1
|
Lhamo D, Sun Q, Friesen TL, Karmacharya A, Li X, Fiedler JD, Faris JD, Xia G, Luo M, Gu YQ, Liu Z, Xu SS. Association mapping of tan spot and septoria nodorum blotch resistance in cultivated emmer wheat. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2024; 137:193. [PMID: 39073628 DOI: 10.1007/s00122-024-04700-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Accepted: 07/21/2024] [Indexed: 07/30/2024]
Abstract
KEY MESSAGE A total of 65 SNPs associated with resistance to tan spot and septoria nodorum blotch were identified in a panel of 180 cultivated emmer accessions through association mapping Tan spot and septoria nodorum blotch (SNB) are foliar diseases caused by the respective fungal pathogens Pyrenophora tritici-repentis and Parastagonospora nodorum that affect global wheat production. To find new sources of resistance, we evaluated a panel of 180 cultivated emmer wheat (Triticum turgidum ssp. dicoccum) accessions for reactions to four P. tritici-repentis isolates Pti2, 86-124, 331-9 and DW5, two P. nodorum isolate, Sn4 and Sn2000, and four necrotrophic effectors (NEs) produced by the pathogens. About 8-36% of the accessions exhibited resistance to the four P. tritici-repentis isolates, with five accessions demonstrating resistance to all isolates. For SNB, 64% accessions showed resistance to Sn4, 43% to Sn2000 and 36% to both isolates, with Spain (11% accessions) as the most common origin of resistance. To understand the genetic basis of resistance, association mapping was performed using SNP (single nucleotide polymorphism) markers generated by genotype-by-sequencing and the 9 K SNP Infinium array. A total of 46 SNPs were significantly associated with tan spot and 19 SNPs with SNB resistance or susceptibility. Six trait loci on chromosome arms 1BL, 3BL, 4AL (2), 6BL and 7AL conferred resistance to two or more isolates. Known NE sensitivity genes for disease development were undetected except Snn5 for Sn2000, suggesting novel genetic factors are controlling host-pathogen interaction in cultivated emmer. The emmer accessions with the highest levels of resistance to the six pathogen isolates (e.g., CItr 14133-1, PI 94634-1 and PI 377672) could serve as donors for tan spot and SNB resistance in wheat breeding programs.
Collapse
Affiliation(s)
- Dhondup Lhamo
- USDA-ARS, Crop Improvement and Genetics Research Unit, Western Regional Research Center, Albany, CA, 94710, USA
| | - Qun Sun
- Department of Plant Sciences, North Dakota State University, Fargo, ND, 58108, USA
| | - Timothy L Friesen
- USDA-ARS, Cereal Crops Research Unit, Edward T. Schafer Agricultural Research Center, Fargo, ND, 58102, USA
| | - Anil Karmacharya
- Department of Plant Sciences, University of California, Davis, CA, 95616, USA
| | - Xuehui Li
- Department of Plant Sciences, North Dakota State University, Fargo, ND, 58108, USA
| | - Jason D Fiedler
- USDA-ARS, Cereal Crops Research Unit, Edward T. Schafer Agricultural Research Center, Fargo, ND, 58102, USA
| | - Justin D Faris
- USDA-ARS, Cereal Crops Research Unit, Edward T. Schafer Agricultural Research Center, Fargo, ND, 58102, USA
| | - Guangmin Xia
- Key Laboratory of Plant Development and Environmental Adaptation Biology, School of Life Science, Shandong University, Qingdao, 266237, China
| | - Mingcheng Luo
- Department of Plant Sciences, University of California, Davis, CA, 95616, USA
| | - Yong-Qiang Gu
- USDA-ARS, Crop Improvement and Genetics Research Unit, Western Regional Research Center, Albany, CA, 94710, USA
| | - Zhaohui Liu
- Department of Plant Pathology, North Dakota State University, Fargo, ND, 58108, USA.
| | - Steven S Xu
- USDA-ARS, Crop Improvement and Genetics Research Unit, Western Regional Research Center, Albany, CA, 94710, USA.
| |
Collapse
|
2
|
Mandal R, He X, Singh G, Kabir MR, Joshi AK, Singh PK. Screening of CIMMYT and South Asian Bread Wheat Germplasm Reveals Marker-Trait Associations for Seedling Resistance to Septoria Nodorum Blotch. Genes (Basel) 2024; 15:890. [PMID: 39062669 PMCID: PMC11276481 DOI: 10.3390/genes15070890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2024] [Revised: 07/02/2024] [Accepted: 07/05/2024] [Indexed: 07/28/2024] Open
Abstract
Wheat (Triticum aestivum L.) production is adversely impacted by Septoria nodorum blotch (SNB), a fungal disease caused by Parastagonospora nodorum. Wheat breeders are constantly up against this biotic challenge as they try to create resistant cultivars. The genome-wide association study (GWAS) has become an efficient tool for identifying molecular markers linked with SNB resistance. This technique is used to acquire an understanding of the genetic basis of resistance and to facilitate marker-assisted selection. In the current study, a total of 174 bread wheat accessions from South Asia and CIMMYT were assessed for SNB reactions at the seedling stage in three greenhouse experiments at CIMMYT, Mexico. The results indicated that 129 genotypes were resistant to SNB, 39 were moderately resistant, and only 6 were moderately susceptible. The Genotyping Illumina Infinium 15K Bead Chip was used, and 11,184 SNP markers were utilized to identify marker-trait associations (MTAs) after filtering. Multiple tests confirmed the existence of significant MTAs on chromosomes 5B, 5A, and 3D, and the ones at Tsn1 on 5B were the most stable and conferred the highest phenotypic variation. The resistant genotypes identified in this study could be cultivated in South Asian countries as a preventative measure against the spread of SNB. This work also identified molecular markers of SNB resistance that could be used in future wheat breeding projects.
Collapse
Affiliation(s)
- Rupsanatan Mandal
- Visiting Scientist, International Maize and Wheat Improvement Center (CIMMYT), Texcoco 56237, Mexico;
- Department of Genetics and Plant Breeding, Uttar Banga Krishi Viswavidyalaya, Cooch Behar 736165, India
| | - Xinyao He
- International Maize and Wheat Improvement Centre, Texcoco 56237, Mexico;
| | - Gyanendra Singh
- ICAR-Indian Institute of Wheat and Barley Research, Karnal 132001, India;
| | | | - Arun Kumar Joshi
- International Maize and Wheat Improvement Center (CIMMYT)-India Office, New Delhi 110012, India;
- Borlaug Institute for South Asia, New Delhi 110012, India
| | - Pawan Kumar Singh
- International Maize and Wheat Improvement Centre, Texcoco 56237, Mexico;
| |
Collapse
|
3
|
Peters Haugrud AR, Shi G, Seneviratne S, Running KLD, Zhang Z, Singh G, Szabo-Hever A, Acharya K, Friesen TL, Liu Z, Faris JD. Genome-wide association mapping of resistance to the foliar diseases septoria nodorum blotch and tan spot in a global winter wheat collection. MOLECULAR BREEDING : NEW STRATEGIES IN PLANT IMPROVEMENT 2023; 43:54. [PMID: 37337566 PMCID: PMC10276793 DOI: 10.1007/s11032-023-01400-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 06/02/2023] [Indexed: 06/21/2023]
Abstract
Septoria nodorum blotch (SNB) and tan spot, caused by the necrotrophic fungal pathogens Parastagonospora nodorum and Pyrenophora tritici-repentis, respectively, often occur together as a leaf spotting disease complex on wheat (Triticum aestivum L.). Both pathogens produce necrotrophic effectors (NEs) that contribute to the development of disease. Here, genome-wide association analysis of a diverse panel of 264 winter wheat lines revealed novel loci on chromosomes 5A and 5B associated with sensitivity to the NEs SnTox3 and SnTox5 in addition to the known sensitivity genes for NEs Ptr/SnToxA, SnTox1, SnTox3, and SnTox5. Sensitivity loci for SnTox267 and Ptr ToxB were not detected. Evaluation of the panel with five P. nodorum isolates for SNB development indicated the Snn3-SnTox3 and Tsn1-SnToxA interactions played significant roles in disease development along with additional QTL on chromosomes 2A and 2D, which may correspond to the Snn7-SnTox267 interaction. For tan spot, the Tsc1-Ptr ToxC interaction was associated with disease caused by two isolates, and a novel QTL on chromosome 7D was associated with a third isolate. The Tsn1-ToxA interaction was associated with SNB but not tan spot. Therefore some, but not all, of the previously characterized host gene-NE interactions in these pathosystems play significant roles in disease development in winter wheat. Based on these results, breeders should prioritize the selection of resistance alleles at the Tsc1, Tsn1, Snn3, and Snn7 loci as well as the 2A and 7D QTL to obtain good levels of resistance to SNB and tan spot in winter wheat. Supplementary Information The online version contains supplementary material available at 10.1007/s11032-023-01400-5.
Collapse
Affiliation(s)
- Amanda R. Peters Haugrud
- Cereal Crops Research Unit, Edward T. Schafer Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, , Fargo, ND 58102 USA
| | - Gongjun Shi
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58102 USA
| | - Sudeshi Seneviratne
- Department of Plant Sciences, North Dakota State University, Fargo, ND 58102 USA
| | | | - Zengcui Zhang
- Cereal Crops Research Unit, Edward T. Schafer Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, , Fargo, ND 58102 USA
| | - Gurminder Singh
- Department of Plant Sciences, North Dakota State University, Fargo, ND 58102 USA
| | - Agnes Szabo-Hever
- Cereal Crops Research Unit, Edward T. Schafer Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, , Fargo, ND 58102 USA
| | - Krishna Acharya
- Department of Plant Sciences, North Dakota State University, Fargo, ND 58102 USA
| | - Timothy L. Friesen
- Cereal Crops Research Unit, Edward T. Schafer Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, , Fargo, ND 58102 USA
| | - Zhaohui Liu
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58102 USA
| | - Justin D. Faris
- Cereal Crops Research Unit, Edward T. Schafer Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, , Fargo, ND 58102 USA
| |
Collapse
|
4
|
Gupta PK, Vasistha NK, Singh S, Joshi AK. Genetics and breeding for resistance against four leaf spot diseases in wheat ( Triticum aestivum L.). FRONTIERS IN PLANT SCIENCE 2023; 14:1023824. [PMID: 37063191 PMCID: PMC10096043 DOI: 10.3389/fpls.2023.1023824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Accepted: 02/28/2023] [Indexed: 06/19/2023]
Abstract
In wheat, major yield losses are caused by a variety of diseases including rusts, spike diseases, leaf spot and root diseases. The genetics of resistance against all these diseases have been studied in great detail and utilized for breeding resistant cultivars. The resistance against leaf spot diseases caused by each individual necrotroph/hemi-biotroph involves a complex system involving resistance (R) genes, sensitivity (S) genes, small secreted protein (SSP) genes and quantitative resistance loci (QRLs). This review deals with resistance for the following four-leaf spot diseases: (i) Septoria nodorum blotch (SNB) caused by Parastagonospora nodorum; (ii) Tan spot (TS) caused by Pyrenophora tritici-repentis; (iii) Spot blotch (SB) caused by Bipolaris sorokiniana and (iv) Septoria tritici blotch (STB) caused by Zymoseptoria tritici.
