Cross‐species analysis between the maize smut fungi Ustilago maydis and Sporisorium reilianum highlights the role of transcriptional change of effector orthologs for virulence and disease

The emergence of new fungal pathogens threatens sustainable crop production worldwide. One mechanism by which new pathogens may arise is hybridization. To investigate hybridization, the related smut fungi, Ustilago maydis and Sporisorium reilianum, were selected because they both infect Zea mays, can hybridize, and tools are available for their analysis. The hybrid dikaryons of these fungi grew as filaments on plates but their colonization and virulence in Z. mays were reduced compared to the parental dikaryons. The anthocyanin induction caused by the hybrid dikaryon infections was distinct, suggesting its interaction with the host was different from that of the parental dikaryons. Selected virulence genes previously characterized in U. maydis and their predicted S. reilianum orthologs had altered transcript levels during hybrid infection of Z. mays. The downregulated U. maydis effectors, tin2, pit2, and cce1, and transcription factors, rbf1, hdp2, and nlt1, were constitutively expressed in the hybrid. Little impact was observed with increased effector expression; however, increased expression of rbf1 and hdp2, which regulate early pathogenic development by U. maydis, increased the hybrid’s capacity to induce symptoms including the rare induction of small leaf tumors. These results establish a base for investigating molecular aspects of smut fungal hybrid pathogen emergence.

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Mating Type Loci of Sporisorium reilianum: Novel Pattern with Three a and Multiple b Specificities

Eukaryotic Cell ◽

10.1128/ec.4.8.1317-1327.2005 ◽

2005 ◽

Vol 4 (8) ◽

pp. 1317-1327 ◽

Cited By ~ 68

Author(s):

Jan Schirawski ◽

Bernadette Heinze ◽

Martin Wagenknecht ◽

Regine Kahmann

Keyword(s):

Mating Type ◽

Molecular Basis ◽

Plant Invasion ◽

Ustilago Maydis ◽

Smut Fungi ◽

Symptom Development ◽

Receptor System ◽

Mating Partner ◽

Sporisorium Reilianum ◽

High Degree

ABSTRACT Sporisorium reilianum and Ustilago maydis are two closely related smut fungi, which both infect maize but differ fundamentally in their mode of plant invasion and site of symptom development. As a prelude to studying the molecular basis of these differences, we have characterized the mating type loci of S. reilianum. S. reilianum has two unlinked mating type loci, a and b. Genes in both loci and adjacent regions show a high degree of synteny to the corresponding genes of U. maydis. The b locus occurs in at least five alleles and encodes two subunits of a heterodimeric homeodomain transcription factor, while the a locus encodes a pheromone/receptor system. However, in contrast to that of U. maydis, the a locus of S. reilianum exists in three alleles containing two active pheromone genes each. The alleles of the a locus appear to have arisen through recent recombination events within the locus itself. This has created a situation where each pheromone is specific for recognition by only one mating partner.

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Cross-species analysis between the maize smut fungi Ustilago maydis and Sporisorium reilianum highlights the role of transcriptional plasticity of effector orthologs for virulence and disease

10.1101/2020.11.03.366443 ◽

2020 ◽

Cited By ~ 1

Author(s):

Weiliang Zuo ◽

Deepak K Gupta ◽

Jasper RL Depotter ◽

Marco Thines ◽

Gunther Doehlemann

Keyword(s):

Ustilago Maydis ◽

Effector Proteins ◽

Differentially Expressed ◽

Transcriptional Level ◽

Smut Fungi ◽

List Type ◽

Sequencing Analysis ◽

Distinct Disease ◽

Sporisorium Reilianum ◽

Transcriptional Plasticity

SummaryThe constitution and regulation of effector repertoires determines and shapes the outcome of the interaction with the host. Ustilago maydis and Sporisorium reilianum are two closely related smut fungi, which both infect maize, but cause distinct disease symptoms. Understanding how effector orthologs are regulated in these two pathogens can therefore provide insights to pathogen evolution and host adaption.We tracked the infection progress of U. maydis and S. reilianum in maize leaves, characterized two distinct infection stages for cross species RNA-sequencing analysis and identified 207 out of 335 one-to-one effector orthologs being differentially regulated during host colonization, while transcriptional plasticity of the effector orthologs correlated with the distinct disease development strategies.By using CRISPR-Cas9 mediated gene conversion, we identified two differentially expressed effector orthologs with conserved function between two pathogens. Thus, differential expression of functionally conserved genes contributes to species specific adaptation and symptom development. Interestingly, another differentially expressed orthogroup (UMAG_05318/sr1007) showed diverged protein function during speciation, providing a possible case for neofunctionalization.Together, we showed the diversification of effector genes in related pathogens can be caused both by plasticity on the transcriptional level, as well as through neofunctionalization of the encoded effector proteins.

