Ag-Catalyzed Selective C-C Bond Activation of Cyclopropenones to Access α-Alkylidene Lactones.

A novel Ag-catalyzed ring opening of unsymmetric cyclopropenones for the stereoselective synthesis of a diverse range of α-alkylidene lactones has been developed. In this protocol, two different C-C(O) bonds were distinguished, demonstrating selective C-C bond activation. This reaction features a wide substrate scope, good functional group compatibility, and high atom economy, providing a versatile and general approach to the construction of α-alkylidene lactones.

More Than One Enzyme: Exploring Alternative FMN-Dependent L-Lactate Oxidases for Biosensor Development.

The α-hydroxy acid oxidoreductase (HAOx) family contains a diverse group of enzymes that can be applied in biosensors for L-lactate detection, most prominently lactate oxidase (LOx). The limited availability and a lack of diversity of L-lactate-oxidizing enzymes have currently hindered advancements in L-lactate biosensor development. Until now, the field has mostly relied on a single, commercially available enzyme, namely Aerococcus viridans L-lactate oxidase (AvLOx). In this study, we present newly discovered alternative L-lactate oxidases that exhibit a narrow substrate specificity and varied kinetic efficiencies toward L-lactate, making them suitable for integration into existing biosensor configurations. Some of these FMN-dependent L-lactate oxidases could be obtained in substantial amounts from routine E. coli expression, potentially facilitating commercial production. Using electrochemical characterization with a mediated biosensor setup, we present 7 enzymes that perform comparable or even better than commercial AvLOx. Finally, we show that their electrochemical performance is not directly correlating with their biochemical performance, making predictions of the suitability of enzymes for biosensor applications extremely difficult. Our research emphasizes the significance of expanding the enzyme toolbox of L-lactate oxidases for the development of improved L-lactate biosensors.

Interfamily Grafted Hybrids Vitis vinifera/Schisandra chinensis Resulted in Transcriptomic, Phenotypic, and Metabolic Changes.

Long-distance transfer of genetic material and metabolites between rootstock and scions is well documented in homo-grafted hybrids but has rarely been reported in genetically-distant grafts where the rootstock and scion belong to different families. In this study, we grafted Vitis vinifera scions onto Schisandra chinensis stocks and obtained 20 vegetative hybrids, Vitis vinifera/Schisandra chinensis (Vs). After 25 years of growth, we found that the phenotypes of the leaves, internodes, and fruits of the Vs hybrids above the graft union resembled an intermediate phenotype between V. vinifera and S. chinensis, and the new traits were stable when propagated vegetatively. We further analyzed genetic differences between Vv plants and Vs hybrids using high-throughput sequencing, while metabolomes were analyzed by liquid chromatography-mass spectrometry (LC-MS). We found a total of 2113 differentially expressed genes (DEGs). GO annotation and KEGG pathway enrichment analysis showed that these DEGs enriched mainly in oxidation-reduction and metabolic processes. Seventy-nine differentially expressed miRNAs (DEMs) containing 27 known miRNAs and 52 novel miRNAs were identified. A degradation analysis detected 840 target genes corresponding to 252 miRNAs, of which 12 DEMs and their corresponding target gene expression levels were mostly negatively correlated. Furthermore, 1188 differential metabolic compounds were identified. In particular, in Vs hybrids, the abundance of the metabolites schizandrin and gomisin as the main medicinal ingredients in S. chinensis were down-regulated and up-regulated, respectively. Our data demonstrated the effects of interfamily grafts on the phenotype, transcript profile and metabolites of the scion, and also provided new insight into the genetic, phenotypic, and metabolic plasticity associated with genetically distant grafted hybrids.

Accurate diagnosis of severe coronary stenosis based on resting magnetocardiography: a prospective, single-center, cross-sectional analysis.

