AtSNU13 modulates pre-mRNA splicing of RBOHD and ALD1 to regulate plant immunity.

Pre-mRNA splicing is a significant step for post-transcriptional modifications and functions in a wide range of physiological processes in plants. Human NHP2L binds to U4 snRNA during spliceosome assembly; it is involved in RNA splicing and mediates the development of human tumors. However, no ortholog has yet been identified in plants. Therefore, we report At4g12600 encoding the ortholog NHP2L protein, and AtSNU13 associates with the component of the spliceosome complex; the atsnu13 mutant showed compromised resistance in disease resistance, indicating that AtSNU13 is a positive regulator of plant immunity. Compared to wild-type plants, the atsnu13 mutation resulted in altered splicing patterns for defense-related genes and decreased expression of defense-related genes, such as RBOHD and ALD1. Further investigation shows that AtSNU13 promotes the interaction between U4/U6.U5 tri-snRNP-specific 27 K and the motif in target mRNAs to regulate the RNA splicing. Our study highlights the role of AtSNU13 in regulating plant immunity by affecting the pre-mRNA splicing of defense-related genes.

Glutathione and neodiosmin feedback sustain plant immunity.

Plants have evolved a two-layer immune system comprising pattern-triggered immunity (PTI) and effector-triggered immunity (ETI) that is activated in response to pathogen invasion. Microbial patterns and pathogen effectors can be recognized by surface-localized pattern-recognition receptors (PRRs) and intracellularly localized nucleotide-binding leucine-rich repeat receptors (NLRs) to trigger PTI and ETI responses, respectively. At present, the metabolites activated by PTI and ETI and their roles and signalling pathways in plant immunity are not well understood. In this study, metabolomic analysis showed that ETI and PTI induced various flavonoids and amino acids and their derivatives in plants. Interestingly, both glutathione and neodiosmin content were specifically up-regulated by ETI and PTI, respectively, which significantly enhanced plant immunity. Further studies showed that glutathione and neodiosmin failed to induce a plant immune response in which PRRs/co-receptors were mutated. In addition, glutathione-reduced mutant gsh1 analysis showed that GSH1 is also required for PTI and ETI. Finally, we propose a model in which glutathione and neodiosmin are considered signature metabolites induced in the process of ETI and PTI activation in plants and further continuous enhancement of plant immunity in which PRRs/co-receptors are needed. This model is beneficial for an in-depth understanding of the closed-loop mode of the positive feedback regulation of PTI and ETI signals at the metabolic level.

Microbial volatile organic compounds 2-heptanol and acetoin control Fusarium crown and root rot of tomato.

Some microbial volatile organic compounds (mVOCs) can act as antagonistic weapons against plant pathogens, but little information is available on the contribution of individual mVOC to biocontrol and how they interact with plant pathogens. In this study, the Bacillus subtilis strain N-18 isolated from the rhizosphere of healthy plants grown in areas where Fusarium crown and root rot (FCRR) of tomato occurs could reduce the 30% of the incidence of FCRR. Moreover, the volatile organic compounds (VOCs) produced by N-18 had inhibitory effects on Fusarium oxysporum f. sp. radicis-lycopersici (FORL). The identification of VOCs of N-18 was analyzed by the solid-phase microextraction coupled to gas chromatography-mass spectrometry. Meanwhile, we conducted sensitivity tests with these potential active ingredients and found that the volatile substances acetoin and 2-heptanol can reduce the 41.33% and 35% of the incidence of FCRR in tomato plants. In addition, the potential target protein of acetoin, found in the cheminformatics and bioinformatics database, was F. oxysporum of hypothetical protein AU210_012600 (FUSOX). Molecular docking results further predicted that acetoin interacts with FUSOX protein. These results reveal the VOCs of N-18 and their active ingredients in response to FORL and provide a basis for further research on regulating and controlling FCRR.

Characterization of the Interaction between Gallic Acid and Lysozyme by Molecular Dynamics Simulation and Optical Spectroscopy.

The binding interaction between gallic acid (GA) and lysozyme (LYS) was investigated and compared by molecular dynamics (MD) simulation and spectral techniques. The results from spectroscopy indicate that GA binds to LYS to generate a static complex. The binding constants and thermodynamic parameters were calculated. MD simulation revealed that the main driving forces for GA binding to LYS are hydrogen bonding and hydrophobic interactions. The root-mean-square deviation verified that GA and LYS bind to form a stable complex, while the root-mean-square fluctuation results showed that the stability of the GA-LYS complex at 298 K was higher than that at 310 K. The calculated free binding energies from the molecular mechanics/Poisson-Boltzmann surface area method showed that van der Waals forces and electrostatic interactions are the predominant intermolecular forces. The MD simulation was consistent with the spectral experiments. This study provides a reference for future study of the pharmacological mechanism of GA.

