Acid Phosphatase Enzyme Activity Research Articles

The impact on Cd bioavailability and accumulation in rice (Oryza sativa L.) induced by dry direct-seeding cultivation method in field-scale experiments

Dry direct-seeded rice cultivation has gained popularity and expanded its cultivated area due to reduced labor requirements and water consumption. However, the impact of this cultivation method on cadmium (Cd) bioavailability in soil and the accumulation levels in grains remains uncertain. Field experiments were conducted in acidic soils at two locations in southern China to compare rice varieties and evaluate the dry direct-seeding method alongside the wet direct-seeding and traditional transplanting methods. Dry direct-seeded rice reached significantly higher Cd concentrations in its tissues starting from the heading stage than transplanted rice. Cd accumulation levels by the maturation stage in the brown rice of dry direct-seeded rice were 18.33 %–150.69 % higher than those of wet direct-seeded and transplanted rice, with a considerable ability to translocate Cd into brown rice. Furthermore, dry direct seeding decreased iron plaque formation, particularly in the amorphous Fe form; it resulted in high soil temperature and low moisture content during tillering, elevating Cd availability in the soil. Additionally, the proportion of ions and more labile forms of Cd in the soil solution was high. Moreover, the soil under dry direct seeding had high urease and acid phosphatase enzyme activities. However, low richness and diversity in the bacterial community were characterized by a significant increase in the relative abundance of Actinobacteria and Gammaproteobacteria at the class level, while exhibiting decreased relative abundances of Alphaproteobacteria, Bacilli, and KD4-96, along with fewer biomarkers. Nonetheless, these differences are gradually reduced during the maturation stage. Overall, although dry direct seeding offers several advantages, it is crucial to implement additional measures to mitigate the increased health risks linked to rice cultivation through this approach in Cd-contaminated areas.

Effect of Chitosan Degradation Products, Glucosamine and Chitosan Oligosaccharide, on Osteoclastic Differentiation.

Chitosan, a natural cationic polysaccharide derived from crustaceans and shellfish shells, is known for its advantageous biological properties, including biodegradability, biocompatibility, and antibacterial activity. Chitosan and its composite materials are studied for their potential for bone tissue repair. However, the effects of chitosan degradation products, glucosamine (GlcN) and chitosan oligosaccharide (COS), on osteoclasts remain unclear. If these chitosan degradation products promote osteoclastic differentiation, careful consideration is required for the use of chitosan and related materials in bone repair applications. Here, we assessed the effects of high (500 μg/mL) and low (0.5 μg/mL) concentrations of GlcN and COS on osteoclastic differentiation in human peripheral blood mononuclear cells (PBMCs) and murine macrophage-like RAW264 cells. A tartrate-resistant acid phosphatase (TRAP) enzyme activity assay, TRAP staining, and actin staining were used to assess osteoclastic differentiation. High concentrations of GlcN and COS, but not low concentrations, suppressed macrophage colony-stimulating factor (M-CSF)- and RANKL-dependent increases in TRAP enzyme activity, TRAP-positive multinuclear osteoclast formation, and actin ring formation in PBMCs without cytotoxicity. Similar effects were observed in the RANKL-dependent osteoclastic differentiation of RAW264 cells. In conclusion, chitosan degradation products do not possess osteoclast-inducing properties, suggesting that chitosan and its composite materials can be safely used for bone tissue repair.

Soil properties and quinoa yield as affected by irrigation and vermicompost application under a drip-tape irrigation system

