1
|
de Oliveira TC, Freyria NJ, Sarmiento-Villamil JL, Porth I, Tanguay P, Bernier L. Unraveling the transcriptional features and gene expression networks of pathogenic and saprotrophic Ophiostoma species during the infection of Ulmus americana. Microbiol Spectr 2024; 12:e0369423. [PMID: 38230934 PMCID: PMC10845970 DOI: 10.1128/spectrum.03694-23] [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: 10/17/2023] [Accepted: 12/08/2023] [Indexed: 01/18/2024] Open
Abstract
American elm (Ulmus americana), highly prized for its ornamental value, has suffered two successive outbreaks of Dutch elm disease (DED) caused by ascomycete fungi belonging to the genus Ophiostoma. To identify the genes linked to the pathogenicity of different species and lineages of Ophiostoma, we inoculated 2-year-old U. americana saplings with six strains representing three species of DED fungi, and one strain of the saprotroph Ophiostoma quercus. Differential expression analyses were performed following RNA sequencing of fungal transcripts recovered at 3- and 10-days post-infection. Based on a total of 8,640 Ophiostoma genes, we observed a difference in fungal gene expression depending on the strain inoculated and the time of incubation in host tissue. Some genes overexpressed in the more virulent strains of Ophiostoma encode hydrolases that possibly act synergistically. A mutant of Ophiostoma novo-ulmi in which the gene encoding the ogf1 transcription factor had been deleted did not produce transcripts for the gene encoding the hydrophobin cerato-ulmin and was less virulent. Weighted gene correlation network analyses identified several candidate pathogenicity genes distributed among 13 modules of interconnected genes.IMPORTANCEOphiostoma is a genus of cosmopolitan fungi that belongs to the family Ophiostomataceae and includes the pathogens responsible for two devastating pandemics of Dutch elm disease (DED). As the mechanisms of action of DED agents remain unclear, we carried out the first comparative transcriptomic study including representative strains of the three Ophiostoma species causing DED, along with the phylogenetically close saprotrophic species Ophiostoma quercus. Statistical analyses of the fungal transcriptomes recovered at 3 and 10 days following infection of Ulmus americana saplings highlighted several candidate genes associated with virulence and host-pathogen interactions wherein each strain showed a distinct transcriptome. The results of this research underscore the importance of investigating the transcriptional behavior of different fungal taxa to understand their pathogenicity and virulence in relation to the timeline of infection.
Collapse
Affiliation(s)
- Thais C. de Oliveira
- Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, Quebec, Canada
- Centre d’étude de la Forêt, Faculté de foresterie, de géographie et de géomatique, Université Laval, Québec, Quebec, Canada
| | - Nastasia J. Freyria
- Department of Natural Resource Sciences, McGill University, St. Anne-de-Bellevue, Quebec, Quebec, Canada
| | - Jorge Luis Sarmiento-Villamil
- Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, Quebec, Canada
- Centre d’étude de la Forêt, Faculté de foresterie, de géographie et de géomatique, Université Laval, Québec, Quebec, Canada
- Instituto de Hortofruticultura Subtropical y Mediterránea, Consejo Superior de Investigaciones Científicas-Universidad de Málaga (IHSM-CSIC-UMA), Estación Experimental “La Mayora”, Málaga, Spain
| | - Ilga Porth
- Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, Quebec, Canada
- Centre d’étude de la Forêt, Faculté de foresterie, de géographie et de géomatique, Université Laval, Québec, Quebec, Canada
| | - Philippe Tanguay
- Canadian Forest Service, Natural Resources Canada, Laurentian Forestry Centre, Québec, Quebec, Canada
| | - Louis Bernier
- Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, Quebec, Canada
- Centre d’étude de la Forêt, Faculté de foresterie, de géographie et de géomatique, Université Laval, Québec, Quebec, Canada
| |
Collapse
|
2
|
Kijpornyongpan T, Aime MC. Comparative transcriptomics reveal different mechanisms for hyphal growth across four plant-associated dimorphic fungi. Fungal Genet Biol 2021; 152:103565. [PMID: 33991665 DOI: 10.1016/j.fgb.2021.103565] [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: 09/24/2020] [Revised: 03/07/2021] [Accepted: 05/03/2021] [Indexed: 11/27/2022]
Abstract
