Multifunctional MOF: Cold/hot adapted sustainable oxidase-like MOF nanozyme with ratiometric and color tonality for nitrite ions detection.

Integrating multiple functionalities into a single entity is highly important, especially when a broad spectrum of application is required. In the present work, we synthesized a novel manganese-based MOF (denoted as UoZ-6) that functions as a cold/hot-adapted and recyclable oxidase nanozyme (Km 0.085 mM) further developed for ratiometric-based colorimetric and color tonality visual-mode detection of nitrite in water and food. Nitrite ions promote the diazotization process of the oxTMB product, resulting in a decay in the absorbance signal at 652 nm and the emergence of a new signal at 461 nm. The dual-absorbance ratiometric platform for nitrite ion detection functions effectively across a wide temperature range (0 °C to 100 °C), offering a linear detection range of 5-45 µM with a detection limit of 0.15 µM using visual-mode. This approach is sensitive, reliable, and selective, making it effective for detecting nitrite ions in processed meat and water.

Multi-omics analysis revealed the mechanism underlying flavonol biosynthesis during petal color formation in Camellia Nitidissima.

BACKGROUND: Camellia nitidissima is a rare, prized camellia species with golden-yellow flowers. It has a high ornamental, medicinal, and economic value. Previous studies have shown substantial flavonol accumulation in C. nitidissima petals during flower formation. However, the mechanisms underlying the golden flower formation in C. nitidissima remain largely unknown. RESULTS: We performed an integrative analysis of the transcriptome, proteome, and metabolome of the petals at five flower developmental stages to construct the regulatory network underlying golden flower formation in C. nitidissima. Metabolome analysis revealed the presence of 323 flavonoids, and two flavonols, quercetin glycosides and kaempferol glycosides, were highly accumulated in the golden petals. Transcriptome and proteome sequencing suggested that the flavonol biosynthesis-related genes and proteins upregulated and the anthocyanin and proanthocyanidin biosynthesis-related genes and proteins downregulated in the golden petal stage. Further investigation revealed the involvement of MYBs and bHLHs in flavonoid biosynthesis. Expression analysis showed that flavonol synthase 2 (CnFLS2) was highly expressed in the petals, and its expression positively correlated with flavonol content at all flower developmental stages. Transient overexpression of CnFLS2 in the petals increased flavonol content. Furthermore, correlation analysis showed that the jasmonate (JA) pathways positively correlated with flavonol biosynthesis, and exogenous methyl jasmonate (MeJA) treatment promoted CnFLS2 expression and flavonol accumulation. CONCLUSIONS: Our findings showed that the JA-CnFLS2 module regulates flavonol biosynthesis during golden petal formation in C. nitidissima.

PGC-based cryobanking, regeneration through germline chimera mating, and CRISPR/Cas9-mediated TYRP1 modification in indigenous Chinese chickens.

Primordial germ cells (PGCs) are vital for producing sperm and eggs and are crucial for conserving chicken germplasm and creating genetically modified chickens. However, efforts to use PGCs for preserving native chicken germplasm and genetic modification via CRISPR/Cas9 are limited. Here we show that we established 289 PGC lines from eight Chinese chicken populations with an 81.6% success rate. We regenerated Piao chickens by repropagating cryopreserved PGCs and transplanting them into recipient chickens, achieving a 12.7% efficiency rate. These regenerated chickens carried mitochondrial DNA from female donor PGC and the rumplessness mutation from both male and female donors. Additionally, we created the TYRP1 (tyrosinase-related protein 1) knockout (KO) PGC lines via CRISPR/Cas9. Transplanting KO cells into male recipients and mating them with wild-type hens produced four TYRP1 KO chickens with brown plumage due to reduced eumelanin production. Our work demonstrates efficient PGC culture, cryopreservation, regeneration, and gene editing in chickens.

Exploring Evolutionary Pathways and Abiotic Stress Responses through Genome-Wide Identification and Analysis of the Alternative Oxidase (AOX) Gene Family in Common Oat (Avena sativa).

