Flavonols have been implicated in male sterility and pollen tube growth for over three decades; however, the molecular mechanisms mediating their accumulation in pollen grains remain poorly understood. In this study, a multidrug and toxic compound extrusion (MATE) transporter, OsMATE7, was identified as a key regulator of flavonol accumulation in mature pollen grains, thereby promoting pollen tube growth in rice (Oryza sativa). Mutation of OsMATE7 resulted in a significant reduction in seed setting rates. Reciprocal crosses between OsMATE7 knockout (KO) and wild-type plants, along with both in vivo and in vitro germination assays, demonstrated that the mutant exhibited male sterility due to defective pollen tube growth. OsMATE7 was found to be specifically expressed in pollen and localized to the endoplasmic reticulum (ER). Diphenylboric acid 2-aminoethylester (DPBA) staining assay revealed a significant reduction in flavonol accumulation in mature pollen grains of OsMATE7. Functional analysis of flavonol transport and flavonoid content confirmed that OsMATE7 serves as a potential flavonol transporter, facilitating the accumulation of flavonols in mature pollen grains. Further investigation revealed that flavonol deficiency in mutant pollen grains inhibited α-amylase activity and blocked starch hydrolysis, ultimately impairing pollen tube growth. These findings elucidate a novel mechanism by which OsMATE7 regulates flavonol distribution to control pollen tube growth, providing new insights into the role of MATE proteins in seed setting and crop breeding.

The radiotoxicity and chemical toxicity of UO22+ pose a long-term threat to ecosystems and human health through bioaccumulation and biomagnification. Therefore, there is an urgent need to develop highly sensitive and selective detection methods for UO22+. Here, we developed a near-infrared (NIR) fluorescent probe RU, built on a xanthene core structure. Upon binding with UO22+, RU undergoes ring-opening, triggering fluorescence turn on. RU exhibited high selectivity, sensitivity, and rapid response toward UO22+. Besides, we have successfully employed RU to visualize UO22+ in the blood of mice's eyeballs for the first time, providing a valuable method to investigate its biological behavior and toxicity in living system.

Carbon monoxide (CO) is an essential signaling molecule in the human body, and CO imaging is vital for understanding related pathophysiological mechanisms. Herein, we introduce Nile-CO, a novel near-infrared (NIR) fluorescent probe based on the Nile blue fluorophore. Nile-CO exhibits high selectivity, sensitivity, and a rapid response time of less than 5 min, with a turn-on fluorescence signal at 664 nm. Targeting mitochondria, the probe enables imaging of both endogenous and exogenous CO in HeLa cells. Moreover, in a lipopolysaccharide (LPS)-induced mouse inflammation model, Nile-CO effectively tracks CO fluctuations during acute inflammation and allows direct detection of CO levels in eyeball blood samples, highlighting its potential for practical applications in CO-related research.

Acetylcholinesterase (AChE) plays a vital role in various neurological diseases including brain disorders, neurotransmission alterations, and cancer. Developing effective methods to image AChE in biological samples is essential for understanding its mechanisms in biosystems. Here, we introduce a novel fluorescent probe CNA, that enables detection of AChE at 520 nm with rapid response time of 60 s and a detection limit of 0.014 U/mL. We successfully applied CNA to image endogenous and exogenous AChE in PC12 cells and in living mice. These findings highlight the potential of CNA as an effective method to study the physiological and pathological roles of AChE in complex living systems.

