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Holden S, Bergum M, Green P, Bettgenhaeuser J, Hernández-Pinzón I, Thind A, Clare S, Russell JM, Hubbard A, Taylor J, Smoker M, Gardiner M, Civolani L, Cosenza F, Rosignoli S, Strugala R, Molnár I, Šimková H, Doležel J, Schaffrath U, Barrett M, Salvi S, Moscou MJ. A lineage-specific Exo70 is required for receptor kinase-mediated immunity in barley. SCIENCE ADVANCES 2022; 8:eabn7258. [PMID: 35857460 PMCID: PMC9258809 DOI: 10.1126/sciadv.abn7258] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
In the evolution of land plants, the plant immune system has experienced expansion in immune receptor and signaling pathways. Lineage-specific expansions have been observed in diverse gene families that are potentially involved in immunity but lack causal association. Here, we show that Rps8-mediated resistance in barley to the pathogen Puccinia striiformis f. sp. tritici (wheat stripe rust) is conferred by a genetic module: Pur1 and Exo70FX12, which are together necessary and sufficient. Pur1 encodes a leucine-rich repeat receptor kinase and is the ortholog of rice Xa21, and Exo70FX12 belongs to the Poales-specific Exo70FX clade. The Exo70FX clade emerged after the divergence of the Bromeliaceae and Poaceae and comprises from 2 to 75 members in sequenced grasses. These results demonstrate the requirement of a lineage-specific Exo70FX12 in Pur1-mediated immunity and suggest that the Exo70FX clade may have evolved a specialized role in receptor kinase signaling.
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Affiliation(s)
- Samuel Holden
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Molly Bergum
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Phon Green
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Jan Bettgenhaeuser
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | | | - Anupriya Thind
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Shaun Clare
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - James M. Russell
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Amelia Hubbard
- NIAB, 93 Lawrence Weaver Road, Cambridge CB3 0LE, England, UK
| | - Jodi Taylor
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Matthew Smoker
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Matthew Gardiner
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Laura Civolani
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
- Department of Agricultural and Food Sciences, University of Bologna, Viale G. Fanin 44, 40127 Bologna, Italy
| | - Francesco Cosenza
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
- Department of Agricultural and Food Sciences, University of Bologna, Viale G. Fanin 44, 40127 Bologna, Italy
| | - Serena Rosignoli
- Department of Agricultural and Food Sciences, University of Bologna, Viale G. Fanin 44, 40127 Bologna, Italy
| | - Roxana Strugala
- Department of Plant Physiology, RWTH Aachen University, 52056 Aachen, Germany
| | - István Molnár
- Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany of the Czech Academy of Sciences, Šlechtitelů 31, 779 00 Olomouc, Czech Republic
| | - Hana Šimková
- Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany of the Czech Academy of Sciences, Šlechtitelů 31, 779 00 Olomouc, Czech Republic
| | - Jaroslav Doležel
- Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany of the Czech Academy of Sciences, Šlechtitelů 31, 779 00 Olomouc, Czech Republic
| | - Ulrich Schaffrath
- Department of Plant Physiology, RWTH Aachen University, 52056 Aachen, Germany
| | - Matthew Barrett
- Australian Tropical Herbarium, James Cook University, Smithfield 4878, Australia
| | - Silvio Salvi
- Department of Agricultural and Food Sciences, University of Bologna, Viale G. Fanin 44, 40127 Bologna, Italy
| | - Matthew J. Moscou
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
- Corresponding author.
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Bettgenhaeuser J, Hernández-Pinzón I, Dawson AM, Gardiner M, Green P, Taylor J, Smoker M, Ferguson JN, Emmrich P, Hubbard A, Bayles R, Waugh R, Steffenson BJ, Wulff BBH, Dreiseitl A, Ward ER, Moscou MJ. The barley immune receptor Mla recognizes multiple pathogens and contributes to host range dynamics. Nat Commun 2021; 12:6915. [PMID: 34824299 PMCID: PMC8617247 DOI: 10.1038/s41467-021-27288-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 11/11/2021] [Indexed: 11/25/2022] Open
Abstract
Crop losses caused by plant pathogens are a primary threat to stable food production. Stripe rust (Puccinia striiformis) is a fungal pathogen of cereal crops that causes significant, persistent yield loss. Stripe rust exhibits host species specificity, with lineages that have adapted to infect wheat and barley. While wheat stripe rust and barley stripe rust are commonly restricted to their corresponding hosts, the genes underlying this host specificity remain unknown. Here, we show that three resistance genes, Rps6, Rps7, and Rps8, contribute to immunity in barley to wheat stripe rust. Rps7 cosegregates with barley powdery mildew resistance at the Mla locus. Using transgenic complementation of different Mla alleles, we confirm allele-specific recognition of wheat stripe rust by Mla. Our results show that major resistance genes contribute to the host species specificity of wheat stripe rust on barley and that a shared genetic architecture underlies resistance to the adapted pathogen barley powdery mildew and non-adapted pathogen wheat stripe rust.