The alternative oxidase (AOX), a common terminal oxidase in the electron transfer chain (ETC) of plants, plays a crucial role in stress resilience and plant growth and development. Oat (Avena sativa), an important crop with high nutritional value, has not been comprehensively studied regarding the AsAOX gene family. Therefore, this study explored the responses and potential functions of the AsAOX gene family to various abiotic stresses and their potential evolutionary pathways. Additionally, we conducted a genome-wide analysis to explore the evolutionary conservation and divergence of AOX gene families among three Avena species (Avena sativa, Avena insularis, Avena longiglumis) and four Poaceae species (Avena sativa, Oryza sativa, Triticum aestivum, and Brachypodium distachyon). We identified 12 AsAOX, 9 AiAOX, and 4 AlAOX gene family members. Phylogenetic, motif, domain, gene structure, and selective pressure analyses revealed that most AsAOXs, AiAOXs, and AlAOXs are evolutionarily conserved. We also identified 16 AsAOX segmental duplication pairs, suggesting that segmental duplication may have contributed to the expansion of the AsAOX gene family, potentially preserving these genes through subfunctionalization. Chromosome polyploidization, gene structural variations, and gene fragment recombination likely contributed to the evolution and expansion of the AsAOX gene family as well. Additionally, we hypothesize that AsAOX2 may have potential function in resisting wounding and heat stresses, while AsAOX4 could be specifically involved in mitigating wounding stress. AsAOX11 might contribute to resistance against chromium and waterlogging stresses. AsAOX8 may have potential fuction in mitigating ABA-mediated stress. AsAOX12 and AsAOX5 are most likely to have potential function in mitigating salt and drought stresses, respectively. This study elucidates the potential evolutionary pathways of the AsAOXs gene family, explores their responses and potential functions to various abiotic stresses, identifies potential candidate genes for future functional studies, and facilitates molecular breeding applications in A. sativa.

Carbon dots based AuAg@AuNPs with oxidase-like activity for SERS dual-readouts detection of D-penicillamine.

An oxidase (OXD) -like AuAg@AuNPs nanozyme was prepared by Au seeds growth using dopamine carbon dots as reducing and capping agents. The AuAg@AuNPs show excellent OXD-like and surface-enhanced Raman spectroscopy (SERS) activities and can oxidize the non-Raman-active leucomalachite green (LMG) into the Raman-active malachite green (MG). The research displays that D-penicillamine (D-PA) can effectively inhibit the OXD-like activity of Au@AgNPs and enhance the SERS signals as substrate. It is attributed to the formation of S-Au bond due to thiol (-SH) in D-PA. Therefore, a highly sensitive and specific SERS dual-readout sensing platform was proposed to assay D-PA with a limit of detection of 0.1 µg/mL (direct SERS mode) and 6.64 µg/L (indirect SERS mode). This approach was successfully used to determine D-PA in actual pharmaceutical formulations.

Diagnostic Accuracy of FluoroCycler XT MTBDR Assay for Detection of Rifampicin and Isoniazid-resistant Mycobacteria tuberculosis in Clinical Isolates from Kenya.

BACKGROUND: Drug-resistant tuberculosis (DR-TB) poses a major global challenge to public health and therapeutics. It is an emerging global concern associated with increased morbidity and mortality mostly seen in the low- and middle-income countries. Molecular techniques are highly sensitive and offer timely and accurate results for TB drug resistance testing, thereby positively influencing patient management plan. METHODS: The study was carried out at the National Tuberculosis Reference Laboratory (NTRL) in Kenya in the period between January and October 2022. A total of 243 Mycobacterium tuberculosis (M.tb) clinical isolates were included in the study. These isolates comprised of 50 isolates with mutations in rpoB, 51 isolates with katG mutations, 51 isolates with mutations in inhA, and 91 M.tb isolates lacking mutations in these genes based on Genotype MTBDRplus results. DNA from the isolates was extracted using the FluoroLyse extraction kit. Real-time polymerase chain reaction targeting the rpoB, InhA, and katG genes was performed using the FluoroType MTBDR amplification mix. Isolates with discordant results between Genotype MTBDRplus and FluoroCycler® MTBDR assays underwent targeted sequencing for the respective genes, then, sequences were analyzed for mutations using Geneious version 11.0 software. RESULTS: The sensitivity of the Fluorocycler XT MTBDR assay for the detection of mutations that confer drug resistance was 86% (95% confidence interval [CI] 73.0-94.0) for rpoB, 96% (95% CI 87-100) for katG and 92% (95% CI 81-98) for inhA. The assay's specificity was 97% (95% CI 93-99) for rpoB, 98% (95% CI 96-100) for katG, and 97% (95% CI 93-99) for inhA. CONCLUSION: The diagnostic accuracy of FluoroType MTBDR for the detection of mutations conferring resistance to rifampicin and isoniazid was high compared with that of Genotype MTBDRplus and demonstrates its suitability as a replacement assay for Genotype MTBDRplus.

