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Lu J, Liu Y, Song M, Xi Y, Yang H, Liu W, Li X, Norvienyeku J, Zhang Y, Miao W, Lin C. The CsPbs2-interacting protein oxalate decarboxylase CsOxdC3 modulates morphosporogenesis, virulence, and fungicide resistance in Colletotrichum siamense. Microbiol Res 2024; 284:127732. [PMID: 38677265 DOI: 10.1016/j.micres.2024.127732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 04/07/2024] [Accepted: 04/18/2024] [Indexed: 04/29/2024]
Abstract
The HOG MAPK pathway mediates diverse cellular and physiological processes, including osmoregulation and fungicide sensitivity, in phytopathogenic fungi. However, the molecular mechanisms underlying HOG MAPK pathway-associated stress homeostasis and pathophysiological developmental events are poorly understood. Here, we demonstrated that the oxalate decarboxylase CsOxdC3 in Colletotrichum siamense interacts with the protein kinase kinase CsPbs2, a component of the HOG MAPK pathway. The expression of the CsOxdC3 gene was significantly suppressed in response to phenylpyrrole and tebuconazole fungicide treatments, while that of CsPbs2 was upregulated by phenylpyrrole and not affected by tebuconazole. We showed that targeted gene deletion of CsOxdC3 suppressed mycelial growth, reduced conidial length, and triggered a marginal reduction in the sporulation characteristics of the ΔCsOxdC3 strains. Interestingly, the ΔCsOxdC3 strain was significantly sensitive to fungicides, including phenylpyrrole and tebuconazole, while the CsPbs2-defective strain was sensitive to tebuconazole but resistant to phenylpyrrole. Additionally, infection assessment revealed a significant reduction in the virulence of the ΔCsOxdC3 strains when inoculated on the leaves of rubber tree (Hevea brasiliensis). From these observations, we inferred that CsOxdC3 crucially modulates HOG MAPK pathway-dependent processes, including morphogenesis, stress homeostasis, fungicide resistance, and virulence, in C. siamense by facilitating direct physical interactions with CsPbs2. This study provides insights into the molecular regulators of the HOG MAPK pathway and underscores the potential of deploying OxdCs as potent targets for developing fungicides.
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Affiliation(s)
- Jingwen Lu
- Sanya Institute of Breeding and Multiplication / Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Ministry of Education) / School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Yu Liu
- Sanya Institute of Breeding and Multiplication / Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Ministry of Education) / School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Miao Song
- Sanya Institute of Breeding and Multiplication / Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Ministry of Education) / School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Yitao Xi
- Sanya Institute of Breeding and Multiplication / Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Ministry of Education) / School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Hong Yang
- Sanya Institute of Breeding and Multiplication / Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Ministry of Education) / School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China; Rubber Research Institute, Chinese Academy of Tropical Agricultural Science, Haikou 571101, China
| | - Wenbo Liu
- Sanya Institute of Breeding and Multiplication / Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Ministry of Education) / School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Xiao Li
- Sanya Institute of Breeding and Multiplication / Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Ministry of Education) / School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Justice Norvienyeku
- Sanya Institute of Breeding and Multiplication / Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Ministry of Education) / School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Yu Zhang
- Sanya Institute of Breeding and Multiplication / Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Ministry of Education) / School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Weiguo Miao
- Sanya Institute of Breeding and Multiplication / Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Ministry of Education) / School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Chunhua Lin
- Sanya Institute of Breeding and Multiplication / Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Ministry of Education) / School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China.
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Baran B, Ölmez F, Çapa B, Dikilitas M. Defense Pathways of Wheat Plants Inoculated with Zymoseptoria tritici under NaCl Stress Conditions: An Overview. Life (Basel) 2024; 14:648. [PMID: 38792668 PMCID: PMC11122936 DOI: 10.3390/life14050648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 04/27/2024] [Accepted: 05/08/2024] [Indexed: 05/26/2024] Open
Abstract
Due to being sessile, plants develop a broad range of defense pathways when they face abiotic or biotic stress factors. Although plants are subjected to more than one type of stress at a time in nature, the combined effects of either multiple stresses of one kind (abiotic or biotic) or more kinds (abiotic and biotic) have now been realized in agricultural lands due to increases in global warming and environmental pollution, along with population increases. Soil-borne pathogens, or pathogens infecting aerial parts, can have devastating effects on plants when combined with other stressors. Obtaining yields or crops from sensitive or moderately resistant plants could be impossible, and it could be very difficult from resistant plants. The mechanisms of combined stress in many plants have previously been studied and elucidated. Recent studies proposed new defense pathways and mechanisms through signaling cascades. In light of these mechanisms, it is now time to develop appropriate strategies for crop protection under multiple stress conditions. This may involve using disease-resistant or stress-tolerant plant varieties, implementing proper irrigation and drainage practices, and improving soil quality. However, generation of both stress-tolerant and disease-resistant crop plants is of crucial importance. The establishment of a database and understanding of the defense mechanisms under combined stress conditions would be meaningful for the development of resistant and tolerant plants. It is clear that leaf pathogens show great tolerance to salinity stress and result in pathogenicity in crop plants. We noticed that regulation of the stomata through biochemical applications and some effort with the upregulation of the minor gene expressions indirectly involved with the defense mechanisms could be a great way to increase the defense metabolites without interfering with quality parameters. In this review, we selected wheat as a model plant and Zymoseptoria tritici as a model leaf pathogen to evaluate the defense mechanisms under saline conditions through physiological, biochemical, and molecular pathways and suggested various ways to generate tolerant and resistant cereal plants.
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Affiliation(s)
- Behzat Baran
- Plant Protection Research Institute, Sur, Diyarbakır 21110, Türkiye;
| | - Fatih Ölmez
- Department of Plant Protection, Faculty of Agriculture, Sivas University of Science and Technology, Sivas 58010, Türkiye;
| | - Beritan Çapa
- Department of Plant Protection Şanliurfa, Faculty of Agriculture, Harran University, Sanliurfa 63000, Türkiye;
| | - Murat Dikilitas
- Department of Plant Protection Şanliurfa, Faculty of Agriculture, Harran University, Sanliurfa 63000, Türkiye;
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Zhang Y, Zhu M, Wang H, Yu G, Guo A, Ren W, Li B, Liu N. The Mitogen-Activated Protein Kinase Hog1 Regulates Fungal Development, Pathogenicity, and Stress Response in Botryosphaeria dothidea. PHYTOPATHOLOGY 2024; 114:725-731. [PMID: 37889135 DOI: 10.1094/phyto-07-23-0260-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
The high-osmolarity glycerol mitogen-activated protein kinase (HOG-MAPK) pathway plays a central role in environmental stress adaptation in eukaryotes. However, the biological function of the HOG-MAPK pathway varies in different fungi. In this study, we investigated the HOG-MAPK pathway by inactivation of the core element Hog1 in Botryosphaeria dothidea, the causal agent of Botryosphaeria canker and apple ring rot. Targeted deletion of BdHOG1 resulted in the loss of conidiation ability and significant reduction of virulence. In addition, the ΔBdHog1 mutant exhibited hypersensitivity to osmotic stress but resistance to phenylpyrrole and dicarboximide fungicides. Comparative transcriptome analysis revealed that inactivation of BdHog1 influenced multiple metabolic pathways in B. dothidea. Taken together, our results suggest that BdHog1 plays a crucial role in development, virulence, and stress tolerance in B. dothidea, which provides a theoretical basis for the development of target-based fungicides.
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Affiliation(s)
- Yihan Zhang
- Key Laboratory of Integrated Crop Pest Management of Shandong Province, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao 266109, China
| | - Meiqi Zhu
- Key Laboratory of Integrated Crop Pest Management of Shandong Province, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao 266109, China
| | - Hongna Wang
- Key Laboratory of Integrated Crop Pest Management of Shandong Province, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao 266109, China
| | - Guolei Yu
- Key Laboratory of Integrated Crop Pest Management of Shandong Province, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao 266109, China
| | - Anqi Guo
- Key Laboratory of Integrated Crop Pest Management of Shandong Province, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao 266109, China
| | - Weichao Ren
- Key Laboratory of Integrated Crop Pest Management of Shandong Province, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao 266109, China
| | - Baohua Li
- Key Laboratory of Integrated Crop Pest Management of Shandong Province, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao 266109, China
| | - Na Liu
- Key Laboratory of Integrated Crop Pest Management of Shandong Province, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao 266109, China
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Kovács-Simon A, Fones HN. Use of chitin:DNA ratio to assess growth form in fungal cells. BMC Biol 2024; 22:10. [PMID: 38233847 PMCID: PMC10795418 DOI: 10.1186/s12915-024-01815-2] [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: 11/09/2023] [Accepted: 01/04/2024] [Indexed: 01/19/2024] Open
Abstract
BACKGROUND Dimorphism, the ability to switch between a 'yeast-like' and a hyphal growth form, is an important feature of certain fungi, including important plant and human pathogens. The switch to hyphal growth is often associated with virulence, pathogenicity, biofilm formation and stress resistance. Thus, the ability to accurately and efficiently measure fungal growth form is key to research into these fungi, especially for discovery of potential drug targets. To date, fungal growth form has been assessed microscopically, a process that is both labour intensive and costly. RESULTS Here, we unite quantification of the chitin in fungal cell walls and the DNA in nuclei to produce a methodology that allows fungal cell shape to be estimated by calculation of the ratio between cell wall quantity and number of nuclei present in a sample of fungus or infected host tissue. Using the wheat pathogen Zymoseptoria tritici as a test case, with confirmation in the distantly related Fusarium oxysporum, we demonstrate a close, linear relationship between the chitin:DNA ratio and the average polarity index (length/width) of fungal cells. We show the utility of the method for estimating growth form in infected wheat leaves, differentiating between the timing of germination in two different Z. tritici isolates using this ratio. We also show that the method is robust to the occurrence of thick-walled chlamydospores, which show a chitin:DNA ratio that is distinct from either 'yeast-like' blastospores or hyphae. CONCLUSIONS The chitin:DNA ratio provides a simple methodology for determining fungal growth form in bulk tissue samples, reducing the need for labour-intensive microscopic studies requiring specific staining or GFP-tags to visualise the fungus within host tissues. It is applicable to a range of dimorphic fungi under various experimental conditions.
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Stapley J, McDonald BA. Quantitative trait locus mapping of osmotic stress response in the fungal wheat pathogen Zymoseptoria tritici. G3 (BETHESDA, MD.) 2023; 13:jkad226. [PMID: 37774498 PMCID: PMC10700024 DOI: 10.1093/g3journal/jkad226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 09/19/2023] [Accepted: 09/20/2023] [Indexed: 10/01/2023]
Abstract
Osmotic stress is a ubiquitous and potent stress for all living organisms, but few studies have investigated the genetic basis of salt tolerance in filamentous fungi. The main aim of this study was to identify regions of the genome associated with tolerance to potassium chloride (KCl) in the wheat pathogen Zymoseptoria tritici. A secondary aim was to identify candidate genes affecting salt tolerance within the most promising chromosomal regions. We achieved these aims with a quantitative trait locus (QTL) mapping study using offspring from 2 crosses grown in vitro in the presence or absence of osmotic stress imposed by 0.75 M KCl. We identified significant QTL for most of the traits in both crosses. Several QTLs overlapped with QTL identified in earlier studies for other traits, and some QTL explained trait variation in both the control and salt stress environments. A significant QTL on chromosome 3 explained variation in colony radius at 8-day postinoculation (dpi) in the KCl environment as well as colony radius KCl tolerance at 8 dpi. The QTL peak had a high logarithm of the odds ratio (LOD) and encompassed an interval containing only 36 genes. Six of these genes present promising candidates for functional analyses. A gene ontology (GO) enrichment analysis of QTL unique to the KCl environment found evidence for the enrichment of functions involved in osmotic stress responses.
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Affiliation(s)
- Jessica Stapley
- Plant Pathology Group, Institute of Integrative Biology, ETH Zurich, Zürich 8092, Switzerland
| | - Bruce A McDonald
- Plant Pathology Group, Institute of Integrative Biology, ETH Zurich, Zürich 8092, Switzerland
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Jia W, Yu H, Fan J, Zhang J, Su L, Li D, Pan H, Zhang X. Crucial Roles of the High-Osmolarity Glycerol Pathway in the Antifungal Activity of Isothiocyanates against Cochliobolus heterostrophus. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:15466-15475. [PMID: 37877171 DOI: 10.1021/acs.jafc.3c04853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2023]
Abstract
Isothiocyanates (ITCs) that are found in Brassicaceae exhibited obvious antifungal activity against Cochliobolus heterostrophus, which is the causal agent of southern corn leaf blight. However, the underlying antifungal mechanism of allyl-ITCs (A-ITCs) against C. heterostrophus remains largely unknown. Here, we used transcriptomic analysis to find that the high osmolarity pathway was upregulated significantly when treated with A-ITCs. To investigate the roles of the high osmolarity pathway in adaption to A-ITCs, we constructed Δssk2, Δpbs2, and Δhog1 mutant strains. Deletion of three genes (ChSSK2, ChPBS2, and ChHOG1) involved in the high osmolarity pathway resulted in significantly increased sensitivity of C. heterostrophus to ITCs. In addition, the phosphorylation level of ChHog1 was induced by A-ITC and was dependent on the presence of ChSsk2 and ChPbs2. Moreover, Δssk2, Δpbs2, and Δhog1 mutants exhibited a dramatically decreased virulence on maize leaves. Our findings demonstrated that the high osmolarity pathway played a positive role in ITC tolerance and virulence, which may provide novel insights into developing ITCs as a new fungicide against C. heterostrophus.