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Affiliation(s)
- Jan Bettgenhaeuser
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, NR4 7UK, England, UK
- KWS SAAT SE & Co. KGaA, 37574, Einbeck, Germany
| | | | - Andrew M Dawson
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, NR4 7UK, England, UK
| | - Matthew Gardiner
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, NR4 7UK, England, UK
| | - Phon Green
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, NR4 7UK, England, UK
| | - Jodie Taylor
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, NR4 7UK, England, UK
| | - Matthew Smoker
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, NR4 7UK, England, UK
| | - John N Ferguson
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, NR4 7UK, England, UK
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
| | - Peter Emmrich
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, NR4 7UK, England, UK
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Amelia Hubbard
- NIAB, 93 Lawrence Weaver Road, Cambridge, CB3 0LE, England, UK
| | - Rosemary Bayles
- NIAB, 93 Lawrence Weaver Road, Cambridge, CB3 0LE, England, UK
| | - Robbie Waugh
- The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, Scotland, UK
| | - Brian J Steffenson
- Department of Plant Pathology, University of Minnesota, St. Paul, MN, 55108, USA
| | - Brande B H Wulff
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, NR4 7UK, England, UK
- Center for Desert Agriculture, Biological and Environmental Science and Engineering Division (BESE), King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Antonín Dreiseitl
- Department of Integrated Plant Protection, Agrotest Fyto Ltd, Havlíčkova 2787, CZ-767 01, Kroměříž, Czech Republic
| | - Eric R Ward
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, NR4 7UK, England, UK
- AgBiome, Research Triangle Park, NC, 27709, USA
| | - Matthew J Moscou
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, NR4 7UK, England, UK.
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Panstruga R, Moscou MJ. What is the Molecular Basis of Nonhost Resistance? MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2020; 33:1253-1264. [PMID: 32808862 DOI: 10.1094/mpmi-06-20-0161-cr] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
This article is part of the Top 10 Unanswered Questions in MPMI invited review series.Nonhost resistance is typically considered the ability of a plant species to repel all attempts of a pathogen species to colonize it and reproduce on it. Based on this common definition, nonhost resistance is presumed to be very durable and, thus, of great interest for its potential use in agriculture. Despite considerable research efforts, the molecular basis of this type of plant immunity remains nebulous. We here stress the fact that "nonhost resistance" is a phenomenological rather than a mechanistic concept that comprises more facets than typically considered. We further argue that nonhost resistance essentially relies on the very same genes and pathways as other types of plant immunity, of which some may act as bottlenecks for particular pathogens on a given plant species or under certain conditions. Thus, in our view, the frequently used term "nonhost genes" is misleading and should be avoided. Depending on the plant-pathogen combination, nonhost resistance may involve the recognition of pathogen effectors by host immune sensor proteins, which might give rise to host shifts or host range expansions due to evolutionary-conditioned gains and losses in respective armories. Thus, the extent of nonhost resistance also defines pathogen host ranges. In some instances, immune-related genes can be transferred across plant species to boost defense, resulting in augmented disease resistance. We discuss future routes for deepening our understanding of nonhost resistance and argue that the confusing term "nonhost resistance" should be used more cautiously in the light of a holistic view of plant immunity.
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Affiliation(s)
- Ralph Panstruga
- RWTH Aachen University, Institute for Biology I, Unit of Plant Molecular Cell Biology, Worringer Weg 1, 52056 Aachen, Germany
| | - Matthew J Moscou
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, NR4 7UK, United Kingdom
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Gao S, Xia J, Yuan S, Shen Y, Zhong X, Zhang S, Li Y, Hu D, Zeng J, Lan T, Liu Y, Chen G. Novel QTL Conferring Phosphorus Acquisition and Utilization Efficiencies in Barley. Front Genet 2020; 11:580452. [PMID: 33101396 PMCID: PMC7500284 DOI: 10.3389/fgene.2020.580452] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 08/12/2020] [Indexed: 11/13/2022] Open
Abstract
Phosphorus (P) deficiency in agricultural soil is a major constraint for crop production and increasing P acquisition efficiency (PAE) of plants is considered as one of the most cost-effective solutions for yield increase. The objective of this study was to detect quantitative trait loci (QTL) controlling (PAE) and P utilization efficiency (PUE) in barley under applied (+P) and non-applied P (-P) conditions. Based on the analysis of a recombinant inbred lines (RILs) population derived from a cross between a malting barley variety and a wild barley accession, 17 QTL controlling PAE, PUE and yield traits were detected. The phenotypic variation explained by each of these QTL ranges from 11.0 to 24.7%. Significant correlation was detected between most of P-related traits and yield traits. Five QTL clusters were identified on four different chromosomes (1H, 3H, 5H, and 7H). Two of the QTL clusters, located on chromosome 1H (for GPUP/PUP) and 7H (for SPUE/SPC), respectively, are novel. Fourteen genes located in the interval harboring the major QTL were identified as candidates associated with P efficiency. The stable QTL for PAE, PUE and yield-related traits could be important for breeding P-efficient barley varieties.