Detection of katG, inhA and ahpC gene mutation in clinical isolates of isoniazid-resistant Mycobacterium tuberculosis in Makassar City, South Sulawesi, Indonesia.

BACKGROUND: Tuberculosis (TB) is an airborne disease caused by Mycobacterium tuberculosis (M. tuberculosis). The world is currently facing challenges due to the spread of anti-tuberculosis drug-resistant of M. tuberculosis. Isoniazid-resistant (INH), is one of the first-line anti-tuberculosis agents that has a high resistance case. This study used Multiplex allele-specific Polymerase Chain Reaction (MAS-PCR) to detect the most common mutations associated with isoniazid resistance on inhA, katG, and ahpC gene. METHODS: This study used samples from clinical isolates of M. tuberculosis which had been tested for their antibiotic sensitivity of first-line anti-tuberculosis drugs. The DNA extraction process was carried out using the boiling method and then amplified with specific primers for inhA, katG, and ahpC genes using the MAS-PCR method. The results are then read on the electrophoretic gel with an interpretation of the mutation gene when the target gene DNA bands were absent according to the allele-specific fragments target. RESULTS: A total of 200 isolates were tested in this study consisting of isoniazid-resistant and susceptible with the largest distribution of Multi-Drug Resistant (MDR) isolates with a total of 146 isolates (73%). The most significant gene mutation was on the ahpC gene in 61 isolates (30,5%) and the combination mutation of the katG + ahpC gene in 52 isolates (26%) with sensitivity and specificity of the test reaching 87% and 42% for the detection of INH-resistant. CONCLUSION: Mutation on the ahpC gene has the highest percentage in this study. AhpC gene can be considered one of the essential genes to be tested for the cause of isoniazid-resistant. Using MAS-PCR for detecting gene mutation in isoniazid-resistant was simple and easy, it has the potential to be widely used as a rapid screening molecular test.

Engineered Imine Reductase Catalyzed Enantiodivergent Synthesis of Alkylated Amphetamines.

Less steric ketones exhibited low stereoselectivity toward M5 due to their difficulty in restricting the free rotation of the imine intermediate. An engineered enantio-complementary imine reductase from M5 was obtained with catalytic activity. We identified four key residues that play essential roles in controlling stereoselectivity. Two mutants, I149Y-W234L (up to 99%S ee) and L200M-F260M (up to 99%R ee), were achieved, showing excellent stereoselectivity toward the tested substrates, offering valuable biocatalysts for synthesizing alkylated amphetamines.

Long-term effect of phenol, quinoline, and pyridine on nitrite accumulation in the nitrification process: performance, microbial community, metagenomics and molecular docking analysis.

Phenol, quinoline, and pyridine, commonly found in industrial wastewater, disrupt the nitrification process, leading to nitrite accumulation. This study explores the potential mechanisms through which these biotoxic organic compounds affect nitrite accumulation, using metagenomic and molecular docking analyses. Despite increasing concentrations of these compounds from 40 to 160 mg/L, ammonia nitrogen removal was not hindered, and stable nitrite accumulation rates exceeding 90 % were maintained. Additionally, these compounds inhibited nitrite-oxidizing bacteria (NOB) and enriched ammonia-oxidizing bacteria (AOB) in situ. As the concentration of these compounds rose, protein (PN) and polysaccharide (PS) concentrations also increased, along with a higher PN/PS ratio. Metagenomic analysis further revealed an increase in hao relative abundance, while microbial community analysis showed increased Nitrosomonas abundance, which contributed to nitrite accumulation stability. Molecular docking indicated that these compounds have lower binding energy with hydroxylamine oxidoreductase (HAO) and nitrate reductase (NAR), theoretically supporting the observed sustained nitrite accumulation.

