Reducing brassinosteroid signalling enhances grain yield in semi-dwarf wheat.

Modern green revolution varieties of wheat (Triticum aestivum L.) confer semi-dwarf and lodging-resistant plant architecture owing to the Reduced height-B1b (Rht-B1b) and Rht-D1b alleles1. However, both Rht-B1b and Rht-D1b are gain-of-function mutant alleles encoding gibberellin signalling repressors that stably repress plant growth and negatively affect nitrogen-use efficiency and grain filling2-5. Therefore, the green revolution varieties of wheat harbouring Rht-B1b or Rht-D1b usually produce smaller grain and require higher nitrogen fertilizer inputs to maintain their grain yields. Here we describe a strategy to design semi-dwarf wheat varieties without the need for Rht-B1b or Rht-D1b alleles. We discovered that absence of Rht-B1 and ZnF-B (encoding a RING-type E3 ligase) through a natural deletion of a haploblock of about 500 kilobases shaped semi-dwarf plants with more compact plant architecture and substantially improved grain yield (up to 15.2%) in field trials. Further genetic analysis confirmed that the deletion of ZnF-B induced the semi-dwarf trait in the absence of the Rht-B1b and Rht-D1b alleles through attenuating brassinosteroid (BR) perception. ZnF acts as a BR signalling activator to facilitate proteasomal destruction of the BR signalling repressor BRI1 kinase inhibitor 1 (TaBKI1), and loss of ZnF stabilizes TaBKI1 to block BR signalling transduction. Our findings not only identified a pivotal BR signalling modulator but also provided a creative strategy to design high-yield semi-dwarf wheat varieties by manipulating the BR signal pathway to sustain wheat production.

Thermosensitive SUMOylation of TaHsfA1 defines a dynamic ON/OFF molecular switch for the heat stress response in wheat.

Dissecting genetic components in crop plants associated with heat stress (HS) sensing and adaptation will facilitate the design of modern crop varieties with improved thermotolerance. However, the molecular mechanisms underlying the ON/OFF switch controlling HS responses (HSRs) in wheat (Triticum aestivum) remain largely unknown. In this study, we focused on the molecular action of TaHsfA1, a class A heat shock transcription factor, in sensing dynamically changing HS signals and regulating HSRs. We show that the TaHsfA1 protein is modified by small ubiquitin-related modifier (SUMO) and that this modification is essential for the full transcriptional activation activity of TaHsfA1 in triggering downstream gene expression. During sustained heat exposure, the SUMOylation of TaHsfA1 is suppressed, which partially reduces TaHsfA1 protein activity, thereby reducing the intensity of downstream HSRs. In addition, we demonstrate that TaHsfA1 interacts with the histone acetyltransferase TaHAG1 in a thermosensitive manner. Together, our findings emphasize the importance of TaHsfA1 in thermotolerance in wheat. In addition, they define a highly dynamic SUMOylation-dependent "ON/OFF" molecular switch that senses temperature signals and contributes to thermotolerance in crops.

Optical design and fabrication of a multi-channel imaging spectrometer for combustion flame monitoring.

We design and construct a broadband integrated multi-channel imaging spectrometer (MCIS) from visible light to near-infrared. This system can directly obtain spectral images that conform to the consistent visual habits of the human eyes through a single exposure of the detector. The genetic algorithm is used to calculate system parameters to minimize pixel waste between spectral channels, achieving nearly 100% utilization of detector pixels. The field stop suppresses stray light in the system. This device is used for imaging an optical-resolution target, an object, and a furnace to verify the basic principles of the system. The results indicate that the system can effectively utilize detectors to monitor high-temperature objects in the visible to near-infrared wavelength range.

DNA Molecular Glue Assisted Bacterial Conjugative Transfer.

