N-acetylglucosaminidase Activity Research Articles

Effectiveness of a tissue conditioner containing antifungals in a rat model of denture stomatitis.

This study investigated the effectiveness of a drug-modified tissue conditioner in an animal model of denture stomatitis. Wistar rats wore a Candida albicans-contaminated palatal device for 4 days. Next, nystatin (Nys) or chlorhexidine (Chx) were added to a tissue conditioner in their raw or β-cyclodextrin-complexed (βCD) forms at their minimum inhibitory concentrations. As controls, one group was not subjected to any procedure (NC), one group used sterile devices, one group had denture stomatitis but was not treated (DS), and another had the devices relined with the tissue conditioner without the addition of any drug (Soft). After 4 days of treatment, treatment effectiveness was assessed visually, histologically, and through CFU count, and myeloperoxidase (MPO) and N-acetylglucosaminidase (NAG) assays. Rats from the Soft, Nys, Nys:βCD, and Chx groups presented a significant decrease in the microbial load compared with the untreated group. Treatment groups showed lower MPO and NAG activity compared to the non-treated group. The addition of antifungals to a soft tissue conditioner can be a promising approach for denture stomatitis treatment.

Response of Soil CO2 Emission to Addition of Biochar and Dissolved Organic Carbon along a Vegetation Restoration Gradient of Subtropical China

Biochar, as a soil amendment, has been widely confirmed to increase soil carbon sequestration. However, how biochar addition affects soil carbon changes during the vegetation restoration process is still unclear, which constrains our ability to explore biochar’s application in the technology of soil carbon sequestration in forests. We conducted an incubation experiment on biochar and dissolved organic matter (DOM) addition to soil at three stages of revegetation (degraded land (DS), plantation forest (PS), and secondary natural forest (NS) in Changting County in Fujian province, China) to investigate the effects of vegetation restoration, biochar, DOM, and their interaction on soil CO2 emission and its relative mechanisms. We found that the accumulative release of CO2-C in the NS and PS soils was 7.6 and 6.8 times higher, respectively, in comparison to that from the DS soil. In the DS, biochar addition significantly increased the accumulative release of CO2-C, soil pH, NH4+-N content, qCO2, phenol oxidase, and peroxidase activities. Peroxidase activities were positively correlated with the accumulative release of CO2-C, and oxidase was the most important direct factor influencing the accumulative release of CO2-C in the DS. However, the accumulative release of CO2-C, soil NH4+-N content, qCO2, β-glucosidase, and N-acetylglucosaminidase activities was significantly reduced after the application of biochar in the PS and NS. These two hydrolases were positively associated with the accumulative release of CO2-C, and hydrolase was the most vital direct factor influencing the accumulative release of CO2-C from the PS and NS soils. The positive effect of DOM addition on CO2 emission under biochar application declined with a vegetation restoration age increase. Our results indicated that biochar could alter microbial physiological processes, inhibit qCO2 and hydrolase activities, and further decrease CO2 emission in relatively fertile soil from the PS and NS; but in the relatively barren soil from the DS, biochar might promote CO2 emission by stimulating microorganisms to enhance qCO2 and oxidase activities.

Urbanization-induced soil organic carbon loss and microbial-enzymatic drivers: insights from aggregate size classes in Nanchang city, China.

