Cell size and xylem differentiation regulating genes from Salicornia europaea contribute to plant salt tolerance

Cell wall is involved in plant growth and plays pivotal roles in plant adaptation to environmental stresses. Cell wall remodelling may be crucial to salt adaptation in the euhalophyte Salicornia europaea. However, the mechanism underlying this process is still unclear. Here, full-length transcriptome indicated cell wall-related genes were comprehensively regulated under salinity. The morphology and cell wall components in S. europaea shoot were largely modified under salinity. Through the weighted gene co-expression network analysis, SeXTH2 encoding xyloglucan endotransglucosylase/hydrolases, and two SeLACs encoding laccases were focused. Meanwhile, SeEXPB was focused according to expansin activity and the expression profiling. Function analysis in Arabidopsis validated the functions of these genes in enhancing salt tolerance. SeXTH2 and SeEXPB overexpression led to larger cells and leaves with hemicellulose and pectin content alteration. SeLAC1 and SeLAC2 overexpression led to more xylem vessels, increased secondary cell wall thickness and lignin content. Notably, SeXTH2 transgenic rice exhibited enhanced salt tolerance and higher grain yield. Altogether, these genes may function in the succulence and lignification process in S. europaea. This work throws light on the regulatory mechanism of cell wall remodelling in S. europaea under salinity and provides potential strategies for improving crop salt tolerance and yields.

PHT1;5 Repressed by ANT Mediates Pi Acquisition and Distribution under Low Pi and Salinity in Salt Cress

Salinity and phosphate (Pi) starvation are the most common abiotic stresses that threaten crop productivity. Salt cress (Eutrema salsugineum) displays good tolerance to both salinity and Pi limitation. Previously, we found several Phosphate Transporter (PHT) genes in salt cress upregulated under salinity. Here, EsPHT1;5 induced by both low Pi (LP) and salinity was further characterized. Overexpression of EsPHT1;5 in salt cress enhanced plant tolerance to LP and salinity, while the knock-down lines exhibited growth retardation. The analysis of phosphorus (P) content and shoot/root ratio of total P in EsPHT1;5-overexpressing salt cress seedlings and the knock-down lines as well as arsenate uptake assays suggested the role of EsPHT1;5 in Pi acquisition and root-shoot translocation under Pi limitation. In addition, overexpression of EsPHT1;5 driven by the native promoter in salt cress enhanced Pi mobilization from rosettes to siliques upon a long-term salt treatment. Particularly, the promoter of EsPHT1;5 outperformed that of AtPHT1;5 in driving gene expression under salinity. We further identified a transcription factor EsANT, which negatively regulated EsPHT1;5 expression and plant tolerance to LP and salinity. Taken together, EsPHT1;5 plays an integral role in Pi acquisition and distribution in plant response to LP and salt stress. Further, EsANT may be involved in the cross-talk between Pi starvation and salinity signaling pathways. This work provides further insight into the mechanism underlying high P use efficiency in salt cress in its natural habitat, and evidence for a link between Pi and salt signaling.

Nondestructive discrimination of Potentilla anserina L. from different production areas based on near-infrared spectroscopy

INTRODUCTION

The traditional Chinese medicine (TCM) Potentilla anserina L. can use both as food and medicine. At present, the market mainly depends on experience to identify the species and determine the production areas of P. anserina. To ensure the quality of P. anserina, it is essential to improve the level of quality control.

OBJECTIVE

We aimed to establish a rapid and nondestructive discrimination model to identify P. anserina from different production areas by near-infrared spectroscopy.

METHODS

The spectra of complete P. anserina medicinal materials and their powder of the same variety from four production areas were collected, and principal component analysis discriminant analysis and partial least squares discriminant analysis (PLS-DA) were conducted based on different pretreatment methods and band selection methods. Then, the spectra of complete medicinal materials were converted into the spectra of medicinal powder for nondestructive identification.

