scholarly journals Manipulating the Expression of Small Secreted Protein 1 (Ssp1) Alters Patterns of Development and Metabolism in the White-Rot FungusPleurotus ostreatus

2019 ◽  
Vol 85 (15) ◽  
Author(s):  
Daria Feldman ◽  
Nadav Amedi ◽  
Shmuel Carmeli ◽  
Oded Yarden ◽  
Yitzhak Hadar
Keyword(s):  
Secondary Metabolism ◽  
Fruiting Body ◽  
Pleurotus Ostreatus ◽  
Expression Patterns ◽  
White Rot ◽  
Secreted Proteins ◽  
Time Shift ◽  
Fungal Development ◽  
Content Type ◽  
Small Secreted Proteins

ABSTRACTThe function of small secreted proteins (SSPs) in saprotrophic fungi is, for the most part, unknown. The white-rot mushroomPleurotus ostreatusproduces considerable amounts of SSPs at the onset of secondary metabolism, during colony development, and in response to chemical compounds such as 5-hydroxymethylfurfural and aryl alcohols. Genetic manipulation of Ssp1, by knockdown (KDssp1) or overexpression (OEssp1), indicated that they are, in fact, involved in the regulation of the ligninolytic system. To elucidate their potential involvement in fungal development, quantitative secretome analysis was performed during the trophophase and the idiophase and at a transition point between the two growth phases. The mutations conferred a time shift in the secretion and expression patterns: OEssp1preceded the entrance to idiophase and secondary metabolism, while KDssp1was delayed. This was also correlated with expression patterns of selected genes. The KDssp1colony aged at a slower pace, accompanied by a slower decline in biomass over time. In contrast, the OEssp1strain exhibited severe lysis and aging of the colony at the same time point. These phenomena were accompanied by variations in yellow pigment production, characteristic of entrance of the wild type into idiophase. The pigment was produced earlier and in a larger amount in the OEssp1strain and was absent from the KDssp1strain. Furthermore, the dikaryon harboring OEssp1exhibited a delay in the initiation of fruiting body formation as well as earlier aging. We propose that Ssp1 might function as a part of the fungal communication network and regulate the pattern of fungal development and metabolism inP. ostreatus.IMPORTANCESmall secreted proteins (SSPs) are common in fungal saprotrophs, but their roles remain elusive. As such, they comprise part of a gene pool which may be involved in governing fungal lifestyles not limited to symbiosis and pathogenicity, in which they are commonly referred to as “effectors.” We propose that Ssp1 in the white-rot fungusPleurotus ostreatusregulates the transition from primary to secondary metabolism, development, aging, and fruiting body initiation. Our observations uncover a novel regulatory role of effector-like SSPs in a saprotroph, suggesting that they may act in fungal communication as well as in response to environmental cues. The presence of Ssp1 homologues in other fungal species supports a common potential role in environmental sensing and fungal development.

scholarly journals Gene Expression Patterns of Wood Decay Fungi Postia placenta and Phanerochaete chrysosporium Are Influenced by Wood Substrate Composition during Degradation

2016 ◽  
Vol 82 (14) ◽  
pp. 4387-4400 ◽  
Author(s):  
Oleksandr Skyba ◽  
Dan Cullen ◽  
Carl J. Douglas ◽  
Shawn D. Mansfield
Keyword(s):  
Gene Expression ◽  
Expression Patterns ◽  
White Rot Fungi ◽  
Wood Decay ◽  
White Rot ◽  
Decay Fungi ◽  
Content Type ◽  
Postia Placenta ◽  
Substrate Composition ◽  
Wood Decay Fungi

ABSTRACTIdentification of the specific genes and enzymes involved in the fungal degradation of lignocellulosic biomass derived from feedstocks with various compositions is essential to the development of improved bioenergy processes. In order to elucidate the effect of substrate composition on gene expression in wood-rotting fungi, we employed microarrays based on the annotated genomes of the brown- and white-rot fungi,Rhodonia placenta(formerlyPostia placenta) andPhanerochaete chrysosporium, respectively. We monitored the expression of genes involved in the enzymatic deconstruction of the cell walls of three 4-year-oldPopulus trichocarpa(poplar) trees of genotypes with distinct cell wall chemistries, selected from a population of several hundred trees grown in a common garden. The woody substrates were incubated with wood decay fungi for 10, 20, and 30 days. An analysis of transcript abundance in all pairwise comparisons highlighted 64 and 84 differentially expressed genes (>2-fold,P< 0.05) inP. chrysosporiumandP. placenta, respectively. Cross-fungal comparisons also revealed an array of highly differentially expressed genes (>4-fold,P< 0.01) across different substrates and time points. These results clearly demonstrate that gene expression profiles ofP. chrysosporiumandP. placentaare influenced by wood substrate composition and the duration of incubation. Many of the significantly expressed genes encode “proteins of unknown function,” and determining their role in lignocellulose degradation presents opportunities and challenges for future research.IMPORTANCEThis study describes the variation in expression patterns of two wood-degrading fungi (brown- and white-rot fungi) during colonization and incubation on three different naturally occurring poplar substrates of differing chemical compositions, over time. The results clearly show that the two fungi respond differentially to their substrates and that several known and, more interestingly, currently unknown genes are highly misregulated in response to various substrate compositions. These findings highlight the need to characterize several unknown proteins for catalytic function but also as potential candidate proteins to improve the efficiency of enzymatic cocktails to degrade lignocellulosic substrates in industrial applications, such as in a biochemically based bioenergy platform.