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Cell death in Ustilago maydis: comparison with other fungi and the effect of metformin and curcumin on its chronological lifespan

FEMS Yeast Research ◽

10.1093/femsyr/foaa051 ◽

2020 ◽

Vol 20 (7) ◽

Author(s):

Cinthia V Soberanes-Gutiérrez ◽

Claudia León-Ramírez ◽

Lino Sánchez-Segura ◽

Emmanuel Cordero-Martínez ◽

Julio C Vega-Arreguín ◽

...

Keyword(s):

Cell Death ◽

Culture Media ◽

Model Organism ◽

Ustilago Maydis ◽

Low Concentrations ◽

Sporisorium Reilianum ◽

A Minor ◽

First Time ◽

Positive Effect

ABSTRACT Ustilago maydis is a Basidiomycota fungus, in which very little is known about its mechanisms of cell survival and death. To date, only the role of metacaspase1, acetate and hydrogen peroxide as inducers of cell death has been investigated. In the present work, we analyzed the lifespan of U. maydis compared with other species like Sporisorium reilianum, Saccharomyces cerevisiae and Yarrowia lipolytica, and we observed that U. maydis has a minor lifespan. We probe the addition of low concentrations metformin and curcumin to the culture media, and we observed that both prolonged the lifespan of U. maydis, a result observed for the first time in a phytopathogen fungus. However, higher concentrations of curcumin were toxic for the cells, and interestingly induced the yeast-to-mycelium dimorphic transition. The positive effect of metformin and curcumin appears to be related to an inhibition of the mechanistic Target of Rapamycin (mTOR) pathway, increase expression of autophagy genes and reducing of reactive oxygen species. These data indicate that U. maydis may be a eukaryotic model organism to elucidate the molecular mechanism underlying apoptotic and necrosis pathways, and the lifespan increase caused by metformin and curcumin.

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Pathogenicity Determinants in Smut Fungi Revealed by Genome Comparison

Science ◽

10.1126/science.1195330 ◽

2010 ◽

Vol 330 (6010) ◽

pp. 1546-1548 ◽

Cited By ~ 206

Author(s):

Jan Schirawski ◽

Gertrud Mannhaupt ◽

Karin Münch ◽

Thomas Brefort ◽

Kerstin Schipper ◽

...

Keyword(s):

Pathogenic Fungi ◽

Ustilago Maydis ◽

Genome Comparison ◽

Smut Fungi ◽

Plant Proteins ◽

Virulence Determinants ◽

Closely Related Species ◽

Biotrophic Pathogens ◽

Sporisorium Reilianum ◽

Genomic Regions

Biotrophic pathogens, such as the related maize pathogenic fungi Ustilago maydis and Sporisorium reilianum, establish an intimate relationship with their hosts by secreting protein effectors. Because secreted effectors interacting with plant proteins should rapidly evolve, we identified variable genomic regions by sequencing the genome of S. reilianum and comparing it with the U. maydis genome. We detected 43 regions of low sequence conservation in otherwise well-conserved syntenic genomes. These regions primarily encode secreted effectors and include previously identified virulence clusters. By deletion analysis in U. maydis, we demonstrate a role in virulence for four previously unknown diversity regions. This highlights the power of comparative genomics of closely related species for identification of virulence determinants.

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Ultrastructure of meiosis and the spindle pole body cycle in freeze-substituted basidia of the smut fungi Ustilago maydis and Ustilago avenae

Canadian Journal of Botany ◽

10.1139/b92-081 ◽

1992 ◽

Vol 70 (3) ◽

pp. 629-638 ◽

Cited By ~ 8

Author(s):

Kerry O'Donnell

Keyword(s):

Electron Microscopy ◽

Spindle Pole Body ◽

Ustilago Maydis ◽

Spindle Pole ◽

Meiotic Spindle ◽

Smut Fungi ◽

Late Prophase ◽

Prophase I ◽

Pole Body ◽

Middle Piece

Meiosis in the smut fungi Ustilago maydis and Ustilago avenae (Basidiomycota, Ustilaginales) was studied by electron microscopy of serial-sectioned freeze substituted basidia. At prophase I, a spindle pole body composed of two globular elements connected by a middle piece was attached to the extranuclear surface of each nucleus. Astral and spindle microtubules were initiated at each globular element at late prophase I to prometaphase I. During spindle initiation, the middle piece disappeared and interdigitating half-spindles entered the nucleoplasm, which was surrounded by discontinuous nuclear envelope together with perinuclear endoplasmic reticulum. Kinetochore pairs at metaphase I were analyzed to obtain a karyotype for each species. The meiotic spindle pole body replicational cycle is described. Key words: electron microscopy, freeze-substitution, meiosis, Ustilago, spindle pole body.

