| 1. |
- Melin, Petter, et al.
(författare)
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Characterization of phiA, a gene essential for phialide development in Aspergillus nidulans
- 2003
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Ingår i: Fungal Genetics and Biology. - : Academic Press. - 1087-1845 .- 1096-0937. ; 40:3, s. 234-241
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Tidskriftsartikel (refereegranskat)abstract
- We have previously identified genes and proteins involved in the fungal response to the Streptomyces-produced antibiotics, bafilomycin 131 and concanamycin A, known inhibitors of V-ATPases. Using mRNA differential display we identified an Aspergillus nidulans gene with 30-fold up-regulated expression in the presence of bafilomycin. This gene, here denoted phiA, and its gene product, were further characterized by targeted gene disruption and immunohistochemistry. Phenotypically, the phiA mutation resulted in reduced growth and severely reduced sporulation. The abnormality could be traced to the phialides, which divided several times instead of forming a single flask-shaped cell. The importance of phiA for phialide and conidium development was supported by immunohistochemistry experiments that showed the protein to be mainly present in these two cell types. Attempts to relate phiA to inhibition of V-ATPases did not result in unambiguous conclusions, but suggest the possibility that changed expression of phiA is correlated with growth arrest caused by inhibited V-ATPases.
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| 2. |
- Andersen, M.R., et al.
(författare)
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Current status of systems biology in Aspergilli
- 2009
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Ingår i: Fungal Genetics and Biology. - : Elsevier BV. - 1096-0937 .- 1087-1845. ; 46:584-590, s. 180-190
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Tidskriftsartikel (refereegranskat)abstract
- Saccharomyces cerevisiae is a unicellular eukaryal microorganism that has traditionally been regarded either as a model system for investigating cellular physiology or as a cell factory for biotechnological use, for example for the production of fuels and commodity chemicals such as lactate or pharmaceuticals, including human insulin and HPV vaccines. Systems biology has recently gained momentum and has successfully been used for mapping complex regulatory networks and resolving the dynamics of signal transduction pathways. So far, yeast systems biology has mainly focused on the development of new methods and concepts. There are also some examples of the application of yeast systems biology for improving biotechnological processes. We discuss here how yeast systems biology could be used in elucidating fundamental cellular principles such as those relevant for the study of molecular mechanisms underlying complex human diseases, including the metabolic syndrome and ageing.
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| 3. |
- Brandström Durling, Mikael, et al.
(författare)
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Fungal cross-talk: an integrated approach to study distance communication
- 2021
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Ingår i: Fungal Genetics and Biology. - : Elsevier BV. - 1087-1845 .- 1096-0937. ; 148
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Tidskriftsartikel (refereegranskat)abstract
- Despite the interest on fungi as eukaryotic model systems, the molecular mechanisms regulating the fungal nonself-recognition at a distance have not been studied so far. This paper investigates the molecular mechanisms regulating the cross-talk at a distance between two filamentous fungi, Trichoderma gamsii and Fusarium graminearum which establish a mycoparasitic interaction where T. gamsii and F. graminearum play the roles of mycoparasite and prey, respectively. In the present work, we use an integrated approach involving dual culture tests, comparative genomics and transcriptomics to investigate the fungal interaction before contact ('sensing phase').Dual culture tests demonstrate that growth rate of F. graminearum accelerates in presence of T. gamsii at the sensing phase. T. gamsii up-regulates the expression of a ferric reductase involved in iron acquisition, while F. graminearum up-regulates the expression of genes coding for transmembrane transporters and killer toxins. At the same time, T. gamsii decreases the level of extracellular interaction by down-regulating genes coding for hydrolytic enzymes acting on fungal cell wall (chitinases).Given the importance of fungi as eukaryotic model systems and the ever-increasing genomic resources available, the integrated approach hereby presented can be applied to other interactions to deepen the knowledge on fungal communication at a distance.
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| 4. |
- Chen, Hongxin, et al.
(författare)
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A cerato-platanin-like protein HaCPL2 from Heterobasidion annosum sensu stricto induces cell death in Nicotiana tabacum and Pinus sylvestris
- 2015
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Ingår i: Fungal Genetics and Biology. - : Elsevier BV. - 1087-1845 .- 1096-0937. ; 84, s. 41-51
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Tidskriftsartikel (refereegranskat)abstract
- The cerato-platanin family is a group of small secreted cysteine-rich proteins exclusive for filamentous fungi. They have been shown to be involved in the interactions between fungi and plants. Functional characterization of members from this family has been performed mainly in Ascomycota, except Moniliophthora perniciosa. Our previous phylogenetic analysis revealed that recent gene duplication of cerato-platanins has occurred in Basidiomycota but not in Ascomycota, suggesting higher functional diversification of this protein family in Basidiomycota than in Ascomycota. In this study, we identified three cerato-platanin homologues from the basidiomycete conifer pathogen Heterobasidion annosum sensu stricto. Expression of the homologues under various conditions as well as their roles in the H. annosum s.s.-Pinus sylvestris (Scots pine) pathosystem was investigated. Results showed that HaCPL2 (ceratoplatanin-like protein 2) had the highest sequence similarity to cerato-platanin from Ceratocystis platani and hacpl2 was significantly induced during nutrient starvation and necrotrophic growth. The treatment with recombinant HaCPL2 induced cell death, phytoalexin production and defense gene expression in Nicotiana tabacum. Eliciting and cell death-inducing ability accompanied by retardation of apical root growth was also demonstrated in Scots pine seedlings. Our results suggest that HaCPL2 might contribute to the virulence of H. annosum s.s. by promoting plant cell death.