Fungal dimorphism is a phenomenon by which a fungus can grow both as a yeast form and a hyphal form. It is frequently related to pathogenicity as different growth forms are more suitable for different functions during a life cycle. Among dimorphic plant pathogens, the corn smut fungus Ustilago maydis serves as a model organism to understand fungal dimorphism and its effect on pathogenicity. However, there is a lack of data on whether mechanisms elucidated from model species are broadly applicable to other fungi. In this study, two non-model plant-associated species in the smut fungus subphylum (Ustilaginomycotina), Tilletiopsis washingtonensis and Meira miltonrushii, were selected to compare dimorphic mechanisms in these to those in U. maydis. We sequenced transcriptomic profiles during both yeast and hyphal growth in these two species using Tween40, a lipid mimic, as a trigger for hyphal growth. We then compared our data with previously published data from U. maydis and a fourth but unrelated dimorphic phytopathogen, Ophiostoma novo-ulmi. Comparative transcriptomics was performed to identify common genes upregulated during hyphal growth in all four dimorphic species. Intriguingly, T. washingtonensis shares the least similarities of transcriptomic alteration (hyphal growth versus yeast growth) with the others, although it is closely related to M. miltonrushii and U. maydis. This suggests that phylogenetic relatedness is not correlated with transcriptomic similarity under the same biological phenomenon. Among commonly expressed genes in the four species, genes in cell energy production and conversion, amino acid transport and metabolism and cytoskeleton are significantly enriched. Considering dimorphism genes characterized in U. maydis, as well as hyphal tip-associated genes from the literature, we found only genes encoding the cell end marker Tea4/TeaC and the kinesin motor protein Kin3 concordantly expressed in all four species. This suggests a divergence in species-specific mechanisms for dimorphic transition and hyphal growth.
Collapse
Affiliation(s)
- Teeratas Kijpornyongpan
- Department of Botany and Plant Pathology, Purdue University, 915 W State St, West Lafayette, IN 47907-2054, USA
| | - M Catherine Aime
- Department of Botany and Plant Pathology, Purdue University, 915 W State St, West Lafayette, IN 47907-2054, USA.
| |
Collapse
|
3
|
Tronnolone H, Gardner JM, Sundstrom JF, Jiranek V, Oliver SG, Binder BJ. Quantifying the dominant growth mechanisms of dimorphic yeast using a lattice-based model. J R Soc Interface 2018; 14:rsif.2017.0314. [PMID: 28954849 DOI: 10.1098/rsif.2017.0314] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Accepted: 08/31/2017] [Indexed: 12/22/2022] Open
Abstract
A mathematical model is presented for the growth of yeast that incorporates both dimorphic behaviour and nutrient diffusion. The budding patterns observed in the standard and pseudohyphal growth modes are represented by a bias in the direction of cell proliferation. A set of spatial indices is developed to quantify the morphology and compare the relative importance of the directional bias to nutrient concentration and diffusivity on colony shape. It is found that there are three different growth modes: uniform growth, diffusion-limited growth (DLG) and an intermediate region in which the bias determines the morphology. The dimorphic transition due to nutrient limitation is investigated by relating the directional bias to the nutrient concentration, and this is shown to replicate the behaviour observed in vivo Comparisons are made with experimental data, from which it is found that the model captures many of the observed features. Both DLG and pseudohyphal growth are found to be capable of generating observed experimental morphologies.
Collapse
Affiliation(s)
- Hayden Tronnolone
- School of Mathematical Sciences, Waite Campus, University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Jennifer M Gardner
- Department of Wine and Food Science, Waite Campus, University of Adelaide, Urrbrae, SA 5064, Australia
| | - Joanna F Sundstrom
- Department of Wine and Food Science, Waite Campus, University of Adelaide, Urrbrae, SA 5064, Australia
| | - Vladimir Jiranek
- Department of Wine and Food Science, Waite Campus, University of Adelaide, Urrbrae, SA 5064, Australia
| | - Stephen G Oliver
- Cambridge Systems Biology Centre and Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK
| | - Benjamin J Binder
- School of Mathematical Sciences, Waite Campus, University of Adelaide, Adelaide, South Australia 5005, Australia
| |
Collapse
|