Soil microorganisms and enzymes play crucial roles in soil organic carbon (SOC) sequestration by promoting soil aggregate formation and stability and by participating in SOC cycling and accumulation. However, the effects by which soil microorganisms and enzymes act as mediators driving dynamic changes in SOC during rapid urbanization remain unclear. Therefore, this study selected the built-up area of Nanchang City, China (505 km2), as the study area. Sampling surveys were conducted using 184 sample plots stratified based on the proportion of impermeable surface area to distinguish different urbanization levels. The driving factors of dynamic changes in SOC of different aggregates during the process of urbanization were analyzed using the soil microbial community and enzyme activities. The results demonstrated that with an increase in urbanization intensity, both SOC content and stock exhibited a significant decline (p < 0.05). The highest SOC stock and contribution rate were observed in the 0.25-1 mm aggregates, and they were significantly influenced by urbanization (p < 0.05). In addition, the biomass of gram-positive bacteria (G+) and actinomycetota, and the activities of N-acetylglucosaminidase and acid phosphatase (AP) were significantly higher in low-urbanization areas than in high-urbanization areas (p < 0.05). SOC of each aggregate was positively correlated with fungi, arbuscular mycorrhizal fungi, G+, gram-negative bacteria, actinomycetota, protozoa, β-1,4-glucosidase, N-acetylglucosaminidase, AP, urease, and catalase. Compared to soil enzymes, soil microorganisms exhibited a greater role in SOC sequestration (22.7%). Additionally, a structural equation model indicated that urbanization can directly or indirectly lead to a decrease in SOC of aggregates by altering soil physicochemical properties and affecting microbial and enzyme dynamics. However, the larger vegetation characteristics index mitigate the negative impacts of urbanization on SOC. Overall, urbanization had a negative impact on soil carbon storage. In the future, it is important to consider strategies that focus on improving soil nutrients, maintaining soil structure, protecting existing urban trees, and enhancing plant diversity during the urbanization process. These measures can help increase soil microbial biomass and enzyme activity, thereby improving soil and aggregate-related SOC content. The study could contribute to enhancing carbon sequestration in urban greenspaces.

Understory vegetation had important impact on soil microbial characteristics than canopy tree under N addition in a Pinus tabuliformis plantation

Forest ecosystem is a complex community, and its soil microbes play a vital role in global matter cycling. However, the patterns of rhizosphere soil microbial characteristics among tree-shrub-grass and their responses to nitrogen (N) deposition are still unclear. This study evaluated the microbial biomasses, processes (gas fluxes), and enzyme activities in the rhizosphere soils of tree (Pinus tabuliformis), shrub (Rosa xanthina), and grass (Carex lanceolata) and their responses to N addition (0, 3, 6, 9 g N m−2 y−1 corresponding to N0, N3, N6, N9) in a P. tabuliformis plantation. (1) Microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), microbial biomass phosphorus (MBP) contents, as well as CO2, CH4 flux rates in the rhizosphere soil of C. lanceolata were significantly higher than those in the rhizosphere soils of P. tabuliformis and R. xanthina (P < 0.05). The activities of alkaline phosphatase (ALT), leucine aminopeptidase (LAP), β-glucosidase (BG), D-cellulosidase (CBH), N-acetyl-glucosaminidase (NAG), and xylosidase (XYL) in the rhizosphere soils of C. lanceolata and R. xanthina were significantly higher than those in the rhizosphere soil of P. tabuliformis. (2) Soil MBC content, N2O, and CH4 flux rates increased after N addition, while the CO2 flux rate decreased. MBP content initially increased and then reduced with N additions, and the maximum values observed in N3 or N9 treatments. (3) In the rhizosphere soil of P. tabuliformis, N addition enhanced the NAG, BG, CBH, and XYL activities. While low N increased and high N decreased these enzyme activities in the rhizosphere soils of C. lanceolata and R. xanthina, with the maximum values obtained in N3 treatment. (4) N addition directly reduced the CO2 flux rate and indirectly enhanced the gas flux rate by increasing soil MBC and MBP contents. Species change indirectly affected the microbial biomass and enzyme activity by altering soil chemical properties, which eventually affected gas flux rates. Our study emphasizes the effects of tree-shrub-grass on soil microbial characteristics, which can improve the evaluation of soil ecological processes and responses to N deposition in forest ecosystems.

Are silymarin and N-acetylcysteine able to prevent liver damage mediated by multiple factors? Findings against ethanol plus LPS-induced liver injury in mice.

