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Injection molding of thin-walled plastic parts with minimum deformation in warpage and volume shrinkage is crucial for part quality. Simulation combined Latin hypercube sampling approach was used to research the effects of different process parameters on deformation. Then, random forest regression (RFR) is used to construct the mathematical relationship between process parameters and defects, such as warpage and volume shrinkage. The gaussian process is used as probabilistic surrogate model, while the probability of improvement is used as acquisition function to construct a Bayesian optimization for RFR’s hyperparameters, and the performance of random search is compared. In addition, the gradient boosting regression (GBR) and support vector regression (SVR) were also adopted to establish the prediction models, respectively. Comparing all the above prediction models, it can be found that the Bayesian optimized random forest regression (BO-RFR) has the highest accuracy. The Non-dominated Sorting Genetic Algorithm-II (NSGA-II) is interfaced with the predictive models to find the optimum design parameters for the purpose of effectively predicting and controlling warpage and volume shrinkage. The results show that warpage is reduced by 66.03% while volume shrinkage is 46.20% after optimizing. The final finite element simulation and physical tests indicate that this proposed method can effectively achieve the multi-objective optimization of injection molding.

Owing to the influence of the injection molding process, warpage and volume shrinkage are two common quality defects for products manufactured by glass fiber-reinforced plastic (GFRP) injection molding. To minimize these two defects, an extreme learning machine optimized with a genetic algorithm (GA-ELM), multi-objective firefly algorithm (MOFA), and a multi-objective decision-making method (GRA-TOPSIS) were implemented in this study. All of the experiments, based on Latin hypercubic sampling (LHS), were conducted using Moldflow software to obtain the results for warpage and volume shrinkage. The prediction accuracy of the defect-prediction models based on the extreme learning machine (ELM) and GA-ELM algorithms were compared. The results show that the GA-ELM models can better predict the defect values. Finally, MOFA was used to find the Pareto optimal front, and the GRA-TOPSIS method was used to find the optimum solution from the Pareto optimal front. According to the results of the simulation verification, the warpage and volume shrinkage were effectively reduced by 12.25% and 6.11%, respectively, compared with before optimization, which indicates the effectiveness and reliability of the optimization method.

In order to solve the problems of weight solving and information aggregation in the Vague multi-attribute group decision-making, this paper first solves the weight of Vague evaluation value, and then fuses the information of Vague sets through evidence theory, and obtains an information aggregation algorithm for Vague multi-attribute group decision-making. Firstly, The algorithm draws on the idea of solving the weight of evidence in the improved evidence theory algorithm, and calculates the weight of Vague evaluation value, and revises the original evaluation information after obtaining the weight of each Vague evaluation value. Secondly, this algorithm analyzes the mathematical relationship between the Vague sets and the evidence theory, and uses the evidence theory to fuse the evaluation information to obtain the final Vague evaluation value of each alternative. Finally, this algorithm uses a score function to calculate the score of each alternative to determine the best alternative. The algorithm given in the paper enables decision-makers to make rational decisions in uncertain environments, and then select the best alternative.

BackgroundCandida albicansis a commensal yeast that may cause life-threatening infections. Studies have shown that the cytochrome b-c1 complex subunit 7 gene (QCR7) ofC. albicansencodes a protein that forms a component of the mitochondrial electron transport chain complex III, making it an important target for studying the virulence of this yeast. However, to the best of our knowledge, the functions ofQCR7have not yet been characterized.MethodsAQCR7knockout strain was constructed using SN152, and BALb/c mice were used as model animals to determine the role ofQCR7in the virulence ofC. albicans. Subsequently, the effects ofQCR7on mitochondrial functions and use of carbon sources were investigated. Next, its mutant biofilm formation and hyphal growth maintenance were compared with those of the wild type. Furthermore, the transcriptome of theqcr7Δ/Δmutant was compared with that of the WT strain to explore pathogenic mechanisms.ResultsDefectiveQCR7attenuated the virulence ofC. albicansinfection in vivo. Furthermore, the mutant influenced the use of multiple alternative carbon sources that exist in several host niches. Moreover, it led to mitochondrial dysfunction. Furthermore, theQCR7knockout strain showed defects in biofilm formation or the maintenance of filamentous growth. The overexpression of cell-surface-associated genes (HWP1, YWP1, XOG1, andSAP6) can restore defective virulence phenotypes and the carbon-source utilization ofqcr7Δ/Δ.ConclusionThis study provides new insights into the mitochondria-based metabolism ofC. albicans, accounting for its virulence and the use of variable carbon sources that promoteC. albicansto colonize host niches.