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Affiliation(s)
- Shangqing Gao
- College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Jiaqi Xia
- College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Shu Yuan
- College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Youjie Shen
- College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Xinting Zhong
- College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Senfeng Zhang
- College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Yuhang Li
- College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Deyi Hu
- College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Jian Zeng
- College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Ting Lan
- College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Yaxi Liu
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, China
| | - Guangdeng Chen
- College of Resources, Sichuan Agricultural University, Chengdu, China
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Ma X, Xu Z, Wang J, Chen H, Ye X, Lin Z. Pairing and Exchanging between Daypyrum villosum Chromosomes 6V#2 and 6V#4 in the Hybrids of Two Different Wheat Alien Substitution Lines. Int J Mol Sci 2019; 20:ijms20236063. [PMID: 31805728 PMCID: PMC6929145 DOI: 10.3390/ijms20236063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 11/21/2019] [Accepted: 11/27/2019] [Indexed: 11/16/2022] Open
Abstract
Normal pairing and exchanging is an important basis to evaluate the genetic relationship between homologous chromosomes in a wheat background. The pairing behavior between 6V#2 and 6V#4, two chromosomes from different Dasypyrum villosum accessions, is still not clear. In this study, two wheat alien substitution lines, 6V#2 (6A) and 6V#4 (6D), were crossed to obtain the F1 hybrids and F2 segregating populations, and the testcross populations were obtained by using the F1 as a parent crossed with wheat variety Wan7107. The chromosomal behavior at meiosis in pollen mother cells (PMCs) of the F1 hybrids was observed using a genomic in situ hybridization (GISH) technique. Exchange events of two alien chromosomes were investigated in the F2 populations using nine polymerase chain reaction (PCR) markers located on the 6V short arm. The results showed that the two alien chromosomes could pair with each other to form ring- or rod-shaped bivalent chromosomes in 79.76% of the total PMCs, and most were pulled to two poles evenly at anaphase I. Investigation of the F2 populations showed that the segregation ratios of seven markers were consistent with the theoretical values 3:1 or 1:2:1, and recombinants among markers were detected. A genetic linkage map of nine PCR markers for 6VS was accordingly constructed based on the exchange frequencies and compared with the physical maps of wheat and barley based on homologous sequences of the markers, which showed that conservation of sequence order compared to 6V was 6H and 6B > 6A > 6D. In the testcross populations with 482 plants, seven showed susceptibility to powdery mildew (PM) and lacked amplification of alien chromosomal bands. Six other plants had amplification of specific bands of both the alien chromosomes at multiple sites, which suggested that the alien chromosomes had abnormal separation behavior in about 1.5% of the PMCs in F1, which resulted in some gametes containing two alien chromosomes. In addition, three new types of chromosome substitution were developed. This study lays a foundation for alien allelism tests and further assessment of the genetic relationship among 6V#2, 6V#4, and their wheat homoeologous chromosomes.
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Affiliation(s)
- Xiaolan Ma
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (X.M.); (Z.X.); (J.W.); (H.C.); (X.Y.)
| | - Zhiying Xu
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (X.M.); (Z.X.); (J.W.); (H.C.); (X.Y.)
- Agricultural College, Guangdong Ocean University, Zhanjiang 524088, China
| | - Jing Wang
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (X.M.); (Z.X.); (J.W.); (H.C.); (X.Y.)
| | - Haiqiang Chen
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (X.M.); (Z.X.); (J.W.); (H.C.); (X.Y.)
| | - Xingguo Ye
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (X.M.); (Z.X.); (J.W.); (H.C.); (X.Y.)
- National Key Facility of Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Zhishan Lin
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (X.M.); (Z.X.); (J.W.); (H.C.); (X.Y.)
- National Key Facility of Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, China
- Correspondence:
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Bartaula R, Melo ATO, Kingan S, Jin Y, Hale I. Mapping non-host resistance to the stem rust pathogen in an interspecific barberry hybrid. BMC PLANT BIOLOGY 2019; 19:319. [PMID: 31311507 PMCID: PMC6636152 DOI: 10.1186/s12870-019-1893-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 06/19/2019] [Indexed: 05/17/2023]
Abstract
BACKGROUND Non-host resistance (NHR) presents a compelling long-term plant protection strategy for global food security, yet the genetic basis of NHR remains poorly understood. For many diseases, including stem rust of wheat [causal organism Puccinia graminis (Pg)], NHR is largely unexplored due to the inherent challenge of developing a genetically tractable system within which the resistance segregates. The present study turns to the pathogen's alternate host, barberry (Berberis spp.), to overcome this challenge. RESULTS In this study, an interspecific mapping population derived from a cross between Pg-resistant Berberis thunbergii (Bt) and Pg-susceptible B. vulgaris was developed to investigate the Pg-NHR exhibited by Bt. To facilitate QTL analysis and subsequent trait dissection, the first genetic linkage maps for the two parental species were constructed and a chromosome-scale reference genome for Bt was assembled (PacBio + Hi-C). QTL analysis resulted in the identification of a single 13 cM region (~ 5.1 Mbp spanning 13 physical contigs) on the short arm of Bt chromosome 3. Differential gene expression analysis, combined with sequence variation analysis between the two parental species, led to the prioritization of several candidate genes within the QTL region, some of which belong to gene families previously implicated in disease resistance. CONCLUSIONS Foundational genetic and genomic resources developed for Berberis spp. enabled the identification and annotation of a QTL associated with Pg-NHR. Although subsequent validation and fine mapping studies are needed, this study demonstrates the feasibility of and lays the groundwork for dissecting Pg-NHR in the alternate host of one of agriculture's most devastating pathogens.
