Regioselective N-Trideuteromethylation of Tautomeric Polyaza Heterocycles.

Methods for regioselective N-trideuteromethylation of tautomeric polyaza heterocycles are highly sought-after. Disclosed herein is an N-trideuterated methylation reaction of imidazoles and pyrazoles with high regioselectivity and deuterium purity using easily available CF3SO3CD3 as the -CD3 source. This method enables the easy synthesis of important deuterium-labeled azoles, including dimetridazole-d3, ipronidazole-d3, hydroxy dimetridazole-d3, and ronidazole-d3.

Loss of function of OsL1 gene cause early flowering in rice under short-day conditions.

Heading date is one of the important agronomic traits that affects rice yield. In this study, we cloned a new rice B3 family gene, OsL1, which regulates rice heading date. Importantly, osl1-1 and osl1-2, two different types of mutants of OsL1 were created using the gene editing technology CRISPR/Cas9 system and exhibited 4 days earlier heading date than that of the wild type under short-day conditions. Subsequently, the plants overexpressing OsL1, OE-OsL1, showed a 2-day later heading date than the wild type in Changsha and a 5-day later heading date in Lingshui, but there was no significant difference in other yield traits. Moreover, the results of subcellular localization study indicated that OsL1 protein was located in the nucleus and the expression pattern analysis showed that OsL1 gene was expressed in rice roots, stems, leaves, and panicles, and the expression level was higher at the root and weak green panicle. In addition, the OsL1 gene was mainly expressed at night time under short-light conditions. The transcriptomic analysis indicated that OsL1 might be involved in the Hd1-Hd3a pathway function. Together, our results revealed that the cloning and functional analysis of OsL1 can provide new strategy for molecular design breeding of rice with suitable fertility period. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-024-01444-1.

A Radical Pathway and Stabilized Li Anode Enabled by Halide Quaternary Ammonium Electrolyte Additives for Lithium-Sulfur Batteries.

Passivation of the sulfur cathode by insulating lithium sulfide restricts the reversibility and sulfur utilization of Li-S batteries. 3D nucleation of Li2 S enabled by radical conversion may significantly boost the redox kinetics. Electrolytes with high donor number (DN) solvents allow for tri-sulfur (S3 ⋅- ) radicals as intermediates, however, the catastrophic reactivity of such solvents with Li anodes pose a great challenge for their practical application. Here, we propose the use of quaternary ammonium salts as electrolyte additives, which can preserve the partial high-DN characteristics that trigger the S3 ⋅- radical pathway, and inhibit the growth of Li dendrites. Li-S batteries with tetrapropylammonium bromide (T3Br) electrolyte additive deliver the outstanding cycling stability (700 cycles at 1 C with a low-capacity decay rate of 0.049 % per cycle), and high capacity under a lean electrolyte of 5 µLelectrolyte mgsulfur -1 . This work opens a new avenue for the development of electrolyte additives for Li-S batteries.

EMBRYO SAC DEVELOPMENT 1 affects seed setting rate in rice by controlling embryo sac development.

Seed setting rate is one of the critical factors that determine rice yield. Grain formation is a complex biological process, whose molecular mechanism is yet to be improved. Here we investigated the function of an OVATE family protein, Embryo Sac Development 1 (ESD1), in the regulation of seed setting rate in rice (Oryza sativa) by examining its loss-of-function mutants generated via clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated9 (Cas9) technology. ESD1 was predominantly expressed at Stage 6 of panicle development, especially in the ovules. esd1 mutants displayed reduced seed setting rates with normal stamen development and pollen tube growth but abnormal pistil group. Investigation of embryo sacs revealed that during the mitosis of functional megaspores, some egg cells degraded during differentiation in esd1 mutants, thereby hindering subsequent fertilization process and reducing seed setting rate. In addition, the transcriptional level of O. sativa anaphase-promoting complex 6, a reported embryo sac developing gene, was significantly reduced in esd1 mutants. These results support that ESD1 is an important modulator of ESD and seed setting rate in rice. Together, this finding demonstrates that ESD1 positively regulates the seed setting rate by controlling ESD in rice and has implications for the improvement of rice yield.