scholarly journals Induction of Genes Encoding Plant Cell Wall-Degrading Carbohydrate-Active Enzymes by Lignocellulose-Derived Monosaccharides and Cellobiose in the White-Rot FungusDichomitus squalens

2018 ◽  
Vol 84 (11) ◽  
Author(s):  
Sara Casado López ◽  
Mao Peng ◽  
Tedros Yonatan Issak ◽  
Paul Daly ◽  
Ronald P. de Vries ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Plant Biomass ◽  
Expression Patterns ◽  
Fine Tuning ◽  
White Rot ◽  
White Rot Fungus ◽  
Content Type ◽  
Dichomitus Squalens

ABSTRACTFungi can decompose plant biomass into small oligo- and monosaccharides to be used as carbon sources. Some of these small molecules may induce metabolic pathways and the production of extracellular enzymes targeted for degradation of plant cell wall polymers. Despite extensive studies in ascomycete fungi, little is known about the nature of inducers for the lignocellulolytic systems of basidiomycetes. In this study, we analyzed six sugars known to induce the expression of lignocellulolytic genes in ascomycetes for their role as inducers in the basidiomycete white-rot fungusDichomitus squalensusing a transcriptomic approach. This identified cellobiose andl-rhamnose as the main inducers of cellulolytic and pectinolytic genes, respectively, ofD. squalens. Our results also identified differences in gene expression patterns between dikaryotic and monokaryotic strains ofD. squalenscultivated on plant biomass-derived monosaccharides and the disaccharide cellobiose. This suggests that despite conservation of the induction between these two genetic forms ofD. squalens, the fine-tuning in the gene regulation of lignocellulose conversion is differently organized in these strains.IMPORTANCEWood-decomposing basidiomycete fungi have a major role in the global carbon cycle and are promising candidates for lignocellulosic biorefinery applications. However, information on which components trigger enzyme production is currently lacking, which is crucial for the efficient use of these fungi in biotechnology. In this study, transcriptomes of the white-rot fungusDichomitus squalensfrom plant biomass-derived monosaccharide and cellobiose cultures were studied to identify compounds that induce the expression of genes involved in plant biomass degradation.

scholarly journals STRIPAK, a Key Regulator of Fungal Development, Operates as a Multifunctional Signaling Hub

2021 ◽  
Vol 7 (6) ◽  
pp. 443
Author(s):  
Ulrich Kück ◽  
Valentina Stein
Keyword(s):  
Signaling Pathways ◽  
Secondary Metabolism ◽  
Fruiting Body ◽  
Fruiting Body Formation ◽  
Vegetative Development ◽  
Fungal Development ◽  
Developmental Processes ◽  
Structural Investigations ◽  
Body Formation ◽  
Signaling Complex

The striatin-interacting phosphatases and kinases (STRIPAK) multi subunit complex is a highly conserved signaling complex that controls diverse developmental processes in higher and lower eukaryotes. In this perspective article, we summarize how STRIPAK controls diverse developmental processes in euascomycetes, such as fruiting body formation, cell fusion, sexual and vegetative development, pathogenicity, symbiosis, as well as secondary metabolism. Recent structural investigations revealed information about the assembly and stoichiometry of the complex enabling it to act as a signaling hub. Multiple organellar targeting of STRIPAK subunits suggests how this complex connects several signaling transduction pathways involved in diverse cellular developmental processes. Furthermore, recent phosphoproteomic analysis shows that STRIPAK controls the dephosphorylation of subunits from several signaling complexes. We also refer to recent findings in yeast, where the STRIPAK homologue connects conserved signaling pathways, and based on this we suggest how so far non-characterized proteins may functions as receptors connecting mitophagy with the STRIPAK signaling complex. Such lines of investigation should contribute to the overall mechanistic understanding of how STRIPAK controls development in euascomycetes and beyond.