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Affiliation(s)
- Radhika Bartaula
- Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, NH 03824 USA
| | - Arthur T. O. Melo
- Department of Agriculture, Nutrition, and Food Systems, University of New Hampshire, Durham, NH 03824 USA
| | | | - Yue Jin
- USDA-ARS Cereal Disease Laboratory, St. Paul, MN 55108 USA
| | - Iago Hale
- Department of Agriculture, Nutrition, and Food Systems, University of New Hampshire, Durham, NH 03824 USA
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Transgressive segregation reveals mechanisms of Arabidopsis immunity to Brassica-infecting races of white rust ( Albugo candida). Proc Natl Acad Sci U S A 2019; 116:2767-2773. [PMID: 30692254 PMCID: PMC6377460 DOI: 10.1073/pnas.1812911116] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Most plants resist most plant pathogens. Barley resists wheat-infecting powdery mildew races (and vice versa), and both barley and wheat resist potato late blight. Such “nonhost” resistance could result because the pathogen fails to suppress defense or triggers innate immunity due to failure to evade detection. Albugo candida causes white rust on most Brassicaceae, and we investigated Arabidopsis NHR to Brassica-infecting races. Transgressive segregation for resistance in Arabidopsis recombinant inbred lines revealed genes encoding nucleotide-binding, leucine-rich repeat (NLR) immune receptors. Some of these NLR-encoding genes confer resistance to white rust in Brassica sp. This genetic method thus provides a route to reveal resistance genes for crops, widening the pool from which such genes might be obtained. Arabidopsis thaliana accessions are universally resistant at the adult leaf stage to white rust (Albugo candida) races that infect the crop species Brassica juncea and Brassica oleracea. We used transgressive segregation in recombinant inbred lines to test if this apparent species-wide (nonhost) resistance in A. thaliana is due to natural pyramiding of multiple Resistance (R) genes. We screened 593 inbred lines from an Arabidopsis multiparent advanced generation intercross (MAGIC) mapping population, derived from 19 resistant parental accessions, and identified two transgressive segregants that are susceptible to the pathogen. These were crossed to each MAGIC parent, and analysis of resulting F2 progeny followed by positional cloning showed that resistance to an isolate of A. candida race 2 (Ac2V) can be explained in each accession by at least one of four genes encoding nucleotide-binding, leucine-rich repeat (NLR) immune receptors. An additional gene was identified that confers resistance to an isolate of A. candida race 9 (AcBoT) that infects B. oleracea. Thus, effector-triggered immunity conferred by distinct NLR-encoding genes in multiple A. thaliana accessions provides species-wide resistance to these crop pathogens.
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Zhang R, Fan Y, Kong L, Wang Z, Wu J, Xing L, Cao A, Feng Y. Pm62, an adult-plant powdery mildew resistance gene introgressed from Dasypyrum villosum chromosome arm 2VL into wheat. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2018; 131:2613-2620. [PMID: 30167758 DOI: 10.1007/s00122-018-3176-5] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 08/25/2018] [Indexed: 05/19/2023]
Abstract
Pm62, a novel adult-plant resistance (APR) gene against powdery mildew, was transferred from D. villosum into common wheat in the form of Robertsonian translocation T2BS.2VL#5. Powdery mildew, which is caused by the fungus Blumeria graminis f. sp. tritici, is a major disease of wheat resulting in substantial yield and quality losses in many wheat production regions of the world. Introgression of resistance from wild species into common wheat has application for controlling this disease. A Triticum durum-Dasypyrum villosum chromosome 2V#5 disomic addition line, N59B-1 (2n = 30), improved resistance to powdery mildew at the adult-plant stage, which was attributable to chromosome 2V#5. To transfer this resistance into bread wheat, a total of 298 BC1F1 plants derived from the crossing between N59B-1 and Chinese Spring were screened by combined genomic in situ hybridization and fluorescent in situ hybridization, 2V-specific marker analysis, and reaction to powdery mildew to confirm that a dominant adult-plant resistance gene, designated as Pm62, was located on chromosome 2VL#5. Subsequently, the 2VL#5 (2D) disomic substitution line (NAU1825) and the homozygous T2BS.2VL#5 Robertsonian translocation line (NAU1823), with normal plant vigor and full fertility, were identified by molecular and cytogenetic analyses of the BC1F2 generation. The effects of the T2BS.2VL#5 recombinant chromosome on agronomic traits were also evaluated in the F2 segregation population. The results suggest that the translocated chromosome may have no distinct effect on plant height, 1000-kernel weight or flowering period, but a slight effect on spike length and seeds per spike. The translocation line NAU1823 has being utilized as a novel germplasm in breeding for powdery mildew resistance, and the effects of the T2BS.2VL#5 recombinant chromosome on yield-related and flour quality characters will be further assessed.