Collapse
Affiliation(s)
- Pushpendra Kumar Gupta
- Department of Genetics and Plant Breeding, Chaudhary Charan Singh University, Meerut, India
- Murdoch’s Centre for Crop and Food Innovation, Murdoch University, Murdoch, WA, Australia
- Borlaug Institute for South Asia (BISA), National Agricultural Science Complex (NASC), Dev Prakash Shastri (DPS) Marg, New Delhi, India
| | - Neeraj Kumar Vasistha
- Department of Genetics and Plant Breeding, Chaudhary Charan Singh University, Meerut, India
- Department of Genetics-Plant Breeding and Biotechnology, Dr Khem Singh Gill, Akal College of Agriculture, Eternal University, Baru Sahib, Sirmour, India
| | - Sahadev Singh
- Department of Genetics and Plant Breeding, Chaudhary Charan Singh University, Meerut, India
| | - Arun Kumar Joshi
- Borlaug Institute for South Asia (BISA), National Agricultural Science Complex (NASC), Dev Prakash Shastri (DPS) Marg, New Delhi, India
- The International Maize and Wheat Improvement Center (CIMMYT), National Agricultural Science Complex (NASC), Dev Prakash Shastri (DPS) Marg, New Delhi, India
| |
Collapse
|
5
|
Zanella CM, Rotondo M, McCormick‐Barnes C, Mellers G, Corsi B, Berry S, Ciccone G, Day R, Faralli M, Galle A, Gardner KA, Jacobs J, Ober ES, Sánchez del Rio A, Van Rie J, Lawson T, Cockram J. Longer epidermal cells underlie a quantitative source of variation in wheat flag leaf size. THE NEW PHYTOLOGIST 2023; 237:1558-1573. [PMID: 36519272 PMCID: PMC10107444 DOI: 10.1111/nph.18676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 11/17/2022] [Indexed: 06/17/2023]
Abstract
The wheat flag leaf is the main contributor of photosynthetic assimilates to developing grains. Understanding how canopy architecture strategies affect source strength and yield will aid improved crop design. We used an eight-founder population to investigate the genetic architecture of flag leaf area, length, width and angle in European wheat. For the strongest genetic locus identified, we subsequently created a near-isogenic line (NIL) pair for more detailed investigation across seven test environments. Genetic control of traits investigated was highly polygenic, with colocalisation of replicated quantitative trait loci (QTL) for one or more traits identifying 24 loci. For QTL QFll.niab-5A.1 (FLL5A), development of a NIL pair found the FLL5A+ allele commonly conferred a c. 7% increase in flag and second leaf length and a more erect leaf angle, resulting in higher flag and/or second leaf area. Increased FLL5A-mediated flag leaf length was associated with: (1) longer pavement cells and (2) larger stomata at lower density, with a trend for decreased maximum stomatal conductance (Gsmax ) per unit leaf area. For FLL5A, cell size rather than number predominantly determined leaf length. The observed trade-offs between leaf size and stomatal morphology highlight the need for future studies to consider these traits at the whole-leaf level.
Collapse
Affiliation(s)
| | - Marilena Rotondo
- NIAB93 Lawrence Weaver RoadCambridgeCB3 0LEUK
- University of MessinaMessina98122Italy
| | | | | | | | | | - Giulia Ciccone
- NIAB93 Lawrence Weaver RoadCambridgeCB3 0LEUK
- University of MessinaMessina98122Italy
| | - Rob Day
- NIAB93 Lawrence Weaver RoadCambridgeCB3 0LEUK
| | - Michele Faralli
- School of Biological SciencesUniversity of EssexColchesterCO4 3SQUK
| | - Alexander Galle
- BASF Belgium Coordination Center (BBCC) – Innovation Center GhentTechnologiepark‐Zwijnaarde 1019052GhentBelgium
| | | | - John Jacobs
- BASF Belgium Coordination Center (BBCC) – Innovation Center GhentTechnologiepark‐Zwijnaarde 1019052GhentBelgium
| | | | | | - Jeroen Van Rie
- BASF Belgium Coordination Center (BBCC) – Innovation Center GhentTechnologiepark‐Zwijnaarde 1019052GhentBelgium
| | - Tracy Lawson
- School of Biological SciencesUniversity of EssexColchesterCO4 3SQUK
| | | |
Collapse
|
6
|
Lau KJX, Gusareva ES, Luhung I, Premkrishnan BNV, Wong A, Poh TY, Uchida A, Oliveira EL, Drautz-Moses DI, Junqueira ACM, Schuster SC. Structure vs. chemistry: Alternate mechanisms for controlling leaf microbiomes. PLoS One 2023; 18:e0275734. [PMID: 36943839 PMCID: PMC10030040 DOI: 10.1371/journal.pone.0275734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Accepted: 09/22/2022] [Indexed: 03/23/2023] Open
Abstract
The analysis of phyllosphere microbiomes traditionally relied on DNA extracted from whole leaves. To investigate the microbial communities on the adaxial (upper) and abaxial (lower) leaf surfaces, swabs were collected from both surfaces of two garden plants, Rhapis excelsa and Cordyline fruticosa. Samples were collected at noon and midnight and at five different locations to investigate if the phyllosphere microbial communities change with time and location. The abaxial surface of Rhapis excelsa and Cordyline fruticosa had fewer bacteria in contrast to its adaxial counterpart. This observation was consistent between noon and midnight and across five different locations. Our co-occurrence network analysis further showed that bacteria were found almost exclusively on the adaxial surface while only a small group of leaf blotch fungi thrived on the abaxial surface. There are higher densities of stomata on the abaxial surface and these openings are vulnerable ports of entry into the plant host. While one might argue about the settling of dust particles and microorganisms on the adaxial surface, we detected differences in reactive chemical activities and microstructures between the adaxial and abaxial surfaces. Our results further suggest that both plant species deploy different defence strategies to deter invading pathogens on the abaxial surface. We hypothesize that chemical and mechanical defence strategies evolved independently for harnessing and controlling phyllosphere microbiomes. Our findings have also advanced our understanding that the abaxial leaf surface is distinct from the adaxial surface and that the reduced microbial diversity is likely a consequence of plant-microbe interactions.
Collapse
Affiliation(s)
- Kenny J X Lau
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Elena S Gusareva
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- The Asian School of the Environment, Nanyang Technological University, Singapore, Singapore
| | - Irvan Luhung
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Balakrishnan N V Premkrishnan
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Anthony Wong
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Tuang Yeow Poh
- Translational Respiratory Research Laboratory, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Akira Uchida
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Elaine L Oliveira
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Daniela I Drautz-Moses
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Ana Carolina M Junqueira
- Departamento de Genética, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Stephan C Schuster
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| |
Collapse
|
7
|
Peters Haugrud AR, Zhang Z, Friesen TL, Faris JD. Genetics of resistance to septoria nodorum blotch in wheat. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2022; 135:3685-3707. [PMID: 35050394 DOI: 10.1007/s00122-022-04036-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 12/23/2021] [Indexed: 05/12/2023]
Abstract
Septoria nodorum blotch (SNB) is a foliar disease of wheat caused by the necrotrophic fungal pathogen Parastagonospora nodorum. Research over the last two decades has shown that the wheat-P. nodorum pathosystem mostly follows an inverse gene-for-gene model. The fungus produces necrotrophic effectors (NEs) that interact with specific host gene products encoded by dominant sensitivity (S) genes. When a compatible interaction occurs, a 'defense response' in the host leads to programmed cell death thereby provided dead/dying cells from which the pathogen, being a necrotroph, can acquire nutrients allowing it to grow and sporulate. To date, nine S gene-NE interactions have been characterized in this pathosystem. Five NE-encoding genes, SnTox1, SnTox3, SnToxA, SnTox5, and SnTox267, have been cloned along with three host S genes, Tsn1, Snn1, and Snn3-D1. Studies have shown that P. nodorum hijacks multiple and diverse host targets to cause disease. SNB resistance is often quantitative in nature because multiple compatible interactions usually occur concomitantly. NE gene expression plays a key role in disease severity, and the effect of each compatible interaction can vary depending on the other existing compatible interactions. Numerous SNB-resistance QTL have been identified in addition to the known S genes, and more research is needed to understand the nature of these resistance loci. Marker-assisted elimination of S genes through conventional breeding practices and disruption of S genes using gene editing techniques are both effective strategies for the development of SNB-resistant wheat cultivars, which will become necessary as the global demand for sustenance grows.
Collapse
Affiliation(s)
| | - Zengcui Zhang
- USDA-ARS Cereal Crops Research Unit, Edward T. Schafer Agricultural Research Center, Fargo, ND, 58102, USA
| | - Timothy L Friesen
- USDA-ARS Cereal Crops Research Unit, Edward T. Schafer Agricultural Research Center, Fargo, ND, 58102, USA
| | - Justin D Faris
- USDA-ARS Cereal Crops Research Unit, Edward T. Schafer Agricultural Research Center, Fargo, ND, 58102, USA.
| |
Collapse
|
8
|
Kartashov M, Voinova T, Shcherbakova L, Arslanova L, Chudakova K, Dzhavakhiya V. A Secondary Metabolite Secreted by Penicillium citrinum Is Able to Enhance Parastagonospora nodorum Sensitivity to Tebuconazole and Azoxystrobin. FRONTIERS IN FUNGAL BIOLOGY 2022; 3:889547. [PMID: 37746182 PMCID: PMC10512332 DOI: 10.3389/ffunb.2022.889547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 06/07/2022] [Indexed: 09/26/2023]
Abstract
Parastagonospora nodorum causes glume and leaf blotch of wheat, a harmful disease resulting in serious losses in grain yield. In many countries including Russia, fungicidal formulations based on triazoles and on triazoles combined with strobilurins are used to control this fungus. However, their prolonged application may promote the selection of fungicide-resistant strains of P. nodorum leading to significant attenuation or even loss of fungicidal effect. Chemosensitization of plant pathogenic fungi with natural compounds represents a promising strategy for mitigating fungicide resistance and other negative impacts of fungicides. In this work, we applied a chemosensitization approach towards P. nodorum strains non-resistant or resistant to tebuconazole or azoxystrobin using 6-demethylmevinolin (6-DMM), a metabolite of Penicillium citrinum. The resistant strains were obtained by the mutagenesis and subsequent culturing on agar media incorporated with increasing doses of Folicur® EC 250 (i.e., tebuconazole) or Quadris® SC 250 (i.e., azoxystrobin). Test strains m8-4 and kd-18, most resistant to tebuconazole and azoxystrobin, respectively, were selected for sensitization experiments. These experiments demonstrated that combining 6-DMM with Folicur® enhanced fungicidal effectiveness in vitro and in vivo in addition to attenuating the resistance of P. nodorum to tebuconazole in vitro. 6-DMM was also found to augment Quadris® efficacy towards kd-18 when applied on detached wheat leaves inoculated with this strain. Experiments on P. nodorum sensitization under greenhouse conditions included preventive (applying test compounds simultaneously with inoculation) or post-inoculation spraying of wheat seedlings with 6-DMM together with Folicur® at dose rates (DR) amounting to 10% and 20% of DR recommended for field application (RDR). Combined treatments were run in parallel with using the same DR of the fungicide and sensitizer, alone. A synergistic effect was observed in both preventive and post-inoculation treatments, when the sensitizer was co-applied with the fungicide at 10% of the RDR. In this case, disease reduction significantly exceeded the protective effect of Folicur® at 10% or 20% of the RDR, alone, and also a calculated additive effect. Collectively, our findings suggest that 6-DMM is promising as a putative component for formulations with triazole and strobilurin fungicides. Such new formulations would improve fungicide efficacy and, potentially, lower rates of fungicides needed for plant pathogen control.
