Interaction Of Complexes Research Articles

Evaluating the estrogen degradation potential of laccase and peroxidase from Bacillus ligniniphilus L1 through integrated computational and experimental approaches.

This study investigated the degradation potential of laccase and catalase-peroxidase from the extremophilic marine bacterium Bacillus ligniniphilus L1 against endogenous and synthetic estrogen compounds using an integrated computational and experimental approach. Molecular docking identified five estrogen compounds exhibiting reliable bindings with enzymes, which were then subjected to enzyme activity assays. The degradation potential of the two enzymes against five selected estrogen compounds were investigated and compared with their commercial counterparts. Laccase from L1 showed higher degradation potential against estrone (47.02 % without and 62.21 % with ABTS) compared to commercial laccase (39 % without and 54.20 % with ABTS). For estradiol valerate, commercial laccase showed a slightly higher degradation (52.47 %) than L1 laccase (49.94 %), but with ABTS, L1 laccase performed better (74.15 % vs. 68.03 %). Notably, L1 catalase-peroxidase demonstrated significantly higher degradation for all tested compounds compared to its commercial counterpart with efficiencies of 96.16 %, 89.09 %, 74.94 %, 64.91 %, and 62.80 % against estropipate, quinestrol, estradiol valerate, estriol and estrone, respectively, revealing its potential for commercial applications. Molecular dynamics simulations revealed the interaction and stability of enzyme-estrogen complexes, with MMGBSA binding energy calculations supporting experimental results. These findings highlight the usefulness of the computational approach in elucidating the molecular mechanisms underlying enzyme-mediated bioremediation of environmental contaminants.

Biosorption of Pb2+, Cd2+ and Zn2+ from aqueous solutions by Agrobacterium tumefaciens S12 isolated from acid mine drainage

Heavy metal pollution is a global environmental issue, and microorganisms play a crucial role in the bioremediation of heavy metal-contaminated wastewater. The study isolated heavy metal-resistant bacterium and observed their absorption ability toward Pb2+, Cd2+ and Zn2+. We isolated Agrobacterium tumefaciens S12 from acid mine drainage. The various factors influencing its adsorption performance, including pH, biomass dosage, initial metal ion concentration, and adsorption temperature, were investigated in detail. Chemisorption controls the adsorption rate due to the results better fitted by pseudo-second order kinetics. The maximum adsorption capacities of Pb2+, Cd2+ and Zn2+ on A. tumefaciens S12 were 234, 58 and 51 mg g−1 at 30 °C from Langmuir isotherm, respectively. The adsorption processes for the three heavy metal ions were spontaneous and exothermic in nature. In bimetallic systems, biosorption of Pb2+ ions was preferential to that of Cd2+ and Zn2+. Furthermore, scanning electron microscopy coupled to energy dispersive spectroscopy, Fourier-transform infrared spectra and X-ray photoelectron spectroscopy analysis demonstrated that the adsorption mechanisms include ion-exchange, complexation interaction between the heavy metal ions and the functional groups on the surface of biomass. The obtained results indicated that A. tumefaciens S12 can be applied as an efficient biosorbent in bioremediation technology to sequestrate heavy metal ions from aqueous solution.

Adsorption characteristics and mechanism of novel ink melanin composite modified chitosan for Cd(II) in water.

In this study, chitosan (CS), carboxymethyl chitosan (CMCS), and chitosan quaternary ammonium salt (HACC) were successfully loaded with ink melanin (ME) as efficient adsorbents for Cd(II) removal. The results of batch adsorption experiments and structural characterization showed that the modified CS loaded with ME improved the adsorption capacity of the composites for Cd(II). The pseudo-second-order kinetic and Langmuir equations were better suited to describe the batch adsorption experiments. The adsorption of Cd(II) was chemisorption with desirable adsorption effect when the concentration of the three composites was 0.5 mg/mL and the pH value was neutral. Among them, HACC-ME demonstrated remarkable Cd(II) adsorption performance (107.18 mg/g) and sustained an 85 % efficiency in Cd(II) removal over five adsorption-desorption cycles. Ion exchange, complexation, electrostatic attraction, and hydrophobic interaction were the primary mechanisms for Cd(II) removal. Overall, HACC-ME could be employed as a low-cost and highly efficient new natural adsorbent material for the removal of Cd(II) ions from wastewater. These findings illuminate pathways for the development of efficient and novel natural adsorbent materials for environmental cleanup purposes.

