ß-1,3-GLUCANASE10 regulates tomato development and disease resistance by modulating callose deposition.

ß-1,3-Glucanases are considered key regulators responsible for the degradation of callose in plants, yet little is known about the role and mode of action of their encoding genes in tomato (Solanum lycopersicum). In the present study, we identified the ß-1,3-glucanase encoding gene ß-1,3-GLUCANASE10 (SlBG10) and revealed its regulation in tomato pollen and fruit development, seed production, and disease resistance by modulating callose deposition. Compared with wild-type (WT) or SlBG10 overexpressing (SlBG10-OE) lines, knockout of SlBG10 caused pollen arrest and failure to set fruit with reduced male rather than female fecundity. Further analyses showed that SlBG10-knockout promoted callose deposition in anther at the tetrad-to-microspore stages, resulting in pollen abortion and male sterility. Moreover, loss-of-function SlBG10 delayed degradation of endosperm cell wall calloses during cellularization and impeded early seed development. We also uncovered that Botrytis cinerea infection induces SlBG10 expression in WT tomato, and the knockout lines showed increased callose accumulation in fruit pericarps, reduced susceptibility to B. cinerea, and enhanced antioxidant capacity to maintain tomato fruit quality. However, the expression of genes encoding cell wall hydrolases decreased in SlBG10-knockout tomatoes and thus led to an increase in pericarp epidermal thickness, enhancement in fruit firmness, reduction of fruit water loss, and extension of tomato shelf life. These findings not only expand our understanding of the involvement of ß-1,3-glucanases as callose regulators in multiple developmental processes and pathogen resistance but also provide additional insight into the manipulation of multiagronomic traits for targeted tomato breeding.

Critical Functions of Soil Components for In Situ Persulfate Oxidation of Sulfamethoxazole: Inherent Fe(II) Minerals-Coordinated Nonradical Pathway.

Naturally occurring iron (Fe) minerals have been proved to activate persulfate (PS) to generate reactive species, but the role of soil-inherent Fe minerals in activating PS as well as the underlying mechanisms remains poorly understood. Here, we investigated sulfamethoxazole (SMX) degradation by PS in two Fe-rich soils and one Fe-poor soil. Unlike with the radical-dominant oxidation processes in Fe-poor soil, PS was effectively activated through nonradical pathways (i.e., surface electron-transfer) in Fe-rich soils, accounting for 68.4%-85.5% of SMX degradation. The nonradical mechanism was evidenced by multiple methods, including electrochemical, in situ Raman, and competition kinetics tests. Inherent Fe-based minerals, especially those containing Fe(II) were the crucial activators of PS in Fe-rich soils. Compared to Fe(III) minerals, Fe(II) minerals (e.g., ilmenite) were more liable to form Fe(II) mineral-PS* complexes to initiate the nonradical pathways, oxidizing adjacent SMX via electron transfer. Furthermore, mineral structural Fe(II) was the dominant component to coordinate such a direct oxidation process. After PS oxidation, low-crystalline Fe minerals in soils were transformed into high-crystalline Fe phases. Collectively, our study shows that soil-inherent Fe minerals can effectively activate PS in Fe-rich soils, so the addition of exogenous iron might not be required for PS-based in situ chemical oxidation. Outcomes also provide new insights into the activation mechanisms when persulfate is used for the remediation of contaminated soils.

D-ribose metabolic disorder and diabetes mellitus.

D-ribose, an ubiquitous pentose compound found in all living cells, serves as a vital constituent of numerous essential biomolecules, including RNA, nucleotides, and riboflavin. It plays a crucial role in various fundamental life processes. Within the cellular milieu, exogenously supplied D-ribose can undergo phosphorylation to yield ribose-5-phosphate (R-5-P). This R-5-P compound serves a dual purpose: it not only contributes to adenosine triphosphate (ATP) production through the nonoxidative phase of the pentose phosphate pathway (PPP) but also participates in nucleotide synthesis. Consequently, D-ribose is employed both as a therapeutic agent for enhancing cardiac function in heart failure patients and as a remedy for post-exercise fatigue. Nevertheless, recent clinical studies have suggested a potential link between D-ribose metabolic disturbances and type 2 diabetes mellitus (T2DM) along with its associated complications. Additionally, certain in vitro experiments have indicated that exogenous D-ribose exposure could trigger apoptosis in specific cell lines. This article comprehensively reviews the current advancements in D-ribose's digestion, absorption, transmembrane transport, intracellular metabolic pathways, impact on cellular behaviour, and elevated levels in diabetes mellitus. It also identifies areas requiring further investigation.