OBJECTIVE: To evaluate the role of resting magnetocardiography in identifying severe coronary artery stenosis in patients with suspected coronary artery disease. METHODS: A total of 513 patients with angina symptoms were included and divided into two groups based on the extent of coronary artery disease determined by angiography: the non-severe coronary stenosis group (< 70% stenosis) and the severe coronary stenosis group (≥ 70% stenosis). The diagnostic model was constructed using magnetic field map (MFM) parameters, either individually or in combination with clinical indicators. The performance of the models was evaluated using receiver operating characteristic curves, accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Calibration plots and decision curve analysis were performed to investigate the clinical utility and performance of the models, respectively. RESULTS: In the severe coronary stenosis group, QR_MCTDd, S_MDp, and TT_MAC50 were significantly higher than those in the non-severe coronary stenosis group (10.46 ± 10.66 vs. 5.11 ± 6.07, P < 0.001; 7.2 ± 8.64 vs. 4.68 ± 6.95, P = 0.003; 0.32 ± 57.29 vs. 0.26 ± 57.29, P < 0.001). While, QR_MVamp, R_MA, and T_MA in the severe coronary stenosis group were lower (0.23 ± 0.16 vs. 0.28 ± 0.16, P < 0.001; 55.06 ± 48.68 vs. 59.24 ± 53.01, P < 0.001; 51.67 ± 39.32 vs. 60.45 ± 51.33, P < 0.001). Seven MFM parameters were integrated into the model, resulting in an area under the curve of 0.810 (95% CI: 0.765-0.855). The sensitivity, specificity, PPV, NPV, and accuracy were 71.7%, 80.4%, 93.3%, 42.8%, and 73.5%; respectively. The combined model exhibited an area under the curve of 0.845 (95% CI: 0.798-0.892). The sensitivity, specificity, PPV, NPV, and accuracy were 84.3%, 73.8%, 92.6%, 54.6%, and 82.1%; respectively. Calibration curves demonstrated excellent agreement between the nomogram prediction and actual observation. The decision curve analysis showed that the combined model provided greater net benefit compared to the magnetocardiography model. CONCLUSIONS: The novel quantitative MFM parameters, whether used individually or in combination with clinical indicators, have been shown to effectively predict the risk of severe coronary stenosis in patients presenting with angina-like symptoms. Magnetocardiography, an emerging non-invasive diagnostic tool, warrants further exploration for its potential in diagnosing coronary heart disease.

Pd-Catalyzed Three-Component Coupling of Cyclopropenones via Sequential C-C Bond Activation and Allylation.

A novel Pd-catalyzed three-component domino reaction for the stereoselective synthesis of highly functionalized allyl cinnamates has been developed. In this protocol, a sequential process of C-C bond activation and intermolecular allylic substitution was well-organized. The key for this transformation is the in situ generated hydrolysis product of cyclopropenone, which triggered a new reaction with vinylethylene carbonates. The reaction mechanism was investigated, demonstrating the high stereoselectivity and excellent atomic economy in this process.

Integrated single-cell transcriptome and T cell receptor profiling reveals defects of T cell exhaustion in pulmonary tuberculosis.

Tuberculosis-affected lungs with chronic inflammation harbor abundant immunosuppressive immune cells but the nature of such inflammation is unclear. Dysfunction in T cell exhaustion, while implicated in chronic inflammatory diseases, remains unexplored in tuberculosis. Given that immunotherapy targeting exhaustion checkpoints exacerbates tuberculosis, we speculate that T cell exhaustion is dysfunctional in tuberculosis. Using integrated single-cell RNA sequencing and T cell receptor profiling we reported defects in exhaustion responses within inflamed tuberculosis-affected lungs. Tuberculosis lungs demonstrated significantly reduced levels of exhausted CD8+ T cells and exhibited diminished expression of exhaustion-related transcripts among clonally expanded CD4+ and CD8+ T cells. Additionally, clonal expansion of CD4+ and CD8+ T cells bearing T cell receptors specific for CMV was observed. Expanded CD8+ T cells expressed the cytolytic marker GZMK. Hence, inflamed tuberculosis-affected lungs displayed dysfunction in T cell exhaustion. Our findings likely hold implications for understanding the reactivation of tuberculosis observed in patients undergoing immunotherapy targeting the exhaustion checkpoint.

A patient-specific lung cancer assembloid model with heterogeneous tumor microenvironments.

Cancer models play critical roles in basic cancer research and precision medicine. However, current in vitro cancer models are limited by their inability to mimic the three-dimensional architecture and heterogeneous tumor microenvironments (TME) of in vivo tumors. Here, we develop an innovative patient-specific lung cancer assembloid (LCA) model by using droplet microfluidic technology based on a microinjection strategy. This method enables precise manipulation of clinical microsamples and rapid generation of LCAs with good intra-batch consistency in size and cell composition by evenly encapsulating patient tumor-derived TME cells and lung cancer organoids inside microgels. LCAs recapitulate the inter- and intratumoral heterogeneity, TME cellular diversity, and genomic and transcriptomic landscape of their parental tumors. LCA model could reconstruct the functional heterogeneity of cancer-associated fibroblasts and reflect the influence of TME on drug responses compared to cancer organoids. Notably, LCAs accurately replicate the clinical outcomes of patients, suggesting the potential of the LCA model to predict personalized treatments. Collectively, our studies provide a valuable method for precisely fabricating cancer assembloids and a promising LCA model for cancer research and personalized medicine.

