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Bernasconi Z, Stirnemann U, Heuberger M, Sotiropoulos AG, Graf J, Wicker T, Keller B, Sánchez-Martín J. Mutagenesis of Wheat Powdery Mildew Reveals a Single Gene Controlling Both NLR and Tandem Kinase-Mediated Immunity. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2024; 37:264-276. [PMID: 37934013 DOI: 10.1094/mpmi-09-23-0136-fi] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2023]
Abstract
Blumeria graminis f. sp. tritici (Bgt) is a globally important fungal wheat pathogen. Some wheat genotypes contain powdery mildew resistance (Pm) genes encoding immune receptors that recognize specific fungal-secreted effector proteins, defined as avirulence (Avr) factors. Identifying Avr factors is vital for understanding the mechanisms, functioning, and durability of wheat resistance. Here, we present AvrXpose, an approach to identify Avr genes in Bgt by generating gain-of-virulence mutants on Pm genes. We first identified six Bgt mutants with gain of virulence on Pm3b and Pm3c. They all had point mutations, deletions or insertions of transposable elements within the corresponding AvrPm3b2/c2 gene or its promoter region. We further selected six mutants on Pm3a, aiming to identify the yet unknown AvrPm3a3 recognized by Pm3a, in addition to the previously described AvrPm3a2/f2. Surprisingly, Pm3a virulence in the obtained mutants was always accompanied by an additional gain of virulence on the unrelated tandem kinase resistance gene WTK4. No virulence toward 11 additional R genes tested was observed, indicating that the gain of virulence was specific for Pm3a and WTK4. Several independently obtained Pm3a-WTK4 mutants have mutations in Bgt-646, a gene encoding a putative, nonsecreted ankyrin repeat-containing protein. Gene expression analysis suggests that Bgt-646 regulates a subset of effector genes. We conclude that Bgt-646 is a common factor required for avirulence on both a specific nucleotide-binding leucine-rich repeat and a WTK immune receptor. Our findings suggest that, beyond effectors, another type of pathogen protein can control the race-specific interaction between powdery mildew and wheat. [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)
- Zoe Bernasconi
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Ursin Stirnemann
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Matthias Heuberger
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Alexandros G Sotiropoulos
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
- Centre for Crop Health, University of Southern Queensland, Darling Heights, Queensland, Australia
| | - Johannes Graf
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Thomas Wicker
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Beat Keller
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Javier Sánchez-Martín
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
- Department of Microbiology and Genetics, Spanish-Portuguese Agricultural Research Centre (CIALE), University of Salamanca, Salamanca, Spain
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Li Y, Dai J, Zhang T, Wang B, Zhang S, Wang C, Zhang J, Yao Q, Li M, Li C, Peng Y, Cao S, Zhan G, Tao F, Gao H, Huang W, Feng X, Bai Y, Qucuo Z, Shang H, Huang C, Liu W, Zhan J, Xu X, Chen X, Kang Z, Hu X. Genomic analysis, trajectory tracking, and field surveys reveal sources and long-distance dispersal routes of wheat stripe rust pathogen in China. PLANT COMMUNICATIONS 2023:100563. [PMID: 36809881 PMCID: PMC10363508 DOI: 10.1016/j.xplc.2023.100563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 01/08/2023] [Accepted: 02/17/2023] [Indexed: 06/18/2023]
Abstract
Identifying sources of phytopathogen inoculum and determining their contributions to disease outbreaks are essential for predicting disease development and establishing control strategies. Puccinia striiformis f. sp. tritici (Pst), the causal agent of wheat stripe rust, is an airborne fungal pathogen with rapid virulence variation that threatens wheat production through its long-distance migration. Because of wide variation in geographic features, climatic conditions, and wheat production systems, Pst sources and related dispersal routes in China are largely unclear. In the present study, we performed genomic analyses of 154 Pst isolates from all major wheat-growing regions in China to determine Pst population structure and diversity. Through trajectory tracking, historical migration studies, genetic introgression analyses, and field surveys, we investigated Pst sources and their contributions to wheat stripe rust epidemics. We identified Longnan, the Himalayan region, and the Guizhou Plateau, which contain the highest population genetic diversities, as the Pst sources in China. Pst from Longnan disseminates mainly to eastern Liupan Mountain, the Sichuan Basin, and eastern Qinghai; that from the Himalayan region spreads mainly to the Sichuan Basin and eastern Qinghai; and that from the Guizhou Plateau migrates mainly to the Sichuan Basin and the Central Plain. These findings improve our current understanding of wheat stripe rust epidemics in China and emphasize the need for managing stripe rust on a national scale.