Effects of d-ribose on human erythrocytes: Non-enzymatic glycation of hemoglobin, eryptosis, oxidative stress and energy metabolism.

d-Ribose is not only an important component of some biomacromolecules, but also an active pentose with strong reducibility and non-enzymatic glycation ability. Previous studies reported the diverse role of d-ribose in different cells. In this study, the effects of d-ribose on non-enzymatic glycation of hemoglobin (Hb), as well as eryptosis, oxidative stress and energy metabolism of erythrocytes were observed by molecular fluorescence spectrophotometry, multi-wavelength spectrophotometry, high-pressure liquid chromatography (HPLC), mass spectrometry (MS) and flow cytometer. The results showed that d-ribose had the strongest non-enzymatic glycation ability to Hb in vitro when compared with other monosaccharides, and could enter the erythrocytes in a concentration-dependent manner, which was not inhibited by the specific glucose transporter 1 (GLUT1) inhibitor WZB117. In addition, d-ribose incubation increased the HbA1c, hemolysis, eryptosis, and ROS level of erythrocytes significantly more than that of d-glucose, however, no changes were observed in the levels of ATP, NADPH, and other intermediate energy metabolites in d-ribose treatment. Therefore, the strong non-enzymatic glycation ability of d-ribose may play an important role in erythrocyte damage.

Loops Mediate Agonist-Induced Activation of the Stimulator of Interferon Genes Protein.

The stimulator of interferon genes (STING) is an important therapeutic target for cancer diseases. The activated STING recruits downstream tank-binding kinase 1 (TBK1) to trigger several important immune responses. However, the molecular mechanism of how agonist molecules mediate the STING-TBK1 interactions remains elusive. Here, we performed molecular dynamics simulations to capture the conformational changes of STING and TBK1 upon agonist binding. Our simulations revealed that multiple helices (α5-α7) and especially three loops (loop 6, loop 8, and C-terminal tail) of STING participated in the allosteric mediation of the STING-TBK1 interactions. Consistent results were also observed in the simulations of the constitutive activating mutant of STING (R284S). We further identified α5 as a key region in this agonist-induced activation mechanism of STING. Free-energy perturbation calculations of multiple STING agonists demonstrated that an alkynyl group targeting α5 is a determinant for agonist activities. These results not only offer deeper insights into the agonist-induced allosteric mediation of STING-TKB1 interactions but also provide a guidance for future drug development of this important therapeutic target.

New Insight into the Natural Detoxification of Cr(VI) in Fe-Rich Surface Soil: Crucial Role of Photogenerated Silicate-Bound Fe(II).

Photoexcitation of natural semiconductor Fe(III) minerals has been proven to generate Fe(II), but the photogeneration of Fe(II) in Fe-rich surface soil as well as its role in the redox biogeochemistry of Cr(VI) remains poorly understood. In this work, we confirmed the generation of Fe(II) in soil by solar irradiation and proposed a new mechanism for the natural reductive detoxification of Cr(VI) to Cr(III) in surface soil. The kinetic results showed that solar irradiation promoted the reduction of Cr(VI) in Fe-rich soils, while a negligible Cr(VI) reduction was observed in the dark. Fe(II), mainly in the form of silicate-bound Fe(II), was generated under solar irradiation and responsible for the reduction of Cr(VI) in soils, which was evidenced by sequential extraction, transmission electron microscopy with electron energy loss spectroscopy, and electron transfer calculation. Photogenerated silicate-bound Fe(II) resulted from the massive clay-iron (hydr)oxide associations, consisting of iron (hydr)oxides (e.g., hematite and goethite) and kaolinite. These associations could generate Fe(II) under solar irradiation either via intrinsic excitation to produce photoelectrons or via the ligand-to-metal charge transfer process after the formation of clay-iron (hydr)oxide-organic matter complexes, which was proven by photoluminescence spectroscopy and X-ray photoelectron spectroscopy. These findings highlight the important role of photogenerated Fe(II) in Cr(VI) reduction in surface soil, which advances a fundamental understanding of the natural detoxification of Cr(VI) as well as the redox biogeochemistry of Cr(VI) in soil.