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Affiliation(s)
- Wantong Jia
- College of Plant Science, Jilin University, Changchun 130062, China
| | - Huilin Yu
- College of Plant Science, Jilin University, Changchun 130062, China
| | - Jinyu Fan
- College of Plant Science, Jilin University, Changchun 130062, China
| | - Jiyue Zhang
- College of Plant Science, Jilin University, Changchun 130062, China
| | - Longhao Su
- College of Plant Science, Jilin University, Changchun 130062, China
| | - Dan Li
- College of Plant Science, Jilin University, Changchun 130062, China
| | - Hongyu Pan
- College of Plant Science, Jilin University, Changchun 130062, China
| | - Xianghui Zhang
- College of Plant Science, Jilin University, Changchun 130062, China
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Ababa G. Biology, taxonomy, genetics, and management of Zymoseptoria tritici: the causal agent of wheat leaf blotch. Mycology 2023; 14:292-315. [PMID: 38187886 PMCID: PMC10769150 DOI: 10.1080/21501203.2023.2241492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 07/22/2023] [Indexed: 01/09/2024] Open
Abstract
Septoria tritici blotch or Septoria leaf blotch has been used for long time, but leaf blotch is a correct disease name. Moreover, Lb resistant gene is the correct name, but, not Stb gene. It has sexual and asexual parts on the mycelia, known as heterothallic fungi. Its pathogenic diversity ranged from 40% to 93% and has produced a wide variety of AvrLb6 haplotypes. M. graminicola has a plasmogamy and karyogamy sexual process. The pathogen can use macropycnidiospores, micropycnidiospores, and pycnidia vegetative growths for infection and overwintering. Synthetic M3, Kavkaz-K4500, Synthetic 6×, and TE9111 wheat genotypes have horizontal resistance. Avirulence (Avr) genes in Z. tritici and their matching wheat (R) genes indicate gene for gene mechanisms of resistance. Twenty-two R genes (vertical resistance) have been identified. In both horizontal and vertical resistance, different Lb genes have been broken down due to new Z.tritici virulent gene and currently Lb19 resistant gene is being recommended. Mixing of resistant and susceptible cultivars is also the most effective management strategy. Moreover, different cultural practices and biological control have been proposed. Lastly, different fungicides are also available. However, in developing countries cultivar mixture, isolates diversity, biological control, and epidemic studies have been greatly missed.
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Affiliation(s)
- Girma Ababa
- Department of Plant Protection (Plant Pathology), Holetta Agricultural Research Center (HARC), Ethiopian Institute of Agricultural Research (EIAR), Holetta, Addis Ababa, Ethiopia
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Francisco CS, McDonald BA, Palma-Guerrero J. A transcription factor and a phosphatase regulate temperature-dependent morphogenesis in the fungal plant pathogen Zymoseptoria tritici. Fungal Genet Biol 2023; 167:103811. [PMID: 37196910 DOI: 10.1016/j.fgb.2023.103811] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 04/26/2023] [Accepted: 05/10/2023] [Indexed: 05/19/2023]
Abstract
Naturally fluctuating temperatures provide a constant environmental stress that requires adaptation. Some fungal pathogens respond to heat stress by producing new morphotypes that maximize their overall fitness. The fungal wheat pathogen Zymoseptoria tritici responds to heat stress by switching from its yeast-like blastospore form to hyphae or chlamydospores. The regulatory mechanisms underlying this switch are unknown. Here, we demonstrate that a differential heat stress response is ubiquitous in Z. tritici populations around the world. We used QTL mapping to identify a single locus associated with the temperature-dependent morphogenesis and we found two genes, the transcription factor ZtMsr1 and the protein phosphatase ZtYvh1, regulating this mechanism. We find that ZtMsr1 regulates repression of hyphal growth and induces chlamydospore formation whereas ZtYvh1 is required for hyphal growth. We next showed that chlamydospore formation is a response to the intracellular osmotic stress generated by the heat stress. This intracellular stress stimulates the cell wall integrity (CWI) and high-osmolarity glycerol (HOG) MAPK pathways resulting in hyphal growth. If cell wall integrity is compromised, however, ZtMsr1 represses the hyphal development program and may induce the chlamydospore-inducing genes as a stress-response survival strategy. Taken together, these results suggest a novel mechanism through which morphological transitions are orchestrated in Z. tritici - a mechanism that may also be present in other pleomorphic fungi.
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Affiliation(s)
| | - Bruce A McDonald
- Plant Pathology Group, Institute of Integrative Biology, 8092 ETH Zürich, Switzerland
| | - Javier Palma-Guerrero
- Plant Pathology Group, Institute of Integrative Biology, 8092 ETH Zürich, Switzerland.
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Blyth HR, Smith D, King R, Bayon C, Ashfield T, Walpole H, Venter E, Ray RV, Kanyuka K, Rudd JJ. Fungal plant pathogen "mutagenomics" reveals tagged and untagged mutations in Zymoseptoria tritici and identifies SSK2 as key morphogenesis and stress-responsive virulence factor. FRONTIERS IN PLANT SCIENCE 2023; 14:1140824. [PMID: 37206970 PMCID: PMC10190600 DOI: 10.3389/fpls.2023.1140824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 03/29/2023] [Indexed: 05/21/2023]
Abstract
"Mutagenomics" is the combination of random mutagenesis, phenotypic screening, and whole-genome re-sequencing to uncover all tagged and untagged mutations linked with phenotypic changes in an organism. In this study, we performed a mutagenomics screen on the wheat pathogenic fungus Zymoseptoria tritici for altered morphogenetic switching and stress sensitivity phenotypes using Agrobacterium-mediated "random" T-DNA mutagenesis (ATMT). Biological screening identified four mutants which were strongly reduced in virulence on wheat. Whole genome re-sequencing defined the positions of the T-DNA insertion events and revealed several unlinked mutations potentially affecting gene functions. Remarkably, two independent reduced virulence mutant strains, with similarly altered stress sensitivities and aberrant hyphal growth phenotypes, were found to have a distinct loss of function mutations in the ZtSSK2 MAPKKK gene. One mutant strain had a direct T-DNA insertion affecting the predicted protein's N-terminus, while the other possessed an unlinked frameshift mutation towards the C-terminus. We used genetic complementation to restore both strains' wild-type (WT) function (virulence, morphogenesis, and stress response). We demonstrated that ZtSSK2 has a non-redundant function with ZtSTE11 in virulence through the biochemical activation of the stress-activated HOG1 MAPK pathway. Moreover, we present data suggesting that SSK2 has a unique role in activating this pathway in response to specific stresses. Finally, dual RNAseq-based transcriptome profiling of WT and SSK2 mutant strains revealed many HOG1-dependent transcriptional changes in the fungus during early infection and suggested that the host response does not discriminate between WT and mutant strains during this early phase. Together these data define new genes implicated in the virulence of the pathogen and emphasise the importance of a whole genome sequencing step in mutagenomic discovery pipelines.
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Affiliation(s)
- Hannah R. Blyth
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, United Kingdom
| | - Dan Smith
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, United Kingdom
| | - Robert King
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, United Kingdom
| | - Carlos Bayon
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, United Kingdom
| | - Tom Ashfield
- Crop Health and Protection (CHAP), Rothamsted Research, Harpenden, United Kingdom
| | - Hannah Walpole
- Bioimaging Unit, Rothamsted Research, Harpenden, United Kingdom
| | - Eudri Venter
- Bioimaging Unit, Rothamsted Research, Harpenden, United Kingdom
| | - Rumiana V. Ray
- Division of Plant and Crop Sciences, School of Biosciences, University of Nottingham, Loughborough, United Kingdom
| | - Kostya Kanyuka
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, United Kingdom
| | - Jason J. Rudd
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, United Kingdom
- *Correspondence: Jason J. Rudd,
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Kilaru S, Fantozzi E, Cannon S, Schuster M, Chaloner TM, Guiu-Aragones C, Gurr SJ, Steinberg G. Zymoseptoria tritici white-collar complex integrates light, temperature and plant cues to initiate dimorphism and pathogenesis. Nat Commun 2022; 13:5625. [PMID: 36163135 PMCID: PMC9512790 DOI: 10.1038/s41467-022-33183-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 09/07/2022] [Indexed: 11/08/2022] Open
Abstract
Transitioning from spores to hyphae is pivotal to host invasion by the plant pathogenic fungus Zymoseptoria tritici. This dimorphic switch can be initiated by high temperature in vitro (~27 °C); however, such a condition may induce cellular heat stress, questioning its relevance to field infections. Here, we study the regulation of the dimorphic switch by temperature and other factors. Climate data from wheat-growing areas indicate that the pathogen sporadically experiences high temperatures such as 27 °C during summer months. However, using a fluorescent dimorphic switch reporter (FDR1) in four wild-type strains, we show that dimorphic switching already initiates at 15-18 °C, and is enhanced by wheat leaf surface compounds. Transcriptomics reveals 1261 genes that are up- or down-regulated in hyphae of all strains. These pan-strain core dimorphism genes (PCDGs) encode known effectors, dimorphism and transcription factors, and light-responsive proteins (velvet factors, opsins, putative blue light receptors). An FDR1-based genetic screen reveals a crucial role for the white-collar complex (WCC) in dimorphism and virulence, mediated by control of PCDG expression. Thus, WCC integrates light with biotic and abiotic cues to orchestrate Z. tritici infection.
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Affiliation(s)
- Sreedhar Kilaru
- Biosciences, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
| | - Elena Fantozzi
- Biosciences, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
| | - Stuart Cannon
- Biosciences, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
| | - Martin Schuster
- Biosciences, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
| | - Thomas M Chaloner
- Biosciences, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
| | | | - Sarah J Gurr
- Biosciences, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
- University of Utrecht, Padualaan 8, Utrecht, 3584 CH, The Netherlands
| | - Gero Steinberg
- Biosciences, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK.
- University of Utrecht, Padualaan 8, Utrecht, 3584 CH, The Netherlands.
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11
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Mustafa Z, Ölmez F, Akkaya M. Inactivation of a candidate effector gene of Zymoseptoria tritici affects its sporulation. Mol Biol Rep 2022; 49:11563-11571. [PMID: 36097116 DOI: 10.1007/s11033-022-07879-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 06/24/2022] [Accepted: 08/16/2022] [Indexed: 11/29/2022]
Abstract
BACKGROUND Wheat is one of the most important staple crops produced worldwide. Its susceptibility to plant diseases reduces its production significantly. One of the most important diseases of wheat is septoria tritici blotch, a devastating disease observed in fields with wet and temperate conditions. Z. tritici secretes effector proteins to influence the host's defense mechanisms, as is typical of plant pathogens. In this investigation, we evaluated the pathogenicity of some Zymoseptoria tritici effector candidate genes having a signal peptide for secretion with no known function. METHODS AND RESULTS Three genes named Mycgr3G104383, Mycgr3G104444 and Mycgr3G105826 were knocked out separately through homologous recombination, generating Z. tritici IPO323 mutants lacking the functional copy of the corresponding genes. While KO1 and KO3 mutants did not show any significant differences during phenotypic and virulence investigations, the KO2 mutant generated exclusively macropycnidiospores in artificial media, different from wild-type IPO323 which produce only micropycidiospores. The mycelial growth capability of KO2 was also severely attenuated in all of the investigated growth conditions. These changes were observed independent of growth media and growth temperatures, implying that changes were genetic and inherited through generations. Virulence of knockout mutants in wheat leaves was observed to be similar to the wild-type IPO323. CONCLUSION Understanding the biology of Z. tritici and its interactions with wheat will reveal new strategies to fight septoria tritici blotch, enabling breeding wheat cultivars resistant to a broader spectrum of Z. tritici strains. Furthermore, gene knockout via homologous recombination proved to be a powerful tool for discovering novel gene functions.
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Affiliation(s)
- Zemran Mustafa
- Department of Plant Production and Technologies, Faculty of Agricultural Science and Technologies, Sivas University of Science and Technology, Sivas, Turkey.
| | - Fatih Ölmez
- Department of Plant Protection, Faculty of Agricultural Science and Technologies, Sivas University of Science and Technology, Sivas, Turkey
| | - Mahinur Akkaya
- School of Bioengineering, Dalian University of Technology, Dalian, Liaoning, China
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12
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Two Novel Dimorphism-Related Virulence Factors of Zymoseptoria tritici Identified Using Agrobacterium-Mediated Insertional Mutagenesis. Int J Mol Sci 2021; 23:ijms23010400. [PMID: 35008825 PMCID: PMC8745584 DOI: 10.3390/ijms23010400] [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: 11/13/2021] [Revised: 12/22/2021] [Accepted: 12/24/2021] [Indexed: 11/17/2022] Open
Abstract
Diseases caused by dimorphic phytopathogenic and systemic dimorphic fungi have markedly increased in prevalence in the last decades, and understanding the morphogenic transition to the virulent state might yield novel means of controlling dimorphic fungi. The dimorphic fungus Z. tritici causes significant economic impact on wheat production, and yet the regulation of the dimorphic switch, a key first step in successful plant colonization, is still largely unexplored in this fungus. The fungus is amenable to suppression by fungicides at this switch point, and the identification of the factors controlling the dimorphic switch provides a potential source of novel targets to control Septoria tritici blotch (STB). Inhibition of the dimorphic switch can potentially prevent penetration and avoid any damage to the host plant. The aim of the current work was to unveil genetic determinants of the dimorphic transition in Z. tritici by using a forward genetics strategy. Using this approach, we unveiled two novel factors involved in the switch to the pathogenic state and used reverse genetics and complementation to confirm the role of the novel virulence factors and further gained insight into the role of these genes, using transcriptome analysis via RNA-Seq. The transcriptomes generated potentially contain key determinants of the dimorphic transition.
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13
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Zhong Z, McDonald BA, Palma-Guerrero J. Tolerance to oxidative stress is associated with both oxidative stress response and inherent growth in a fungal wheat pathogen. Genetics 2021; 217:6029569. [PMID: 33724407 DOI: 10.1093/genetics/iyaa022] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 11/23/2020] [Indexed: 01/25/2023] Open
Abstract
Reactive oxygen species are toxic byproducts of aerobic respiration that are also important in mediating a diversity of cellular functions. Reactive oxygen species form an important component of plant defenses to inhibit microbial pathogens during pathogen-plant interactions. Tolerance to oxidative stress is likely to make a significant contribution to the viability and pathogenicity of plant pathogens, but the complex network of oxidative stress responses hinders identification of the genes contributing to this trait. Here, we employed a forward genetic approach to investigate the genetic architecture of oxidative stress tolerance in the fungal wheat pathogen Zymoseptoria tritici. We used quantitative trait locus (QTL) mapping of growth and melanization under axenic conditions in two cross-populations to identify genomic regions associated with tolerance to oxidative stress. We found that QTLs associated with growth under oxidative stress as well as inherent growth can affect oxidative stress tolerance, and we identified two uncharacterized genes in a major QTL associated with this trait. Our data suggest that melanization does not affect tolerance to oxidative stress, which differs from what was found for animal pathogens. This study provides a whole-genome perspective on the genetic basis of oxidative stress tolerance in a plant pathogen.