Genetic transformation is a crucial tool for investigating gene function and advancing molecular breeding in crops, with Agrobacterium tumefaciens-mediated transformation being the primary method for plant genetic modification. However, this approach exhibits significant genotypic dependence in maize. Therefore, to overcome these limitations, we combined dynamic transcriptome analysis and genome-wide association study (GWAS) to identify the key genes controlling Agrobacterium infection frequency (AIF) in immature maize embryos. Transcriptome analysis of Agrobacterium-infected embryos uncovered 8483 and 1580 genotype-specific response genes in the maize line 18-599R with low AIF and A188 with high AIF, respectively. A weighted gene co-expression network analysis (WGCNA) revealed five and seven stage-specific co-expression modules in each corresponding line. Based on a self-developed AIF quantitation method, the GWAS revealed 30 AIF-associated single-nucleotide polymorphisms and 315 candidate genes under multiple environments. Integration of GWAS and WGCNA further identified 12 key genes associated with high AIF in A188. ZmHRGP, encoding a hydroxyproline-rich glycoprotein, was functionally validated as a key factor of AIF in immature embryos. Knockout of ZmHRGP enabled us to establish a high-efficiency genetic transformation system for the 18-599R line, with the transformation frequency being approximately 80%. Moreover, the transient reduction of ZmHRGP expression significantly enhanced the AIF of maize calluses and leaves. Collectively, these findings advance our understanding of plant factors controlling Agrobacterium infection and contribute to developing more efficient Agrobacterium-mediated transformation systems in crops.

In this study, we introduced a novel fluorescent probe RNP, which demonstrated outstanding sensitivity and specificity for phosgene detection. Upon phosgene exposure, the probe exhibited rapid fluorescence turn-on within a short re-sponse time (6 s). RNP was also effective in both cellular and murine experiments, where fluorescence enhancement was observed in the respiratory tract of mice.

Genetic transformation is a crucial tool for investigating gene function and advancing molecular breeding in crops, with Agrobacterium tumefaciens-mediated transformation being the primary method for plant genetic modification. However, this approach exhibits significant genotypic dependence in maize. Therefore, to overcome these limitations, we combined dynamic transcriptome analysis and genome-wide association study (GWAS) to identify the key genes controlling Agrobacterium infection frequency (AIF) in immature maize embryos. Transcriptome analysis of Agrobacterium-infected embryos uncovered 8483 and 1580 genotype-specific response genes in the maize line 18-599R with low AIF and A188 with high AIF, respectively. A weighted gene co-expression network analysis (WGCNA) revealed five and seven stage-specific co-expression modules in each corresponding line. Based on a self-developed AIF quantitation method, the GWAS revealed 30 AIF-associated single-nucleotide polymorphisms and 315 candidate genes under multiple environments. Integration of GWAS and WGCNA further identified 12 key genes associated with high AIF in A188. ZmHRGP, encoding a hydroxyproline-rich glycoprotein, was functionally validated as a key factor of AIF in immature embryos. Knockout of ZmHRGP enabled us to establish a high-efficiency genetic transformation system for the 18-599R line, with the transformation frequency being approximately 80%. Moreover, the transient reduction of ZmHRGP expression significantly enhanced the AIF of maize calluses and leaves. Collectively, these findings advance our understanding of plant factors controlling Agrobacterium infection and contribute to developing more efficient Agrobacterium-mediated transformation systems in crops.

Gibberella ear rot (GER) in maize caused by Fusarium graminearum is one of the most devastating maize diseases reducing grain yield and quality worldwide. The genetic bases of maize GER resistance remain largely unknown. Using artificial inoculation across multiple environments, the GER severity of an association panel consisting of 316 diverse inbred lines was observed with wide phenotypic variation. In the association panel, a genome-wide association study using a general linear model identified 69 single-nucleotide polymorphisms (SNPs) significantly associated with GER resistance at the threshold of 2.04 × 10−5, and the average phenotypic variation explained (PVE) of these SNPs was 5.09%. We also conducted a genome-wide association study analysis using a mixed linear model at a threshold of 1.0 × 10−4, and 16 significantly associated SNPs with an average PVE of 4.73% were detected. A combined general linear model and mixed linear model method obtained 10 co-localized significantly associated SNPs linked to GER resistance, including the most significant SNP (PZE-105079915) with the greatest PVE value, 9.07%, at bin 5.05 following 10 candidate genes. These findings are significant for the exploration of the complicated genetic variations in maize GER resistance. The regions and genes identified herein provide a list of candidate targets for further investigation, in addition to the elite germplasm resources that can be used for breeding GER resistance in maize.