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Affiliation(s)
- Ruiqi Zhang
- College of Agronomy/JCIC-MCP/National Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
| | - Yali Fan
- College of Agronomy/JCIC-MCP/National Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Lingna Kong
- College of Agronomy/JCIC-MCP/National Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Zuojun Wang
- College of Agronomy/JCIC-MCP/National Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Jizhong Wu
- Institute of Germplasm Resources and Biotechnology/Provincial Key Laboratory of Agrobiology, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, People's Republic of China
| | - Liping Xing
- College of Agronomy/JCIC-MCP/National Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Aizhong Cao
- College of Agronomy/JCIC-MCP/National Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Yigao Feng
- College of Agronomy/JCIC-MCP/National Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
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Türkösi E, Darko E, Rakszegi M, Molnár I, Molnár-Láng M, Cseh A. Development of a new 7BS.7HL winter wheat-winter barley Robertsonian translocation line conferring increased salt tolerance and (1,3;1,4)-β-D-glucan content. PLoS One 2018; 13:e0206248. [PMID: 30395616 PMCID: PMC6218033 DOI: 10.1371/journal.pone.0206248] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 10/09/2018] [Indexed: 01/01/2023] Open
Abstract
Interspecific hybridization between bread wheat (Triticum aestivum, 2n = 42) and related species allows the transfer of agronomic and quality traits, whereby subsequent generations comprise an improved genetic background and can be directly applied in wheat breeding programmes. While wild relatives are frequently used as sources of agronomically favourable traits, cultivated species can also improve wheat quality and stress resistance. A salt-tolerant 'Asakaze'/'Manas' 7H disomic addition line (2n = 44) with elevated β-glucan content, but with low fertility and an unstable genetic background was developed in an earlier wheat-barley prebreeding programme. The aim of the present study was to take this hybridization programme further and transfer the favourable barley traits into a more stable genetic background. Taking advantage of the breakage-fusion mechanism of univalent chromosomes, the 'Rannaya' winter wheat 7B monosomic line was used as female partner to the 7H addition line male, leading to the development of a compensating wheat/barley Robertsonian translocation line (7BS.7HL centric fusion, 2n = 42) exhibiting higher salt tolerance and elevated grain β-glucan content. Throughout the crossing programme, comprising the F1-F4 generations, genomic in situ hybridization, fluorescence in situ hybridization and chromosome-specific molecular markers were used to trace and identify the wheat and barley chromatin. Investigations on salt tolerance during germination and on the (1,3;1,4)-β-D-glucan (mixed-linkage glucan [MLG]) content of the seeds confirmed the salt tolerance and elevated grain MLG content of the translocation line, which can be directly applied in current wheat breeding programmes.
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Affiliation(s)
- Edina Türkösi
- Department of Plant Genetic Resources, Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Martonvásár, Hungary
| | - Eva Darko
- Department of Plant Physiology, Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Martonvásár, Hungary
| | - Marianna Rakszegi
- Cereal Breeding Department, Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Martonvásár, Hungary
| | - István Molnár
- Maize Breeding Department, Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Martonvásár, Hungary
| | - Márta Molnár-Láng
- Department of Plant Genetic Resources, Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Martonvásár, Hungary
| | - András Cseh
- Molecular Breeding Department, Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Martonvásár, Hungary
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10
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Gilbert B, Bettgenhaeuser J, Upadhyaya N, Soliveres M, Singh D, Park RF, Moscou MJ, Ayliffe M. Components of Brachypodium distachyon resistance to nonadapted wheat stripe rust pathogens are simply inherited. PLoS Genet 2018; 14:e1007636. [PMID: 30265668 PMCID: PMC6161853 DOI: 10.1371/journal.pgen.1007636] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 08/15/2018] [Indexed: 11/19/2022] Open
Abstract
Phytopathogens have a limited range of host plant species that they can successfully parasitise ie. that they are adapted for. Infection of plants by nonadapted pathogens often results in an active resistance response that is relatively poorly characterised because phenotypic variation in this response often does not exist within a plant species, or is too subtle for genetic dissection. In addition, complex polygenic inheritance often underlies these resistance phenotypes and mutagenesis often does not impact upon this resistance, presumably due to genetic or mechanistic redundancy. Here it is demonstrated that phenotypic differences in the resistance response of Brachypodium distachyon to the nonadapted wheat stripe rust pathogen Puccinia striiformis f. sp. tritici (Pst) are genetically tractable and simply inherited. Two dominant loci were identified on B. distachyon chromosome 4 that each reduce attempted Pst colonisation compared with sib and parent lines without these loci. One locus (Yrr1) is effective against diverse Australian Pst isolates and present in two B. distachyon mapping families as a conserved region that was reduced to 5 candidate genes by fine mapping. A second locus, Yrr2, shows Pst race-specificity and encodes a disease resistance gene family typically associated with host plant resistance. These data indicate that some components of resistance to nonadapted pathogens are genetically tractable in some instances and may mechanistically overlap with host plant resistance to avirulent adapted pathogens.