[Investigation of properties of the resveratrol-beta-cyclodextrin inclusion complex by drug-protein interaction spectra and molecular modeling].

The supramolecular inclusion properties of beta-cyclodextrin (beta-CD) and resveratrol (Res) were investigated using drug-protein interaction spectroscopy method. The differences between the results of interaction spectroscopy method and the results of classical method were compared. The total energy of the stable inclusion of cyclodextrin-resveratrol was calculated by Gaussian theory calculation. The stable inclusions in the process of interaction between resveratrol/inclusion complex and bovine lactgoferrin (BLF) were studied by molecular modeling. The results showed that the interaction spectroscopy method could explain the property of the inclusion in a more sensitive manner, it also interpreted the conveying mechanism of BLF binding with inclusion complex. The molecular modeling result showed consistent results with Gaussian theory calculation; both of the two methods obtained the stable configuration of beta-CD-Res inclusion. The relevant result provided an experimental consequence for the pharmacology research of beta-cyclodextrin-resveratrol inclusion complex as well as offering a new reference to the future research of supramolecular inclusion compound.

Plant Biostimulant as an Environmentally Friendly Alternative to Modern Agriculture.

Ensuring the safety of crop production presents a significant challenge to humanity. Pesticides and fertilizers are commonly used to eliminate external interference and provide nutrients, enabling crops to sustain growth and defense. However, the addition of chemical substances does not meet the environmental standards required for agricultural production. Recently, natural sources such as biostimulants have been found to help plants with growth and defense. The development of biostimulants provides new solutions for agricultural product safety and has become a widely utilized tool in agricultural. The review summarizes the classification of biostimulants, including humic-based biostimulant, protein-based biostimulant, oligosaccharide-based biostimulant, metabolites-based biostimulants, inorganic substance, and microbial inoculant. This review attempts to summarize suitable alternative technology that can address the problems and analyze the current state of biostimulants, summarizes the research mechanisms, and anticipates future technological developments and market trends, which provides comprehensive information for researchers to develop biostimulants.

Improvement of surface stability of Zn anode by a cost-effective ErCl3 additive for realizing high-performance aqueous zinc-ion batteries.

Rechargeable aqueous-zinc ion batteries (AZIB) have notable benefits in terms of high safety and low cost. Nevertheless, the challenges, such as dendrite growth, zinc anode corrosion, and hydrogen evolution reaction, impede its practical implementation. Hence, this study proposes the introduction of an economical ErCl3 electrolyte additive to stabilize the Zn anode surface and address the aforementioned issues. The introduced Er3+ will cover the raised zinc dendrite surface and weaken the "tip effect" on the surface of the zinc anode via the "electrostatic shielding" effect. Simultaneously, the introduced Cl- can reduce the polarization of the zinc anode. Due to the synergistic effect of Er3+ and Cl-, the zinc anode corrosion, dendrite growth and hydrogen evolution have been efficiently inhibited. As a result, the Zn||Zn-symmetric battery using ErCl3 additive can stably cycle for 1100 h at 1 mA cm-2, 1 mAh cm-2, and exhibit a high average coulomb efficiency (99.2 %). Meanwhile, Zn||MnO2 full battery based on ErCl3-added electrolyte also demonstrates a high reversible capacity of 157.1 mAh/g after 500 cycles. Obviously, the capacity decay rate of the full battery is also improved, only 0.113 % per cycle. This study offers a straightforward and economically efficient method for stabilizing the zinc anode and realizing high-performance AZIBs.

Discovery of a novel nucleoside immune signaling molecule 2'-deoxyguanosine in microbes and plants.