New Pd(II)-pincer type complexes as potential antitumor drugs: synthesis, nucleophilic substitution reactions, DNA/HSA interaction, molecular docking study and cytotoxic activity.

Two new complexes of Pd(II), [Pd(L1)Cl]Cl (Pd1) and [Pd(L2)Cl]Cl (Pd2), (where L1 = N2,N6-bis(5-methylthiazol-2-yl)pyridine-2,6-dicarboxamide and L2 = N2,N6-di(benzo[d]thiazol-2-yl)pyridine-2.6-dicarboxamide) were synthesized. Characterization of the complexes was performed using elemental analysis, IR, 1H NMR spectroscopy and MALDI-TOF mass spectrometry. The nucleophilic substitution reactions of complexes with L-Methionine (L-Met), L-Cysteine (L-Cys) and guanosine-5'-monophosphate (5'-GMP) were studied by stopped-flow method at physiological conditions (pH = 7.2 and 37 °C). Complex Pd1 was more reactive than Pd2 in all studied reactions, while the order of reactivity of the selected ligands was: L-Met > L-Cys > 5'-GMP. The interaction of complexes with calf thymus-DNA (CT-DNA) was studied by Uv-Vis absorption and fluorescence emission spectroscopy. Competitive binding studies with intercalative agent ethidium bromide (EB) and minor groove binder Hoechst 33258 were performed as well. Both complexes interacted with DNA through intercalation and minor groove binding, where the latter was preferred. Additionally, the interaction of Pd1 and Pd2 complexes with human serum albumin (HSA) was studied employing fluorescence quenching spectroscopy. The results indicate a moderate binding affinity of complexes, with slightly stronger binding of the Pd1. Fluorescence competition experiments with site-markers (eosin Y and ibuprofen) for HSA were used to locate the binding site of Pd1 to the HSA. Additionally, the interaction with DNA and HSA was studied by molecular docking and the revealed results were in good agreement with the experimentally obtained ones. Pd1 complex exhibited cytotoxicity toward human (HCT116) and mouse cell lines (CT26) of colorectal cancer, mouse (4T1) and human (MDA-MB468) breast cancer lines and non-cancerous mouse mesenchymal stem cells (mMSC). In addition, Pd1 complex demonstrated significant selectivity towards cancer cells over non-cancerous mMSC, indicating a high potential to eliminate malignant cells without affecting normal cells. It induced apoptosis in CT26 cells, effectively arrested the cell cycle in the S phase, and selectively down-regulated cyclin D and cyclin E. Moreover, it can alter the expression of cell cycle regulators by increasing p21 and decreasing p-AKT. These findings confirm its ability to disrupt key tumor cell survival signals and suggest that the Pd1 complex is a potent candidate for effective cancer treatment.

Face-to-Face Gold Porphyrins.

The interaction of square-planar metal complexes through space is of fundamental interest and relevant for the potential cooperative catalysis of two metal complex sites. In order to elucidate gold/gold, gold/porphyrin, and porphyrin/porphyrin interactions in the formal oxidation states +III and +II (after reduction) and in the excited triplet state after light excitation, a Pacman bis(gold(III)) complex [Au2(DPD)][PF6]2 with square-planar face-to-face gold(porphyrin) moieties has been prepared and characterized. Absorption and luminescence spectroscopy, cyclic voltammetry, and EPR spectroscopy on [Au2(DPD)]n+ and a mononuclear reference are complemented by DFT and TDDFT calculations.

Biogenic fabrication of spinel nickel ferrite imprinted on Bifurcaria bifurcata Macro-Alga activated carbon for the adsorption of ciprofloxacin and metronidazole

