Architecture of ß-lactoglobulin coating modulates bioinspired alginate dialdehyde-gelatine/polydopamine scaffolds for subchondral bone regeneration.

In this study, we developed polydopamine (PDA)-functionalized alginate dialdehyde-gelatine (ADA-GEL) scaffolds for subchondral bone regeneration. These polymeric scaffolds were then coated with ß-Lactoglobulin (ß-LG) at concentrations of 1 mg/ml and 2 mg/ml. Morphological analysis indicated a homogeneous coating of the ß-LG layer on the surface of network-like scaffolds. The ß-LG-coated scaffolds exhibited improved swelling capacity as a function of the ß-LG concentration. Compared to ADA-GEL/PDA scaffolds, the ß-LG-coated scaffolds demonstrated delayed degradation and enhanced biomineralization. Here, a lower concentration of ß-LG showed long-lasting stability and superior biomimetic hydroxyapatite mineralization. According to the theoretical findings, the single-state, representing the low concentration of ß-LG, exhibited a homogeneous distribution on the surface of the PDA, while the dimer-state (high concentration) displayed a high likelihood of uncontrolled interactions. ß-LG-coated ADA-GEL/PDA scaffolds with a lower concentration of ß-LG provided a biocompatible substrate that supported adhesion, proliferation, and alkaline phosphatase (ALP) secretion of sheep bone marrow mesenchymal stem cells, as well as increased expression of osteopontin (SPP1) and collagen type 1 (COL1A1) in human osteoblasts. These findings indicate the potential of protein-coated scaffolds for subchondral bone tissue regeneration. STATEMENT OF SIGNIFICANCE: This study addresses a crucial aspect of osteochondral defect repair, emphasizing the pivotal role of subchondral bone regeneration. The development of polydopamine-functionalized alginate dialdehyde-gelatine (ADA-GEL) scaffolds, coated with ß-Lactoglobulin (ß-LG), represents a novel approach to potentially enhance subchondral bone repair. ß-LG, a milk protein rich in essential amino acids and bioactive peptides, is investigated for its potential to promote subchondral bone regeneration. This research explores computationally and experimentally the influence of protein concentration on the ordered or irregular deposition, unravelling the interplay between coating structure, scaffold properties, and in-vitro performance. This work contributes to advancing ordered protein coating strategies for subchondral bone regeneration, providing a biocompatible solution with potential implications for supporting subsequent cartilage repair.

The NAC gene family in the halophyte Limonium bicolor: Identification, expression analysis, and regulation of abiotic stress tolerance.

NAC transcription factors regulate plant growth, development, and stress responses. However, the number, types, and biological functions of Limonium bicolor LbNAC genes have remained elusive. L. bicolor secretes excessive salt ions through salt glands on its stems and leaves to reduce salt-induced damage. Here, we identified 63 NAC members (LbNAC1-63) in L. bicolor, which were unevenly distributed across eight chromosomes. Cis-elements in the LbNAC promoters were related to growth and development, stress responses, and phytohormone responses. We observed strong colinearity between LbNACs and GmNACs from soybean (Glycine max). Thus, LbNAC genes may share similar functions with GmNAC genes. Expression analysis indicated that 16 LbNAC genes are highly expressed in roots, stems, leaves, and flowers, whereas 17 LbNAC genes were highly expressed throughout salt gland development, suggesting that they may regulate this developmental stage. Silencing LbNAC54 in L. bicolor decreased salt gland density, salt secretion from leaves, and overall salt tolerance. In agreement, genes related to salt gland development were significantly downregulated in LbNAC54-silenced lines. Our findings shed light on LbNAC genes and help elucidate salt gland development and salt secretion in L. bicolor. Our data also provide insight into NAC functions in halophytes.

The Impact of Family Dynamics, Lifestyle, and Food Intolerance on ADHD in Children.

Objective: This study analyzes the relationship between ADHD, family relationships, lifestyle, and food intolerance. Methods: This study consisted of 240 children who received treatment at the researchers' hospital from January 2022 to November 2022. Out of these, 120 children belonged to the ADHD group, while the remaining 120 children were part of the healthy control group. The researchers compared these two groups of children on factors such as family relationships, lifestyle, and food intolerance. Results: The general data of the two groups were not statistically significant but comparable (P > .05); family relationships, lifestyle, and food intolerance all affected children with ADHD (P < .01). Conclusion: In the investigation of children with ADHD compared to healthy children, the influence of family relationships, lifestyle, and food intolerance can all cause ADHD.