IntroductionQuinoa a crop with high nutritional value has the widespread adaptability to different climates and there is an increased demand for this product in the world. Characterized by roots with extensive penetration capabilities and wide, alternate leaves giving rise to diverse inflorescences, quinoa plants exhibit variable heights ranging from 20 to 300 cm. The duration of their growth phase spans 95 to 125 days’ contingent upon cultivar selection and prevailing climatic conditions.Materials and methodsIn order to reduce chemical fertilizers consumption through using organic fertilizers a two-year study was conducted at the Research Farm of the University of Kurdistan, Iran, during the 2021–2022 growing seasons. In this study the effects of varying levels of irrigation and vermicompost application on soil characteristics and quinoa (Chenopodium quinoa) yield were investigated. The experiments were arranged as split plots within a randomized complete block design. The main factor consisted of four irrigation levels (50%, 75%, 100%, and 125% of quinoa’s water requirement), while the sub-factor encompassed four vermicompost application rates (0, 5, 10, and 15 tons per hectare). The irrigation method employed was a drip-tape irrigation system with a seven-day interval between irrigations, and water quantities were measured using a volumetric meter on the main pipeline.ResultsThe results demonstrated that the highest levels of available soil phosphorus (21.83 mg kg−1) and soil ammonium (36.08 mg kg−1) were observed in the treatment receiving 50% of quinoa’s water requirement combined with 15 tons per hectare of vermicompost. Additionally, the application of 15 tons per hectare of vermicompost led to the highest concentrations of soil nitrate (14.16 mg kg−1), available potassium (144.62 mg kg−1), and quinoa seed yield (1784.01 kg ha−1)). Over both years, the greatest activity of alkaline and acid phosphatase enzymes was noted in the treatment receiving 125% of quinoa’s water requirement in combination with 15 tons per hectare of vermicompost. Vermicompost application was found to enhance yield and ameliorate drought stress by enhancing soil physical and chemical properties and improving soil moisture retention.

Effects of Photoperiod on Survival, Growth, Physiological, and Biochemical Indices of Redclaw Crayfish (Cherax quadricarinatus) Juveniles

Through a 30-day experiment, this study investigated the effects of five photoperiods (0L:24D, 6L:18D, 12L:12D, 18L:6D, and 24L:0D) on the survival, enzyme activity, body color, and growth-related gene expression of redclaw crayfish (Cherax quadricarinatus) juveniles. The results showed that C. quadricarinatus juveniles under 18L:6D and 24L:0D photoperiods exhibited the highest survival rate, which was significantly higher than the survival rates of juveniles under the other three photoperiods (p < 0.05). However, the 0L:24D group had the highest final body weight and weight gain rate, significantly surpassing those of the 12L:12D, 18L:6D, and 24L:0D groups (p < 0.05). Regarding enzyme activity and hormone levels, juveniles under the 18L:6D photoperiod exhibited relatively higher activity of superoxide dismutase (SOD), acid phosphatase (ACP), and lysozyme (LZM) enzymes than those under other photoperiods, but their levels of melatonin and cortisol were relatively low. In addition, the 24L:0D group showed the highest malondialdehyde (MDA) content. Analysis of gene expression levels revealed that retinoid X receptor (RXR) and α-amylase (α-AMY) genes in C. quadricarinatus juveniles exhibited significantly higher expression levels under the 18L:6D photoperiod than those under the other four photoperiods (p < 0.05). With increasing daylight exposure, the body color of C. quadricarinatus changed from pale blue to yellow–brown. In summary, C. quadricarinatus juveniles achieved high survival rates, good growth performance, strong antioxidant stress response, and immune defense capabilities under an 18 h photoperiod. Therefore, in the industrial seedling cultivation of redclaw crayfish, it is recommended to provide 18 h of daily light. Further, the study demonstrated the ability to manipulate the body color of C. quadricarinatus through controlled artificial photoperiods. These findings provide essential technical parameters needed for the industrial cultivation of C. quadricarinatus juveniles.

Investigating the toxic effects of ethoprophos on Eisenia fetida: Integrating light microscopy, scanning electron microscopy, and biochemical analysis