Paspalines C-D and Paxillines B-D: New Indole Diterpenoids from Penicillium brefeldianum WZW-F-69.

Five new indole diterpenoids named paspaline C-D (1-2) and paxilline B-D (3-5), as well as eleven known analogues (6-16), were identified from fungus Penicillium brefeldianum strain WZW-F-69, which was isolated from an abalone aquaculture base in Fujian province, China. Their structures were elucidated mainly through 1D- and 2D-NMR spectra analysis and ECD comparison. Compound 1 has a 6/5/5/6/6/8 hexacyclic ring system bearing 2,2-dimethyl-1,3-dioxocane, which is rare in natural products. Compound 2 has an unusual open F-ring structure. The cytotoxic activities against 10 cancer cell lines and antimicrobial activities against model bacteria and fungi of all compounds were assayed. No compound showed antimicrobial activity, but at a concentration of 1 µM, compounds 1 and 6 exhibited the highest inhibition rates of 71.2% and 83.4% against JeKo-1 cells and U2OS cells, respectively.

Adsorption Performance and Mechanism of Synthetic Schwertmannite to Remove Low-Concentration Fluorine in Water.

Fluorine (F) in water has a negative effect on the environment and human health. Schwertmannite has potential remediation to contamination in solution. In this study, the adsorption mechanism and influencing factors of synthetic schwertmannite for low-concentration F were studied through batch experiments. The results suggested that the adsorption of F by schwertmannite reached equilibrium after about 60 min, and the adsorption efficiency exceeded 94%. The experimental data can be best-fit by the pseudo-second-order kinetic and Langmuir models well. Schwertmannite showed effective adsorption at pH 4, dosage 1.5 g L-1, low temperature, and low concentration of co-existing anion. The adsorption process was a spontaneous and exothermic reaction, which was dominated by chemical adsorption. FT-IR and XPS spectra analysis revealed that F adsorption on schwertmannite through the surface complexation and anion exchange reaction between SO42- and OH- with F-, especially the primary role of OH-. The results can provide theoretical support for the schwertmannite application in the treatment of F-containing wastewater.

Batch Adsorption and Column Leaching Studies of Aniline in Chinese Loess Under Different Hydrochemical Conditions.

Through batch adsorption and column leaching experiments, this study aimed to investigate the adsorption and transport behavior of aniline in loess and related mechanism under different hydrochemical conditions. Batch experiments results indicated that aniline adsorption reached equilibrium after about 120 min, and the adsorption fitted the pseudo-second-order kinetic and Freundlich models well. The adsorption was spontaneous and exothermic process, indicating the aniline adsorbed by inherent colloidal particles (ICPs) tended to transport. Low pH value, ionic strength and temperature benefitted the adsorption. Column experiments results under different ionic strengths (100, 10 and 1 mM) confirmed the potential transport of aniline. The FT-IR spectra have further suggested that aniline was adsorbed by the ICPs through hydrogen-bond, hydrophobic effect and cation exchange interactions. Low ionic strength was advantageous for the adsorption of aniline in loess and the stabilities of ICPs in solution, but enhanced the co-transport probability of ICPs with aniline in loess.

CMFAN: Cross-Modal Feature Alignment Network for Few-Shot Single-View 3D Reconstruction.

Few-shot single-view 3D reconstruction learns to reconstruct the novel category objects based on a query image and a few support shapes. However, since the query image and the support shapes are of different modalities, there is an inherent feature misalignment problem damaging the reconstruction. Previous works in the literature do not consider this problem. To this end, we propose the cross-modal feature alignment network (CMFAN) with two novel techniques. One is a strategy for model pretraining, namely, cross-modal contrastive learning (CMCL), here the 2D images and 3D shapes of the same objects compose the positives, and those from different objects form the negatives. With CMCL, the model learns to embed the 2D and 3D modalities of the same object into a tight area in the feature space and push away those from different objects, thus effectively aligning the global cross-modal features. The other is cross-modal feature fusion (CMFF), which further aligns and fuses the local features. Specifically, it first re-represents the local features with the cross-attention operation, making the local features share more information. Then, CMFF generates a descriptor for the support features and attaches it to each local feature vector of the query image with dense concatenation. Moreover, CMFF can be applied to multilevel local features and brings further advantages. We conduct extensive experiments to evaluate the effectiveness of our designs, and CMFAN sets new state-of-the-art performance in all of the 1-/10-/25-shot tasks of ShapeNet and ModelNet datasets.