Preliminary identification and semi-quantitative characterization of a multi-faceted high-stability alginate lyase from marine microbe Seonamhaeicola algicola with anti-biofilm effect on Pseudomonas aeruginosa.

Alginate lyases with unique characteristics for degrading alginate into size-defined oligosaccharide fractions, were considered as the potential agents for disrupting Pseudomonas aeruginosa biofilms. In our study, a novel endolytic PL-7 alginate lyase, named AlyG2, was cloned and expressed through Escherichia coli. This enzyme exhibited excellent properties: it maintained more than 85% activity at low temperatures of 4 °C and high temperatures of 70 °C. After 1 h of incubation at 4 °C, it still retained over 95% activity, demonstrating the ability to withstand low temperature. The acid-base and salt tolerance properties shown it preserves more than 50% activity in the pH range of 5.0 to 11.0 and in a high salt environment at 3000 mM NacCl, indicating its high stability in several aspects. More importantly, AlyG2 in our research was revealed to be effective at removing mature biofilms and inhibiting biofilm formation produced by Pseudomonas aeruginosa, and the inhibition and disruption rates were 47.25 ± 4.52% and 26.5 ± 6.72%, respectively. Additionally, the enzyme AlyG2 promoted biofilm disruption in combination with antibiotics, particularly manifesting the synergistic effect with erythromycin (FIC=0.5). In all, these results offered that AlyG2 with unique characteristics may be an effective technique for the clearance or disruption of biofilm produced by P. aeruginosa.

Preparation of isoquercitrin and rhamnose from readily accessible rutin by a highly specific recombinant α-L-rhamnosidase (r-Rha1).

Isoquercitrin has superior in vivo bioactivities with respect to its primary glycoside rutin. Its conventional preparation was ineffective, with large chemical consumption and many by-products. Rhamnose, a high value-added monosaccharide, is usually separated from acid hydrolytes of rutin. This study aimed to establish a novel enzymatic hydrolysis-based approach for their preparation. α-L-rhamnosidase was expressed in Pichia pastoris GS115 and applied to enzymolysis of rutin. Then, one-factor-at-a-time optimisation of hydrolysis conditions was performed. Two compounds were produced in 0.02 M HAc-NaAc buffer (pH4.50) containing α-L-rhamnosidase/rutin (1:4, w/w) at 60 °C. Consequently, 20.0 g/L rutin was completely hydrolysed in 2 hrs, and isoquercitrin was obtained after purification by HPD-100 resin. Additionally, rhamnose was enriched by decolorisation and crystallisation. MD simulation analysis suggested that rutin was catalysed on the hydrophobic surface of r-Rha1 with van-der-Waals force being main driving force. This strategy is an efficient approach for preparation of isoquercitrin and rhamnose.

Optimization Strategy of College Students' Education Management Based on Smart Cloud Platform Teaching.

With the passage of time and social changes, the form of education is also changing step by step. In just a few decades, information technology has developed by leaps and bounds, and digital education has not yet been widely promoted. Intelligent education cloud platforms based on big data, Internet of things, cloud computing, and artificial intelligence have begun to emerge. The research on the "smart campus" cloud platform is conducive to improving the utilization rate of existing hardware equipment in colleges and universities and is conducive in improving the level of teaching software deployment. At the same time, this research also provides a new idea for the research in the field of cloud security. While cloud computing brings convenience to teaching work, it also brings new problems to system security. At present, virtualization technology is still in the ascendant stage in the construction of "smart campus" in colleges and universities and is gradually applied to cloud computing service products. At present, there are many cases about the construction of teaching resource platform, but most of them are modified from the early resource management system, which has strong coupling of single system, insufficient functions of collecting, processing, searching, sharing, and reusing resources, and weak application support ability for related business systems. Under this social background, this paper studies the teaching process management system for intelligent classroom.

Spatial transcriptomics: recent developments and insights in respiratory research.