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| 5. |
- Coutinho, P. M., et al.
(författare)
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Post-genomic insights into the plant polysaccharide degradation potential of Aspergillus nidulans and comparison to Aspergillus niger and Aspergillus oryzae
- 2009
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Ingår i: Fungal Genetics and Biology. - : Elsevier BV. - 1096-0937 .- 1087-1845. ; 46:Suppl 1, s. S161-S169
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Tidskriftsartikel (refereegranskat)abstract
- The plant polysaccharide degradative potential of Aspergillus nidulans was analysed in detail and compared to that of Aspergillus niger and Aspergillus oryzae using a combination of bioinformatics, physiology and transcriptomics. Manual verification indicated that 28.4% of the A. nidulans ORFs analysed in this study do not contain a secretion signal, of which 40% may be secreted through a non-classical method. While significant differences were found between the species in the numbers of ORFs assigned to the relevant CAZy families, no significant difference was observed in growth on polysaccharides. Growth differences were observed between the Aspergilli and Podospora anserina, which has a more different genomic potential for polysaccharide degradation, suggesting that large genomic differences are required to cause growth differences oil polysaccharides, Differences were also detected between the Aspergilli in the presence Of putative regulatory sequences in the promoters of the ORFs Of this Study and correlation of the presence Of putative XlnR binding sites to induction by xylose was detected for A. niger. These data demonstrate differences at genome content, Substrate specificity of the enzymes and gene regulation in these three Aspergilli, which likely reflect their individual adaptation to their natural biotope. (C) 2008 Elsevier Inc. All rights reserved.
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| 6. |
- Davydenko, Kateryna, et al.
(författare)
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Looking for relationships between the populations of Dothistroma septosporum in northern Europe and Asia
- 2018
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Ingår i: Fungal Genetics and Biology. - : Elsevier BV. - 1087-1845 .- 1096-0937. ; 110, s. 15-25
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Tidskriftsartikel (refereegranskat)abstract
- Dothistroma septosporum, a notorious pine needle pathogen with an unknown historical geographic origin and poorly known distribution pathways, is nowadays found almost in all areas inhabited by pines (Pinus spp.). The main aim of this study was to determine the relationship between North European and East Asian populations. In total, 238 Eurasian D. septosporum isolates from 11 countries, including 211 isolates from northern Europe, 16 isolates from Russian Far East and 11 isolates from Bhutan were analysed using 11 species-specific microsatellite and mating type markers. The most diverse populations were found in northern Europe, including the Baltic countries, Finland and European Russia. Notably, D. septosporum has not caused heavy damage to P. sylvestris in northern Europe, which may suggest a long co-existence of the host and the pathogen. No indication was obtained that the Russian Far East or Bhutan could be the indigenous area of D. septosporum, as the genetic diversity of the fungus there was low and evidence suggests gene flow from northern Europe to Russian Far East. On the western coast of Norway, a unique genetic pattern was observed, which differed from haplotypes dominating other Fennoscandian populations. As an agent of dothistroma needle blight, only D. septosporum was documented in northern Europe and Asia, while D. pini was found in Ukraine and Serbia.
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| 7. |
- Diéguez-Uribeondo, Javier, et al.
(författare)
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Phylogenetic relationships among plant and animal parasites, and saprotrophs in Aphanomyces (Oomycetes)
- 2009
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Ingår i: Fungal Genetics and Biology. - : Elsevier BV. - 1087-1845 .- 1096-0937. ; 46:5, s. 365-376
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Tidskriftsartikel (refereegranskat)abstract
- Molecular phylogenetic relationships among 12 species of Aphanomyces de Bary (Oomycetes) were analyzed based on 108 ITS sequences of nuclear rDNA. Sequences used in the analyses belonged to the major species currently available in pure culture and GenBank. Bayesian, maximum likelihood, and maximum parsimony analyses support that Aphanomyces constitutes a monophyletic group. Three independent lineages were found: (i) plant parasitic, (ii) animal parasitic, and (iii) saprotrophic or opportunistic parasitic. Sexual reproduction appeared to be critical in plant parasites for survival in soil environments while asexual reproduction seemed to be advantageous for exploiting specialization in animal parasitism. Repeated zoospore emergence seems to be an advantageous property for both plant and animal parasitic modes of life. Growth in unspecific media was generally faster in saprotrophs compared with parasitic species. A number of strains and GenBank sequences were found to be misidentified. It was confirmed molecularly that Aphanomyces piscicida and Aphanomyces invadans appear to be conspecific, and found that Aphanomyces iridis and Aphanomyces euteiches are closely related, if not the same, species. This study has shown a clear evolutionary separation between Aphanomyces species that are plant parasites and those that parasitize animals. Saprotrophic or opportunistic species formed a separate evolutionary lineage except Aphanomyces stellatus whose evolutionary position has not yet been resolved.