INTRODUCTION: Beneficial microorganisms play essential roles in plant growth and induced systemic resistance (ISR) by releasing signaling molecules. Our previous study obtained the crude extract from beneficial endophyte Paecilomyces variotii, termed ZNC (ZhiNengCong), which significantly enhanced plant resistance to pathogen even at 100 ng/ml. However, the immunoreactive components of ZNC remain unclear. Here, we further identified one of the immunoreactive components of ZNC is a nucleoside 2'-deoxyguanosine (2-dG). OBJECTIVES: This paper intends to reveal the molecular mechanism of microbial-derived 2'-deoxyguanosine (2-dG) in activating plant immunity, and the role of plant-derived 2-dG in plant immunity. METHODS: The components of ZNC were separated using a high-performance liquid chromatography (HPLC), and 2-dG is identified using a HPLC-mass spectrometry system (LC-MS). Transcriptome analysis and genetic experiments were used to reveal the immune signaling pathway dependent on 2-dG activation of plant immunity. RESULTS: This study identified 2'-deoxyguanosine (2-dG) as one of the immunoreactive components from ZNC. And 2-dG significantly enhanced plant pathogen resistance even at 10 ng/ml (37.42 nM). Furthermore, 2-dG-induced resistance depends on NPR1, pattern-recognition receptors/coreceptors, ATP receptor P2K1 (DORN1), ethylene signaling but not salicylic acid accumulation. In addition, we identified Arabidopsis VENOSA4 (VEN4) was involved in 2-dG biosynthesis and could convert dGTP to 2-dG, and vne4 mutant plants were more susceptible to pathogens. CONCLUSION: In summary, microbial-derived 2-dG may act as a novel immune signaling molecule involved in plant-microorganism interactions, and VEN4 is 2-dG biosynthesis gene and plays a key role in plant immunity.

Benzene-1,3,5-tricarb-oxy-lic acid-5-(4-pyrid-yl)pyrimidine (1/1).

In the pyrimidine mol-ecule of the title compound, C(9)H(7)N(3)·C(9)H(6)O(6), the pyridine ring is oriented at 33.26 (11)° with respect to the pyrimidine ring. In the benzene-1,3,5-tricarb-oxy-lic acid mol-ecule, the three carb-oxy groups are twisted by 7.92 (9), 8.68 (10) and 17.07 (10)° relative to the benzene ring. Classical O-H⋯N and O-H⋯O hydrogen bonds and weak C-H⋯O and C-H⋯N hydrogen bonds occur in the crystal structure.

Multiple forms of vitamin B6 regulate salt tolerance by balancing ROS and abscisic acid levels in maize root.

Salt stress causes osmotic stress, ion toxicity and oxidative stress, inducing the accumulation of abscisic acid (ABA) and excessive reactive oxygen species (ROS) production, which further damage cell structure and inhibit the development of roots in plants. Previous study showed that vitamin B6 (VB6) plays a role in plant responses to salt stress, however, the regulatory relationship between ROS, VB6 and ABA under salt stress remains unclear yet in plants. In our study, we found that salt stress-induced ABA accumulation requires ROS production, in addition, salt stress also promoted VB6 (including pyridoxamine (PM), pyridoxal (PL), pyridoxine (PN), and pyridoxal 5'-phosphate (PLP)) accumulation, which involved in ROS scavenging and ABA biosynthesis. Furthermore, VB6-deficient maize mutant small kernel2 (smk2) heterozygous is more susceptible to salt stress, and which failed to scavenge excessive ROS effectively or induce ABA accumulation in maize root under salt stress, interestingly, which can be restored by exogenous PN and PLP, respectively. According to these results, we proposed that PN and PLP play an essential role in balancing ROS and ABA levels under salt stress, respectively, it laid a foundation for VB6 to be better applied in crop salt resistance than ABA.

Benzene-1,4-diol-5-(1H-imidazol-1-yl)pyrimidine (1/1).

The asymmetric unit of title compound, C(7)H(6)N(4)·C(6)H(6)O(2), contains one 5-(1H-imidazol-1-yl)pyrimidine mol-ecule and two half benzene-1,4-diol mol-ecules; the benzene-1,4-diol mol-ecules are located on individual inversion centers. In the pyrimidine mol-ecule, the imidazole ring is twisted with respect to the pyrimidine ring at a dihedral angle of 25.73 (7)°. In the crystal, O-H⋯N hydrogen bonds link the mol-ecules to form supra-molecular chains. π-π stacking is also observed in the crystal, the centroid-centroid distance between parallel imdazole rings being 3.5543 (16) Å.

Silk Fibroin-Sheathed Conducting Polymer Wires as Organic Connectors for Biosensors.

