Summary
Abscisic acid (ABA) plays a crucial role in the adaptation of young seedlings to environmental stresses. However, the role of epigenetic components and core transcriptional machineries in the ...effect of ABA on seed germination and seedling growth remain unclear.
Here, we show that a histone 3 lysine 4 (H3K4) demethylase, JMJ17, regulates the expression of ABA‐responsive genes during seed germination and seedling growth. Using comparative interactomics, WRKY40, a central transcriptional repressor in ABA signaling, was shown to interact with JMJ17. WRKY40 facilitates the recruitment of JMJ17 to the ABI5 chromatin, which removes gene activation marks (H3K4me3) from the ABI5 chromatin, thereby repressing its expression.
Additionally, WRKY40 represses the transcriptional activation activity of HY5, which can activate ABI5 expression by directly binding to its promoter. An increase in ABA concentrations decreases the affinity of WRKY40 for the ABI5 promoter. Thus, WRKY40 and JMJ17 are released from the ABI5 chromatin, activating HY5. The accumulated ABI5 protein further shows heteromeric interaction with HY5, and thus synergistically activates its own expression.
Our findings reveal a novel transcriptional switch, composed of JMJ17–WRKY40 and HY5–ABI5 modules, which regulates the ABA response during seed germination and seedling development in Arabidopsis.
Under dehydration in plants, antagonistic activities of histone 3 lysine 4 (H3K4) methyl-transferase and histone demethylase maintain a dynamic and homeostatic state of gene expression by orientating ...transcriptional reprogramming toward growth or stress tolerance. However, the histone demethylase that specifically controls histone methylation homeostasis under dehydration stress remains unknown. Here, we document that a histone demethylase, JMJ17, belonging to the KDM5/JARID1 family, plays crucial roles in response to dehydration stress and abscisic acid (ABA) in Arabidopsis thaliana.
jmj17 loss-of-function mutants displayed dehydration stress tolerance and ABA hypersensitivity in terms of stomatal closure. JMJ17 specifically demethylated H3K4me1/2/3 via conserved iron-binding amino acids in vitro and in vivo. Moreover, H3K4 demethylase activity of JMJ17 was required for dehydration stress response.
Systematic combination of genome-wide chromatin immunoprecipitation coupled with massively parallel DNA sequencing (ChIP-seq) and RNA-sequencing (RNA-seq) analyses revealed that a loss-of-function mutation in JMJ17 caused an ectopic increase in genome-wide H3K4me3 levels and activated a plethora of dehydration stress-responsive genes. Importantly, JMJ17 bound directly to the chromatin of OPEN STOMATA 1 (OST1) and demethylated H3K4me3 for the regulation of OST1 mRNA abundance, thereby modulating the dehydration stress response.
Our results demonstrate a new function of a histone demethylase under dehydration stress in plants.
The insect gut microbiota has been shown to contribute to the host's digestion, detoxification, development, pathogen resistance, and physiology. However, there is poor information about the ranking ...of these roles. Most of these results were obtained with cultivable bacteria, whereas the bacterial physiology may be different between free-living and midgut-colonizing bacteria. In this study, we provided both proteomic and genomic evidence on the ranking of the roles of gut bacteria by investigating the anal droplets from a weevil, Cryptorhynchus lapathi.
The gut lumen and the anal droplets showed qualitatively and quantitatively different subsets of bacterial communities. The results of 16S rRNA sequencing showed that the gut lumen is dominated by Proteobacteria and Bacteroidetes, whereas the anal droplets are dominated by Proteobacteria. From the anal droplets, enzymes involved in 31 basic roles that belong to 7 super roles were identified by Q-TOF MS. The cooperation between the weevil and its gut bacteria was determined by reconstructing community pathway maps, which are defined in this study. A score was used to rank the gut bacterial roles. The results from the proteomic data indicate that the most dominant role of gut bacteria is amino acid biosynthesis, followed by protein digestion, energy metabolism, vitamin biosynthesis, lipid digestion, plant secondary metabolite (PSM) degradation, and carbohydrate digestion, while the order from the genomic data is amino acid biosynthesis, vitamin biosynthesis, lipid digestion, energy metabolism, protein digestion, PSM degradation, and carbohydrate digestion. The PCA results showed that the gut bacteria form functional groups from the point of view of either the basic role or super role, and the MFA results showed that there are functional variations among gut bacteria. In addition, the variations between the proteomic and genomic data, analyzed with the HMFA method from the point of view of either the bacterial community or individual bacterial species, are presented.
