scholarly journals Omics Analyses of Trichoderma reesei CBS999.97 and QM6a Indicate the Relevance of Female Fertility to Carbohydrate-Active Enzyme and Transporter Levels

2017 ◽  
Vol 83 (22) ◽  
Author(s):  
Doris Tisch ◽  
Kyle R. Pomraning ◽  
James R. Collett ◽  
Michael Freitag ◽  
Scott E. Baker ◽  
...  
Keyword(s):  
Cell Wall ◽  
Gene Regulation ◽  
Carbon Source ◽  
Trichoderma Reesei ◽  
Plant Cell Wall ◽  
Female Fertility ◽  
Mating Types ◽  
Carbon Source Utilization ◽  
Cell Wall Degrading Enzymes ◽  
Content Type

ABSTRACT The filamentous fungus Trichoderma reesei is found predominantly in the tropics but also in more temperate regions, such as Europe, and is widely known as a producer of large amounts of plant cell wall-degrading enzymes. We sequenced the genome of the sexually competent isolate CBS999.97, which is phenotypically different from the female sterile strain QM6a but can cross sexually with QM6a. Transcriptome data for growth on cellulose showed that entire carbohydrate-active enzyme (CAZyme) families are consistently differentially regulated between these strains. We evaluated backcrossed strains of both mating types, which acquired female fertility from CBS999.97 but maintained a mostly QM6a genetic background, and we could thereby distinguish between the effects of strain background and female fertility or mating type. We found clear regulatory differences associated with female fertility and female sterility, including regulation of CAZyme and transporter genes. Analysis of carbon source utilization, transcriptomes, and secondary metabolites in these strains revealed that only a few changes in gene regulation are consistently correlated with different mating types. Different strain backgrounds (QM6a versus CBS999.97) resulted in the most significant alterations in the transcriptomes and in carbon source utilization, with decreased growth of CBS999.97 on several amino acids (for example proline or alanine), which further correlated with the downregulation of genes involved in the respective pathways. In combination, our findings support a role of fertility-associated processes in physiology and gene regulation and are of high relevance for the use of sexual crossing in combining the characteristics of two compatible strains or quantitative trait locus (QTL) analysis. IMPORTANCE Trichoderma reesei is a filamentous fungus with a high potential for secretion of plant cell wall-degrading enzymes. We sequenced the genome of the fully fertile field isolate CBS999.97 and analyzed its gene regulation characteristics in comparison with the commonly used laboratory wild-type strain QM6a, which is not female fertile. Additionally, we also evaluated fully fertile strains with genotypes very close to that of QM6a in order to distinguish between strain-specific and fertility-specific characteristics. We found that QM6a and CBS999.97 clearly differ in their growth patterns on different carbon sources, CAZyme gene regulation, and secondary metabolism. Importantly, we found altered regulation of 90 genes associated with female fertility, including CAZyme genes and transporter genes, but only minor mating type-dependent differences. Hence, when using sexual crossing in research and for strain improvement, it is important to consider female fertile and female sterile strains for comparison with QM6a and to achieve optimal performance.

scholarly journals Xylanase Gene Transcription in Trichoderma reesei Is Triggered by Different Inducers Representing Different Hemicellulosic Pentose Polymers

2013 ◽  
Vol 12 (3) ◽  
pp. 390-398 ◽  
Author(s):  
Silvia Herold ◽  
Robert Bischof ◽  
Benjamin Metz ◽  
Bernhard Seiboth ◽  
Christian P. Kubicek
Keyword(s):  
Trichoderma Reesei ◽  
Plant Cell Wall ◽  
Glycosyl Hydrolase ◽  
Xylose Reductase ◽  
Genome Mining ◽  
Transcriptional Analysis ◽  
Cell Wall Degrading Enzymes ◽  
Content Type ◽  
Knockout Mutants ◽  
Catabolite Repressor

ABSTRACTThe ascomyceteTrichoderma reeseiis a paradigm for the regulation and production of plant cell wall-degrading enzymes, including xylanases. Four xylanases, including XYN1 and XYN2 of glycosyl hydrolase family 11 (GH11), the GH10 XYN3, and the GH30 XYN4, were already described. By genome mining, we identified a fifth xylanase, XYN5, belonging to GH11. Transcriptional analysis reveals that the expression of all xylanases butxyn3is induced byd-xylose, dependent on the cellulase and xylanase regulator XYR1 and negatively regulated by the carbon catabolite repressor CRE1. Impairment ofd-xylose catabolism at thed-xylose reductase and xylitol dehydrogenase step strongly enhanced induction byd-xylose. Knockout of thel-xylulose reductase-encoding genelxr3, which connects thed-xylose andl-arabinose catabolic pathways, had no effect on xylanase induction. Besides the induction byd-xylose, theT. reeseixylanases were also induced byl-arabinose, and this induction was also enhanced in knockout mutants inl-arabinose reductase (xyl1),l-arabitol dehydrogenase (lad1), andl-xylulose reductase (lxr3). Induction byl-arabinose was also XYR1 dependent. Analysis of intracellular polyols revealed accumulation of xylitol in all strains only during incubation withd-xylose and accumulation ofl-arabitol only during incubation withl-arabinose. Induction byl-arabinose could be further stimulated by addition ofd-xylose. We conclude that the expression of theT. reeseixylanases can be induced by bothd-xylose andl-arabinose, but independently of each other and by using different inducing metabolites.