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Affiliation(s)
- Yuxiang Li
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Taicheng Road 3, Yangling, Shaanxi, China
| | - Jichen Dai
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Taicheng Road 3, Yangling, Shaanxi, China
| | - Taixue Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Taicheng Road 3, Yangling, Shaanxi, China
| | - Baotong Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Taicheng Road 3, Yangling, Shaanxi, China
| | - Siyue Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Taicheng Road 3, Yangling, Shaanxi, China
| | - Conghao Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Taicheng Road 3, Yangling, Shaanxi, China
| | - Jiguang Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Taicheng Road 3, Yangling, Shaanxi, China
| | - Qiang Yao
- Key Laboratory of Agricultural Integrated Pest Management, Qinghai Province, Academy of Agriculture and Forestry Science, Qinghai University, Xining, Qinghai, China
| | - Mingju Li
- Yunnan Key Laboratory of Green Prevention and Control of Agricultural Transboundary Pests, Agricultural Environment and Resource Institute, Yunnan Academy of Agricultural Sciences, Kunming, Yunnan, China
| | - Chengyun Li
- State Key Laboratory for Conservation and Utilization of Bio-resources in Yunnan, Yunnan Agricultural University, Kunming, Yunnan, China
| | - Yuelin Peng
- Department of Plant Pathology, Tibet Agricultural and Animal Husbandry College, Linzhi, Tibet, China
| | - Shiqin Cao
- Wheat Research Institute, Gansu Academy of Agricultural Sciences, Lanzhou, Gansu, China
| | - Gangming Zhan
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Taicheng Road 3, Yangling, Shaanxi, China
| | - Fei Tao
- Biocontrol Engineering Laboratory of Crop Diseases and Pests of Gansu Province, College of Plant Protection, Gansu Agricultural University, Lanzhou, Gansu, China
| | - Haifeng Gao
- Institute of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi, Xinjiang, China
| | - Weili Huang
- Xi'an Huang's Bio-technology Company Ltd, Xi'an, Shaanxi, China
| | - Xiaojun Feng
- Shaanxi Plant Protection Extension Station, Xi'an, Shaanxi, China
| | - Yingwen Bai
- Baoji Plant Protection Extension Station, Baoji, Shaanxi, China
| | - Zhuoma Qucuo
- Department of Plant Pathology, Tibet Agricultural and Animal Husbandry College, Linzhi, Tibet, China
| | - Hongsheng Shang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Taicheng Road 3, Yangling, Shaanxi, China
| | - Chong Huang
- National Agricultural Technology Extension and Service Center, Ministry of Agriculture, Beijing, China
| | - Wancai Liu
- National Agricultural Technology Extension and Service Center, Ministry of Agriculture, Beijing, China
| | - Jiasui Zhan
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Xiangming Xu
- Pest & Pathogen Ecology, NIAB EMR, East Malling, West Malling, Kent, UK
| | - Xianming Chen
- Agricultural Research Service, United States Department of Agriculture and Department of Plant Pathology, Washington State University, Pullman, WA, USA
| | - Zhensheng Kang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Taicheng Road 3, Yangling, Shaanxi, China.
| | - Xiaoping Hu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Taicheng Road 3, Yangling, Shaanxi, China.