This research investigated the ecological impact of exposing Eisenia fetida, an essential component of soil ecosystems, to the organophosphate pesticide ethoprophos, widely used in agriculture. With a focus on understanding the specific effects on earthworms, we employed three concentrations (7.5, 15, and 30 mg/kg) over 28 days, considering the pesticide's short half-life and existing data on environmental concentrations. We aimed to contribute to a broader understanding of how these pesticides affect soil health. Histological analysis, including staining with Hematoxylin-eosin, Mallory Trichrome, Periodic acid-Schiff, and Alcian blue methods, was conducted on control and treatment groups. The histological and histopathological results were evaluated using the light microscopy, revealing various degenerations in the epithelial and muscle layers. Scanning electron microscopy analysis detected concentration-related notable compaction of the body surface, asymmetry, and distortion in the body segments. In the exposed groups, especially those subjected to higher ethoprophos concentrations, the grid-like appearance of the clitellum was visibly disturbed. This disturbance in the grid-like pattern is indicative of structural changes and disruptions at the microscopic level. Furthermore, total protein, carbohydrate, lipid analyses, as well as acid phosphatase and alkaline phosphatase enzyme activities, were also evaluated for earthworms from each experimental group. The analyses showed a concentration-related decrease in all biochemical measurements, except acid phosphatase enzyme activity. In conclusion, our study reveals that the environmentally realistic concentrations of ethoprophos, an effective and widely used pesticide in pest control, have detrimental effects on the health and physiology of E. fetida. These effects are manifested through histological deformities, altered biochemical profiles, and observable physiological disturbances. These results shed light on the harmful effects of ethoprophos on earthworms, underlining the necessity to restrict its usage in agricultural practices and thereby support environmental sustainability.

Comparative physiological and transcriptomic analysis of two salt-tolerant soybean germplasms response to low phosphorus stress: role of phosphorus uptake and antioxidant capacity

BackgroundPhosphorus (P) and salt stress are common abiotic stressors that limit crop growth and development, but the response mechanism of soybean to low phosphorus (LP) and salt (S) combined stress remains unclear.ResultsIn this study, two soybean germplasms with similar salt tolerance but contrasting P-efficiency, A74 (salt-tolerant and P-efficient) and A6 (salt-tolerant and P-inefficient), were selected as materials. By combining physiochemical and transcriptional analysis, we aimed to elucidate the mechanism by which soybean maintains high P-efficiency under salt stress. In total, 14,075 differentially expressed genes were identified through pairwise comparison. PageMan analysis subsequently revealed several significantly enriched categories in the LP vs. control (CK) or low phosphorus + salt (LPS) vs. S comparative combination when compared to A6, in the case of A74. These categories included genes involved in mitochondrial electron transport, secondary metabolism, stress, misc, transcription factors and transport. Additionally, weighted correlation network analysis identified two modules that were highly correlated with acid phosphatase and antioxidant enzyme activity. Citrate synthase gene (CS), acyl-coenzyme A oxidase4 gene (ACX), cytokinin dehydrogenase 7 gene (CKXs), and two-component response regulator ARR2 gene (ARR2) were identified as the most central hub genes in these two modules.ConclusionIn summary, we have pinpointed the gene categories responsible for the LP response variations between the two salt-tolerant germplasms, which are mainly related to antioxidant, and P uptake process. Further, the discovery of the hub genes layed the foundation for further exploration of the molecular mechanism of salt-tolerant and P-efficient in soybean.

Оценка применимости почвогрунтов, произведённых из твёрдых отходов для выращивания лекарственных растений

The production of artificial soils – products of solid-phase fermentation of municipal solid waste – is one of the main areas of processing waste from megacities containing organic substances and is a “green” alternative to their incineration or burial. The possibility of using products of solid-phase fermentation of waste for growing medicinal plants was studied using the examples of mountain savory (Satureja montana L.), common basil (Ocimum basilikum L.), marshmallow (Althaea officinalis L.), oregano (Origanum vulgare L.). It was revealed that the optimal germination of plants occurs on the artificial soils “Klasmann Substrates Select” and “Grunt ECO” and it is comparable to the control soil of field crop rotation.The changes in the biochemical parameters of plants (enzyme activity, chlorophyll content) grown on soils under normal conditions, under the influence of heavy metals and at low temperatures are shown. High chlorophyll content was noted in all studied plants, however, in mountain savory grown on the “Veltorf” substrate, destructive phenomena were revealed, expressed in a decrease in the content of chlorophyll a with a simultaneous increase in the content of chlorophyll b. The activity of catalase and acid phosphatase enzymes in the studied plants is within normal limits. The effect of unfavorable factors – low temperature and heavy metals – leads to an increase in enzyme activity, which is a sign of the formation of adaptation. When assessing the germination of plants of various species and their biochemical parameters, it was found that the domestic soil of the Grunt ECO company is optimal for growing medicinal plants and can be used for medicinal plant growing purposes.