Bacterial conjugation, a commonly used method to horizontally transfer functional genes from donor to recipient strains, plays an important role in the genetic manipulation of bacteria for basic research and industrial production. Successful conjugation depends on the donor-recipient cell recognition and a tight mating junction formation. However, the efficiency of conjugative transfer is usually very low. In this work, we developed a new technique that employed DNA molecule "glue" to increase the match frequency and the interaction stability between the donor and recipient cells. We used two E. coli strains, ETZ and BL21, as a model system, and modified them with the complementary ssDNA oligonucleotides by click chemistry. The conjugation efficiency of the modified bacteria was improved more than 4 times from 10% to 46%. This technique is simple and generalizable as it only relies on the active amino groups on the bacterial surface. It is expected to have broad applications in constructing engineered bacteria.

Preparation of 3D flexible SERS substrates by mixing gold nanorods in hydrogels for the detection of malachite green and crystal violet.

A simple and cost-effective fabrication method of gold nanorods (AuNRs) nanoparticles hybridized with polyvinyl alcohol hydrogel (AuNR/PVA) for SERS substrate is described. The AuNR/PVA achieves the control of inter-particle nanogap by modulating the density of gold nanorods, and inter-particle nanogap by the spatial deformation of the hydrogel, and the reduction of the gap between the AuNRs deposited on hydrogel makes the SERS enhancement. In addition, the AuNR/PVA substrate maintains high SERS activity after more than 100 cycles of bending and storage in air for 30 days, and the substrate possesses high sensitivity and high reproducibility. Combining a flexible and transparent surface-enhanced Raman spectroscopy (SERS) substrate for in situ detection with a small portable Raman can be applied to scenarios such as environmental detection and hazardous materials detection. The substrate showed excellent SERS activity against malachite green (MG) and crystal violet (CV) with limits of detection of 1.18 × 10-13 M and 7.17 × 10-12 M, respectively. The usability of the proposed SERS substrate was demonstrated by detecting the above contaminants in aquatic water. This work not only utilizes a cost-effective method for mass production but also provides a reliable and convenient platform for the preparation of other noble metal flexible substrates.

Hyperbranched Polymer Dots with Strong Absorption and High Fluorescence Quantum Yield for In Vivo NIR-II Imaging.

In order to improve the fluorescence quantum yield (QY) of NIR-II-emitting nanoparticles, D-A-D fluorophores are typically linked to intramolecular rotatable units to reduce aggregation-induced quenching. However, incorporating such units often leads to a twisted molecular backbone, which affects the coupling within the D-A-D unit and, as a result, lowers the absorption. Here, we overcome this limitation by cross-linking the NIR-II fluorophores to form a 2D polymer network, which simultaneously achieves a high QY by well-controlled fluorophore separation and strong absorption by restricting intramolecular distortion. Using the strategy, we developed polymer dots with the highest NIR-II single-particle brightness among reported D-A-D-based nanoparticles and applied them for imaging of hindlimb vasculatures and tumors as well as fluorescence-guided tumor resection. The high brightness of the polymer dots offered exceptional image quality and excellent surgical results, showing a promising performance for these applications.

Mitochondrial Protease Targeting Chimeras for Mitochondrial Matrix Protein Degradation.

Targeted protein degradation (TPD) is an emerging technique for protein regulation. Currently, all TPD developed in eukaryotic cells relies on either ubiquitin-proteasome or lysosomal systems, thus are powerless against target proteins in membrane organelles lacking proteasomes and lysosomes, such as mitochondria. Here, we developed a mitochondrial protease targeting chimera (MtPTAC) to address this issue. MtPTAC is a bifunctional small molecule that can bind to mitochondrial caseinolytic protease P (ClpP) at one end and target protein at the other. Mechanistically, MtPTAC activates the hydrolase activity of ClpP while simultaneously bringing target proteins into proximity with ClpP. Taking mitochondrial RNA polymerase (POLRMT) as a model protein, we have demonstrated the powerful proteolytic ability and antitumor application prospects of MtPTAC, both in vivo and in vitro. This is the first modularly designed TPD that can specifically hydrolyze target proteins inside mitochondria.

TaTPP-7A positively feedback regulates grain filling and wheat grain yield through T6P-SnRK1 signalling pathway and sugar-ABA interaction.