scholarly journals The Trk Potassium Transporter Is Required for RsmB-Mediated Activation of Virulence in the Phytopathogen Pectobacterium wasabiae

2015 ◽  
Vol 198 (2) ◽  
pp. 248-255 ◽  
Author(s):  
Rita S. Valente ◽  
Karina B. Xavier
Keyword(s):  
Cell Wall ◽  
Environmental Factor ◽  
Plant Cell ◽  
Plant Pathogen ◽  
Plant Cell Wall ◽  
Cell Wall Degrading Enzymes ◽  
Content Type ◽  
Regulatory Pathways ◽  
Potassium Transporter ◽  
Degrading Enzymes

ABSTRACTPectobacterium wasabiae(previously known asErwinia carotovora) is an important plant pathogen that regulates the production of plant cell wall-degrading enzymes through anN-acyl homoserine lactone-based quorum sensing system and through the GacS/GacA two-component system (also known as ExpS/ExpA). At high cell density, activation of GacS/GacA induces the expression of RsmB, a noncoding RNA that is essential for the activation of virulence in this bacterium. A genetic screen to identify regulators of RsmB revealed that mutants defective in components of a putative Trk potassium transporter (trkHandtrkA) had decreasedrsmBexpression. Further analysis of these mutants showed that changes in potassium concentration influencedrsmBexpression and consequent tissue damage in potato tubers and that this regulation required an intact Trk system. Regulation ofrsmBexpression by potassium via the Trk system occurred even in the absence of the GacS/GacA system, demonstrating that these systems act independently and are both required for full activation of RsmB and for the downstream induction of virulence in potato infection assays. Overall, our results identified potassium as an essential environmental factor regulating the Rsm system, and the consequent induction of virulence, in the plant pathogenP. wasabiae.IMPORTANCECrop losses from bacterial diseases caused by pectolytic bacteria are a major problem in agriculture. By studying the regulatory pathways involved in controlling the expression of plant cell wall-degrading enzymes inPectobacterium wasabiae, we showed that the Trk potassium transport system plays an important role in the regulation of these pathways. The data presented further identify potassium as an important environmental factor in the regulation of virulence in this plant pathogen. We showed that a reduction in virulence can be achieved by increasing the extracellular concentration of potassium. Therefore, this work highlights how elucidation of the mechanisms involved in regulating virulence can lead to the identification of environmental factors that can influence the outcome of infection.

scholarly journals Erwinia carotovora Quorum Sensing System Regulates Host-Specific Virulence Factors and Development Delay in Drosophila melanogaster

mBio ◽  
2020 ◽  
Vol 11 (3) ◽  
Author(s):  
Filipe J. D. Vieira ◽  
Pol Nadal-Jimenez ◽  
Luis Teixeira ◽  
Karina B. Xavier
Keyword(s):  
Cell Wall ◽  
Drosophila Melanogaster ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Plant Cell Wall ◽  
Erwinia Carotovora ◽  
Homoserine Lactone ◽  
Cell Wall Degrading Enzymes ◽  
Content Type ◽  
Pectolytic Enzymes

ABSTRACT Multihost bacteria have to rapidly adapt to drastic environmental changes, relying on a fine integration of multiple stimuli for an optimal genetic response. Erwinia carotovora spp. are phytopathogens that cause soft-rot disease. Strain Ecc15 in particular is a model for bacterial oral-route infection in Drosophila melanogaster as it harbors a unique gene, evf, that encodes the Erwinia virulence factor (Evf), which is a major determinant for infection of the D. melanogaster gut. However, the factors involved in the regulation of evf expression are poorly understood. We investigated whether evf could be controlled by quorum sensing as, in the Erwinia genus, quorum sensing regulates pectolytic enzymes, the major virulence factors needed to infect plants. Here, we show that transcription of evf is positively regulated by quorum sensing in Ecc15 via acyl-homoserine lactone (AHL) signal synthase ExpI and AHL receptors ExpR1 and ExpR2. We also show that the load of Ecc15 in the gut depends upon the quorum sensing-mediated regulation of evf. Furthermore, we demonstrate that larvae infected with Ecc15 suffer a developmental delay as a direct consequence of the regulation of evf via quorum sensing. Finally, we demonstrate that evf is coexpressed with plant cell wall-degrading enzymes (PCWDE) during plant infection in a quorum sensing-dependent manner. Overall, our results show that Ecc15 relies on quorum sensing to control production of both pectolytic enzymes and Evf. This regulation influences the interaction of Ecc15 with its two known hosts, indicating that quorum sensing signaling may impact bacterial dissemination via insect vectors that feed on rotting plants. IMPORTANCE Integration of genetic networks allows bacteria to rapidly adapt to changing environments. This is particularly important in bacteria that interact with multiple hosts. Erwinia carotovora is a plant pathogen that uses Drosophila melanogaster as a vector. To interact with these two hosts, Ecc15 uses different sets of virulence factors: plant cell wall-degrading enzymes to infect plants and the Erwinia virulence factor (evf) to infect Drosophila. Our work shows that, despite the virulence factors being specific for each host, both sets are coactivated by homoserine lactone quorum sensing and by the two-component GacS/A system in infected plants. This regulation is essential for Ecc15 loads in the gut of Drosophila and minimizes the developmental delay caused by the bacteria with respect to the insect vector. Our findings provide evidence that coactivation of the host-specific factors in the plant may function as a predictive mechanism to maximize the probability of transit of the bacteria between hosts.