Effects of natural and prolonged crude oil pollution on soil enzyme activities

In this study the effects of natural and long-term oil pollution levels (H: high, M: moderate and L: low) on the activity of lipase, β-glucosidase, urease, phosphatase, and dehydrogenase were analyzed. For this purpose, 120 oil-contaminated soil samples were collected from four locations located in oil-rich region of the west of Iran (Kermanshah province, Iran). After determining the physicochemical characteristics of soils, microbial counting and enzyme activities were measured. To determine the total bacterial population and bacteria involved in crude oil decomposition, bacterial counting was done in NA and CFMM culture media, respectively, which had a direct relationship with the increase in crude oil content. The average percentage of crude oil measured by Soxhlet method was 4.03%, 9.95% and 22.50% respectively for L, M and H levels. The results showed that the bacterial population increased with the increase of the contamination intensity. All the studied enzymes, except urease, had the highest activity in heavily polluted soils (H soil), and their lowest activity was observed in lightly polluted soils (L soils). Location 1 had the highest bacterial population as well as the highest activity of dehydrogenase (52.13 μg TPFg−1 h−1), acid phosphatase (35.86 μg PNPg−1 h−1), alkaline phosphatase (78.13 μg PNPg−1 h−1), lipase (92.58 μ MLA g−1 h−1) and β-glucosidase (21.67 μg PNPg−1 h−1) enzymes. In the soil samples of location 4, which had the lowest number of bacteria, the highest activity of urease enzyme (592.36 μg NH4g−1 h−1) was obtained. Principal components analysis (PCA) was also performed and 67% of the cumulative of the samples could be explained by the first two components (biochemical and physical). The findings of this research showed that natural and prolonged crude oil pollution caused the selection of oil-resistant microbial communities, and therefore we saw their positive response to the presence of oil compounds and increased enzyme activity other than urease activity.

Machine learning prediction and interpretation of the impact of microplastics on soil properties

The annual microplastic (MP) release into soils is 4–23 times higher than that into oceans, significantly impacting soil quality. However, the mechanisms underlying how MPs impact soil properties remain largely unknown. Soil-MP interactions are complex because of soil heterogeneity and varying MP properties. This lack of understanding was exacerbated by the diverse experimental conditions and soil types used in this study. Predicting changes in soil properties in the presence of MPs is challenging, laborious, and time-consuming. To address these issues, machine learning was applied to fit datasets from peer-reviewed publications to predict and interpret how MPs influence soil properties, including pH, dissolved organic carbon (DOC), total P, NO3−-N, NH4+-N, and acid phosphatase enzyme activity (acid P). Among the developed models, the gradient boost regression (GBR) model showed the highest R2 (0.86–0.99) compared to the decision tree and random forest models. The GBR model interpretation showed that MP properties contributed more than 50% to altering the acid P and NO3−-N concentrations in soils, whereas they had a negligible impact on total P and 10–20% impact on soil pH, DOC, and NH4+-N. Specifically, the size of MPs was the dominant factor influencing acid P (89.3%), pH (71.6%), and DOC (44.5%) in soils. NO3−-N was mainly affected by the MP type (52.0%). The NH4+-N was mainly affected by the MP dose (46.8%). The quantitative insights into the impact of MPs on soil properties of this study could aid in understanding the roles of MPs in soil systems.

Soil Microbial Community and Their Relationship with Soil Properties across Various Landscapes in the Mu Us Desert