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Li Y, Liu L, Wang M, Ruff T, See DR, Hu X, Chen X. Characterization and Molecular Mapping of a Gene Conferring High-Temperature Adult-Plant Resistance to Stripe Rust Originally from Aegilops ventricosa. PLANT DISEASE 2023; 107:431-442. [PMID: 35852900 DOI: 10.1094/pdis-06-22-1419-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Wheat near-isogenic line AvSYr17NIL carrying Yr17, originally from Aegilops ventricosa for all-stage resistance to Puccinia striiformis f. sp. tritici, also shows nonrace-specific, high-temperature adult-plant (HTAP) resistance to the stripe rust pathogen. To separate and identify the HTAP resistance gene, seeds of AvSYr17NIL were treated with ethyl methanesulfonate. Mutant lines with only HTAP resistance were obtained, and one of the lines, M1225, was crossed with the susceptible recurrent parent Avocet S (AvS). Field responses of the F2 plants and F3 lines, together with the parents, were recorded at the adult-plant stage in Pullman and Mount Vernon, WA under natural P. striiformis f. sp. tritici infection. The parents and the F4 population were phenotyped with a Yr17-virulent P. striiformis f. sp. tritici race in the adult-plant stage under the high-temperature profile in the greenhouse. The phenotypic results were confirmed by testing the F5 population in the field under natural P. striiformis f. sp. tritici infection. The F2 data indicated a single recessive gene, temporarily named YrM1225, for HTAP resistance. The F4 lines were genotyped with Kompetitive allele-specific PCR markers converted from single-nucleotide polymorphism markers polymorphic between M1225 and AvS. The HTAP resistance gene was mapped on the short arm of chromosome 2A in an interval of 7.5 centimorgans using both linkage and quantitative trait locus mapping approaches. The separation of the HTAP resistance gene from Yr17 should improve the understanding and utilization of the different types of resistance.
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Affiliation(s)
- Yuxiang Li
- College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, U.S.A
| | - Lu Liu
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, U.S.A
| | - Meinan Wang
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, U.S.A
| | - Travis Ruff
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, U.S.A
| | - Deven R See
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, U.S.A
- United States Department of Agriculture Agricultural Research Service, Wheat Health, Genetics, and Quality Research Unit, Pullman, WA 99164-6430, U.S.A
| | - Xiaoping Hu
- College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Xianming Chen
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, U.S.A
- United States Department of Agriculture Agricultural Research Service, Wheat Health, Genetics, and Quality Research Unit, Pullman, WA 99164-6430, U.S.A
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Cui Z, Wu W, Fan F, Wang F, Liu D, Di D, Wang H. Transcriptome analysis of Lr19-virulent mutants provides clues for the AvrLr19 of Puccinia triticina. Front Microbiol 2023; 14:1062548. [PMID: 37032911 PMCID: PMC10073493 DOI: 10.3389/fmicb.2023.1062548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 03/06/2023] [Indexed: 04/11/2023] Open
Abstract
Introduction Wheat leaf rust caused by Puccinia triticina (Pt) remains one of the most destructive diseases of common wheat worldwide. Understanding the pathogenicity mechanisms of Pt is important to control wheat leaf rust. Methods The urediniospores of Pt race PHNT (wheat leaf rust resistance gene Lr19-avirulent isolate) were mutagenized with ethyl methanesulfonate (EMS), and two Lr19-virulent mutants named M1 and M2 were isolated. RNA sequencing was performed on samples collected from wheat cultivars Chinese Spring and TcLr19 infected with wild-type (WT) PHNT, M1, and M2 isolates at 14 days post-inoculation (dpi), respectively. Screening AvrLr19 candidates by quantitative reverse transcription PCR (qPCR) and Agrobacterium-mediated transient assays in Nicotiana benthamiana. Results 560 genes with single nucleotide polymorphisms (SNPs) and insertions or deletions (Indels) from non-differentially expressed genes were identified. Among them, 10 secreted proteins were screened based on their fragments per kilobase of exon model per million mapped reads (FPKM) values in the database. qPCR results showed that the expression profiles of 7 secreted proteins including PTTG_27471, PTTG_12441, PTTG_28324, PTTG_26499, PTTG_06910, PTTG_26516, and PTTG_03570 among 10 secreted proteins in mutants were significantly different with that in wild-type isolate after infection wheat TcLr19 and might be related to the recognition between Lr19 and AvrLr19. In addition, a total of 216 differentially expressed genes (DEGs) were obtained from three different sample comparisons including M1-vs-WT, M2-vs-WT, and M1-vs-M2. Among 216 DEGs, 15 were predicted to be secreted proteins. One secreted protein named PTTG_04779 could inhibit programmed progress of cell death (PCD) induced by apoptosis-controlling genes B-cell lymphoma-2 associated X protein (BAX) on Nicotiana benthamiana, indicating that it might play a virulence function in plant. Taken together, total 8 secreted proteins, PTTG_04779, PTTG_27471, PTTG_12441, PTTG_28324, PTTG_26499, PTTG_06910, PTTG_26516, PTTG_03570 are identified as AvrLr19 candidates. Discussion Our results showed that a large number of genes participate in the interaction between Pt and TcLr19, which will provide valuable resources for the identification of AvrLr19 candidates and pathogenesis-related genes.
