The functional role of P2 purinergic receptors in the progression of gastric cancer.

Studies have confirmed that P2 purinergic receptors (P2X receptors and P2Y receptors) expressed in gastric cancer (GC) cells and GC tissues and correlates with their function. Endogenous nucleotides including ATP, ADP, UTP, and UDP, as P2 purinergic receptors activators, participate in P2 purinergic signal transduction pathway. These activated P2 purinergic receptors regulate the progression of GC mainly by mediating ion channels and intracellular signal cascades. It is worth noting that there is a difference in the expression of P2 purinergic receptors in GC, which may play different roles in the progression of GC as a tumor promoting factor or a tumor suppressor factor. Among them, P2 × 7, P2Y2 and P2Y6 receptors have certain clinical significance in patients with GC and may be used as biological molecular markers for the prediction of patients with GC. Therefore, in this paper, we discuss the functional role of nucleotide / P2 purinergic receptors signal axis in regulating the progression of GC and that these P2 purinergic receptors may be used as potential molecular targets for the prevention and treatment of GC.

Dispersive Solid-Phase Extraction and Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry-A Rapid and Accurate Method for Detecting 10 Macrolide Residues in Aquatic Products.

The amount of macrolide (MAL) residues in aquatic products, including oleandomycin (OLD), erythromycin (ERM), clarithromycin (CLA), azithromycin (AZI), kitasamycin (KIT), josamycin (JOS), spiramycin (SPI), tilmicosin (TIL), tylosin (TYL), and roxithromycin (ROX), was determined using solid-phase extraction and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The residues were extracted with 1% ammonia acetonitrile solution and purified by neutral alumina adsorption. Chromatographic separation was completed on an ACQUITY UPLC BEH C18 column with acetonitrile-0.1% formic acid aqueous solution as the mobile phase, and mass spectrometry detection was performed by multiple reaction monitoring scanning with the positive mode in an electrospray ion source (ESI+). Five isotopically labeled compounds were used as internal standards for quality control purposes. The findings indicated that across the mass concentration span of 1.0-100 µg/L, there was a strong linear correlation (R2 > 0.99) between the concentration and instrumental response for the 10 MALs. The limit of detection of UPLC-MS/MS was 0.25-0.50 µg/kg, and the limit of quantitation was 0.5-1.0 µg/kg. The added recovery of blank matrix samples at standard gradient levels (1.0, 5.0, and 50.0 µg/kg) was 83.1-116.6%, and the intra-day precision and inter-day precisions were 3.7 and 13.8%, respectively. The method is simple and fast, with high accuracy and good repeatability, in line with the requirements for accurate qualitative and quantitative analysis of the residues for 10 MALs in aquatic products.

The predictive value of systemic immune-inflammatory markers before and after treatment for pathological complete response in patients undergoing neoadjuvant therapy for breast cancer: a retrospective study of 1994 patients.

PURPOSE: Systemic immune-inflammatory markers have a certain predictive role in pathological complete response (pCR) after neoadjuvant treatment (NAT) in breast cancer. However, there is a lack of research exploring the predictive value of markers after treatment. METHODS: This retrospective study collected data from 1994 breast cancer patients who underwent NAT. Relevant clinical and pathological characteristics were included, and pre- and post-treatment complete blood cell counts were evaluated to calculate four systemic immune-inflammatory markers: neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), and systemic immune-inflammation index (SII). The optimal cutoff values for these markers were determined using ROC curves, and patients were classified into high-value and low-value groups based on these cutoff values. Univariate and multivariate logistic regression analyses were conducted to analyze factors influencing pCR. The factors with independent predictive value were used to construct a nomogram. RESULTS: After NAT, 383 (19.2%) patients achieved pCR. The area under the ROC curve is generally larger for post-treatment markers compared to pre-treatment markers. Pre-treatment NLR and PLR, as well as post-treatment LMR and SII, were identified as independent predictive factors for pCR, along with Ki-67, clinical tumor stage, clinical lymph node stage, molecular subtype, and clinical response. Higher pre-NLR (OR = 1.320; 95% CI 1.016-1.716; P = 0.038), pre-PLR (OR = 1.474; 95% CI 1.058-2.052; P = 0.022), post-LMR (OR = 1.532; 95% CI 1.175-1.996; P = 0.002), and lower post-SII (OR = 0.596; 95% CI 0.429-0.827; P = 0.002) are associated with a higher likelihood of achieving pCR. The established nomogram had a good predictive performance with an area under the ROC curve of 0.754 (95% CI 0.674-0.835). CONCLUSION: Both pre- and post-treatment systemic immune-inflammatory markers have a significant predictive role in achieving pCR after NAT in breast cancer patients. Indeed, it is possible that post-treatment markers have stronger predictive ability compared to pre-treatment markers.