RESULTS

The correct recognition rate (CRR) of the PLS-DA discriminant model was the best after spectral preprocessing using autoscaling and competitive adaptive reweighted sampling for band selection. The CRRs of the calibration set and validation set were 100%, the CRRs of the external test set were 95%, 90%, 82%, and 88%, respectively, and the CRRs of the transfer external test set were 84%, 80%, 82%, and 86%, respectively.

CONCLUSION

We realized the nondestructive and effective identification of P. anserina from different origins and laid a foundation for the industrialization and upgrading of TCM.

Water Extract of Portulaca Oleracea Inhibits PEDV Infection-Induced Pyrolysis by Caspase-1/GSDMD

Porcine epidemic diarrhea virus (PEDV) belongs to the coronavirus family and the coronavirus genus, causing contact enteric infection in pigs. It is one of the most serious diseases that threatens the pig industry. However, there is currently no specific drug to prevent and treat the disease, indicating that we need to be vigilant about the spread of the disease and the development of anti-PEDV drugs. The dried aerial parts of the plant Portulaca oleracea in the family Portulacaceous, whose decoction can be used to treat acute enteritis, dysentery, diarrhea, and other diseases. This study explored the potential mechanism of water extract of Portulaca oleracea (WEPO) in PEDV-induced pyroptosis in Vero cells. PEDV decreased the viability of Vero cells in a dose- and time-dependent manner, causing cell damage, upregulating the level of intracellular Nlrp3, and inhibiting the level of Gasdermin D (GSDMD) and the activation of Caspase-1. WEPO can inhibit PEDV-induced pyroptosis, reduce the elevation of inflammatory factors caused by infection, and exhibit a dose-dependent effect. Knockdown of Caspase-1 and GSDMD separately can induce the production of the inflammatory factor IL-1β to significantly decrease and increase, respectively. These results suggest that WEPO can inhibit cell pyroptosis caused by PEDV and that the Caspase-1 and GSDMD pathways play an important role in this process.

Molecular Dynamics Simulation and Viscosity Analysis of Red Mud-Steel Slag Glass-Ceramics

The preparation of glass-ceramics with red mud and steel slag can not only solve the pollution problem caused by industrial waste slag but also produce economic benefits. It is difficult to analyze the high-temperature melt with the existing test methods, so the simulation experiment with molecular dynamics calculation becomes an important research method. The effects of steel slag content on the microstructure of red mud glass-ceramics were studied by molecular dynamics method. The results show that the binding ability of Si-O, Al-O, and Fe-O decreases with the increase in steel slag content. The number of Si-O-Si bridge oxygen increased gradually, while the number of Al-O-Al, Al-O-Fe, and Fe-O-Fe bridge oxygen decreased significantly. The number of tetrahedrons [SiO4] increased, the number of tetrahedrons [FeO4] and [AlO4] decreased, and the total number of three tetrahedrons decreased. The mean square displacement value of Si4+ and O2- increases first and then decreases, resulting in the viscosity of the system decreasing first and then increasing. The molecular dynamics method is used to analyze the structure of red mud-steel slag glass-ceramics on the microscopic scale, which can better understand the role of steel slag and has guiding significance for the experiment of this kind of glass-ceramics.

Mechanisms of Gravitational Influence on Weld Pool Behavior and Weld Bead Performance in Variable Polarity Plasma Arc Welding across Different Welding Position

This article comprehensively explores the cross-scale effects of gravity on macroscopic flow formation and weld bead formation in variable polarity plasma arc welding. Gravity-induced changes in welding direction were achieved through welding at different spatial positions. The properties of the weld bead were investigated at various spatial locations. Additionally, an elemental tracing technique was employed to study the internal flow behavior of molten metal. In the flat welding position, there is an observable trend of increasing grain size in the welded bead, accompanied by a significant expansion of the coarse grain zone. Consequently, the properties of the weld bead in the flat position are inferior to those achieved in the vertical welding position. This phenomenon can be attributed to the accumulation of molten metal at the exit side of the keyhole, resulting in temperature accumulation. Research indicates that the internal flow within the weld pool plays a critical role in causing this phenomenon. The study's findings reveal the presence of two distinct vortex flow patterns within the weld pool: one aligned with the welding direction and the other directed towards the interior of the weld pool. Particularly noteworthy is the substantial expansion of the flow channel area in the flat welding position, which significantly amplifies the impact of internal flow. This enhanced flow intensity inevitably leads to the increased buildup of molten metal at the keyhole exit side. These studies lay the groundwork for achieving high-quality and controllable spatial-position welding.