This study investigated the effect of N-acetylcysteine (NAC) and silymarin (SIL) in the liver of mice exposed to ethanol and lipopolysaccharides (LPS).Mice were divided into fourgroups (n = 6): naive, vehicle, NAC (200 mg/kg), and SIL (200 mg/kg). Treatments were given orally (po) once daily for 10 days. Liver injury was induced by administration of ethanol (30%, po) for 10 days, once daily, followed by a single administration of LPS (2 mg/kg, ip) 24 h before euthanasia. After the treatment period, animals were euthanized, and liver and blood samples were collected.NAC, but not SIL, prevented the increase in oxalacetic glutamic transaminase (OGT) and pyruvic glutamic transaminase (PGT) serum levels. NAC and SIL did not restore levels of reduced glutathione or hepatic malonaldehyde. The treatments with NAC or SIL showed no difference in the activity of glutathione S-transferase, superoxide dismutase, and catalase compared to vehicle group. Myeloperoxidase and N-acetylglucosaminidase activities are increased, as well as the IL-6 and IL-10 levels in the liver. The treatment with NAC, but not SIL, reduced the N-acetylglucosaminesactivity and the IL-6 and IL-10 amount in the liver. Histological findings revealed microsteatosis in the vehicle group, which was not prevented by SIL but was partially reduced in animals receiving NAC.Unlike other liver injury models, NAC (200 mg/kg) or SIL (200 mg/kg) did not positively affect antioxidant patterns in liver tissue of animals exposed to ethanol plus LPS, but NAC treatment displays anti-inflammatory properties in this model.

Long-term warming of a forest soil reduces microbial biomass and its carbon and nitrogen use efficiencies

Global warming impacts biogeochemical cycles in terrestrial ecosystems, but it is still unclear how the simultaneous cycling of carbon (C) and nitrogen (N) in soils could be affected in the longer-term. Here, we evaluated how 14 years of soil warming (+4 °C) affected the soil C and N cycle across different soil depths and seasons in a temperate mountain forest. We used H218O incorporation into DNA and 15N isotope pool dilution techniques to determine gross rates of C and N transformation processes. Our data showed different warming effects on soil C and N cycling, and these were consistent across soil depths and seasons. Warming decreased microbial biomass C (−22%), but at the same time increased microbial biomass-specific growth (+25%) and respiration (+39%), the potential activity of β-glucosidase (+31%), and microbial turnover (+14%). Warming reduced gross rates of protein depolymerization (−19%), but stimulated gross N mineralization (+63%) and the potential activities of N-acetylglucosaminidase (+106%) and leucine-aminopeptidase (+46%), and had no impact on gross nitrification (+1%). Microbial C and N use efficiencies were both lower in the warming treatment (−15% and −17%, respectively). Overall, our results suggest that long-term warming drives soil microbes to incorporate less C and N into their biomass (and necromass), and to release more inorganic C and N to the environment, causing lower soil C and N storage in this forest, as indicated by lower soil C and total N contents. The decreases in microbial CUE and NUE were likely triggered by increasing microbial P constraints in warmed soils, limiting anabolic processes and microbial growth and promoting pervasive losses of C and N from the soil.

Short-term prescribed fire-induced changes in soil microbial communities and nutrients in native rangelands of Florida

Prescribed burning is widely used land management strategy to reduce the risks of wildfire and to achieve a wide range of ecological, economic, and societal benefits. However, it can also affect carbon (C), nitrogen (N), and phosphorus (P) cycling with potential subsequent effects on soil microbial communities. This study examined the short-term effects of prescribed burning on soil chemical properties, potential enzyme activities, and bacterial and fungal community composition in native rangelands of Florida. Fire-induced responses were assessed immediately (2 days) and 2 to 3 months after a prescribed fire event. Soil pH, total C, and extractable NH4+ and P concentration declined after fire. Total N concentration increased 2 days after fire but returned to initial level 2 to 3 months after fire. Prescribed fire elicited no observable effects on soil total P and extractable Ca, K, Mg, Mn, Fe, and Al concentration. Reductions in potential beta glucosidase and N-acetyl glucosaminidase activity were observed 2 days after fire but returned at pre-fire levels after 2–3 months. Bacterial and fungal diversity and community composition at the phylum level showed no short-term changes. At the Order level, bacterial Desulfurellales increased while fungal Eurotiales and Pleosporales decreased 2 days after fire. Prescribed burning had minimal effect on soil microbial community composition in the short-term, probably due to limited effects of fire on soil heating and rapid post-fire vegetative recovery. Although the impacts of prescribed fire on soil properties have been widely acknowledged, this study is the first to document short-term fire-induced soil microbial responses in subtropical native rangelands of Florida. This work contributes to a wealth of evidence indicating limited impacts of prescribed fire on soil microbial community composition.