The rise in globalization and industrialization has led to an increase in population, increasing improperly treated discharge containing dyes, pharmaceuticals, pesticides etc in the water bodies. This has led to the need to remove these contaminants from water sources. The NiFe@BBAL adsorbent was developed and analyzed using various techniques such as FTIR, XRD, SEM, and XPS. The effectiveness of the NiFe@BBAL in adsorbing Ciprofloxacin (CIP) and metronidazole (MET) in water was tested. The adsorption of CIP and MET, both individually and in mixtures, was studied. The kinetic sorption experiments showed that the adsorption followed a pseudo-second-order model, with a higher R2 of 0.9934 for MET compared to 0.9916 for CIP. This suggests that the rate-limiting step is chemisorption. The primary adsorption mechanisms for both CIP and MET were hydrogen bonding, hydrophobic interactions, and electrostatic interactions, while CIP also involved electrostatic and metal complexation interactions. The NiFe@BBAL effluent showed no toxic effects on bacteria, indicating that no harmful material was leached in the effluent. The NiFe@BBAL demonstrated excellent performance and stability in removing 97.64% CIP and 97.62% MET in single contaminant experiments, and 57.33% CIP and 70.69% MET in cocktail mixture experiments. This can be attributed to the smaller structure of MET compared to CIP, allowing it better access to the active site, leading to higher adsorption. Furthermore, the repeated use of the adsorbent proved to be stable in the removal of CIP and MET over five cycles, demonstrating that the material is sustainable and suitable for large-scale experiments.

Development of polyfunctionalized biochar modified with manganese oxide and sulfur for immobilizing Hg(II) and Pb(II) in water and soil and improving soil health

Mercury (Hg) and lead (Pb) pose significant risks to human health due to their high toxicity and bioaccumulative properties. This study aimed to develop a novel biochar composite (HMB-S), polyfunctionalized with manganese dioxide (α-MnO2) and sulfur functional groups, for the effective immobilization of Hg(II) and Pb(II) from contaminated environments. HMB-S demonstrated superior adsorption capacities of 190.1 mg/g for Hg(II) and 259.9 mg/g for Pb(II), which significantly surpasses the capacities of unmodified biochar (HB) and biochar functionalized solely with Mn (HMB). Mechanistic studies revealed that the immobilization of these metals by HMB-S involved ion exchange, mineral precipitation, surface complexation, and electrostatic interactions. In soil incubation experiments, HMB-S significantly decreased the levels of extractable Hg(II) and Pb(II) compared to the control, reducing the mobility of these metals and converting 17 % of Hg(II) and 26 % of Pb(II) into less bioavailable residual forms. Pot experiments confirmed that all tested biochar materials (HB, HMB, and HMB-S) promoted spinach growth in contaminated soils, with HMB-S being the most effective at lowering Hg(II) and Pb(II) uptake by plants. Additionally, analysis of soil microbial communities indicated that HMB-S altered community composition and increased the relative abundance of metal-resistant bacteria. These findings highlight the potential of polyfunctionalized biochar HMB-S as an effective remediation strategy for Hg and Pb contamination in soil and aqueous environments.

Microbial community composition and co-occurrence network analysis of the rhizosphere soil of the main constructive tree species in Helan Mountain of Northwest China

To understand the microbial diversity and community composition within the main constructive tree species, Picea crassifolia, Betula platyphylla, and Pinus tabuliformis, in Helan Mountain and their response to changes in soil physicochemical factors, a high throughput sequencing technology was used to analyze the bacterial and fungal diversity and community structure. RDA (Redundancy Analysis) and Pearson correlation analysis were used to explore the influence of soil physicochemical factors on microbial community construction, and co-occurrence network analysis was conducted on the microbial communities. The results showed that the fungal and bacterial diversity was highest in B. platyphylla, and lowest in P. crassifolia. Additionally, the fungal/bacterial richness was greatest in the rhizosphere soils of P. tabuliformis and B. platyphylla. RDA and Pearson correlation analysis revealed that NN (nitrate nitrogen) and AP (available phosphorus) were the main determining factors of the bacterial community, while NN and SOC (soil water content) were the main determining factors of the fungal community. Pearson correlation analysis between soil physicochemical factors and the alpha diversity of the microbial communities revealed a significant positive correlation between pH and the bacterial and fungal diversity, while SOC, TN (total nitrogen), AP, and AN (available nitrogen) were significantly negatively correlated with the bacterial and fungal diversity. Co-occurrence network analysis revealed that the soil bacterial communities exhibit richer network nodes, edges, greater diversity, and greater network connectivity. Indicating that bacterial communities exhibit more complex and stable interaction patterns in soil. This study reveals the complex interactive relationship between microbial communities and soil physicochemical factors in forest ecosystems. By analyzing the response of rhizosphere microbial communities of major tree species in Helan Mountain to nutrient dynamics and pH changes, we can deepen our understanding of the role of microorganisms in regulating ecosystem functions and provide theoretical basis for soil improvement and ecological restoration strategies.