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Affiliation(s)
- Ziming Zhong
- Plant Pathology Group, Institute of Integrative Biology, ETH Zurich, 8092 Zürich, Switzerland
| | - Bruce A McDonald
- Plant Pathology Group, Institute of Integrative Biology, ETH Zurich, 8092 Zürich, Switzerland
| | - Javier Palma-Guerrero
- Plant Pathology Group, Institute of Integrative Biology, ETH Zurich, 8092 Zürich, Switzerland.,Department of Biointeractions and Crop Protection, Rothamsted Research, AL5 2JQ Harpenden, UK
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14
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Gunasinghe N, Barbetti MJ, You MP, Dehigaspitiya P, Neate S. Dimorphism in Neopseudocercosporella capsellae, an Emerging Pathogen Causing White Leaf Spot Disease of Brassicas. Front Cell Infect Microbiol 2021; 11:678231. [PMID: 34150676 PMCID: PMC8212886 DOI: 10.3389/fcimb.2021.678231] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 04/19/2021] [Indexed: 11/13/2022] Open
Abstract
White leaf spot pathogen: Neopseudocercosporella capsellae causes significant damage to many economically important Brassicaceae crops, including oilseed rape through foliar, stem, and pod lesions under cool and wet conditions. A lack of information on critical aspects of the pathogen's life cycle limits the development of effective control measures. The presence of single-celled spores along with multi-celled conidia on cotyledons inoculated with multi-celled conidia suggested that the multi-celled conidia were able to form single-celled spores on the host surface. This study was designed to demonstrate N. capsellae morphological plasticity, which allows the shift between a yeast-like single-celled phase and the multi-celled hyphal phase. Separate experiments were designed to illustrate the pathogen's morphological transformation to single-celled yeast phase from multi-celled hyphae or multi-celled macroconidia in-vitro and in-planta. Results confirmed the ability of N. capsellae to switch between two morphologies (septate hyphae and single-celled yeast phase) on a range of artificial culture media (in-vitro) or in-planta on the host surface before infection occurs. The hyphae-to-yeast transformation occurred through the production of two morphologically distinguishable blastospore (blastoconidia) types (meso-blastospores and micro-blastospores), and arthrospores (arthroconidia).
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Affiliation(s)
- Niroshini Gunasinghe
- Centre for Crop Health, Institute for Agriculture and the Environment, Research and Innovation Division, University of Southern Queensland, Toowoomba, QLD, Australia
| | - Martin J Barbetti
- School of Agriculture and Environment and the Institute of Agriculture, Faculty of Science, The University of Western Australia, Crawley, WA, Australia
| | - Ming Pei You
- School of Agriculture and Environment and the Institute of Agriculture, Faculty of Science, The University of Western Australia, Crawley, WA, Australia
| | - Prabuddha Dehigaspitiya
- Centre for Crop Health, Institute for Agriculture and the Environment, Research and Innovation Division, University of Southern Queensland, Toowoomba, QLD, Australia
| | - Stephen Neate
- School of Agriculture, Food and Wine, Faculty of Sciences, University of Adelaide, Urrbrae, SA, Australia
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15
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Mohammadi N, Mehrabi R, Mirzadi Gohari A, Roostaei M, Mohammadi Goltapeh E, Safaie N, Kema GHJ. MADS-Box Transcription Factor ZtRlm1 Is Responsible for Virulence and Development of the Fungal Wheat Pathogen Zymoseptoria tritici. Front Microbiol 2020; 11:1976. [PMID: 33013739 PMCID: PMC7461931 DOI: 10.3389/fmicb.2020.01976] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 07/27/2020] [Indexed: 11/13/2022] Open
Abstract
Zymoseptoria tritici is one of the most economically destructive wheat diseases all over the world and is a model fungal plant pathogen within the ascomycetes. In this study, the instrumental role of the ZtRlm1 gene encoding a MADS-box transcription factor (TF) in the infection process of Z. tritici was functionally characterized as these proteins play critical roles in the global gene regulation required for various developmental and physiological processes. Our infection assays showed that ZtRlm1 mutants were attenuated in disease development as a 30 and 90% reduction in chloro-necrotic lesions and pycnidia formation, respectively, were observed in plants inoculated with ZtRlm1 mutant strains demonstrating that ZtRlm1 is a crucial factor playing a significant role in the late stage of infection corresponding with pycnidial formation. Our expression analysis demonstrated that the transcript level of ZtRlm1 is induced at 2 and 20 days post-inoculation, coinciding with pycnidial sporulation. In addition, microscopic analyses showed that branch intensity and biomass production were significantly reduced, indicating that impaired pycnidia formation is a result of impaired differentiation and biomass production in the ZtRlm1 mutants. Furthermore, melanization, a phenomenon required for fruiting body formation, was significantly hampered in ZtRlm1 mutants as they were not melanized under all tested temperature and media conditions. Overall, our data showed that impaired disease development of the ZtRlm1 mutants is mainly due to the significant impact of ZtRlm1 in different cellular processes, including differentiation, branching, fungal biomass production, and melanization, in which identification of downstream genes are of interest to increase our understanding of this pathosystem.
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Affiliation(s)
- Naser Mohammadi
- Dryland Agricultural Research Institute, Agricultural Research, Education and Extension Organization (ARREO), Maragheh, Iran
| | - Rahim Mehrabi
- Department of Biotechnology, College of Agriculture, Isfahan University of Technology, Isfahan, Iran
| | - Amir Mirzadi Gohari
- Department of Plant Pathology, Faculty of Agricultural Sciences and Engineering, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran
| | - Mozaffar Roostaei
- Dryland Agricultural Research Institute, Agricultural Research, Education and Extension Organization (ARREO), Maragheh, Iran
| | | | - Naser Safaie
- Department of Plant Pathology, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran
| | - Gert H J Kema
- Wageningen University and Research, Wageningen Plant Research, Wageningen, Netherlands
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16
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Ide-Pérez MR, Fernández-López MG, Sánchez-Reyes A, Leija A, Batista-García RA, Folch-Mallol JL, Sánchez-Carbente MDR. Aromatic Hydrocarbon Removal by Novel Extremotolerant Exophiala and Rhodotorula Spp. from an Oil Polluted Site in Mexico. J Fungi (Basel) 2020; 6:E135. [PMID: 32823980 PMCID: PMC7559356 DOI: 10.3390/jof6030135] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 08/11/2020] [Accepted: 08/12/2020] [Indexed: 02/06/2023] Open
Abstract
Since Aromatic hydrocarbons are recalcitrant and toxic, strategies to remove them are needed. The aim of this work was to isolate fungi capable of using aromatic hydrocarbons as carbon sources. Two isolates from an oil polluted site in Mexico were identified through morphological and molecular markers as a novel Rhodotorula sp. and an Exophiala sp. Both strains were able to grow in a wide range of pH media, from 4 to 12, showing their optimal growth at alkaline pH's and are both halotolerant. The Exophiala strain switched from hyphae to yeast morphotype in high salinity conditions. To the best of our knowledge, this is the first report of salt triggering dimorphism. The Rhodotorula strain, which is likely a new undescribed species, was capable of removing singled ringed aromatic compounds such as benzene, xylene, and toluene, but could not remove benzo[a] pyrene nor phenanthrene. Nevertheless, these hydrocarbons did not impair its growth. The Exophiala strain showed a different removal capacity. It could remove the polyaromatic hydrocarbons but performed poorly at removing toluene and xylene. Nevertheless, it still could grow well in the presence of the aromatic compounds. These strains could have a potential for aromatic compounds removal.
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Affiliation(s)
- Martín R. Ide-Pérez
- Centro de Investigación en Biotecnología, Universidad Autónoma del Estado de Morelos, Cuernavaca 62209, Mexico;
| | - Maikel Gilberto Fernández-López
- Centro de Investigación en Dinámica Celular-Instituto de Investigaciones Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca 62209, Mexico; (M.G.F.-L.); (R.A.B.-G.)
| | - Ayixon Sánchez-Reyes
- Cátedras Conacyt-Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca 62209, Mexico;
| | - Alfonso Leija
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca 62209, Mexico;
| | - Ramón Alberto Batista-García
- Centro de Investigación en Dinámica Celular-Instituto de Investigaciones Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca 62209, Mexico; (M.G.F.-L.); (R.A.B.-G.)
| | - Jorge Luis Folch-Mallol
- Centro de Investigación en Biotecnología, Universidad Autónoma del Estado de Morelos, Cuernavaca 62209, Mexico;
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17
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Francisco CS, Zwyssig MM, Palma-Guerrero J. The role of vegetative cell fusions in the development and asexual reproduction of the wheat fungal pathogen Zymoseptoria tritici. BMC Biol 2020; 18:99. [PMID: 32782023 PMCID: PMC7477884 DOI: 10.1186/s12915-020-00838-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Accepted: 07/27/2020] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND The ability of fungal cells to undergo cell-to-cell communication and anastomosis, the process of vegetative hyphal fusion, allows them to maximize their overall fitness. Previous studies in a number of fungal species have identified the requirement of several signaling pathways for anastomosis, including the so far best characterized soft (So) gene, and the MAPK pathway components MAK-1 and MAK-2 of Neurospora crassa. Despite the observations of hyphal fusions' involvement in pathogenicity and host adhesion, the connection between cell fusion and fungal lifestyles is still unclear. Here, we address the role of anastomosis in fungal development and asexual reproduction in Zymoseptoria tritici, the most important fungal pathogen of wheat in Europe. RESULTS We show that Z. tritici undergoes self-fusion between distinct cellular structures, and its mechanism is dependent on the initial cell density. Contrary to other fungi, cell fusion in Z. tritici only resulted in cytoplasmic mixing but not in multinucleated cell formation. The deletion of the So orthologous ZtSof1 disrupted cell-to-cell communication affecting both hyphal and germling fusion. We show that Z. tritici mutants for MAPK-encoding ZtSlt2 (orthologous to MAK-1) and ZtFus3 (orthologous to MAK-2) genes also failed to undergo anastomosis, demonstrating the functional conservation of this signaling mechanism across species. Additionally, the ΔZtSof1 mutant was severely impaired in melanization, suggesting that the So gene function is related to melanization. Finally, we demonstrated that anastomosis is dispensable for pathogenicity, but essential for the pycnidium development, and its absence abolishes the asexual reproduction of Z. tritici. CONCLUSIONS We demonstrate the role for ZtSof1, ZtSlt2, and ZtFus3 in cell fusions of Z. tritici. Cell fusions are essential for different aspects of the Z. tritici biology, and the ZtSof1 gene is a potential target to control septoria tritici blotch (STB) disease.
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Affiliation(s)
| | - Maria Manuela Zwyssig
- Plant Pathology Group, Institute of Integrative Biology, ETH Zürich, 8092, Zürich, Switzerland
| | - Javier Palma-Guerrero
- Plant Pathology Group, Institute of Integrative Biology, ETH Zürich, 8092, Zürich, Switzerland.
- New Address: Department of Biointeractions and Crop Protection, Rothamsted Research, Harpenden, UK.
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18
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McCorison CB, Goodwin SB. The wheat pathogen Zymoseptoria tritici senses and responds to different wavelengths of light. BMC Genomics 2020; 21:513. [PMID: 32711450 PMCID: PMC7382159 DOI: 10.1186/s12864-020-06899-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 07/08/2020] [Indexed: 12/30/2022] Open
Abstract
Background The ascomycete fungus Zymoseptoria tritici (synonyms: Mycosphaerella graminicola, Septoria tritici) is a major pathogen of wheat that causes the economically important foliar disease Septoria tritici blotch. Despite its importance as a pathogen, little is known about the reaction of this fungus to light. To test for light responses, cultures of Z. tritici were grown in vitro for 16-h days under white, blue or red light, and their transcriptomes were compared with each other and to those obtained from control cultures grown in darkness. Results There were major differences in gene expression with over 3400 genes upregulated in one or more of the light conditions compared to dark, and from 1909 to 2573 genes specifically upregulated in the dark compared to the individual light treatments. Differences between light treatments were lower, ranging from only 79 differentially expressed genes in the red versus blue comparison to 585 between white light and red. Many of the differentially expressed genes had no functional annotations. For those that did, analysis of the Gene Ontology (GO) terms showed that those related to metabolism were enriched in all three light treatments, while those related to growth and communication were more prevalent in the dark. Interestingly, genes for effectors that have been shown previously to be involved in pathogenicity also were upregulated in one or more of the light treatments, suggesting a possible role of light for infection. Conclusions This analysis shows that Z. tritici can sense and respond to light with a huge effect on transcript abundance. High proportions of differentially expressed genes with no functional annotations illuminates the huge gap in our understanding of light responses in this fungus. Differential expression of genes for effectors indicates that light could be important for pathogenicity; unknown effectors may show a similar pattern of transcription. A better understanding of the effects of light on pathogenicity and other biological processes of Z. tritici could help to manage Septoria tritici blotch in the future.
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Affiliation(s)
- Cassandra B McCorison
- Department of Botany and Plant Pathology, Purdue University, 915 West State Street, West Lafayette, IN, 47907-2054, USA
| | - Stephen B Goodwin
- USDA-Agricultural Research Service, Crop Production and Pest Control Research Unit, Department of Botany and Plant Pathology, Purdue University, 915 West State Street, West Lafayette, IN, 47907-2054, USA.