Grain size and filling are two key determinants of grain thousand-kernel weight (TKW) and crop yield, therefore they have undergone strong selection since cereal was domesticated. Genetic dissection of the two traits will improve yield potential in crops. A quantitative trait locus significantly associated with wheat grain TKW was detected on chromosome 7AS flanked by a simple sequence repeat marker of Wmc17 in Chinese wheat 262 mini-core collection by genome-wide association study. Combined with the bulked segregant RNA-sequencing (BSR-seq) analysis of an F2 genetic segregation population with extremely different TKW traits, a candidate trehalose-6-phosphate phosphatase gene located at 135.0 Mb (CS V1.0), designated as TaTPP-7A, was identified. This gene was specifically expressed in developing grains and strongly influenced grain filling and size. Overexpression (OE) of TaTPP-7A in wheat enhanced grain TKW and wheat yield greatly. Detailed analysis revealed that OE of TaTPP-7A significantly increased the expression levels of starch synthesis- and senescence-related genes involved in abscisic acid (ABA) and ethylene pathways. Moreover, most of the sucrose metabolism and starch regulation-related genes were potentially regulated by SnRK1. In addition, TaTPP-7A is a crucial domestication- and breeding-targeted gene and it feedback regulates sucrose lysis, flux, and utilization in the grain endosperm mainly through the T6P-SnRK1 pathway and sugar-ABA interaction. Thus, we confirmed the T6P signalling pathway as the central regulatory system for sucrose allocation and source-sink interactions in wheat grains and propose that the trehalose pathway components have great potential to increase yields in cereal crops.

ggComp enables dissection of germplasm resources and construction of a multiscale germplasm network in wheat.

Accurate germplasm characterization is a vital step for accelerating crop genetic improvement, which remains largely infeasible for crops such as bread wheat (Triticum aestivum L.), which has a complex genome that undergoes frequent introgression and contains many structural variations. Here, we propose a genomic strategy called ggComp, which integrates resequencing data with copy number variations and stratified single-nucleotide polymorphism densities to enable unsupervised identification of pairwise germplasm resource-based Identity-By-Descent (gIBD) blocks. The reliability of ggComp was verified in wheat cultivar Nongda5181 by dissecting parental-descent patterns represented by inherited genomic blocks. With gIBD blocks identified among 212 wheat accessions, we constructed a multi-scale genomic-based germplasm network. At the whole-genome level, the network helps to clarify pedigree relationship, demonstrate genetic flow, and identify key founder lines. At the chromosome level, we were able to trace the utilization of 1RS introgression in modern wheat breeding by hitchhiked segments. At the single block scale, the dissected germplasm-based haplotypes nicely matched with previously identified alleles of "Green Revolution" genes and can guide allele mining and dissect the trajectory of beneficial alleles in wheat breeding. Our work presents a model-based framework for precisely evaluating germplasm resources with genomic data. A database, WheatCompDB (http://wheat.cau.edu.cn/WheatCompDB/), is available for researchers to exploit the identified gIBDs with a multi-scale network.

Design of off-axis aspheric four-mirror non-axial mechanical zoom optical system with large relative aperture.

A large relative aperture is essential to improve the spatial resolution of zoom systems. To overcome the limitations of the existing off-axis reflective mechanical zoom system with a low zoom rate and a small relative aperture, this paper proposes a non-axis movement method for increasing the degrees of freedom. On the basis of nodal aberration theory, passive eccentricity is changed into active eccentricity to achieve wave aberration balance in the multiple structures of the zoom imaging system. An off-axis aspherical four-mirror non-axial mechanical zoom optical system is designed and fabricated. The prototype has been successfully processed and assembled with the help of computer-aided alignment technology. The prototype's F-number is 4 and zoom ratio is 4.57:1. Experimental results verify the feasibility of the proposed method.

Preparation of SERS base membrane with cellulose compound dopamine and determination of hypochlorite.