Influence of red wine polysaccharides on cytochrome P450 enzymes and inflammatory parameters in tumor models

The soluble fraction of polysaccharides from cabernet franc red wine (SFP) previously showed antitumoral effects by modulating the immune system. The present study tested the hypothesis that the SFP can regulate CYPs in vitro in HepG2 cells and in vivo in Walker-256 tumor-bearing rats. The SFP was used in the following protocols: (i) solid tumor, (ii) liquid tumor, and (iii) chemopreventive solid tumor. The SFP reduced solid tumor growth in both solid tumor protocols but did not inhibit liquid tumor development. The SFP reduced total CYP levels in the solid and liquid tumor protocols and reduced the gene expression of Cyp1a1 and Cyp2e1 in rats and CYP1A2 in HepG2 cells. An increase of N-acetylglucosaminidase activity was observed in all SFP-treated rats, and TNF-α levels increased in the solid tumor protocol in the vehicle, SFP, and vincristine (positive control) groups. The chemopreventive solid tumor protocol did not modify CYP levels in the liver or intestine or N-acetylglucosaminidase and myeloperoxidase activity in the liver. The in vitro digestion and nuclear magnetic resonance analyses suggested that SFP was minimally modified in the gastrointestinal system. In conclusion, SFP inhibited CYPs both in vivo and in vitro, likely as a result of its immunoinflammatory actions.

Sex-specific effects of propiconazole on the molting of the Chinese mitten crab (Eriocheir sinensis)

Given the inevitable exposure of Eriocheir sinensis (E. sinensis) to fungicides in rice-crab co-culture systems, understanding the potential effect of fungisides is important for practical application. Molting is a crucial development process of E. sinensis, which is regulated by endocrine system and genetic factors, and is susceptible to exogenous chemicals. However, the impact of fungicides application on the molting of E. sinensis have been rarely reported. In the present study, propiconazole, a widely used fungicide for rice disease management, was found to exert potential effects on the molting of E. sinensis at residual-related level in the rice-crab co-culture fields. After 14 days of short-term exposure to propiconazole, female crabs exhibited remarkably higher levels of hemolymph ecdysone than males. When the exposure was extended to 28 days, propiconazole markedly accelerated molt-inhibiting hormone expression by 3.3-fold, ecdysone receptor expression by 7.8-fold, and crustacean retinoid X receptor expression by 9.6-fold in male crabs, while it showed the opposite effect in females with suppressed gene expression. Propiconazole also induced the activity of N-acetylglucosaminidase in male crabs rather than females during the experiments. Our study suggests that propiconazole exerts sex-specific effects on the molting of E. sinensis. The impact of propiconazole application in the rice-crab co-culture systems remains more assessment to avoid affecting the growth of cultured E. sinensis.

Dietary lipids management: are there any benefits from the prevention and treatment of 4T1 murine breast carcinoma?

This study investigated the effect of vegetable and fish oils with different n-3 / n-6 PUFAS ratios on the lipoprotein profile and on the development of murine breast cancer 4T1. Female Balb/c mice (6-7 weeks) received diets containing 4.0% fat during seven weeks. On the fourth week, animals were inoculated into the posterior left flank with 2.5 × 106 4T1 cells. Body weight and food intake were registered and the profile serum lipoproteins was determined. Tumor volume, histopathological and immunohistochemical studies, myeloperoxidase and N-acetylglucosaminidase activities, TNF-α, hemoglobin and VEGF levels were analysed. The highest n-3 / n-6 ratio was found in fish oil (15.8:1), followed by linseed (2.4:1), canola (1:2.1) and soybean (1:9.4) oils. Body weight, food and caloric intake, lipoprotein profile, tumor weight, tumor evolution and histopathological analysis were not different. Canola oil increased cell proliferation when compared to soybean oil, and fish oil changed the inflammatory response and increased VEGF in tumors compared to other groups. The type of fatty acid and the high ratio of n-3 / n-6 PUFAs in the diet influenced cell proliferation and inflammation in the tumor differentially, highlighting the increase of neutrophils and VEGF levels in animals fed on fish oil.