Gibberella ear rot (GER) caused by Fusarium graminearum (teleomorph Gibberella zeae) is one of the most devastating maize diseases that reduces grain yield and quality worldwide. Utilization of host genetic resistance has become one of the most suitable strategies to control GER. In this study, a set of 246 diverse inbred lines derived from the intermated B 73 × Mo 17 doubled haploid population (IBM Syn10 DH) were used to detect quantitative trait loci (QTL) associated with resistance to GER. Meanwhile, a GradedPool-Seq (GPS) approach was performed to identify genomic variations involved in GER resistance. Using artificial inoculation across multiple environments, GER severity of the population was observed with wide phenotypic variation. Based on the linkage mapping, a total of 14 resistant QTLs were detected, accounting for 5.11 to 14.87% of the phenotypic variation, respectively. In GPS analysis, five significant single nucleotide polymorphisms (SNPs) associated with GER resistance were identified. Combining QTL mapping and GPS analysis, a peak-value SNP on chromosome 4 from GPS was overlapped with the QTL qGER4.2, suggesting that the colocalized region could be the most possible target location conferring resistance to GER. Subsequently, seven candidate genes were identified within the peak SNP, linking them to GER resistance. These findings are useful for exploring the complicated genetic variations in maize GER resistance. The genomic regions and genes identified herein provide a list of candidate targets for further investigation, in addition to the combined strategy that can be used for quantitative traits in plant species.

Iron-based catalysts with high load content of iron sulfide (FeS) were commonly peroxymonosulfate (PMS) and hydrogen peroxide (H2O2) activators to degrade organic pollutants but limited catalytic efficiency and increased risk of ferrous ion leaching restricted their use. Meanwhile, various biomass materials such as straw, peel, and branch have been extensively prepared into biochar for mechanical support for iron-based catalysts; however, the preparation process of biochar was energy-intensive. In this study, FeS nanoparticles modified rape straw composites (RS–FeS) encapsulated with ethylenediaminetetraacetic acid (RS–EDTA–FeS) were successfully presented by in-situ synthesis method for efficiently activating PMS and H2O2 to degrade oxytetracycline (OTC), which was economical and environmentally friendly. The results showed that the modified rape straw can remove OTC efficiently, and the addition of EDTA also significantly enhanced the stability and the reusability of the catalyst. In addition, EDTA also promoted the activation of H2O2 at neutral pH. The OTC degradation efficiency of the two catalysts by PMS was faster than that of H2O2, but H2O2 had a stronger ability to remove OTC than PMS. The highest OTC removal efficiency of RS–FeS and RS–EDTA–FeS were 87.51 and 81.15%. O2•– and 1O2 were the major reactive oxidative species (ROS) in the PMS system. Furthermore, compared with RS–FeS, the addition of EDTA inhabited the generation of O2•– in the PMS system. Instead, O2•– and •OH were the major ROS in the H2O2 system, but 1O2 was also identified in RS–FeS/H2O2 system. RS–EDTA–FeS showed a trend of rising first and then decreasing in recycle test. Instead, the removal rate of OTC by RS–FeS decreased significantly with the increase in reuse times. In the actual wastewater test, the TOC removal of two catalysts active by H2O2 was better than PMS, which was consistent with the test results of OTC, indicating that the two catalysts have application value in the removal of organic pollutants in actual wastewater. This study directly used plant materials as catalysts and omits the preparation process of biochar, greatly reduces the preparation cost and secondary pollution of catalysts, and provides theoretical support for the deepening of advanced oxidation technology.