Metabolic Engineering of De Novo Pathway for the Production of 2'-Fucosyllactose in Escherichia coli

2'-Fucosyllactose (2'-FL), one of the most abundant oligosaccharides in human milk, has gained increased attention owing to its nutraceutical and pharmaceutical potential. However, limited availability and high-cost of preparation have limited its widespread application and in-depth investigation of its potential functions. Here, a modular pathway engineering was implemented to construct an Escherichia coli strain to improve the biosynthesis titer of 2'-FL. Before overexpression of manB, manC, gmd, wcaG, and heterologous expression of futC, genes wcaJ and lacZ encoding UDP-glucose lipid carrier transferase and β-galactosidase, respectively, were inactivated from E. coli BL21 (DE3) with the CRISPR-Cas9 system, which inhibited the production of 2'-FL. The results showed that final shake flask culture yielded a 3.8-fold increase in 2'-FL (0.98 g/L) from the engineered strain ELC07. Fed-batch fermentation conditions were optimized in a 3-L bioreactor. The highest titer of 2'-FL (18.22 g/L) was obtained, corresponding to a yield of 0.25 g/g glycerol and a substrate conversion of 0.88 g/g lactose.

Importin β1 Mediates Nuclear Entry of EIN2C to Confer the Phloem-Based Defense against Aphids

Ethylene Insensitive 2 (EIN2) is an integral membrane protein that regulates ethylene signaling towards plant development and immunity by release of its carboxy-terminal functional portion (EIN2C) into the nucleus. The present study elucidates that the nuclear trafficking of EIN2C is induced by importin β1, which triggers the phloem-based defense (PBD) against aphid infestations in Arabidopsis. In plants, IMPβ1 interacts with EIN2C to facilitate EIN2C trafficking into the nucleus, either by ethylene treatment or by green peach aphid infestation, to confer EIN2-dependent PBD responses, which, in turn, impede the phloem-feeding activity and massive infestation by the aphid. In Arabidopsis, moreover, constitutively expressed EIN2C can complement the impβ1 mutant regarding EIN2C localization to the plant nucleus and the subsequent PBD development in the concomitant presence of IMPβ1 and ethylene. As a result, the phloem-feeding activity and massive infestation by green peach aphid were highly inhibited, indicating the potential value of EIN2C in protecting plants from insect attacks.

Simultaneously Enhancing the Flame Retardancy, Water Resistance, and Mechanical Properties of Flame-Retardant Polypropylene via a Linear Vinyl Polysiloxane-Coated Ammonium Polyphosphate

It is challenging to improve the water resistance, flame retardancy, mechanical performance, and balance of halogen-free flame-retardant polypropylene (PP) composites. For this purpose, a linear vinyl polysiloxane (PD) was synthesized and then self-crosslinked under benzoyl peroxide to prepare surface-coated ammonium polyphosphate (APP@PD). Apparently, this linear vinyl polysiloxane self-crosslinking coating strategy was completely different from the commonly used sol-gel-coated APP with silane monomers. After coating, the water contact angles (WCA) of APP and APP@PD were 26.8° and 111.7°, respectively, showing high hydrophobicity. More importantly, PP/APP@PD/dipentaerythritol (DPER) showed a higher limiting oxygen index (LOI) and better UL-94 V-0 rate in comparison with PP/APP/DPER composites. After water immersion at 70 °C for 168 h, only PP/APP@PD/DPER kept the UL-94 V-0 rate and lowered the deterioration of the LOI, reflecting the better water-resistance property of APP@PD. Consistently, the cone calorimeter test results displayed a 26.2% and 16.7% reduction in peak heat release rate (PHRR) and total smoke production (TSP), respectively. Meanwhile, the time to peak smoke production rate (T_PSPR) increased by 90.2%. The interfacial free energy (IFE) between APP@PD and PP was calculated to evaluate the interfacial interaction between PP and APP@PD. A reduction of 84.2% in the IFE between APP@PD and PP is responsible for the improvement in compatibility and the increase in flame retardancy, water resistance, and mechanical properties of the composites.