A novel strategy for creating a new system of third-generation hybrid rice technology using a cytoplasmic sterility gene and a genic male-sterile gene.

Heterosis utilization is the most effective way to improve rice yields. The cytoplasmic male-sterility (CMS) and photoperiod/thermosensitive genic male-sterility (PTGMS) systems have been widely used in rice production. However, the rate of resource utilization for the CMS system hybrid rice is low, and the hybrid seed production for the PTGMS system is affected by the environment. The technical limitations of these two breeding methods restrict the rapid development of hybrid rice. The advantages of the genic male-sterility (GMS) rice, such as stable sterility and free combination, can fill the gaps of the first two generations of hybrid rice technology. At present, the third-generation hybrid rice breeding technology is being used to realize the application of GMS materials in hybrid rice. This study aimed to use an artificial CMS gene as a pollen killer to create a smart sterile line for hybrid rice production. The clustered regularly interspaced short palindromic repeats/CRISPR-associated 9 (CRISPR/Cas9) technology was used to successfully obtain a CYP703A3-deficient male-sterile mutant containing no genetically modified component in the genetic background of indica 9311. Through young ear callus transformation, this mutant was transformed with three sets of element-linked expression vectors, including pollen fertility restoration gene CYP703A3, pollen-lethality gene orfH79 and selection marker gene DsRed2. The maintainer 9311-3B with stable inheritance was obtained, which could realize the batch breeding of GMS materials. Further, the sterile line 9311-3A and restorer lines were used for hybridization, and a batch of superior combinations of hybrid rice was obtained.

OsMSR3, a Small Heat Shock Protein, Confers Enhanced Tolerance to Copper Stress in Arabidopsis thaliana.

Copper is a mineral element essential for the normal growth and development of plants; however, excessive levels can severely affect plant growth and development. Oryza sativa L. multiple stress-responsive gene 3 (OsMSR3) is a small, low-molecular-weight heat shock protein (HSP) gene. A previous study has shown that OsMSR3 expression improves the tolerance of Arabidopsis to cadmium stress. However, the role of OsMSR3 in the Cu stress response of plants remains unclear, and, thus, this study aimed to elucidate this phenomenon in Arabidopsis thaliana, to further understand the role of small HSPs (sHSPs) in heavy metal resistance in plants. Under Cu stress, transgenic A. thaliana expressing OsMSR3 showed higher tolerance to Cu, longer roots, higher survival rates, biomass, and relative water content, and accumulated more Cu, abscisic acid (ABA), hydrogen peroxide, chlorophyll, carotenoid, superoxide dismutase, and peroxidase than wild-type plants did. Moreover, OsMSR3 expression in A. thaliana increased the expression of antioxidant-related and ABA-responsive genes. Collectively, our findings suggest that OsMSR3 played an important role in regulating Cu tolerance in plants and improved their tolerance to Cu stress through enhanced activation of antioxidative defense mechanisms and positive regulation of ABA-responsive gene expression.

An anther development F-box (ADF) protein regulated by tapetum degeneration retardation (TDR) controls rice anther development.

MAIN CONCLUSION: In this study, we reported that a F-box protein, OsADF, as one of the direct targets of TDR , plays a critical role in rice tapetum cell development and pollen formation. The tapetum, the innermost sporophytic tissue of anther, plays an important supportive role in male reproduction in flowering plants. After meiosis, tapetal cells undergo programmed cell death (PCD) and provide nutrients for pollen development. Previously we showed that tapetum degeneration retardation (TDR), a basic helix-loop-helix transcription factor, can trigger tapetal PCD and control pollen wall development during anther development. However, the comprehensive regulatory network of TDR remains to be investigated. In this study, we cloned and characterized a panicle-specific expression F-box protein, anther development F-box (OsADF). By qRT-PCR and RNA in situ hybridization, we further confirmed that OsADF expressed specially in tapetal cells from stage 9 to stage 12 during anther development. In consistent with this specific expression pattern, the RNAi transgenic lines of OsADF exhibited abnormal tapetal degeneration and aborted microspores development, which eventually grew pollens with reduced fertility. Furthermore, we demonstrated that the TDR, a key regulator in controlling rice anther development, could regulate directly the expression of OsADF by binding to E-box motifs of its promoter. Therefore, this work highlighted the possible regulatory role of TDR, which regulates tapetal cell development and pollen formation via triggering the possible ADF-mediated proteolysis pathway.