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| 8. |
- Diéguez-Uribeondo, Javier, et al.
(författare)
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Re-evaluation of the enigmatic species complex Saprolegnia diclina-Saprolegnia parasitica based on morphological, physiological and molecular data
- 2007
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Ingår i: Fungal Genetics and Biology. - : Elsevier BV. - 1087-1845 .- 1096-0937. ; 44:7, s. 585-601
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Tidskriftsartikel (refereegranskat)abstract
- The phylogenetic relationships among isolates of the Saprolegnia diclina-Saprolegnia parasitica complex were investigated based on ITS rDNA sequences, and correlated with morphological and physiological characters. The isolates studied belong to five phylogenetically separate clades. The majority of presumed parasitic isolates, mostly isolated from fish lesions, fell within a clade that comprises isolates which has been variously named as S. diclina Type 1, S. parasitica, Saprolegnia salmonis or just as unnamed Saprolegnia sp. Presence of bundles of long-hooked hairs on secondary cysts, high frequency of retracted germination, and oogonia production at 7 degrees C (when occurring) were characteristic of this clade. A single isolate identified as S. diclina Type 2 clustered in a clade along with Saprolegnia ferax isolates. The isolates identified as S. diclina s. str. (S. diclina Type 3) distributed in two clades and appeared closely related to Saprolegnia multispora and to a number of Chilean isolates identified as Saprolegnia australis. The ITS sequences of clade I were almost identical even though the isolates were of diverse geographical origins and showed physiological and morphological differences and variations in their pathogenicity. This suggest these species reproduces clonally even in apparently sexually competent isolates. Adaptation to parasitism in Saprolegnia might have occurred at spore level by the development of long-hooked hairs to facilitate host attachment and selection of a retracting germination. The use of the name S. parasitica should be assigned to isolates of clade I that contained isolates forming cysts with bundles of long-hooked hairs.
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| 9. |
- Dubey, Mukesh, et al.
(författare)
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The glyoxylate cycle is involved in pleotropic phenotypes, antagonism and induction of plant defence responses in the fungal biocontrol agent Trichoderma atroviride
- 2013
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Ingår i: Fungal Genetics and Biology. - : Elsevier BV. - 1087-1845 .- 1096-0937. ; 58-59, s. 33-41
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Tidskriftsartikel (refereegranskat)abstract
- Isocitrate lyase (ICL), a signature enzyme of the glyoxylate cycle, is required for metabolism of non-fermentable carbon compounds like acetate or ethanol, and virulence in bacteria and fungi. In the present study, we investigate the role of the glyoxylate cycle in the fungal biocontrol agent Trichoderma atroviride by generating id deletion and complementation mutants. Phenotypic analyses of the deletion mutant Delta icl suggest that ICL is required for normal growth, conidial pigmentation and germination, and abiotic stress tolerance. The Delta icl strain display reduced antagonism towards Botrytis cinerea in plate confrontation assays. Secretion and sandwich assays further show that secreted factors are partly responsible for the reduced antagonism. Furthermore, in vitro root colonization assays shows that the Delta icl strain retains the ability to internally colonize Arabidopsis thaliana roots. However, the Delta icl strain has a reduced ability to induce systemic defence in A. thaliana leaves that results in reduced protection against B. cinerea. These data shows that ICL and the glyoxylate cycle are important for biocontrol traits in T. atroviride, including direct antagonism and induction of defence responses in plants.
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| 10. |
- Fugelstad, Johanna, et al.
(författare)
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Identification of the cellulose synthase genes from the Oomycete Saprolegnia monoica and effect of cellulose synthesis inhibitors on gene expression and enzyme activity
- 2009
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Ingår i: Fungal Genetics and Biology. - : Elsevier BV. - 1087-1845 .- 1096-0937. ; 46:10, s. 759-767
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Tidskriftsartikel (refereegranskat)abstract
- Cellulose biosynthesis is a vital but yet poorly understood biochemical process in Oomycetes. Here, we report the identification and characterization of the cellulose synthase genes (CesA) from Saprolegnia monoica. Southern blot experiments revealed the occurrence of three CesA homologues in this species and phylogenetic analyses confirmed that Oomycete CesAs form a clade of their own. All gene products contained the D,D,D,QXXRW signature of most processive glycosyltransferases, including cellulose synthases. However, their N-terminal ends exhibited Oomycete-specific domains, i.e. Pleckstrin Homology domains, or conserved domains of an unknown function together with additional putative transmembrane domains. Mycelial growth was inhibited in the presence of the cellulose biosynthesis inhibitors 2,6-dichlorobenzonitrile or Congo Red. This inhibition was accompanied by a higher expression of all CesA genes in the mycelium and increased in vitro glucan synthase activities. Altogether, our data strongly suggest a direct involvement of the identified CesA genes in cellulose biosynthesis.
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