As a biomass waste, rape straw shows a good application prospect in heterogeneous catalyst preparation due to its low-cost and stable structure. In this study, FeS-modified rape straw (RS-FeS) and its biochar (RSBC-FeS) were firstly synthesized to remove oxytetracycline (OTC). The highest OTC removal capacities observed for RS-FeS and RSBC-FeS were 635.66 and 827.80 mg g–1. When compared with the adsorption process, the degradation ratios of the total OTC removal capacity observed in the RS-FeS/H2O2 and RSBC-FeS/H2O2 systems were 70.14 and 79.35%. Degradation was the dominant process observed during the removal of OTC. Both radical (SO4•–, •OH, and O2•–) and non-radical (1O2 and Ov) pathways were involved in the degradation process. OTC was degraded into smaller molecules via hydroxylation, dehydration, quinonization, demethylation, decarbonylation, alcohol oxidation, and ring cleavage reaction, indicating two catalysts could efficiently mineralize organic pollutants. The highest total organic carbon removal efficiencies of observed for RS-FeS and RSBC-FeS in swine wastewater were 88.93 and 96.81%, respectively. In addition, OTC removal efficiency of RS-FeS was more than 80% in successive experiments, further suggesting the feasibility of rape straw to Fenton-like catalysts. In this study, FeS nanoparticles were directly loaded on rape straw for the first time. Compared with biochar, FeS-modified rape straw can also degrade OTC efficiently, which provides an eco-friendly, high-efficient, and sustainable strategy for the preparation of catalyst.

Leaf color mutant is an important resource for studying chlorophyll biosynthesis and chloroplast development in maize. Here, a novel mutant zebra crossband 9 (zb9) with transverse green-/yellow-striped leaves appeared from ten-leaf stage until senescence was identified from mutant population derived from the maize inbred line RP125. The yellow section of the zb9 mutant displays a reduction of chlorophyll and carotenoid contents, as well as impaired chloroplast structure. Genetic analysis showed that the zb9 mutant phenotype was caused by a single recessive gene. Map-based cloning demonstrated that the zb9 locus was delimited into a 648 kb region on chromosome 1 covering thirteen open reading frames (ORFs). Among them, a point mutation (G to A) in exon 2 of the gene Zm00001d029151, named Zmzb9, was identified based on sequencing analysis. The causal gene Zmzb9 encodes UDP-glucose-4-epimerase 4 (UGE4), a key enzyme involved in chloroplast development and was considered as the only candidate gene controlling the mutant phenotype. Expression patterns indicated that the causal gene was abundantly expressed in the leaves and sheaths, as well as significantly downregulated in the mutant compared to that in the wild type. Subcellular localization showed that ZmZB9 was localized in chloroplasts and implied the putative gene involved in chloroplast development. Taken together, we propose that the causal gene Zmzb9 tightly associated with the zebra leaf phenotype, and the obtained gene here will help to uncover the regulatory mechanism of pigment biosynthesis and chloroplast development in maize.

SummaryKernel size‐related traits are the most direct traits correlating with grain yield. The genetic basis of three kernel traits of maize, kernel length (KL), kernel width (KW) and kernel thickness (KT), was investigated in an association panel and a biparental population. A total of 21 single nucleotide polymorphisms (SNPs) were detected to be most significantly (P < 2.25 × 10−6) associated with these three traits in the association panel under four environments. Furthermore, 50 quantitative trait loci (QTL) controlling these traits were detected in seven environments in the intermated B73 × Mo17 (IBM) Syn10 doubled haploid (DH) population, of which eight were repetitively identified in at least three environments. Combining the two mapping populations revealed that 56 SNPs (P < 1 × 10−3) fell within 18 of the QTL confidence intervals. According to the top significant SNPs, stable‐effect SNPs and the co‐localized SNPs by association analysis and linkage mapping, a total of 73 candidate genes were identified, regulating seed development. Additionally, seven miRNAs were found to situate within the linkage disequilibrium (LD) regions of the co‐localized SNPs, of which zma‐miR164e was demonstrated to cleave the mRNAs of Arabidopsis CUC1, CUC2 and NAC6 in vitro. Overexpression of zma‐miR164e resulted in the down‐regulation of these genes above and the failure of seed formation in Arabidopsis pods, with the increased branch number. These findings provide insights into the mechanism of seed development and the improvement of molecular marker‐assisted selection (MAS) for high‐yield breeding in maize.