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19
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Yang Q, Song L, Miao Z, Su M, Liang W, He Y. Acetylation of BcHpt Lysine 161 Regulates Botrytis cinerea Sensitivity to Fungicides, Multistress Adaptation and Virulence. Front Microbiol 2020; 10:2965. [PMID: 31969871 PMCID: PMC6960119 DOI: 10.3389/fmicb.2019.02965] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 12/09/2019] [Indexed: 12/02/2022] Open
Abstract
BcHpt is a core element of the high-osmolarity glycerol (HOG) transduction pathway in Botrytis cinerea. In contrast to other elements of the pathway, which have been characterized and proven to play important roles in vegetative differentiation, fungicide resistance, the multistress response, and virulence in B. cinerea, BcHpt (Histidine-containing phosphotransfer) is essential but uncharacterized in B. cinerea. Our previous study reported the first lysine acetylation site (Lys161) in BcHpt. In this study, the functions of this lysine acetylation site in BcHpt were characterized using site-directed mutagenesis. To mimic Lys161 acetylation, we generated the mutant strain ΔBcHPt + BcHptK161Q-GFP, which exhibited a slower growth rate; lower pathogenicity; higher sensitivity to multiple stresses, including osmotic and oxidative stresses, dicarboximides, and demethylation inhibitors (DMIs); and lower BcSak1 phosphorylation levels than wild-type B. cinerea. Constitutive acetylation of BcHpt Ly161 apparently inhibits hyphal growth, the multistress response, and sensitivity to fungicides in B. cinerea. Moreover, the lysine acetylation site affected phosphorylation of the MAPK BcSak1.
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Affiliation(s)
- Qianqian Yang
- Key Lab of Integrated Crop Pest Management of Shandong, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, China
| | - Limin Song
- Key Lab of Integrated Crop Pest Management of Shandong, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, China
| | - Zhengang Miao
- Key Lab of Integrated Crop Pest Management of Shandong, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, China
| | - Meiling Su
- Key Lab of Integrated Crop Pest Management of Shandong, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, China
| | - Wenxing Liang
- Key Lab of Integrated Crop Pest Management of Shandong, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, China.,Shandong Province Key Laboratory of Applied Mycology, Qingdao Agricultural University, Qingdao, China
| | - Yawen He
- State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
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Habig M, Bahena‐Garrido SM, Barkmann F, Haueisen J, Stukenbrock EH. The transcription factor Zt107320 affects the dimorphic switch, growth and virulence of the fungal wheat pathogen Zymoseptoria tritici. MOLECULAR PLANT PATHOLOGY 2020; 21:124-138. [PMID: 31702117 PMCID: PMC6913241 DOI: 10.1111/mpp.12886] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Zymoseptoria tritici is a filamentous fungus causing Septoria tritici blotch in wheat. The pathogen has a narrow host range and infections of grasses other than susceptible wheat are blocked early after stomatal penetration. During these abortive infections, the fungus shows a markedly different gene expression pattern. However, the underlying mechanisms causing differential gene expression during host and non-host interactions are largely unknown, but likely include transcriptional regulators responsible for the onset of an infection programme in compatible hosts. MoCOD1, a member of the fungal Zn(II)2 Cys6 transcription factor family, has been shown to directly affect pathogenicity in the rice blast pathogen Magnaporthe oryzae. Here, we analyse the role of the putative transcription factor Zt107320, a homologue of MoCOD1, during infection of compatible and incompatible hosts by Z. tritici. We show for the first time that Zt107320 is differentially expressed in host versus non-host infections and that lower expression corresponds to an incompatible infection of non-hosts. Applying reverse genetics approaches, we further show that Zt107320 regulates the dimorphic switch as well as the growth rate of Z. tritici and affects fungal cell wall composition in vitro. Moreover, ∆Zt107320 mutants showed reduced virulence during compatible infections of wheat. We conclude that Zt107320 directly influences pathogen fitness and propose that Zt107320 is involved in the regulation of growth processes and pathogenicity during infection.
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Affiliation(s)
- Michael Habig
- Environmental GenomicsChristian‐Albrechts University of KielKielGermany
- Max Planck Institute for Evolutionary BiologyPlönGermany
| | - Sharon Marie Bahena‐Garrido
- Environmental GenomicsChristian‐Albrechts University of KielKielGermany
- Max Planck Institute for Evolutionary BiologyPlönGermany
- Present address:
National Research Institute of Brewing3‐7‐1 KagamiyamaHigashi‐Hiroshima739‐0046Japan
| | - Friederike Barkmann
- Environmental GenomicsChristian‐Albrechts University of KielKielGermany
- Max Planck Institute for Evolutionary BiologyPlönGermany
| | - Janine Haueisen
- Environmental GenomicsChristian‐Albrechts University of KielKielGermany
- Max Planck Institute for Evolutionary BiologyPlönGermany
| | - Eva Holtgrewe Stukenbrock
- Environmental GenomicsChristian‐Albrechts University of KielKielGermany
- Max Planck Institute for Evolutionary BiologyPlönGermany
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Li Y, He P, Tian C, Wang Y. CgHog1 controls the adaptation to both sorbitol and fludioxonil in Colletotrichum gloeosporioides. Fungal Genet Biol 2019; 135:103289. [PMID: 31704368 DOI: 10.1016/j.fgb.2019.103289] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 10/29/2019] [Accepted: 10/30/2019] [Indexed: 01/22/2023]
Abstract
The HOG (high-osmolarity glycerol) pathway is critical for the appropriate adaptation to adverse conditions. Here, we demonstrated that the deletion of CgHog1 resulted in enhanced sensitivity to osmotic stress and increased resistance to fludioxonil in the poplar anthracnose fungus Colletotrichum gloeosporioides. The accumulation of chitin around hyphal tips was obviously decreased in the ΔCgHog1 strain under sorbitol, whereas it strongly was increased in the response to fludioxonil compared with the wild type. To investigate the underlying mechanism of CgHog1-mediated adaption to osmotic stress and fludioxonil, transcriptomic profiles were performed in both the ΔCgHog1 strain and the wild type under the treatment of sorbitol and fludioxonil, respectively. Under sorbitol, genes associated with glycolysis, lipid metabolism, and accumulation of soluble sugars and amino acids were differentially expressed; under fludioxonil, vesicle trafficking-related genes were highly downregulated in the ΔCgHog1 strain, which was consistent with abnormal vacuoles distribution and morphology of hyphae, indicating that the growth defect caused by fludioxonil may be associated with disruption of endocytosis. Taken together, we elucidated the adaptation mechanisms of how CgHog1 regulates appropriate response to sorbitol and fludioxonil via different metabolism pathways. These findings extend our insights into the HOG pathway in fungi.
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Affiliation(s)
- Yangfan Li
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing, China
| | - Puhuizhong He
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing, China
| | - Chengming Tian
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing, China
| | - Yonglin Wang
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing, China.
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Two Verticillium dahliae MAPKKKs, VdSsk2 and VdSte11, Have Distinct Roles in Pathogenicity, Microsclerotial Formation, and Stress Adaptation. mSphere 2019; 4:4/4/e00426-19. [PMID: 31292234 PMCID: PMC6620378 DOI: 10.1128/msphere.00426-19] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
These data provide insights into the distinctive functions of VdSsk2 and VdSte11 in pathogenicity, stress adaptation, and microsclerotial formation in V. dahliae. Verticillium dahliae causes destructive vascular wilt diseases on more than 200 plant species, including economically important crops and ornamental trees worldwide. The melanized microsclerotia enable the fungus to survive for years in soil and are crucial for its disease cycle. Previously, we found that the VdPbs2-VdHog1 (V. dahliae Pbs2-V. dahliae Hog1) module plays key roles in microsclerotial formation, stress responses, and virulence in V. dahliae. In this study, two mitogen-activated protein kinase kinase kinases (MAPKKKs) homologous to Ssk2p and Ste11p, which activate the Pbs2p-Hog1p module by phosphorylation in budding yeast, were identified in the genome of V. dahliae. Both ΔVdSsk2 (V. dahliaeSsk2) and ΔVdSte11 strains showed severe defects in microsclerotial formation and melanin biosynthesis, but the relative importance of these two genes in microsclerotial development was different. Deletion of VdSsk2, but not VdSte11, affected responses to osmotic stress, fungicidal response, and cell wall stressors. The ΔVdSsk2 strain exhibited a significant reduction in virulence, while the ΔVdSte11 strain was nonpathogenic due to failure to penetrate and form hyphopodia. Phosphorylation assays demonstrated that VdSsk2, but not VdSte11, can phosphorylate VdHog1 in V. dahliae. Moreover, VdCrz1, encoding a calcineurin-responsive zinc finger transcription factor and a key regulator of calcium signaling in fungi, was misregulated in the ΔVdSsk2, ΔVdPbs2, and ΔVdHog1 mutants. IMPORTANCE These data provide insights into the distinctive functions of VdSsk2 and VdSte11 in pathogenicity, stress adaptation, and microsclerotial formation in V. dahliae.
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23
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Francisco CS, Ma X, Zwyssig MM, McDonald BA, Palma-Guerrero J. Morphological changes in response to environmental stresses in the fungal plant pathogen Zymoseptoria tritici. Sci Rep 2019; 9:9642. [PMID: 31270361 PMCID: PMC6610121 DOI: 10.1038/s41598-019-45994-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Accepted: 06/20/2019] [Indexed: 01/15/2023] Open
Abstract
During their life cycles, pathogens have to adapt to many biotic and abiotic environmental stresses to maximize their overall fitness. Morphological transitions are one of the least understood of the many strategies employed by fungal plant pathogens to adapt to constantly changing environments, even though different morphotypes may play important biological roles. Here, we first show that blastospores (the "yeast-like" form of the pathogen typically known only under laboratory conditions) can form from germinated pycnidiospores (asexual spores) on the surface of wheat leaves, suggesting that this morphotype can play an important role in the natural history of Z. tritici. Next, we characterized the morphological responses of this fungus to a series of environmental stresses to understand the effects of changing environments on fungal morphology and adaptation. All tested stresses induced morphological changes, but different responses were found among four strains. We discovered that Z. tritici forms chlamydospores and demonstrated that these structures are better able to survive extreme cold, heat and drought than other cell types. Finally, a transcriptomic analysis showed that morphogenesis and the expression of virulence factors are co-regulated in this pathogen. Our findings illustrate how changing environmental conditions can affect cellular morphology and lead to the formation of new morphotypes, with each morphotype having a potential impact on both pathogen survival and disease epidemiology.
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Affiliation(s)
| | - Xin Ma
- Plant Pathology Group, Institute of Integrative Biology, ETH Zürich, 8092, Zürich, Switzerland
| | - Maria Manuela Zwyssig
- Plant Pathology Group, Institute of Integrative Biology, ETH Zürich, 8092, Zürich, Switzerland
| | - Bruce A McDonald
- Plant Pathology Group, Institute of Integrative Biology, ETH Zürich, 8092, Zürich, Switzerland
| | - Javier Palma-Guerrero
- Plant Pathology Group, Institute of Integrative Biology, ETH Zürich, 8092, Zürich, Switzerland.
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24
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Derbyshire MC, Gohari AM, Mehrabi R, Kilaru S, Steinberg G, Ali S, Bailey A, Hammond-Kosack K, Kema GHJ, Rudd JJ. Phosphopantetheinyl transferase (Ppt)-mediated biosynthesis of lysine, but not siderophores or DHN melanin, is required for virulence of Zymoseptoria tritici on wheat. Sci Rep 2018; 8:17069. [PMID: 30459352 PMCID: PMC6244202 DOI: 10.1038/s41598-018-35223-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 10/30/2018] [Indexed: 12/19/2022] Open
Abstract
Zymoseptoria tritici is the causal agent of Septoria tritici blotch (STB) disease of wheat. Z. tritici is an apoplastic fungal pathogen, which does not penetrate plant cells at any stage of infection, and has a long initial period of symptomless leaf colonisation. During this phase it is unclear to what extent the fungus can access host plant nutrients or communicate with plant cells. Several important primary and secondary metabolite pathways in fungi are regulated by the post-translational activator phosphopantetheinyl transferase (Ppt) which provides an essential co-factor for lysine biosynthesis and the activities of non-ribosomal peptide synthases (NRPS) and polyketide synthases (PKS). To investigate the relative importance of lysine biosynthesis, NRPS-based siderophore production and PKS-based DHN melanin biosynthesis, we generated deletion mutants of ZtPpt. The ∆ZtPpt strains were auxotrophic for lysine and iron, non-melanised and non-pathogenic on wheat. Deletion of the three target genes likely affected by ZtPpt loss of function (Aar- lysine; Nrps1-siderophore and Pks1- melanin), highlighted that lysine auxotrophy was the main contributing factor for loss of virulence, with no reduction caused by loss of siderophore production or melanisation. This reveals Ppt, and the lysine biosynthesis pathway, as potential targets for fungicides effective against Z. tritici.
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Affiliation(s)
- Mark C Derbyshire
- BioIntercations and Crop Protection, Rothamsted Research, Harpenden, Hertfordshire, UK.,Centre for Crop and Disease Management, Curtin University, Perth, Australia
| | - Amir Mirzadi Gohari
- Department of Plant Pathology, Faculty of Agricultural Sciences and Engineering, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.,Wageningen University and Research, Wageningen Plant Research, PO Box 16, 6700AA, Wageningen, The Netherlands
| | - Rahim Mehrabi
- Department of Biotechnology, College of Agriculture, Isfahan University of Technology, Isfahan, 84156-83111, Iran
| | | | | | - Solaf Ali
- Technical College of Health, Sulaimani Polytechnic University, Qrga, Wrme Street, Mardin 327, Alley 76, Sulaimaniyah, Kurdistan Region of Iraq, Sulaimani Governorate, Iraq
| | - Andy Bailey
- School of Biological Sciences, Bristol University, 24 Tyndall Avenue, Bristol, UK
| | - Kim Hammond-Kosack
- BioIntercations and Crop Protection, Rothamsted Research, Harpenden, Hertfordshire, UK
| | - Gert H J Kema
- Wageningen University and Research, Wageningen Plant Research, PO Box 16, 6700AA, Wageningen, The Netherlands. .,Wageningen University and Research, Laboratory of Phytopathology, PO box 16, 6700AA, Wageningen, The Netherlands.
| | - Jason J Rudd
- BioIntercations and Crop Protection, Rothamsted Research, Harpenden, Hertfordshire, UK.