The respiratory system's complex cellular heterogeneity presents unique challenges to researchers in this field. Although bulk RNA sequencing and single-cell RNA sequencing (scRNA-seq) have provided insights into cell types and heterogeneity in the respiratory system, the relevant specific spatial localization and cellular interactions have not been clearly elucidated. Spatial transcriptomics (ST) has filled this gap and has been widely used in respiratory studies. This review focuses on the latest iterative technology of ST in recent years, summarizing how ST can be applied to the physiological and pathological processes of the respiratory system, with emphasis on the lungs. Finally, the current challenges and potential development directions are proposed, including high-throughput full-length transcriptome, integration of multi-omics, temporal and spatial omics, bioinformatics analysis, etc. These viewpoints are expected to advance the study of systematic mechanisms, including respiratory studies.

Human induced pluripotent stem cell (iPSC) line (HEBHMUi014-A) derived from a patient with Alzheimer's disease.

The ε4 allele of the lipoprotein E gene (APOE4) is the strongest genetic risk factor associated with sporadic Alzheimer's disease (sAD). While the neuronal cell type-specific function of APOE4 in connection with AD pathology remains understudied. Therefore, we generated an induced pluripotent stem cells (iPSCs) line from a 77-year-old female donor with ApoE4 genetic background. We reprogrammed peripheral blood mononuclear cells (PBMCs) with non-integrative Sendai viral vectors containing reprogramming factors. Established iPSCs showed the capability of pluripotency, three-germ differentiation in vitro with normal karyotype. Hence, the generated iPSC could be a powerful tool to conduct further studies of AD mechanisms.

Amplectobeluid Radiodont Guanshancaris gen. nov. from the Lower Cambrian (Stage 4) Guanshan Lagerstätte of South China: Biostratigraphic and Paleobiogeographic Implications.

Radiodonta, an extinct stem-euarthropod group, has been considered as the largest predator of Cambrian marine ecosystems. As one of the radiodont-bearing Konservat-Lagerstätten, the Guanshan biota (South China, Cambrian Stage 4) has yielded a diverse assemblage of soft-bodied and biomineralized taxa that are exclusive to this exceptional deposit. "Anomalocaris" kunmingensis, the most abundant radiodont in the Guanshan biota, was originally assigned to Anomalocaris within the Anomalocarididae. Despite this taxon being formally assigned to the family Amplectobeluidae more recently, its generic assignment remains uncertain. Here, we present new materials of "Anomalocaris" kunmingensis from the Guanshan biota, and reveal that the frontal appendages possess two enlarged endites; all endites bear one posterior auxiliary spine and up to four anterior auxiliary spines; three robust dorsal spines and one terminal spine protrude from the distal part. These new observations, allied with anatomical features illustrated by previous studies, allow us to assign this taxon to a new genus, Guanshancaris gen. nov. Brachiopod shell bearing embayed injury and incomplete trilobites, associated with frontal appendages in our specimens, to some extent confirm Guanshancaris as a possible durophagous predator. The distribution of amplectobeluids demonstrates that this group is restricted to Cambrian Stage 3 to Drumian, and occurs across South China and Laurentia within the tropics/subtropics belt. Moreover, the amount and abundance of amplectobeluids evidently decreases after the Early-Middle Cambrian boundary, which indicates its possible preference for shallow water, referring to its paleoenvironmental distribution and may be influenced by geochemical, tectonic, and climatic variation.

Insights into the Influence of Signal Peptide on the Enzymatic Properties of Alginate Lyase AlyI1 with Removal Effect on Pseudomonas aeruginosa Biofilm.

Most reports on signal peptides focus on their ability to affect the normal folding of proteins, thereby affecting their secreted expression, while few studies on its effects on enzymatic properties were published. Therefore, biochemical characterization and comparison of alginate lyase rALYI1/rALYI1-1 (rALYI1: without signal peptides; rALYI1-1:with signal peptides) were conducted in our study, and the results showed that the signal peptide affected the biochemical properties, especially in temperature and pH. rALYI1 (32.15 kDa) belonging to polysaccharide lyase family 7 was cloned from sea-cucumber-gut bacterium Tamlana sp. I1. The optimum temperature of both rALYI1 and rALYI1-1 was 40 °C, but the former had a wider optimum temperature range and better thermal stability. The optimum pH of rALYI1 and rALYI1-1 were 7.6 and 8.6, respectively. The former was more stable and acid resistant. Noticeably, rALYI1 was a salt-activated enzyme and displayed remarkable salt tolerance. Alginate, an essential polysaccharide in algae and Pseudomonas aeruginosa biofilms, is composed of α-L-guluronate and ß-D-mannuronate. It is also found in our study that rALYI1 is also effective in removing mature biofilms compared with controls. In conclusion, the signal peptide affects several biochemical properties of the enzyme, and alginate lyase rALYI1 may be an effective method for inhibiting biofilm formation of Pseudomonas aeruginosa.