scholarly journals Synergistic Effect of Different Plant Cell Wall–Degrading Enzymes Is Important for Virulence of Fusarium graminearum

2017 ◽  
Vol 30 (11) ◽  
pp. 886-895 ◽  
Author(s):  
Maria Chiara Paccanaro ◽  
Luca Sella ◽  
Carla Castiglioni ◽  
Francesca Giacomello ◽  
Ana Lilia Martínez-Rocha ◽  
...  
Keyword(s):  
Cell Wall ◽  
Fusarium Graminearum ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Xylanase Activity ◽  
Cellulase Activity ◽  
Wild Type ◽  
Cell Wall Degrading Enzymes ◽  
Xylanase Production ◽  
Significant Difference

Endo-polygalacturonases (PGs) and xylanases have been shown to play an important role during pathogenesis of some fungal pathogens of dicot plants, while their role in monocot pathogens is less defined. Pg1 and xyr1 genes of the wheat pathogen Fusarium graminearum encode the main PG and the major regulator of xylanase production, respectively. Single- and double-disrupted mutants for these genes were obtained to assess their contribution to fungal infection. Compared with wild-type strain, the ∆pg mutant showed a nearly abolished PG activity, slight reduced virulence on soybean seedlings, but no significant difference in disease symptoms on wheat spikes; the ∆xyr mutant was strongly reduced in xylanase activity and moderately reduced in cellulase activity but was as virulent as wild type on both soybean and wheat plants. Consequently, the ΔpgΔxyr double mutant was impaired in xylanase, PG, and cellulase activities but, differently from single mutants, was significantly reduced in virulence on both plants. These findings demonstrate that the concurrent presence of PG, xylanase, and cellulase activities is necessary for full virulence. The observation that the uronides released from wheat cell wall after a F. graminearum PG treatment were largely increased by the fungal xylanases suggests that these enzymes act synergistically in deconstructing the plant cell wall.

scholarly journals Induction of Fusarium lytic Enzymes by Extracts from Resistant and Susceptible Cultivars of Pea (Pisum sativum L.)

Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 976
Author(s):  
Lakshmipriya Perincherry ◽  
Chaima Ajmi ◽  
Souheib Oueslati ◽  
Agnieszka Waśkiewicz ◽  
Łukasz Stępień
Keyword(s):  
Cell Wall ◽  
Plant Extracts ◽  
Plant Cell Wall ◽  
Pathogenic Fungi ◽  
Human Beings ◽  
Cell Wall Degrading Enzymes ◽  
Lytic Enzymes ◽  
Mycelium Growth ◽  
Oat Bran

Being pathogenic fungi, Fusarium produce various extracellular cell wall-degrading enzymes (CWDEs) that degrade the polysaccharides in the plant cell wall. They also produce mycotoxins that contaminate grains, thereby posing a serious threat to animals and human beings. Exposure to mycotoxins occurs through ingestion of contaminated grains, inhalation and through skin absorption, thereby causing mycotoxicoses. The toxins weaken the host plant, allowing the pathogen to invade successfully, with the efficiency varying from strain to strain and depending on the plant infected. Fusariumoxysporum predominantly produces moniliformin and cyclodepsipeptides, whereas F. proliferatum produces fumonisins. The aim of the study was to understand the role of various substrates and pea plant extracts in inducing the production of CWDEs and mycotoxins. Additionally, to monitor the differences in their levels when susceptible and resistant pea plant extracts were supplemented. The cultures of F. proliferatum and F. oxysporum strains were supplemented with various potential inducers of CWDEs. During the initial days after the addition of substrates, the fungus cocultivated with pea extracts and other carbon substrates showed increased activities of β-glucosidase, xylanase, exo-1,4-glucanase and lipase. The highest inhibition of mycelium growth (57%) was found in the cultures of F. proliferatum strain PEA1 upon the addition of cv. Sokolik extract. The lowest fumonisin content was exhibited by the cultures with the pea extracts and oat bran added, and this can be related to the secondary metabolites and antioxidants present in these substrates.

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