Collapse
Affiliation(s)
- Maksim Kartashov
- Department of Molecular Biology, All-Russian Research Institute of Phytopathology, Moscow reg., Russia
| | - Tatiana Voinova
- Department of Molecular Biology, All-Russian Research Institute of Phytopathology, Moscow reg., Russia
| | - Larisa Shcherbakova
- Laboratory of Physiological Plant Pathology, All-Russian Research Institute of Phytopathology, Moscow reg., Russia
| | - Lenara Arslanova
- Department of Molecular Biology, All-Russian Research Institute of Phytopathology, Moscow reg., Russia
| | - Kseniya Chudakova
- Department of Molecular Biology, All-Russian Research Institute of Phytopathology, Moscow reg., Russia
| | - Vitaly Dzhavakhiya
- Department of Molecular Biology, All-Russian Research Institute of Phytopathology, Moscow reg., Russia
| |
Collapse
|
9
|
Accounting for heading date gene effects allows detection of small-effect QTL associated with resistance to Septoria nodorum blotch in wheat. PLoS One 2022; 17:e0268546. [PMID: 35588401 PMCID: PMC9119491 DOI: 10.1371/journal.pone.0268546] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 05/03/2022] [Indexed: 11/19/2022] Open
Abstract
In humid and temperate areas, Septoria nodorum blotch (SNB) is a major fungal disease of common wheat (Triticum aestivum L.) in which grain yield is reduced when the pathogen, Parastagonospora nodorum, infects leaves and glumes during grain filling. Foliar SNB susceptibility may be associated with sensitivity to P. nodorum necrotrophic effectors (NEs). Both foliar and glume susceptibility are quantitative, and the underlying genetics are not understood in detail. We genetically mapped resistance quantitative trait loci (QTL) to leaf and glume blotch using a double haploid (DH) population derived from the cross between the moderately susceptible cultivar AGS2033 and the resistant breeding line GA03185-12LE29. The population was evaluated for SNB resistance in the field in four successive years (2018–2021). We identified major heading date (HD) and plant height (PH) variants on chromosomes 2A and 2D, co-located with SNB escape mechanisms. Five QTL with small effects associated with adult plant resistance to SNB leaf and glume blotch were detected on 1A, 1B, and 6B linkage groups. These QTL explained a relatively small proportion of the total phenotypic variation, ranging from 5.6 to 11.8%. The small-effect QTL detected in this study did not overlap with QTL associated with morphological and developmental traits, and thus are sources of resistance to SNB.
Collapse
|
10
|
Gomez-Gutierrez SV, Goodwin SB. Loop-Mediated Isothermal Amplification for Detection of Plant Pathogens in Wheat ( Triticum aestivum). FRONTIERS IN PLANT SCIENCE 2022; 13:857673. [PMID: 35371152 PMCID: PMC8965322 DOI: 10.3389/fpls.2022.857673] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 02/17/2022] [Indexed: 05/31/2023]
Abstract
Wheat plants can be infected by a variety of pathogen species, with some of them causing similar symptoms. For example, Zymoseptoria tritici and Parastagonospora nodorum often occur together and form the Septoria leaf blotch complex. Accurate detection of wheat pathogens is essential in applying the most appropriate disease management strategy. Loop-mediated isothermal amplification (LAMP) is a recent molecular technique that was rapidly adopted for detection of plant pathogens and can be implemented easily for detection in field conditions. The specificity, sensitivity, and facility to conduct the reaction at a constant temperature are the main advantages of LAMP over immunological and alternative nucleic acid-based methods. In plant pathogen detection studies, LAMP was able to differentiate related fungal species and non-target strains of virulent species with lower detection limits than those obtained with PCR. In this review, we explain the amplification process and elements of the LAMP reaction, and the variety of techniques for visualization of the amplified products, along with their advantages and disadvantages compared with alternative isothermal approaches. Then, a compilation of analyses that show the application of LAMP for detection of fungal pathogens and viruses in wheat is presented. We also describe the modifications included in real-time and multiplex LAMP that reduce common errors from post-amplification detection in traditional LAMP assays and allow discrimination of targets in multi-sample analyses. Finally, we discuss the utility of LAMP for detection of pathogens in wheat, its limitations, and current challenges of this technique. We provide prospects for application of real-time LAMP and multiplex LAMP in the field, using portable devices that measure fluorescence and turbidity, or facilitate colorimetric detection. New technologies for detection of plant pathogen are discussed that can be integrated with LAMP to obtain elevated analytical sensitivity of detection.
Collapse
|
11
|
Saini DK, Chopra Y, Singh J, Sandhu KS, Kumar A, Bazzer S, Srivastava P. Comprehensive evaluation of mapping complex traits in wheat using genome-wide association studies. MOLECULAR BREEDING : NEW STRATEGIES IN PLANT IMPROVEMENT 2022; 42:1. [PMID: 37309486 PMCID: PMC10248672 DOI: 10.1007/s11032-021-01272-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 12/10/2021] [Indexed: 06/14/2023]
Abstract
Genome-wide association studies (GWAS) are effectively applied to detect the marker trait associations (MTAs) using whole genome-wide variants for complex quantitative traits in different crop species. GWAS has been applied in wheat for different quality, biotic and abiotic stresses, and agronomic and yield-related traits. Predictions for marker-trait associations are controlled with the development of better statistical models taking population structure and familial relatedness into account. In this review, we have provided a detailed overview of the importance of association mapping, population design, high-throughput genotyping and phenotyping platforms, advancements in statistical models and multiple threshold comparisons, and recent GWA studies conducted in wheat. The information about MTAs utilized for gene characterization and adopted in breeding programs is also provided. In the literature that we surveyed, as many as 86,122 wheat lines have been studied under various GWA studies reporting 46,940 loci. However, further utilization of these is largely limited. The future breakthroughs in area of genomic selection, multi-omics-based approaches, machine, and deep learning models in wheat breeding after exploring the complex genetic structure with the GWAS are also discussed. This is a most comprehensive study of a large number of reports on wheat GWAS and gives a comparison and timeline of technological developments in this area. This will be useful to new researchers or groups who wish to invest in GWAS.
Collapse
Affiliation(s)
- Dinesh K. Saini
- Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana, 141004 India
| | - Yuvraj Chopra
- College of Agriculture, Punjab Agricultural University, Ludhiana, 141004 India
| | - Jagmohan Singh
- Division of Plant Pathology, Indian Agricultural Research Institute, New Delhi, 110012 India
| | - Karansher S. Sandhu
- Department of Crop and Soil Sciences, Washington State University, Pullman, WA 99163 USA
| | - Anand Kumar
- Department of Genetics and Plant Breeding, Chandra Shekhar Azad University of Agriculture and Technology, Kanpur, 202002 India
| | - Sumandeep Bazzer
- Division of Plant Sciences, University of Missouri, Columbia, MO 65211 USA
| | - Puja Srivastava
- Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana, 141004 India
| |
Collapse
|
12
|
Bouvet L, Percival-Alwyn L, Berry S, Fenwick P, Mantello CC, Sharma R, Holdgate S, Mackay IJ, Cockram J. Wheat genetic loci conferring resistance to stripe rust in the face of genetically diverse races of the fungus Puccinia striiformis f. sp. tritici. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2022; 135:301-319. [PMID: 34837509 PMCID: PMC8741662 DOI: 10.1007/s00122-021-03967-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 10/05/2021] [Indexed: 05/20/2023]
Abstract
KEY MESSAGE Analysis of a wheat multi-founder population identified 14 yellow rust resistance QTL. For three of the four most significant QTL, haplotype analysis indicated resistance alleles were rare in European wheat. Stripe rust, or yellow rust (YR), is a major fungal disease of wheat (Triticum aestivum) caused by Puccinia striiformis Westend f. sp. tritici (Pst). Since 2011, the historically clonal European Pst races have been superseded by the rapid incursion of genetically diverse lineages, reducing the resistance of varieties previously showing durable resistance. Identification of sources of genetic resistance to such races is a high priority for wheat breeding. Here we use a wheat eight-founder multi-parent population genotyped with a 90,000 feature single nucleotide polymorphism array to genetically map YR resistance to such new Pst races. Genetic analysis of five field trials at three UK sites identified 14 quantitative trait loci (QTL) conferring resistance. Of these, four highly significant loci were consistently identified across all test environments, located on chromosomes 1A (QYr.niab-1A.1), 2A (QYr.niab-2A.1), 2B (QYr.niab-2B.1) and 2D (QYr.niab-2D.1), together explaining ~ 50% of the phenotypic variation. Analysis of these four QTL in two-way and three-way combinations showed combinations conferred greater resistance than single QTL, and genetic markers were developed that distinguished resistant and susceptible alleles. Haplotype analysis in a collection of wheat varieties found that the haplotypes associated with YR resistance at three of these four major loci were rare (≤ 7%) in European wheat, highlighting their potential utility for future targeted improvement of disease resistance. Notably, the physical interval for QTL QYr.niab-2B.1 contained five nucleotide-binding leucine-rich repeat candidate genes with integrated BED domains, of which two corresponded to the cloned resistance genes Yr7 and Yr5/YrSp.