Equilibrium dialysis with HPLC detection to measure substrate binding affinity of a non-heme iron halogenase.

Determination of substrate binding affinity (Kd) is critical to understanding enzyme function. An extensive number of methods have been developed and employed to study ligand/substrate binding, but the best approach depends greatly on the substrate and the enzyme in question. Below we describe how to measure the Kd of BesD, a non-heme iron halogenase, for its native substrate lysine using equilibrium dialysis coupled with High Performance Liquid Chromatography (HPLC) for subsequent detection. This method can be performed in anaerobic glove bag settings. It requires readily available HPLC instrumentation for ligand quantitation and is adaptable to meet the needs of a variety of substrate affinity measurements.

Preparation of reductases for multicomponent oxygenases.

Oxygenases catalyze crucial reactions throughout all domains of life, cleaving molecular oxygen (O2) and inserting one or two of its atoms into organic substrates. Many oxygenases, including those in the cytochrome P450 (P450) and Rieske oxygenase enzyme families, function as multicomponent systems, which require one or more redox partners to transfer electrons to the catalytic center. As the identity of the reductase can change the reactivity of the oxygenase, characterization of the latter with its cognate redox partners is critical. However, the isolation of the native redox partner or partners is often challenging. Here, we report the preparation and characterization of PbdB, the native reductase partner of PbdA, a bacterial P450 enzyme that catalyzes the O-demethylation of para-methoxylated benzoates. Through production in a rhodoccocal host, codon optimization, and anaerobic purification, this procedure overcomes conventional challenges in redox partner production and allows for robust oxygenase characterization with its native redox partner. Key lessons learned here, including the value of production in a related host and rare codon effects are applicable to a broad range of Fe-dependent oxygenases and their components.

Mitochondria dysfunction is one of the causes of diclofenac toxicity in the green alga Chlamydomonas reinhardtii.

Background: Non-steroidal anti-inflammatory drugs (NSAIDs), such as diclofenac (DCF), form a significant group of environmental contaminants. When the toxic effects of DCF on plants are analyzed, authors often focus on photosynthesis, while mitochondrial respiration is usually overlooked. Therefore, an in vivo investigation of plant mitochondria functioning under DCF treatment is needed. In the present work, we decided to use the green alga Chlamydomonas reinhardtii as a model organism. Methods: Synchronous cultures of Chlamydomonas reinhardtii strain CC-1690 were treated with DCF at a concentration of 135.5 mg × L-1, corresponding to the toxicological value EC50/24. To assess the effects of short-term exposure to DCF on mitochondrial activity, oxygen consumption rate, mitochondrial membrane potential (MMP) and mitochondrial reactive oxygen species (mtROS) production were analyzed. To inhibit cytochrome c oxidase or alternative oxidase activity, potassium cyanide (KCN) or salicylhydroxamic acid (SHAM) were used, respectively. Moreover, the cell's structure organization was analyzed using confocal microscopy and transmission electron microscopy. Results: The results indicate that short-term exposure to DCF leads to an increase in oxygen consumption rate, accompanied by low MMP and reduced mtROS production by the cells in the treated populations as compared to control ones. These observations suggest an uncoupling of oxidative phosphorylation due to the disruption of mitochondrial membranes, which is consistent with the malformations in mitochondrial structures observed in electron micrographs, such as elongation, irregular forms, and degraded cristae, potentially indicating mitochondrial swelling or hyper-fission. The assumption about non-specific DCF action is further supported by comparing mitochondrial parameters in DCF-treated cells to the same parameters in cells treated with selective respiratory inhibitors: no similarities were found between the experimental variants. Conclusions: The results obtained in this work suggest that DCF strongly affects cells that experience mild metabolic or developmental disorders, not revealed under control conditions, while more vital cells are affected only slightly, as it was already indicated in literature. In the cells suffering from DCF treatment, the drug influence on mitochondria functioning in a non-specific way, destroying the structure of mitochondrial membranes. This primary effect probably led to the mitochondrial inner membrane permeability transition and the uncoupling of oxidative phosphorylation. It can be assumed that mitochondrial dysfunction is an important factor in DCF phytotoxicity. Because studies of the effects of NSAIDs on the functioning of plant mitochondria are relatively scarce, the present work is an important contribution to the elucidation of the mechanism of NSAID toxicity toward non-target plant organisms.