Progress in polystyrene biodegradation by insect gut microbiota.

Polystyrene (PS) is frequently used in the plastics industry. However, its structural stability and difficulty to break down lead to an abundance of plastic waste in the environment, resulting in micro-nano plastics (MNPs). As MNPs are severe hazards to both human and environmental health, it is crucial to develop innovative treatment technologies to degrade plastic waste. The biodegradation of plastics by insect gut microorganisms has gained attention as it is environmentally friendly, efficient, and safe. However, our knowledge of the biodegradation of PS is still limited. This review summarizes recent research advances on PS biodegradation by gut microorganisms/enzymes from insect larvae of different species, and schematic pathways of the degradation process are discussed in depth. Additionally, the prospect of using modern biotechnology, such as genetic engineering and systems biology, to identify novel PS-degrading microbes/functional genes/enzymes and to realize new strategies for PS biodegradation is highlighted. Challenges and limitations faced by the application of genetically engineered microorganisms (GEMs) and multiomics technologies in the field of plastic pollution bioremediation are also discussed. This review encourages the further exploration of the biodegradation of PS by insect gut microbes/enzymes, offering a cutting-edge perspective to identify PS biodegradation pathways and create effective biodegradation strategies.

Feasibility and Clinical Utility of Reporting Hereditary Cancer Predisposition Pathogenic Variants Identified in Research Germline Sequencing: A Prospective Interventional Study.

PURPOSE: Patients with cancer frequently undergo research-grade germline sequencing but clinically actionable results are not routinely disclosed. The objective of this study is to evaluate the feasibility of reporting clinically relevant secondary findings (SF) identified in germline research sequencing using the institutional molecular tumor board (MTB) and the treating oncology physician. METHODS: This prospective, interventional cohort study enrolled Total Cancer Care participants with any cancer diagnosis at a single institution. Patients underwent research-grade germline whole-exome sequencing, with bioinformatic analysis in a Clinical Laboratory Improvement Amendments-certified laboratory to verify pathogenic/likely pathogenic germline variants (PGVs) in any American College of Medical Genomics and Genetics SF v2.0 genes. After a protocol modification in consenting patients, the MTB reported PGVs to treating oncology physicians with recommendations for referral to a licensed genetic counselor and clinical confirmatory testing. RESULTS: Of the 781 enrolled participants, 32 (4.1%) harbored cancer predisposition PGVs, 24 (3.1%) were heterozygous carriers of an autosomal recessive cancer predisposition syndrome, and 14 (1.8%) had other hereditary disease PGVs. Guideline-directed testing would have missed 37.5% (12/32) of the inherited cancer predisposition PGVs, which included BRCA1, BRCA2, MSH6, SDHAF2, SDHB, and TP53 variants. Three hundred fifteen participants consented to reporting results; results for all living patients were reported to the clinical team with half referred to a licensed genetic counselor. There was concordance between all research variants identified in patients (n = 9) who underwent clinical confirmatory sequencing. CONCLUSION: MTB reporting of research-grade germline sequencing to the clinical oncology team is feasible. Over a third of PGVs identified using a universal testing strategy would have been missed by guideline-based approach, suggesting a role for expanding germline testing.

Revealing the degrading-possibility of methyl red by two azoreductases of Anoxybacillus sp. PDR2 based on molecular docking.

Azo dyes, as the most widely used synthetic dyes, are considered to be one of the culprits of water resources and environmental pollution. Anoxybacillus sp. PDR2 is a thermophilic bacterium with the ability to degrade azo dyes, whose genome contains two genes encoding azoreductases (named AzoPDR2-1 and AzoPDR2-2). In this study, through response surface methodology (RSM), when the initial pH, inoculation volume and Mg2+ addition amount were 7.18, 10.72% and 0.1 g/L respectively, the decolorization rate of methyl red (MR) (200 mg/L) could reach its maximum (98.8%). The metabolites after biodegradation were detected by UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), and liquid chromatography mass spectrometry (LC-MS/MS), indicating that MR was successfully decomposed into 4-aminobenzoic acid and other small substrates. In homologous modeling, it was found that both azoreductases were flavin-dependent azoreductases, and belonged to the α/ß structure, using the Rossmann fold. In their docking results with the cofactor flavin mononucleotide (FMN), FMN bound to the surface of the protein dimer. Nicotinamide adenine dinucleotide (NADH) was superimposed on the plane of the pyrazine ring between FMN and the activity pocket of protein. Besides, both azoreductase complexes (azoreductase-FMN-NADH) exhibited a substrate preference for MR. Asn104 and Tyr74 played an important role in the combination of the azoreductase AzoPDR2-1 complex and the azoreductase AzoPDR2-2 complex with MR, respectively. This provided assistance for studying the mechanism of azoreductase biodegradation of azo dyes in thermophilic bacteria.