The most dominant role of gut bacteria is essential nutrient provisioning, followed by digestion and detoxification. The weevil plays a pioneering role in diet digestion and mainly digests macromolecules into smaller molecules which are then mainly digested by gut bacteria.
The lithium–sulfur (Li–S) battery is one of the most promising high-energy-density secondary battery systems. However, it suffers from issues arising from its extremely complicated ...“solid–liquid–solid” reaction routes. In recent years, enormous advances have been made in optimizing Li–S batteries via the rational design of compositions and architectures. Nevertheless, a comprehensive and in-depth understanding of the practical reaction mechanisms of Li–S systems and their effect on the electrochemical performance is still lacking. Very recently, several important in situ optical spectroscopic techniques, including Raman, infrared and ultraviolet-visible spectroscopies, have been developed to monitor the real-time variations of the battery states, and a bridge linking the macroscopic electrochemical performance and microscopic architectures of the components has been set up, thus playing a critical role in scientifically guiding further optimal design of Li–S batteries. In this tutorial review, we provide a systematic summary of the state-of-the-art innovations in the characterization and optimal design of Li–S batteries with the aid of these in situ optical spectroscopic techniques, to guide a beginner to construct in situ optical spectroscopy electrochemical cells, and develop strategies for preventing long-chain polysulfide formation, dissolution and migration, thus alleviating the shuttle effect in Li–S batteries and improving the cell performances significantly.
Fabricating a robust interfacial layer on the lithium metal anode to isolate it from liquid electrolyte is vital to restrain the rapid degradation of a lithium metal battery. Here, we report that the ...solution-processed metal chloride perovskite thin film can be coated onto the lithium metal surface as a robust interfacial layer to shield the lithium metal from liquid electrolyte. Via phase analysis and density functional theory calculations, we demonstrate that the perovskite layer can allow fast lithium ion shuttle under a low energy barrier of 0.45 eV without the collapse of framework. Such perovskite modification can realize stable cycling of LiCoO
|Li cells with an areal capacity of 2.8 mAh cm
using thin lithium metal foil (50 μm) and limited electrolyte (20 μl mAh
) for over 100 cycles at 0.5 C. The metal chloride perovskite protection strategy could open a promising avenue for advanced lithium metal batteries.
Brain tumors are dynamic complex ecosystems with multiple cell types. To model the brain tumor microenvironment in a reproducible and scalable system, we developed a rapid three-dimensional (3D) ...bioprinting method to construct clinically relevant biomimetic tissue models. In recurrent glioblastoma, macrophages/microglia prominently contribute to the tumor mass. To parse the function of macrophages in 3D, we compared the growth of glioblastoma stem cells (GSCs) alone or with astrocytes and neural precursor cells in a hyaluronic acid-rich hydrogel, with or without macrophage. Bioprinted constructs integrating macrophage recapitulate patient-derived transcriptional profiles predictive of patient survival, maintenance of stemness, invasion, and drug resistance. Whole-genome CRISPR screening with bioprinted complex systems identified unique molecular dependencies in GSCs, relative to sphere culture. Multicellular bioprinted models serve as a scalable and physiologic platform to interrogate drug sensitivity, cellular crosstalk, invasion, context-specific functional dependencies, as well as immunologic interactions in a species-matched neural environment.
Vaccine efforts to combat the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is responsible for the current coronavirus disease 2019 (COVID-19) pandemic, are focused on ...SARS-CoV-2 spike glycoprotein, the primary target for neutralizing antibodies. We performed cryo-election microscopy and site-specific glycan analysis of one of the leading subunit vaccine candidates from Novavax, which is based on a full-length spike protein formulated in polysorbate 80 detergent. Our studies reveal a stable prefusion conformation of the spike immunogen with slight differences in the S1 subunit compared with published spike ectodomain structures. We also observed interactions between the spike trimers, allowing formation of higher-order spike complexes. This study confirms the structural integrity of the full-length spike protein immunogen and provides a basis for interpreting immune responses to this multivalent nanoparticle immunogen.
