors: Agricultural Institute, Centre for Agricultural Research, MTA, Brunszvik 2, H-2462 Martonvásár, Hungary; and sixth author: University of Pannonia, Georgikon Faculty, Institute of Plant Protection, Deák Ferenc u. 57, H-8360 Keszthely, Hungary
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Affiliation(s)
- Ralph Panstruga
- Unit of Plant Cell Biology, RWTH Aachen University, Worringerweg, 1, 52074, Aachen, Germany
| | - Pietro D Spanu
- Department of Life Sciences, Imperial College London, Imperial College Road, London, SW7 2AZ, UK
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