The filamentous fungus Trichoderma reesei (teleomorph Hypocrea jecorina) is widely used as a cellulase producer in the industry. Herein, we describe the rational engineering of the publicly available T. reesei QM9414 strain to achieve a remarkable high-level production of cellulase on glucose. Overexpression of the key cellulase regulator XYR1 by the copper-repressible promoter Ptcu1 was first implemented to achieve a full cellulase production in the context of catabolite repression (CCR) while eliminating the requirement of inducing sugars for enzyme production. The T. reesei bgl1 gene was further overexpressed to compensate for its low β-glucosidase activity on glucose. This overexpression resulted in a 102% increase in FPase activity compared with the CCR-released RUT-C30 strain cultured on Avicel. Moreover, the saccharification efficiency toward pretreated corncob residues by crude enzymes from the engineered strain on glucose increased by 85% compared with that treated by enzymes from RUT-C30 cultivated on Avicel. The engineered T. reesei strain thus shows great potential as a viable alternative to deliver commercial cellulases after further optimization for efficient saccharification of agricultural waste.

Enzymatic hydrolysis of xylan represents a promising way to produce xylooligosaccharide (XOS), which is a novel ingredient in functional food. However, the recalcitrance of xylan in natural lignocellulosic biomass entails effective and robust xylanases. In the present study, we reported the isolation of a thermophilic Streptomyces sp. B6 from mushroom compost producing high xylanase activity. Two xylanases of Streptomyces sp. B6 belonging to GH10 (XynST10) and GH11 (XynST11) families were thus identified and biochemically characterized to be robust enzymes with high alkaline- and thermostability. Direct hydrolysis of neutralized viscose fiber production waste using XynST10 and XynST11 showed that while XynST10 produced 23.22 g/L XOS with a degree of polymerization (DP) of 2-4 and 9.27 g/L xylose, XynST11 produced much less xylose (1.19 g/L) and a higher amounts of XOS with a DP = 2-4 (28.29 g/L). Thus, XynST11 holds great potential for the production of XOS from agricultural and industrial waste.

Background Hierarchical diagnosis and treatment has been gradually implemented throughout the China. Primary physicians are the main force in primary-level medical and health services, which means that standardized training of primary-level doctors is indispensable. Objectives Evaluation of the effect of primary physician training on standardized management of diabetes, and comparison of the effects of different training models. Method The study selected 24 community health service centers from 4 cities in Liaoning Province, and consisted of two groups: primary physicians (n = 2083) who received training; and patients with diabetes (n = 585) in community health service centers. Short-term training effects on primary physicians were assessed through diabetes knowledge tests at baseline and at the end of training; the long-term effects of training on patients with diabetes were assessed by questionnaires at baseline and 1 year after training. The differences in training effects between different training models were compared. Complication screening results were also assessed. Results After training, the primary physicians’ knowledge of diabetes diagnosis and treatment improved (p p = 0.033). There were significant differences in the training effect between different training models (p = 0.038). The short-term intensive training group demonstrated the greatest training effect, primary physicians under this training model are more likely to conduct standardized screenings for patients (OR = 1.806, 95%CI 1.008–3.233), and the complication screening rate was the highest (37.6%). Conclusion This study shows that training of primary physicians is an effective way to improve the standardized management of diabetes, by improving the ability of primary physicians to manage diabetes in a standardized manner, so that patients in primary hospitals receive more comprehensive diagnosis and treatment services. Compared with scattered training throughout the year, short-term intensive training was found to be more effective.

In 2015, the State Council issued “Made in China 2025,” stating that the deep integration of information technology and manufacturing should be accelerated, and intelligent manufacturing should be the main direction of integration. In this context, China’s manufacturing-led cities have implemented the “machine substitution” program to upgrade traditional machinery and equipment to intelligent machinery and equipment, which has led to the development of traditional financial leasing models in China, such as capital. Constraints, financing channel constraints, risk constraints, and information constraints have severely constrained the advancement of the intelligent manufacturing process. In this context, the paper discusses the use of the Internet of things as a technical means to help the existing smart manufacturing enterprises to access the financing channels and open up new financing channels.