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Affiliation(s)
- Zhongchi Cui
- College of Plant Protection, Technological Innovation Center for Biological Control of Crop Diseases and Insect Pests of Hebei Province, Hebei Agricultural University, Baoding, Hebei, China
| | - Wenyue Wu
- College of Plant Protection, Technological Innovation Center for Biological Control of Crop Diseases and Insect Pests of Hebei Province, Hebei Agricultural University, Baoding, Hebei, China
| | - Fan Fan
- College of Plant Protection, Technological Innovation Center for Biological Control of Crop Diseases and Insect Pests of Hebei Province, Hebei Agricultural University, Baoding, Hebei, China
| | - Fei Wang
- College of Plant Protection, Technological Innovation Center for Biological Control of Crop Diseases and Insect Pests of Hebei Province, Hebei Agricultural University, Baoding, Hebei, China
| | - Daqun Liu
- College of Plant Protection, Technological Innovation Center for Biological Control of Crop Diseases and Insect Pests of Hebei Province, Hebei Agricultural University, Baoding, Hebei, China
| | - Dianping Di
- Plant Protection Institute, Hebei Academy of Agricultural and Forestry Sciences, Baoding, Hebei, China
- *Correspondence: Dianping Di,
| | - Haiyan Wang
- College of Plant Protection, Technological Innovation Center for Biological Control of Crop Diseases and Insect Pests of Hebei Province, Hebei Agricultural University, Baoding, Hebei, China
- Haiyan Wang,
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Bai Q, Wang M, Xia C, See DR, Chen X. Identification of Secreted Protein Gene-Based SNP Markers Associated with Virulence Phenotypes of Puccinia striiformis f. sp. tritici, the Wheat Stripe Rust Pathogen. Int J Mol Sci 2022; 23:ijms23084114. [PMID: 35456934 PMCID: PMC9033109 DOI: 10.3390/ijms23084114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 04/07/2022] [Accepted: 04/07/2022] [Indexed: 01/14/2023] Open
Abstract
Stripe rust caused by Puccinia striiformis f. sp. tritici (Pst) is a destructive disease that occurs throughout the major wheat-growing regions of the world. This pathogen is highly variable due to the capacity of virulent races to undergo rapid changes in order to circumvent resistance in wheat cultivars and genotypes and to adapt to different environments. Intensive efforts have been made to study the genetics of wheat resistance to this disease; however, no known avirulence genes have been molecularly identified in Pst so far. To identify molecular markers for avirulence genes, a Pst panel of 157 selected isolates representing 126 races with diverse virulence spectra was genotyped using 209 secreted protein gene-based single nucleotide polymorphism (SP-SNP) markers via association analysis. Nineteen SP-SNP markers were identified for significant associations with 12 avirulence genes: AvYr1, AvYr6, AvYr7, AvYr9, AvYr10, AvYr24, AvYr27, AvYr32, AvYr43, AvYr44, AvYrSP, and AvYr76. Some SP-SNPs were associated with two or more avirulence genes. These results further confirmed that association analysis in combination with SP-SNP markers is a powerful tool for identifying markers for avirulence genes. This study provides genomic resources for further studies on the cloning of avirulence genes, understanding the mechanisms of host–pathogen interactions, and developing functional markers for tagging specific virulence genes and race groups.
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Affiliation(s)
- Qing Bai
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, USA; (Q.B.); (M.W.); (C.X.); (D.R.S.)
| | - Meinan Wang
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, USA; (Q.B.); (M.W.); (C.X.); (D.R.S.)
| | - Chongjing Xia
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, USA; (Q.B.); (M.W.); (C.X.); (D.R.S.)
- Wheat Research Institute, School of Life Sciences and Engineering, Southwest University of Science and Technology, Mianyang 621010, China
| | - Deven R. See
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, USA; (Q.B.); (M.W.); (C.X.); (D.R.S.)
