Fluorinated carbon as high-performance cathode for aqueous zinc primary batteries.

Fluorinated carbon (CFx) has been extensively served as promising positive electrode material for lithium primary batteries due to its high energy density. However, there are comparatively far less reports about the use of CFx on other battery systems, let alone on the research of aqueous batteries. Herein in this study, we employed CFx as the cathode active for aqueous zinc batteries for the first time and systematically investigated its electrochemical behavior under a series of aqueous zinc-ion electrolytes. As is discovered that the F/C ratio (the x value in CFx) of CFx have significant effects on the electrochemical performance of aqueous Zn/CFx batteries. Specifically, CF0.85 exhibits excellent electrochemical property with delivering a remarkable discharge capacity of 503 mA h g-1 and energy density of 388 W h kg-1 (at a current rate of 30 mA g-1 under temperature of 25 °C), much better than several other CFx electrode with F/C ratio of 0.70, 0.95, and 1.10, respectively. Besides, it also exhibits decent temperature performance with discharge capacities of 550 mA h g-1 at 50 °C and 460 mA h g-1 at 0 °C under current density of 30 mA g-1. Furthermore, the electrochemical discharge mechanism based on conversion reaction was further uncovered by applying XPS, XRD, SEM and EDS elemental analysis characterization techniques. In conclusion, these results demonstrate the potential application value of CFx in aqueous zinc primary batteries.

Integrated Transcriptomics and Metabolomics Analyses Provide Insights into Qingke in Response to Cold Stress.

The survival and productivity of qingke in high altitude (>4300 m, average yearly temperature <0 °C) of the Tibetan Plateau are significantly impacted by low-temperature stress. Uncovering the mechanisms underlying low-temperature stress response in cold-tolerant qingke varieties is crucial for qingke breeding. Herein, we conducted a comprehensive transcriptomic and metabolomic analysis on cold-sensitive (ZQ) and cold-tolerant (XL) qingke varieties under chilling and freezing treatments and identified lipid metabolism pathways as enriched in response to freezing treatment. Additionally, a significant positive correlation was observed between the expression of C-repeat (CRT) binding factor 10A (HvCBF10A) and Gly-Asp-Ser-Leu-motif lipase (HvGDSL) and the accumulation of multiple lipids. Functional analysis confirmed that HvCBF10A directly binds to HvGDSL, and silencing HvCBF10A resulted in a significant decrease in both HvGDSL and lipid levels, consequently impairing the cold tolerance. Overall, HvCBF10A and HvGDSL are functional units in actively regulating lipid metabolism to enhance freezing stress tolerance in qingke.

Nutrient Metabolism Pathways Analysis and Key Candidate Genes Identification Corresponding to Cadmium Stress in Buckwheat through Multiomics Analysis.

Fagopylum tatarium (L.) Gaertn (buckwheat) can be used both as medicine and food and is also an important food crop in barren areas and has great economic value. Exploring the molecular mechanisms of the response to cadmium (Cd) stress can provide the theoretical reference for improving the buckwheat yield and quality. In this study, perennial tartary buckwheat DK19 was used as the experimental material, its key metabolic pathways in the response to Cd stress were identified and verified through transcriptomic and metabolomic data analysis. In this investigation, 1798 metabolites were identified through non-targeted metabolomic analysis containing 1091 up-regulated and 984down-regulated metabolites after treatment. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of differential metabolites was significantly enriched in galactose metabolism, glycerol metabolism, phenylpropane biosynthesis, glutathione metabolism, starch and sucrose metabolism. Linkage analysis detected 11 differentially expressed genes (DEGs) in the galactose metabolism pathway, 8 candidate DEGs in the lipid metabolism pathway, and 20 candidate DEGs in the glutathione metabolism pathway. The results of our study provided useful clues for genetically improving the resistance to cadmium by analyzing the molecular mechanism of cadmium tolerance in buckwheat.

Watermelon domestication was shaped by stepwise selection and regulation of the metabolome.

Although crop domestication has greatly aided human civilization, the sequential domestication and regulation of most quality traits remain poorly understood. Here, we report the stepwise selection and regulation of major fruit quality traits that occurred during watermelon evolution. The levels of fruit cucurbitacins and flavonoids were negatively selected during speciation, whereas sugar and carotenoid contents were positively selected during domestication. Interestingly, fruit malic acid and citric acid showed the opposite selection trends during the improvement. We identified a novel gene cluster (CGC1, cucurbitacin gene cluster on chromosome 1) containing both regulatory and structural genes involved in cucurbitacin biosynthesis, which revealed a cascade of transcriptional regulation operating mechanisms. In the CGC1, an allele caused a single nucleotide change in ClERF1 binding sites (GCC-box) in the promoter of ClBh1, which resulted in reduced expression of ClBh1 and inhibition of cucurbitacin synthesis in cultivated watermelon. Functional analysis revealed that a rare insertion of 244 amino acids, which arose in C. amarus and became fixed in sweet watermelon, in ClOSC (oxidosqualene cyclase) was critical for the negative selection of cucurbitacins during watermelon evolution. This research provides an important resource for metabolomics-assisted breeding in watermelon and for exploring metabolic pathway regulation mechanisms.