A dual-mode method was developed for the determination of ascorbic acid (AA) and of ascorbic acid oxidase (AA-Ox) activity. It combines the advantages of ratiometric fluorometry and colorimetry. The assay is based on the oxidation of o-phenylenediamine (OPDA) by permanganate (KMnO4). A yellow substance (referred to as oxOPDA) with an absorption peak at 425 nm is rapidly produced in the presence of the oxidant. oxOPDA reduces the blue fluorescence of carbon dots (C-dots) peaking at 450 nm (upon 380-nm excitation), and a new emission peak is found at 565 nm. If AA is pesent, it consumes a certain fraction of KMnO4, so that less OPDA will be oxidized. This is accompanied by a decrease in the intensity of the fluorescence at 565 nm and an increase in the intensity at 450 nm. In parallel, the color of the solution changes from yellow to colorless. The determination of the activity of ascorbic acid oxidase (AA-Ox) is performed as follows: AA is oxidized by AA-Ox. This causes the fluorescence and colors to change in the opposite directions compared with AA detection. The ratio of fluorescences (I565/I450) becomes larger if the color the solution turns from colorless to yellow. Thus, the fluorescence intensity ratio (I565/I450) and colorimetric “bare-eye” readout can be used for determination of both the concentration of AA and the activity of AA-Ox. The fluorometric assay for AA has a linear range that extends from 0.6 to 40 μM, and the colorimetric assay from 0.2 to 70 μM. The respective data for AA-Ox activity are 0.04 ~ 5 mU·mL−1 and 0.04 ~ 8 mU·mL−1, respectively. The limits of detection for AA are 9 and 40 nM, and the LODs for AA-Ox activity are 0.017 and 0.012 mU·mL−1.

Background: Bromodomain-containing protein 4 (BRD4) inhibitors synthesized with trimethoxy-ring refer to a new series of small molecular inhibitors. Currently, BRD4 offers the potential for research as a cancer therapeutic target. Based on previous studies, 17 trimethoxy-ring derivatives were designed as novel BRD4 inhibitors. Methods: All these new compounds were synthesized via the amide reaction. Their structures were identified by 1H NRM, 13C NRM spectra and HRMS. In vitro antitumor activities of the new compounds were evaluated by MTT. Molecular docking studies were conducted to explain the binding interactions of these compounds with BRD4 protein. Results: A series of novel trimethoxy-ring derivatives were synthesized as BRD4 inhibitors and screened by testing their inhibition against HCT116, MCF-7, K562 and KMS-1 cell lines. Most of the newly synthesized compounds exhibited moderate-to-good inhibitory activity against HCT116, MCF-7, and K562 cell lines, whereas some showed inhibitory activity against the KMS-1 cell line. Conclusion: Compound 3g demonstrated the most potent anti-tumor activity against breast (MCF-7), leukemia (K562), multiple myeloma (KMS-1), and colon cancer (HCT116) cell lines.

A dual-read detection system is described for non-enzymatic and non-aggregation based analysis of uric acid (UA). Silver triangular nanoprisms (AgTNPs) were used as colorimetric probes, while the reduction in the fluorescence of nitrogen-doped carbon quantum dots (N-CQDs) served as the fluorometric readout. The absorption band of the AgTNPs overlaps the emission band of N-CQDs (with a peak at 440 nm). Therefore, fluorescence is reduced owing to an inner filter effect. The AgTNPs are etched if exposed to H2O2, and round nanodiscs are formed. In the presence of UA, etching of the AgTNPs is suppressed because the facets of the AgTNPs are coated with UA. The absorbance, best measured at 683 nm, increases with the concentration of the pre-added UA. The colorimetric assay works in the 0.1–45 μM UA concentration range, and the fluorometric assay between 1 and 42 μM of UA. The respective detection limits are 50 and 200 nM, respectively. The probe can be used for direct visualization of UA. The method was successfully applied to the determination of UA in urine samples.