Potential implications of biochar and compost on the stoichiometry-based assessments of soil enzyme activity in heavy metal-polluted soils

Biochar and compost application in soil has been proved as an environmental management and soil remediation strategy for upgrading soil quality and growth-promoting soil microorganisms. A detailed examination of the fluctuations and stoichiometric interactions between β-glucosidase (BG), N-acetylglucosaminidase (NAG), leucine aminopeptidase (LAP), and acid phosphatase (AP) after applying biochar and compost to the heavy metal soils was conducted in the paper. However, biochar stimulated the activity of AP and inhibited BG, NAG, and LAP. Compost and biochar-compost might strengthen BG, NAG, LAP, and AP activities. Redundancy analysis discovered that the crucial parameters that affected soil enzyme activity were TN, NO3−-N, and TP. However, the stoichiometric ratio of C/N, C/P, and N/P with the application of the biochar, compost, and biochar-compost could be changed. While alleviating the P-limitation in soils under Cu stress, biochar may also alleviate the C-limitation in soils under As, Cd, and Zn stress. Compost and biochar-compost application alleviated C-limitation in heavy-metal (Cu, As, Cd, and Zn) polluted soil. This work will help us further understand the stoichiometry and energy restrictions of biochar and compost on ecological functional enzymes.

Living grass mulching improves soil enzyme activities through enhanced available nutrients in citrus orchards in subtropical China.

Living grass mulching (LGM) is an important orchard floor management that has been applied worldwide. Although LGM can effectively enhance soil nutrient availability and fertility, its effects on microbial-mediated soil nutrient cycling and main drivers are unclear. Meanwhile, the variation of enzyme activities and soil nutrient availability with LGM duration have been rarely studied. This study aims to explore the effects of mulching age and soil layer on enzyme activities and soil nutrients in citrus orchards. In this study, three LGM (Vicia villosa) treatments were applied, i.e., mulching for eight years, mulching for four years, and no mulching (clean tillage). Their effects on the enzyme activities and soil nutrients were analyzed in different soil layers of citrus orchards in subtropical China, i.e., 0-10, 10-20, and 20-40cm. Compared to clean tillage, mulching for four years had fewer effects on enzyme activities and soil nutrients. In contrast, mulching for eight years significantly increased available nitrogen (N), phosphorus (P) nutrients, β-glucosidase, and cellobiohydrolase activities in the soil layer of 0-20cm. In the soil layer of 0-40cm, microbial biomass carbon (C), N, P, N-acetylglucosaminidase, leucine aminopeptidase, and acid phosphatase activities also increased (P < 0.05). Mulching for eight years significantly promoted C, N, and P-cycling enzyme activities and total enzyme activities by 2.45-6.07, 9.29-54.42, 4.42-7.11, and 5.32-14.91 times, respectively. Redundancy analysis shows that mulching treatments for eight and four years had soil layer-dependent positive effects on soil enzyme activities. Microbial C and P showed the most significant positive correlation with enzyme activities, followed by moisture content, organic C, and available N (P < 0.05). Available nutrients contributed almost 70% to affect enzyme activities significantly and were the main drivers of the enzyme activity variation. In summary, LGM could improve soil enzyme activities by increasing available nutrients. The promotion effect was more significant under mulching for eight years. Therefore, extending mulching age and improving nutrient availability are effective development strategies for sustainable soil management in orchard systems. Our study can provide valuable guidelines for the design and implementation of more sustainable management practices in citrus orchards.

Greenhouse gas emission responses to different soil amendments on the Loess Plateau, China