Cellulase gene expression in Trichoderma reesei is highly responsive to environmental cues and is under stringent regulation by multiple transcription factors. XYR1 (Xylanase regulator 1) has been identified as the most important transcriptional activator of cellulase/hemicellulase gene expression although the precise transactivating mechanism remains largely elusive. Here we show that the activation domain of XYR1 interacts with the T. reesei homolog of the TrSNF12 subunit of SWI/SNF complex. Deletion of Trsnf12 markedly impaired the induced cellulase gene expression. Individual loss of other SWI/SNF subunits including the catalytic subunit also severely compromised cellulase gene expression and interfered with loss of histone H4 in the cbh1 and eg1 promoters upon cellulose induction. In addition, we find that the SWI/SNF occupancy on cellulase gene promoters strictly required XYR1 and TrSNF12 but TrSNF12 was dispensable for the XYR1 binding to these promoters. These data suggest a model in which XYR1 recruits SWI/SNF through direct interactions with TrSNF12 to remodel chromatin at cellulase gene promoters, thereby activating cellulase gene expression to initiate the cellulolytic response in T. reesei.

The miR396/target module affects juvenile to adult transition and flowering in Arabidopsis. The spatio-temporal distribution of miR396 during leaf development, which helps to control leaf shape and modify phase change, is regulated by SWR1-C., In this study, we investigated the regulatory function of miR396 in the phase transition in Arabidopsis thaliana. Using AtMIR396a/b knockout mutants generated through clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9)-directed genome editing, we showed that miR396 negatively regulates the leaf size and vegetative phase transition, and the first leaf with abaxial trichomes appeared earlier in the mir396ab double mutant than in the wild type (WT) and was significantly delayed in miR396 overexpression lines. Moreover, mir396ab exhibited early flowering, whereas 35S:MIR396a/b and cib4-1 delayed flowering, and the flowering time was negatively correlated with FT gene expression. Furthermore, in arp6 and pie1 mutants, which are deficient in the ATP-dependent chromatin remodeling complex (SWR1-C), miR396 expression was significantly repressed. Compared with the WT, reduced H2A.Z deposit and stronger relative nucleosome occupancy in the promoter region of MIR396a was found in the arp6 mutant, indicating that SWR1-C contributes to the transcriptional activation of MIR396a via nucleosome dynamics. In addition, miR396 displayed specific spatio-temporal expression patterns in the leaf, which was altered in arp6 and pie1, and therefore affected the transcript levels of CIB4 and FT in these mutants. We propose that miR396 is not only a marker of cell differentiation, but also an age signal for leaf development and phase change. Meanwhile, SWR1-C-mediated epigenetic regulation contributes to the age-dependent enhancement of miR396 expression and differential miR396 accumulation among leaves.

Nucleosome binding protein 1 (NSBP1) is identified as a new member of HMGN family and is abnormally overexpressed in a variety of tumors. However, it remains unclear whether NSBP1 is overexpressed and promotes gastric cancer. In this study we employed RNAi mediated knockdown of NSBP1 to investigate potential oncogenic role of NSBP1 in gastric cancer. In BGC823 and SGC7901 gastric cancer cell lines, we showed that NSBP1 knockdown decreased cell proliferation while increased apoptosis in vitro. Western blot analysis showed that NSBP1 knockdown decreased the levels of anti-apoptotic protein Bcl-2 while increased the levels of pro-apoptotic protein Bax. In addition, NSBP1 knockdown inhibited the growth and increased the apoptosis of SGC7901 cells xenografted in nude mice. In conclusion, this study provides the first evidence that NSBP1 enhances the proliferation while inhibits the apoptosis of gastric cancer cells, and this is related to the regulation of the expression of apoptosis related proteins by NSBP1. These data suggest that NSBP1 plays oncogenic role in gastric cancer.