Conductive polymers, owing to their tunable mechanical and electrochemical properties, are viable candidates to replace metallic components for the development of biosensors and bioelectronics. However, conducting fibers/wires fabricated from these intrinsically conductive and mechanically flexible polymers are typically produced without protective coatings for physiological environments. Providing sheathed conductive fibers/wires can open numerous opportunities for fully organic biodevices. In this work, we report on a facile method to fabricate core-sheath poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) PEDOT:PSS-silk fibroin conductive wires. The conductive wires are formed through a wet-spinning process, and then coated with an optically transparent, photocrosslinkable silk fibroin sheath for insulation and protection in a facile and scalable process. The sheathed fibers were evaluated for their mechanical and electrical characteristics and overall stability. These wires can serve as flexible connectors to an organic electrode biosensor. The entire, fully organic, biodegradable, and free-standing flexible biosensor demonstrated a high sensitivity and rapid response for the detection of ascorbic acid as a model analyte. The entire system can be proteolytically biodegraded in a few weeks. Such organic systems can therefore provide promising solutions to address challenges in transient devices and environmental sustainability.

Growth mechanism and photocatalytic activity of self-organized N-doped (BiO)2CO3 hierarchical nanosheet microspheres from bismuth citrate and urea.

Synthesis of nano-/microstructured functional materials with 3D hierarchical microspheres structure has provided new opportunities for optimizing their physical and chemical properties. This work revealed a new growth mechanism of self-organized N-doped (BiO)2CO3 hierarchical microspheres which were fabricated by hydrothermal treatment of bismuth citrate and urea without an additive. Based on time-dependent observation, several evolution processes were believed to account for the formation of the self-organized N-doped (BiO)2CO3 hierarchical microspheres. Initially, crystallized (BiO)4CO3(OH)2 particles were formed during the nucleation and crystallization processes. Subsequently, the intermediate (BiO)4CO3(OH)2 reacted with CO3(2-) to generate (BiO)2CO3 growth nuclei on the surface of the CO2 bubbles which can act as heterogeneous nucleation centers. Next, the (BiO)2CO3 growth nuclei aggregated together after the consumption of CO2 bubbles with the increased concentration of OH(-) and further grew to be nanosheets. The microspheres constructed by small nanosheets further grew with the consumption of small particles. Finally, all (BiO)4CO3(OH)2 transformed to the (BiO)2CO3 phase, accompanied by the doping of N element into the lattice of (BiO)2CO3, and thereby, the well-defined N-doped (BiO)2CO3 hierarchical microspheres were shaped. Depending on the distance between neighboring CO2 bubbles, the resulting microspheres can be linked or dispersed. Besides, the gradual release of CO2 bubbles and CO3(2-) played a crucial role in controlling the nucleation and growth process, resulting in different sizes of microspheres. The fabricated N-doped (BiO)2CO3 hierarchical microspheres displayed admirably efficient and durable photocatalytic activity under both UV and visible light towards removal of NO, which is mainly attributed to the introduction of N element and the special hierarchical structure. This work provides new insights into the controlled synthesis of photocatalytic nano/microstructures for potential environmental and energetic applications.

Molecular docking and 3D-QSAR studies on beta-phenylalanine derivatives as dipeptidyl peptidase IV inhibitors.

Three-dimensional quantitative structure-activity relationship (3D-QSAR) and molecular docking studies were carried out to explore the binding of 73 inhibitors to dipeptidyl peptidase IV (DPP-IV), and to construct highly predictive 3D-QSAR models using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). The negative logarithm of IC(50) (pIC(50)) was used as the biological activity in the 3D-QSAR study. The CoMFA model was developed by steric and electrostatic field methods, and leave-one-out cross-validated partial least squares analysis yielded a cross-validated value (r(2)(cv)) of 0.759. Three CoMSIA models developed by different combinations of steric, electrostatic, hydrophobic and hydrogen-bond fields yielded significant r(2)(cv) values of 0.750, 0.708 and 0.694, respectively. The CoMFA and CoMSIA models were validated by a structurally diversified test set of 18 compounds. All of the test compounds were predicted accurately using these models. The mean and standard deviation of prediction errors were within 0.33 and 0.26 for all models. Analysis of CoMFA and CoMSIA contour maps helped identify the structural requirements of inhibitors, with implications for the design of the next generation of DPP-IV inhibitors for the treatment of type 2 diabetes.

Design, synthesis, and evaluation of 2-phenoxy-indan-1-one derivatives as acetylcholinesterase inhibitors.

A series of 2-phenoxy-indan-1-one derivatives have been designed, synthesized, and tested as acetylcholinesterase inhibitors. The most potent compound exhibited high AChE inhibitory activity (IC50 = 50 nM), and the molecular docking study indicated that it was nicely accommodated by AChE.