New insights into the typical nitrogen-containing heterocyclic compound-quinoline degradation and detoxification by microbial consortium: Integrated pathways, meta-transcriptomic analysis and toxicological evaluation.

As the primary source of COD in industrial wastewater, quinoline has aroused increasing attention because of its potential teratogenic, carcinogenic, and mutagenic effects in the environment. The activated sludge isolate quinoline-degrading microbial consortium (QDMC) efficiently metabolizes quinoline. However, the molecular underpinnings of the degradation mechanism of quinoline by QDMC have not been elucidated. High-throughput sequencing revealed that the dominant genera included Diaphorobacter, Bacteroidia, Moheibacter and Comamonas. Furthermore, a positive strong correlation was observed between the key bacterial communities (Diaphorobact and Bacteroidia) and quinoline degradation. According to metatranscriptomics, genes associated with quorum sensing, ABC transporters, component systems, carbohydrate, aromatic compound degradation, energy metabolism and amino metabolism showed high expression, thus improving adaptability of microbial community to quinoline stress. In addition, the mechanism of QDMC in adapting and resisting to extreme environmental conditions in line with the corresponding internal functional properties and promoting biogegradation efficiency was illustrated. Based on the identified products, QDMC effectively mineralized quinoline into low-toxicity metabolites through three major metabolic pathways, including hydroxyquinoline, 1,2,3,4-H-quinoline, 5,6,7,8-tetrahydroquinoline and 1-oxoquinoline pathways. Finally, toxicological, genotoxicity and phytotoxicity studies supported the detoxification of quinoline by the QDMC. This study provided a promising approach for the stable, environmental-friendly and efficient bioremediation applications for quinoline-containing wastewater.

Phenotype versus genotype discordant rifampicin susceptibility testing in tuberculosis: implications for a diagnostic accuracy.

IMPORTANCE: An accurate diagnosis of drug resistance in clinical isolates is an important step for better treatment outcomes. The current study observed a higher discordance rate of rifampicin resistance on Mycobacteria Growth Indicator Tube (MGIT) drug susceptibility testing (DST) than Lowenstein-Jenson (LJ) DST when compared with the rpoB sequencing. We detected a few novel mutations and their combination in rifampicin resistance isolates that were missed by MGIT DST and may be useful for the better management of tuberculosis (TB) treatment outcomes. Few novel deletions in clinical isolates necessitate the importance of rpoB sequencing in large data sets in geographic-specific locations, especially high-burden countries. We explored the discordance rate on MGIT and LJ, which is important for the clinical management of rifampicin resistance to avoid the mistreatment of drug-resistant TB. Furthermore, MGIT-sensitive isolates may be subjected to molecular methods of diagnosis for further confirmation and treatment options.

Doxercalciferol alleviates UVB-induced HaCaT cell senescence and skin photoaging.

Prolonged or excessive ultraviolet (UV) exposure can lead to premature skin aging. Doxercalciferol (Dox), an analog of vitamin D2, is chiefly used to treat endocrine diseases, cardiovascular diseases, kidney diseases, etc. To date, research on Dox in alleviating photoaging and UV-induced inflammation is scarce. In this research, we evaluated the function of Dox in ultraviolet radiation B (UVB)-induced photoaging and explored the potential mechanism in human keratinocytes (Hacat) and BALB/c mice. First, we established a stable UVB-induced photoaging cell model. Then, we found that the senescence ß-galactosidase (SA-ß-Gal) positive rate, senescence-related protein (p16), aging-related genes (p21 and p53), senescence-associated secretory phenotype (SASP), inflammatory driving factors (IL-1ß and IL-6) and matrix metalloproteinases (MMPs) (MMP1 and MMP9) were upregulated in HaCaT cells after UVB irradiation. At the same time, the effect of UVB on the back skin of BALB/c mice showed a consistent trend. Dox effectively alleviated the aforementioned changes caused by UVB radiation. Mechanistically, we found that UVB activated mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) signaling pathways, and Dox inhibited UVB-activated NF-κB and MAPK. Furthermore, Dox inhibited UVB-induced skin photoaging and damage in mice. In summary, Dox has been improved to inhibit photoaging, which may help to develop therapies to delay skin photoaging.