Bacillus subtilis YZ-1 surfactins are involved in effective toxicity against agricultural pests.

BACKGROUND: Insect pests negatively affect crop quality and yield. The excessive use of chemical pesticides has serious impacts on the environment and food safety. Therefore, development of effective management strategies in the form of bio-agents have important agricultural applications. Tenebrio molitor, a storage pest, causes losses of grains, medicinal materials, and various agricultural and related products in the warehouse. Bacillus subtilis YZ-1 isolated from naturally deceased Pieris rapae has been found to exhibit significant toxicity against T. molitor. RESULTS: Treatment with B. subtilis YZ-1 fermentation broth resulted in a 90-95% mortality rate of T. molitor within 36 h post-treatment, indicating some active substances may have insecticidal activity in the bacterial supernatant. A bioactivity-guided fractionation method was used to isolate the insecticidal compounds from YZ-1, which led to the identification of surfactins. Additionally, a surfactin deletion mutant YZ-1△srfAA was constructed and the surfactin production by the mutant YZ-1△srfAA was verified through liquid chromatography-mass spectrometry (LC-MS). Further, YZ-1△srfAA exhibited loss of insecticidal activity against T. molitor, Plutella xylostella and Achelura yunnanensis. The insecticidal activity and surfactins contents of several strains of Bacillus sp. were also tested and correlation was found between varying surfactins yield and insecticidal activity exhibited by different strains. CONCLUSION: Conclusively, our results suggest that B. subtilis YZ-1 may provide a novel approach for plant protection against agricultural pests. © 2023 Society of Chemical Industry.

Enhanced far infrared emissivity, UV protection and near-infrared shielding of polypropylene composites via incorporation of natural mineral for functional fabric development.

Far infrared radiation in the range of 4-20 µm has been showed to have biological and health benefits to the human body. Therefore, incorporating far-infrared emissivity additives into polymers and/or fabrics hold promise for the development of functional textiles. In this study, we incorporated nine types of natural minerals into polypropylene (PP) film and examined their properties to identify potential candidates for functional textiles and apparels. The addition of 2% mineral powders into PP film increased the far-infrared emissivity (5-14 µm) by 7.65%-14.48%. The improvement in far-infrared emissivity within the range of 5-14 µm, which overlaps with the peak range of human skin radiation at 8-14 µm, results in increased absorption efficiency, and have the potential to enhance thermal and biological effects. Moreover, the incorporation of mineral powders in PP films exhibited favorable ultraviolet (UV) protection and near-infrared (NIR) shielding properties. Two films, specifically those containing red ochre and hematite, demonstrated excellent UV protection with a UPF rating of 50+ and blocked 99.92% and 98.73% of UV radiation, respectively. Additionally, they showed 95.2% and 93.2% NIR shielding properties, compared to 54.1% NIR shielding properties of PP blank films. The UV protection and NIR shielding properties offered additional advantages for the utilization of polymer composite with additives in the development of sportswear and other outdoor garments. The incorporation of minerals could absorb near-IR radiation and re-emit them at longer wavelength in the mid-IR region. Furthermore, the incorporation of minerals significantly improved the heat retention of PP films under same heat radiation treatment. Notably, films with red ochre and hematite exhibited a dramatic temperature increase, reaching 2.5 and 3.2 times the temperature increase of PP films under same heat radiation treatment, respectively (46.8 °C and 59.9 °C higher than the temperature increase of 20.9 °C in the PP film). Films with additives also demonstrated lower thermal effusivity than PP blank films, indicating superior heat insulation properties. Therefore, polypropylene films with mineral additives, particularly those containing red ochre and hematite, showed remarkable heat capacity, UV-protection, NIR-shielding properties and enhanced far infrared emissivity, making them promising candidates for the development of functional textiles.