Collapse
Affiliation(s)
- Laura Bouvet
- NIAB, 93 Lawrence Weaver Road, Cambridge, CB3 0LE, UK
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
| | | | | | | | | | - Rajiv Sharma
- Scotland's Rural College (SRUC), Kings Buildings, West Mains Road, Edinburgh, EH9 3JG, UK
| | | | - Ian J Mackay
- NIAB, 93 Lawrence Weaver Road, Cambridge, CB3 0LE, UK
- Scotland's Rural College (SRUC), The King's Buildings, West Mains Road, Edinburgh, EH9 3JG, UK
| | - James Cockram
- NIAB, 93 Lawrence Weaver Road, Cambridge, CB3 0LE, UK.
| |
Collapse
|
13
|
Katoch S, Sharma V, Sharma D, Salwan R, Rana SK. Biology and molecular interactions of Parastagonospora nodorum blotch of wheat. PLANTA 2021; 255:21. [PMID: 34914013 DOI: 10.1007/s00425-021-03796-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 11/14/2021] [Indexed: 06/14/2023]
Abstract
Parastagonospora nodorum is one of the important necrotrophic pathogens of wheat which causes severe economical loss to crop yield. So far, a number of effectors of Parastagonospora nodorum origin and their target interacting genes on the host plant have been characterized. Since targeting effector-sensitive gene carefully can be helpful in breeding for resistance. Therefore, constant efforts are required to further characterize the effectors, their interacting genes, and underlying biochemical pathways. Furthermore, to develop effective counter-strategies against emerging diseases, continuous efforts are required to determine the qualitative resistance that demands to screen of diverse genotypes for host resistance. Stagonospora nodorum blotch also refers to as Stagonospora glume blotch and leaf is caused by Parastagonospora nodorum. The pathogen deploys necrotrophic effectors for the establishment and development on wheat plants. The necrotrophic effectors and their interaction with host receptors lead to the establishment of infection on leaves and extensive lesions formation which either results in host cell death or suppression/activation of host defence mechanisms. The wheat Stagonospora nodorum interaction involves a set of nine host gene-necrotrophic effector interactions. Out of these, Snn1-SnTox1, Tsn1-SnToxA and Snn-SnTox3 are one of the most studied interaction, due to its role in the suppression of reactive oxygen species production, regulating the cytokinin content through ethylene-dependent wayduring initial infection stage. Further, although the molecular basis is not fully unveiled, these effectors regulate the redox state and influence the ethylene biosynthesis in infected wheat plants. Here, we have discussed the biology of the wheat pathogen Parastagonospora nodorum, role of its necrotrophic effectors and their interacting sensitivity genes on the redox state, how they hijack the resistance mechanisms, hormonal regulated immunity and other signalling pathways in susceptible wheat plants. The information generated from effectors and their corresponding sensitivity genes and other biological processes could be utilized effectively for disease management strategies.
Collapse
Affiliation(s)
- Shabnam Katoch
- Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India
| | - Vivek Sharma
- University Centre for Research and Development, Chandigarh University, Gharuan, 140413, Punjab, India.
| | - Devender Sharma
- Crop Improvement Division, ICAR-Vivekananda Parvatiya Krishi Anusandhan Sansthan, Almora, Uttarakhand, India
| | - Richa Salwan
- College of Horticulture and Forestry, Neri, Dr YS Parmar University of Horticulture and Forestry, Solan, Hamirpur, 177 001, India
| | - S K Rana
- Department of Plant Pathology, CSK HPKV Palampur, Palampur, 176062, Himachal Pradesh, India
| |
Collapse
|
14
|
Francki MG, Walker E, McMullan CJ, Morris WG. Evaluation of Septoria Nodorum Blotch (SNB) Resistance in Glumes of Wheat ( Triticum aestivum L.) and the Genetic Relationship With Foliar Disease Response. Front Genet 2021; 12:681768. [PMID: 34267781 PMCID: PMC8276050 DOI: 10.3389/fgene.2021.681768] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 06/07/2021] [Indexed: 11/13/2022] Open
Abstract
Septoria nodorum blotch (SNB) is a necrotrophic disease of wheat prominent in some parts of the world, including Western Australia (WA) causing significant losses in grain yield. The genetic mechanisms for resistance are complex involving multiple quantitative trait loci. In order to decipher comparable or independent regulation, this study identified the genetic control for glume compared to foliar resistance across four environments in WA against 37 different isolates. High proportion of the phenotypic variation across environments was contributed by genotype (84.0% for glume response and 82.7% for foliar response) with genotype-by-environment interactions accounting for a proportion of the variation for both glume and foliar response (14.7 and 16.2%, respectively). Despite high phenotypic correlation across environments, most of the eight and 14 QTL detected for glume and foliar resistance using genome wide association analysis (GWAS), respectively, were identified as environment-specific. QTL for glume and foliar resistance neither co-located nor were in LD in any particular environment indicating autonomous genetic mechanisms control SNB response in adult plants, regulated by independent biological mechanisms and influenced by significant genotype-by- environment interactions. Known Snn and Tsn loci and QTL were compared with 22 environment-specific QTL. None of the eight QTL for glume or the 14 for foliar response were co-located or in linkage disequilibrium with Snn and only one foliar QTL was in LD with Tsn loci on the physical map. Therefore, glume and foliar response to SNB in wheat is regulated by multiple environment-specific loci which function independently, with limited influence of known NE-Snn interactions for disease progression in Western Australian environments. Breeding for stable resistance would consequently rely on recurrent phenotypic selection to capture and retain favorable alleles for both glume and foliar resistance relevant to a particular environment.
Collapse
Affiliation(s)
- Michael G Francki
- Department of Primary Industries and Regional Development, South Perth, WA, Australia.,State Agricultural Biotechnology Centre, Murdoch University, Murdoch, WA, Australia
| | - Esther Walker
- Department of Primary Industries and Regional Development, South Perth, WA, Australia.,State Agricultural Biotechnology Centre, Murdoch University, Murdoch, WA, Australia
| | | | - W George Morris
- Department of Primary Industries and Regional Development, South Perth, WA, Australia
| |
Collapse
|
15
|
Malvestiti MC, Immink RGH, Arens P, Quiroz Monnens T, van Kan JAL. Fire Blight Susceptibility in Lilium spp. Correlates to Sensitivity to Botrytis elliptica Secreted Cell Death Inducing Compounds. FRONTIERS IN PLANT SCIENCE 2021; 12:660337. [PMID: 34262577 PMCID: PMC8273286 DOI: 10.3389/fpls.2021.660337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 06/01/2021] [Indexed: 06/13/2023]
Abstract
Fire blight represents a widespread disease in Lilium spp. and is caused by the necrotrophic Ascomycete Botrytis elliptica. There are >100 Lilium species that fall into distinct phylogenetic groups and these have been used to generate the contemporary commercial genotypes. It is known among lily breeders and growers that different groups of lilies differ in susceptibility to fire blight, but the genetic basis and mechanisms of susceptibility to fire blight are unresolved. The aim of this study was to quantify differences in fire blight susceptibility between plant genotypes and differences in virulence between fungal isolates. To this end we inoculated, in four biological replicates over 2 years, a set of 12 B. elliptica isolates on a panel of 18 lily genotypes representing seven Lilium hybrid groups. A wide spectrum of variation in symptom severity was observed in different isolate-genotype combinations. There was a good correlation between the lesion diameters on leaves and flowers of the Lilium genotypes, although the flowers generally showed faster expanding lesions. It was earlier postulated that B. elliptica pathogenicity on lily is conferred by secreted proteins that induce programmed cell death in lily cells. We selected two aggressive isolates and one mild isolate and collected culture filtrate (CF) samples to compare the cell death inducing activity of their secreted compounds in lily. After leaf infiltration of the CFs, variation was observed in cell death responses between the diverse lilies. The severity of cell death responses upon infiltration of the fungal CF observed among the diverse Lilium hybrid groups correlated well to their fire blight susceptibility. These results support the hypothesis that susceptibility to fire blight in lily is mediated by their sensitivity to B. elliptica effector proteins in a quantitative manner. Cell death-inducing proteins may provide an attractive tool to predict fire blight susceptibility in lily breeding programs.
Collapse
Affiliation(s)
- Michele C. Malvestiti
- Laboratory of Phytopathology, Wageningen University & Research, Wageningen, Netherlands
| | - Richard G. H. Immink
- Department of Bioscience, Wageningen University & Research, Wageningen, Netherlands
- Laboratory of Molecular Biology, Wageningen University & Research, Wageningen, Netherlands
| | - Paul Arens
- Department of Plant Breeding, Wageningen University & Research, Wageningen, Netherlands
| | - Thomas Quiroz Monnens
- Laboratory of Phytopathology, Wageningen University & Research, Wageningen, Netherlands
| | - Jan A. L. van Kan
- Laboratory of Phytopathology, Wageningen University & Research, Wageningen, Netherlands
| |
Collapse
|
16
|
AlTameemi R, Gill HS, Ali S, Ayana G, Halder J, Sidhu JS, Gill US, Turnipseed B, Hernandez JLG, Sehgal SK. Genome-wide association analysis permits characterization of Stagonospora nodorum blotch (SNB) resistance in hard winter wheat. Sci Rep 2021; 11:12570. [PMID: 34131169 PMCID: PMC8206080 DOI: 10.1038/s41598-021-91515-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Accepted: 05/24/2021] [Indexed: 11/26/2022] Open
Abstract
Stagonospora nodorum blotch (SNB) is an economically important wheat disease caused by the necrotrophic fungus Parastagonospora nodorum. SNB resistance in wheat is controlled by several quantitative trait loci (QTLs). Thus, identifying novel resistance/susceptibility QTLs is crucial for continuous improvement of the SNB resistance. Here, the hard winter wheat association mapping panel (HWWAMP) comprising accessions from breeding programs in the Great Plains region of the US, was evaluated for SNB resistance and necrotrophic effectors (NEs) sensitivity at the seedling stage. A genome-wide association study (GWAS) was performed to identify single‐nucleotide polymorphism (SNP) markers associated with SNB resistance and effectors sensitivity. We found seven significant associations for SNB resistance/susceptibility distributed over chromosomes 1B, 2AL, 2DS, 4AL, 5BL, 6BS, and 7AL. Two new QTLs for SNB resistance/susceptibility at the seedling stage were identified on chromosomes 6BS and 7AL, whereas five QTLs previously reported in diverse germplasms were validated. Allele stacking analysis at seven QTLs explained the additive and complex nature of SNB resistance. We identified accessions (‘Pioneer-2180’ and ‘Shocker’) with favorable alleles at five of the seven identified loci, exhibiting a high level of resistance against SNB. Further, GWAS for sensitivity to NEs uncovered significant associations for SnToxA and SnTox3, co-locating with previously identified host sensitivity genes (Tsn1 and Snn3). Candidate region analysis for SNB resistance revealed 35 genes of putative interest with plant defense response-related functions. The QTLs identified and validated in this study could be easily employed in breeding programs using the associated markers to enhance the SNB resistance in hard winter wheat.