Microfluidic magnetic detection system combined with a DNA framework-mediated immune-sandwich assay for rapid and sensitive detection of tumor-derived exosomes.

Tumor-derived circulating exosomes (TDEs) are being pursued as informative and noninvasive biomarkers. However, quantitatively detecting TDEs is still challenging. Herein, we constructed a DNA tetrahedral-structured probe (TSP)-mediated microfluidic magnetic detection system (µFMS) to provide a rapid and sensitive platform for analyzing TDEs. CD63 aptamer-modified Fe3O4 magnetic nanoparticles (MNPs) were constructed to form magnetic nano-report probes (MNRs). The microfluidic chips were fabricated from glass functionalized with DNA TSP-modified aldehyde groups and a PDMS layer designed with serpentine microchannels. An induction coil-based magnetic detector was used to measure the magnetic signal. The linear dynamic range of the µFMS system for TDE assays was 1.98 × 103-1.98 × 107 particles/mL with a limit of detection of 1.98 × 103 particles/mL in PBS. There was no significant difference in TDE detection between the simulated serum and PBS, which indicated the feasibility of the constructed µFMS system for TDE analysis in complex biological systems. In terms of cost, reaction time and operation procedure, this µFMS has the potential to be developed as a clinical point-of-care testing tool for cancer diagnosis and therapeutics.

A derived weedy rice × ancestral cultivar cross identifies evolutionarily relevant weediness QTLs.

Weedy rice (Oryza spp.) is a weedy relative of the cultivated rice that competes with the crop and causes significant production loss. The BHA (blackhull awned) US weedy rice group has evolved from aus cultivated rice and differs from its ancestors in several important weediness traits, including flowering time, plant height and seed shattering. Prior attempts to determine the genetic basis of weediness traits in plants using linkage mapping approaches have not often considered weed origins. However, the timing of divergence between crossed parents can affect the detection of quantitative trait loci (QTL) relevant to the evolution of weediness. Here, we used a QTL-seq approach that combines bulked segregant analysis and high-throughput whole genome resequencing to map the three important weediness traits in an F2 population derived from a cross between BHA weedy rice with an ancestral aus cultivar. We compared these QTLs with those previously detected in a cross of BHA with a more distantly related crop, indica. We identified multiple QTLs that overlapped with regions under selection during the evolution of weedy BHA rice and some candidate genes possibly underlying the evolution weediness traits in BHA. We showed that QTLs detected with ancestor-descendant crosses are more likely to be involved in the evolution of weediness traits than those detected from crosses of more diverged taxa.

Effects of microcystin on protein profile in hepatopancreas of Litopenaeus vannamei.

For intensive aquaculture in freshwater ponds, microcystin (MC-LR) generated from cyanobacterial blooms is one of the bottlenecks for the healthy and sustainable development of shrimp aquaculture industry. In this study, we measured the MC-LR content in the hepatopancreas and muscles of Litopenaeus vannamei stressed by MC-LR, and analyzed protein expression in the hepatopancreas using DIA high-throughput proteomics technology. The results showed that MC-LR content in the hepatopancreas and muscles reached the highest at 1 h after MC-LR injection, which was (6.12±0.45) µg·kg-1 and (5.00±0.19) µg·kg-1, respectively. Then, it decreased gra-dually, with that in the hepatopancreas being significantly higher than in muscles. We identified 820 differential expressed proteins, including 586 up-regulated and 234 down-regulated ones. Results of bioinformatics analysis showed that MC-LR stress significantly affected immune-related pathways such as lysosome, RIG-Ⅰ receptor signals and interleukin-2. It also altered energy metabolisms including citrate cycle, metabolism of starch and sucrose, and interconversion of pentose and glucoronate, which in turn led to the disorder of carbohydrate metabolism. In addition, MC-LR significantly upregulated 19 cytoskeleton-related blood shadow proteins and damaged the hepatopancreas cytoskeleton. It was concluded that MC-LR mainly affected the physiological processes associated with immunity, energy metabolism, and cytoskeleton in the hepatopancreas of L. vannamei.

Single-cell RNA-sequencing reveals heterogeneity and intercellular crosstalk in human tuberculosis lung.