The Experience of Pregnant Women in the Health Management Model of Internet-Based Centering Pregnancy: A Qualitative Study.

Background: CenteringPregnancy Care is a promising group prenatal care innovation that combines assessment, education, and peer support. In China, it is not clear how best to integrate the CenteringPregnancy Care into existing maternal health care models. This qualitative study aimed to explore Chinese pregnant women's experience in the Internet-based CenteringPregnancy management model. Methods: The Internet-based CenteringPregnancy was applied in a tertiary hospital between 2018 and 2019 in Wuhan, Hubei Province. Through purposive sampling, a total of 9 pregnant women who had experienced Internet-based CenteringPregnancy were recruited. A semi-structured interview was used to collect qualitative data, and Colaizzi's 7-step method of phenomenological data analysis was used to analyze the collected data. Results: Three themes were extracted from the participants' interviews, including: 1) empowerment; 2) psychological and social support; 3) challenges of the Internet-based CenteringPregnancy. The Internet-based CenteringPregnancy management model retained advantages of CenteringPregnancy, emphasizing the pregnant woman as the subject of health care and promoting them to participate in health care. Participants believed that they could exchange pregnancy knowledge, help each other, and improve mood both timely and efficiently from the new model. However, it was found that there were challenges in seminar time arrangement, topic selection, and discussion management. Conclusion: The Internet-based CenteringPregnancy management model positively affected pregnant women's empowerment, psychological, and social support. It is recommended to improve the seminar's design in future studies.

Neuropeptide Y regulates cholesterol uptake and efflux in macrophages and promotes foam cell formation.

The dysregulation of lipid metabolic pathways (cholesterol uptake and efflux) in macrophages results in the formation of lipid-dense macrophages, named foam cells, that participate in plaque formation. NPY binding to NPY receptors in macrophages can modulate cell functions and affect the process of atherosclerotic plaques. The present study aimed to determine whether NPY affects the formation of macrophage-derived foam cells and its underlying mechanisms in macrophages. THP-1-derived macrophages were incubated with oxidized low-density lipoprotein (ox-LDL) and treated with different concentrations of NPY. We analysed the relative levels of proteins related to cholesterol uptake and efflux. We found that NPY effectively increased cholesterol uptake and intracellular cholesterol content via the Y1 and Y5 receptors, and this effect was blocked by Y1 and Y5 antagonists. Mechanistically, NPY enhanced the expression of SRA and CD36 via the PKC/PPARγ pathways, promoting macrophage cholesterol uptake. Moreover, NPY significantly decreased cholesterol efflux to the extracellular cholesterol acceptors ApoA1 and HDL in macrophages. NPY mediated decreases in ABCA1, ABCG1 and SR-BI expression through the inhibition of the JAK/STAT3 pathways. Our results suggest that NPY binding to the Y1 and Y5 receptors enhances foam cell formation by regulating cholesterol uptake and efflux in macrophages.

Efficacy of Shexiang Tongxin Dropping Pills in a Swine Model of Coronary Slow Flow.