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25
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Li S, Musungu B, Lightfoot D, Ji P. The Interactomic Analysis Reveals Pathogenic Protein Networks in Phomopsis longicolla Underlying Seed Decay of Soybean. Front Genet 2018; 9:104. [PMID: 29666630 PMCID: PMC5891612 DOI: 10.3389/fgene.2018.00104] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 03/15/2018] [Indexed: 12/31/2022] Open
Abstract
Phomopsis longicolla T. W. Hobbs (syn. Diaporthe longicolla) is the primary cause of Phomopsis seed decay (PSD) in soybean, Glycine max (L.) Merrill. This disease results in poor seed quality and is one of the most economically important seed diseases in soybean. The objectives of this study were to infer protein-protein interactions (PPI) and to identify conserved global networks and pathogenicity subnetworks in P. longicolla including orthologous pathways for cell signaling and pathogenesis. The interlog method used in the study identified 215,255 unique PPIs among 3,868 proteins. There were 1,414 pathogenicity related genes in P. longicolla identified using the pathogen host interaction (PHI) database. Additionally, 149 plant cell wall degrading enzymes (PCWDE) were detected. The network captured five different classes of carbohydrate degrading enzymes, including the auxiliary activities, carbohydrate esterases, glycoside hydrolases, glycosyl transferases, and carbohydrate binding molecules. From the PPI analysis, novel interacting partners were determined for each of the PCWDE classes. The most predominant class of PCWDE was a group of 60 glycoside hydrolases proteins. The glycoside hydrolase subnetwork was found to be interacting with 1,442 proteins within the network and was among the largest clusters. The orthologous proteins FUS3, HOG, CYP1, SGE1, and the g5566t.1 gene identified in this study could play an important role in pathogenicity. Therefore, the P. longicolla protein interactome (PiPhom) generated in this study can lead to a better understanding of PPIs in soybean pathogens. Furthermore, the PPI may aid in targeting of genes and proteins for further studies of the pathogenicity mechanisms.
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Affiliation(s)
- Shuxian Li
- Crop Genetics Research Unit, United States Department of Agriculture, Agricultural Research Service, Stoneville, MS, United States
| | - Bryan Musungu
- Department of Plant Biology, Southern Illinois University, Carbondale, IL, United States
| | - David Lightfoot
- Department of Plant, Soil, and Agricultural Systems, Southern Illinois University, Carbondale, IL, United States
| | - Pingsheng Ji
- Department of Plant Pathology, University of Georgia, Tifton, GA, United States
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26
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Jiang L, Situ J, Deng YZ, Wan L, Xu D, Chen Y, Xi P, Jiang Z. PlMAPK10, a Mitogen-Activated Protein Kinase (MAPK) in Peronophythora litchii, Is Required for Mycelial Growth, Sporulation, Laccase Activity, and Plant Infection. Front Microbiol 2018; 9:426. [PMID: 29568294 PMCID: PMC5852060 DOI: 10.3389/fmicb.2018.00426] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Accepted: 02/22/2018] [Indexed: 01/10/2023] Open
Abstract
Mitogen-activated protein kinase (MAPK) pathways are ubiquitous and evolutionarily conserved signal transduction modules directing cellular respond to a diverse array of stimuli, in the eukaryotic organisms. In this study, PlMAPK10 was identified to encode a MAPK in Peronophythora litchii, the oomycete pathogen causing litchi downy blight disease. PlMAPK10, containing a specific and highly conserved dual phosphorylation lip sequence SEY (Serine-Glutamic-Tyrosine), represents a novel group of MAPKs as previously reported. Transcriptional profiling showed that PlMAPK10 expression was up-regulated in zoospore and cyst stages. To elucidate its function, the PlMAPK10 gene was silenced by stable transformation. PlMAPK10 silence did not impair oospore production, sporangium germination, zoospore encyst, or cyst germination but hindered hyphal growth, sporulation, pathogenicity, likely due to altering laccase activity. Over all, our results indicated that a MAPK encoded by PlMAPK10 gene in P. litchii is important for pathogenic development.
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Affiliation(s)
- Liqun Jiang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China.,Guangdong Province Key Laboratory of New Technology in Rice Breeding, Rice Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Junjian Situ
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China
| | - Yi Zhen Deng
- Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| | - Lang Wan
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China
| | - Dandan Xu
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China
| | - Yubin Chen
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China
| | - Pinggen Xi
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China
| | - Zide Jiang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China
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27
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Kema GHJ, Mirzadi Gohari A, Aouini L, Gibriel HAY, Ware SB, van den Bosch F, Manning-Smith R, Alonso-Chavez V, Helps J, Ben M'Barek S, Mehrabi R, Diaz-Trujillo C, Zamani E, Schouten HJ, van der Lee TAJ, Waalwijk C, de Waard MA, de Wit PJGM, Verstappen ECP, Thomma BPHJ, Meijer HJG, Seidl MF. Stress and sexual reproduction affect the dynamics of the wheat pathogen effector AvrStb6 and strobilurin resistance. Nat Genet 2018; 50:375-380. [PMID: 29434356 DOI: 10.1038/s41588-018-0052-9] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 01/06/2018] [Indexed: 11/09/2022]
Abstract
Host resistance and fungicide treatments are cornerstones of plant-disease control. Here, we show that these treatments allow sex and modulate parenthood in the fungal wheat pathogen Zymoseptoria tritici. We demonstrate that the Z. tritici-wheat interaction complies with the gene-for-gene model by identifying the effector AvrStb6, which is recognized by the wheat resistance protein Stb6. Recognition triggers host resistance, thus implying removal of avirulent strains from pathogen populations. However, Z. tritici crosses on wheat show that sex occurs even with an avirulent parent, and avirulence alleles are thereby retained in subsequent populations. Crossing fungicide-sensitive and fungicide-resistant isolates under fungicide pressure results in a rapid increase in resistance-allele frequency. Isolates under selection always act as male donors, and thus disease control modulates parenthood. Modeling these observations for agricultural and natural environments reveals extended durability of host resistance and rapid emergence of fungicide resistance. Therefore, fungal sex has major implications for disease control.
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Affiliation(s)
- Gerrit H J Kema
- Wageningen Plant Research, Wageningen University and Research, Wageningen, the Netherlands. .,Laboratory of Phytopathology, Wageningen University and Research, Wageningen, the Netherlands.
| | - Amir Mirzadi Gohari
- Wageningen Plant Research, Wageningen University and Research, Wageningen, the Netherlands.,Department of Plant Protection, College of Agriculture, University of Tehran, Karaj, Iran
| | - Lamia Aouini
- Wageningen Plant Research, Wageningen University and Research, Wageningen, the Netherlands
| | - Hesham A Y Gibriel
- Laboratory of Phytopathology, Wageningen University and Research, Wageningen, the Netherlands
| | - Sarah B Ware
- Wageningen Plant Research, Wageningen University and Research, Wageningen, the Netherlands.,Department of Biological Sciences, Benedictine University, Lisle, IL, USA
| | | | | | | | | | - Sarrah Ben M'Barek
- Laboratory of Molecular Plant Physiology, Biotechnology Center of Borj Cedria (CBBC), Hammam-Lif, Tunisia
| | - Rahim Mehrabi
- Department of Agricultural Biotechnology, College of Agriculture, Isfahan University of Technology, Isfahan, Iran
| | - Caucasella Diaz-Trujillo
- Wageningen Plant Research, Wageningen University and Research, Wageningen, the Netherlands.,Laboratory of Phytopathology, Wageningen University and Research, Wageningen, the Netherlands
| | - Elham Zamani
- Department of Plant Pathology, Tarbiat Modares University, Tehran, Iran
| | - Henk J Schouten
- Wageningen Plant Research, Wageningen University and Research, Wageningen, the Netherlands
| | - Theo A J van der Lee
- Wageningen Plant Research, Wageningen University and Research, Wageningen, the Netherlands
| | - Cees Waalwijk
- Wageningen Plant Research, Wageningen University and Research, Wageningen, the Netherlands
| | - Maarten A de Waard
- Laboratory of Phytopathology, Wageningen University and Research, Wageningen, the Netherlands
| | - Pierre J G M de Wit
- Laboratory of Phytopathology, Wageningen University and Research, Wageningen, the Netherlands
| | - Els C P Verstappen
- Wageningen Plant Research, Wageningen University and Research, Wageningen, the Netherlands
| | - Bart P H J Thomma
- Laboratory of Phytopathology, Wageningen University and Research, Wageningen, the Netherlands
| | - Harold J G Meijer
- Wageningen Plant Research, Wageningen University and Research, Wageningen, the Netherlands
| | - Michael F Seidl
- Laboratory of Phytopathology, Wageningen University and Research, Wageningen, the Netherlands
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28
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Stewart EL, Croll D, Lendenmann MH, Sanchez‐Vallet A, Hartmann FE, Palma‐Guerrero J, Ma X, McDonald BA. Quantitative trait locus mapping reveals complex genetic architecture of quantitative virulence in the wheat pathogen Zymoseptoria tritici. MOLECULAR PLANT PATHOLOGY 2018; 19:201-216. [PMID: 27868326 PMCID: PMC6638037 DOI: 10.1111/mpp.12515] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We conducted a comprehensive analysis of virulence in the fungal wheat pathogen Zymoseptoria tritici using quantitative trait locus (QTL) mapping. High-throughput phenotyping based on automated image analysis allowed the measurement of pathogen virulence on a scale and with a precision that was not previously possible. Across two mapping populations encompassing more than 520 progeny, 540 710 pycnidia were counted and their sizes and grey values were measured. A significant correlation was found between pycnidia size and both spore size and number. Precise measurements of percentage leaf area covered by lesions provided a quantitative measure of host damage. Combining these large and accurate phenotypic datasets with a dense panel of restriction site-associated DNA sequencing (RADseq) genetic markers enabled us to genetically dissect pathogen virulence into components related to host damage and those related to pathogen reproduction. We showed that different components of virulence can be under separate genetic control. Large- and small-effect QTLs were identified for all traits, with some QTLs specific to mapping populations, cultivars and traits and other QTLs shared among traits within the same mapping population. We associated the presence of four accessory chromosomes with small, but significant, increases in several virulence traits, providing the first evidence for a meaningful function associated with accessory chromosomes in this organism. A large-effect QTL involved in host specialization was identified on chromosome 7, leading to the identification of candidate genes having a large effect on virulence.
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Affiliation(s)
- Ethan l. Stewart
- Plant Pathology Group, ETH Zürich, Universitätstrasse 2Zürich8092Switzerland
| | - Daniel Croll
- Plant Pathology Group, ETH Zürich, Universitätstrasse 2Zürich8092Switzerland
| | - Mark H. Lendenmann
- Plant Pathology Group, ETH Zürich, Universitätstrasse 2Zürich8092Switzerland
| | | | - Fanny E. Hartmann
- Plant Pathology Group, ETH Zürich, Universitätstrasse 2Zürich8092Switzerland
| | | | - Xin Ma
- Plant Pathology Group, ETH Zürich, Universitätstrasse 2Zürich8092Switzerland
| | - Bruce A. McDonald
- Plant Pathology Group, ETH Zürich, Universitätstrasse 2Zürich8092Switzerland
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29
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Mohammadi N, Mehrabi R, Mirzadi Gohari A, Mohammadi Goltapeh E, Safaie N, Kema GHJ. The ZtVf1 transcription factor regulates development and virulence in the foliar wheat pathogen Zymoseptoria tritici. Fungal Genet Biol 2017; 109:26-35. [PMID: 29031630 DOI: 10.1016/j.fgb.2017.10.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 10/03/2017] [Accepted: 10/11/2017] [Indexed: 10/18/2022]
Abstract
The dimorphic fungal pathogen, Zymoseptoria tritici undergoes discrete developmental changes to complete its life cycle on wheat. Molecular mechanisms underlying morphogenesis during infection process of Z. tritici are poorly understood. In this study, we have investigated the role of ZtVf1 gene encoding a transcription factor belonging to C2-H2 subfamily. In planta assays revealed that ZtVf1 is required for virulence. Reduced necrotic lesions and low pycnidia density within the lesions resulted in significantly reduced virulence of ZtVf1 mutants. Cytological analysis showed that the impaired virulence of ZtVf1 mutants attributed to reduced penetration and colonization along with hampered pycnidia differentiation. In vitro phenotyping showed that ZtVf1 deletion affects hyphal branching and biomass production suggesting that the reduced tissue colonization by the ZtVf1 mutant might be due to lower hyphal branching and less fungal biomass production. In addition, the majority of infected substomatal cavities by the ZtVf1 mutant filled with compacted mycelia mat that did not differentiate to mature pycnidia indicating that the impaired melanization negatively affected pycnidia formation and maturation. The ZtVf1 might target multiple genes belonging to different cellular processes whose identification is of eminent interest to increase our understanding of this pathosystem. Overall, the data provided in this study indicates that attenuated pathogenicity of ZtVf1 mutant is due to involvement of this gene in the regulation of both early and late stages of infection.
