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1.
Front Microbiol ; 15: 1367184, 2024.
Article in English | MEDLINE | ID: mdl-38827150

ABSTRACT

Diversifying cultivation management, including different crop rotation patterns and soil amendment, are effective strategies for alleviating the obstacles of continuous cropping in peanut (Arachis hypogaea L.). However, the peanut yield enhancement effect and temporal changes in soil chemical properties and microbial activities in response to differential multi-year crop rotation patterns and soil amendment remain unclear. In the present study, a multi-year localization experiment with the consecutive application of five different cultivation managements (including rotation with different crops under the presence or absence of external quicklime as soil amendment) was conducted to investigate the dynamic changes in peanut nutrient uptake and yield status, soil chemical property, microbial community composition and function. Peanut continuous cropping led to a reduction in peanut yield, while green manure-peanut rotation and wheat-maize-peanut rotation increased peanut yield by 40.59 and 81.95%, respectively. A combination of quicklime application increased yield by a further 28.76 and 24.34%. Alterations in cultivation management also strongly affected the soil pH, nutrient content, and composition and function of the microbial community. The fungal community was more sensitive than the bacterial community to cultivation pattern shift. Variation in bacterial community was mainly attributed to soil organic carbon, pH and calcium content, while variation in fungal community was more closely related to soil phosphorus content. Wheat-maize-peanut rotation combined with quicklime application effectively modifies the soil acidification environment, improves the soil fertility, reshapes the composition of beneficial and harmful microbial communities, thereby improving soil health, promoting peanut development, and alleviating peanut continuous cropping obstacles. We concluded that wheat-maize-peanut rotation in combination with quicklime application was the effective practice to improve the soil fertility and change the composition of potentially beneficial and pathogenic microbial communities in the soil, which is strongly beneficial for building a healthy soil micro-ecology, promoting the growth and development of peanut, and reducing the harm caused by continuous cropping obstacles to peanut.

2.
Front Bioeng Biotechnol ; 12: 1385032, 2024.
Article in English | MEDLINE | ID: mdl-38807647

ABSTRACT

The exploration of the next-generation small diameter vascular grafts (SDVGs) will never stop until they possess high biocompatibility and patency comparable to autologous native blood vessels. Integrating biocompatible electrospinning (ES) matrices with highly bioactive stem cells (SCs) provides a rational and promising solution. ES is a simple, fast, flexible and universal technology to prepare extracellular matrix-like fibrous scaffolds in large scale, while SCs are valuable, multifunctional and favorable seed cells with special characteristics for the emerging field of cell therapy and regenerative medicine. Both ES matrices and SCs are advanced resources with medical application prospects, and the combination may share their advantages to drive the overcoming of the long-lasting hurdles in SDVG field. In this review, the advances on SDVGs based on ES matrices and SCs (including pluripotent SCs, multipotent SCs, and unipotent SCs) are sorted out, and current challenges and future prospects are discussed.

3.
Plants (Basel) ; 13(6)2024 Mar 11.
Article in English | MEDLINE | ID: mdl-38592790

ABSTRACT

Soil compaction is one of the crucial factors that restrains the root respiration, energy metabolism and growth of peanut (Arachis hypogaea L.) due to hypoxia, which can be alleviated by ventilation. We therefore carried out a pot experiment with three treatments: no ventilation control (CK), (2) ventilation volumes at 1.2 (T1), and 1.5 (T2) times of the standard ventilation volume (2.02 L/pot). Compared to no-ventilation in compacted soil, ventilation T1 significantly increased total root length, root surface area, root volume and tips at the peanut anthesis stage (62 days after sowing), while T2 showed a negative impact on the above-mentioned root morphological characteristics. At the podding stage (S2, 95 days after sowing), both ventilation treatments improved root morphology, especially under T1. Compared to CK, both ventilation T1 and T2 decreased the activities of enzymes involving the anaerobic respiration, including root lactate dehydrogenase, pyruvate decarboxylase and alcohol dehydrogenase. The activities of antioxidant enzymes of root superoxide dismutase, peroxidase and catalase also decreased at S1, while superoxide dismutase and peroxidase significantly increased under T1 at S2. The ventilation of compacted soil changed soil nitrogen-fixing bacterial communities, with highest bacterial alpha diversity indices under T1. The Pearson correlation analyses indicated a positive relationship between the relative abundance of Bradyrhizobiaceae and root activity, and between unclassified_family of Rhizobiales and the root surface area, while Enterobacteriaceae had a negative impact on the root nodule number. The Pearson correlation test showed that the root surface, tips and activity positively correlated with root superoxide dismutase and peroxidase activities. These results demonstrate that soil ventilation could enhance plant root growth, the diversity and function of soil nitrogen-fixing bacterial communities. The generated results from this present study could serve as important evidence in alleviating soil hypoxia caused by compaction.