Objective: Preliminary clinical studies have confirmed that Shexiang Tongxin dropping pills (STDPs) could improve angina pectoris and attenuate vascular endothelial dysfunction in patients with slow coronary flow, but the underlying mechanism is not fully unclear. We aimed to investigate the impact of STDP in a swine model of coronary slow flow (SF) and related mechanisms. Methods: SF was induced by coronary injection of 40 µ m microspheres, and pigs were randomly divided into the SF group and SF plus STDP group. Pigs in the STDP group received sublingual STDP for 10 min, followed by 1 g STDP oral administration daily for 6 days. Coronary angiography was performed, the TIMI frame count (TFC) was determined, and hemodynamic measurements were performed before, at 30 min, and 7 days post-SF. Serum levels of total NO, NOS, ET-1, C-TNI, and BNP were measured. Myocardial expressions of TNF and IL-6, eNOS, VEGF, CD31, and α-SMA were analyzed by immunohistochemistry and Western blotting. Results: Compared to the SF group, LVEF and TFC were significantly improved at 7 days post-SF in the STDP group. The serum ET-1 level was significantly reduced at 7 days, and NO and NOS levels were significantly higher in the STDP group. Seven days post-SF, myocardial TNF and IL-6 expressions were significantly downregulated, while the expressions of eNOS and VEGF, CD31, and ɑ-SMA were significantly upregulated in the STDP group. Conclusion: Our results showed that STDP improved cardiac function and coronary flow, possibly through reducing inflammatory responses and upregulating myocardial eNOS and VEGF, CD31, and the ɑ-SMA expression.

Heterologous expression of a Fraxinus velutina SnRK2 gene in Arabidopsis increases salt tolerance by modifying root development and ion homeostasis.

KEY MESSAGE: FvSnRK2182 is involved in regulating the growth and stress response. SnRK2 family members are positive regulators of downstream signals in the abscisic acid (ABA) signaling pathway, playing key roles in the plant responses to abiotic stresses. Fraxinus velutina Torr. is a candidate phytoremediator of saline-alkali areas, and is a valuable research subject because of its adaptability in saline soil. We identified a SnRK2 gene in F. velutina (named FvSnRK2182), which was significantly upregulated under salt stress. A bioinformatics analysis showed that FvSnRK2182 has a Ser/Thr kinase domain typical of the SnRK2 subfamily. Compared with wild-type (WT) Arabidopsis, its heterologous expression in Arabidopsis resulted in higher auxin content during seed germination and seedling growth, leading to longer primary roots and more lateral roots. The transgenic lines were better able to tolerate treatments with NaCl (100 mM) and/or ABA (0.2 and 0.5 µM), producing a greater biomass than the WT plants. Under NaCl treatment, the shoots of the transgenic lines had lower Na+ contents and higher K+ contents than the WT plants, and the genes encoding the ion transport-related proteins SOS1, HKT1, NHX1, and AKT1 were significantly upregulated. In addition, the expression of the genes functioning downstream of SnRK2 in the ABA signaling pathway (Rboh, AREB4, ABF2, and ABF3) were significantly upregulated in transgenic lines under NaCl stress. These results showed that expressing FvSnRK2182 in Arabidopsis significantly increased their resistance to ABA and salt stress by regulating root development and maintaining ion homeostasis, which suggests that FvSnRK2182 may be involved in regulating the growth and stress response of F. velutina.

Microencapsulating Alginate-Based Polymers for Probiotics Delivery Systems and Their Application.

Probiotics exhibit many health benefits and a great potential for broad applications in pharmaceutical fields, such as prevention and treatment of gastrointestinal tract diseases (irritable bowel syndrome), prevention and therapy of allergies, certain anticancer effects, and immunomodulation. However, their applications are limited by the low viability and metabolic activity of the probiotics during processing, storage, and delivery in the digestive tract. To overcome the mentioned limitations, probiotic delivery systems have attracted much attention. This review focuses on alginate as a preferred polymer and presents recent advances in alginate-based polymers for probiotic delivery systems. We highlight several alginate-based delivery systems containing various types of probiotics and the physical and chemical modifications with chitosan, cellulose, starch, protein, fish gel, and many other materials to enhance their performance, of which the viability and protective mechanisms are discussed. Withal, various challenges in alginate-based polymers for probiotics delivery systems are traced out, and future directions, specifically on the use of nanomaterials as well as prebiotics, are delineated to further facilitate subsequent researchers in selecting more favorable materials and technology for probiotic delivery.

Jeotgalibacillus aurantiacus sp. nov., a novel orange-pigmented species with a carotenoid biosynthetic gene cluster, isolated from wetland soil.