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Deletion of ptn1, a PTEN/TEP1 Orthologue, in Ustilago maydis Reduces Pathogenicity and Teliospore Development

Journal of Fungi ◽

10.3390/jof5010001 ◽

2018 ◽

Vol 5 (1) ◽

pp. 1 ◽

Cited By ~ 1

Author(s):

Lalu Vijayakrishnapillai ◽

John Desmarais ◽

Michael Groeschen ◽

Michael Perlin

Keyword(s):

Defense Mechanisms ◽

Developmental Process ◽

Signal Transduction Pathway ◽

Ustilago Maydis ◽

Suppressor Gene ◽

Tumor Formation ◽

Proliferation And Apoptosis ◽

Mating Efficiency ◽

Percent Germination

The PTEN/PI3K/mTOR signal transduction pathway is involved in the regulation of biological processes such as metabolism, cell growth, cell proliferation, and apoptosis. This pathway has been extensively studied in mammals, leading to the conclusion that PTEN is a major tumor suppressor gene. PTEN orthologues have been characterized in a variety of organisms, both vertebrates and non-vertebrates, and studies of the associated PTEN/PI3K/mTOR pathway indicate that it is widely conserved. Studies in fungal systems indicated a role of PTEN in fungal defense mechanisms in Candida albicans, and in the developmental process of sporulation in Saccharomyces cerevisiae. The present study was aimed at investigating the role of the PTEN ortholog, ptn1, in Ustilago maydis, the pathogen of maize. U. maydis ptn1 mutant strains where ptn1 gene is deleted or overexpressed were examined for phenotypes associate with mating, virulence and spore formation. While the overexpression of ptn1 had no substantial effects on virulence, ptn1 deletion strains showed slight reductions in mating efficiency and significant reductions in virulence; tumor formation on stem and/or leaves were severely reduced. Moreover, tumors, when present, had significantly lower levels of mature teliospores, and the percent germination of such spores was similarly reduced. Thus, ptn1 is required for these important aspects of virulence in this fungus.

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Ichthyofauna of streams from the lower Iguaçu River basin, Paraná State, Brazil

Biota Neotropica ◽

10.1590/1676-0611-bn-2015-0117 ◽

2016 ◽

Vol 16 (3) ◽

Cited By ~ 6

Author(s):

Crislei Larentis ◽

Rosilene Luciana Delariva ◽

Louise Cristina Gomes ◽

Dirceu Baumgartner ◽

Igor Paiva Ramos ◽

...

Keyword(s):

River Basin ◽

Fish Fauna ◽

Main Channel ◽

Indicator Species Analysis ◽

Irreversible Loss ◽

Species Analysis ◽

Geomorphological Processes ◽

Nmds Analysis ◽

Iguaçu River

Abstract The drainages of the Iguaçu River basin, as well as the main channel of the river, have peculiar characteristics resulting from geomorphological processes in this area, including the formation of the Iguaçu River Falls. This slope in the lower portion of the basin is a biogeographical barrier to many organisms. In this study was inventoried the fish fauna of streams of the lower Iguaçu River basin, evaluating possible differences in the species composition upstream and downstream of this biogeographical barrier. Sampling were conducted between 2004 and 2013, in five streams, three upstream and two downstream of the Iguaçu River Falls, using electrofishing. The nMDS analysis was run to investigate possible groupings of similar fauna between the streams sampled. The scores of this test were tested as to the significance of groupings with the Hotelling T2 test. The indicator value method (IndVal) was used to detect the distribution of species among the groups of the streams upstream and downstream of the Iguaçu River Falls. We collected 18,908 individuals of six orders, 11 families, and 40 species. Siluriformes and Characiformes had the highest species richness; Cyprinodontiformes presented the highest abundance. Considering the species recorded, 21 are considered natives to the Iguaçu River basin, including 15 endemic, wich were found only in streams upstream of the falls. Additional 18 species were verified only in the streams downstream of such barrier. Four species were common to both stretches. The axis 1 of the nMDS separated two groups: streams upstream (S1, S2 and S3) and streams downstream of the Iguaçu River Falls (S4 and S5). The indicator species analysis also indicated a distinction between the groups of streams, that were significantly different (Hotelling's T2 = 234.36, p ˂ 0.0001). The number of endemic species in the streams upstream of the Falls (15 spp.) evidences a significant effect of isolation promoted by the Iguaçu River Falls, and confirms the role of this barrier in the vicariant processes and endemism typical of this basin. These results emphasize the importance of conserving these ecosystems, once the extinction of species in this region means the irreversible loss of them.

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