Background Myocardial ischemia (MI) often causes angina, arrhythmia, and cardiac insufficiency, sometimes resulting in death. Ischemia-induced myocardial tissue damage is attributed to the hypoxic damage of myocardial cells producing apoptosis and decreased proliferation. Taurine has been shown to improve MI, but its mechanism is largely unknown. Methods In this study, the relationship between taurine and severity of MI in vivo was evaluated by quantifying myocardial infarct areas and metabolic indicators of myocardial damage and measuring taurine levels in cardiac muscle and plasma by high performance liquid chromatography (HPLC). To elucidate how taurine might suppress ischemic injury, we established an in vitro ischemia model with isolated primary rat cardiomyocytes cultured without serum or glucose and under hypoxia. We evaluated the indicators of MI and damage, including lactic dehydrogenase (LDH), creatine kinase (CK), and cardiac troponin I (cTnI). We also examined the levels of taurine transporter (TauT), cysteine dioxygenase (CDO), and cysteine sulfinate decarboxylase (CSD) proteins involved in transport and synthesis of taurine in the myocardium and those of 2 apoptosis-associated proteins, namely, Bcl-2 associated X protein (BAX) and B-cell lymphoma-2 (Bcl-2). Results Exposure of myocardial cells to ischemia led to the decrease of taurine content, the suppression of cell proliferation, and led to calcium ion overload and apoptosis. Pretreatment with taurine alleviated the ischemic damage, with concomitant elevation of intracellular taurine concentrations. Molecular mechanism analysis showed that pretreatment with taurine upregulated the TauT, CDO, and CSD, 2 rate-limiting enzymes involved in taurine synthesis. These effects facilitated both taurine transport into cells and taurine synthesis, leading to taurine accumulation. In addition, apoptosis inhibition by taurine appeared to be mediated by upregulated Bcl-2 and downregulated BAX, as well as inhibition of calcium overload by suppression of calcium binding protein. Conclusions We demonstrated that TauT is critical for the attenuation of myocardial ischemic damage by taurine, facilitating taurine absorption and synthesis. These findings provided new insights and a theoretical foundation for future studies examining taurine as a potential treatment for MI.

The filamentous fungus

EGCG is a major pharmacological compound in green tea. Nonalcoholic fatty liver disease (NAFLD) is one of the most common liver diseases worldwide. Inflammation and insulin resistance are involved in the development of the disease. In this study, we investigated the beneficial effect of EGCG on the liver tissue of NAFLD rats induced by a high-fat diet and its underlying mechanism. Thirty Sprague-Dawley rats received a normal diet, a HFD and a HFD+EGCG. The expression levels of inflammatory signaling pathway genes (e.g., TLR4, TRAF6, IKKβ, NF-κB, TNF-α) and insulin signaling transduction pathway genes (e.g., PI3K, AKT, IRS-1, IRS-2) were detected in the liver. We observed that EGCG decreased the triglyceride (TG) concentration in rat livers and suppressed TLR4, TRAF6, IKKβ, p-IKKβ, p-NF-κB, and TNF-α levels compared with those in the HFD group, whereas PI3K, AKT, IRS-1, and IRS-2 indicators were improved. EGCG improves obesity-associated subacute hepatic inflammation states, probably through the TLR4 signaling pathway. Furthermore, EGCG also alleviated hepatic insulin resistance. These data indicate that EGCG improves NAFLD from two ways: inhibition of inflammation and improvement of insulin resistance in liver tissues.

Enzymatic hydrolysis of xylan represents a promising way to produce xylooligosaccharide (XOS), which is a novel ingredient in functional food. However, the recalcitrance of xylan in natural lignocellulosic biomass entails effective and robust xylanases. In the present study, we reported the isolation of a thermophilic

Epigallocatechin-3-gallate (EGCG), a major active ingredient in green tea, has various health benefits. It affects glucose metabolism, but the mechanism is not well understood. This study aimed to identify targets of EGCG related to glucose metabolism. The core fragment of EGCG is a flavonoid. The flavonoid scaffold was used as a substructure to find proteins cocrystallized with flavonoids in the Protein Data Bank. The proteins identified were screened in PubMed for known relationships with diabetes. Dipeptidyl peptidase-4 (DPP4; PDB 5J3J) was identified following this approach. By molecular docking, the interactions of EGCG and DPP4 were assessed. To test the stability of the interactions between EGCG and DPP4, molecular dynamics simulation for 100 ns was performed using Desmond software. In vitro, the concentration of EGCG required to inhibit DPP4 activity by 50% (the IC50 value) was 28.42 μM. These data provide a theoretical basis for intervention in glucose metabolism with EGCG.