A Gram-stain-positive, orange-pigmented, rod-shaped and flagellated bacterial strain T12T was isolated from wetland soil in Kunyu Mountain Wetland in Yantai, China. The strain was able to grow at 15-40 °C (optimum 37 °C), at 0.0-9.0% NaCl (optimum 2%, w/v) and at pH 5.5-9.0 (optimum 8.5). A phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain T12T is a member of the family Planococcaceae, sharing 97.6% and 97.1% sequence similarity with the type strains of Jeotgalibacillus salarius and Jeotgalibacillus marinus, respectively. Genome-based analyses revealed a genome size of 3,506,682 bp and a DNA G + C content of 43.7%. Besides, the genome sequence led to 55.0-74.6% average amino acid identity values and 67.8-74.7% average nucleotide identity values between strain T12T and the current closest relatives. Digital DNA-DNA hybridization of strain T12T with the type strains of Jeotgalibacillus proteolyticus and J. marinus demonstrated 19.0% and 20.3% relatedness, respectively. The chemotaxonomic analysis showed that the sole quinone was MK-7. The predominant cellular fatty acids were iso-C15:0, anteiso-C15:0, C16:1ω7c alcohol and iso-C14:0. The polar lipids consisted of an unidentified aminolipid, phosphatidylglycerol, diphosphatidylglycerol and two unidentified phospholipids. Based on the polyphasic characterization, strain T12T is considered to represent a novel species, for which the name Jeotgalibacillus aurantiacus sp. nov. is proposed. The type strain is T12T (= KCTC 43296 T = MCCC 1K07171T).

Feasibility Study on the Steel-Plastic Geogrid Instead of Wire Mesh for Bolt Mesh Supporting.

Wire mesh is a common material for bolt mesh supporting structures, but its application in engineering has revealed many defects. At the same time, with the development of new materials for civil engineering, the new material mesh performance and cost show outstanding advantages over wire mesh. In this paper, the feasibility of replacing wire mesh with steel-plastic geogrid as an alternative material is carefully studied through indoor tests and field applications. The following conclusions were drawn from a comparative analysis with wire mesh, mainly in terms of mechanical properties, engineering characteristics, and construction techniques: (1) in terms of mesh wire strength, wire mesh is slightly better than steel-plastic geogrid, but in the case of similar tensile strength, the amount of steel used per unit length of steel geogrid bars is only 36.75% of that of steel-plastic geogrid, while the tensile strength of the high-strength steel wire attached to the steel-plastic geogrid belt is about 3.3 times that of steel bars; (2) in terms of junction peel strength, both values are similar, with the injection-moulded junction being 1154.56-1224.38 N and the welded junction of 4 mm mesh being 988.35 N; (3) in terms of the strength of the mesh, steel-plastic geogrid is better than wire mesh, and with the same mesh wire strength, the bearing capacity of steel-plastic geogrid is increased by about 63.17% and the contribution of the mesh wire bearing capacity is increased by 83.66%, with the damage mainly being in the form of wire breakage in the ribbon causing ribbon failure, leading to further damage to the mesh; (4) in terms of the engineering application of steel-plastic geogrid compared to wire mesh, the utilization rate of mesh increases by about 24.99%, the construction efficiency increases by about 14.10%, and the economic benefit increases by about 45.31%. In practical application, the steel-plastic geogrid has good adhesion with surrounding rock and strong corrosion resistance. According to the above research analysis, the steel-plastic geogrid is feasible to replace the wire mesh for bolt mesh supporting.

Melatonin increases growth and salt tolerance of Limonium bicolor by improving photosynthetic and antioxidant capacity.