Role of Antioxidant Enzymes in Pathogenesis of Oral Squamous Cell Carcinoma: a Systematic Review and Meta-analysis.

OBJECTIVE: To investigate the antioxidant enzyme status in biological samples of patients with oral squamous cell carcinoma (OSCC) and compare them with biological samples of healthy people through a systematic review and meta-analysis. METHODS: Antioxidant enzymes of catalase (CAT), sodium dismutase (SOD) and glutathione peroxide (GPx) were included in the analysis. A literature search was conducted of the PubMed, Science Direct, Scopus, Web of Science and Wiley Online Library databases for studies published between January 1999 and December 2022. A total of 831 articles were selected, of which 131 were found to be relevant. Finally, the full texts of 12 studies were screened and included. Studies that evaluated other antioxidant enzymes were excluded. Standardised mean difference (SMD) was derived to conduct a meta-analysis using comprehensive meta-analysis v3 (Biostat, Englewood, NJ, USA). A random effects model with 95% confidence interval (CI) was used to estimate the effect size. P < 0.05 was considered significant. RESULTS: CAT levels were measured in eight studies (n = 567) and the mean values for the OSCC and control groups were 4.81 ± 2.57 and 10.02 ± 1.81, respectively (SMD 3.18, 95% CI 1.01 to 1.42; P = 0.001). SOD level was evaluated in 11 studies (n = 762) and the values for the OSCC and control groups were 3.78 ± 1.45 and 7.34 ± 1.79, respectively (SMD 3.66, 95% CI 1.51 to 1.94; P = 0.001). GPx level was evaluated in 10 studies (n = 697) and the values for the OSCC and control groups were 13.33 ± 1.42 and 16.54 ± 2.9, respectively (SMD 1.91, 95% CI 1.34 to 1.77; P = 0.001). The heterogeneity between the studies was severe (I2 ≥ 90%). The risk of bias between studies was low to moderate. CONCLUSION: Analysis revealed that the levels of antioxidant enzymes decreased in biological samples of patients with OSSC as compared to healthy controls. Understanding the pathological progress of OSCC by analysing the level of antioxidant enzymes is beneficial in formulating a personalised, targeted pro-oxidant therapy for cancer treatment.

Metabolic engineering of Escherichia coli for high-level production of benzyl acetate from glucose.

BACKGROUND: Benzyl acetate is an aromatic ester with a jasmine scent. It was discovered in plants and has broad applications in food, cosmetic, and pharmaceutical industries. Its current production predominantly relies on chemical synthesis. In this study, Escherichia coli was engineered to produce benzyl acetate. RESULTS: Two biosynthetic routes based on the CoA-dependent ß-oxidation pathway were constructed in E. coli for benzyl acetate production. In route I, benzoic acid pathway was extended to produce benzyl alcohol by combining carboxylic acid reductase and endogenous dehydrogenases and/or aldo-keto reductases in E. coli. Benzyl alcohol was then condensed with acetyl-CoA by the alcohol acetyltransferase ATF1 from yeast to form benzyl acetate. In route II, a plant CoA-dependent ß-oxidation pathway via benzoyl-CoA was assessed for benzyl alcohol and benzyl acetate production in E. coli. The overexpression of the phosphotransacetylase from Clostridium kluyveri (CkPta) further improved benzyl acetate production in E. coli. Two-phase extractive fermentation in situ was adopted and optimized for benzyl acetate production in a shake flask. The most optimal strain produced 3.0 ± 0.2 g/L benzyl acetate in 48 h by shake-flask fermentation. CONCLUSIONS: We were able to establish the whole pathway for benzyl acetate based on the CoA-dependent ß-oxidation in single strain for the first time. The highest titer for benzyl acetate produced from glucose by E. coli is reported. Moreover, cinnamyl acetate production as an unwanted by-product was very low. Results provided novel information regarding the engineering benzyl acetate production in microorganisms.