Bacillus amyloliquefaciens AK-12 Helps Rapeseed Establish a Protection against Brevicoryne brassicae.

Aphids are a serious threat to rapeseed (Brassica napus L.) production, and cause unmanageable loss. Therefore, effective prevention and management strategies are urgently required to avoid losses. Bacillus amyloliquefaciens AK-12 isolated from a dead aphid with aphicidal activity was tagged with a green fluorescent protein through a natural transformation. The transformed strains were checked for stability and growth, and the best-performing strain was tested for its colonization inside and outside the rapeseed plant. The stability of AK-12-GFP reached more than 95%, and the growth curve was consistent with that of AK-12. After 30 days of treatment, the colonization of 1 × 106 CFU/g was recorded in rapeseed leaves. Interestingly, AK-12 reduced the aphid transmission rate compared with the control and improved the growth of the rapeseed seedlings. Meanwhile, the AK-12 strain also exhibited phosphorus, potassium-solubilizing, and nitrogen-fixing activity, and produced 2.61 µg/mL of IAA at 24 h. Regulation in the activity of four enzymes was detected after the AK-12 treatment. Phenylalanine ammonia lyase (PAL) was recorded at a maximum of 86.84 U/g after 36 h, and catalase (CAT) decreased after 48 h; however, peroxidase (POD) and polyphenol oxidase (PPO) reached the maximum within 12 h of AK-12 application. Additionally, important resistance genes related to these enzymes were upregulated, indicating the activation of a defense response in the rapeseed against aphids. In conclusion, defense enzymes and defense-related gene activation could improve the pest resistance in rapeseed, which has good application prospects for the future to be developed into biopesticide.

One Pot Synthesis of Nanofiber-Coated Magnetic Composites as Magnetic Dispersive Solid-Phase Extraction Adsorbents for Rapid Determination of Tetracyclines in Aquatic Food Products.

A magnetic adsorbent based on a C-nanofiber (Fe3O4@C-NFs) nanocomposite was synthesized using a simple one-pot co-precipitation method. The characterized results showed that the obtained C-nanofiber-coated magnetic nanoparticles had many attractive features such as a large specific surface area and a highly interwoven and branched mesoporous structure, as well as distinguished magnetism. The nanocomposite was then used as an adsorbent in the magnetic solid phase extraction (MSPE) of four typical tetracyclines (oxytetracycline, tetracycline, chlortetracycline, and doxycycline) in aquatic products. The TCs in the extract were determined using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Experimental variables of MSPE, including the sorbent amount, pH condition, adsorption and desorption time, and desorption solvent, were investigated and optimized systematically. The method validation indicated that the developed method showed good linearity (R2 > 0.995) in the range of 1.0-200 ng/mL. The average recoveries at the spiked levels ranged from 90.7% to 102.7% with intra-day and inter-day relative standard deviations (RSDs, n = 6) ranging from 3.72% to 8.17% and 4.20% to 9.69%, respectively. The limit of detection (LOD) and limit of quantification (LOQ) for the four kinds of TCs were 0.7 µg/kg and 2.0 µg/kg, respectively. Finally, MSPE based on C-nanofiber-coated magnetic nanoparticles was successfully applied to TC analysis in real aquatic products (grass carp, large yellow croaker, snakehead, mandarin fish, Penaeus vannamei, swimming crab, etc.). Compared with traditional extraction methods, the proposed method for TC analysis in aquatic products is more sensitive, effective, recyclable, and environmentally friendly.

ATP ion channel P2X7 receptor as a regulatory molecule in the progression of colorectal cancer.

Large amounts of adenosine triphosphate (ATP), a natural P2X7 receptor activator, are released during colorectal carcinogenesis. P2X7 receptor activation regulates the activity of colorectal cancer (CRC) cells by mediating intracellular signal transduction. Importantly, the opening and activation of membrane pores of P2X7 receptor are different, which can play a dual role in promoting or inhibiting the progression of CRC. These can also depend on P2X7 receptor to regulate the activities of immune cells in the microenvironment, play the functions of immune regulation, immune escape and immune monitoring. While the use of P2X7 receptor antagonists (such as BBG, A438079 and A740003) can play a certain inhibitory pharmacological role on the activity of CRC. Therefore, in this paper, the mechanism and immunomodulatory function of P2X7 receptor involved in the progression of CRC were discussed. Moreover, we discussed the effect of antagonizing the activity of P2X7 receptor on the progression of CRC. So P2X7 receptor may be a new pharmacological molecular target for the treatment of CRC.