A recyclable and high porosity vinasse-based biochar with enhanced superficial active sites for antibiotics recovery

Antibiotic pollution in water bodies is a global environmental issue. For adsorbing antibiotic residues, biochar produced by direct high temperature pyrolysis faces challenges in balancing adsorption capacity and recyclability due to limited active sites. Thus, a recyclable and high-porosity vinasse-based biochar was developed via co-pyrolysis of K2FeO4 one-pot method. The co-pyrolysis biochar's surface area was augmented by 143 times, from 3.4 m²/g to 490.9 m²/g. The maximum theoretical adsorption capacity of the co-pyrolysis biochar for norfloxacin (NOR) increased from 4.4 mg/g to 364.9 mg/g, an approximate 83-fold enhancement. The surface of the biochar was rich in active groups (C-O, C-Fe, and -OH), which acted as the active sites to enhance the adsorption of NOR. The adsorption mechanism involved a variety of interactions, including pore-filling, hydrogen bond, π-π interactions, surface complexation, and electrostatic interactions. Importantly, the biochar is magnetic and can be recycled attributed to the generation of ferriferous oxides during the carbonization. After three cycles of reuse, the adsorption efficiency of vinasse-based biochar for NOR still exceeded 70 %. Such biochar prepared by this facile and feasible co-pyrolysis method show the potential to enhance active sites for removal of antibiotic from aquatic systems.

DNA interaction and cytotoxicity of a new asymmetric dimer cobalt(II) complex [Co(phen)2(Cl2)]3(H2O).[Co(phen)2(Cl)(H2O)](Cl)

The new, unusual and asymmetric cobalt(II) complex, [Co(phen)2(Cl2)]3(H2O).[Co(phen)2(Cl)(H2O)](Cl) (phen ​= ​1,10-phenanthroline), has been synthesized and characterized structurally by regular spectral and single crystal XRD analysis. An asymmetric complex crystallized in a monoclinic system with space group P21/c, a ​= ​14.093(5) Å, b ​= ​24.089(5) Å, c ​= ​14.241(5) Å, α ​= ​90.000(5)°, β ​= ​98.010(5)°, and γ ​= ​90.000(5)°. DNA binding interactions of complex with calf thymus DNA (CT-DNA) has investigated by UV–Vis absorption, ethidium bromide displacement assay, viscometric and cyclic voltammetric titrations, and the results infer an intercalation mode of binding. Complex cleaves effectively plasmid pBR322 DNA, and exhibits remarkable cytotoxic activity against human colon cancer cell line (HCT15).

Local potential energy density – A DFT analysis and the local binding energy in complexes with multiple interactions

A recently developed method, so-called local potential energy density, LPED, provides the binding energy density of intra/intermolecular interactions. The LPED cannot directly give the binding energy of intra/intermolecular interactions. However, it can indirectly give the binding energy through the linear equation between LPED and supramolecular binding energy, SME. In addition, the LPED can be used to obtain the SME of local or individual interactions indirectly for the case of complexes with multiple interactions, which cannot be obtained for any other method to our knowledge. The calculation of the LPED was evaluated with three different levels of theory using density functional methods. The linearity of LPED and SME between the reference level of theory (ωB97X-D/aug-cc-pVTZ) and the other levels of theory are similar among the studied levels of theory. In addition, LPED was used indirectly to obtain the local binding energy of intermolecular interactions of complexes with multiple interactions, such as the EDTA-Ca+2 and the fosfomycin-Ca+2.

The Antioxidant Effects of Trypsin-Hydrolysate Derived from Abalone Viscera and Fishery By-Products, and the Angiotensin-I Converting Enzyme (ACE) Inhibitory Activity of Its Purified Bioactive Peptides.