Soil microorganisms play crucial roles in maintaining material circulation and energy flow in desert ecosystems. However, the structure and function of soil microorganisms in different forestlands are currently unclear, restricting the use of sand-fixing plants and the understanding of forest ecosystem functions. In this study, Artemisia ordosica, Caragana korshinskii, and Salix psammophila, three types of sand-fixing forests widely distributed in the Mu Us Sandy Land, were used to explore the effects of sand-fixing forests on soil physicochemical properties, soil enzyme activity, soil microbial biomass, microbial community structure, and inter-microbial species relationships. Soils of forestlands showed higher soil organic carbon (SOC), total phosphorus (TP), and total nitrogen (TN) contents than bare sandy land. The SOC in bare sandy soil was only 0.84 g kg−1, while it remained 1.55–3.46 g kg−1 in forestland soils. The TN in bare sandy land soil was 0.07 g kg−1, which was significantly lower than that in forestland soils (0.35–0.51 g kg−1). The TP in bare sandy soil was 0.18 g kg−1, significantly lower than that in forestland soils (0.46–0.69 g kg−1). Afforestation of bare sandy land improved soil microbial carbon and nitrogen contents and increased microbial enzyme activities of acid phosphatase and N-acetyl-β-D-glucosaminidase. Significant differences were observed between the three forestlands and bare sandy land in terms of soil microorganisms and community composition. With the establishment of a sand-fixing forest, the alpha diversity of soil bacteria significantly improved, whereas that of soil fungi remained stable. The bacterial community comprised 33 phyla, 106 classes, 273 orders, 453 families, and 842 genera. While five fungal phyla were detected by OTUs at a similarity of 97%, bacterial and fungal community structures were affected by the organic carbon content, sand particle content, soil pH, total nitrogen, and total phosphorus contents of soils. This study is helpful for vegetation construction and protection on sandy lands from the perspective of plant-microbe interactions.

Enzyme activity, DNA degradation and drying times of semen, saliva and vaginal material

The stability of enzyme activity and the amount of detectable DNA within liquid samples of semen, saliva and vaginal material were tested across a number of days. The concentration of DNA within neat semen and saliva samples fell significantly after one week of refrigeration. No apparent change in acid phosphatase or amylase enzyme activity was observed in neat semen and saliva samples over 96 or 72 h respectively. Changes in the enzyme activity of most of the dilute semen and saliva samples, as well as the neat vaginal material sample, were noted after 24 h. The drying times and sizes of stains produced from various volumes of neat semen, saliva and vaginal material were tested on porous and non-porous surfaces at room temperature. Larger volumes of body fluid took longer to dry and generally resulted in larger stains. Body fluids on a non-porous surface took longer to dry than on the porous surface tested.

Iron-modified biochar improves plant physiology, soil nutritional status and mitigates Pb and Cd-hazard in wheat (Triticum aestivum L.).

Environmental quality and food safety is threatened by contamination of lead (Pb) and cadmium (Cd) heavy metals in agricultural soils. Therefore, it is necessary to develop effective techniques for remediation of such soils. In this study, we prepared iron-modified biochar (Fe-BC) which combines the unique characteristics of pristine biochar (BC) and iron. The current study investigated the effect of pristine and iron modified biochar (Fe-BC) on the nutritional values of soil and on the reduction of Pb and Cd toxicity in wheat plants (Triticum aestivum L.). The findings of present study exhibited that 2% Fe-BC treatments significantly increased the dry weights of roots, shoots, husk and grains by 148.2, 53.2, 64.2 and 148%, respectively compared to control plants. The 2% Fe-BC treatment also enhanced photosynthesis rate, transpiration rate, stomatal conductance, intercellular CO2, chlorophyll a and b contents, by 43.2, 88.4, 24.9, 32.5, 21.4, and 26.7%, respectively. Moreover, 2% Fe-BC treatment suppressed the oxidative stress in wheat plants by increasing superoxide dismutase (SOD) and catalase (CAT) by 62.4 and 69.2%, respectively. The results showed that 2% Fe-BC treatment significantly lowered Cd levels in wheat roots, shoots, husk, and grains by 23.7, 44.5, 33.2, and 76.3%. Whereas, Pb concentrations in wheat roots, shoots, husk, and grains decreased by 46.4, 49.4, 53.6, and 68.3%, respectively. Post-harvest soil analysis showed that soil treatment with 2% Fe-BC increased soil urease, CAT and acid phosphatase enzyme activities by 48.4, 74.4 and 117.3%, respectively. Similarly, 2% Fe-BC treatment significantly improved nutrients availability in the soil as the available N, P, K, and Fe contents increased by 22, 25, 7.3, and 13.3%, respectively. Fe-BC is a viable solution for the remediation of hazardous Cd and Pb contaminated soils, and improvement of soil fertility status.