scholarly journals Redundancy among Manganese Peroxidases in Pleurotus ostreatus

2013 ◽  
Vol 79 (7) ◽  
pp. 2405-2415 ◽  
Author(s):  
Tomer M. Salame ◽  
Doriv Knop ◽  
Dana Levinson ◽  
Oded Yarden ◽  
Yitzhak Hadar
Keyword(s):  
Gene Family ◽  
Pleurotus Ostreatus ◽  
Azo Dye ◽  
White Rot Fungi ◽  
White Rot ◽  
Orange Ii ◽  
Content Type ◽  
Affect Expression ◽  
Peptone Medium ◽  
Time Point

ABSTRACTManganese peroxidases (MnPs) are key players in the ligninolytic system of white rot fungi. InPleurotus ostreatus(the oyster mushroom) these enzymes are encoded by a gene family comprising nine members,mnp1to -9(mnpgenes). Mn2+amendment toP. ostreatuscultures results in enhanced degradation of recalcitrant compounds (such as the azo dye orange II) and lignin. In Mn2+-amended glucose-peptone medium,mnp3,mnp4, andmnp9were the most highly expressedmnpgenes. After 7 days of incubation, the time point at which the greatest capacity for orange II decolorization was observed,mnp3expression and the presence of MnP3 in the extracellular culture fluids were predominant. To determine the significance of MnP3 for ligninolytic functionality in Mn2+-sufficient cultures,mnp3was inactivated via the Δku80strain-basedP. ostreatusgene-targeting system. In Mn2+-sufficient medium, inactivation ofmnp3did not significantly affect expression of nontargeted MnPs or their genes, nor did it considerably diminish the fungal Mn2+-mediated orange II decolorization capacity, despite the significant reduction in total MnP activity. Similarly, inactivation of eithermnp4ormnp9did not affect orange II decolorization ability. These results indicate functional redundancy within theP. ostreatusMnP gene family, enabling compensation upon deficiency of one of its members.

scholarly journals Limits of Versatility of Versatile Peroxidase

2016 ◽  
Vol 82 (14) ◽  
pp. 4070-4080 ◽  
Author(s):  
Doriv Knop ◽  
Dana Levinson ◽  
Arik Makovitzki ◽  
Avi Agami ◽  
Elad Lerer ◽  
...  
Keyword(s):  
Active Site ◽  
Aromatic Compounds ◽  
Pleurotus Ostreatus ◽  
Active Sites ◽  
Oxidation Mechanism ◽  
White Rot ◽  
White Rot Fungus ◽  
Reactive Black 5 ◽  
Direct Oxidation ◽  
Content Type

ABSTRACTAlthough Mn2+is the most abundant substrate of versatile peroxidases (VPs), repression ofPleurotus ostreatusvp1expression occurred in Mn2+-sufficient medium. This seems to be a biological contradiction. The aim of this study was to explore the mechanism of direct oxidation by VP1 under Mn2+-deficient conditions, as it was found to be the predominant enzyme during fungal growth in the presence of synthetic and natural substrates. The native VP1 was purified and characterized using three substrates, Mn2+, Orange II (OII), and Reactive Black 5 (RB5), each oxidized by a different active site in the enzyme. While the pH optimum for Mn2+oxidation is 5, the optimum pH for direct oxidation of both dyes was found to be 3. Indeed, effectivein vivodecolorization occurred in media without addition of Mn2+only under acidic conditions. We have determined that Mn2+inhibitsin vitrothe direct oxidation of both OII and RB5 while RB5 stabilizes both Mn2+and OII oxidation. Furthermore, OII was found to inhibit the oxidation of both Mn2+and RB5. In addition, we could demonstrate that VP1 can cleave OII in two different modes. Under Mn2+-mediated oxidation conditions, VP1 was able to cleave the azo bond only in asymmetric mode, while under the optimum conditions for direct oxidation (absence of Mn2+at pH 3) both symmetric and asymmetric cleavages occurred. We concluded that the oxidation mechanism of aromatic compounds by VP1 is controlled by Mn2+and pH levels both in the growth medium and in the reaction mixture.IMPORTANCEVP1 is a member of the ligninolytic heme peroxidase gene family of the white rot fungusPleurotus ostreatusand plays a fundamental role in biodegradation. This enzyme exhibits a versatile nature, as it can oxidize different substrates under altered environmental conditions. VPs are highly interesting enzymes due to the fact that they contain unique active sites that are responsible for direct oxidation of various aromatic compounds, including lignin, in addition to the well-known Mn2+binding active site. This study demonstrates the limits of versatility ofP. ostreatusVP1, which harbors multiple active sites, exhibiting a broad range of enzymatic activities, but they perform differently under distinct conditions. The versatility ofP. ostreatusand its enzymes is an advantageous factor in the fungal ability to adapt to changing environments. This trait expands the possibilities for the potential utilization ofP. ostreatusand other white rot fungi.