Collapse
Affiliation(s)
- Rami AlTameemi
- Department of Agronomy, Horticulture and Plant Science, South Dakota State University, Brookings, SD, 57007, USA
| | - Harsimardeep S Gill
- Department of Agronomy, Horticulture and Plant Science, South Dakota State University, Brookings, SD, 57007, USA
| | - Shaukat Ali
- Department of Agronomy, Horticulture and Plant Science, South Dakota State University, Brookings, SD, 57007, USA
| | - Girma Ayana
- Department of Agronomy, Horticulture and Plant Science, South Dakota State University, Brookings, SD, 57007, USA
| | - Jyotirmoy Halder
- Department of Agronomy, Horticulture and Plant Science, South Dakota State University, Brookings, SD, 57007, USA
| | - Jagdeep S Sidhu
- Department of Agronomy, Horticulture and Plant Science, South Dakota State University, Brookings, SD, 57007, USA
| | - Upinder S Gill
- Department of Plant Pathology, North Dakota State University, Fargo, ND, 58108, USA
| | - Brent Turnipseed
- Department of Agronomy, Horticulture and Plant Science, South Dakota State University, Brookings, SD, 57007, USA
| | - Jose L Gonzalez Hernandez
- Department of Agronomy, Horticulture and Plant Science, South Dakota State University, Brookings, SD, 57007, USA
| | - Sunish K Sehgal
- Department of Agronomy, Horticulture and Plant Science, South Dakota State University, Brookings, SD, 57007, USA.
| |
Collapse
|
17
|
Downie RC, Lin M, Corsi B, Ficke A, Lillemo M, Oliver RP, Phan HTT, Tan KC, Cockram J. Septoria Nodorum Blotch of Wheat: Disease Management and Resistance Breeding in the Face of Shifting Disease Dynamics and a Changing Environment. PHYTOPATHOLOGY 2021; 111:906-920. [PMID: 33245254 DOI: 10.1094/phyto-07-20-0280-rvw] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The fungus Parastagonospora nodorum is a narrow host range necrotrophic fungal pathogen that causes Septoria nodorum blotch (SNB) of cereals, most notably wheat (Triticum aestivum). Although commonly observed on wheat seedlings, P. nodorum infection has the greatest effect on the adult crop. It results in leaf blotch, which limits photosynthesis and thus crop growth and yield. It can also affect the wheat ear, resulting in glume blotch, which directly affects grain quality. Reports of P. nodorum fungicide resistance, the increasing use of reduced tillage agronomic practices, and high evolutionary potential of the pathogen, combined with changes in climate and agricultural environments, mean that genetic resistance to SNB remains a high priority in many regions of wheat cultivation. In this review, we summarize current information on P. nodorum population structure and its implication for improved SNB management. We then review recent advances in the genetics of host resistance to P. nodorum and the necrotrophic effectors it secretes during infection, integrating the genomic positions of these genetic loci by using the recently released wheat reference genome assembly. Finally, we discuss the genetic and genomic tools now available for SNB resistance breeding and consider future opportunities and challenges in crop health management by using the wheat-P. nodorum interaction as a model.
Collapse
Affiliation(s)
- Rowena C Downie
- John Bingham Laboratory, NIAB, Cambridge, CB3 0LE, United Kingdom
- Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, United Kingdom
| | - Min Lin
- Norwegian University of Life Sciences, Ås NO-1432, Norway
| | - Beatrice Corsi
- John Bingham Laboratory, NIAB, Cambridge, CB3 0LE, United Kingdom
| | - Andrea Ficke
- Norwegian Institute for Bioeconomy Research, Ås NO-1432, Norway
| | - Morten Lillemo
- Norwegian University of Life Sciences, Ås NO-1432, Norway
| | | | - Huyen T T Phan
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley 6102, Perth, WA, Australia
| | - Kar-Chun Tan
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley 6102, Perth, WA, Australia
| | - James Cockram
- John Bingham Laboratory, NIAB, Cambridge, CB3 0LE, United Kingdom
| |
Collapse
|
18
|
Li D, Walker E, Francki M. Genes Associated with Foliar Resistance to Septoria Nodorum Blotch of Hexaploid Wheat ( Triticum aestivum L.). Int J Mol Sci 2021; 22:ijms22115580. [PMID: 34070394 PMCID: PMC8197541 DOI: 10.3390/ijms22115580] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 05/14/2021] [Accepted: 05/22/2021] [Indexed: 11/25/2022] Open
Abstract
The genetic control of host response to the fungal necrotrophic disease Septoria nodorum blotch (SNB) in bread wheat is complex, involving many minor genes. Quantitative trait loci (QTL) controlling SNB response were previously identified on chromosomes 1BS and 5BL. The aim of this study, therefore, was to align and compare the genetic map representing QTL interval on 1BS and 5BS with the reference sequence of wheat and identify resistance genes (R-genes) associated with SNB response. Alignment of QTL intervals identified significant genome rearrangements on 1BS between parents of the DH population EGA Blanco, Millewa and the reference sequence of Chinese Spring with subtle rearrangements on 5BL. Nevertheless, annotation of genomic intervals in the reference sequence were able to identify and map 13 and 12 R-genes on 1BS and 5BL, respectively. R-genes discriminated co-located QTL on 1BS into two distinct but linked loci. NRC1a and TFIID mapped in one QTL on 1BS whereas RGA and Snn1 mapped in the linked locus and all were associated with SNB resistance but in one environment only. Similarly, Tsn1 and WK35 were mapped in one QTL on 5BL with NETWORKED 1A and RGA genes mapped in the linked QTL interval. This study provided new insights on possible biochemical, cellular and molecular mechanisms responding to SNB infection in different environments and also addressed limitations of using the reference sequence to identify the full complement of functional R-genes in modern varieties.
Collapse
Affiliation(s)
- Dora Li
- State Agricultural Biotechnology Centre, Murdoch University, South St, Murdoch, WA 6150, Australia; (D.L.); (E.W.)
| | - Esther Walker
- State Agricultural Biotechnology Centre, Murdoch University, South St, Murdoch, WA 6150, Australia; (D.L.); (E.W.)
- Department of Primary Industries and Regional Development, 3 Baron Hay Ct, South Perth, WA 6151, Australia
| | - Michael Francki
- State Agricultural Biotechnology Centre, Murdoch University, South St, Murdoch, WA 6150, Australia; (D.L.); (E.W.)
- Department of Primary Industries and Regional Development, 3 Baron Hay Ct, South Perth, WA 6151, Australia
- Correspondence:
| |
Collapse
|
19
|
GWAS analysis reveals distinct pathogenicity profiles of Australian Parastagonospora nodorum isolates and identification of marker-trait-associations to septoria nodorum blotch. Sci Rep 2021; 11:10085. [PMID: 33980869 PMCID: PMC8115087 DOI: 10.1038/s41598-021-87829-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 04/05/2021] [Indexed: 12/25/2022] Open
Abstract
The fungus Parastagonospora nodorum is the causal agent of septoria nodorum leaf blotch (SNB) and glume blotch which are common in many wheat growing regions in the world. The disease is complex and could be explained by multiple interactions between necrotrophic effectors secreted by the pathogen and matching susceptibility genes in wheat. An Australian P. nodorum population was clustered into five groups with contrasting properties. This study was set to identify their pathogenicity profiles using a diverse wheat panel of 134 accessions which are insensitive to SnToxA and SnTox1 in both in vitro and in vivo conditions. SNB seedling resistance/susceptibility to five representative isolates from the five clusters, responses to crude culture-filtrates (CFs) of three isolates and sensitivity to SnTox3 semi-purified effector together with 11,455 SNP markers have been used for linkage disequilibrium (LD) and association analyses. While quantitative trait loci (QTL) on 1D, 2A, 2B, 4B, 5B, 6A, 6B, 7A, 7D chromosomes were consistently detected across isolates and conditions, distinct patterns and isolate specific QTL were also observed among these isolates. In this study, SnTox3–Snn3-B1 interaction for the first time in Australia and SnTox3–Snn3-D1 interaction for the first time in bread wheat were found active using wild-type isolates. These findings could be due to new SnTox3 haplotype/isoform and exotic CIMMYT/ICARDA and Vavilov germplasm used, respectively. This study could provide useful information for dissecting novel and different SNB disease components, helping to prioritise research targets and contributing valuable information on genetic loci/markers for marker-assisted selection in SNB resistance wheat breeding programme.
Collapse
|
20
|
Muhammad A, Li J, Hu W, Yu J, Khan SU, Khan MHU, Xie G, Wang J, Wang L. Uncovering genomic regions controlling plant architectural traits in hexaploid wheat using different GWAS models. Sci Rep 2021; 11:6767. [PMID: 33762669 PMCID: PMC7990932 DOI: 10.1038/s41598-021-86127-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Accepted: 03/10/2021] [Indexed: 01/31/2023] Open
Abstract
Wheat is a major food crop worldwide. The plant architecture is a complex trait mostly influenced by plant height, tiller number, and leaf morphology. Plant height plays a crucial role in lodging and thus affects yield and grain quality. In this study, a wheat population was genotyped by using Illumina iSelect 90K single nucleotide polymorphism (SNP) assay and finally 22,905 high-quality SNPs were used to perform a genome-wide association study (GWAS) for plant architectural traits employing four multi-locus GWAS (ML-GWAS) and three single-locus GWAS (SL-GWAS) models. As a result, 174 and 97 significant SNPs controlling plant architectural traits were detected by ML-GWAS and SL-GWAS methods, respectively. Among these SNP makers, 43 SNPs were consistently detected, including seven across multiple environments and 36 across multiple methods. Interestingly, five SNPs (Kukri_c34553_89, RAC875_c8121_1490, wsnp_Ex_rep_c66315_64480362, Ku_c5191_340, and tplb0049a09_1302) consistently detected across multiple environments and methods, played a role in modulating both plant height and flag leaf length. Furthermore, candidate SNPs (BS00068592_51, Kukri_c4750_452 and BS00022127_51) constantly repeated in different years and methods associated with flag leaf width and number of tillers. We also detected several SNPs (Jagger_c6772_80, RAC875_c8121_1490, BS00089954_51, Excalibur_01167_1207, and Ku_c5191_340) having common associations with more than one trait across multiple environments. By further appraising these GWAS methods, the pLARmEB and FarmCPU models outperformed in SNP detection compared to the other ML-GWAS and SL-GWAS methods, respectively. Totally, 152 candidate genes were found to be likely involved in plant growth and development. These finding will be helpful for better understanding of the genetic mechanism of architectural traits in wheat.
Collapse
Affiliation(s)
- Ali Muhammad
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Agriculture, Guangxi University, 100 Daxue Rd., Nanning, Guangxi, China
- College of Plant Science and Technology & Biomass and Bioenergy Research Center, Huazhong Agricultural University, Wuhan, 430070, China
- Department of Agriculture, Abdul Wali Khan University Mardan, Mardan, Pakistan
| | - Jianguo Li
- College of Plant Science and Technology & Biomass and Bioenergy Research Center, Huazhong Agricultural University, Wuhan, 430070, China
| | - Weichen Hu
- College of Plant Science and Technology & Biomass and Bioenergy Research Center, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jinsheng Yu
- College of Agriculture and Food Science, Zhejiang A&F University, Lin'an, 311300, China
| | - Shahid Ullah Khan
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, China
| | - Muhammad Hafeez Ullah Khan
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, China
| | - Guosheng Xie
- College of Plant Science and Technology & Biomass and Bioenergy Research Center, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jibin Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Agriculture, Guangxi University, 100 Daxue Rd., Nanning, Guangxi, China
| | - Lingqiang Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Agriculture, Guangxi University, 100 Daxue Rd., Nanning, Guangxi, China.