Soil amendments are commonly used to reduce greenhouse gas (GHG) emissions by altering the physical, biological, and chemical qualities of soil, but the mechanism by which this is achieved still vague. This two-year study surveyed the influences of biochar (BC), Bacillus mucilaginosus (BM), and Bacillus subtilis (BS) on the physical, enzyme activities, soil microbial and GHG emissions. Results indicated that soil amendment addition decreased the activities of β-glucosidase (BG), cellobiohydrolase (CBH), β-xylosidase (BX), sucrase, cellulase by 8.81%, 8.99%, 22.08%, 59.46%, 74.61%, respectively, and increased N-acetylglucosaminidase (NAG) activity by 155.00%. Soil amendments had little effect on soil microbes, apart from those related to the C and N cycles, such as Proteobacteria, Mortierellomycota and Acidobacteriota. In addition, BC, BM, and BS amendments decreased mean cumulative CO2 emissions by 38.43%, 11.83%, and 38.54%, respectively. Cumulative N2O emissions from the BC treatment increased by 28.17% in 2019 and decreased by 37.22% in 2020. For the BM and BS treatments, cumulative N2O emissions did not significantly change in 2019 but decreased by 4.93% and 57.85% in 2020, respectively. Generally, soil amendments decreased the greenhouse emission intensity (GHGI) and global warming potential (GWP). Moreover, a structural equation model (SEM) revealed factors that directly or indirectly controlled GHG emissions, including NAG, BX, CBH, Proteobacteria, Mortierellomycota and Acidobacteriota. These factors were limited mainly by soil C and N substrates, such as ammonium-nitrogen (NH4+-N), available phosphorus (AP), and soil organic matter (SOM). Overall, soil amendments can reduce GHG emissions in the long term, but they are affected by many factors.However, soil amendments alone have limited effects on reducing GHG emissions on the Loess Plateau. Suggesting combining and applying biochar and plant growth-promoting rhizobacteria (PGPR) may enhance soil quality and alleviate GHG emissions.

Enzyme activity after applying alkaline biosolids to agricultural soil

Municipal wastewater biosolids are nutrient-rich residuals with potential as crop fertilizer, if their alkalinity does not adversely affect soil biochemical processes. This study assessed the potential soil enzyme activity after three annual applications of biosolids in a conventionally tilled field under silage corn ( Zea mays L.). Biosolids were municipal wastewater sludge treated by mesophilic anaerobic digestion, lime stabilization, or composting, compared with urea fertilizer and an unfertilized control. Generally, the potential soil enzyme activity did not change with biosolids application, but the N-acetylglucosaminidase activity increased in soil amended with lime-stabilized biosolids, which also had higher soil pH and greater soil NH4 + concentration.

Disease correction in mucopolysaccharidosis type IIIB mice by intraparenchymal or cisternal delivery of a capsid modified AAV8 codon-optimized NAGLU vector.

Mucopolysaccharidosis type IIIB (MPS IIIB) is an autosomal recessive lysosomal storage disease caused by mutations in the gene that encodes the protein N-acetyl-glucosaminidase (NAGLU). Defective NAGLU activity results in aberrant retention of heparan sulfate within lysosomes leading to progressive central nervous system (CNS) degeneration. Intravenous treatment options are limited by the need to overcome the blood-brain barrier and gain successful entry into the CNS. Additionally, we have demonstrated that AAV8 provides a broader transduction area in the MPS IIIB mouse brain compared with AAV5, 9 or rh10. A triple-capsid mutant (tcm) modification of AAV8 further enhanced GFP reporter expression and distribution. Using the MPS IIIB mouse model, we performed a study using either intracranial six site or intracisterna magna injection of AAVtcm8-codon-optimized (co)-NAGLU using untreated MPS IIIB mice as controls to assess disease correction. Disease correction was evaluated based on enzyme activity, heparan sulfate storage levels, CNS lysosomal signal intensity, coordination, activity level, hearing and survival. Both histologic and enzymatic assessments show that each injection method results in supranormal levels of NAGLU expression in the brain. In this study, we have shown correction of lifespan and auditory deficits, increased CNS NAGLU activity and reduced lysosomal storage levels of heparan sulfate following AAVtcm8-coNAGLU administration and partial correction of NAGLU activity in several peripheral organs in the murine model of MPS IIIB.

Nuclear receptor HR3 mediates transcriptional regulation of chitin metabolic genes during molting in Tribolium castaneum.