Impact of Foliar Application of Nano Nitrogen and Nano Zinc on Soil Properties of Mustard (Brassica juncea L.) Crop

The utilization of nano-sized nitrogen (N) and zinc (Zn) fertilizers through foliar application has gained considerable attention in agricultural research. This study focuses on investigating the effects of such foliar applications on soil properties, including both chemical and biological aspects, after the harvest of mustard (Brassica juncea L.). The field experiment was carried out during October to March 2022 season at Instructional Farm, Rajasthan College of Agriculture, MPUAT, Udaipur which lies in agro-climatic zone IV-A of Rajasthan, India. The field was designed in a randomized block design having 10 treatments which were replicated thrice. The treatments include the various combination RDF and nano fertilizers of N and Zn. The application treatment T6 (100% NPK Zn +1st spray of Nano N and Zn at 30 DAS +2nd spray of Nano N and Zn at 45 DAS) has significantly increased the availability of macronutrients (N, P, K), micronutrients (Zn, Fe, Cu and Mn), microbial population (bacteria, fungi and actinomycetes) as well as the dehydrogenase and acid phosphatase enzyme activity in post-harvest soil of mustard over control.

EFFECT OF PHYSICO-CHEMICAL POLLUTION OF RIVER DEORANIA ON THE METABOLIC ACTIVITIES OF PREDATORY FISH, CHANNA PUNCTATUS AT DISTRICT BAREILLY (U.P.) INDIA

The present study was aimed at assessing the value of different physicochemical parameters of two sites (i.e. site A is clear and considered a control site while site B is loaded with heavy pollution so it is considered as experimental site) during December 2005-2006 and 2020-2021 in extreme months of different seasons. The analysis showed that the discharge of a major part of domestic wastes of Bareilly City, city refuge, debris, animal and human excreta and industrial effluents, enhanced the pollution load at site B and thereby enhanced the abnormal metabolic activities of fish. Whereas at clear site A the metabolic activities of fish were normal. In the present study, the following parameters i.e. temperature, colour, transparency, dissolved oxygen (DO), free CO2, biochemical oxygen demand (BOD), salinity, total dissolved solids (TDS), level of glycogen, reducing sugar level, total protein level, level of amino acids, activity of alkaline phosphatase and acid phosphatase enzymes were analysed.

Comparative studies of conventional, organic and natural farming types for their efficiency, and productivity in maize + red gram intercropping system

The field experiment on comparative studies of different farming methods for their efficiency and productivity in maize + redgram intercropping system was conducted at zonal agricultural and horticultural research station, Bhavikere during Kharif season. Among the different farming types, growth and yield parameters of maize viz. plant height (204.18 cm) number of leaves/ plant (17.20), cob length (15.94cm), straw yield (19.35 t/ ha) grain yield (81.36 q/ ha) and red gram Grain yield (4.36 q/ ha) and straw yield (11.19 q/ ha) were significantly higher with treatment received nutrients as per package of practices as compared to natural farming and organic farming treatments. Similar trend was observed with maize equivalent yield (95.50 q/ ha). On the other hand, highest dehydrogenase (14.32, 28.65, 24.19 and 16.23 µg TPF/ g soil/ day) and urease (4.12, 12.65, 7.14 and 3.32 µg NH4-N/ g / soil/ 2 hrs) enzyme activity was observed in organic farming treatment at 30, 60, 90 DAS and at harvest, respectively followed by natural farming treatment and least enzyme activity was noticed in farmers practice. Same trend was observed in acid and alkaline phosphatase enzyme activities. There was no much variation in physical properties i.e., bulk density, particle density, maximum water holding capacity and porosity by the different treatments and also no significant difference occurs in the pH and EC, however higher nitrogen (315.27) phosphorus (73.48) and potassium (271.28) was observed in the organic farming treatment and it was followed with the farmer’s practice treatment. The lowest was recorded in the natural farming treatment (215.47, 33.47 and 220.47 at the harvest stage).