Abalone is a rich source of nutrition, the viscera of which are discarded as by-product during processing. This study explored the biological activities of peptides derived from abalone viscera (AV). Trypsin-hydrolysate of AV (TAV) was purified into three fractions using a Sephadex G-10 column. Nine bioactive peptides (VAR, NYER, LGPY, VTPGLQY, QFPVGR, LGEW, QLQFPVGR, LDW, and NLGEW) derived from TAV-F2 were sequenced. LGPY, VTPGLQY, LGEW, LDW, and NLGEW exhibited antioxidant properties, with IC50 values of 0.213, 0.297, 0.289, 0.363, and 0.303 mg/mL, respectively. In vitro analysis determined that the peptides VAR, NYER, VTPGLQY, QFPVGR, LGEW, QLQFPVGR, and NLGEW inhibited ACE, with IC50 values of 0.104, 0.107, 0.023, 0.023, 0.165, 0.004, and 0.146 mg/mL, respectively. The binding interactions of ACE-bioactive peptide complexes were investigated using docking analysis with the ZDCOK server. VTPGLQT interacted with HIS513 and TYR523, and QLQFPVGR interacted with HIS353, ALA354, GLU384, HIS513, and TYR523, contributing to the inhibition of ACE activity. They also interacted with amino acids that contribute to stability by binding to zinc ions. QFPVGR may form complexes with ACE surface sites, suggesting indirect inhibition. These results indicate that AV is a potential source of bioactive peptides with dual antioxidant and anti-hypertensive dual effects.

Ni(II)-selenosemicarbazones complexes as promising anticancer and anti-tubercular agents: Synthesis, characterization, molecular docking and binding studies with HSA and ct-DNA

Reaction of nickel(II) acetate with selenosemicarbazones (2-HOxsesc, 3-MeHOxsesc, 6-ClHOxsesc, 3-HIndsesc, 3-AcHIndsesc, 9-HAnsesc, 1-HNapsesc, 2-HNapsesc) in 1:2 (M:L) molar ratio yielded complexes of formula, [Ni(sesc)2] 1–8 (sesc = 2-Oxsesc 1, 3-MeOxsesc 2, 6-ClOxsesc 3, 3-Indsesc 4, 3-AcIndsesc 5, 9-Ansesc 6, 1-Napsesc 7, 2-Napsesc 8).Complexes are characterized using elemental analysis, FTIR, NMR (1H and 13C) spectroscopy and Mass spectrometry. The full optimized energy for 2-HOxsesc and its complex was found through Density Functional Theory calculation using B3LYP level and predicted geometry parameters are compared with literature. Selenosemicarbazones and their complexes were tested for their anti-tuberculosis activity against M. tuberculosis H37RV strain and anticancer activity against PA-1 and DU145cell lines. The anti-TB activity of 3-AcHIndsesc (MIC = 25 μg/mL) got exceptionally enhanced on complexation with Ni(II) (complex 5, MIC = 0.8 μg/mL). Anticancer activity of ligands have got enhanced on complexation with Ni(II) metal ion and best results were obtained in case of complex 5 (PA-1, IC50 =1.28; DU145, IC50 =3.83). The binding constant of 6.5 × 103M-1 and 3 × 104M−1 obtained from absorption spectroscopy (UV–Vis) indicates strong binding of complex 5 with HSA and ct-DNA. The molecular interaction of 3-AcHIndsesc and complex 5 with mycobacterium tuberculosis enoyl reductase and DNA (PDB ID: 1BNA) were checked with docking studies. The docking studies with mycobacterium tuberculosis enoyl reductase and DNA (PDB ID: 1BNA) gave minimum binding energy of -8.9 Kcal/mol and -7.5 Kcal/mol respectively for complex 5. The docking results are in well agreement with experimental data.

Chemical assessment of three octahedral Ni(II) complexes with heterocyclic acylpyrazolone ligand: Crystal structure, DFT-NBO analysis, Hirshfeld and Magnetic study

We have synthesized three novel mononuclear Nickel(II) coordination complexes [Ni(DMBPTMP)2(EtOH)2], [Ni(PCBPMP)2(DMF)(H2O)] and [Ni(PCBPTMP)2(DMSO)2] with σ-donating acylpyarazolone ligands. All the complexes have been comprehensively characterized via FTIR, UV–Vis, TGA, and Magnetic study. Additionally, single crystal X-ray diffraction analysis was successfully used to characterize the three complexes. The findings showed that the geometry around Ni(II) is slightly distorted octahedral in [Ni(DMBPTMP)2(EtOH)2], [Ni(PCBPMP)2(DMF)(H2O)] complexes and also in the centrosymmetric [Ni(PCBPTMP)2(DMSO)2] complex. In all the complexes the metal is bischelated by two pyrazolone molecules via carbonyl and benzoyl carbonyl oxygen donors, but with a different configuration of ligands. In addition to the experimental studies and spectroscopic characteristics, DFT computational analysis and Natural bonding orbital (NBO) analysis have been performed using a B3LYP/LANL2DZ basis set for the optimization. All three Ni(II) complexes give three distinct absorption transitions which has been proved by Electronic spectral analysis. A paramagnetic nature of the complex is confirmed through magnetic study. Utilising Hirshfeld surface analysis, intermolecular interactions of complexes were evaluated.