- U.S. Department of Agriculture, Agricultural Research Service, Wheat Health, Genetics, and Quality Research Unit, Pullman, WA 99164-6430, USA
| | - Xianming Chen
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, USA; (Q.B.); (M.W.); (C.X.); (D.R.S.)
- U.S. Department of Agriculture, Agricultural Research Service, Wheat Health, Genetics, and Quality Research Unit, Pullman, WA 99164-6430, USA
- Correspondence: ; Tel.: +1-509-335-8086
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Liu T, Bai Q, Wang M, Li Y, Wan A, See DR, Xia C, Chen X. Genotyping Puccinia striiformis f. sp. tritici Isolates with SSR and SP-SNP Markers Reveals Dynamics of the Wheat Stripe Rust Pathogen in the United States from 1968 to 2009 and Identifies Avirulence-Associated Markers. PHYTOPATHOLOGY 2021; 111:1828-1839. [PMID: 33720751 DOI: 10.1094/phyto-01-21-0010-r] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Stripe rust, caused by Puccinia striiformis f. sp. tritici, is a devastating disease of wheat (Triticum aestivum) in the United States. The fungal pathogen can rapidly evolve, producing new virulent races infecting previously resistant cultivars and genotypes adapting to different environments. The objective of this study was to investigate the long-term population dynamics of P. striiformis f. sp. tritici in the United States. Through genotyping 1,083 isolates taken from 1968 to 2009, using 14 simple sequence repeat (SSR) markers and 92 secreted protein single nucleotide polymorphism (SP-SNP) markers, 614 and 945 genotypes were detected, respectively. In general, the two types of markers produced consistent genetic relationships among the P. striiformis f. sp. tritici populations over the 40-year period. The prior-to-2000 and the 2000-to-2009 populations were significantly different, with the latter showing higher genotypic diversity and higher heterozygosity than the earlier populations. Clustering analyses using genotypes of either SSR or SP-SNP markers revealed three molecular groups (MGs), MG1, MG2, and MG3. The prior-to-2000 and the 2000-to-2009 groups both had evidence of MG1 and MG2; however, MG3 was only found in the 2000-to-2009 population. Some of the isolates in the period of 2000 to 2009 formed individual clusters, suggesting exotic incursions. Other isolates of the same period were clustered with prior-to-2000 isolates, indicating that they were developed from the previously established populations. The data suggest the coexistence of newly introduced populations alongside established populations in the United States. Twenty SP-SNP markers were significantly associated to individual avirulence genes. These results are useful for developing more accurate monitoring systems and provide guidance for disease management.
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Affiliation(s)
- Tinglan Liu
- Department of Plant Pathology, Washington State University, Pullman 99164-6430, U.S.A
- College of Life Science and Biotechnology, Mianyang Normal University, Mianyang, Sichuan 621010, China
| | - Qing Bai
- Department of Plant Pathology, Washington State University, Pullman 99164-6430, U.S.A
| | - Meinan Wang
- Department of Plant Pathology, Washington State University, Pullman 99164-6430, U.S.A
| | - Yuxiang Li
- Department of Plant Pathology, Washington State University, Pullman 99164-6430, U.S.A
| | - Anmin Wan
- Department of Plant Pathology, Washington State University, Pullman 99164-6430, U.S.A
| | - Deven R See
- Department of Plant Pathology, Washington State University, Pullman 99164-6430, U.S.A
- Wheat Health, Genetics, and Quality Research Unit, U.S. Department of Agriculture, Agricultural Research Service, Pullman 99164-6430, U.S.A
| | - Chongjing Xia
- Department of Plant Pathology, Washington State University, Pullman 99164-6430, U.S.A
- Wheat Research Institute, School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan 621010, China
| | - Xianming Chen
- Department of Plant Pathology, Washington State University, Pullman 99164-6430, U.S.A
- Wheat Health, Genetics, and Quality Research Unit, U.S. Department of Agriculture, Agricultural Research Service, Pullman 99164-6430, U.S.A
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Bai Q, Wan A, Wang M, See DR, Chen X. Molecular Characterization of Wheat Stripe Rust Pathogen ( Puccinia striiformis f. sp. tritici) Collections from Nine Countries. Int J Mol Sci 2021; 22:ijms22179457. [PMID: 34502363 PMCID: PMC8430876 DOI: 10.3390/ijms22179457] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 08/23/2021] [Accepted: 08/27/2021] [Indexed: 11/20/2022] Open
Abstract
Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most important diseases of wheat worldwide. To understand the worldwide distribution of its molecular groups, as well as the diversity, differentiation, and migration of the Pst populations, 567 isolates collected from nine countries (China, Pakistan, Italy, Egypt, Ethiopia, Canada, Mexico, Ecuador, and the U.S.) in 2010–2018 were genotyped using 14 codominant simple sequence repeat markers. A total of 433, including 333 new multi-locus genotypes (MLGs), were identified, which were clustered into ten molecular groups (MGs). The MGs and country-wise populations differed in genetic diversity, heterozygosity, and correlation coefficient between the marker and virulence data. Many isolates from different countries, especially the isolates from Mexico, Ecuador, and the U.S., were found to be identical or closely related MLGs, and some of the MGs were present in all countries, indicating Pst migrations among different countries. The analysis of molecular variance revealed 78% variation among isolates, 12% variation among countries, and 10% variation within countries. Only low levels of differentiation were found by the pairwise comparisons of country populations. Of the 10 MGs, 5 were found to be involved in sexual and/or somatic recombination. Identical and closely related MLGs identified from different countries indicated international migrations. The study provides information on the distributions of various Pst genetic groups in different countries and evidence for the global migrations, which should be useful in understanding the pathogen evolution and in stressing the need for continual monitoring of the disease and pathogen populations at the global scale.
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Affiliation(s)
- Qing Bai
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, USA; (Q.B.); (A.W.); (M.W.); (D.R.S.)
| | - Anmin Wan
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, USA; (Q.B.); (A.W.); (M.W.); (D.R.S.)
| | - Meinan Wang
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, USA; (Q.B.); (A.W.); (M.W.); (D.R.S.)
| | - Deven R. See
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, USA; (Q.B.); (A.W.); (M.W.); (D.R.S.)
- U.S. Department of Agriculture, Agricultural Research Service, Wheat Health, Genetics, and Quality Research Unit, Pullman, WA 99164-6430, USA
| | - Xianming Chen
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, USA; (Q.B.); (A.W.); (M.W.); (D.R.S.)
- U.S. Department of Agriculture, Agricultural Research Service, Wheat Health, Genetics, and Quality Research Unit, Pullman, WA 99164-6430, USA
- Correspondence: ; Tel.: +1-509-335-8086
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Bai Q, Wan A, Wang M, See DR, Chen X. Population Diversity, Dynamics, and Differentiation of Wheat Stripe Rust Pathogen Puccinia striiformis f. sp. tritici From 2010 to 2017 and Comparison With 1968 to 2009 in the United States. Front Microbiol 2021; 12:696835. [PMID: 34367096 PMCID: PMC8339480 DOI: 10.3389/fmicb.2021.696835] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 06/14/2021] [Indexed: 01/25/2023] Open
Abstract
Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a serious disease on wheat in the United States, especially after 2000. In the present study, 2,247 Pst isolates collected over all stripe rust epidemiological regions in the United States from 2010 to 2017 were genotyped at 14 simple sequence repeat (SSR) loci to investigate the population diversity, dynamics, and differentiation. A total of 1,454 multilocus genotypes (MLGs) were detected. In general, the populations in the west (regions 1-6) had more MLGs and higher diversities than the populations in the east (regions 7-12). The populations of 2010 and 2011 were more different from the other years. Genetic variation was higher among years than among regions, indicating the fast changes of the population. The divergence (Gst) was bigger between the west population and east population than among regions within either the west or east population. Gene flow was stronger among the regional populations in the east than in the west. Clustering analyses revealed 3 major molecular groups (MGs) and 10 sub-MGs by combining the genotypic data of 2010-2017 isolates with those of 1968-2009. MG1 contained both 1968-2009 isolates (23.1%) and 2010-2017 isolates (76.9%). MG2 had 99.4% of isolates from 1968-2009. MG3, which was the most recent and distinct group, had 99.1% of isolates from 2010-2017. Of the 10 sub-MGs, 5 (MG1-3, MG1-5, MG3-2, MG3-3, and MG3-4) were detected only from 2011 to 2017. The SSR genotypes had a moderate, but significant correlation (r = 0.325; p < 0.0001) with the virulence phenotype data. The standard index values of association (rbarD = 0.11) based on either regional or yearly populations suggest clonal reproduction. This study indicated high diversity, fast dynamics, and various levels of differentiation of the Pst population over the years and among epidemiological regions, and the results should be useful for managing wheat stripe rust.