4.
Polymers (Basel) ; 16(8)2024 Apr 10.
Article in English | MEDLINE | ID: mdl-38674960

ABSTRACT

This study aims to improve the slow-release performance of a film material for a controlled-release fertilizer (CRF) while enhancing its biodegradability. A water-based biodegradable polymer material doped with biochar (BC) was prepared from modified polyvinyl alcohol (PVA) with polyvinylpyrrolidone (PVP) and chitosan (CTS), hereinafter referred to as PVA/PVP-CTSaBCb. An environmentally friendly novel controlled-release phosphate fertilizer (CRPF) was developed using PVA/PVP-CTS8%BC7% as the film. The effect of the PVA/PVP-CTS8%BC7% coating on the service life of the CRPF was investigated. The film was characterized via stress-strain testing, SEM, FTIR, XRD, and TGA analyses. The addition of the CTS modifier increased the stress of PVA/PVP-CTS8% by 7.6% compared with that of PVA/PVP owing to the decrease in the crystallinity of PVP/PVP-CTS8%. The hydrophilic -OH groups were reduced due to the mixing of CTS and PVA/PVP. Meanwhile, the water resistance of the PVA/PVP-CTS8%BC7% was improved. And the controlled-release service life of the CRPF was prolonged. Moreover, the addition of BC increased the crystallinity of the PVA/PVP-CTS8% by 10%, reduced the fracture elongation of the material, and further improved the biodegradability of the PVA/PVP-CTS8%BC7%. When the amount of BC added was 7%, the phosphorus release rate of the CRPF was 30% on the 28th day. Moreover, the degradation rate of the PVA/PVP-CTS8%BC7% polymer film was 35% after 120 days. This study provides basic data for applying water-based degradable polymer materials in CRFs.

5.
Ecotoxicol Environ Saf ; 271: 115935, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38211514

ABSTRACT

The accumulation of microplastics in agricultural soil brings unexpected adverse effects on crop growth and soil quality, which is threatening the sustainability of agriculture. Biochar is an emerging soil amendment material of interest as it can remediate soil pollutants. However, the mechanisms underlying biochar alleviated the toxic effects of microplastics in crops and soil were largely unknown. Using a common economic crop, peanut as targeted species, the present study evaluated the plant physiologica and molecular response and rhizosphere microbiome when facing microplastic contamination and biochar amendment. Transcriptome and microbiome analyses were conducted on peanut root and rhizosphere soil treated with CK (no microplastic and no biochar addition), MP (1.5% polystyrene microplastic addition) and MB (1.5% polystyrene microplastic+2% peanut shell biochar addition). The results indicated that microplastics had inhibitory effects on plant root development and rhizosphere bacterial diversity and function. However, biochar application could significantly promote the expressions of key genes associated with antioxidant activities, lignin synthesis, nitrogen transport and energy metabolism to alleviate the reactive oxygen species stress, root structure damage, nutrient transport limitation, and energy metabolism inhibition induced by microplastic contamination on the root. In addition, the peanut rhizosphere microbiome results showed that biochar application could restore the diversity and richness of microbial communities inhibited by microplastic contamination and promote nutrient availability of rhizosphere soil by regulating the abundance of nitrogen cycling-related and organic matter decomposition-related microbial communities. Consequently, the application of biochar could enhance root development by promoting oxidative stress resistance, nitrogen transport and energy metabolism and benefit the rhizosphere microecological environment for root development, thereby improved the plant-soil system health of microplastic-contaminated agroecosystem.