Interfacial interactions between colloidal polystyrene microplastics and Cu in aqueous solution and saturated porous media: Model fitting and mechanism analysis

Microplastic (MP) and heavy metal pollution have received much attention. Few researches have been carried out on the influence of the interaction between MPs and heavy metals on their transport in saturated porous media, which concerns their fate. Therefore, the interaction mechanisms between colloidal polystyrene microplastics (PSMPs) and Cu were first carried out by applying batch adsorption experiments. Subsequently, the transport and retention of PSMPs and Cu in saturated porous media was explored through column experiments. The interaction process between PSMPs and Cu was further investigated using density functional theory (DFT) calculations. Findings demonstrated that PSMPs had strong adsorption capacity for Cu ((60.07 ± 2.57) mg g−1 at pH 7 and ionic strength 0 M) and the adsorption process was chemically dominated, non-uniform, and endothermic. The O-containing functional groups on PSMP surfaces showed essential roles in Cu adsorption, and the adsorption process mainly contained electrostatic and complexation interactions. In column experiments, Cu could inhibit PSMP transport by the cation bridging effect and changing the electrical properties of glass beads, while PSMPs may facilitate Cu transport through the carrying effect. These findings confirmed that interfacial interactions between MPs and Cu could influence their transport in saturated porous media directly, providing great environmental significance.

Layered double hydroxides/biochar composites for adsorptive removal of tetracycline and ciprofloxacin

Modification of biochar (BC) using layered double hydroxides (LDHs) is an anticipated strategy to strengthen the adsorption performance of BC. In this work, sawdust was used to prepare pristine BC to act as a matrix, and the MgFe-LDHs were selected as typical LDHs to prepare BC-LDHs composites via a coprecipitation technique, and the adsorption mechanisms toward tetracycline (TC) and ciprofloxacin (CIP) were evaluated. The effect of LDHs amount on the characteristics of BC-LDHs composites and the adsorption behavior and mechanisms of TC and CIP were also studied. Results showed that the loading of LDHs reduced the specific surface area and total pore volume of BC but developed more mesoporous structure in composites, created metal oxygen-containing functional groups (Mg–OH, Mg–O, Fe–O), and introduced a typical mineral (Mg6Fe2(OH)16CO3·4H2O) on the surface of the BC. The BC-1/3LDHs obtained by loading LDHs on 3 g BC exhibited the maximum adsorption capacity toward TC and CIP, and reached 77.04 mg∙g−1 and 66.74 mg∙g−1, respectively. The introduction of MgFe-LDHs greatly intensified the complexation interaction and hydrogen bonding of the composites. The Freundlich and pseudo-second-order models well-described the adsorption process of TC and CIP on BC-1/3LDHs. In addition, BC-1/3LDHs could adsorb TC and CIP in a wide range of pH values despite the interference of coexisting ions and also presented a good recycle utilization potential. Furthermore, the introduction of LDHs, especially BC-1/3LDHs, shifted the adsorption thermodynamic properties of BC. Overall, the prepared BC-1/3LDHs could be used as a promising adsorbent for the removal of TC and CIP from water environments.

A putative NF-Y complex interacting with ERD15 may positively regulate the expression of a peroxidase gene in response to stress in rapeseed (Brassica napus L.)

Drought stress is one of the major constraints on crop productivity, including rapeseed (Brassica napus L.). Nuclear factors Y (NF-Ys) are important transcription factors involved in plant responses to drought and other stresses. However, the underlying molecular mechanisms remain unclear in rapeseed. By silencing BnaNF-YA9 in rapeseed and transforming BnaNF-YA9 into the Arabidopsis mutant Atnf-ya5, we demonstrated that BnaNF-YA9 plays a positive role in drought resistance. To explore its regulatory mechanism, we performed protein-protein interaction analyses using various approaches. Our study revealed complex interactions among BnaNF-YA9, BnaNF-YB2, BnaNF-YC4, and EARLY RESPONSIVE TO DEHYDRATION 15 (ERD15), suggesting that these proteins form a multimember complex. We also showed that BnaNF-YA9 binds to the CCAAT element in the promoter of a BnaPRX gene, which encodes a peroxidase. Interestingly, overexpression of BnaNF-YC4 or BnaERD15 in Arabidopsis increased sensitivity to salt stress, drought, and abscisic acid. Our results support an NF-Y/ERD15/PRX cascade and suggest a complex regulatory network in rapeseed that may be important in maintaining ROS homeostasis during abiotic stress responses. Our findings provide insights into potential targets for improving drought resilience in crops.