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Affiliation(s)
- Qing Bai
- Department of Plant Pathology, Washington State University, Pullman, WA, United States
| | - Anmin Wan
- Department of Plant Pathology, Washington State University, Pullman, WA, United States
| | - Meinan Wang
- Department of Plant Pathology, Washington State University, Pullman, WA, United States
| | - Deven R. See
- Department of Plant Pathology, Washington State University, Pullman, WA, United States
- Wheat Health, Genetics, and Quality Research Unit, United States Department of Agriculture, Agricultural Research Service, Pullman, WA, United States
| | - Xianming Chen
- Department of Plant Pathology, Washington State University, Pullman, WA, United States
- Wheat Health, Genetics, and Quality Research Unit, United States Department of Agriculture, Agricultural Research Service, Pullman, WA, United States
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Sinha P, Chen X. Potential Infection Risks of the Wheat Stripe Rust and Stem Rust Pathogens on Barberry in Asia and Southeastern Europe. PLANTS 2021; 10:plants10050957. [PMID: 34064962 PMCID: PMC8151100 DOI: 10.3390/plants10050957] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/07/2021] [Accepted: 05/07/2021] [Indexed: 11/16/2022]
Abstract
Barberry (Berberis spp.) is an alternate host for both the stripe rust pathogen, Puccinia striiformis f. sp. tritici (Pst), and the stem rust pathogen, P. graminis f. sp. tritici (Pgt), infecting wheat. Infection risk was assessed to determine whether barberry could be infected by either of the pathogens in Asia and Southeastern Europe, known for recurring epidemics on wheat and the presence of barberry habitats. For assessing infection risk, mechanistic infection models were used to calculate infection indices for both pathogens on barberry following a modeling framework. In East Asia, Bhutan, China, and Nepal were found to have low risks of barberry infection by Pst but high risks by Pgt. In Central Asia, Azerbaijan, Iran, Kazakhstan, southern Russia, and Uzbekistan were identified to have low to high risks of barberry infection for both Pst and Pgt. In Northwest Asia, risk levels of both pathogens in Turkey and the Republic of Georgia were determined to be high to very high. In Southwest Asia, no or low risk was found. In Southeastern Europe, similar high or very high risks for both pathogens were noted for all countries. The potential risks of barberry infection by Pst and/or Pgt should provide guidelines for monitoring barberry infections and could be valuable for developing rust management programs in these regions. The framework used in this study may be useful to predict rust infection risk in other regions.
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Affiliation(s)
- Parimal Sinha
- ICAR-Indian Agricultural Research Institute, New Delhi 110012, India;
- 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
- US Department of Agriculture—Agricultural Research Service, Wheat Health, Genetics, and Quality Research Unit, Pullman, WA 99164-6430, USA
- Correspondence: ; Tel.: +1-509-335-8086
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Barsoum M, Kusch S, Frantzeskakis L, Schaffrath U, Panstruga R. Ultraviolet Mutagenesis Coupled with Next-Generation Sequencing as a Method for Functional Interrogation of Powdery Mildew Genomes. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2020; 33:1008-1021. [PMID: 32370643 DOI: 10.1094/mpmi-02-20-0035-ta] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Powdery mildews are obligate biotrophic fungal pathogens causing important diseases of plants worldwide. Very little is known about the requirements for their pathogenicity at the molecular level. This is largely due to the inability to culture these organisms in vitro or to modify them genetically. Here, we describe a mutagenesis procedure based on ultraviolet (UV) irradiation to accumulate mutations in the haploid genome of the barley powdery mildew pathogen Blumeria graminis f. sp. hordei. Exposure of B. graminis f. sp. hordei conidia to different durations of UV-C radiation (10 s to 12 min) resulted in a reduced number of macroscopically visible fungal colonies. B. graminis f. sp. hordei colony number was negatively correlated with exposure time and the total number of consecutive cycles of UV irradiation. Dark incubation following UV exposure further reduced fungal viability, implying that photoreactivation is an important component of DNA repair in B. graminis f. sp. hordei. After several rounds of UV mutagenesis, we selected two mutant isolates in addition to the parental B. graminis f. sp. hordei K1 isolate for whole-genome resequencing. By combining automated prediction of sequence variants and their manual validation, we identified unique UV-induced mutations in the genomes of the two isolates. Most of these mutations were in the up- or downstream regions of genes or in the intergenic space. Some of the variants detected in genes led to predicted missense mutations. As an additional insight, our bioinformatic analyses revealed a complex population structure within supposedly clonal B. graminis f. sp. hordei isolates.