Lung inflammation indicated by 18F-labeled fluorodeoxyglucose (FDG) in patients with tuberculosis is associated with disease severity and relapse risk upon treatment completion. We revealed the heterogeneity and intercellular crosstalk in lung tissues with 18F-FDG avidity and adjacent uninvolved tissues from 6 tuberculosis patients by single-cell RNA-sequencing. Tuberculous lungs had an influx of regulatory T cells (Treg), exhausted CD8 T cells, immunosuppressive myeloid cells, conventional DC, plasmacytoid DC, and neutrophils. Immune cells in inflamed lungs showed general up-regulation of ATP synthesis and interferon-mediated signaling. Immunosuppressive myeloid and Treg cells strongly displayed transcriptions of genes related to tuberculosis disease progression. Intensive crosstalk between IL4I1-expressing myeloid cells and Treg cells involving chemokines, costimulatory molecules, and immune checkpoints, some of which are specific in 18F-FDG-avid lungs, were found. Our analysis provides insights into the transcriptomic heterogeneity and cellular crosstalk in pulmonary tuberculosis and guides unveiling cellular and molecular targets for tuberculosis therapy.

Serum protein profile analysis via label-free quantitation proteomics in patients with early-onset preeclampsia.

BACKGROUND: Preeclampsia (PE) is a serious pregnancy complication, resulting in potentially life-threatening conditions for both mother and foetus. It is worth noting that early-onset PE has become a great challenge for clinicians due to its complex manifestation, rapid progression and serious complications. This study aims to investigate differential serum proteome profiles in patients with early-onset PE. METHODS: Each serum sample was separated using a nanoliter flow rate Easy-nLC chromatography system. Then the samples were analysed by mass spectrometry. Bioinformatics analyses were conducted to analyse the functional categories or signal transduction pathways for differentially abundant proteins. Key proteins identified by mass spectrometry were verified by ELISA. RESULTS: We found 30 and 34 proteins were upregulated and downregulated in early-onset PE patients (n = 3) vs controls (n = 3), respectively. Functional enrichment analysis revealed differentially expressed proteins related to the immune response and regulation of peptidase activity. ELISA confirmed that there were lower CSH1 levels and higher LPA concentrations in the serum samples of early-onset PE patients (n = 22) than in healthy controls (n = 19) (p < 0.05 for CSH1 and p < 0.001 for LPA). CONCLUSIONS: This study revealed the critical features of serum proteins in early-onset PE patients. LPA and CSH1 may serve as biomarkers for early-onset PE diagnosis and therapy.

Early-onset preeclampsia (PE) is still lacking definitive diagnostic or therapeutic strategies. Thus, we tried to identify effective and specific biomarkers for early-onset PE. In this study, we explored the serum protein profiles through the approach of label-free quantitation proteomics between early-onset PE patients and healthy controls. We identified 64 differentially expressed proteins in early-onset PE patients' serum samples. These differentially expressed proteins are associated with the immune response and regulation of peptidase activity. In addition, our findings suggest that LPA and CSH1 may serve as candidate biomarkers for early-onset PE diagnosis and therapy. These results may help physicians to diagnose early-onset PE clinically. What's more, our findings provide new insights into the onset and progression of early-onset PE disease.

Genome-wide association study of maize resistance to Pythium aristosporum stalk rot.

Stalk rot, a severe and widespread soil-borne disease in maize, globally reduces yield and quality. Recent documentation reveals that Pythium aristosporum has emerged as one of the dominant causal agents of maize stalk rot. However, a previous study of maize stalk rot disease resistance mechanisms and breeding had mainly focused on other pathogens, neglecting P. aristosporum. To mitigate crop loss, resistance breeding is the most economical and effective strategy against this disease. This study involved characterizing resistance in 295 inbred lines using the drilling inoculation method and genotyping them via sequencing. By combining with population structure, disease resistance phenotype, and genome-wide association study (GWAS), we identified 39 significant single-nucleotide polymorphisms (SNPs) associated with P. aristosporum stalk rot resistance by utilizing six statistical methods. Bioinformatics analysis of these SNPs revealed 69 potential resistance genes, among which Zm00001d051313 was finally evaluated for its roles in host defense response to P. aristosporum infection. Through virus-induced gene silencing (VIGS) verification and physiological index determination, we found that transient silencing of Zm00001d051313 promoted P. aristosporum infection, indicating a positive regulatory role of this gene in maize's antifungal defense mechanism. Therefore, these findings will help advance our current understanding of the underlying mechanisms of maize defense to Pythium stalk rot.