Disease resistance conferred by components of essential chrysanthemum oil and the epigenetic regulation of OsTPS1.

The sesquiterpene alpha-bisabolol is the predominant active ingredient in essential oils that are highly valued in the cosmetics industry due to its wound healing, anti-inflammatory, and skin-soothing properties. Alpha-bisabolol was thought to be restricted to Compositae plants. Here we reveal that alpha-bisabolol is also synthesized in rice, a non-Compositae plant, where it acts as a novel sesquiterpene phytoalexin. Overexpressing the gene responsible for the biosynthesis of alpha-bisabolol, OsTPS1, conferred bacterial blight resistance in rice. Phylogenomic analyses revealed that alpha-bisabolol-synthesizing enzymes in rice and Compositae evolved independently. Further experiments demonstrated that the natural variation in the disease resistance level was associated with differential transcription of OsTPS1 due to polymorphisms in its promoter. We demonstrated that OsTPS1 was regulated at the epigenetic level by JMJ705 through the methyl jasmonate pathway. These data reveal the cross-family accumulation and regulatory mechanisms of alpha-bisabolol production.

Integrative metabolomic and transcriptomic analyses reveal the mechanisms of Tibetan hulless barley grain coloration.

Cereal grains accumulate anthocyanin during developmental process. The anthocyanin content increases at grain filling stages to develop grain coloration in cereals. However, anthocyanin biosynthesis responsible for grain coloring and its regulatory mechanisms controlled by structural and functional genes remain unclear. Therefore, this study aimed to explore the global map of metabolic changes linked to grain coloration of Tibetan hulless barley (qingke) using an integrative metabolome and transcriptome approach. Grains from three colored qingke cultivars at different developmental stages were considered for molecular and metabolic investigations. A total of 120 differentially accumulated metabolites (DAMs) and 8,327 differentially expressed genes (DEGs) were filtered. DEGs were mainly enriched in the phenylpropanoid and flavonoid pathways. The transcript levels of anthocyanin biosynthesis genes (PAL, C4H, 4CL, CHS, FLS, F3H, F3'H, DFR, ANS, GT, OMT, and MAT) significantly upregulate in colored qingke compared to the non-colored variety. During grain development and maturation, the strong correlation of HvMYC2 expression with anthocyanin contents and anthocyanin biosynthesis genes suggested it as a critical gene in anthocyanin accumulation. Further results confirmed that HvMYC2 could be activated by HvMYB and be a positive regulator of UV-B and cold tolerance in qingke. In addition, verification based on enzymatic assays indicated that six key modifier enzymes could catalyze glycosylation, malonylation, and methylation of anthocyanins, thereby dissecting the major anthocyanin modification pathway in colored qingke. Overall, our study provides global insight into anthocyanin accumulation and the mechanism underlying grain coloration in qingke.

Resistance to Powdery Mildew in Qingke Involves the Accumulation of Aromatic Phenolamides Through Jasmonate-Mediated Activation of Defense-Related Genes.

Powdery mildew (PM) leads to severe yield reduction in qingke (Hordeum vulgare L. var. nudum). Although studies have focused on identifying PM-related resistance genes, mechanistic insights into the metabolic regulation networks of resistance against PM have rarely been explored in qingke. Here, we integrated transcriptomic, proteomic and metabolomic data using PM-susceptible (G72) and PM-resistant (K69) accessions to systemically explore the mechanisms of PM resistance. The integrated results show that a rapidly transduction of jasmonic acid (JA) and (+)-7-iso-jasmonoyl-L-isoleucine (JA-Ile), and importantly, a inducing accumulation of aromatic PAs conferred qingke-specific resistance for PM stress. Functional analysis revealed that the four BAHD N-acyltransferase genes were responsible for the synthesis of aliphatic and aromatic PAs. The expression of the four genes are induced by methyl jasmonate (MeJA) and PM treatment. Co-expression network analysis shows that a histone lysine demethylase, JMJ705 gene, also induced by MeJA and PM treatment, had highly correlation with PAs biosynthesis. Chromatin immunoprecipitation (ChIP)-seq assays revealed that the level of trimethylated histone H3 lysine 27 (H3K27me3) of the four genes in MeJA and PM-treated plants was significantly reduced. Overall, our results suggest that a novel strategy for jasmonic acid signal-mediated demethylation controlling the accumulation of aromatic PAs to enhance plant immune resistance through removal of H3K27me3 and activating defense-related gene expression.