Sublethal Effects of Neonicotinoid Insecticides on the Development, Body Weight and Economic Characteristics of Silkworm

Silkworm Bombyx mori (L.) (Lepidoptera: Bombycidae) is a critical insect for silk producers, but the inappropriate application of insecticides negatively affects the physiology and behavior of silkworms. This study found that the effects of neonicotinoid insecticides applied using two spraying methods on the growth and development of silkworms were different: the median lethal concentration (LC₅₀) values of two pesticides applied using the leaf-dipping method were 0.33 and 0.83 mg L^-1 and those of two pesticides applied using the quantitative spraying method were 0.91 and 1.23 mg kg^-1. The concentration of pesticides on the mulberry leaves did not decrease after their application using the quantitative spraying method, and a uniform spraying density was observed after the mulberry leaves were air-dried (no liquid) under realistic conditions. We then treated silkworms with the quantitative spraying method and leaf-dipping method. The treatment of silkworm larvae with imidacloprid and thiamethoxam at sublethal concentrations significantly prolonged the development time and significantly decreased the weight and pupation rate, as well as economic indicators of enamel layers and sputum production. Thiamethoxam treatment significantly increased the activities of carboxylesterase (CarE) and glutathione-S-transferase (GST). The activity of CarE and GST increased, decreased, and then increased, and the highest activity was detected on the 10th and 12th days. Thiamethoxam exposure significantly elevated the transcription levels of CarE-11, GSTe3 and GSTz2 and induced DNA damage in hemocytes. This study confirmed that the quantitative spray method is more stable than the leaf-dipping method. Moreover, imidacloprid and thiamethoxam treatment affected the economy and indexes of silkworms and induced changes in detoxification enzymes and DNA damage in silkworms. These results provide a basis for understanding the mechanism of the sublethal effects of insecticides on silkworms.

Multi-level metabolic engineering of Escherichia coli for high-titer biosynthesis of 2'-fucosyllactose and 3-fucosyllactose

Fucosyllactoses (FL), including 2'-fucosyllactose (2'-FL) and 3-fucosyllactose (3-FL), have garnered considerable interest for their value in newborn formula and pharmaceuticals. In this study, an engineered Escherichia coli was developed for high-titer FL biosynthesis by introducing multi-level metabolic engineering strategies, including (1) individual construction of the 2'/3-FL-producing strains through gene combination optimization of the GDP-L-fucose module; (2) screening of rate-limiting enzymes (α-1,2-fucosyltransferase and α-1,3-fucosyltransferase); (3) analysis of critical intermediates and inactivation of competing pathways to redirect carbon fluxes to FL biosynthesis; (4) enhancement of the catalytic performance of rate-limiting enzymes by the RBS screening, fusion peptides and multi-copy gene cloning. The final strains EC49 and EM47 produced 9.36 g/L for 2'-FL and 6.28 g/L for 3-FL in shake flasks with a modified-M9CA medium. Fed-batch cultivations of the two strains generated 64.62 g/L of 2'-FL and 40.68 g/L of 3-FL in the 3-L bioreactors, with yields of 0.65 mol 2'-FL/mol lactose and 0.67 mol 3-FL/mol lactose, respectively. This research provides a viable platform for other high-value-added compounds production in microbial cell factories.