Impact of ryegrass cover crop inclusion on soil phosphorus and pqqC- and phoD-harboring bacterial communities

Italian ryegrass (Lolium multiflorum L.) is widely used as a cover crop with rice to promote soil fertility and reduce nutrient loss, although the specific impacts on phosphorus (P) dynamics and bioavailability are not clear. Soil samples were taken from a 4-year field experiment that included fertilized fallow-rice and ryegrass cover crop-rice rotations, together with an unfertilized fallow-rice control. Soil analyses included pH, total carbon (C) and nitrogen (N), together with soil P fractionations, acid and alkaline phosphatase enzyme activities, and assessment of the diversity and community of bacterial genes associated with inorganic P solubilization (pqqC) and organic P mineralization (phoD). Results showed that inclusion of the ryegrass cover crop enhanced biological P cycling in soil by significant increases in soil organic P and phosphatase enzyme activities compared with the fertilized fallow. The ryegrass cover crop was shown to reinforce the connection between soil P fractions and pqqC- and phoD-harboring bacterial communities, especially for the genus Rubrobacter. Cover crop inclusion also affected pqqC-harboring bacterial community composition by increasing the relative abundance of Actinobacteria, which reflected changes in the ratios of total P to total carbon and nitrogen in soil. In addition, the pqqC-harboring bacterial community was more affected by the ryegrass cover crop than the corresponding phoD-harboring community. The findings of this study demonstrated that the inclusion of ryegrass as a cover crop with rice significantly impacted biological P cycling in soil which may contribute to improved long-term P use efficiency.

Impact of nitrogen addition on single and mixed tree leaf litter decomposition depends on N forms in subtropical China

Increased nitrogen (N) inputs via atmospheric deposition are believed to influence leaf litter decomposition rate in forests. However, whether inorganic and organic N deposition produces a consistent influence on leaf litter decomposition is uncertain in forests, especially leaf litter mixtures. Using a fertilization experiment, we investigated the impact of inorganic (NH4Cl) and organic (urea and glycine) N on decomposition of single leaf litter (Liquidambar formosana, Pinus elliottii, Pinus massoniana, and Schima superba) and mixed broadleaf and coniferous (equal mass ratio) leaf litter using the litterbag method in a subtropical forest in southern China. Both inorganic and organic N addition increased mineral soil β-1,4-glucosidase, cellobiohydrolase, β-1,4-N-acetylglucosaminidase, L-leucine aminopeptidase, and acid phosphatase enzyme activities. During 780-day incubation, single litter decomposition was accelerated by NH4Cl addition but was not affected by either urea or glycine addition. Irrespective of added N forms, N addition shifted litter mixing effects on decomposition from synergistic effects to either additive or antagonistic effects. Accordingly, N addition generally decelerated litter mixture decomposition rates. Compared to coniferous litter, N addition-induced changes in litter mixing effects were often lower for broadleaf litter within the litter mixtures. These findings suggest that the impact of N enrichment on litter decomposition depends upon litter types and N forms, and highlight that N forms should be incorporated into assessing the consequence of atmospheric N deposition on the biogeochemical cycles in subtropical forests.

Effects of eutrophic water with ammonium chloride, urea, potassium dihydrogen phosphate and sodium-β-glycerophosphate on Myriophyllum verticillatum and epiphytic bacteria

With the rapid development of industry and agriculture, excessive nitrogen and phosphorus released into natural surface water have caused eutrophication. Applying submerged plants to manage eutrophic water has attracted widespread attention. However, there are limited studies on the effects of different nitrogen and phosphorus in the water environment on submerged plants and their epiphytic biofilm. Therefore, this paper investigated the effects of eutrophic water with ammonium chloride (IN), urea (ON), potassium dihydrogen phosphate (IP), and sodium-β-glycerophosphate (OP) on Myriophyllum verticillatum and epiphytic biofilms. The results showed that Myriophyllum verticillatum exhibited a good purification effect on the eutrophic water with inorganic phosphorus, the removal rates of IP were 68.0%, and the plants grew best in this condition. The fresh weight of the IN group and ON group increased by 12.24% and 7.12%, and the shoot length of the IN group and the ON group increased by 17.71% and 8.33%; the fresh weight of the IP group and OP group increased by 19.19% and 10.83%, the shoot length of the IP group and the OP group increased by 21.09% and 18.23%. In addition, the enzyme activities of superoxide dismutase, catalase, nitrate reductase, and acid phosphatase in plant leaves were significantly changed in eutrophic water with different forms of nitrogen and phosphorus. Finally, the analysis of the epiphytic bacteria showed that different forms of nitrogen and phosphorus nutrients could significantly alter the abundance and structure of microorganisms and microbial metabolism also had significant changes. This study provides a new theoretical basis for evaluating the removal of different forms of nitrogen and phosphorus by Myriophyllum verticillatum, and it also provides new insights for the subsequent engineering of epiphytic microorganisms to improve the capability of submerged plants to treat eutrophic water.