[Screening and confirmation of copper chlorophyll adulteration in olive oils].

OBJECTIVE: To develop a qualitative screening method by high performance liquid chromatograph-photo-diode array (HPLC-PDA) and a confirmation method by ultra performance liquid chromatograph-quadrupole-time of flight mass spectrometry (UPLC-Qtof-MSMS) for Copper Chlorophyll in olive oils. METHODS: Commercial liposoluble copper chlorophyll diluted by petroleum ether was purified and concentrated by sep-pak silica solid-phase extraction (SPE) cartridges, the injection was separated by symmetry shield RP18 column, and detected by the PDA at the wavelength 430 nm. The injection was separated by ACQUITY UPLC BEH (18)C and determined by UPLC-Qtof-MSMS in negative atmospheric pressure chemical ionization mode, then confirmed by the exact mass of parent ion and secondary fragment ion provided by the mass spectrum. Samples from supermarket were screened for Cu-pyropheophytin a by established method. RESULTS: Cu-pyropheophytin a could be used for discrimination as indicative compound whether the olive oils were mixed with copper chlorophyll. 25 samples including olive oil, soybean oil and spirulina from supermarket were screened, Cu-pyropheophytin a was found in one type of olive oil. CONCLUSION: This method could be used for screening and qualitative analysis of Copper Chlorophyll in olive oils for its accuracy , reliability and excellent specificity.

[Determination of dimethyl fumarate in bakery food by d-SPE-HPLC-PDA].

OBJECTIVE: To establish a simple and rapid pretreatment method with dispersive solid phase extraction ( d-SPE) by HPLC for determination of dimethyl fumarate in bakery foods. METHODS: Dimethyl fumarate in samples was ultrasonically extracted by methanol, and cleaned up with d-SPE. Then, it was separated on C18 chromatographic column (4.6 mm x 25 mm, 5 µm) with a mixture of methanol--0.03 mol/L sodium acetate and 0.008 mol/L tetrabutyl ammonium bromide (40: 60, V/V) as mobile phase. The photodiode array detector was used in the determination under λ = 220 nm. RESULTS: In the linear range of 0.1 -25 µg/ml, the correlation coefficients was r > 0.999, and the average recoveries of the spiked samples were in the range of 82.8% - 107.5% with relative standard deviations (RSD) in the range of 3.30% - 7.30% (n = 6). The limit of detection ( LOD) was 0.4 mg/kg, and the limit of quantification was 1.0 mg/kg. CONCLUSION: The method is simple, rapid, sensitive and accurate, and suitable for determine dimethyl fumarate in bakery foods.

Structural variations of a new fertility restorer gene, Rf20, underlie the restoration of wild abortive-type cytoplasmic male sterility in rice.

The discovery of a wild abortive-type cytoplasmic male sterile line and the breeding of its restorer line have led to the commercialization of three-line hybrid rice, which has contributed greatly to global food security. However, the molecular mechanisms underlying fertility abortion and the restoration of wild abortive-type cytoplasmic male sterile lines largely remain elusive. In this study, we cloned a restorer gene, Rf20, following a genome-wide association study analysis of the core parent lines of three-line hybrid rice. We found that Rf20 was present in all core parental lines, but different haplotypes and structural variants of its gene resulted in differences in Rf20 expression levels between sterile and restored lines. Rf20 could restore fertility in the wild abortive-type cytoplasmic male sterile line and was found to be responsible for fertility restoration in some cytoplasmic male sterile lines under high temperature. In addition, we found that Rf20 encodes a pentatricopeptide repeat protein that competes with WA352 for binding with COX11. This interaction enhances COX11's function as a scavenger of reactive oxygen species, which in turn restores pollen fertility. In this study, a new model of pentatricopeptide repeat proteins involved in the fertility recovery of cytoplasmic male sterile lines was proposed, which provides an important theoretical basis for the breeding of strong restorer lines and for overcoming high-temperature fertility recovery of some three-line sterile lines.