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Affiliation(s)
- Mirna Barsoum
- RWTH Aachen University, Institute for Biology I, Unit of Plant Molecular Cell Biology, Worringerweg 1, 52056 Aachen, Germany
| | - Stefan Kusch
- RWTH Aachen University, Institute for Biology I, Unit of Plant Molecular Cell Biology, Worringerweg 1, 52056 Aachen, Germany
| | - Lamprinos Frantzeskakis
- RWTH Aachen University, Institute for Biology I, Unit of Plant Molecular Cell Biology, Worringerweg 1, 52056 Aachen, Germany
| | - Ulrich Schaffrath
- RWTH Aachen University, Institute for Biology III, Worringerweg 1, 52056 Aachen, Germany
| | - Ralph Panstruga
- RWTH Aachen University, Institute for Biology I, Unit of Plant Molecular Cell Biology, Worringerweg 1, 52056 Aachen, Germany
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Li Y, Xia C, Wang M, Yin C, Chen X. Whole-genome sequencing of Puccinia striiformis f. sp. tritici mutant isolates identifies avirulence gene candidates. BMC Genomics 2020; 21:247. [PMID: 32197579 PMCID: PMC7085141 DOI: 10.1186/s12864-020-6677-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 03/13/2020] [Indexed: 12/30/2022] Open
Abstract
Background The stripe rust pathogen, Puccinia striiformis f. sp. tritici (Pst), threats world wheat production. Resistance to Pst is often overcome by pathogen virulence changes, but the mechanisms of variation are not clearly understood. To determine the role of mutation in Pst virulence changes, in previous studies 30 mutant isolates were developed from a least virulent isolate using ethyl methanesulfonate (EMS) mutagenesis and phenotyped for virulence changes. The progenitor isolate was sequenced, assembled and annotated for establishing a high-quality reference genome. In the present study, the 30 mutant isolates were sequenced and compared to the wide-type isolate to determine the genomic variation and identify candidates for avirulence (Avr) genes. Results The sequence reads of the 30 mutant isolates were mapped to the wild-type reference genome to identify genomic changes. After selecting EMS preferred mutations, 264,630 and 118,913 single nucleotide polymorphism (SNP) sites and 89,078 and 72,513 Indels (Insertion/deletion) were detected among the 30 mutant isolates compared to the primary scaffolds and haplotigs of the wild-type isolate, respectively. Deleterious variants including SNPs and Indels occurred in 1866 genes. Genome wide association analysis identified 754 genes associated with avirulence phenotypes. A total of 62 genes were found significantly associated to 16 avirulence genes after selection through six criteria for putative effectors and degree of association, including 48 genes encoding secreted proteins (SPs) and 14 non-SP genes but with high levels of association (P ≤ 0.001) to avirulence phenotypes. Eight of the SP genes were identified as avirulence-associated effectors with high-confidence as they met five or six criteria used to determine effectors. Conclusions Genome sequence comparison of the mutant isolates with the progenitor isolate unraveled a large number of mutation sites along the genome and identified high-confidence effector genes as candidates for avirulence genes in Pst. Since the avirulence gene candidates were identified from associated SNPs and Indels caused by artificial mutagenesis, these avirulence gene candidates are valuable resources for elucidating the mechanisms of the pathogen pathogenicity, and will be studied to determine their functions in the interactions between the wheat host and the Pst pathogen.
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Affiliation(s)
- Yuxiang Li
- Department of Plant Pathology, Washington State University, Pullman, WA, 99164-6430, USA
| | - 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
| | - Xianming Chen
- Department of Plant Pathology, Washington State University, Pullman, WA, 99164-6430, USA. .,USDA-ARS, Wheat Health, Genetics, and Quality Research Unit, Pullman, WA, 99164-6430, USA.
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