Determination of Pentachlorophenol in Seafood Samples from Zhejiang Province Using Pass-Through SPE-UPLC-MS/MS: Occurrence and Human Dietary Exposure Risk.

Pentachlorophenol (PCP) has attracted wide attention due to its high toxicity, persistence, and bioaccumulation. In this study, a sensitive UPLC-MS/MS method for the determination of PCP in seafood samples was developed and validated. The samples were ultrasonic extracted with acetonitrile containing 1% acetic acid-acetonitrile and followed by using a pass-through solid-phase extraction (SPE) cleanup on Captiva EMR-Lipid cartridges. The linearity of this method ranged from 1 to 1000 µg/L, with regression coefficients of >0.99. The detection limit and quantitation limit were 0.5 µg/kg and 1.0 µg/kg, respectively. The recoveries in different types of seafood samples ranged from 86.4% to 102.5%, and the intra-day and inter-day relative standard deviations (RSDs) were 3.7% to 11.2% and 2.9% to 12.1%, respectively (n = 6). Finally, the method has been successfully utilized for the screening of PCP in 760 seafood samples from Zhejiang Province. PCP was detected in 5.8% of all seafood samples, with the largest portion of detections found in shellfish, accounting for approximately 60% of the total. The average concentrations detected ranged from 1.08 to 21.49 µg/kg. The non-carcinogenic risk indices for adults and children who consume PCP ranged from 10-4 to 10-3 magnitudes. All of these indices stayed significantly below 1, implying that the health risk from PCP in marine organisms to humans is minimal.

Causal effects of systemic inflammatory regulators on chronic kidney diseases and renal function: a bidirectional Mendelian randomization study.

Background: While targeted systemic inflammatory modulators show promise in preventing chronic kidney disease (CKD) progression, the causal link between specific inflammatory factors and CKD remains uncertain. Methods: Using a genome-wide association study of 41 serum cytokines from 8,293 Finnish individuals, we conducted a bidirectional two-sample Mendelian randomization (MR) analysis. In addition, we genetically predicted causal associations between inflammatory factors and 5 phenotypes, including CKD, estimated glomerular filtration rate (eGFR), dialysis, rapid progression of CKD, and rapid decline in eGFR. Inverse variance weighting (IVW) served as the primary MR method, while MR-Egger, weighted median, and MR-pleiotropy residual sum and outlier (MR-PRESSO) were utilized for sensitivity analysis. Cochrane's Q test for heterogeneity. Leave-one-out method ensured stability of MR results, and Bonferroni correction assessed causal relationship strength. Results: Seventeen cytokines were associated with diverse renal outcomes. Among them, after Bonferroni correction test, higher tumor necrosis factor alpha levels were associated with a rapid decrease in eGFR (OR = 1.064, 95% CI 1.028 - 1.103, P = 0.001), higher interleukin-4 levels were associated with an increase in eGFR (ß = 0.003, 95% CI 0.001 - 0.005, P = 0.002), and higher growth regulated oncogene alpha (GROα) levels were associated with an increased risk of CKD (OR=1.035, 95% CI 1.012 - 1.058, P = 0.003). In contrast, genetic susceptibility to CKD was associated with an increase in GROa, and a decrease in eGFR may lead to an increase in stem cell factor. We did not find the presence of horizontal pleiotropy during the analysis. Conclusion: We discovered causally related inflammatory factors that contribute to the initiation and progression of CKD at the genetic prediction level.

Integrated metabolome and transcriptome analyses provide insight into the effect of red and blue LEDs on the quality of sweet potato leaves.

Red and blue light-emitting diodes (LEDs) affect the quality of sweet potato leaves and their nutritional profile. Vines cultivated under blue LEDs had higher soluble protein contents, total phenolic compounds, flavonoids, and total antioxidant activity. Conversely, chlorophyll, soluble sugar, protein, and vitamin C contents were higher in leaves grown under red LEDs. Red and blue light increased the accumulation of 77 and 18 metabolites, respectively. Alpha-linoleic and linolenic acid metabolism were the most significantly enriched pathways based on Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. A total of 615 genes were differentially expressed between sweet potato leaves exposed to red and blue LEDs. Among these, 510 differentially expressed genes were upregulated in leaves grown under blue light compared with those grown under red light, while the remaining 105 genes were expressed at higher levels in the latter than in the former. Among the KEGG enrichment pathways, blue light significantly induced anthocyanin and carotenoid biosynthesis structural genes. This study provides a scientific reference basis for using light to alter metabolites to improve the quality of edible sweet potato leaves.