Mobile robot path planning with reformative bat algorithm

Mobile robot path planning has attracted much attention as a key technology in robotics research. In this paper, a reformative bat algorithm (RBA) for mobile robot path planning is proposed, which is employed as the control mechanism of robots. The Doppler effect is applied to frequency update to ameliorate RBA. When the robot is in motion, the Doppler effect can be adaptively compensated to prevent the robot from prematurely converging. In the velocity update and position update, chaotic map and dynamic disturbance coefficient are introduced respectively to enrich the population diversity and weaken the limitation of local optimum. Furthermore, Q-learning is incorporated into RBA to reasonably choose the loudness attenuation coefficient and the pulse emission enhancement coefficient to reconcile the trade-off between exploration and exploitation, while improving the local search capability of RBA. The simulation experiments are carried out in two different environments, where the success rate of RBA is 93.33% and 90%, respectively. Moreover, in terms of the results of success rate, path length and number of iterations, RBA has better robustness and can plan the optimal path in a relatively short time compared with other algorithms in this field, thus illustrating its validity and reliability. Eventually, by the aid of the Robot Operating System (ROS), the experimental results of real-world robot navigation indicate that RBA has satisfactory real-time performance and path planning effect, which can be considered as a crucial choice for dealing with path planning problems.

Optimal Design of Multiple Floating Rings for 3D Large-Area Trench Electrode Silicon Detector

The 3D electrode silicon detector eliminates the limit of chip thickness, so it can reduce the electrode spacing (small area) and effectively improve the radiation hardness. In order to expand the application range of the 3D electrode detector, we first propose a 3D large-area silicon detector with a large sensitive volume, and realize multiple floating rings on the upper and lower surfaces of the detector. Due to the influence of different charge states and energy levels in the Si-SiO2 interface system, the top and bottom of the 3D P+ electrode are more prone to avalanche breakdown in the 3D large-area detector before the detector is completely depleted or the carrier saturation drift velocity is reached. Moreover, the electric field distribution becomes very uneven under the influence of the oxide charge, resulting in non-equilibrium carriers that cannot drift in the optimal path parallel to the detector surface. In this paper, the effect of floating rings on the performance of a 3D large-area silicon detector is studied by TCAD simulation. It can increase avalanche breakdown voltage by 14 times in a non-irradiated environment, and can work safely in a moderate irradiated environment. The charge collection efficiency can be effectively improved by optimizing the drift path.

Prognostic Significance and Therapeutic Target of CXC Chemokines in the Microenvironment of Lung Adenocarcinoma

Background

Lung adenocarcinoma (LUAD) is one of the most important subtypes of lung cancer and has a high morbidity and mortality. Inflammatory CXC chemokines in tumor microenvironment can stimulate tumor growth, invasion, and metastasis, affecting the prognosis of patients. However, the differential expression profiles, prognostic values, and specific mechanisms of the CXC chemokine family in LUAD have not been clarified.

Methods

Transcriptome expression profile data were extracted from TIMER and TCGA. GEPIA was used to compare the relationship between CXC chemokines and clinicopathologic parameters. The prognostic analysis was performed using a Kaplan–Meier curve in GEPIA. LinkedOmics and TRRUST were applied to conduct the enrichment analysis of the regulatory networks containing the kinase targets, miRNA targets, and transcriptional factor targets. The characteristics of immune infiltration and immune-related clinical outcomes were evaluated with TIMER algorithms. Single-cell RNA sequencing localization analysis of genes as prognostic biomarkers were performed by PanglaoDB.

Results

Nine differentially expressed genes were identified in LUAD compared to normal tissues. Aberrant expression of CXCL2 (P =0.0017), CXCL13 (P= 0.0271), CXCL16 (P= 0.016), and CXCL17 (P= 2.14e-5) was significantly correlated with clinical cancer stage. Furthermore, patients with low gene transcription of CXCL 7 (P = 0.017) and high expression of CXCL 17 (P = 0.00045) had a better prognosis in LUAD. We also found that immune cell infiltration was significantly correlated with LUAD microenvironment mediated by CXC chemokines. Cox proportional hazard model test was conducted and indicated that B cell infiltration could prolong the survival of the LUAD patients. CXCL17 exerted anti-tumors effect through pulmonary alveolar type II cells according to single-cell analysis.