Structure and Performance of NaxMn0.85Al0.1Fe0.05O2 (0.7 ≤ x ≤ 1.0) Composite Materials for Sodium-Ion Batteries.

P2 and O3 structures are two important sodium manganese oxide phases for sodium-ion batteries; however, encounter Na-deficient and poor rate performance, respectively. Herein, a systematic study of NaxMn0.85Al0.1Fe0.05O2 (0.7 ≤ x ≤ 1.0) materials is performed by employing solid-state NMR, X-ray diffraction, and electrochemical analysis, to provide an in-depth understanding on the structure and the correlated performance for the rational design. The interlayer spacing of α-NaMnO2 broadens, and the content of distorted O3 structures (α- and ß-NaMnO2) increases with raising Na content. It is exhibited that the NaMn0.85Al0.1Fe0.05O2 composite material presents better rate and cycling performance than P2-type Na0.7Mn0.85Al0.1Fe0.05O2, delivering a capacity of 87 mAh g-1 at 5 C. Significantly, the determinants of performance are further discussed, which reveal that diffusion coefficient is probably not the decisive factor restricts the rate performance of O3 and composite materials. The phase transition relaxation and the interfacial charge transfer resistance should be seriously addressed for further improvement.

Metabolome-Based Genome-Wide Association Study Provides Genetic Insights Into the Natural Variation of Foxtail Millet.

The plant metabolome is considered as a bridge between the genome and the phenome and is essential for the interaction between plant growth and the plant environment. Here, we used the liquid chromatography-tandem mass spectrometry method to perform a widely targeted metabolomics analysis of 150 millet germplasm and simultaneous identification and quantification of 330 annotated metabolites. Comparing the metabolic content of different millets revealed significant natural variation of both primary and secondary metabolites, including flavonoids, phenolamides, hydroxycinnamoyl derivatives, nucleotides, and lipids, in the millets from India and the north and south of China; among them, some of the flavonoids are the most prominent. A total of 2.2 TB sequence data were obtained by sequencing 150 accessions of foxtail millet using the Illumina platform. Further digging into the genetic basis of metabolites by mGWAS analysis found that cyanidin 3-O-glucoside and quercetin O-acetylhexside are concentratedly located at 43.55 Mb on chromosome 5 and 26.9 Mb on chromosome 7, and two Lc were mined as candidate genes, respectively. However, the signals of luteolin 7-O-glucoside and kaempferol 3-O-glucoside were also detected at 14.36 Mb on chromosome 3, and five glycosyltransferase genes on this loci were deemed to regulate their content. Our work is the first research to use mGWAS in millet, and it paves the way for future dissection of complex physiological traits in millet.

Drought Resistance in Qingke Involves a Reprogramming of the Phenylpropanoid Pathway and UDP-Glucosyltransferase Regulation of Abiotic Stress Tolerance Targeting Flavonoid Biosynthesis.

Tibetan hulless barley (qingke) is an important food crop in the Tibetan plateau. However, it often suffers from drought stress resulting in reduction of food production because of the extreme plateau environment. To elucidate the molecular mechanisms underlying the drought resistance of qingke, the transcriptomic and metabolomic responses of drought-sensitive (D) and drought-resistant (XL) accessions were characterized in experiments with a time course design. The phenylpropanoid pathway was reprogrammed by downregulating the lignin pathway and increasing the biosynthesis of flavonoids and anthocyanins, and this regulation improved plant tolerance for drought stress. Besides, flavonoid glycosides have induced accumulation of metabolites that participated in drought stress resistance. HVUL7H11410 exhibited the activity of wide-spectrum glucosyltransferase and mediated flavonoid glycosylation to enhance drought stress resistance. Overall, the findings provide insights into the regulatory mechanism underlying drought stress tolerance associated with metabolic reprogramming. Furthermore, the flavonoid-enriched qingke is more tolerant to drought stress and can be used as a functional food to benefit human health.

An Oryza-specific hydroxycinnamoyl tyramine gene cluster contributes to enhanced disease resistance.

Genomic clustering of non-homologous genes for the biosynthesis of plant defensive compounds is an emerging theme, but insights into their formation and physiological function remain limited. Here we report the identification of a newly discovered hydroxycinnamoyl tyramine (HT) gene cluster in rice. This cluster contains a pyridoxamine 5'-phosphate oxidase (OsPDX3) producing the cofactor pyridoxal 5'-phosphate (PLP), a PLP-dependent tyrosine decarboxylase (OsTyDC1), and two duplicated hydroxycinnamoyl transferases (OsTHT1 and OsTHT2). These members were combined to represent an enzymological innovation gene cluster. Natural variation analysis showed that the abundance of the toxic tyramine intermediate of the gene cluster among different rice accessions is mainly determined by the coordinated transcription of OsTyDC1 and OsTHT1. Further pathogen incubation assays demonstrated that the end products of the HT gene cluster displayed enhanced resistance to the bacterial pathogen Xanthomonas oryzae pv. Oryzae (Xoo) and fungal pathogen Magnaporthe oryzae (M. oryzae), and the enhanced resistance is associated with the boost of phytoalexins and the activation of defense response. The unique presence of the HT gene cluster in Oryza AA genome, together with the enrichment of transposon elements within this gene cluster region, provides an evolutionary background to accelerate cluster member combinations. Our study not only discovered a gene cluster involved in the phenylpropanoid metabolism but also addressed the key aspects of gene cluster formation. In addition, our results provide a new metabolic pool for plant defense against pathogens.