An Automated Solid-Phase Extraction-UPLC-MS/MS Method for Simultaneous Determination of Sulfonamide Antimicrobials in Environmental Water.

The large-scale use of sulfonamide antimicrobials in human and veterinary medicine has seriously endangered the ecological environment and human health. The objective of this study was to develop and validate a simple and robust method for the simultaneous determination of seventeen sulfonamides in water using ultra-high performance liquid chromatography-tandem mass spectrometry coupled with fully automated solid-phase extraction. Seventeen isotope-labeled internal standards for sulfonamides were used to correct matrix effects. Several parameters affecting extraction efficiency were systematically optimized, and the enrichment factors were up to 982-1033 and only requiring about 60 min per six samples. Under the optimized conditions, this method manifested good linearity (0.05-100 µg/L), high sensitivity (detection limits: 0.01-0.05 ng/L), and satisfactory recoveries (79-118%) with acceptable relative standard deviations (0.3-14.5%, n = 5). The developed method can be successfully utilized for the determination of 17 sulfonamides in pure water, tap water, river water, and seawater. In total, six and seven sulfonamides were detected in river water and seawater, respectively, with a total concentration of 8.157-29.676 ng/L and 1.683-36.955 ng/L, respectively, and sulfamethoxazole was the predominant congener.

SARS-CoV-2 spike host cell surface exposure promoted by a COPI sorting inhibitor.

Via an insufficient coat protein complex I (COPI) retrieval signal, the majority of SARS-CoV-2 spike (S) is resident in host early secretory organelles and a tiny amount is leaked out in cell surface. Only surface-exposed S can be recognized by B cell receptor (BCR) or anti-S therapeutic monoclonal antibodies (mAbs) that is the trigger step for B cell activation after S mRNA vaccination or infected cell clearance by S mAbs. Now, a drug strategy to promote S host surface exposure is absent. Here, we first combined structural and biochemical analysis to characterize S COPI sorting signals. A potent S COPI sorting inhibitor was then invented, evidently capable of promoting S surface exposure and facilitating infected cell clearance by S antibody-dependent cellular cytotoxicity (ADCC). Importantly, with the inhibitor as a probe, we revealed Omicron BA.1 S is less cell surface exposed than prototypes because of a constellation of S folding mutations, possibly corresponding to its ER chaperone association. Our findings not only suggest COPI is a druggable target against COVID-19, but also highlight SARS-CoV-2 evolution mechanism driven by S folding and trafficking mutations.

First report of Aloe root and stem rot caused by Phytophthora palmivora in Yunnan Province, China.