Crucial roles of soil inherent Fe-bearing minerals in enhanced Cr(VI) reduction by biochar: The electronegativity neutralization and electron transfer mediation.

Biochar has been used for soil Cr(VI) remediation in the last decade due to its enriched redox functional groups and good electrochemical properties. However, the role of soil inherent Fe-bearing minerals during the reduction of Cr(VI) has been largely overlooked. In this study, biochar with different electron-donating capacities (EDCs) was produced at 400 °C (BC400) and 700 °C (BC700), and their performance for Cr(VI) reduction in soils with varied properties (e.g., Fe content) was investigated. The addition of BC400 caused around 14.2-36.0 mg g-1 Cr(VI) reduction after two weeks of incubation in red soil, paddy soil, loess soil, and fluvo-aquic soil, while a less Cr(VI) was reduced by BC700 (2.57-16.7 mg g-1) with smaller EDCs. The Cr(VI) reduction by both biochars in different soils was closely related to Fe content (R2 = 0.93-0.98), so red soil with the richest Fe (14.8% > 1.79-3.49%) showed the best reduction capability, and the removal of soil free Fe oxides (e.g., hematite) resulted in 71.9% decrease of Cr(VI) reduction by BC400. On one hand, Fe-bearing minerals could increase the soil acidity, neutralize the surface negative charge of biochar, enhance the contact between Cr(VI) and biochar, and thus facilitate the direct Cr(VI) reduction by biochar in soils. On the other hand, Fe-bearing minerals could also facilitate the indirect Cr(VI) reduction by mediating the electron from biochar to Cr(VI) with the cyclic transformation of Fe(II)/Fe(III). This study demonstrates the key role of soil Fe-bearing minerals in Cr(VI) reduction by biochar, which advances our understanding on the biochar-based remediation mechanism of Cr(VI)-contaminated soils.

Enhanced microbial reduction of Cr(VI) in soil with biochar acting as an electron shuttle: Crucial role of redox-active moieties.

Biochar has been proven to participate in the biotic reduction of hexavalent chromium (Cr(VI)) in environment since its involvement may accelerate the extracellular electron transfer (EET). However, roles of the redox-active moieties and the conjugated carbon structure of biochar in this EET process remain unclear. In this study, 350 °C and 700 °C were selected to produce biochar with more O-containing moieties (BC350) or more developed conjugated structures (BC700), and their performances in the microbial reduction of soil Cr(VI) were investigated. Our results showed that BC350 presented a 241% increase of Cr(VI) microbial reduction after 7-day incubation, much higher than that of BC700 (39%), suggesting that O-containing moieties might play more important roles in accelerating the EET process. Biochar, especially BC350 could serve as an electron donor for microbial anaerobic respiration, but its contribution (73.2%) as an electron shuttle for EET was dominant to the enhanced Cr(VI) reduction. The positive correlation between electron exchange capacities (EECs) of pristine and modified biochars and the corresponding maximum reduction rates of Cr(VI) evidenced the crucial role of redox-active moieties in electron shuttling. Moreover, EPR analysis suggested the nonnegligible contribution of semiquinone radicals in biochars to the accelerated EET process. This study demonstrates the crucial role of redox-active moieties, i.e., O-containing moieties in mediating the EET process during the microbial reduction of Cr(VI) in soil. Findings obtained will advance the current understanding of biochar as an electron shuttle participating in the biogeochemical processes of Cr(VI).

Sleep loss impairs intestinal stem cell function and gut homeostasis through the modulation of the GABA signalling pathway in Drosophila.

Sleep is essential for maintaining health. Indeed, sleep loss is closely associated with multiple health problems, including gastrointestinal disorders. However, it is not yet clear whether sleep loss affects the function of intestinal stem cells (ISCs). Mechanical sleep deprivation and sss mutant flies were used to generate the sleep loss model. qRT-PCR was used to measure the relative mRNA expression. Gene knock-in flies were used to observe protein localization and expression patterns. Immunofluorescence staining was used to determine the intestinal phenotype. The shift in gut microbiota was observed using 16S rRNA sequencing and analysis. Sleep loss caused by mechanical sleep deprivation and sss mutants disturbs ISC proliferation and intestinal epithelial repair through the brain-gut axis. In addition, disruption of SSS causes gut microbiota dysbiosis in Drosophila. As regards the mechanism, gut microbiota and the GABA signalling pathway both partially played a role in the sss regulation of ISC proliferation and gut function. The research shows that sleep loss disturbed ISC proliferation, gut microbiota, and gut function. Therefore, our results offer a stem cell perspective on brain-gut communication, with details on the effect of the environment on ISCs.