Chitin, a major component of insect cuticles, plays a critical role in insect molting and morphogenesis. Thus, coordination of chitin remodeling during insect development requires tight transcriptional control of the chitin metabolism genes involved in chitin synthesis, assembly and degradation. However, the molecular mechanism underlying transcriptional coordination of chitin metabolism genes during beetle development is not yet completely understood. We cloned the full-length cDNA encoding hormone receptor 3 (TcHR3) from Tribolium castaneum and showed a critical role of TcHR3 in modulating chitin metabolism gene expression during molting. Genome-wide transcriptome analysis of HR3-deficient old larvae using RNA sequencing analysis revealed a positive correlation between TcHR3 and transcription of chitin metabolism genes involved in chitin synthesis and degradation. In addition, HR3 overexpression significantly induced the gene promoter activity of N-acetylglucosaminidase 1 (NAG1) involved in chitin degradation and UDP-N-acetylglucosamine pyrophosphorylase 1 (UAP1) involved in chitin synthesis. Chromatin immunoprecipitation analysis revealed that HR3 could directly bind to HR3-response element of NAG1 and UAP1 promoters. Finally, HR3-deficient late instar larvae and prepupae exhibited defects in larval-larval and larval-pupal molting, respectively, leading to eventual larval death because developing larvae were trapped inside the old cuticle as a result of abnormal chitin metabolism. TcHR3 is a transcriptional regulator of chitin metabolic genes for molting of T.castaneum. Controlling the molting system by TcHR3 might be a new management strategy for selective control of red flour beetle infestation. © 2022 Society of Chemical Industry.

Extract of Tagetes erecta L., a medicinal plant rich in lutein, promotes gastric healing and reduces ulcer recurrence in rodents

Ethnopharmacological relevanceTagetes erecta L. (Asteraceae), popularly known as Aztec Marigold, is used in South America to treat several ailments. Despite reports that T. erecta flowers are used in folk medicine to treat gastrointestinal diseases, there is no study regarding its gastric healing effects. Aim of the studyThe effect of dry extract of T. erecta L. (DETe) in gastric healing and gastric ulcer recurrence was evaluated, contributing to the validation of the antiulcer potential of this medicinal plant. MethodsRats were treated orally with vehicle (1 ml/kg), omeprazole (20 mg/kg), or DETe (3, 30 or 300 mg/kg) for 7 days, twice a day. The lesion area was evaluated, and the levels of reduced glutathione (GSH) and lipoperoxides (LOOH) and the activity of the superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and myeloperoxidase (MPO) were measured. The ulcer recurrence was evaluated in mice and induced by interleukin (IL)-1β (1 μg/kg, i.p). The recurred area, gastric wall thickness, GSH and cytokines levels, MPO and N-acetylglucosaminidase (NAG) activities were measured. ResultsDETe accelerated the healing of gastric ulcers only at 300 mg/kg, reducing the ulcerated area by 66%. In parallel, DETe reduced LOOH levels, SOD, CAT and MPO activities, while increasing GST activity and mucin amount. In the recurrence model, DETe reduced the lesion area by 94%, and in parallel decreased the gastric wall thickness and TNF levels, while increasing IL-10 amount. ConclusionsCorroborating the popular use of T. erecta, DETe favors the antioxidant system and reduce gastric inflammation, accelerating the gastric healing process and reducing the ulcer recurrence.

Intercropping of Leguminous and Non-Leguminous Desert Plant Species Does Not Facilitate Phosphorus Mineralization and Plant Nutrition.

More efficient use of soil resources, such as nitrogen (N) and phosphorus (P), can improve plant community resistance and resilience against drought in arid and semi-arid lands. Intercropping of legume and non-legumes can be an effective practice for enhancing P mineralization uptake, and plant nutrient status. However, it remains unclear how intercropping systems using desert plant species impact soil-plant P fractions and how they affect N and water uptake capacity. Alhagi sparsifolia (a legume) and Karelinia caspia (a non-legume) are dominant plant species in the Taklamakan Desert in Xinjiang Province, China. However, there is a lack of knowledge of whether these species, when intercropped, can trigger synergistic processes and mechanisms that drive more efficient use of soil resources. Thus, in a field experiment over two years, we investigated the impact of monoculture and intercropping of these plant species on soil-plant P fractions and soil-plant nutrients. Both plant species’ foliar nutrient (N, P, and K) concentrations were higher under monoculture than intercropping (except K in K. caspia). Nucleic acid P was higher in the monoculture plots of A. sparsifolia, consistent with higher soil labile P, while metabolic P was higher in monoculture K. caspia, associated with higher soil moderately labile Pi. However, both species had a higher residual P percentage in the intercropping system. Soils from monoculture and intercropped plots contained similar microbial biomass carbon (MBC), but lower microbial biomass N:microbial biomass phosphorus (MBN:MBP) ratio associated with reduced N-acetylglucosaminidase (NAG) activity in the intercropped soils. This, together with the high MBC:MBN ratio in intercropping and the lack of apparent general effects of intercropping on MBC:MBP, strongly suggest that intercropping improved microbe N- but not P-use efficiency. Interestingly, while EC and SWC were higher in the soil of the K. caspia monoculture plots, EC was significantly lower in the intercropped plots. Plants obtained better foliar nutrition and soil P mineralization in monocultures than in intercropping systems. The possible positive implications of intercropping for reducing soil salinization and improving soil water uptake and microbial N-use efficiency could have advantages in the long term and its utilization should be explored further in future studies.