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Affiliation(s)
- Brian Gilbert
- CSIRO Agriculture and Food, Clunies Ross Drive, Canberra, ACT, Australia
| | - Jan Bettgenhaeuser
- The Sainsbury Laboratory, Norwich Research Park, Norwich, United Kingdom
| | - Narayana Upadhyaya
- CSIRO Agriculture and Food, Clunies Ross Drive, Canberra, ACT, Australia
| | - Melanie Soliveres
- CSIRO Agriculture and Food, Clunies Ross Drive, Canberra, ACT, Australia
| | - Davinder Singh
- University of Sydney, Plant Breeding Institute, Cobbitty, NSW, Australia
| | - Robert F. Park
- University of Sydney, Plant Breeding Institute, Cobbitty, NSW, Australia
| | - Matthew J. Moscou
- The Sainsbury Laboratory, Norwich Research Park, Norwich, United Kingdom
- University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Michael Ayliffe
- CSIRO Agriculture and Food, Clunies Ross Drive, Canberra, ACT, Australia
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11
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Haghdoust R, Singh D, Garnica DP, Park RF, Dracatos PM. Isolate Specificity and Polygenic Inheritance of Resistance in Barley to Diverse Heterologous Puccinia striiformis Isolates. PHYTOPATHOLOGY 2018; 108:617-626. [PMID: 29271300 DOI: 10.1094/phyto-10-17-0345-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Barley is a host to Puccinia striiformis f. sp. hordei, and is an intermediate or near nonhost to the formae speciales adapted to wheat (P. striiformis f. sp. tritici) and to barley grass (P. striiformis f. sp. pseudo-hordei). The genetic basis of resistance to these forms of P. striiformis is not well understood. Accordingly, a recombinant inbred line (RIL) population was developed using a P. striiformis-susceptible accession (Biosaline-19) and the immune cultivar Pompadour. We investigated the genetic basis of resistance to four diverse P. striiformis isolates (P. striiformis f. sp. pseudo-hordei, and P. striiformis f. sp. tritici pathotypes 104 E137 A-, 134 E16 A+, and 64 E0 A-). and determined that the immunity in Pompadour at the seedling stage to the different P. striiformis isolates was due to quantitative trait loci (QTL) on chromosomes 1H, 3H, 5H, and 7H with both overlapping and distinct specificities. Further histological analysis confirmed the presence of isolate specificity. The RILs were also assessed in the field for resistance to P. striiformis f. sp. pseudo-hordei, P. striiformis f. sp. hordei, and the leaf rust pathogen (P. hordei) to identify pleiotropic QTL loci effective at the adult plant stage and determine whether the leaf rust resistance in Pompadour (Rph20) was also effective to P. striiformis. RILs that were seedling susceptible to P. striiformis f. sp. pseudo-hordei were resistant in the field, implicating the involvement of adult plant resistance (APR). Additional QTLs were identified on chromosome 7H at the same genetic position as Rph23 (APR to leaf rust), suggesting either pleiotropic resistance or the presence of a stripe rust resistance gene closely linked to or allelic with Rph23. Unlike many pleiotropic APR genes identified and isolated in wheat, our data suggest that the Rph20 locus does not confer resistance to the P. striiformis isolates used in this study (P. striiformis f. sp. hordei [χ2 (independence) = 2.47 P > 0.12] and P. striiformis f. sp. pseudo-hordei [χ2 (independence) = 0.42 P > 0.60]).