scholarly journals The Conifer Root and Stem Rot Pathogen (Heterobasidion parviporum): Effectome Analysis and Roles in Interspecific Fungal Interactions

2019 ◽  
Vol 7 (12) ◽  
pp. 658
Author(s):  
Zilan Wen ◽  
Zhen Zeng ◽  
Fei Ren ◽  
Fred O. Asiegbu
Keyword(s):  
Expression Patterns ◽  
Physical Contact ◽  
Secreted Proteins ◽  
Stem Rot ◽  
Dual Culture ◽  
In Planta ◽  
Zone Formation ◽  
Fungal Interactions ◽  
Small Secreted Proteins

Heterobasidion parviporum Niemelä & Korhonen is an economically important basidiomycete, causing root and stem rot disease of Norway spruce (Picea abies (L.) Karst) in Northern Europe. The H. parviporum genome encodes numerous small secreted proteins, which might be of importance for interacting with mycorrhiza symbionts, endophytes, and other saprotrophs. We hypothesized that small secreted proteins from H. parviporum (HpSSPs) are involved in interspecific fungal interaction. To identify HpSSP-coding genes potentially involved, we screened the H. parviporum effectome and compared their transcriptomic profiles during fungal development and in planta tree infection. We further conducted phylogenetic analysis, and identified a subset of hypothetical proteins with nonpredicted domain or unknown function as HpSSPs candidates for further characterization. The HpSSPs candidates were selected based on high-quality sequence, cysteine residue frequency, protein size, and in planta expression. We subsequently explored their roles during in vitro interaction in paired cultures of H. parviporum with ectomycorrhizal Cortinarius gentilis, endophytic Phialocephala sphaeroides, saprotrophs (Mycena sp., Phlebiopsis gigantea, and Phanerochaete chrysosporium), respectively. The transcriptomic profile revealed that a large proportion of effector candidates was either barely expressed or highly expressed under all growth conditions. In vitro dual-culture test showed that P. sphaeroides and C. gentilis were overgrown by H. parviporum. The barrage zone formation or no physical contact observed in paired cultures with the saprotrophs suggest they had either combative interaction or antibiosis effect with H. parviporum. Several HpSSPs individuals were up- or downregulated during the nonself interactions. The results of HpSSPs gene expression patterns provide additional insights into the diverse roles of SSPs in tree infection and interspecific fungal interactions.

scholarly journals Validation of Reference Genes for Transcriptional Analyses in Pleurotus ostreatus by Using Reverse Transcription-Quantitative PCR

2015 ◽  
Vol 81 (12) ◽  
pp. 4120-4129 ◽  
Author(s):  
Raúl Castanera ◽  
Leticia López-Varas ◽  
Antonio G. Pisabarro ◽  
Lucía Ramírez
Keyword(s):  
Quantitative Pcr ◽  
Reverse Transcription ◽  
Pleurotus Ostreatus ◽  
Reference Genes ◽  
Time Course ◽  
Extracellular Enzymes ◽  
Expression Patterns ◽  
Model Organism ◽  
Culture Conditions ◽  
Content Type

ABSTRACTRecently, the lignin-degrading basidiomycetePleurotus ostreatushas become a widely used model organism for fungal genomic and transcriptomic analyses. The increasing interest in this species has led to an increasing number of studies analyzing the transcriptional regulation of multigene families that encode extracellular enzymes. Reverse transcription (RT) followed by real-time PCR is the most suitable technique for analyzing the expression of gene sets under multiple culture conditions. In this work, we tested the suitability of 13 candidate genes for their use as reference genes inP. ostreatustime course cultures for enzyme production. We applied three different statistical algorithms and obtained a combination of stable reference genes for optimal normalization of RT-quantitative PCR assays. This reference index can be used for future transcriptomic analyses and validation of transcriptome sequencing or microarray data. Moreover, we analyzed the expression patterns of a laccase and a manganese peroxidase (lacc10andmnp3, respectively) in lignocellulose and glucose-based media using submerged, semisolid, and solid-state fermentation. By testing different normalization strategies, we demonstrate that the use of nonvalidated reference genes as internal controls leads to biased results and misinterpretations of the biological responses underlying expression changes.

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