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Affiliation(s)
- Naser Mohammadi
- Department of Plant Pathology, Faculty of Agriculture, Tarbiat Modares University, P.O. Box 14115-111, Tehran, Iran; Dryland Agricultural Research Institute, Agricultural Research, Education & Extension Organization (ARREO), Maragheh, Iran
| | - Rahim Mehrabi
- Seed & Plant Improvement Institute, Agricultural Research, Education & Extension Organization (ARREO), P.O. Box 31585-4119, Karaj, Iran; Department of Biotechnology, College of Agriculture, Isfahan University of Technology, Isfahan, Iran.
| | - Amir Mirzadi Gohari
- Department of Plant Pathology, Faculty of Agricultural Sciences and Engineering, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran
| | - Ebrahim Mohammadi Goltapeh
- Department of Plant Pathology, Faculty of Agriculture, Tarbiat Modares University, P.O. Box 14115-111, Tehran, Iran
| | - Naser Safaie
- Department of Plant Pathology, Faculty of Agriculture, Tarbiat Modares University, P.O. Box 14115-111, Tehran, Iran
| | - Gert H J Kema
- Laboratory of Phytopathology, Wageningen University and Research, 6700AA Wageningen, The Netherlands; Wageningen University and Research, Wageningen Plant Research, P.O. Box 16, 6700AA Wageningen, The Netherlands
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30
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King R, Urban M, Lauder RP, Hawkins N, Evans M, Plummer A, Halsey K, Lovegrove A, Hammond-Kosack K, Rudd JJ. A conserved fungal glycosyltransferase facilitates pathogenesis of plants by enabling hyphal growth on solid surfaces. PLoS Pathog 2017; 13:e1006672. [PMID: 29020037 PMCID: PMC5653360 DOI: 10.1371/journal.ppat.1006672] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 10/23/2017] [Accepted: 09/27/2017] [Indexed: 11/18/2022] Open
Abstract
Pathogenic fungi must extend filamentous hyphae across solid surfaces to cause diseases of plants. However, the full inventory of genes which support this is incomplete and many may be currently concealed due to their essentiality for the hyphal growth form. During a random T-DNA mutagenesis screen performed on the pleomorphic wheat (Triticum aestivum) pathogen Zymoseptoria tritici, we acquired a mutant unable to extend hyphae specifically when on solid surfaces. In contrast "yeast-like" growth, and all other growth forms, were unaffected. The inability to extend surface hyphae resulted in a complete loss of virulence on plants. The affected gene encoded a predicted type 2 glycosyltransferase (ZtGT2). Analysis of >800 genomes from taxonomically diverse fungi highlighted a generally widespread, but discontinuous, distribution of ZtGT2 orthologues, and a complete absence of any similar proteins in non-filamentous ascomycete yeasts. Deletion mutants of the ZtGT2 orthologue in the taxonomically un-related fungus Fusarium graminearum were also severely impaired in hyphal growth and non-pathogenic on wheat ears. ZtGT2 expression increased during filamentous growth and electron microscopy on deletion mutants (ΔZtGT2) suggested the protein functions to maintain the outermost surface of the fungal cell wall. Despite this, adhesion to leaf surfaces was unaffected in ΔZtGT2 mutants and global RNAseq-based gene expression profiling highlighted that surface-sensing and protein secretion was also largely unaffected. However, ΔZtGT2 mutants constitutively overexpressed several transmembrane and secreted proteins, including an important LysM-domain chitin-binding virulence effector, Zt3LysM. ZtGT2 likely functions in the synthesis of a currently unknown, potentially minor but widespread, extracellular or outer cell wall polysaccharide which plays a key role in facilitating many interactions between plants and fungi by enabling hyphal growth on solid matrices.
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Affiliation(s)
- Robert King
- Department of Computational and Analytical Sciences, Rothamsted Research, Harpenden, Herts, United Kingdom
| | - Martin Urban
- Wheat Pathogenomics Team, Department of BioInteractions and Crop Protection, Rothamsted Research, Harpenden, Herts, United Kingdom
| | - Rebecca P. Lauder
- Rothamsted Centre for Bioimaging, Department of Plant Sciences, Rothamsted Research, Harpenden, Herts, United Kingdom
| | - Nichola Hawkins
- Fungicide resistance group, Department of BioInteractions and Crop Protection, Rothamsted Research, Harpenden, Herts, United Kingdom
| | - Matthew Evans
- Cereal cell walls group, Department of Plant Sciences, Rothamsted Research, Harpenden, Herts, United Kingdom
| | - Amy Plummer
- Cereal cell walls group, Department of Plant Sciences, Rothamsted Research, Harpenden, Herts, United Kingdom
| | - Kirstie Halsey
- Rothamsted Centre for Bioimaging, Department of Plant Sciences, Rothamsted Research, Harpenden, Herts, United Kingdom
| | - Alison Lovegrove
- Cereal cell walls group, Department of Plant Sciences, Rothamsted Research, Harpenden, Herts, United Kingdom
| | - Kim Hammond-Kosack
- Wheat Pathogenomics Team, Department of BioInteractions and Crop Protection, Rothamsted Research, Harpenden, Herts, United Kingdom
| | - Jason J. Rudd
- Wheat Pathogenomics Team, Department of BioInteractions and Crop Protection, Rothamsted Research, Harpenden, Herts, United Kingdom
- * E-mail:
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31
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Yemelin A, Brauchler A, Jacob S, Laufer J, Heck L, Foster AJ, Antelo L, Andresen K, Thines E. Identification of factors involved in dimorphism and pathogenicity of Zymoseptoria tritici. PLoS One 2017; 12:e0183065. [PMID: 28829795 PMCID: PMC5568738 DOI: 10.1371/journal.pone.0183065] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 07/28/2017] [Indexed: 01/20/2023] Open
Abstract
A forward genetics approach was applied in order to investigate the molecular basis of morphological transition in the wheat pathogenic fungus Zymoseptoria tritici. Z. tritici is a dimorphic plant pathogen displaying environmentally regulated morphogenetic transition between yeast-like and hyphal growth. Considering the infection mode of Z. tritici, the switching to hyphal growth is essential for pathogenicity allowing the fungus the host invasion through natural openings like stomata. We exploited a previously developed Agrobacterium tumefaciens-mediated transformation (ATMT) to generate a mutant library by insertional mutagenesis including more than 10,000 random mutants. To identify genes involved in dimorphic switch, a plate-based screening system was established. With this approach eleven dimorphic switch deficient random mutants were recovered, ten of which exhibited a yeast-like mode of growth and one mutant predominantly growing filamentously, producing high amount of mycelium under different incubation conditions. Using genome walking approach previously established, the T-DNA integration sites were recovered and the disrupted genomic loci of corresponding mutants were identified and validated within reverse genetics approach. As prove of concept, two of the random mutants obtained were selected for further investigation using targeted gene inactivation. Both genes deduced were found to encode known factors, previously characterized in other fungi: Ssk1p being constituent of HOG pathway and Ade5,7p involved in de novo purine biosynthesis. The targeted mutant strains defective in these genes exhibit a drastically impaired virulence within infection assays on whole wheat plants. Moreover exploiting further physiological assays the predicted function for both gene products could be confirmed in concordance with conserved biological role of homologous proteins previously described in other fungal organisms.
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Affiliation(s)
- Alexander Yemelin
- Institute for Biotechnology and Drug Research (IBWF gGmbH), Kaiserslautern, Germany
| | - Annamaria Brauchler
- Institute of Molecular Physiology, Microbiology and Wine Research, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Stefan Jacob
- Institute for Biotechnology and Drug Research (IBWF gGmbH), Kaiserslautern, Germany
| | - Julian Laufer
- Institute for Biotechnology and Drug Research (IBWF gGmbH), Kaiserslautern, Germany
| | - Larissa Heck
- Institute for Biotechnology and Drug Research (IBWF gGmbH), Kaiserslautern, Germany
| | - Andrew J. Foster
- Institute for Biotechnology and Drug Research (IBWF gGmbH), Kaiserslautern, Germany
| | - Luis Antelo
- Institute of Molecular Physiology, Microbiology and Wine Research, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Karsten Andresen
- Institute of Molecular Physiology, Microbiology and Wine Research, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Eckhard Thines
- Institute for Biotechnology and Drug Research (IBWF gGmbH), Kaiserslautern, Germany
- Institute of Molecular Physiology, Microbiology and Wine Research, Johannes Gutenberg University Mainz, Mainz, Germany
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Abstract
Fungi are among the dominant causal agents of plant diseases. To colonize plants and cause disease, pathogenic fungi use diverse strategies. Some fungi kill their hosts and feed on dead material (necrotrophs), while others colonize the living tissue (biotrophs). For successful invasion of plant organs, pathogenic development is tightly regulated and specialized infection structures are formed. To further colonize hosts and establish disease, fungal pathogens deploy a plethora of virulence factors. Depending on the infection strategy, virulence factors perform different functions. While basically all pathogens interfere with primary plant defense, necrotrophs secrete toxins to kill plant tissue. In contrast, biotrophs utilize effector molecules to suppress plant cell death and manipulate plant metabolism in favor of the pathogen. This article provides an overview of plant pathogenic fungal species and the strategies they use to cause disease.
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Onyilo F, Tusiime G, Chen LH, Falk B, Stergiopoulos I, Tripathi JN, Tushemereirwe W, Kubiriba J, Changa C, Tripathi L. Agrobacterium tumefaciens-Mediated Transformation of Pseudocercospora fijiensis to Determine the Role of PfHog1 in Osmotic Stress Regulation and Virulence Modulation. Front Microbiol 2017; 8:830. [PMID: 28559879 PMCID: PMC5432539 DOI: 10.3389/fmicb.2017.00830] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 04/24/2017] [Indexed: 12/15/2022] Open
Abstract
Black Sigatoka disease, caused by Pseudocercospora fijiensis is a serious constraint to banana production worldwide. The disease continues to spread in new ecological niches and there is an urgent need to develop strategies for its control. The high osmolarity glycerol (HOG) pathway in Saccharomyces cerevisiae is well known to respond to changes in external osmolarity. HOG pathway activation leads to phosphorylation, activation and nuclear transduction of the HOG1 mitogen-activated protein kinases (MAPKs). The activated HOG1 triggers several responses to osmotic stress, including up or down regulation of different genes, regulation of protein translation, adjustments to cell cycle progression and synthesis of osmolyte glycerol. This study investigated the role of the MAPK-encoding PfHog1 gene on osmotic stress adaptation and virulence of P. fijiensis. RNA interference-mediated gene silencing of PfHog1 significantly suppressed growth of P. fijiensis on potato dextrose agar media supplemented with 1 M NaCl, indicating that PfHog1 regulates osmotic stress. In addition, virulence of the PfHog1-silenced mutants of P. fijiensis on banana was significantly reduced, as observed from the low rates of necrosis and disease development on the infected leaves. Staining with lacto phenol cotton blue further confirmed the impaired mycelial growth of the PfHog1 in the infected leaf tissues, which was further confirmed with quantification of the fungal biomass using absolute- quantitative PCR. Collectively, these findings demonstrate that PfHog1 plays a critical role in osmotic stress regulation and virulence of P. fijiensis on its host banana. Thus, PfHog1 could be an interesting target for the control of black Sigatoka disease in banana.
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Affiliation(s)
- Francis Onyilo
- National Agricultural Research LaboratoriesKampala, Uganda
- Department of Agricultural Production, College of Agricultural and Environmental Sciences, Makerere UniversityKampala, Uganda
- International Institute of Tropical AgricultureNairobi, Kenya
| | - Geoffrey Tusiime
- Department of Agricultural Production, College of Agricultural and Environmental Sciences, Makerere UniversityKampala, Uganda
| | - Li-Hung Chen
- Department of Plant Pathology, University of California, Davis, DavisCA, USA
| | - Bryce Falk
- Department of Plant Pathology, University of California, Davis, DavisCA, USA
| | | | | | | | | | - Charles Changa
- National Agricultural Research LaboratoriesKampala, Uganda
| | - Leena Tripathi
- International Institute of Tropical AgricultureNairobi, Kenya
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Ben Jabeur M, Somai-Jemmali L, Hamada W. Thyme essential oil as an alternative mechanism: biofungicide-causing sensitivity ofMycosphaerella graminicola. J Appl Microbiol 2017; 122:932-939. [DOI: 10.1111/jam.13408] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 01/02/2017] [Accepted: 01/24/2017] [Indexed: 11/29/2022]
Affiliation(s)
- M. Ben Jabeur
- Laboratory of Genetic and plant amelioration; National Institute of Agronomy; Tunis Tunisia
| | - L. Somai-Jemmali
- Laboratory of Genetic and plant amelioration; National Institute of Agronomy; Tunis Tunisia
| | - W. Hamada
- Laboratory of Genetic and plant amelioration; National Institute of Agronomy; Tunis Tunisia
- Higher School of Agriculture of Kef; Le Kef Tunisia
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Liu J, Wang ZK, Sun HH, Ying SH, Feng MG. Characterization of the Hog1 MAPK pathway in the entomopathogenic fungus Beauveria bassiana. Environ Microbiol 2017; 19:1808-1821. [PMID: 28076898 DOI: 10.1111/1462-2920.13671] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 01/08/2017] [Accepted: 01/10/2017] [Indexed: 11/27/2022]
Abstract
High-osmolarity glycerol (HOG) pathway required for yeast osmoregulation relies upon the mitogen-activated protein kinase (MAPK) Hog1 cascade that comprise the MAPKKKs Ssk2/Ssk22 and Ste11 converging on the MAPKK Pbs2. Here we show a Hog1 cascade with the unique MAPKKK Ssk2 acting in Beauveria bassiana. Hypersensitivity to high osmolarity and high resistance to fludioxonil fungicide appeared in Δssk2, Δpbs2 and Δhog1 mutants whereas the two hallmark phenotypes were reversed in Δste11. Increased sensitivity to heat shock and decreased sensitivity to cell wall perturbation also occurred in the three mutants but not in Δste11 although antioxidant phenotypes were different in all deletion mutants. Intriguingly, signals of Hog1 phosphorylation induced by osmotic, oxidative and thermal cues were present in Δste11 but absent in Δssk2 and Δpbs2. Moreover, vegetative growth on minimal media with different carbon/nitrogen sources was much more suppressed in Δste11 and Δssk2 than in Δpbs2 and Δhog1 although all mutants suffered similar, but severe, conidiation defects on a standard medium. Normal host infection was abolished in Δste11 while virulence was differentially attenuated in other mutants. Our findings exclude Ste11 from the Hog1 cascade that regulates multiple stress responses and environmental adaptation of B. bassiana and perhaps other filamentous fungi.