Flexible silver substrates were made by in situ reduction of silver nanoparticles in bacterial cellulose membranes using the unique advantage of dopamine. Subsequently, we modified the substrate with 4-mercaptophenol (4-MP), a molecule capable of specifically recognizing ClO-, and its corresponding SERS signal changes with the concentration of hypochlorite, thus allowing the quantitative detection of ClO- content. The method showed a negative linear correlation (R2 = 0.9567) with the SERS intensity at 1077 cm-1 over the concentration range 0.5-100 µM, and the detection limit was 0.15 µM. The RSD of the SERS intensity at 1077 cm-1 under five batches was 4.2%, which proved the good reproducibility of P-BCM-Ag NP-MP. Finally, the P-BCM-Ag NPs were used for the detection of hypochlorite in cell contents, artificial urine, and clinical serum samples, utilizing spike experiments in all three environments. The recoveries were in the range 90-110% indicating the accuracy of the method for the detection of hypochlorite and validating the promising application of this assay for practical detection in intricate biological samples.

A novel "on-off" SERS nanoprobe based on sulfonated cellulose nanofiber-Ag composite for selective determination of NADH in human serum.

A novel S-CNF-based nanocomposite was created using sulfonated cellulose nanofiber (S-CNF) to enable the detection of NADH in serum by surface-enhanced Raman spectroscopy (SERS). The numerous hydroxyl and sulfonic acid groups on the S-CNF surface absorbed silver ions and converted them to silver seeds, which formed the load fulcrum. After adding a reducing agent, silver nanoparticles (Ag NPs) were firmly adhered to the S-CNF surface to form stable 1D "hot spots." The S-CNF-Ag NP substrate demonstrated outstanding SERS performance, including good uniformity with an RSD of 6.88% and an enhancement factor (EF) of 1.23 × 107. Owing to the anionic charge repulsion effect, the S-CNF-Ag NP substrate still maintains remarkable dispersion stability after 12 months of preservation. Finally, S-CNF-Ag NPs' surface was modified with 4-mercaptophenol (4-MP), a special redox Raman signal molecule, to detect reduced nicotinamide adenine dinucleotide (NADH). The results showed that the detection limit (LOD) of NADH was 0.75 µM; a good linear relationship (R2 = 0.993) was established in the concentration range 10-6 - 10-2 M. The SERS nanoprobe enabled rapid detection of NADH in human serum without any complicated sample pretreatment and provides a new potential to detect biomarkers.

A butenolide signaling system synergized with biosynthetic gene modules led to effective activation and enhancement of silent oviedomycin production in Streptomyces.

Secondary metabolic gene clusters widely exist in the genomes of Streptomyces but mostly remain silent. To awaken this hidden reservoir of natural products, various strategies concerning secondary metabolic pathways are applied. Here, we describe that butenolide signaling molecule deficiency and glucose addition can interdependently activate the expression of silent oviedomycin biosynthetic gene clusters in Streptomyces ansochromogenes and Streptomyces antibioticus. Since oviedomycin is a promising anti-tumor lead compound, in order to improve its yield, we use the cluster-situated genes (ovmF, ovmG, ovmI and ovmH) encoding the enzymes for acyl carrier protein modification and precursor biosynthesis, and the discrete precursor biosynthetic genes (pyk2, gap1 and accA2) involved in glycolysis to assemble two gene modules (pFGIH and pPGA). Their co-overexpression in ΔsabA (a disruption mutant of sabA encoding SAB synthase) has superimposed effect on the yield of oviedomycin, which can be further increased to 59-fold in the presence of galactose as optimal carbon source. This is the most unambiguous evidence that butenolide signaling system can synergize with the optimization of primary metabolism to regulate the expression of secondary metabolic gene clusters, providing efficient strategies for mining natural products of Streptomyces.

Roles of PTEN inactivation and PD-1/PD-L1 activation in esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is the most common type of esophageal cancer in China and developing countries. The purpose of this review is to summarize the roles of inactivation of the tumor suppressor gene, phosphatase and tensin homolog (PTEN), and activation of the programmed cell death protein 1 (PD-1) upon binding to its ligand (PD-L1) in the promotion of ESCC. Studies of ESCC performed in vitro and in vivo indicated that PTEN and PD-L1 function in the regulation of cell proliferation, invasion, and migration; the epithelial-mesenchymal transition; resistance to chemotherapy and radiotherapy; and the PI3K/AKT signaling pathway. Certain genetic variants of PTEN are related to susceptibility to ESCC, and PTEN and PD-L1 also function in ESCC progression and affect the prognosis of patients with ESCC. There is also evidence that the expression of PD-L1 and PTEN are associated with the progression of certain other cancers. Future studies should further examine the relationship of PD-L1 and PTEN and their possible interactions in ESCC.