Ni-doped spinel oxides NixCo1-xFe2O4 (x=0, 0.25, 0.5, 0.75) hollow nanospheres electrocatalysts are synthesized with a simple hydrothermal approach. Scanning electron microscopy (SEM) and X-ray ...diffraction (XRD) results reveal that the morphology, hollow and spinel structures of the cobalt ferrites remain unchanged with doping. The electrocatalytic activity of the Ni-doped CoFe2O4 with different doping contents has been studied and compared with the pure CoFe2O4 hollow nanospheres in alkaline solution by using rotating ring-disk electrode (RRDE) technique. For ORR, the Ni0.5Co0.5Fe2O4 (x=0.5) exhibits as the most active catalyst with the highest diffusion limited current density and more positive onset potential. Whereas, the Ni0.75Co0.25Fe2O4 (x=0.75) shows the best catalytic activity for OER with more negative onset potential (0.27V vs. Ag/AgCl) and maximum current density (36.0mA/cm2 at 1.0V). X-ray photoelectron spectra (XPS) measurements reveal that the oxygen vacancy on the oxide surfaces increases, while the cations occupied ratio on octahedral/tetrahedral sites in spinel structures decreases along with the increasing of the Ni doping content. Combining with the charge transfer resistance measured by electrochemical impedance spectroscopy (EIS), these three factors work synergistically on the catalytic activities of the Ni-doped CoFe2O4 hollow nanospheres.
Display omitted
•The poly(ionic liquid)/PVA hydrogel dressing does not release antibacterial agents.•This hydrogel dressing exhibits effective antibacterial ability and good mechanical property.•The ...mouse osteoblasts growth on the surface of hydrogel certified its excellent biocompatibility.•This hydrogel dressing can promote the reconstruction of intact epidermis.
Antibacterial wound dressings play an important role in wound healing and infection treatment. However, traditional antibacterial wound dressings uncontrollably release antibiotics or silver ions through passive diffusion. The overuse of antibiotics and silver ions may cause drug resistance, side effects, and argyrism, thereby hindering the healing process and creating other health hazards. To overcome these shortcomings, this paper reports an easy approach to synthesize non-releasing antimicrobial Poly(ionic liquid)/PVA hydrogel dressing with high-strength through chemical polymerization and physical cross-linking. The hydrogel dressing exhibited effective antibacterial ability against bacteria (E. coli, S. aureus and B. subtilis), fungus (C. albicans), and mold (Asp. niger, Asp. oryzae, and Rhizopus). Furthermore, in a murine model, the hydrogel dressing efficiently accelerated cutaneous wound healing. After 15 days of healing process, histological tests indicated that this hydrogel dressing can promote the reconstruction of intact epidermis faster than the control. Therefore, this Poly(ionic liquid)/PVA hydrogel has potential as an antibacterial wound-healing dressing.
Display omitted
•Geochemical baseline values of heavy metal in agricultural soil were evaluated.•The indexes of PI, EI and RI revealed that soil was moderately polluted wholly.•Apply geostatistical ...analysis, PMF and health risk model to obtain sources.•There were no significant carcinogenic and non-carcinogenic risk effects.•Agriculture, industry and traffic were the main and priority pollution sources.
To determine the heavy metal contamination of agricultural soil in the Hexi Corridor, 376 soil samples were collected and analyzed for their heavy metal content. The geochemical baseline value (GBV), single-factor pollution index (PI), ecological risk of a single heavy metal, and comprehensive ecological risk index (RI) were used to assess the degree of pollution. Geostatistical analysis, positive matrix factorization (PMF), and a health risk assessment model were used to determine the primary sources of pollution and priority sources. Although the mean Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, and Pb concentrations (2717, 62.85, 48.23, 511.6, 24827, 51.29, 26.47, 53.98, 12.39, 16.85 mg•kg−1 in the west, 3046, 72.15, 59.32, 598.1, 27614, 54.57, 29.55, 59.47, 13.63, 20.74 mg•kg−1 in the center, and 2558, 61.02, 39.67, 466.7, 22575, 39.94, 26.06, 54.81, 11.86, 20.38 mg•kg−1 in the east, respectively) did not exceed the national critical values, approximately 1% of the west As samples did exceed their critical values. The mean concentrations of the heavy metals were less than their corresponding GBVs. The PI and RI revealed that the agricultural soil was moderately polluted, at low ecological risk, and the least polluted in the center. Based on PMF, Factor 1 represented metal processing; Factor 2 represented the mixed sources of electroplating and smelting in the west and center, and the mixed sources of mining and agricultural activities in the east; Factor 3 was ascribed to agriculture; and Factor 4 was the mixed sources of atmospheric deposition and traffic emission. The main pollution source, Factor 4 in the west and east and Factor 2 in the center, had the highest percent proportion of total metals and priority pollution sources, thus contributing the most to the carcinogenic (Factor 2 in the west and Factor 3 in the center and east) and non-carcinogenic risks (Factor 2 for adults and Factor 1 for children in the west and Factor 3 in the center and east), respectively.
PDF