[Study on melamine migration rules in products of tripolycyanamide for food packaging].

OBJECTIVE: To study the migration rules of melamine in products of tripolycyanamide for food packaging. METHODS: With different stimulant solutions, temperatures exposure and long term use, the migration quantities of melamine in products of tripolycyanamide for food packaging into 3% acetic acid and 15% ethanol were measured by HPLC method. RESULTS: The amounts of melamine migrated to 3% acetic acid was higher than those to 15% ethanol. Higher temperatures more amounts of melamine of products of tripolycyanamide were migrated. With the higher temperature exposure was done, the amount of melamine migration reached maximum in lower number of repeated exposures. After 10 times of migration tests, melamine still can be migrated but the amount was not high. The single maximum migration amount was 0. 0851 mg/dm2, and the value was approximately 1/59 of the SML regulated by EU regulations. CONCLUSION: 3% acetic acid is the most serious solvent. The higher the temperature, the greater the migration, and melamine still migrate after repeated use.

Joint analysis of phenotype-effect-generation identifies loci associated with grain quality traits in rice hybrids.

Genetic improvement of grain quality is more challenging in hybrid rice than in inbred rice due to additional nonadditive effects such as dominance. Here, we describe a pipeline developed for joint analysis of phenotypes, effects, and generations (JPEG). As a demonstration, we analyze 12 grain quality traits of 113 inbred lines (male parents), five tester lines (female parents), and 565 (113×5) of their hybrids. We sequence the parents for single nucleotide polymorphisms calling and infer the genotypes of the hybrids. Genome-wide association studies with JPEG identify 128 loci associated with at least one of the 12 traits, including 44, 97, and 13 loci with additive effects, dominant effects, and both additive and dominant effects, respectively. These loci together explain more than 30% of the genetic variation in hybrid performance for each of the traits. The JEPG statistical pipeline can help to identify superior crosses for breeding rice hybrids with improved grain quality.

The hepatoprotective effect of aspirin on carbon tetrachloride­induced hepatic fibrosis via inhibition of TGFß­1 pathway and pro­inflammatory cytokines IL­1ß and COX­2 in rats.

Aspirin decreases liver fibrosis index and inflammation levels. However, the exact mechanism underlying the effects of aspirin are yet to be elucidated. The aim of the study was to investigate the potential protective effects of aspirin on carbon tetrachloride (CCl4)-induced hepatic fibrosis in Sprague-Dawley rats. Rats were divided into four groups, including healthy and CCl4 control and low-(aspirin 10 mg/kg + CCl4) and high-dose aspirin group (aspirin 300 mg/kg + CCl4). After 8 weeks treatment, the histopathological examinations of hepatocyte fibrosis in liver and serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), IL-1ß, transforming growth factor-ß1 (TGF-ß1), hyaluronic acid (HA), laminin (LN) and type IV collagen (IV.C) were determined. Histopathological examination suggested that aspirin decreased CCl4-induced hepatic fibrosis and liver inflammation. The high-dose aspirin group significantly decreased the serum levels of ALT, AST, HA and LN compared with the CCl4 control group. High-dose aspirin group significantly decreased the levels of pro-inflammatory cytokines IL-1ß compared with CCl4 group. The high-dose aspirin group significantly inhibited the expression of TGFß-1 protein compared with CCl4 group. Overall, the present study indicated that aspirin exhibited potent protective effects against CCl4-induced hepatic fibrosis via inhibition of the TGFß-1 pathway and pro-inflammatory cytokine IL-1ß.