- College of Plant Science and Technology & Biomass and Bioenergy Research Center, Huazhong Agricultural University, Wuhan, 430070, China.
| |
Collapse
|
21
|
Li Q, Wang B, Yu J, Dou D. Pathogen-informed breeding for crop disease resistance. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2021; 63:305-311. [PMID: 33095498 DOI: 10.1111/jipb.13029] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/19/2020] [Indexed: 06/11/2023]
Abstract
The development of durable and broad-spectrum resistance is an economical and eco-friendly approach to control crop diseases for sustainable agricultural production. Emerging knowledge of the molecular basis of pathogenesis and plant-pathogen interactions has contributed to the development of novel pathogen-informed breeding strategies beyond the limits imposed by conventional breeding. Here, we review the current status of pathogen-assisted resistance-related gene cloning. We also describe how pathogen effector proteins can be used to identify resistance resources and to inform cultivar deployment. Finally, we summarize the main approaches for pathogen-directed plant improvement, including transgenesis and genome editing. Thus, we describe the emerging role of pathogen-related studies in the breeding of disease-resistant varieties, and propose innovative pathogen-informed strategies for future applications.
Collapse
Affiliation(s)
- Qi Li
- Jiangsu Key Laboratory for the Research and Utilization of Plant Resources, Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing, 210014, China
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Bi Wang
- Jiangsu Key Laboratory for the Research and Utilization of Plant Resources, Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing, 210014, China
| | - Jinping Yu
- Jiangsu Key Laboratory for the Research and Utilization of Plant Resources, Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing, 210014, China
| | - Daolong Dou
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
| |
Collapse
|
22
|
Lin M, Stadlmeier M, Mohler V, Tan KC, Ficke A, Cockram J, Lillemo M. Identification and cross-validation of genetic loci conferring resistance to Septoria nodorum blotch using a German multi-founder winter wheat population. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2021; 134:125-142. [PMID: 33047219 PMCID: PMC7813717 DOI: 10.1007/s00122-020-03686-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 09/12/2020] [Indexed: 05/12/2023]
Abstract
We identified allelic variation at two major loci, QSnb.nmbu-2A.1 and QSnb.nmbu-5A.1, showing consistent and additive effects on SNB field resistance. Validation of QSnb.nmbu-2A.1 across genetic backgrounds further highlights its usefulness for marker-assisted selection. Septoria nodorum blotch (SNB) is a disease of wheat (Triticum aestivum and T. durum) caused by the necrotrophic fungal pathogen Parastagonospora nodorum. SNB resistance is a typical quantitative trait, controlled by multiple quantitative trait loci (QTL) of minor effect. To achieve increased plant resistance, selection for resistance alleles and/or selection against susceptibility alleles must be undertaken. Here, we performed genetic analysis of SNB resistance using an eight-founder German Multiparent Advanced Generation Inter-Cross (MAGIC) population, termed BMWpop. Field trials and greenhouse testing were conducted over three seasons in Norway, with genetic analysis identifying ten SNB resistance QTL. Of these, two QTL were identified over two seasons: QSnb.nmbu-2A.1 on chromosome 2A and QSnb.nmbu-5A.1 on chromosome 5A. The chromosome 2A BMWpop QTL co-located with a robust SNB resistance QTL recently identified in an independent eight-founder MAGIC population constructed using varieties released in the United Kingdom (UK). The validation of this SNB resistance QTL in two independent multi-founder mapping populations, regardless of the differences in genetic background and agricultural environment, highlights the value of this locus in SNB resistance breeding. The second robust QTL identified in the BMWpop, QSnb.nmbu-5A.1, was not identified in the UK MAGIC population. Combining resistance alleles at both loci resulted in additive effects on SNB resistance. Therefore, using marker assisted selection to combine resistance alleles is a promising strategy for improving SNB resistance in wheat breeding. Indeed, the multi-locus haplotypes determined in this study provide markers for efficient tracking of these beneficial alleles in future wheat genetics and breeding activities.
Collapse
Affiliation(s)
- Min Lin
- Department of Plant Sciences, Norwegian University of Life Sciences, Post Box 5003, 1432, Ås, Norway
| | - Melanie Stadlmeier
- Bavarian State Research Center for Agriculture, Institute for Crop Science and Plant Breeding, Freising, Germany
| | - Volker Mohler
- Bavarian State Research Center for Agriculture, Institute for Crop Science and Plant Breeding, Freising, Germany
| | - Kar-Chun Tan
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley, WA, Australia
| | - Andrea Ficke
- Norwegian Institute of Bioeconomy Research, Høgskoleveien 7, 1433, Ås, Norway
| | - James Cockram
- John Bingham Laboratory, NIAB, 93 Lawrence Weaver Road, Cambridge, CB3 0LE, UK
| | - Morten Lillemo
- Department of Plant Sciences, Norwegian University of Life Sciences, Post Box 5003, 1432, Ås, Norway.
| |
Collapse
|
23
|
Scott MF, Ladejobi O, Amer S, Bentley AR, Biernaskie J, Boden SA, Clark M, Dell'Acqua M, Dixon LE, Filippi CV, Fradgley N, Gardner KA, Mackay IJ, O'Sullivan D, Percival-Alwyn L, Roorkiwal M, Singh RK, Thudi M, Varshney RK, Venturini L, Whan A, Cockram J, Mott R. Multi-parent populations in crops: a toolbox integrating genomics and genetic mapping with breeding. Heredity (Edinb) 2020; 125:396-416. [PMID: 32616877 PMCID: PMC7784848 DOI: 10.1038/s41437-020-0336-6] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 06/16/2020] [Accepted: 06/16/2020] [Indexed: 11/21/2022] Open
Abstract
Crop populations derived from experimental crosses enable the genetic dissection of complex traits and support modern plant breeding. Among these, multi-parent populations now play a central role. By mixing and recombining the genomes of multiple founders, multi-parent populations combine many commonly sought beneficial properties of genetic mapping populations. For example, they have high power and resolution for mapping quantitative trait loci, high genetic diversity and minimal population structure. Many multi-parent populations have been constructed in crop species, and their inbred germplasm and associated phenotypic and genotypic data serve as enduring resources. Their utility has grown from being a tool for mapping quantitative trait loci to a means of providing germplasm for breeding programmes. Genomics approaches, including de novo genome assemblies and gene annotations for the population founders, have allowed the imputation of rich sequence information into the descendent population, expanding the breadth of research and breeding applications of multi-parent populations. Here, we report recent successes from crop multi-parent populations in crops. We also propose an ideal genotypic, phenotypic and germplasm 'package' that multi-parent populations should feature to optimise their use as powerful community resources for crop research, development and breeding.
Collapse
Affiliation(s)
| | | | - Samer Amer
- University of Reading, Reading, RG6 6AH, UK
- Faculty of Agriculture, Alexandria University, Alexandria, 23714, Egypt
| | - Alison R Bentley
- The John Bingham Laboratory, NIAB, 93 Lawrence Weaver Road, Cambridge, CB3 0LE, UK
| | - Jay Biernaskie
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
| | - Scott A Boden
- School of Agriculture, Food and Wine, University of Adelaide, Glen Osmond, SA, 5064, Australia
| | | | | | - Laura E Dixon
- Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Carla V Filippi
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), INTA-CONICET, Nicolas Repetto y Los Reseros s/n, 1686, Hurlingham, Buenos Aires, Argentina
| | - Nick Fradgley
- The John Bingham Laboratory, NIAB, 93 Lawrence Weaver Road, Cambridge, CB3 0LE, UK
| | - Keith A Gardner
- The John Bingham Laboratory, NIAB, 93 Lawrence Weaver Road, Cambridge, CB3 0LE, UK
| | - Ian J Mackay
- SRUC, West Mains Road, Kings Buildings, Edinburgh, EH9 3JG, UK
| | | | | | - Manish Roorkiwal
- Center of Excellence in Genomics and Systems Biology, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India
| | - Rakesh Kumar Singh
- International Center for Biosaline Agriculture, Academic City, Dubai, United Arab Emirates
| | - Mahendar Thudi
- Center of Excellence in Genomics and Systems Biology, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India
| | - Rajeev Kumar Varshney
- Center of Excellence in Genomics and Systems Biology, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India
| | | | - Alex Whan
- CSIRO, GPO Box 1700, Canberra, ACT, 2601, Australia
| | - James Cockram
- The John Bingham Laboratory, NIAB, 93 Lawrence Weaver Road, Cambridge, CB3 0LE, UK
| | - Richard Mott
- UCL Genetics Institute, Gower Street, London, WC1E 6BT, UK
| |
Collapse
|
24
|
Pereira D, McDonald BA, Croll D. The Genetic Architecture of Emerging Fungicide Resistance in Populations of a Global Wheat Pathogen. Genome Biol Evol 2020; 12:2231-2244. [PMID: 32986802 PMCID: PMC7846115 DOI: 10.1093/gbe/evaa203] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/22/2020] [Indexed: 12/22/2022] Open
Abstract
Containing fungal diseases often depends on the application of fungicidal compounds. Fungicides can rapidly lose effectiveness due to the rise of resistant individuals in populations. However, the lack of knowledge about resistance mutations beyond known target genes challenges investigations into pathways to resistance. We used whole-genome sequencing data and association mapping to reveal the multilocus genetic architecture of fungicide resistance in a global panel of 159 isolates of Parastagonospora nodorum, an important fungal pathogen of wheat. We found significant differences in azole resistance among global field populations. The populations evolved distinctive combinations of resistance alleles which can interact when co-occurring in the same genetic background. We identified 34 significantly associated single nucleotide polymorphisms located in close proximity to genes associated with fungicide resistance in other fungi, including a major facilitator superfamily transporter. Using fungal colony growth rates and melanin production at different temperatures as fitness proxies, we found no evidence that resistance was constrained by genetic trade-offs. Our study demonstrates how genome-wide association studies of a global collection of pathogen strains can recapitulate the emergence of fungicide resistance. The distinct complement of resistance mutations found among populations illustrates how the evolutionary trajectory of fungicide adaptation can be complex and challenging to predict.
Collapse
Affiliation(s)
- Danilo Pereira
- Plant Pathology, Institute of Integrative Biology, ETH Zürich, Zürich, Switzerland
| | - Bruce A McDonald
- Plant Pathology, Institute of Integrative Biology, ETH Zürich, Zürich, Switzerland
| | - Daniel Croll
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| |
Collapse
|
25
|
Li X, Griffin K, Langeveld S, Frommhagen M, Underlin EN, Kabel MA, de Vries RP, Dilokpimol A. Functional Validation of Two Fungal Subfamilies in Carbohydrate Esterase Family 1 by Biochemical Characterization of Esterases From Uncharacterized Branches. Front Bioeng Biotechnol 2020; 8:694. [PMID: 32671051 PMCID: PMC7332973 DOI: 10.3389/fbioe.2020.00694] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 06/03/2020] [Indexed: 12/25/2022] Open
Abstract
The fungal members of Carbohydrate Esterase family 1 (CE1) from the CAZy database include both acetyl xylan esterases (AXEs) and feruloyl esterases (FAEs). AXEs and FAEs are essential auxiliary enzymes to unlock the full potential of feedstock. They are being used in many biotechnology applications including food and feed, pulp and paper, and biomass valorization. AXEs catalyze the hydrolysis of acetyl group from xylan, while FAEs release ferulic and other hydroxycinnamic acids from xylan and pectin. Previously, we reported a phylogenetic analysis for the fungal members of CE1, establishing five subfamilies (CE1_SF1–SF5). Currently, the characterized AXEs are in the subfamily CE1_SF1, whereas CE1_SF2 contains mainly characterized FAEs. These two subfamilies are more related to each other than to the other subfamilies and are predicted to have evolved from a common ancestor, but target substrates with a different molecular structure. In this study, four ascomycete enzymes from CE1_SF1 and SF2 were heterologously produced in Pichia pastoris and characterized with respect to their biochemical properties and substrate preference toward different model and plant biomass substrates. The selected enzymes from CE1_SF1 only exhibited AXE activity, whereas the one from CE1_SF2 possessed dual FAE/AXE activity. This dual activity enzyme also showed broad substrate specificity toward model substrates for FAE activity and efficiently released both acetic acid and ferulic acid (∼50%) from wheat arabinoxylan and wheat bran which was pre-treated with a commercial xylanase. These fungal AXEs and FAEs also showed promising biochemical properties, e.g., high stability over a wide pH range and retaining more than 80% of their residual activity at pH 6.0–9.0. These newly characterized fungal AXEs and FAEs from CE1 have high potential for biotechnological applications. In particular as an additional ingredient for enzyme cocktails to remove the ester-linked decorations which enables access for the backbone degrading enzymes. Among these novel enzymes, the dual FAE/AXE activity enzyme also supports the evolutionary relationship of CE1_SF1 and SF2.