An Improved Entropy-Weighted Topsis Method for Decision-Level Fusion Evaluation System of Multi-Source Data.

Due to the rapid development of industrial internet technology, the traditional manufacturing industry is in urgent need of digital transformation, and one of the key technologies to achieve this is multi-source data fusion. For this problem, this paper proposes an improved entropy-weighted topsis method for a multi-source data fusion evaluation system. It adds a fusion evaluation system based on the decision-level fusion algorithm and proposes a dynamic fusion strategy. The fusion evaluation system effectively solves the problem of data scale inconsistency among multi-source data, which leads to difficulties in fusing models and low fusion accuracy, and obtains optimal fusion results. The paper then verifies the effectiveness of the fusion evaluation system through experiments on the multilayer feature fusion of single-source data and the decision-level fusion of multi-source data, respectively. The results of this paper can be used in intelligent production and assembly plants in the discrete industry and provide the corresponding management and decision support with a certain practical value.

Extracellular vesicles isolated by size-exclusion chromatography present suitability for RNomics analysis in plasma.

BACKGROUND: Extracellular vesicles (EVs), known as cell-derived membranous structures harboring a variety of biomolecules, have been widely used in liquid biopsy. Due to the complex biological composition of plasma, plasma RNA omics analysis (RNomics) is easily affected, thus it is necessary to select an optimal strategy from exiting methods according to the performance for intended application. METHODS: In this study, four different strategies for EVs isolation were performed and compared (i.e. ultracentrifugation (UC), size exclusion chromatography (SEC), and two most frequently-used commercially available isolation kit (ExoQuick and exoEasy). We compared the yield, purity, PCR quantification of RNAs, miRNA-seq analyses and mRNA-seq analyses of RNAs from EVs isolated using four methods. RESULTS: The results showed that the lowest miRNA binding protein AGO2 (Argonaute-2) and the highest EVs-specific miRNA and lncRNA were observed in EVs obtained through SEC, meanwhile the content of the non-specific miRNA was the lowest. Further RNA-Seq data revealed that RNAs obtained via SEC presented more useful reads for both miRNA and mRNA. Furthermore, the mRNA delivered via SEC tended to have a concentration comparable to the ideal FPKM (Fragments Per Kilobase Million) value. CONCLUSIONS: SEC shall be used as an optimal strategy for the isolation of EVs in plasma RNomics analysis.

Preparation and Biological Property Evaluation of Novel Cationic Lipid-Based Liposomes for Efficient Gene Delivery.

Novel cationic lipid-based liposomes prepared using an amphiphilic cationic lipid material, N,N-dimethyl-(N',N'-di-stearoyl-1-ethyl)1,3-diaminopropane (DMSP), have been proposed to enhance the transfection of nucleic acids. Herein, we designed and investigated liposomes prepared using DMSP, soybean phosphatidylcholine, and cholesterol. This novel gene vector has high gene loading capabilities and excellent protection against nuclease degradation. An in vitro study showed that the liposomes had lower toxicity and superior cellular uptake and transfection efficiency compared with Lipofectamine 2000. An endosomal escape study revealed that the liposomes demonstrated high endosomal escape and released their genetic payload in the cytoplasm efficiently. Mechanistic studies indicated that the liposome/nucleic acid complexes entered cells through energy-dependent endocytosis that was mediated by fossa proteins. These results suggest that such cationic lipid-based liposome vectors have potential for clinical gene delivery.

The Opposed Effects of Polyvinylpyrrolidone K30 on Dissolution and Precipitation for Indomethacin Supersaturating Drug Delivery Systems.