Clam challenges high concentrations of algae diet environment: Growth performance, metabolism physiology, and related gene expression characteristics

Increasing coastal pollution leads to frequent algal blooms, but little is known on the effect of growth and development in organisms with increasing algal concentration. In recent years, the clam Cyclina sinensis has been an important marine economic shellfish that is widely cultivated. This study investigated the effects of different Chlorella concentrations (5 × 105 cell/L (Diet T1), 1.25 × 106 cell/L (Diet T2), 1.3 × 107 cell/L (Diet T3), 1.25 × 108 cell/L (Diet T4), and 1.5 × 109 cell/L (Diet T5)) on the growth, enzyme activities of digestive, immune, and respiratory metabolism, and hepatopancreatic transcriptome gene expression characteristic response of C. sinensis. Results showed that the shell length growth rate, shell height growth rate, and survival rate of C. sinensis significantly decreased as the Chlorella concentration reached 5 × 105 cell/L. The condition factor of C. sinensis in Diet T1 and the hepatopancreas index of C. sinensis in Diet T4 were significantly higher than those in the other groups (P < 0.05). The enzyme activities of superoxide dismutase increased significantly with the rise in concentration of Chlorella, but the highest lysozyme in the hepatopancreas of C. sinensis was observed in the Diet T1 group. The enzyme activities of acid phosphatase and amylase in Diet T3, trypsin in Diet T5, lipase and succinate dehydrogenase in Diet T4, and lactate dehydrogenase in Diet T1 of C. sinensis were significantly higher than those in the other groups (P < 0.05). These results suggest that some enzyme activities related to digestion, metabolism, and respiration are inhibited with the Chlorella concentration increased. Furthermore, transcriptome results showed that the expression levels of G6P, IGFBP, CHI3L1, FAS, MyHC, and other genes related to glucose, protein, and fatty acid metabolism of C. sinensis were significantly downregulated in the Diet T3 and Diet T5 groups. All these results suggest that Chlorella concentrations above 5 × 105 cell/L should be avoided in practice. This study provides a scientific basis for C. sinensis culture and further extends the understanding of the metabolism of bivalves with diet concentration.

Response of Lime and Phosphorus Application on Groundnut Growth, Yield and Soil Enzyme Activities in Acidic Soil of North Eastern India

ABSTRACT Soils in the north east Indian region are acidic in nature due to high rainfall and proper soil management is required where the common deficiencies like P, Ca and Mg have to be alleviated for a successful groundnut production. To test the effect of lime and phosphorus on groundnut yield and soil health, we conducted a field experiment during kharif season of 2014 and 2015 in ICAR RC NEH, Mizoram center farm (soil pH 5.1) using three levels of lime (0, 500 and 1000 kg CaCO3 ha‒ 1) and phosphorus (0, 25 and 50 kg ha‒ 1). Pooled data of lime and P application significantly improved the plant height and dry matter production per plant. Lime application improved number of pods by 14.8% and 26.1%, weight of pods by 19% and 30%, test weight by 5%, 8.7%, shelling percentage by 6.1%, 13% and pod yield by 26.5% and 63%. Lime application significantly raised the soil pH from 5.17 to 5.26 (L500) and 5.4 (L1000), subsequently increasing available nutrients like N, P and K whereas P @ 50 kg ha‒ 1 improved the available P status. Lime application negatively affect acid phosphatase activity while increasing the activity alkaline phosphatase, arylsulphatase, β‒glucosidase and dehydrogenase by 14.4% and 21%, 4% and 21%, 18.25% and 20.4% and 43.2% while P application decrease the acid phosphatase enzyme activity by 3 and 4.4%. Overall, multivariate PCA analysis suggests that liming has a significant role in improving soil health and groundnut productivity in acidic soil of Mizoram.