Collapse
Affiliation(s)
- Xinxin Li
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute, Fungal Molecular Physiology, Utrecht University, Utrecht, Netherlands
| | - Kelli Griffin
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute, Fungal Molecular Physiology, Utrecht University, Utrecht, Netherlands
| | - Sandra Langeveld
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute, Fungal Molecular Physiology, Utrecht University, Utrecht, Netherlands
| | - Matthias Frommhagen
- Laboratory of Food Chemistry, Wageningen University & Research, Wageningen, Netherlands
| | - Emilie N Underlin
- Laboratory of Food Chemistry, Wageningen University & Research, Wageningen, Netherlands.,Department of Chemistry, Technical University of Denmark, Lyngby, Denmark
| | - Mirjam A Kabel
- Laboratory of Food Chemistry, Wageningen University & Research, Wageningen, Netherlands
| | - Ronald P de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute, Fungal Molecular Physiology, Utrecht University, Utrecht, Netherlands
| | - Adiphol Dilokpimol
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute, Fungal Molecular Physiology, Utrecht University, Utrecht, Netherlands
| |
Collapse
|
26
|
Lin M, Ficke A, Cockram J, Lillemo M. Genetic Structure of the Norwegian Parastagonospora nodorum Population. Front Microbiol 2020; 11:1280. [PMID: 32612592 PMCID: PMC7309014 DOI: 10.3389/fmicb.2020.01280] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 05/19/2020] [Indexed: 01/27/2023] Open
Abstract
The necrotrophic fungal pathogen Parastagonospora nodorum causes Septoria nodorum blotch (SNB), which is one of the dominating leaf blotch diseases of wheat in Norway. A total of 165 P. nodorum isolates were collected from three wheat growing regions in Norway from 2015 to 2017. These isolates, as well as nine isolates from other countries, were analyzed for genetic variation using 20 simple sequence repeat (SSR) markers. Genetic analysis of the isolate collection indicated that the P. nodorum pathogen population infecting Norwegian spring and winter wheat underwent regular sexual reproduction and exhibited a high level of genetic diversity, with no genetic subdivisions between sampled locations, years or host cultivars. A high frequency of the presence of necrotrophic effector (NE) gene SnToxA was found in Norwegian P. nodorum isolates compared to other parts of Europe, and we hypothesize that the SnToxA gene is the major virulence factor among the three known P. nodorum NE genes (SnToxA, SnTox1, and SnTox3) in the Norwegian pathogen population. While the importance of SNB has declined in much of Europe, Norway has remained as a P. nodorum hotspot, likely due at least in part to local adaptation of the pathogen population to ToxA sensitive Norwegian spring wheat cultivars.
Collapse
Affiliation(s)
- Min Lin
- Department of Plant Sciences, Faculty of Biosciences, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Andrea Ficke
- Division of Biotechnology and Plant Health, Norwegian Institute of Bioeconomy Research (NIBIO), Ås, Norway
| | - James Cockram
- John Bingham Laboratory, NIAB, Cambridge, United Kingdom
| | - Morten Lillemo
- Department of Plant Sciences, Faculty of Biosciences, Norwegian University of Life Sciences (NMBU), Ås, Norway
| |
Collapse
|
27
|
Corsi B, Percival-Alwyn L, Downie RC, Venturini L, Iagallo EM, Campos Mantello C, McCormick-Barnes C, See PT, Oliver RP, Moffat CS, Cockram J. Genetic analysis of wheat sensitivity to the ToxB fungal effector from Pyrenophora tritici-repentis, the causal agent of tan spot. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2020; 133:935-950. [PMID: 31915874 PMCID: PMC7021774 DOI: 10.1007/s00122-019-03517-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 12/17/2019] [Indexed: 05/05/2023]
Abstract
Genetic mapping of sensitivity to the Pyrenophora tritici-repentis effector ToxB allowed development of a diagnostic genetic marker, and investigation of wheat pedigrees allowed transmission of sensitive alleles to be tracked. Tan spot, caused by the necrotrophic fungal pathogen Pyrenophora tritici-repentis, is a major disease of wheat (Triticum aestivum). Secretion of the P. tritici-repentis effector ToxB is thought to play a part in mediating infection, causing chlorosis of plant tissue. Here, genetic analysis using an association mapping panel (n = 480) and a multiparent advanced generation intercross (MAGIC) population (n founders = 8, n progeny = 643) genotyped with a 90,000 feature single nucleotide polymorphism (SNP) array found ToxB sensitivity to be highly heritable (h2 ≥ 0.9), controlled predominantly by the Tsc2 locus on chromosome 2B. Genetic mapping of Tsc2 delineated a 1921-kb interval containing 104 genes in the reference genome of ToxB-insensitive variety 'Chinese Spring'. This allowed development of a co-dominant genetic marker for Tsc2 allelic state, diagnostic for ToxB sensitivity in the association mapping panel. Phenotypic and genotypic analysis in a panel of wheat varieties post-dated the association mapping panel further supported the diagnostic nature of the marker. Combining ToxB phenotype and genotypic data with wheat pedigree datasets allowed historic sources of ToxB sensitivity to be tracked, finding the variety 'Maris Dove' to likely be the historic source of sensitive Tsc2 alleles in the wheat germplasm surveyed. Exploration of the Tsc2 region gene space in the ToxB-sensitive line 'Synthetic W7984' identified candidate genes for future investigation. Additionally, a minor ToxB sensitivity QTL was identified on chromosome 2A. The resources presented here will be of immediate use for marker-assisted selection for ToxB insensitivity and the development of germplasm with additional genetic recombination within the Tsc2 region.
Collapse
Affiliation(s)
- Beatrice Corsi
- John Bingham Laboratory, NIAB, Huntingdon Road, Cambridge, CB3 0LE, UK
| | | | - Rowena C Downie
- John Bingham Laboratory, NIAB, Huntingdon Road, Cambridge, CB3 0LE, UK
- Plant Sciences Department, University of Cambridge, Cambridge, UK
| | - Luca Venturini
- Life Sciences Department, Natural History Museum, Cromwell Road, London, SW7 5BD, UK
| | - Elyce M Iagallo
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Perth, Australia
| | - Camila Campos Mantello
- John Bingham Laboratory, NIAB, Huntingdon Road, Cambridge, CB3 0LE, UK
- Genetracer Biotech, Calle Albert Einstein 22, 39011, Santander, Spain
| | - Charlie McCormick-Barnes
- John Bingham Laboratory, NIAB, Huntingdon Road, Cambridge, CB3 0LE, UK
- Faculty of Biology, Medicine and Health, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Pao Theen See
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Perth, Australia
| | - Richard P Oliver
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Perth, Australia
| | - Caroline S Moffat
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Perth, Australia.
| | - James Cockram
- John Bingham Laboratory, NIAB, Huntingdon Road, Cambridge, CB3 0LE, UK.
| |
Collapse
|
28
|
Lin M, Corsi B, Ficke A, Tan KC, Cockram J, Lillemo M. Genetic mapping using a wheat multi-founder population reveals a locus on chromosome 2A controlling resistance to both leaf and glume blotch caused by the necrotrophic fungal pathogen Parastagonospora nodorum. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2020; 133:785-808. [PMID: 31996971 PMCID: PMC7021668 DOI: 10.1007/s00122-019-03507-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 12/10/2019] [Indexed: 05/19/2023]
Abstract
KEY MESSAGE A locus on wheat chromosome 2A was found to control field resistance to both leaf and glume blotch caused by the necrotrophic fungal pathogen Parastagonospora nodorum. The necrotrophic fungal pathogen Parastagonospora nodorum is the causal agent of Septoria nodorum leaf blotch and glume blotch, which are common wheat (Triticum aestivum L.) diseases in humid and temperate areas. Susceptibility to Septoria nodorum leaf blotch can partly be explained by sensitivity to corresponding P. nodorum necrotrophic effectors (NEs). Susceptibility to glume blotch is also quantitative; however, the underlying genetics have not been studied in detail. Here, we genetically map resistance/susceptibility loci to leaf and glume blotch using an eight-founder wheat multiparent advanced generation intercross population. The population was assessed in six field trials across two sites and 4 years. Seedling infiltration and inoculation assays using three P. nodorum isolates were also carried out, in order to compare quantitative trait loci (QTL) identified under controlled conditions with those identified in the field. Three significant field resistance QTL were identified on chromosomes 2A and 6A, while four significant seedling resistance QTL were detected on chromosomes 2D, 5B and 7D. Among these, QSnb.niab-2A.3 for field resistance to both leaf blotch and glume blotch was detected in Norway and the UK. Colocation with a QTL for seedling reactions against culture filtrate from a Norwegian P. nodorum isolate indicated the QTL could be caused by a novel NE sensitivity. The consistency of this QTL for leaf blotch at the seedling and adult plant stages and culture filtrate infiltration was confirmed by haplotype analysis. However, opposite effects for the leaf blotch and glume blotch reactions suggest that different genetic mechanisms may be involved.