Cryoprotective effect of wheat starch granular surface proteins on frozen HMW and LMW glutenins: Structure, property and functionality across length scales

Although frozen dough technology has demonstrated significant benefits, the mechanisms underlying dough deterioration during freezing remain unclear. To overcome this obstacle, the effect of freezing-induced deteriorations of wheat starch granular surface proteins (SGSPs)-high/low molecular weight (HMW/LMW) glutenins complexes were analyzed from the molecular to macroscopic scales. After 7 cycles of freezing/thawing treatment, SGSPs-LMW complex showed a higher antifreeze stability than SGSPs-HMW complex. The freezable water content of SGSPs-HMW increased from 32 % to 39 %, indicating a marked migration and recrystallization of ice. In this situation, the interactions of SGSPs-HMW complex were affected and destabilized, leading to partially denatured and depolymerized molecular structures. Furthermore, the bulk protein aggregation network was also dissociated under the ice tearing and splitting, which irreversibly collapsed to small molecular protein particles. In comparison, the resistance of SGSPs-LMW complex on continued network disruption appear to be the key to maintain the quality of frozen dough.

Amidation modified hollow composite microspheres as a self-floating adsorbent for efficient capture of anionic dye DB86 and heavy metal nickel (II).

The co-contamination of dyes and heavy metal ions often used as mordants poses potential risks to environment and public health, and is a challenging problem that needs to be solved in water treatment. Meanwhile, improving the solid-liquid separation capability of adsorbents is of great significance for the application of adsorption technology. Herein, amidation modified hollow composite microspheres were prepared using hollow glass microsphere (HGM) as matrix through hydrolysis and condensation of silane coupling agent (A-1100) and subsequent amidation reaction. The material (HGMNE) not only exhibited good adsorption performance for DB86 and Ni2+ but also had stable self-floating capability. The adsorption of DB86 by HGMNE is mainly carried out by the electrostatic interaction between positively charged quaternary amine nitrogen and negatively charged DB86, while the adsorption of Ni2+ is achieved by the carboxyl group in EDTA group through complexation interaction to adsorb Ni2+ to form Ni complex. This research not only is devoted to the utilization of HGMNE to achieve the co-removal of DB86 and Ni2+ and flexible self-floating solid-liquid separation but also verifies the feasibility and applicability of the modification method of introducing organic adsorption functional groups through amidation reaction, so as to expand the preparation path of HGM-based adsorbents.

Precipitation and diameter affect wood decomposition both directly and indirectly via deadwood traits and position

Woody plants are important components of dryland ecosystems. Our understanding of wood decomposition in drylands, an important component of biogeochemical cycling, is poor compared to that in mesic ecosystems. To uncovering the complex interactive effects of the different key drivers, we studied the effects of precipitation, position (aboveground and belowground), wood size and litter quality of plant species (four to five local species and one widespread woody species) on woody litter decomposition rates along a precipitation gradient from 37 to 369 mm, spanning five dryland sites. Wood dry matter content (DMC) was a critical negative predictor of wood decomposition in water-limited ecosystems. Thicker woody litter had lower decomposition rates (k values) directly because of smaller relative surface exposure, and indirectly through higher wood DMC or lower bark mass ratio (bark mass divided by wood mass for a given branch length). Mean annual precipitation (MAP) increased the k values both directly, and indirectly by decreasing the wood DMC and increasing the bark mass ratio due to species turnover. The k values of buried woody litter were mostly two to three times higher than litter on the soil surface, but not different at the extremely arid site. A steeper slope of the relationship between overall woody litter quality (particularly wood DMC) or annual precipitation and k values was observed belowground than aboveground, as related to the higher moisture belowground than aboveground. These findings highlight the complex interactions among climate (precipitation), litter position, size and quality on wood decomposition in drylands, thereby helping to improve our mechanistic understanding of dryland woody litter decomposition. We conclude that wood decomposition at the regional and local scales will influence biogeochemical cycling in drylands under future climate change through both direct effects of moisture and indirect effects of litter quality characteristics.