Cellulase gene expression in the model cellulolytic fungus Trichoderma reesei is supposed to be controlled by an intricate regulatory network involving multiple transcription factors. Here, we identified a novel transcriptional repressor of cellulase gene expression, Rce1. Disruption of the rce1 gene not only facilitated the induced expression of cellulase genes but also led to a significant delay in terminating the induction process. However, Rce1 did not participate in Cre1-mediated catabolite repression. Electrophoretic mobility shift (EMSA) and DNase I footprinting assays in combination with chromatin immunoprecipitation (ChIP) demonstrated that Rce1 could bind directly to a cbh1 (cellobiohydrolase 1-encoding) gene promoter region containing a cluster of Xyr1 binding sites. Furthermore, competitive binding assays revealed that Rce1 antagonized Xyr1 from binding to the cbh1 promoter. These results indicate that intricate interactions exist between a variety of transcription factors to ensure tight and energy-efficient regulation of cellulase gene expression in T. reesei. This study also provides important clues regarding increased cellulase production in T. reesei.

Glucose transporters mediate the intracellular uptake of glucose and play important roles in glucose metabolism and signaling. Our understanding of the structural basis for a variety of glucose transporters is, however, still limited. In this study, we presented that the glucose transporter Hgt-1, obtained from the filamentous fungus Neurospora crassa, exhibited much higher glucose transport activity than the other sugar transporter Stp1, obtained from Trichoderma reesei, although they shared high sequence identity of 75.9%. To identify the structural determinants for differential glucose transport capability displayed by Stp1 and Hgt-1, segment swapping was performed by replacing specific sequence regions of Stp1 with the corresponding sequences of Hgt-1. Investigation of the glucose transport capability of the resulting chimeric transporters revealed that replacement of a N- or a C-terminal segment of Stp1, located on the intracellular side, with that of Hgt-1 can apparently improve its transport capability. The combined swapping of these two segments further enhanced the transport capability of Stp1 to a level almost comparable to that of Hgt-1. However, deletion of the C-terminal 32 residues abolished the transport capability of Stp1, whereas deletion of the C-terminal 16 residues apparently improved its transport capability. These results provide insight into the roles of intracellular N- and C-termini of glucose transporters in glucose transport.

Alkylpyrazines are important contributors to the flavor of traditional fermented foods. Here, we studied the synthesis mechanisms of 2,5-dimethylpyrazine (2,5-DMP) and 2,3,5-trimethylpyrazine (TMP). Substrate addition, whole-cell catalysis, stable isotope tracing experiments, and gene manipulation revealed that l-threonine is the starting point involving l-threonine-3-dehydrogenase (TDH) and three uncatalyzed reactions to form 2,5-DMP. TDH catalyzes the oxidation of l-threonine. The product of this reaction is l-2-amino-acetoacetate, which is known to be unstable and can decarboxylate to form aminoacetone. It is proposed that aminoacetone spontaneously converts to 2,5-DMP in a pH-dependent reaction, via 3,6-dihydro-2,5-DMP. 2-Amino-3-ketobutyrate coenzyme A (CoA) ligase (KBL) catalyzes the cleavage of l-2-amino-acetoacetate, the product of TDH, into glycine and acetyl-CoA in the presence of CoA. Inactivation of KBL could improve the production of 2,5-DMP. Besides 2,5-DMP, TMP can also be generated by Bacillus subtilis 168 by using l-threonine and d-glucose as the substrates and TDH as the catalytic enzyme. IMPORTANCE Despite alkylpyrazines' contribution to flavor and their commercial value, the synthesis mechanisms of alkylpyrazines by microorganisms remain poorly understood. This study revealed the substrate, intermediates, and related enzymes for the synthesis of 2,5-dimethylpyrazine (2,5-DMP), which differ from the previous reports about the synthesis of 2,3,5,6-tetramethylpyrazine (TTMP). The synthesis mechanism described here can also explain the production of 2,3,5-trimethylpyrazine (TMP). The results provide insights into an alkylpyrazine’s synthesis pathway involving l-threonine-3-dehydrogenase as the catalytic enzyme and l-threonine as the substrate.