Conclusion

Our research identified the aberrant expression profiles and prognostic biomarkers of CXC chemokines in LUAD. This detailed analysis of the regulatory factor networks for CXC chemokine gene expression may provide novel insights for selecting potential immunotherapeutic targets.

Stress memory gene FaHSP17.8-CII controls thermotolerance via remodeling PSII and ROS signaling in tall fescue

High temperature is the most limiting factor in the growth of cool-season turfgrass. To cope with high-temperature stress, grass often adopt a memory response by remembering one past recurring stress and preparing a quicker and more robust reaction to the next stress exposure. However, little is known about how stress memory genes regulate the thermomemory response in cool-season turfgrass. Here, we characterized a transcriptional memory gene, Fa-heat shock protein 17.8 Class II (FaHSP17.8-CII) in a cool-season turfgrass species, tall fescue (Festuca arundinacea Schreb.). The thermomemory of FaHSP17.8-CII continued for more than 4 d and was associated with a high H3K4me3 level in tall fescue under heat stress (HS). Furthermore, heat acclimation or priming (ACC)-induced reactive oxygen species (ROS) accumulation and photosystem II (PSII) electron transport were memorable, and this memory response was controlled by FaHSP17.8-CII. In the fahsp17.8-CII mutant generated using CRISPR/Cas9, ACC+HS did not substantially block the ROS accumulation, the degeneration of chloroplast ultra-structure, and the inhibition of PSII activity compared with HS alone. However, overexpression of FaHSP17.8-CII in tall fescue reduced ROS accumulation and chloroplast ultra-structure damage, and improved chlorophyll content and PSII activity under ACC+HS compared with that HS alone. These findings unveil a FaHSP17.8-CII-PSII-ROS module regulating transcriptional memory to enhance thermotolerance in cool-season turfgrass.

An improved clear cell renal cell carcinoma stage prediction model based on gene sets

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal cell carcinoma and accounts for cancer-related deaths. Survival rates are very low when the tumor is discovered in the late-stage. Thus, developing an efficient strategy to stratify patients by the stage of the cancer and inner mechanisms that drive the development and progression of cancers is critical in early prevention and treatment.

RESULTS

In this study, we developed new strategies to extract important gene features and trained machine learning-based classifiers to predict stages of ccRCC samples. The novelty of our approach is that (i) We improved the feature preprocessing procedure by binning and coding, and increased the stability of data and robustness of the classification model. (ii) We proposed a joint gene selection algorithm by combining the Fast-Correlation-Based Filter (FCBF) search with the information value, the linear correlation coefficient, and variance inflation factor, and removed irrelevant/redundant features. Then the logistic regression-based feature selection method was used to determine influencing factors. (iii) Classification models were developed using machine learning algorithms. This method is evaluated on RNA expression value of clear cell renal cell carcinoma derived from The Cancer Genome Atlas (TCGA). The results showed that the result on the testing set (accuracy of 81.15% and AUC 0.86) outperformed state-of-the-art models (accuracy of 72.64% and AUC 0.81) and a gene set FJL-set was developed, which contained 23 genes, far less than 64. Furthermore, a gene function analysis was used to explore molecular mechanisms that might affect cancer development.

CONCLUSIONS

The results suggested that our model can extract more prognostic information, and is worthy of further investigation and validation in order to understand the progression mechanism.

Construction of Dimeric Drug-Loaded Polymeric Micelles with High Loading Efficiency for Cancer Therapy

Polymeric micelles (PMs) have been applied widely to transport hydrophobic drugs to tumor sites for cancer treatment. However, the low load efficiency of the drug in the PMs significantly reduces the therapeutic efficiency. We report here that disulfide-linked camptothecin (CPT) as a kind of dimeric drug can be effectively embedded in the core of poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) (PCL-PEG-PCL) PMs for improving drug-loading efficiency, and PEG can be used as a hydrophilic shell. Moreover, the dimeric CPT-loaded PCL-PEG-PCL PMs exhibited excellent solubility in phosphate-buffered saline (PBS) media and significant cytotoxicity to cancer cells.