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Affiliation(s)
- Jing Liu
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China
| | - Zhi-Kang Wang
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China
| | - Huan-Huan Sun
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China
| | - Sheng-Hua Ying
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China
| | - Ming-Guang Feng
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China
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36
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Mehrabi R, Taga M, Kema GH. Electrophoretic and cytological karyotyping of the foliar wheat pathogenMycosphaerella graminicolareveals many chromosomes with a large size range. Mycologia 2017. [DOI: 10.1080/15572536.2007.11832518] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Rahim Mehrabi
- Wageningen University and Research Centre, Plant Research International B.V., P.O. Box 16, 6700 AA, Wageningen, the Netherlands
| | - Masatoki Taga
- Department of Biology, Faculty of Science, Okayama University, Tsushima-naka, Okayama 700-8530, Japan
| | - Gert H.J. Kema
- Plant Research International B.V., P.O. Box 16, 6700 AA, Wageningen, the Netherlands
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37
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The high osmotic response and cell wall integrity pathways cooperate to regulate morphology, microsclerotia development, and virulence in Metarhizium rileyi. Sci Rep 2016; 6:38765. [PMID: 27941838 PMCID: PMC5150533 DOI: 10.1038/srep38765] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 11/02/2016] [Indexed: 01/28/2023] Open
Abstract
Microsclerotia (MS) formation was successfully induced in Metarhizium rileyi under changing liquid culture conditions. Mitogen-activated protein kinases (MAPKs) play important roles in fungal development and in coordinating many stress responses. To investigate how M. rileyi transduces growth stress and regulates MS differentiation, we characterized the roles of two MAPKs, Hog1- and Slt2-type orthologues, in M. rileyi. Compared with the wild-type strain, the deletion mutants of Mrhog1 (ΔMrhog1) and Mrslt2 (ΔMrslt2) delayed germination and vegetative growth, displayed sensitivities to various stress, and produced morphologically abnormal clones. The ΔMrhog1 and ΔMrslt2 mutants significantly reduced conidial (42–99%) and MS (96–99%) yields. A transcriptional analysis showed that the two MAPKs regulate MS development in a cooperative manner. Insect bioassays revealed that ΔMrhog1 and ΔMrslt2 had decreased virulence levels in topical (36–56%) and injection (78–93%) bioassays. Our results confirmed the roles of MrHog1 and MrSlt2 in sensing growth-related stress and in regulating MS differentiation.
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38
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Jogawat A, Vadassery J, Verma N, Oelmüller R, Dua M, Nevo E, Johri AK. PiHOG1, a stress regulator MAP kinase from the root endophyte fungus Piriformospora indica, confers salinity stress tolerance in rice plants. Sci Rep 2016; 6:36765. [PMID: 27849025 PMCID: PMC5111105 DOI: 10.1038/srep36765] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 10/20/2016] [Indexed: 12/04/2022] Open
Abstract
In this study, yeast HOG1 homologue from the root endophyte Piriformospora indica (PiHOG1) was isolated and functionally characterized. Functional expression of PiHOG1 in S. cerevisiae ∆hog1 mutant restored osmotolerance under high osmotic stress. Knockdown (KD) transformants of PiHOG1 generated by RNA interference in P. indica showed that genes for the HOG pathway, osmoresponse and salinity tolerance were less stimulated in KD-PiHOG1 compared to the wild-type under salinity stress. Furthermore, KD lines are impaired in the colonization of rice roots under salinity stress of 200 mM NaCl, and the biomass of the host plants, their shoot and root lengths, root number, photosynthetic pigment and proline contents were reduced as compared to rice plants colonized by WT P. indica. Therefore, PiHOG1 is critical for root colonisation, salinity tolerance and the performance of the host plant under salinity stress. Moreover, downregulation of PiHOG1 resulted not only in reduced and delayed phosphorylation of the remaining PiHOG1 protein in colonized salinity-stressed rice roots, but also in the downregulation of the upstream MAP kinase genes PiPBS2 and PiSSK2 involved in salinity tolerance signalling in the fungus. Our data demonstrate that PiHOG1 is not only involved in the salinity response of P. indica, but also helping host plant to overcome salinity stress.
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Affiliation(s)
- Abhimanyu Jogawat
- School of Life Sciences Jawaharlal Nehru University, New Delhi-110067, India
| | | | - Nidhi Verma
- School of Life Sciences Jawaharlal Nehru University, New Delhi-110067, India
| | - Ralf Oelmüller
- Institute of Plant Physiology, Friedrich-Schiller-University Jena, Dornburger Str. 159, 07743 Jena, Germany
| | - Meenakshi Dua
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Eviatar Nevo
- Department of Evolutionary and Environmental Biology, Institute of Evolution, University of Haifa, 199 Aba Khoushy Ave., Mount Carmel, Haifa, 3498838, Israel
| | - Atul Kumar Johri
- School of Life Sciences Jawaharlal Nehru University, New Delhi-110067, India
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Tian L, Wang Y, Yu J, Xiong D, Zhao H, Tian C. The Mitogen-Activated Protein Kinase Kinase VdPbs2 of Verticillium dahliae Regulates Microsclerotia Formation, Stress Response, and Plant Infection. Front Microbiol 2016; 7:1532. [PMID: 27729908 PMCID: PMC5037172 DOI: 10.3389/fmicb.2016.01532] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 09/13/2016] [Indexed: 11/13/2022] Open
Abstract
Verticillium dahliae, a ubiquitous phytopathogenic fungus, forms resting structures, known as microsclerotia that play crucial roles in Verticillium wilt diseases. VdHog1, a mitogen-activated protein kinase (MAPK), controls microsclerotia formation, virulence, and stress response in V. dahliae. In this study, we present detailed evidence that the conserved upstream component of VdHog1, VdPbs2, is a key regulator of microsclerotia formation, oxidative stress and fungicide response and plant virulence in V. dahliae. We identified VdPbs2, homologous to the yeast MAPK kinase Pbs2. Similar to the VdHog1 deletion mutant, VdPbs2 deletion strains exhibited delayed melanin synthesis and reduced formation of microsclerotia. When exposed to stresses, VdPbs2 mutants were more sensitive than the wild type to osmotic agents and peroxide, but more resistant to inhibitors of cell wall synthesis and some fungicides. Finally, VdPbs2 deletion mutants exhibited reduced virulence on smoke tree and tobacco seedlings. When taken together, we implicate that VdPbs2 and VdHog1 function in a cascade that regulates microsclerotia formation and virulence, but not all VdHog1 dependent functions are VdPbs2 regulated. This study thus provides novel insights into the signal transduction mechanisms that regulate microsclerotia formation and pathogenesis in this fungus.
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Affiliation(s)
- Longyan Tian
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University Beijing, China
| | - Yonglin Wang
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University Beijing, China
| | - Jun Yu
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University Beijing, China
| | - Dianguang Xiong
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University Beijing, China
| | - Hengjun Zhao
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University Beijing, China
| | - Chengming Tian
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University Beijing, China
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40
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Kou Y, Naqvi NI. Surface sensing and signaling networks in plant pathogenic fungi. Semin Cell Dev Biol 2016; 57:84-92. [DOI: 10.1016/j.semcdb.2016.04.019] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 04/21/2016] [Accepted: 04/26/2016] [Indexed: 11/29/2022]
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41
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UvHOG1 is important for hyphal growth and stress responses in the rice false smut fungus Ustilaginoidea virens. Sci Rep 2016; 6:24824. [PMID: 27095476 PMCID: PMC4837404 DOI: 10.1038/srep24824] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 04/06/2016] [Indexed: 11/23/2022] Open
Abstract
Rice false smut caused by Ustilaginoidea virens is one of the most important diseases of rice worldwide. Although its genome has been sequenced, to date there is no report on targeted gene deletion in U. virens and no molecular studies on genetic mechanisms regulating the infection processes of this destructive pathogen. In this study, we attempted to generate knockout mutants of the ortholog of yeast HOG1 MAP kinase gene in U. virens. One Uvhog1 deletion mutant was identified after screening over 600 hygromycin-resistant transformants generated by Agrobacterium tumefaciens mediated transformation. The Uvhog1 mutant was reduced in growth rate and conidiation but had increased sensitivities to SDS, Congo red, and hyperosmotic stress. Deletion of UvHOG1 resulted in reduced expression of the stress response-related genes UvATF1 and UvSKN7. In the Uvhog1 mutant, NaCl treatment failed to stimulate the accumulation of sorbitol and glycerol. In addition, the Uvhog1 mutant had reduced toxicity on shoot growth in rice seed germination assays. Overall, as the first report of targeted gene deletion mutant in U. virens, our results showed that UvHOG1 likely has conserved roles in regulating stress responses, hyphal growth, and possibly secondary metabolism.
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42
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Lendenmann MH, Croll D, Palma-Guerrero J, Stewart EL, McDonald BA. QTL mapping of temperature sensitivity reveals candidate genes for thermal adaptation and growth morphology in the plant pathogenic fungus Zymoseptoria tritici. Heredity (Edinb) 2016; 116:384-94. [PMID: 26758189 PMCID: PMC4806695 DOI: 10.1038/hdy.2015.111] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 10/01/2015] [Accepted: 11/18/2015] [Indexed: 11/09/2022] Open
Abstract
Different thermal environments impose strong, differential selection on populations, leading to local adaptation, but the genetic basis of thermal adaptation is poorly understood. We used quantitative trait locus (QTL) mapping in the fungal wheat pathogen Zymoseptoria tritici to study the genetic architecture of thermal adaptation and identify candidate genes. Four wild-type strains originating from the same thermal environment were crossed to generate two mapping populations with 263 (cross 1) and 261 (cross 2) progeny. Restriction site-associated DNA sequencing was used to genotype 9745 (cross 1) and 7333 (cross 2) single-nucleotide polymorphism markers segregating within the mapping population. Temperature sensitivity was assessed using digital image analysis of colonies growing at two different temperatures. We identified four QTLs for temperature sensitivity, with unique QTLs found in each cross. One QTL had a logarithm of odds score >11 and contained only six candidate genes, including PBS2, encoding a mitogen-activated protein kinase kinase associated with low temperature tolerance in Saccharomyces cerevisiae. This and other QTLs showed evidence for pleiotropy among growth rate, melanization and growth morphology, suggesting that many traits can be correlated with thermal adaptation in fungi. Higher temperatures were highly correlated with a shift to filamentous growth among the progeny in both crosses. We show that thermal adaptation has a complex genetic architecture, with natural populations of Z. tritici harboring significant genetic variation for this trait. We conclude that Z. tritici populations have the potential to adapt rapidly to climate change and expand into new climatic zones.
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Affiliation(s)
- M H Lendenmann
- Institute of Integrative Biology, Plant Pathology, ETH Zürich, Zürich, Switzerland
| | - D Croll
- Institute of Integrative Biology, Plant Pathology, ETH Zürich, Zürich, Switzerland
| | - J Palma-Guerrero
- Institute of Integrative Biology, Plant Pathology, ETH Zürich, Zürich, Switzerland
| | - E L Stewart
- Institute of Integrative Biology, Plant Pathology, ETH Zürich, Zürich, Switzerland
| | - B A McDonald
- Institute of Integrative Biology, Plant Pathology, ETH Zürich, Zürich, Switzerland
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43
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John E, Lopez-Ruiz F, Rybak K, Mousley CJ, Oliver RP, Tan KC. Dissecting the role of histidine kinase and HOG1 mitogen-activated protein kinase signalling in stress tolerance and pathogenicity of Parastagonospora nodorum on wheat. MICROBIOLOGY-SGM 2016; 162:1023-1036. [PMID: 26978567 PMCID: PMC5042077 DOI: 10.1099/mic.0.000280] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The HOG1 mitogen-activated protein kinase (MAPK) pathway is activated through two-component histidine kinase (HK) signalling. This pathway was first characterized in the budding yeast Saccharomyces cerevisiae as a regulator of osmotolerance. The fungus Parastagonospora nodorum is the causal agent of septoria nodorum blotch of wheat. This pathogen uses host-specific effectors in tandem with general pathogenicity mechanisms to carry out its infection process. Genes showing strong sequence homology to S. cerevisiae HOG1 signalling pathway genes have been identified in the genome of P. nodorum. In this study, we examined the role of the pathway in the virulence of P. nodorum on wheat by disrupting putative pathway component genes: HOG1 (SNOG_13296) MAPK and NIK1 (SNOG_11631) hybrid HK. Mutants deleted in NIK1 and HOG1 were insensitive to dicarboximide and phenylpyrrole fungicides, but not a fungicide that targets ergosterol biosynthesis. Furthermore, both Δnik1 and Δhog1 mutants showed increased sensitivity to hyperosmotic stress. However, HOG1, but not NIK1, is required for tolerance to elevated temperatures. HOG1 deletion conferred increased tolerance to 6-methoxy-2-benzoxazolinone, a cereal phytoalexin. This suggests that the HOG1 signalling pathway is not exclusively associated with NIK1. Both Δnik1 and Δhog1 mutants retained the ability to infect and cause necrotic lesions on wheat. However, we observed that the Δhog1 mutation resulted in reduced production of pycnidia, asexual fruiting bodies that facilitate spore dispersal during late infection. Our study demonstrated the overlapping and distinct roles of a HOG1 MAPK and two-component HK signalling in P. nodorum growth and pathogenicity.
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Affiliation(s)
- Evan John
- Department of Environment and Agriculture, Centre for Crop and Disease Management, Curtin University, Bentley, WA 6102, Australia
| | - Francisco Lopez-Ruiz
- Department of Environment and Agriculture, Centre for Crop and Disease Management, Curtin University, Bentley, WA 6102, Australia
| | - Kasia Rybak
- Department of Environment and Agriculture, Centre for Crop and Disease Management, Curtin University, Bentley, WA 6102, Australia
| | - Carl J Mousley
- School of Biomedical Sciences, CHIRI Biosciences Research Precinct and Faculty of Health Sciences, Curtin University, Bentley, WA 6102, Australia
| | - Richard P Oliver
- Department of Environment and Agriculture, Centre for Crop and Disease Management, Curtin University, Bentley, WA 6102, Australia
| | - Kar-Chun Tan
- Department of Environment and Agriculture, Centre for Crop and Disease Management, Curtin University, Bentley, WA 6102, Australia
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44
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Sidhu YS, Cairns TC, Chaudhari YK, Usher J, Talbot NJ, Studholme DJ, Csukai M, Haynes K. Exploitation of sulfonylurea resistance marker and non-homologous end joining mutants for functional analysis in Zymoseptoria tritici. Fungal Genet Biol 2016; 79:102-9. [PMID: 26092796 PMCID: PMC4502460 DOI: 10.1016/j.fgb.2015.04.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 04/10/2015] [Accepted: 04/13/2015] [Indexed: 11/25/2022]
Abstract
We have constructed Z. tritici ku70 and ku80 null mutants. Gene targeting frequency in the ku null strains is greater than 85%. Deletion of KU70 and KU80 does not affect in vitro growth or pathogenicity. Sulfonylurea resistance was established as a new positive selection marker in Z. tritici. Ternary vectors were constructed to enable yeast recombinational cloning in Z. tritici.