Ping, pong, and freeze: Structural insights into the inhibition of ceramide synthase by Fumonisin B1.

Fumonisin B1 (FB1) targets sphingolipid biosynthesis, inhibiting ceramide synthases. In this issue of Structure, Zhang et al.1 determined the cryoelectron microscopic structures of yeast ceramide synthase in complex with FB1 and its acylated derivative, acyl-FB1, revealing a two-step "ping-pong" mechanism for the N-acylation of FB1 and how it inhibits ceramide synthase.

The Mycobacterium tuberculosis Cell Wall: An Alluring Drug Target for Developing Newer Anti-TB Drugs-A Perspective.

The Mycobacterium cell wall is a capsule-like structure comprising of various layers of biomolecules such as mycolic acid, peptidoglycans, and arabinogalactans, which provide the Mycobacteria a sort of cellular shield. Drugs like isoniazid, ethambutol, cycloserine, delamanid, and pretomanid inhibit cell wall synthesis by inhibiting one or the other enzymes involved in cell wall synthesis. Many enzymes present across these layers serve as potential targets for the design and development of newer anti-TB drugs. Some of these targets are currently being exploited as the most druggable targets like DprE1, InhA, and MmpL3. Many of the anti-TB agents present in clinical trials inhibit cell wall synthesis. The present article covers a systematic perspective of developing cell wall inhibitors targeting various enzymes involved in cell wall biosynthesis as potential drug candidates for treating Mtb infection.

1-Deoxy-d-xylulose 5-phosphate reductoisomerase as target for anti Toxoplasma gondii agents: crystal structure, biochemical characterization and biological evaluation of inhibitors.

Toxoplasma gondii is a widely distributed apicomplexan parasite causing toxoplasmosis, a critical health issue for immunocompromised individuals and for congenitally infected foetuses. Current treatment options are limited in number and associated with severe side effects. Thus, novel anti-toxoplasma agents need to be identified and developed. 1-Deoxy-d-xylulose 5-phosphate reductoisomerase (DXR) is considered the rate-limiting enzyme in the non-mevalonate pathway for the biosynthesis of the isoprenoid precursors isopentenyl pyrophosphate and dimethylallyl pyrophosphate in the parasite, and has been previously investigated for its key role as a novel drug target in some species, encompassing Plasmodia, Mycobacteria and Escherichia coli. In this study, we present the first crystal structure of T. gondii DXR (TgDXR) in a tertiary complex with the inhibitor fosmidomycin and the cofactor NADPH in dimeric conformation at 2.5 Šresolution revealing the inhibitor binding mode. In addition, we biologically characterize reverse α-phenyl-ß-thia and ß-oxa fosmidomycin analogues and show that some derivatives are strong inhibitors of TgDXR which also, in contrast with fosmidomycin, inhibit the growth of T. gondii in vitro. Here, ((3,4-dichlorophenyl)((2-(hydroxy(methyl)amino)-2-oxoethyl)thio)methyl)phosphonic acid was identified as the most potent anti T. gondii compound. These findings will enable the future design and development of more potent anti-toxoplasma DXR inhibitors.

Discovery of Novel (5-Mercapto-4-phenyl-4H-1,2,4-triazol-3-yl)methyl Phenyl Carbamate as a Potent Phytoene Desaturase Inhibitor through Scaffold Hopping and Linker Modification.