The stringent regulatory network of cellulase gene expression in the filamentous fungus Trichoderma reesei involves multiple transcriptional regulators. However, identification and mechanistic investigation of these regulators are still insufficient. Here, we identified a novel transcriptional regulator, CLP1, a plant homeo domain (PHD) Protein that participates in regulating T. reesei cellulase gene expression. Phylogenetic analyses demonstrated that CLP1 homologs are widely distributed in filamentous fungi including Trichoderma, Penicillium, Fusarium, Neurospora, and Aspergillus species. We demonstrated that CLP1 is a nuclear protein and lack of CLP1 significantly impaired the induced expression of cellulase genes. ChIP experiments showed CLP1 binding to the cellulase gene promoters specifically under cellulose conditions and compromised XYR1 occupancy on the same promoters in the absence of CLP1 at the early induction stage. XYR1 overexpression fully rescued the defect in cellulase production but not the defect in conidia formation in the clp1 null mutant. Further analysis showed that the PHD is required for the CLP1 appropriate subcellular localization as well as the induced cellulase gene expression and conidiation. Taken together, these data demonstrated an important role of CLP1 in the regulation of cellulase and xylanase gene expression in T. reesei.

Melanogenesis is the process for the production of melanin, which is the primary cause of human skin pigmentation. Skin-whitening agents are commercially available for those who wish to have a lighter skin complexions. To date, although numerous natural compounds have been proposed to alleviate hyperpigmentation, insufficient attention has been focused on potential natural skin-whitening agents and their mechanism of action from the perspective of compound classification. In the present article, the synthetic process of melanogenesis and associated core signaling pathways are summarized. An overview of the list of natural skin-lightening agents, along with their compound classifications, is also presented, where their efficacy based on their respective mechanisms of action on melanogenesis is discussed.

Positron emission tomography (PET) radiopharmaceuticals can noninvasively measure free fatty acid (FFA) uptake into adipose tissue. We studied 29 volunteers to test whether abdominal and femoral subcutaneous adipose tissue FFA uptake measured using [1-11C]palmitate PET agrees with FFA storage rates measured using an intravenous bolus of [1-14C]palmitate and adipose biopsies. The dynamic left ventricular cavity PET images combined with blood sample radioactivity corrected for the 11CO2 content were used to create the blood time activity curve (TAC), and the constant ( Ki) was determined using Patlak analysis of the TACs generated for regions of interest in abdominal subcutaneous fat. These data were used to calculate palmitate uptake rates in abdominal subcutaneous adipose tissue (µmol·kg−1·min−1). Immediately after the dynamic imaging, a static image of the thigh was taken to measure the standardized uptake value (SUV) in thigh adipose tissue, which was scaled to each participant’s abdominal adipose tissue SUV to calculate thigh adipose palmitate uptake rates. Abdominal adipose palmitate uptake using PET [1-11C]palmitate was correlated with, but significantly ( P < 0.001) greater than, FFA storage measured using [1-14C]palmitate and adipose biopsy. Thigh adipose palmitate measured using PET calculation was positively correlated ( R2 = 0.44, P < 0.0001) with and not different from the biopsy approach. The relative differences between PET measured abdominal subcutaneous adipose tissue palmitate uptake and biopsy-measured palmitate storage were positively correlated ( P = 0.03) with abdominal subcutaneous fat. We conclude that abdominal adipose tissue FFA uptake measured using PET does not equate to adipose FFA storage measured using biopsy techniques.

XYR1 is the key transcription activator for cellulase gene expression in the model filamentous fungus Trichoderma reesei, which is widely applied in the industry due to its excellent capability of secreting a large quantity of cellulases. Despite the essential role of XYR1, the regulation of its expression in T. reesei cellulolytic response is poorly understood. In this study, we identified a transcription factor RXE1 exhibiting strong binding activity to the xyr1 promoter using yeast one-hybrid screen. RXE1 homologs exist in quite a few filamentous fungi but none of them have been assessed regarding their functional involvement in plant cell wall degradation. Knockdown of rxe1 in T. reesei using a copper-mediated RNAi system not only abrogated conidiation, but also remarkably compromised xyr1 and cellulase gene expression. The defective cellulase but not conidia production in the rxe1-knockdown strain was fully rescued by the constitutive expression of XYR1. Our study thus identified a novel transcriptional regulator controlling xyr1 and cellulase gene expression, which will contribute to elaborating the intricate network of cellulase gene regulation in T. reesei.