The lack of techniques for rapid assembly of gene deletion vectors, paucity of selectable marker genes available for genetic manipulation and low frequency of homologous recombination are major constraints in construction of gene deletion mutants in Zymoseptoria tritici. To address these issues, we have constructed ternary vectors for Agrobacterium tumefaciens mediated transformation of Z. tritici, which enable the single step assembly of multiple fragments via yeast recombinational cloning. The sulfonylurea resistance gene, which is a mutated allele of the Magnaporthe oryzae ILV2 gene, was established as a new dominant selectable marker for Z. tritici. To increase the frequency of homologous recombination, we have constructed Z. tritici strains deficient in the non-homologous end joining pathway of DNA double stranded break repair by inactivating the KU70 and KU80 genes. Targeted gene deletion frequency increased to more than 85% in both Z. tritici ku70 and ku80 null strains, compared to ⩽10% seen in the wild type parental strain IPO323. The in vitro growth and in planta pathogenicity of the Z. tritici ku70 and ku80 null strains were comparable to strain IPO323. Together these molecular tools add significantly to the platform available for genomic analysis through targeted gene deletion or promoter replacements and will facilitate large-scale functional characterization projects in Z. tritici.
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Affiliation(s)
- Y S Sidhu
- Biosciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - T C Cairns
- Biosciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - Y K Chaudhari
- Biosciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - J Usher
- Biosciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - N J Talbot
- Biosciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - D J Studholme
- Biosciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - M Csukai
- Syngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG426EY, UK
| | - K Haynes
- Biosciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK.
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45
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Sidhu YS, Chaudhari YK, Usher J, Cairns TC, Csukai M, Haynes K. A suite of Gateway® compatible ternary expression vectors for functional analysis in Zymoseptoria tritici. Fungal Genet Biol 2016; 79:180-5. [PMID: 26092805 DOI: 10.1016/j.fgb.2015.03.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 03/20/2015] [Accepted: 03/21/2015] [Indexed: 01/21/2023]
Abstract
Gene overexpression is a widely used functional genomics approach in fungal biology. However, to date it has not been established in Zymoseptoria tritici which is an important pathogen of wheat (Triticum species). Here we report a suite of Gateway® recombination compatible ternary expression vectors for Agrobacterium tumefaciens mediated transformation of Z. tritici. The suite of 32 vectors is based on a combination of four resistance markers for positive selection against glufosinate ammonium, geneticin, hygromycin and sulfonylurea; three constitutive Z. tritici promoters (pZtATUB, pZtGAPDH and pZtTEF) and a nitrogen responsive promoter (pZtNIA1) for controlled expression of the open reading frames. Half of the vectors facilitate expression of proteins tagged with C-terminal EGFP. All 32 vectors allow high frequency targeting of the overexpression cassette into the Ku70 locus and complement the Ku70 gene when transformed into a Z. tritici ku70 null strain, thus circumventing additional phenotypes that can arise from random integration. This suite of ternary expression vectors will be a useful tool for functional analysis through gene overexpression in Z. tritici.
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Affiliation(s)
- Y S Sidhu
- Biosciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - Y K Chaudhari
- Biosciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - J Usher
- Biosciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - T C Cairns
- Biosciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - M Csukai
- Syngenta, Jealotts Hill International Research Centre, Bracknell RG42 6EY, UK
| | - K Haynes
- Biosciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK.
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Cell biology of Zymoseptoria tritici: Pathogen cell organization and wheat infection. Fungal Genet Biol 2016; 79:17-23. [PMID: 26092785 PMCID: PMC4502449 DOI: 10.1016/j.fgb.2015.04.002] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 03/27/2015] [Accepted: 04/02/2015] [Indexed: 01/26/2023]
Abstract
Cell biology of the infection begins to shed light on the host–pathogen interaction. The cell biology of the fungal pathogen is highly understudied. Intensified cell biology research promises new fungicide targets and will help mode-of-action studies.
Cell biological research in the wheat pathogen Zymoseptoria tritici (formerly Mycosphaerella graminicola) has led to a good understanding of the histology of the infection process. Expression profiling and bioinformatic approaches, combined with molecular studies on signaling pathways, effectors and potential necrosis factors provides first insight into the complex interplay between the host and the pathogen. Cell biological studies will help to further our understanding of the infection strategy of the fungus. The cellular organization and intracellular dynamics of the fungus itself is largely unexplored. Insight into essential cellular processes within the pathogen will expand our knowledge of the basic biology of Z. tritici, thereby providing putative new anti-fungal targets.
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47
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Ma W, Kilaru S, Collins C, Courbot M, Steinberg G. Libraries for two-hybrid screening of yeast and hyphal growth forms in Zymoseptoria tritici. Fungal Genet Biol 2016; 79:94-101. [PMID: 26092795 PMCID: PMC4502458 DOI: 10.1016/j.fgb.2015.03.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 03/12/2015] [Accepted: 03/21/2015] [Indexed: 12/22/2022]
Abstract
Pathogenic fungi are constantly emerging resistance to anti-fungal treatments. Therefore, identification of new fungicide targets is important. Good candidates are essential fungal proteins and their regulators. An efficient way to reveal the molecular environment of an essential protein is the search for interacting factors. Here, we establish three yeast two-hybrid libraries, covering yeast and hyphal stages of the wheat pathogen Zymoseptoria tritici. No detectable genomic DNA was present in any of the 3 libraries. Random amplification revealed that the libraries include cDNA fragments of up to 2000bp, suggesting that small-to-medium sized proteins are represented therein. Indeed, full-length cDNAs of five proteins were found in all libraries. The full-length cDNA of large chitin synthase gene mcs1 (5742bp with introns; 5568bp without introns) could not be amplified, but its 5' and 3' regions were represented, suggesting that even larger genes are covered in all libraries. Finally, we tested for the expected interaction of the autophagy proteins ZtAtg4 and ZtAtg8 in Z. tritici, and then used ZtAtg4 to screen one of the two-hybrid libraries. Indeed, we found ZtAtg8 as a positive interaction partner, confirming that interacting proteins can be identified. Thus, these molecular tools promise to be useful in identifying novel fungicide target proteins.
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Affiliation(s)
- W Ma
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - S Kilaru
- Biosciences, University of Exeter, Exeter EX4 4QD, UK.
| | - C Collins
- Shannon Applied Biotechnology Centre, Limerick Institute of Technology, Moylish Park, Limerick, Ireland(2)
| | - M Courbot
- Syngenta Crop Protection AG, Schaffhauserstrasse, 4332 Stein, Switzerland
| | - G Steinberg
- Biosciences, University of Exeter, Exeter EX4 4QD, UK.
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48
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Kilaru S, Schuster M, Latz M, Guo M, Steinberg G. Fluorescent markers of the endocytic pathway in Zymoseptoria tritici. Fungal Genet Biol 2016; 79:150-7. [PMID: 26092801 PMCID: PMC4502447 DOI: 10.1016/j.fgb.2015.03.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 03/12/2015] [Accepted: 03/17/2015] [Indexed: 12/28/2022]
Abstract
We establish Z. tritici fimbrin (ZtFim1) and small GTPases (ZtRab5, ZtRab7) as endocytic markers. All markers localize correctly, proven by live cell imaging and co-staining and pharmaceutical studies. We provide 3 carboxin-resistance conveying vectors for integration of all markers into the sdi1 locus. We provide 3 hygromycin B-resistance conveying vectors for random integration of all markers.
Hyphal growth in filamentous fungi is supported by the uptake (endocytosis) and recycling of membranes and associated proteins at the growing tip. An increasing body of published evidence in various fungi demonstrates that this process is of essential importance for fungal growth and pathogenicity. Here, we introduce fluorescent markers to visualize the endocytic pathway in the wheat pathogen Zymoseptoria tritici. We fused enhanced green-fluorescent protein (eGFP) to the actin-binding protein fimbrin (ZtFim1), which is located in actin patches that are formed at the plasma membrane and are participating in endocytic uptake at the cell surface. In addition, we tagged early endosomes by eGFP-labelling a Rab5-homologue (ZtRab5) and late endosomes and vacuoles by expressing eGFP-Rab7 homologue (ZtRab7). Using fluorescent dyes and live cell imaging we confirmed the dynamic behavior and localization of these markers. This set of molecular tools enables an in-depth phenotypic analysis of Z. tritici mutant strains thereby supporting new strategies towards the goal of controlling wheat against Z. tritici.
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Affiliation(s)
- S Kilaru
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - M Schuster
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - M Latz
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - M Guo
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - G Steinberg
- Biosciences, University of Exeter, Exeter EX4 4QD, UK.
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49
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Bradshaw RE, Guo Y, Sim AD, Kabir MS, Chettri P, Ozturk IK, Hunziker L, Ganley RJ, Cox MP. Genome-wide gene expression dynamics of the fungal pathogen Dothistroma septosporum throughout its infection cycle of the gymnosperm host Pinus radiata. MOLECULAR PLANT PATHOLOGY 2016; 17:210-24. [PMID: 25919703 PMCID: PMC4746707 DOI: 10.1111/mpp.12273] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
We present genome-wide gene expression patterns as a time series through the infection cycle of the fungal pine needle blight pathogen, Dothistroma septosporum, as it invades its gymnosperm host, Pinus radiata. We determined the molecular changes at three stages of the disease cycle: epiphytic/biotrophic (early), initial necrosis (mid) and mature sporulating lesion (late). Over 1.7 billion combined plant and fungal reads were sequenced to obtain 3.2 million fungal-specific reads, which comprised as little as 0.1% of the sample reads early in infection. This enriched dataset shows that the initial biotrophic stage is characterized by the up-regulation of genes encoding fungal cell wall-modifying enzymes and signalling proteins. Later necrotrophic stages show the up-regulation of genes for secondary metabolism, putative effectors, oxidoreductases, transporters and starch degradation. This in-depth through-time transcriptomic study provides our first snapshot of the gene expression dynamics that characterize infection by this fungal pathogen in its gymnosperm host.
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Affiliation(s)
- Rosie E Bradshaw
- Bio-Protection Research Centre, Institute of Fundamental Sciences, Massey University, Palmerston North, 4474, New Zealand
| | - Yanan Guo
- Bio-Protection Research Centre, Institute of Fundamental Sciences, Massey University, Palmerston North, 4474, New Zealand
| | - Andre D Sim
- Bio-Protection Research Centre, Institute of Fundamental Sciences, Massey University, Palmerston North, 4474, New Zealand
| | - M Shahjahan Kabir
- Bio-Protection Research Centre, Institute of Fundamental Sciences, Massey University, Palmerston North, 4474, New Zealand
| | - Pranav Chettri
- Bio-Protection Research Centre, Institute of Fundamental Sciences, Massey University, Palmerston North, 4474, New Zealand
| | - Ibrahim K Ozturk
- Bio-Protection Research Centre, Institute of Fundamental Sciences, Massey University, Palmerston North, 4474, New Zealand
| | - Lukas Hunziker
- Bio-Protection Research Centre, Institute of Fundamental Sciences, Massey University, Palmerston North, 4474, New Zealand
| | - Rebecca J Ganley
- Scion, NZ Forest Research Institute Ltd, Rotorua, 3010, New Zealand
| | - Murray P Cox
- Bio-Protection Research Centre, Institute of Fundamental Sciences, Massey University, Palmerston North, 4474, New Zealand
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50
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Wang Y, Tian L, Xiong D, Klosterman SJ, Xiao S, Tian C. The mitogen-activated protein kinase gene, VdHog1, regulates osmotic stress response, microsclerotia formation and virulence in Verticillium dahliae. Fungal Genet Biol 2016; 88:13-23. [PMID: 26812120 DOI: 10.1016/j.fgb.2016.01.011] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 01/21/2016] [Accepted: 01/21/2016] [Indexed: 10/22/2022]
Abstract
The fungus Verticillium dahliae has gained worldwide notoriety as a destructive plant pathogen, causing vascular wilt diseases on diverse plant species. V. dahliae produces melanized resting bodies, known as microsclerotia, which can survive for 15 years in the soil, and are thus critically important in its disease cycle. However, the molecular mechanisms that underpin microsclerotia formation, survival, and germination remain poorly understood. In this study, we observed that deletion of VdHog1 (ΔVdHog1), encoding a homolog of a high-osmolarity glycerol (HOG) response mitogen-activated protein kinase, displayed decreased numbers of melanized microsclerotia in culture, heightened sensitivity to hyperosmotic stress, and increased resistance to the fungicide fludioxonil. Through RNA-Seq analysis, we identified 221 genes differentially expressed in the ΔVdHog1 strain. Interestingly, the expression levels of genes involved in melanin biosynthesis, as well as the hydrophobin gene VDH1, involved in the early stage of microsclerotia formation, were significantly decreased in the ΔVdHog1 strains relative to the wild-type expression levels. The ΔVdHog1 strains exhibited decreased virulence relative to the wild type strain on smoke tree seedlings. These results indicate that VdHog1 regulates hyperosmotic stress responses in V. dahliae, and establishes the Hog1-mediated pathway as a target to further probe the up- and downstream processes that regulate asexual development in this fungus.
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Affiliation(s)
- Yonglin Wang
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
| | - Longyan Tian
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
| | - Dianguang Xiong
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
| | - Steven J Klosterman
- United States Department of Agriculture-Agricultural Research Service, Salinas, CA, USA
| | - Shuxiao Xiao
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
| | - Chengming Tian
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China.
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