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Affiliation(s)
- R Haghdoust
- First, second, fourth, and fifth authors: The University of Sydney, Plant Breeding Institute, Cobbitty, Private Bag 4011, Narellan, NSW, 2567, Australia; and second author: CSIRO Plant Industries, GPO Box 1600, Canberra, ACT, 2601, Australia
| | - D Singh
- First, second, fourth, and fifth authors: The University of Sydney, Plant Breeding Institute, Cobbitty, Private Bag 4011, Narellan, NSW, 2567, Australia; and second author: CSIRO Plant Industries, GPO Box 1600, Canberra, ACT, 2601, Australia
| | - D P Garnica
- First, second, fourth, and fifth authors: The University of Sydney, Plant Breeding Institute, Cobbitty, Private Bag 4011, Narellan, NSW, 2567, Australia; and second author: CSIRO Plant Industries, GPO Box 1600, Canberra, ACT, 2601, Australia
| | - R F Park
- First, second, fourth, and fifth authors: The University of Sydney, Plant Breeding Institute, Cobbitty, Private Bag 4011, Narellan, NSW, 2567, Australia; and second author: CSIRO Plant Industries, GPO Box 1600, Canberra, ACT, 2601, Australia
| | - P M Dracatos
- First, second, fourth, and fifth authors: The University of Sydney, Plant Breeding Institute, Cobbitty, Private Bag 4011, Narellan, NSW, 2567, Australia; and second author: CSIRO Plant Industries, GPO Box 1600, Canberra, ACT, 2601, Australia
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12
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Bartaula R, Melo ATO, Connolly BA, Jin Y, Hale I. An interspecific barberry hybrid enables genetic dissection of non-host resistance to the stem rust pathogen Puccinia graminis. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:2483-2493. [PMID: 29529250 PMCID: PMC5920301 DOI: 10.1093/jxb/ery066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 02/15/2018] [Indexed: 05/28/2023]
Abstract
Stem rust, caused by Puccinia graminis (Pg), remains a devastating disease of wheat, and the emergence of new Pg races virulent on deployed resistance genes fuels the ongoing search for sources of durable resistance. Despite its intrinsic durability, non-host resistance (NHR) is largely unexplored as a protection strategy against Pg, partly due to the inherent challenge of developing a genetically tractable system within which NHR segregates. Here, we demonstrate that Pg's far less studied ancestral host, barberry (Berberis spp.), provides such a unique pathosystem. Characterization of a natural population of B. ×ottawensis, an interspecific hybrid of Pg-susceptible B. vulgaris and Pg-resistant B. thunbergii (Bt), reveals that this uncommon nothospecies can be used to dissect the genetic mechanism(s) of Pg-NHR exhibited by Bt. Artificial inoculation of a natural population of B. ×ottawensis accessions, verified via genotyping by sequencing to be first-generation hybrids, revealed 51% susceptible, 33% resistant, and 16% intermediate phenotypes. Characterization of a B. ×ottawensis full sib family excluded the possibility of maternal inheritance of the resistance. By demonstrating segregation of Pg-NHR in a hybrid population, this study challenges the assumed irrelevance of Bt to Pg epidemiology and lays a novel foundation for the genetic dissection of NHR to one of agriculture's most studied pathogens.
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Affiliation(s)
- Radhika Bartaula
- Department of Agriculture, Nutrition, and Food Systems, University of New Hampshire, Durham, NH, USA
| | - Arthur T O Melo
- Department of Agriculture, Nutrition, and Food Systems, University of New Hampshire, Durham, NH, USA
| | - Bryan A Connolly
- Department of Biology, Framingham State University, Framingham, MA, USA
| | - Yue Jin
- USDA-ARS Cereal Disease Laboratory, St. Paul, MN, USA
| | - Iago Hale
- Department of Agriculture, Nutrition, and Food Systems, University of New Hampshire, Durham, NH, USA
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13
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Danilova TV, Friebe B, Gill BS, Poland J, Jackson E. Development of a complete set of wheat-barley group-7 Robertsonian translocation chromosomes conferring an increased content of β-glucan. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2018; 131:377-388. [PMID: 29124282 DOI: 10.1007/s00122-017-3008-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 10/26/2017] [Indexed: 05/06/2023]
Abstract
A complete set of six compensating Robertsonian translocation chromosomes involving barley chromosome 7H and three chromosomes of hexaploid wheat was produced. Grain β-glucan content increased in lines containing 7HL. Many valuable genes for agronomic performance, disease resistance and increased yield have been transferred from relative species to wheat (Triticum aestivum L.) through whole-arm Robertsonian translocations (RobT). Although of a great value, the sets of available translocations from barley (Hordeum vulgare L.) are limited. Here, we present the production of a complete set of six compensating RobT chromosomes involving barley chromosome 7H and three group-7 chromosomes of wheat. The barley group-7 long-arm RobTs had a higher grain β-glucan content compared to the wheat control. The β-glucan levels varied depending on the temperature and were higher under hot conditions. Implicated in this increase, the barley cellulose synthase-like F6 gene (CslF6) responsible for β-glucan synthesis was physically mapped near the centromere in the long arm of barley chromosome 7H. Likewise, wheat CslF6 homoeologs were mapped near the centromere in the long arms of all group-7 wheat chromosomes. With the set of novel wheat-barley translocations, we demonstrate a valuable increase of β-glucan, along with a resource of genetic stocks that are likely to carry many other important genes from barley into wheat.