Phytoene desaturase (PDS) is a key rate-limiting enzyme in the carotenoid biosynthesis pathway. Although commercial PDS inhibitors have been developed for decades, it remains necessary to develop novel PDS inhibitors with higher bioactivity. In this work, we used the scaffold hopping and linker modification approaches to design and synthesize a series of compounds (7a-7o, 8a-8l, and 14a-14d). The postemergence application assay demonstrated that 8e and 7e separately showed the best herbicidal activity at 750 g a.i./ha and lower doses (187.5 g, 375g a.i./ha) without no significant toxicity to maize and wheat. The surface plasmon resonance revealed strong binding affinity between 7e and Synechococcus PDS (SynPDS). The HPLC analysis confirmed that 8e at 750 g a.i./ha caused significant phytoene accumulation in Arabidopsis seedlings. This work demonstrates the efficacy of structure-guided optimization through scaffold hopping and linker modification to design potent PDS inhibitors with enhanced bioactivity and crop safety.

Programming of a Portable Digital Monitoring System-Integrated DNA Aptamer Reversely Regulated Oxidase-Like Nanozyme for Real-Time Dynamic Analysis of Atmospheric Perfluorooctanoic Acid.

Timely and efficient analysis of the fluorinated per- and polyfluoroalkyl substances (PFAS) in an atmospheric environment is critical to environmental pollution traceability, early warnings, and governance. Here, a portable, reliable, and intelligent digital monitoring device for onsite real-time dynamic analysis of atmospheric perfluorooctanoic acid (PFOA) is proposed. The sensing mechanism is attributed to the oxidase-like activity of PtCoNPs@g-C3N4 that is reversely regulated by the surface modification of a PFOA-recognizable DNA aptamer, engineering a PFOA-activated oxidase-like activity of nanozyme (Apt-PtCoNPs@g-C3N4) to combine the nonfluorescence o-phenylenediamine (OPD) as the dual-modality response system. The present PFOA interacts with its DNA aptamer and dissociates from the surface of Apt-PtCoNPs@g-C3N4, restoring the oxidase-like activity of PtCoNPs@g-C3N4 to oxidize OPD into yellow fluorescence 2,3-diphenylaniline (DAP), thereby observing a PFOA-triggered colorimetric as well as fluorescence dual-modality change. Then, a hydrogel kit-programmed Apt-PtCoNPs@g-C3N4 + OPD system is used as the sensitive element to incorporate into this homemade portable device, automatically gathering and processing the PFOA-triggered hydrogel colorimetric and fluorescence image gray values by our self-weaving software, ultimately realizing the onsite real-time dynamic analysis of atmospheric PFOA surrounding a fluorochemical production plant. This work provides a direction and theoretical foundation for designing portable onsite screening devices that cater to other atmospheric contaminants detection requirements.

Cytochrome c Oxidase Influences Pyraclostrobin Sensitivity in Fusarium graminearum by Regulating FgAox Through Transcription Factors FgAod2 and FgAod5.

Cytochrome c oxidase (Cox) is a crucial terminal oxidase in the electron transport chain. In this study, we generated 14 Cox gene deletion or overexpression mutants in Fusarium graminearum. Fungicide sensitivity tests revealed that 11 Cox gene deletion mutants displayed resistance to pyraclostrobin, while 10 overexpression mutants showed hypersensitivity. RNA-Seq and RT-qPCR analyses demonstrated the upregulation of FgAox (alternative oxidase in F. graminearum), FgAod2, and FgAod5 (alternative oxidase deficiency in F. graminearum) in ΔFgCox4-2 and ΔFgCox17-75 mutants. In 11 Cox gene deletion mutants, FgAox expression was significantly upregulated, whereas in 10 Cox gene overexpression mutants, it was significantly downregulated. FgAox overexpression mutants exhibit resistance to pyraclostrobin, while FgAox deletion mutants show hypersensitivity to pyraclostrobin. FgAod2 and FgAod5 were identified as transcription factors for FgAox. Our findings reveal that FgCox influences pyraclostrobin sensitivity by regulating FgAox through FgAod2 and FgAod5. Understanding pyraclostrobin resistance mechanisms in F. graminearum could help develop better fungicide rotation and application strategies to manage resistance and guide the creation of new fungicides targeting different pathways.