Solid electrolytes for solid-state Li/Na-metal batteries: inorganic, composite and polymeric materials.

The thrust towards a higher energy density and safer alternative to traditional-liquid-electrolyte-based batteries has driven academic and industrial efforts in developing solid-state batteries and particularly solid-state Li/Na-metal batteries (SSLMBs/SSNMBs). Despite research on solid electrolytes seemingly being on a perpetual trajectory, there have been considerable critical issues to be overcome for solid electrolytes, including the insufficient ionic conductivity, low ion-transference number, and poor compatibility with lithium-metal anodes and intercalation cathodes. This feature article sets out efforts to regulate the cubic structure of garnet-type electrolytes, along with a discussion of the solid-solution synthetic approach to produce garnet-type and NASICON (sodium super ion conductor)-type electrolytes, followed by the synthetic strategy for sintering dense nano-grained NASICON-type electrolytes. Next, the mechanochemical synthetic approach and hybrid electrolyte design strategy to mitigate the issues associated with PEO-based composite electrolytes are presented. Finally, the advancement of promising polymeric electrolytes is discussed. We end the perspective with an opinion on the future research in this area.

Segmental Motion Adjustment of the Polycarbonate Electrolyte for Lithium-Metal Batteries.

Carbonyl oxygen atoms are the primary active sites to solvate Li salts that provide a migration site for Li ions conducting in a polycarbonate-based polymer electrolyte. We here exploit the conductivity of the polycarbonate electrolyte by tuning the segmental motion of the structural unit with carbonyl oxygen atoms, while its correlation to the mechanical and electrochemical stability of the electrolyte is also discussed. Two linear alkenyl carbonate monomers are designed by molecular engineering to combine methyl acrylate (MA) and the commonly used ethylene carbonate (EC), w/o dimethyl carbonate (DMC) in the structure. The integration of the DMC structural unit in the side chain of the in situ constructed polymer (p-MDE) releases the free motion of the terminal EC units, which leads to a lower glass-transition temperature and higher ionic conductivity. While pure polycarbonates are normally fragile with high Young's modulus, such a prolonged side chain also manipulates the flexibility of the polymer to provide a mechanical stable interface for Li-metal anode. Stable long-term cycling performance is achieved at room temperature for both LiFePO4 and LiCoO2 electrodes based on the p-MDE electrolyte incorporated with a solid plasticizer.

Occurrence and Risk Assessment of Fluoroquinolone Residues in Chicken and Pork in China.

Antibiotics, especially fluoroquinolones, have been exhaustively used in animal husbandry. However, very limited information on the occurrence and exposure assessment of fluoroquinolone residues in chicken and pork in China is available to date. Thus, a total of 1754 chicken samples and 1712 pork samples were collected from 25 provinces in China and tested by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for residual determination of six common fluoroquinolones. The results revealed that the detection frequencies of fluoroquinolone residues were 3.99% and 1.69% in chicken and pork samples. The overall violation frequencies were 0.68% and 0.41% for chicken and pork. Enrofloxacin and its metabolite ciprofloxacin were found to be the most predominant fluoroquinolones. The occurrence of these antibiotics in different sampling regions and market types was analyzed. The %ADI values of enrofloxacin and ciprofloxacin were far less than 100, indicating the health risk associated with the exposure to these aforementioned fluoroquinolone residues via chicken and pork for Chinese children, adolescents, and adults was acceptable. The results provided useful references for Chinese consumers, and helped to appropriately use these antibiotics in poultry and livestock industry.

Enabling High-Voltage "Superconcentrated Ionogel-in-Ceramic" Hybrid Electrolyte with Ultrahigh Ionic Conductivity and Single Li+ -Ion Transference Number.