Trichoderma reesei represents an important workhorse for industrial production of cellulases as well as other proteins. The molecular mechanism underlying the regulation of cellulase production as well as other physiological processes in T. reesei is still insufficiently understood. We constructed a P tcu1 -based promoter substitution cassette that allowed one-step replacement of the endogenous promoter for controlling the target gene expression with copper. We then showed that copper repression of the histone acetyltransferase gene gcn5 phenocopied the gcn5 deletion strain. Using the same strategy, we further characterized the function of another putative Spt-Ada-Gcn5 acetyltransferase (SAGA) complex subunit encoding gene, ada2, in T. reesei. Similar to the repression of gcn5, the addition of copper to the P tcu1 -ada2 strain not only drastically reduced the vegetative growth and conidiation in T. reesei but also severely compromised the induced cellulase gene expression. The developed strategy will thus be potentially useful to probe the biological function of the large fraction of T. reesei genes with unknown functions including those essential genes in the genome to expand its extraordinary biotechnological potential.

The ascomycete Trichoderma reesei is a highly prolific cellulase producer. While XYR1 (Xylanase regulator 1) has been firmly established to be the master activator of cellulase gene expression in T. reesei, its precise transcriptional activation mechanism remains poorly understood. In the present study, TrGAL11, a component of the Mediator tail module, was identified as a putative interacting partner of XYR1. Deletion of Trgal11 markedly impaired the induced expression of most (hemi)cellulase genes, but not that of the major β-glucosidase encoding genes. This differential involvement of TrGAL11 in the full induction of cellulase genes was reflected by the RNA polymerase II (Pol II) recruitment on their core promoters, indicating that TrGAL11 was required for the efficient transcriptional initiation of the majority of cellulase genes. In addition, we found that TrGAL11 recruitment to cellulase gene promoters largely occurred in an XYR1-dependent manner. Although xyr1 expression was significantly tuned down without TrGAL11, the binding of XYR1 to cellulase gene promoters did not entail TrGAL11. These results indicate that TrGAL11 represents a direct in vivo target of XYR1 and may play a critical role in contributing to Mediator and the following RNA Pol II recruitment to ensure the induced cellulase gene expression., Author summary As a model cellulolytic fungus, T. reesei is capable of rapidly producing a large quantity of (hemi)cellulases when appropriate substrates are present. This outstanding characteristic has made T. reesei a prominent producer of cellulase in industry and also a model organism for studying eukaryotic gene expression. The expression of these hydrolytic enzymes encoding genes in T. reesei is precisely regulated at a transcriptional level and controlled by a suite of transcription factors. Among others, the transcription activator XYR1 has been firmly established to be absolutely necessary for activating the expression of almost all cellulase genes. However, the precise mechanism it acts remains largely unknown. In eukaryotes, the multisubunit Mediator complex has been shown to be critical for expression of most, if not all, protein-coding genes by conveying regulatory information to the basal transcription machinery. Here, we find that XYR1 interacts with the Mediator tail module subunit, TrGAL11, which contributes to cellobiohydrolase (cbh) and endoglucanase (eg) genes but not β-glucosidase (bgl) genes expression. Thus, the induced XYR1 binding to cellulase gene promoters led to TrGAL11 and RNA Pol II recruitment to these promoters. These results show that TrGAL11 represents a direct in vivo target of XYR1 and provide evidence for not only the evolutionarily conserved function of Mediator, but also for the existence of some subtle difference in its action to mediate gene expression in different eukaryotes.

This paper uses the coupled synchronization control method to study the chaotic synchronization problem of fractional calculus financial systems. Firstly, the paper couples the control variables to each equation of the fractional financial system to synchronize the drive system and the response system. Secondly, the coupled control variables are added to each equation to synchronize the response system of the financial system. At the end of the thesis, the Laplace transform theory is used to prove the effectiveness of the method used in this paper.