Molecular Mechanism of Slow Vegetative Growth in Populus Tetraploid.

Tetraploid plants often have altered rates of vegetative growth relative to their diploid progenitors. However, the molecular basis for altered growth rates remains a mystery. This study reports microRNA (miRNA) and gene expression differences in Populus tetraploids and counterpart diploids using RNA and miRNA sequencing. The results showed that there was no significant difference between young leaves in the expression of vegetative growth-related miRNAs. However, as leaves aged, the expression of auxin- and gibberellin-related miRNAs was significantly upregulated, while the expression of senescence-related miRNAs was significantly downregulated. The dose effect enhanced the negative regulation of the target genes with ARFs, GA20ox, GA3ox, and GAMYB being downregulated, and TCP and NAC being upregulated. As a result, the chloroplast degradation of tetraploid leaves was accelerated, the photosynthetic rate was decreased, and the synthesis and decomposition ability of carbohydrate was decreased.

[Independent prognostic factors and survival prediction model for 117 patients with advanced oral squamous cell carcinoma].

PURPOSE: To investigate the independent prognostic factors and establish survival prediction model for advanced oral squamous cell carcinoma (OSCC). METHODS: At the time of admission, the general information and past medical history of 177 patients with advanced OSCC were collected in detail. All patients underwent radical resection. After surgery, radiotherapy and chemotherapy with hydroxycampothecin (HCPT) and pingyangmycin (PYM) were performed according to the patient's condition. All patients were followed up for 5 years after surgery, and the survival rate during that period and the risk factors for prognosis were analyzed. The data were analyzed by SPSS 20.0 software package. RESULTS: During the follow-up period, 2 patients died due to other causes, 4 were excluded due to lost to follow-up, 42 of the remaining 111 patients died, 69 survived, the total survival rate was 62.16%. The survival status of patients with advanced OSCC with different age, T stage and M stage had no significant difference (P>0.05), while significant difference was found among patients with different gender, tissue differentiation degree, N stage and chemotherapy (P<0.05). Gender, N stage and HCPT in combination of PYM chemotherapy were independent risk factors (P<0.05), while histological differentiation degree was not an independent risk factor for survival of patients (P>0.05). The survival curves of gender, N stage and HCPT in combination of PYM chemotherapy had certain predictive value on the survival of patients with advanced OSCC. CONCLUSIONS: Gender, N stage and HCPT in combination of PYM chemotherapy are independent risk factors for the survival of patients with advanced OSCC, and their survival curves can be used as a survival prediction model.

Analysis of genetic composition and transmitted parental heterozygosity of natural 2n gametes in Populus tomentosa based on SSR markers.

MAIN CONCLUSION: Natural 2n female gametes and transmission of parental heterozygosity by natural 2n gametes in Populus tomentosa are reported for the first time, which provides a new approach to polyploid breeding. Naturally occurring 2n pollen is widespread in Populus tomentosa and plays an important role in polyploid breeding. However, the competitiveness of 2n pollen is lower than that of haploid pollen during pollination and fertilization, so 2n pollen is less efficient at fertilizing haploid female gametes to produce polyploids. In theory, polyploids can also be obtained when 2n female gametes are fertilized by haploid pollen. Thus, the question becomes whether natural 2n female gametes exist in P. tomentosa, which can be answered by examining the genetic composition of natural 2n gametes. In this study, the origin of 87 triploids from the hybrid combination "X-2 × Z-5" was identified by SSR markers and 21% of natural 2n gametes were found to originate from female parents. Four SSR loci with low recombination rates were used to identify the genetic composition of natural 2n gametes. The results showed that the genetic composition of 2n female gametes was mainly characterized by SDR, while 2n male gametes were mainly produced by FDR. Moreover, the transmission of parental heterozygosity by natural 2n gametes, which is significantly different between female and male parents in FDR and SDR types, was analysed using 42 SSR primers. Here, we report naturally occurring 2n female gametes for the first time in P. tomentosa and reveal the genetic constitution and transmitted parental heterozygosity of these gametes. Our results provide a foundation for theoretical research into 2n gametes and their application in new polyploid breeding strategies.