Soil Enzyme Activity and Stoichiometry: Linking Soil Microorganism Resource Requirement and Legume Carbon Rhizodeposition

Legumes provide multiple ecosystem services in agricultural systems. The objectives of this study were to evaluate the influence of different legumes through C rhizodeposition on the dynamics of C, N and P in soil and on microbial communities’ resource requirements. Legumes pea (Pisum sativum L.), faba bean (Vicia faba L.), white clover (Trifolium repens L.), crimson clover (Trifolium incarnatum L.) and non-legume wheat (Triticum aestivum L.) were grown in pots. Carbon rhizodeposition was quantified by using 13CO2 labeling, and six soil enzyme activities were measured: β-glucosidase (BG), arylamidase (ARYLN), N-acetyl-glucosaminidase (NAG), phosphatases (PHO) and alkaline and acid phosphatases (AKP and ACP). Enzyme stoichiometry approaches were applied. The results showed that BG, NAG and ACP activities were positively influenced by faba bean and clovers. Enzyme stoichiometry analysis revealed a limitation of microorganisms in C and P resources at the plant reproductive stage. These results were explained by plant functional traits. Plant biomass production, root total length, the ability of plants to rhizodeposit C and the C and N content of plant tissues were the main explicative factors. This study also shows that N and C nutrient supplies positively contribute to nutritional requirements and the growth of microorganisms and P availability in soil.

Disentangling drivers of soil microbial nutrient limitation in intensive agricultural and natural ecosystems

Characterized by continuous chemical fertilization, intensive agriculture generally reduces soil ecoenzymatic activities and nutrient mineralization, as well as alters the biomass production and microbial community composition. Soil acidification poses serious threats to the sustainable development of intensive agriculture. However, the mechanism of nutrient cycling and metabolism of soil microorganisms in response to soil acidification in intensive agriculture remains unclear. Herein, we studied the variations in ecoenzymatic stoichiometry of soil β-glucosidase (BG), cellobiohydrolase (CBH), N-acetylglucosaminidase (NAG) and acid phosphatase (AP) under different land use types and pH gradients of tea garden soils. The results revealed that natural forest and cropland soils had significantly higher BG and CBH activities than tea garden soils. Soil BG and CBH activities displayed significant positive correlations with soil pH, total nitrogen (TN) and phosphorus (TP), while soil NAG activity was significantly associated with nitrate nitrogen, total carbon (TC), TN, carbon: phosphorus (C:P) and nitrogen: phosphorus (N:P) ratios. Soil AP activity showed significant negative associations with pH, TP and C:N ratio, but was significantly positively correlated with TC, TN, C:P and N:P ratios. Enzyme vector model revealed that soil microorganisms are limited by P (enzyme vector angle >45°) regardless of land use types. Compared to natural forest soils, the P limitation of microorganisms in tea garden soils became increasingly serious with a decreasing pH gradient, as indicated by the significant increase in enzyme vector angle. Thus, the overall ecoenzymatic stoichiometry was shifted by soil pH. In summary, higher pH increased BG activity and decreased AP activity, but had no significant effect on NAG activity, suggesting co-limitation of soil microorganisms by C and P in this area. This study provides novel insights into the effect of soil acidification on ecoenzymatic stoichiometry, and also highlights the stoichiometric and energy limitations on the metabolism of soil microorganisms in agricultural ecosystems.