Learning protein fitness landscapes with deep mutational scanning data from multiple sources.

One of the key points of machine learning-assisted directed evolution (MLDE) is the accurate learning of the fitness landscape, a conceptual mapping from sequence variants to the desired function. Here, we describe a multi-protein training scheme that leverages the existing deep mutational scanning data from diverse proteins to aid in understanding the fitness landscape of a new protein. Proof-of-concept trials are designed to validate this training scheme in three aspects: random and positional extrapolation for single-variant effects, zero-shot fitness predictions for new proteins, and extrapolation for higher-order variant effects from single-variant effects. Moreover, our study identified previously overlooked strong baselines, and their unexpectedly good performance brings our attention to the pitfalls of MLDE. Overall, these results may improve our understanding of the association between different protein fitness profiles and shed light on developing better machine learning-assisted approaches to the directed evolution of proteins. A record of this paper's transparent peer review process is included in the supplemental information.

STING agonist-boosted mRNA immunization via intelligent design of nanovaccines for enhancing cancer immunotherapy.

Messenger RNA (mRNA) vaccine is revolutionizing the methodology of immunization in cancer. However, mRNA immunization is drastically limited by multistage biological barriers including poor lymphatic transport, rapid clearance, catalytic hydrolysis, insufficient cellular entry and endosome entrapment. Herein, we design a mRNA nanovaccine based on intelligent design to overcome these obstacles. Highly efficient nanovaccines are carried out with machine learning techniques from datasets of various nanocarriers, ensuring successful delivery of mRNA antigen and cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) to targets. It activates stimulator of interferon genes (STING), promotes mRNA-encoded antigen presentation and boosts antitumour immunity in vivo, thus inhibiting tumour growth and ensuring long-term survival of tumour-bearing mice. This work provides a feasible and safe strategy to facilitate STING agonist-synergized mRNA immunization, with great translational potential for enhancing cancer immunotherapy.

Sequence-based drug design as a concept in computational drug design.

Drug development based on target proteins has been a successful approach in recent decades. However, the conventional structure-based drug design (SBDD) pipeline is a complex, human-engineered process with multiple independently optimized steps. Here, we propose a sequence-to-drug concept for computational drug design based on protein sequence information by end-to-end differentiable learning. We validate this concept in three stages. First, we design TransformerCPI2.0 as a core tool for the concept, which demonstrates generalization ability across proteins and compounds. Second, we interpret the binding knowledge that TransformerCPI2.0 learned. Finally, we use TransformerCPI2.0 to discover new hits for challenging drug targets, and identify new target for an existing drug based on an inverse application of the concept. Overall, this proof-of-concept study shows that the sequence-to-drug concept adds a perspective on drug design. It can serve as an alternative method to SBDD, particularly for proteins that do not yet have high-quality 3D structures available.

Quercetin Prevents Intestinal Stem Cell Aging via Scavenging ROS and Inhibiting Insulin Signaling in Drosophila.

Adult stem cells, a class of cells that possess self-renewal and differentiation capabilities, modulate tissue regeneration, repair, and homeostasis maintenance. These cells undergo functional degeneration during aging, resulting in decreased tissue regeneration ability and increased disease incidence. Thus, it is essential to provide effective therapeutic solutions to preventing the aging-related functional decline of stem cells. Quercetin (Que) is a popular natural polyphenolic flavonoid found in various plant species. It exhibits many beneficial effects against aging and aging-related diseases; however, its efficacy against adult stem cell aging remains largely unclear. Drosophila possesses a mammalian-like intestinal system with a well-studied intestinal stem cell (ISC) lineage, making it an attractive model for adult stem cell research. Here, we show that Que supplementation could effectively prevent the hyperproliferation of ISCs, maintain intestinal homeostasis, and prolong the lifespan in aged Drosophila. In addition, we found that Que could accelerate recovery of the damaged gut and improve the tolerance of Drosophila to stressful stimuli. Furthermore, results demonstrated that Que prevents the age-associated functional decline of ISCs via scavenging reactive oxygen species (ROS) and inhibiting the insulin signaling pathway. Overall, our findings suggest that Que plays a significant role in delaying adult stem cell aging.