Amorphous solid dispersions (ASD) are one of the most important supersaturating drug delivery systems (SDDS) for poorly water-soluble drugs to improve their bioavailability. As a result of thermodynamic instability, drug molecules tend to precipitate during storage and dissolution in gastrointestinal tract. Various precipitation inhibitors (PI) have been widely used to improve the stability in the past decade. However, most studies have investigated the inhibiting capability of PI on drug precipitation, rarely considering their potential hindering effect on the drug dissolution. The present study designed an ASD of Indomethacin (IND) and Eudragit® EPO by hot melt extrusion to investigate the influence of the added PI (PVP-K30) into ASD both on dissolution and precipitation. The precipitation study by solvent shift method indicated PVP-K30 could inhibit the precipitation of IND significantly. The dissolution study in different concentrations of PVP-K30 showed when the concentration increased above 50 µg/mL, PVP-K30 displayed an acceptable precipitation inhibition without drug concentration decline but an unexpected dissolution impediment with the reduction of maximum concentration platform. The dissolution tests of physical mixtures (PMs) of ASD and PVP-K30 also showed the precipitation inhibition and dissolution impediment when more than 2% PVP-K30 in PMs. This opposed effect of PVP-K30 was strengthen in ternary systems prepared by hot melt extruding the mixtures of IND, Eudragit® EPO and PVP-K30. All of these results proved the PI may be a double-edged sword for the opposed effects of precipitation inhibition and dissolution impediment, which should be carefully considered in the design and development of SDDS.

A Site-Selective Doping Strategy of Carbon Anodes with Remarkable K-Ion Storage Capacity.

The limited potassium-ion intercalation capacity of graphite hampers development of potassium-ion batteries (PIB). Edge-nitrogen doping is an effective approach to enhance K-ion storage in carbonaceous materials. One shortcoming is the lack of precise control over producing the edge-nitrogen configuration. Here, a molecular-scale copolymer pyrolysis strategy is used to precisely control edge-nitrogen doping in carbonaceous materials. This process results in defect-rich, edge-nitrogen doped carbons (ENDC) with a high nitrogen-doping level (up to 10.5 at %) and a high edge-nitrogen ratio (87.6 %). The optimized ENDC exhibits a high reversible capacity of 423 mAh g-1 , a high initial Coulombic efficiency of 65 %, superior rate capability, and long cycle life (93.8 % retention after three months). This strategy can be extended to design other edge-heteroatom-rich carbons through pyrolysis of copolymers for efficient storage of various mobile ions.

Identification of a butenolide signaling system that regulates nikkomycin biosynthesis in Streptomyces.

Butenolides are an emerging family of signaling molecules in Streptomyces. They control complex physiological traits, such as morphological differentiation and antibiotic production. However, how butenolides regulate these processes is poorly investigated because of obstacles in obtaining these signaling molecules. This study reports the identification of a butenolide-type signaling system for nikkomycin biosynthesis in Streptomyces ansochromogenes with distinct features. We identified a gene cluster, sab, consisting of three genes, sabAPD, for butenolide biosynthesis and two regulator genes, sabR1 and sabR2, and characterized three butenolides (SAB1, -2, and -3) by heterologous expression of sabAPD. sabA disruption abolished nikkomycin production, which could be restored by the addition of SABs or by deletion of sabR1 in ΔsabA. Electrophoretic mobility-shift assays and transcriptional analyses indicated that SabR1 indirectly represses the transcription of nikkomycin biosynthetic genes, but directly represses sabA and sabR1 In the presence of SABs, the SabR1 transcriptional regulator dissociated from its target genes, verifying that SabR1 is the cognate receptor of SABs. Genome-wide scanning with the conserved SabR1-binding sequence revealed another SabR1 target gene, cprC, whose transcription was strongly repressed by SabR1. Intriguingly, CprC positively regulated the pleiotropic regulatory gene adpA by binding to its promoter and, in turn, activated nikkomycin biosynthesis. This is the first report that butenolide-type signaling molecules and their cognate receptor SabR1 can regulate adpA via a newly identified activator, CprC, to control nikkomycin production. These findings pave the way for further studies seeking to unravel the regulatory mechanism and functions of the butenolide signaling system in Streptomyces.