The paper describes an optical probe for colorimetric and fluorometric determination of protamine. The probe consists of a mixture of carbon quantum dots (CQDs) and gold nanoparticles (AuNPs) where the CQDs (with excitation/emission peaks at 350/440 nm) serve as fluorescent reporter and the AuNPs serve as a colorimetric reporter and a quencher of the fluorescene of CQDs. The nanoparticles applied here are characterized by high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), time correlated single photon counting (TCSPC), UV-vis and fluorescence spectroscopy, dynamic lights scattering (DLS) and zeta potentials. The green fluorescence of the CQDs overlaps the red absorption of AuNPs (520 nm) and therefore is quenched after fluorescence resonance energy transfer (FRET) between CQDs and AuNPs. Protamine is rich in basic arginine residues which are positively charged at physiological pH values. Protamine therefore can induce the aggregation of AuNPs which is accompanied by a color change from red to blue. Hence, the fluorescence of CQDs no longer overlaps the absorption of (aggregated) AuNPs (650 nm) and is not quenched as a result. These findings form the basis for a fluorometric assay that has linear response in the 10–220 ng·mL−1 protamine concentration range, with a 1.2 ng·mL−1 lower detection limit. The respective values for the colorimetric assay are 20–160 ng·mL−1 and 2 ng·mL−1. This dual-signal probe also possesses excellent selectivity for protamine and in our perception has a large potential for the determination of protamine in serum.

An analysis of the effect of ENSO events with different strengths on the isotopic composition of precipitation is conducted based on test data for 206 precipitation samples collected from January 2012 to February 2017 in Shanghai coupled with the archives for Nanjing, Wuhan, Fuzhou, and Hong Kong from 1961 to 2012 from the Global Network of Isotopes in Precipitation (GNIP) database. During the research periods, the δD and δ18O values in precipitation are lower in summer and autumn but higher in winter and spring. The slope and intercept of the atmospheric precipitation lines during El Niño events are larger than during other times, while anti-temperature, precipitation amount, and vapor pressure effects are more significant than during La Niña events. The δ18O and deuterium excess values (value of d) of rainfall in Shanghai during El Niño and La Niña events of varied strengths have an obvious negative correlation with the oceanic Niño index (ONI), sea surface temperature anomaly (SSTA), and the extreme and cumulative values of ONI. Moreover, ENSO events are closely intertwined with the correlation between δ18O isotopic value in precipitation, ONI, and SSTA.

This work established a fluorescence approach for detecting ascorbic acid (AA) based on Cu-ZnCdS quantum dots (Cu-ZnCdS QDs) and α-MnO2 nanorods. Cu-ZnCdS QDs and α-MnO2 nanorods were characterized by high-resolution transmission electron microscopy (HRTEM), fluorescence spectroscopy, inductively coupled plasma optical emission spectroscopy (ICP-OES) and X-ray diffraction (XRD). In the presence of α-MnO2 nanorods, the fluorescence of Cu-ZnCdS QDs was greatly quenched through the inner filter effect (IFE). Subsequently, AA can trigger the decomposition of the α-MnO2 nanorods which can reduce α-MnO2 to Mn2+ and recover the fluorescence. Under optimal conditions, a linear relation was obtained over the range 5.02−401.77 μM with a 31.62 μM detection limit. Through applying the fluorescent sensing system for detecting AA, a satisfactory result is obtained with recoveries ranging from 89.23% to 110.99%.

We report the synthesis of a simple pyrene derivative and its application in protamine detection and monitoring of trypsin activity. This assay can be conducted in aqueous solution and features rapid response, visual detection, high sensitivity and selectivity. The limit of detection of protamine was 0.5 μg mL(-1). The IC50 value of a soybean trypsin inhibitor was estimated to be 0.51 U mL(-1).