Graph neural network approaches for drug-target interactions.

Developing new drugs remains prohibitively expensive, time-consuming, and often involves safety issues. Accurate prediction of drug-target interactions (DTIs) can guide the drug discovery process and thus facilitate drug development. Non-Euclidian data such as drug-like molecule structures, key pocket residue structures, and protein interaction networks can be represented effectively using graphs. Therefore, the emerging graph neural network has been rapidly applied to predict DTIs, and proved effective in finding repositioning drugs and accelerating drug discovery. In this review, we provide a brief overview of deep neural networks used in DTI models. Then, we summarize the database required for DTI prediction, followed by a comprehensive introduction of applications of graph neural networks for DTI prediction. We also highlight current challenges and future directions to guide the further development of this field.

Initial ecological restoration assessment of an urban river in the subtropical region in China.

Rivers in urbanised cities are often polluted, black, and odorous, with poor water quality and deteriorated ecology. Despite many river restoration studies, assessments of ecological responses to river restoration practices remain scant. Benthic animals are useful biological indicators showing the change and succession of river ecosystems; however, previous studies have mainly focussed on a few target species without considering overall ecosystem integrity. Here, we used a multi-index biological assessment method, benthic index of biological integrity (B-IBI) to assess ecological responses to river restoration of the Shahe River in subtropical region of China. Spatiotemporal changes in the macrobenthos community structure after restoration were monitored to explore species succession. We found that the number of macrobenthos species increased from 16 to 42, with the emergence of some pollution-sensitive species during the restoration period. Molluscs showed widespread recovery, and their relative proportions almost doubled from 12.5% to 24.4%. Oligochaetes and chironomids were the pioneer species in the recovering communities, while gastropod molluscs and pollution-sensitive aquatic insects were transitional species that first settled during the initial recovery period. Based on our survey data, 25 candidate metrics were selected, and five core metrics (total taxa, Simpson diversity index, percentage of crustaceans and molluscs, percentage of predators, and percentage of collector-gatherers) were identified after screening to establish the B-IBI. Our analysis revealed a distinct improvement in the overall health of the river, with the proportions of "excellent" and "good" sites increasing from zero to 28.6% and from 14.3% to 42.9%, respectively. A correlation analysis indicated that water flow, molluscs, and total phosphorus content were the three drivers of ecological recovery in the Shahe River. Overall, our study demonstrates the importance of governance and restoration of rivers in tropical and subtropical cities, and provides valuable evidence that can guide the design and evaluation of river restoration works.

Nitrogen species control the interaction between NO3--N reduction and aniline degradation and microbial community structure in the oxic-anoxic transition zone.

Contrary to the fact that NO3--N can serve as electron acceptor to promote organics degradation, it was also found NO3--N reduction does not necessarily promote organics degradation. We speculate nitrogen (N) species may control the interaction between NO3--N reduction and organics degradation via shifting related microbial community structure. To prove the hypothesis, oxic-anoxic transition zone (OATZ) microcosms simulated by lake water and sediment were conducted with the addition of N species (NO3--N, NO2--N, and NH4+-N) and aniline as typical organics. High-throughput sequencing was used to analyze the microbial community structure and functional enzyme in the microcosms. Results show that, NO2--N inhibited NO3--N reduction while enhanced aniline degradation. For NH4+-N, it promoted NO3--N reduction when NH4+-N/NO3--N concentration ratio ≤ 2 and inhibited aniline degradation when NH4+-N/aniline concentration ratio ≥ 0.5. The presence of NO2--N or NH4+-N weakened the interaction between NO3--N reduction and aniline degradation, which might be caused by significant changes in the diversity and abundance of microbial communities controlled by N species. The microbial mechanism indicates that NO2--N weakened the interaction by affecting both denitrification enzyme activity and electron transfer capability, while NH4+-N weakened the interaction mainly by affecting electron transfer capability. These results imply that N species, as well as other electron acceptors and donors, in the contaminated OATZ should be fully considered, when performing in situ remediation technology of NO3--N reduction.