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Affiliation(s)
- Tatiana V Danilova
- Department of Plant Pathology, Wheat Genetics Resource Center, Throckmorton Plant Sciences Center, Kansas State University, Manhattan, KS, 66506-5502, USA
| | - Bernd Friebe
- Department of Plant Pathology, Wheat Genetics Resource Center, Throckmorton Plant Sciences Center, Kansas State University, Manhattan, KS, 66506-5502, USA.
| | - Bikram S Gill
- Department of Plant Pathology, Wheat Genetics Resource Center, Throckmorton Plant Sciences Center, Kansas State University, Manhattan, KS, 66506-5502, USA
| | - Jesse Poland
- Department of Plant Pathology, Wheat Genetics Resource Center, Throckmorton Plant Sciences Center, Kansas State University, Manhattan, KS, 66506-5502, USA
| | - Eric Jackson
- General Mills NTS [AI]2 Lab, Minneapolis, MN, 55426, USA
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14
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Zhao J, Yang Y, Yang D, Cheng Y, Jiao M, Zhan G, Zhang H, Wang J, Zhou K, Huang L, Kang Z. Characterization and Genetic Analysis of Rice Mutant crr1 Exhibiting Compromised Non-host Resistance to Puccinia striiformis f. sp. tritici ( Pst). FRONTIERS IN PLANT SCIENCE 2016; 7:1822. [PMID: 27965705 PMCID: PMC5127839 DOI: 10.3389/fpls.2016.01822] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Accepted: 11/18/2016] [Indexed: 05/12/2023]
Abstract
Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most devastating diseases of wheat in China. Rapid change to virulence following release of resistant cultivars necessitates ongoing discovery and exploitation of new resistance resources. Considerable effort has been directed at non-host resistance (NHR) which is believed to be durable. In the present study we identified rice mutant crr1 (compromised resistance to rust 1) that exhibited compromised NHR to Pst. Compared with wild type rice variety Nipponbare, crr1 mutant displayed a threefold increase in penetration rate by Pst, and enhanced hyphal growth. The pathogen also developed haustoria in crr1 mesophyll cells, but failed to sporulate. The response to the adapted rice pathogen Magnaporthe oryzae was unchanged in crr1 relative to the wild type. Several defense-related genes involved in the SA- and JA-mediated defense pathways response and in phytoalexin synthesis (such as OsPR1a, OsLOX1, and OsCPS4) were more rapidly and strongly induced in infected crr1 leaves than in the wild type, suggesting that other layers of defense are still in effect. Genetic analysis and mapping located the mutant loci at a region between markers ID14 and RM25792, which cover about 290 kb genome sequence on chromosome 10. Further fine mapping and cloning of the locus should provide further insights into NHR to rust fungi in rice, and may reveal new strategies for improving rust resistance in wheat.
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Affiliation(s)
- Jing Zhao
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F UniversityYangling, China
| | - Yuheng Yang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F UniversityYangling, China
| | - Donghe Yang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F UniversityYangling, China
| | - Yulin Cheng
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F UniversityYangling, China
| | - Min Jiao
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F UniversityYangling, China
| | - Gangming Zhan
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F UniversityYangling, China
| | - Hongchang Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Science, Northwest A&F UniversityYangling, China
| | - Junyi Wang
- Shaanxi Rice Research Institute, Hanzhong Agricultural Science InstituteHanzhong, China
| | - Kai Zhou
- Shaanxi Rice Research Institute, Hanzhong Agricultural Science InstituteHanzhong, China
| | - Lili Huang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F UniversityYangling, China
| | - Zhensheng Kang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F UniversityYangling, China
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15
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Dawson AM, Ferguson JN, Gardiner M, Green P, Hubbard A, Moscou MJ. Isolation and fine mapping of Rps6: an intermediate host resistance gene in barley to wheat stripe rust. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2016; 129:831-843. [PMID: 26754419 PMCID: PMC4799244 DOI: 10.1007/s00122-015-2659-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 12/14/2015] [Indexed: 05/24/2023]
Abstract
We uncouple host and nonhost resistance in barley to Puccinia striiformis ff. spp. hordei and tritici . We isolate, fine map, and physically anchor Rps6 to chromosome 7H in barley. A plant may be considered a nonhost of a pathogen if all known genotypes of a plant species are resistant to all known isolates of a pathogen species. However, if a small number of genotypes are susceptible to some known isolates of a pathogen species this plant may be considered an intermediate host. Barley (Hordeum vulgare) is an intermediate host for Puccinia striiformis f. sp. tritici (Pst), the causal agent of wheat stripe rust. We wanted to understand the genetic architecture underlying resistance to Pst and to determine whether any overlap exists with resistance to the host pathogen, Puccinia striiformis f. sp. hordei (Psh). We mapped Pst resistance to chromosome 7H and show that host and intermediate host resistance is genetically uncoupled. Therefore, we designate this resistance locus Rps6. We used phenotypic and genotypic selection on F2:3 families to isolate Rps6 and fine mapped the locus to a 0.1 cM region. Anchoring of the Rps6 locus to the barley physical map placed the region on a single fingerprinted contig spanning a physical region of 267 kb. Efforts are now underway to sequence the minimal tiling path and to delimit the physical region harboring Rps6. This will facilitate additional marker development and permit identification of candidate genes in the region.
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Affiliation(s)
- Andrew M Dawson
- The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK
| | - John N Ferguson
- The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK
- School of Biological Sciences, University of Essex, Colchester, CO4 3SQ, UK
| | - Matthew Gardiner
- The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Phon Green
- The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Amelia Hubbard
- National Institute of Agricultural Botany, Huntingdon Road, Cambridge, CB3 0LE, UK
| | - Matthew J Moscou
- The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK.
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