High room-temperature ionic conductivities, large Li+ -ion transference numbers, and good compatibility with both Li-metal anodes and high-voltage cathodes of the solid electrolytes are the essential requirements for practical solid-state lithium-metal batteries. Herein, a unique "superconcentrated ionogel-in-ceramic" (SIC) electrolyte prepared by an in situ thermally initiated radical polymerization is reported. Solid-state static 7 Li NMR and molecular dynamics simulation reveal the roles of ceramic in Li+ local environments and transport in the SIC electrolyte. The SIC electrolyte not only exhibits an ultrahigh ionic conductivity of 1.33 × 10-3 S cm-1 at 25 °C, but also a Li+ -ion transference number as high as 0.89, together with a low electronic conductivity of 3.14 × 10-10 S cm-1 and a wide electrochemical stability window of 5.5 V versus Li/Li+ . Applications of the SIC electrolyte in Li||LiNi0.5 Co0.2 Mn0.3 O2 and Li||LiFePO4 batteries further demonstrate the high rate and long cycle life. This study, therefore, provides a promising hybrid electrolyte for safe and high-energy lithium-metal batteries.

[Analysis of Heavy Metal Pollution Characteristics and Potential Ecological Risks of Surface Sediments in Dongjiang Lake].

To understand the pollution characteristics, spatial distribution characteristics, potential ecological risks, and sources of heavy metals in surface sediments of Dongjiang Lake, 12 surface sediment samples were collected from Dongjiang Lake. The contents of 20 heavy metals including Li, Be, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Ag, Cd, Cs, Ba, Pb, and U were analyzed in this study. The geo-accumulation index method and potential risk index method were used to evaluate the pollution degree and potential risks of heavy metals in sediments, and the correlation analysis and principal component analysis were used to trace the source of the primary heavy metals. The results showed that the average contents of ω(Cd)(2.25 mg·kg-1) and ω(As)(80.80 mg·kg-1) in heavy metals of Dongjiang Lake sediments were 21.2 times and 5.5 times the background value (0.11 mg·kg-1 and 14.7 mg·kg-1) of Hunan province. The overall spatial distribution of heavy metals was in the order of South>North>Central. The evaluation by the geo-accumulation index method showed that Cd was at the heavy pollution level, As and Se were at the moderate pollution level, Ag and Ga were at the light pollution level, and the other heavy metals were below the pollution standard. The evaluation by the potential risk index showed that all the surface sediments of Dongjiang Lake were at the high-risk level. The main environmental risk factor was Cd, which had an extremely high risk; the second was As, which had a medium risk; and the remaining heavy metals had no ecological risk.

Genome-wide association study and Mendelian randomization analysis provide insights for improving rice yield potential.

Rice yield per plant has a complex genetic architecture, which is mainly determined by its three component traits: the number of grains per panicle (GPP), kilo-grain weight (KGW), and tillers per plant (TP). Exploring ideotype breeding based on selection for genetically less complex component traits is an alternative route for further improving rice production. To understand the genetic basis of the relationship between rice yield and component traits, we investigated the four traits of two rice hybrid populations (575 + 1495 F1) in different environments and conducted meta-analyses of genome-wide association study (meta-GWAS). In total, 3589 significant loci for three components traits were detected, while only 3 loci for yield were detected. It indicated that rice yield is mainly controlled by minor-effect loci and hardly to be identified. Selecting quantitative trait locus/gene affected component traits to further enhance yield is recommended. Mendelian randomization design is adopted to investigate the genetic effects of loci on yield through component traits and estimate the genetic relationship between rice yield and its component traits by these loci. The loci for GPP or TP mainly had a positive genetic effect on yield, but the loci for KGW with different direction effects (positive effect or negative effect). Additionally, TP (Beta = 1.865) has a greater effect on yield than KGW (Beta = 1.016) and GPP (Beta = 0.086). Five significant loci for component traits that had an indirect effect on yield were identified. Pyramiding superior alleles of the five loci revealed improved yield. A combination of direct and indirect effects may better contribute to the yield potential of rice. Our findings provided a rationale for using component traits as indirect indices to enhanced rice yield, which will be helpful for further understanding the genetic basis of yield and provide valuable information for improving rice yield potential.