BACKGROUND: Soil salinization is becoming an increasingly serious problem worldwide, resulting in cultivated land loss and desertification, as well as having a serious impact on agriculture and the economy. The indoleamine melatonin (N-acetyl-5-methoxytryptamine) has a wide array of biological roles in plants, including acting as an auxin analog and an antioxidant. Previous studies have shown that exogenous melatonin application alleviates the salt-induced growth inhibition in non-halophyte plants; however, to our knowledge, melatonin effects have not been examined on halophytes, and it is unclear whether melatonin provides similar protection to salt-exposed halophytic plants. RESULTS: We exposed the halophyte Limonium bicolor to salt stress (300 mM) and concomitantly treated the plants with 5 µM melatonin to examine the effect of melatonin on salt tolerance. Exogenous melatonin treatment promoted the growth of L. bicolor under salt stress, as reflected by increasing its fresh weight and leaf area. This increased growth was caused by an increase in net photosynthetic rate and water use efficiency. Treatment of salt-stressed L. bicolor seedlings with 5 µM melatonin also enhanced the activities of antioxidants (superoxide dismutase [SOD], peroxidase [POD], catalase [CAT], and ascorbate peroxidase [APX]), while significantly decreasing the contents of hydrogen peroxide (H2O2), superoxide anion (O2•-), and malondialdehyde (MDA). To screen for L. bicolor genes involved in the above physiological processes, high-throughput RNA sequencing was conducted. A gene ontology enrichment analysis indicated that genes related to photosynthesis, reactive oxygen species scavenging, the auxin-dependent signaling pathway and mitogen-activated protein kinase (MAPK) were highly expressed under melatonin treatment. These data indicated that melatonin improved photosynthesis, decreased reactive oxygen species (ROS) and activated MAPK-mediated antioxidant responses, triggering a downstream MAPK cascade that upregulated the expression of antioxidant-related genes. Thus, melatonin improves the salt tolerance of L. bicolor by increasing photosynthesis and improving cellular redox homeostasis under salt stress. CONCLUSIONS: Our results showed that melatonin can upregulate the expression of genes related to photosynthesis, reactive oxygen species scavenging and mitogen-activated protein kinase (MAPK) of L. bicolor under salt stress, which can improve photosynthesis and antioxidant enzyme activities. Thus melatonin can promote the growth of the species and maintain the homeostasis of reactive oxygen species to alleviate salt stress.

Integrative transcriptome and proteome analyses provide deep insights into the molecular mechanism of salt tolerance in Limonium bicolor.

KEY MESSAGE: Integrative transcriptome and proteome analyses revealed many candidate members that may involve in salt secretion from salt glands in Limonium bicolor. Limonium bicolor, a typical recretohalophyte, protects itself from salt damage by excreting excess salt out of its cells through salt glands. Here, to provide an overview of the salt-tolerance mechanism of L. bicolor, we conducted integrative transcriptome and proteome analyses of this species under salt treatment. We identified numerous differentially expressed transcripts and proteins that may be related to the salt-tolerance mechanism of L. bicolor. By measuring the Na+ secretion rate, were found that this cation secretion rate of a single salt gland was significantly increased after high salinity treatment compared with that in control and then reached the maximum in a short time. Interestingly, transcripts and proteins involved in transmembrane transport of ions were differentially expressed in response to high salinity treatment, suggesting a number of genes and proteins they may play important roles in the salt-stress response. Correlation between differentially expressed transcript and protein profiles revealed several transcripts and proteins that may be responsible for salt tolerance, such as cellulose synthases and annexins. Our findings uncovered many candidate transcripts and proteins in response to the salt tolerance of L. bicolor, providing deep insights into the molecular mechanisms of this important process in recretohalophytes.

Williamsia soli sp. nov., an actinobacterium isolated from soil at a thermal power plant in Yantai, China.

Strain C17T, a novel strain belonging to the phylum Actinobacteria, was isolated from a thermal power plant in Yantai, Shandong Province, China. Cells of strain C17T were Gram stain positive, aerobic, pink, non-motile and round with neat edges, showing optimum growth at 28 °C. Phylogenetically, strain C17T was a member of the class Actinobacteria, order Mycobacteriales, family Gordoniaceae. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that the related strains were Williamsia faeni JCM 17784 T and Williamsia limnetica KCTC 19981 T with pairwise sequence similarity of 98.5% for both strains. According to the draft genome sequence, the DNA G + C content was 64.7%. The average amino acid identity (AAI), average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between genome sequences of strain C17T and the closest type strain W. faeni JCM 17784 T were 77.5, 77.9, and 20.7%, respectively. Predominant fatty acids were C16:0 (31.7%) and C18:1ω9c (26.8%). The major menaquinone was MK-9. The diagnostic phospholipids were phosphatidylethanolamine (PE), diphosphatidylglycerol (DPG), and phosphatidylinositol (PI). Therefore, the combined phenotypic, chemotaxonomic and phylogenetic data indicated that strain C17T was considered to represent a novel species of the genus Williamsia. Williamsia soli sp. nov. was proposed for strain C17T (= KCTC 49567 T = MCCC 1K04355T).