Aloe genus plants are perennial evergreen herb belonging to Liliaceae family which is widely used in food, medicine, beauty, and health care (Kumar et al. 2019). In August 2021, symptoms of root and stem rot was observed in approximately 20% of Aloe vera plantings in Yuanjiang County, Yunnan Province, China (23° 64' 53" N, 101° 99' 84" E). The most typical symptoms were stem and root rot, browning and necrosis of vascular tissues, gradual greening, and reddish-browning of leaves from bottom to top, abscission, and eventual plant death (Fig. S1). Therefore, to isolate and identify the pathogen, the plants showing the above symptoms were collected. The plant tissues were cut from the edges of root and stem lesions, followed by disinfection with 75% ethanol for 1 min, rinsed three times with sterilized distilled water, and cut into 3 × 3 mm small squares after excision of marginal tissues. The tissues were transferred to the oomycetes selective medium (Liu et al. 2022) and incubated at 28 °C in the dark for 3~5 days, and suspected colonies were purified. The colonies were then inoculated onto potato dextrose agar (PDA), V8-juice agar (V8), and oatmeal agar (OA) medium plates for morphological characteristics. Finally, 18 isolates with the same colonial and morphological characteristics were obtained from 30 lesioned tissue and one of them was named as ARP1. On PDA, V8 and OA medium plates, the ARP1 colonies were white. On PDA plate, the mycelia were dense and the colonies were petal-like; on V8 plate, the mycelia were cashmere and the colonies were radial or star-like. Whereas, on OA plate, the mycelia were cotton-like and the colonies were fluffy and radial (Fig. S2 A~C). Mycelium did not have septum with high branching and swelling. Sporangia were abundant, semi-papillate, varying in shape from ovoid-ellipsoid to long-ellipsoid, 18-26 × 45-63 µm (average: 22 × 54 µm, n = 30), sporangia released numerous zoospores from the papillate after maturation. The chlamydospores were spherical, 20-35 µm in diameter (average: 27.5 µm, n = 30) (Fig. S2 D~F). These morphological features were like those of the pathogenic species of the oomycetes (Chen et al. 2022). For the molecular characterization, the genomic DNA of the isolate was extracted using the cetyl trimethyl ammonium bromide method, and the translation elongation factor 1α (tef-1α) (Stielow et al. 2015), ß-tubulin (ß-tub) (Kroon et al. 2004) and internal transcribed spacer (ITS) (White et al. 1990) of isolated strain ARP1 were amplified using primer pairs EF1-1018F/EF1-1620R, TUBUF2/TUBUR1 and ITS1/ITS4, respectively. The tef-1α, ß-tub genes and ITS region of ARP1 were directly sequenced and their sequence information was deposited in GenBank under accession numbers OQ506129, OQ506127 and OQ449628. ARP1 was clustered on the same evolutionary branch with Phytophthora palmivora (Fig. S3). To confirm the pathogenicity of ARP1, the main root of A. vera was wounded to 1 cm long and 2 mm deep with a scalpel blade followed by inoculation with 50 ml suspension of ARP1 zoospores at a concentration of 1 × 106 spores / ml per potted plant, and an equal volume of water as control. All inoculated plants were placed in the greenhouse at 28°C, 12 h / 12 h light / dark. After 15 dpi, the inoculated plants showed typical symptoms of wilted and drooping leaves and stem and root rot, same as observed in the field condition (Fig. S4). After inoculation with ARP1, a strain with the same morphological and molecular characteristics as the original isolate was re-isolated, confirming Koch's postulates. To our knowledge, this is the first report of P. palmivora causing root and stem rot of A. vera in the study region. This disease could be a potential risk for aloe production and therefore appropriate management measures should be taken.

Hexagonal Sb Nanocrystals as High-Capacity and Long-Cycle Anode Materials for Sodium-Ion Batteries.

Antimony (Sb) is regarded as a promising anode material for sodium ion batteries (SIBs) on account of its high theoretical specific capacity (∼660 mAh g-1) and low cost. However, the large volume expansion (∼390%) during charging has inhibited its practical application. Herein, hexagonal Sb nanocrystals encapsulated by P/N-co-doped carbon nanofibers (Sb@P-N/C) were prepared using a low-cost but mass-produced electrospinning method. The as-prepared Sb@P-N/C, used as anode material for SIBs, exhibits unexpected cycling stability and rate capability, with 500.1 mAh g-1 at 50 mA g-1 after 200 cycles and 295.6 mAh g-1 at 500 mA g-1 after 400 cycles. Especially, the full battery fabricated by Na (Ni1/3Fe1/3Mn1/3) O2 || Sb@P-N/C possesses a reversible specific capacity of 66.8 mAh g-1 at 50 mA g-1 over 60 cycles. This simple and low-cost fabrication technology combined with unique crystal morphology offers new strategies for the advancement of sodium ion batteries (SIBs) in energy storage and electrical transportation.

Biocontrol of plant pathogens in omics era-with special focus on endophytic bacilli.

Nearly all plants and their organs are inhabited by endophytic microbes which play a crucial role in plant fitness and stress resilience. Harnessing endophytic services can provide effective solutions for a sustainable increase in agriculture productivity and can be used as a complement or alternative to agrochemicals. Shifting agriculture practices toward the use of nature-based solutions can contribute directly to the global challenges of food security and environmental sustainability. However, microbial inoculants have been used in agriculture for several decades with inconsistent efficacy. Key reasons of this inconsistent efficacy are linked to competition with indigenous soil microflora and inability to colonize plants. Endophytic microbes provide solutions to both of these issues which potentially make them better candidates for microbial inoculants. This article outlines the current advancements in endophytic research with special focus on endophytic bacilli. A better understanding of diverse mechanisms of disease control by bacilli is essential to achieve maximum biocontrol efficacy against multiple phytopathogens. Furthermore, we argue that integration of emerging technologies with strong theoretical frameworks have the potential to revolutionize biocontrol approaches based on endophytic microbes.