Collapse
Affiliation(s)
- Min Lin
- Department of Plant Sciences, Norwegian University of Life Sciences, Post Box 5003, 1432, Ås, Norway
| | - Beatrice Corsi
- John Bingham Laboratory, NIAB, Huntingdon Road, Cambridge, CB3 0LE, UK
| | - Andrea Ficke
- Norwegian Institute of Bioeconomy Research, Høgskoleveien 7, 1433, Ås, Norway
| | - Kar-Chun Tan
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley, WA, Australia
| | - James Cockram
- John Bingham Laboratory, NIAB, Huntingdon Road, Cambridge, CB3 0LE, UK
| | - Morten Lillemo
- Department of Plant Sciences, Norwegian University of Life Sciences, Post Box 5003, 1432, Ås, Norway.
| |
Collapse
|
29
|
Cowger C, Ward B, Brown-Guedira G, Brown JKM. Role of Effector-Sensitivity Gene Interactions and Durability of Quantitative Resistance to Septoria Nodorum Blotch in Eastern U.S. Wheat. FRONTIERS IN PLANT SCIENCE 2020; 11:155. [PMID: 32210986 PMCID: PMC7067980 DOI: 10.3389/fpls.2020.00155] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 01/31/2020] [Indexed: 05/02/2023]
Abstract
Important advances have been made in understanding the relationship of necrotrophic effectors (NE) and host sensitivity (Snn) genes in the Parastagonospora nodorum-wheat pathosystem. Yet much remains to be learned about the role of these interactions in determining wheat resistance levels in the field, and there is mixed evidence on whether breeding programs have selected against Snn genes due to their role in conferring susceptibility. SNB occurs ubiquitously in the U.S. Atlantic seaboard, and the environment is especially well suited to field studies of resistance to natural P. nodorum populations, as there are no other important wheat leaf blights. Insights into the nature of SNB resistance have been gleaned from multi-year data on phenotypes and markers in cultivars representative of the region's germplasm. In this perspective article, we review the evidence that in this eastern region of the U.S., wheat cultivars have durable quantitative SNB resistance and Snn-NE interactions are of limited importance. This conclusion is discussed in light of the relevant available information from other parts of the world.
Collapse
Affiliation(s)
- Christina Cowger
- U.S. Department of Agriculture – Agricultural Research Service, North Carolina State University, Raleigh, NC, United States
- *Correspondence: Christina Cowger,
| | - Brian Ward
- U.S. Department of Agriculture – Agricultural Research Service, North Carolina State University, Raleigh, NC, United States
| | - Gina Brown-Guedira
- U.S. Department of Agriculture – Agricultural Research Service, North Carolina State University, Raleigh, NC, United States
| | - James K. M. Brown
- Department of Crop Genetics, John Innes Centre, Norwich, United Kingdom
| |
Collapse
|
30
|
Ruud AK, Dieseth JA, Ficke A, Furuki E, Phan HTT, Oliver RP, Tan KC, Lillemo M. Genome-Wide Association Mapping of Resistance to Septoria Nodorum Leaf Blotch in a Nordic Spring Wheat Collection. THE PLANT GENOME 2019; 12:1-15. [PMID: 33016591 DOI: 10.3835/plantgenome2018.12.0105] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 05/06/2019] [Indexed: 05/12/2023]
Abstract
First genome-wide association mapping of adult plant Septoria nodorum blotch resistance. Some adult plant resistance loci were shared with seedling resistance loci. Other adult plant resistance loci were significant across environments. Resistant haplotypes were identified, which can be used for breeding. Parastagonospora nodorum is the causal agent of Septoria nodorum leaf blotch (SNB) in wheat (Triticum aestivum L.). It is the most important leaf blotch pathogen in Norwegian spring wheat. Several quantitative trait loci (QTL) for SNB susceptibility have been identified. Some of these QTL are the result of underlying gene-for-gene interactions involving necrotrophic effectors (NEs) and corresponding sensitivity (Snn) genes. A collection of diverse spring wheat lines was evaluated for SNB resistance and susceptibility over seven growing seasons in the field. In addition, wheat seedlings were inoculated and infiltrated with culture filtrates (CFs) from four single spore isolates and infiltrated with semipurified NEs (SnToxA, SnTox1, and SnTox3) under greenhouse conditions. In adult plants, the most stable SNB resistance QTL were located on chromosomes 2B, 2D, 4A, 4B, 5A, 6B, 7A, and 7B. The QTL on chromosome 2D was effective most years in the field. At the seedling stage, the most significant QTL after inoculation were located on chromosomes 1A, 1B, 3A, 4B, 5B, 6B, 7A, and 7B. The QTL on chromosomes 3A and 6B were significant both after inoculation and CF infiltration, indicating the presence of novel NE-Snn interactions. The QTL on chromosomes 4B and 7A were significant in both seedlings and adult plants. Correlations between SnToxA sensitivity and disease severity in the field were significant. To our knowledge, this is the first genome-wide association mapping study (GWAS) to investigate SNB resistance at the adult plant stage under field conditions.
Collapse
Affiliation(s)
- Anja Karine Ruud
- Dep. of Plant Sciences, Norwegian Univ. of Life Sciences, Post Box 5003, NO-1432, ÅS, Norway
- Faculty of Science and Technology, Dep. of Molecular Biology and Genetics, Aarhus Univ, 4200, Slagelse, Denmark
| | - Jon Arne Dieseth
- Graminor, AS, Bjørke Gård, Hommelstadvegen 60, NO-2322, Ridabu, Norway
| | - Andrea Ficke
- Division of Biotechnology and Plant Health, Norwegian Inst. of Bioeconomy Research, P.O. Box 115, NO-1431, ÅS, Norway
| | - Eiko Furuki
- Centre for Crop and Disease Management, Dep. of Environment & Agriculture, Curtin Univ., Bentley, Western Australia, Australia
| | - Huyen T T Phan
- Centre for Crop and Disease Management, Dep. of Environment & Agriculture, Curtin Univ., Bentley, Western Australia, Australia
| | - Richard P Oliver
- Centre for Crop and Disease Management, Dep. of Environment & Agriculture, Curtin Univ., Bentley, Western Australia, Australia
| | - Kar-Chun Tan
- Centre for Crop and Disease Management, Dep. of Environment & Agriculture, Curtin Univ., Bentley, Western Australia, Australia
| | - Morten Lillemo
- Dep. of Plant Sciences, Norwegian Univ. of Life Sciences, Post Box 5003, NO-1432, ÅS, Norway
| |
Collapse
|
31
|
Prasad P, Savadi S, Bhardwaj SC, Gangwar OP, Kumar S. Rust pathogen effectors: perspectives in resistance breeding. PLANTA 2019; 250:1-22. [PMID: 30980247 DOI: 10.1007/s00425-019-03167-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 04/09/2019] [Indexed: 06/09/2023]
Abstract
Identification and functional characterization of plant pathogen effectors promise to ameliorate future research and develop effective and sustainable strategies for controlling or containing crop diseases. Wheat is the second most important food crop of the world after rice. Rust pathogens, one of the major biotic stresses in wheat production, are capable of threatening the world food security. Understanding the molecular basis of plant-pathogen interactions is essential for devising novel strategies for resistance breeding and disease management. Now, it has been established that effectors, the proteins secreted by pathogens, play a key role in plant-pathogen interactions. Therefore, effector biology has emerged as one of the most important research fields in plant biology. Recent advances in genomics and bioinformatics have allowed identification of a large repertoire of candidate effectors, while the evolving high-throughput tools have continued to assist in their functional characterization. The repertoires of effectors have become an important resource for better understanding of effector biology of pathosystems and resistance breeding of crop plants. In recent years, a significant progress has been made in the field of rust effector biology. This review describes the recent advances in effector biology of obligate fungal pathogens, identification and functional analysis of wheat rust pathogens effectors and the potential applications of effectors in molecular plant biology and rust resistance breeding in wheat.
Collapse
Affiliation(s)
- Pramod Prasad
- ICAR-Indian Institute of Wheat and Barley Research, Regional Station, Shimla, Himachal Pradesh, 171002, India
| | - Siddanna Savadi
- ICAR-Directorate of Cashew Research, Puttur, Karnataka, 574202, India
| | - S C Bhardwaj
- ICAR-Indian Institute of Wheat and Barley Research, Regional Station, Shimla, Himachal Pradesh, 171002, India.
| | - O P Gangwar
- ICAR-Indian Institute of Wheat and Barley Research, Regional Station, Shimla, Himachal Pradesh, 171002, India
| | - Subodh Kumar
- ICAR-Indian Institute of Wheat and Barley Research, Regional Station, Shimla, Himachal Pradesh, 171002, India
| |
Collapse
|
32
|
Lorang J. Necrotrophic Exploitation and Subversion of Plant Defense: A Lifestyle or Just a Phase, and Implications in Breeding Resistance. PHYTOPATHOLOGY 2019; 109:332-346. [PMID: 30451636 DOI: 10.1094/phyto-09-18-0334-ia] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Breeding disease-resistant plants is a critical, environmentally friendly component of any strategy to sustainably feed and clothe the 9.8 billion people expected to live on Earth by 2050. Here, I review current literature detailing plant defense responses as they relate to diverse biological outcomes; disease resistance, susceptibility, and establishment of mutualistic plant-microbial relationships. Of particular interest is the degree to which these outcomes are a function of plant-associated microorganisms' lifestyles; biotrophic, hemibiotrophic, necrotrophic, or mutualistic. For the sake of brevity, necrotrophic pathogens and the necrotrophic phase of pathogenicity are emphasized in this review, with special attention given to the host-specific pathogens that exploit defense. Defense responses related to generalist necrotrophs and mutualists are discussed in the context of excellent reviews by others. In addition, host evolutionary trade-offs of disease resistance with other desirable traits are considered in the context of breeding for durable disease resistance.
Collapse
Affiliation(s)
- Jennifer Lorang
- Department of Botany, 2082 Cordley Hall, Oregon State University, Corvallis 97331
| |
Collapse
|
33
|
See PT, Iagallo EM, Oliver RP, Moffat CS. Heterologous Expression of the Pyrenophora tritici-repentis Effector Proteins ToxA and ToxB, and the Prevalence of Effector Sensitivity in Australian Cereal Crops. Front Microbiol 2019; 10:182. [PMID: 30809209 PMCID: PMC6379657 DOI: 10.3389/fmicb.2019.00182] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 01/23/2019] [Indexed: 12/05/2022] Open
Abstract
Here, we evaluate the expression of the proteinaceous effectors ToxA and ToxB, produced by the necrotrophic fungal pathogen Pyrenophora tritici-repentis, which confer tan spot disease susceptibility on wheat. These necrotrophic effectors were expressed in two heterologous systems: Escherichia coli and Pichia pastoris. The E. coli SHuffle system was demonstrated to be superior to P. pastoris in generating high-levels of recombinant proteins that were soluble and stable. In addition, protein extracts from P. pastoris induced non-specific chlorosis on wheat, postulated to be caused by co-purified glucanases secreted by the host. Up to 79.6 μg/ml of ToxB was obtained using the SHuffle system in the absence of the native signal peptide, whilst the ToxA yield was considerably lower at 3.2 μg/ml. Results indicated that a histidine tag at the ToxA C-terminus interfered with effector functionality. Heterologously expressed ToxA and ToxB were tested on a panel of Australian cereals, including 122 varieties of bread wheat, 16 durum, 20 triticale and 5 barley varieties, as well as common plant model species including tobacco and Arabidopsis thaliana. A varying degree of effector sensitivities was observed, with a higher ToxB sensitivity and prevalence in the durum and triticale varieties. ToxB-induced chlorosis was also detected on barley. The heterologous expression of effectors that are easily scalable, will facilitate effector-assisted selection of varieties in wheat breeding programs as well as the investigation of P. tritici-repentis effectors in host and non-host interactions.
Collapse
Affiliation(s)
| | | | | | - Caroline S. Moffat
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley, WA, Australia
| |
Collapse
|