Fengycin produced by Bacillus subtilis XF-1 plays a major role in the biocontrol of Chinese cabbage clubroot via direct effect and defense stimulation.

Bacillus subtilis XF-1 is a well-investigated biocontrol agent against the biotrophic Plasmodiophora brassicae Woron., the causal agent of clubroot disease of cruciferous crops. The present study demonstrates that XF-1 could efficiently control clubroot disease via leaf spraying and provides an understanding of the biocontrol mechanisms. High-performance thin-layer chromatography (HTPLC) analysis indicated the presence of fengycin-type cyclopeptides in the supernatant. A ppsB deletion mutant of XF-1 resulted in no fengycin production, significantly reduced the lysis rate of testing spores in vitro and the primary infection rate of root hair in vivo, and decreased the protection value against clubroot disease under the greenhouse conditions. Confocal laser scanning microscopy proved that fengycin was not required for leaf internalization and root colonization. Moreover, the expression level of the ppsB gene in XF-1 was regulated by its cell density in root during interaction with P. brassicae. In addition, the ΔppsB mutant of XF-1 could not efficiently control disease because it led to a lower activation level of the jasmonic acid and salicylic acid signaling pathways in roots, which are necessary for the plant defense reaction upon pathogen invasion. Altogether, the present study provides a new understanding of specific cues in the interaction between B. subtilis and P. brassicae as well as insights into the application of B. subtilis in agriculture.

Structural mechanism of a dual-functional enzyme DgpA/B/C as both a C-glycoside cleaving enzyme and an O- to C-glycoside isomerase.

The C-glycosidic bond that connects the sugar moiety with aglycone is difficult to be broken or made due to its inert nature. The knowledge of C-glycoside breakdown and synthesis is very limited. Recently, the enzyme DgpA/B/C cascade from a human intestinal bacterium PUE was identified to specifically cleave the C-glycosidic bond of puerarin (daidzein-8-C-glucoside). Here we investigated how puerarin is recognized and oxidized by DgpA based on crystal structures of DgpA with or without substrate and biochemical characterization. More strikingly, we found that apart from being a C-glycoside cleaving enzyme, DgpA/B/C is capable of efficiently converting O- to C-glycoside showing the activity as a structure isomerase. A possible mechanistic model was proposed dependently of the simulated complex structure of DgpB/C with 3″-oxo-daidzin and structure-based mutagenesis. Our findings not only shed light on understanding the enzyme-mediated C-glycosidic bond breakage and formation, but also may help to facilitate stereospecific C-glycoside synthesis in pharmaceutical industry.

Weighted Gene Co-Expression Network Analysis to Explore Hub Genes of Resveratrol Biosynthesis in Exocarp and Mesocarp of 'Summer Black' Grape.

Resveratrol is a polyphenol compound beneficial to human health, and its main source is grapes. In the present study, the molecular regulation of resveratrol biosynthesis in developing grape berries was investigated using weighted gene co-expression network analysis (WGCNA). At the same time, the reason for the resveratrol content difference between grape exocarp (skin) and mesocarp (flesh) was explored. Hub genes (CHS, STS, F3'5'H, PAL, HCT) related to resveratrol biosynthesis were screened with Cytoscape software. The expression level of hub genes in the exocarp was significantly higher than that in the mesocarp, and the expressions of the hub genes and the content of resveratrol in exocarp peaked at the maturity stage. While the expression levels of PAL, CHS and STS in the mesocarp, reached the maximum at the maturity stage, and F3'5'H and HCT decreased. These hub genes likely play a key role in resveratrol biosynthesis. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis further indicated that resveratrol biosynthesis was related to flavonoid biosynthesis, phenylalanine metabolism, phenylpropanoid biosynthesis, and stilbene biosynthesis pathways. This study has theoretical significance for exploring genes related to resveratrol biosynthesis in the exocarp and mesocarp of grapes, and provides a theoretical basis for the subsequent function and regulatory mechanism of hub genes.