Subject(s)
Microplastics , Soil , Soil/chemistry , Microplastics/toxicity , Plastics , Rhizosphere , Polystyrenes , Charcoal/pharmacology , Arachis , Nitrogen/analysis , Soil Microbiology
6.
J Sci Food Agric ; 104(5): 2990-3001, 2024 Mar 30.
Article in English | MEDLINE | ID: mdl-38050830

ABSTRACT

BACKGROUND: The accumulation of microplastics in agricultural soil poses a threat to the sustainability of agriculture, impacting crop growth and soil health. Due to the geocarpy feature of peanut, geocarposphere soil environment is critical to pod development and its nutritional quality. While the effects of microplastics in the rhizosphere have been studied, their impact on peanut pod in the geocarposphere remains unknown. Biochar has emerged as a potential soil agent with the ability to remediate soil contamination. However, the mechanisms of biochar in mitigating the toxic effects of microplastics-contaminated geocarposphere soil on peanut pod development remain largely unexplored. RESULTS: We evaluated the peanut pod performance and microbiome when facing microplastics contamination and biochar amendment in geocarposphere soil. The results showed that microplastics present in geocarposphere soil could directly enter the peanut pod, cause pod developmental disorder and exert adverse effects on nutritional quality. Aberrant expression of key genes associated with amino acid metabolism, lipid synthesis, and auxin and ethylene signaling pathways were the underlying molecular mechanisms of microplastics-induced peanut pod developmental inhibition. However, these expression abnormalities could be reversed by biochar application. In addition, peanut geocarposphere microbiome results showed that biochar application could restore the diversity of microbial communities inhibited by microplastics contamination and promote the relative abundance of bacteria correlated with pathogen resistance and nitrogen cycle of geocarposphere soil, further promoting peanut pod development. CONCLUSION: This study demonstrated that biochar application is an effective strategy to mitigate the toxic effects of microplastics-contaminated geocarposphere soil on pod development and nutritional quality. © 2023 Society of Chemical Industry.


Subject(s)
Arachis , Soil , Arachis/chemistry , Soil/chemistry , Microplastics/metabolism , Plastics , Charcoal/metabolism
7.
Antioxid Redox Signal ; 40(1-3): 168-185, 2024 01.
Article in English | MEDLINE | ID: mdl-37917094

ABSTRACT

Significance: Gasotransmitters are small gas molecules that are endogenously generated and have well-defined physiological functions. The most well-defined gasotransmitters currently are nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H2S), while other potent gasotransmitters include ammonia, methane, cyanide, hydrogen gas, and sulfur dioxide. Gasotransmitters play a role in various respiratory diseases such as asthma, chronic obstructive pulmonary disease, obstructive sleep apnea, lung infection, bronchiectasis, cystic fibrosis, primary ciliary dyskinesia, and COVID-19. Recent Advances: Gasotransmitters can act as biomarkers that facilitate disease diagnosis, indicate disease severity, predict disease exacerbation, and evaluate disease outcomes. They also have cell-protective properties, and many studies have been conducted to explore their pharmacological applications. Innovative drug donors and drug delivery methods have been invented to amplify their therapeutic effects. Critical Issues: In this article, we briefly reviewed the physiological and pathophysiological functions of some gasotransmitters in the respiratory system, the progress in detecting exhaled gasotransmitters, as well as innovative drugs derived from these molecules. Future Directions: The current challenge for gasotransmitter research includes further exploring their physiological and pathological functions, clarifying their complicated interactions, exploring suitable drug donors and delivery devices, and characterizing new members of gasotransmitters. Antioxid. Redox Signal. 40, 168-185.


Subject(s)
Gasotransmitters , Hydrogen Sulfide , Respiratory Tract Diseases , Humans , Hydrogen Sulfide/therapeutic use , Hydrogen Sulfide/pharmacology , Nitric Oxide , Carbon Monoxide , Respiratory Tract Diseases/diagnosis , Respiratory Tract Diseases/drug therapy
8.
BMC Plant Biol ; 22(1): 524, 2022 Nov 14.
Article in English | MEDLINE | ID: mdl-36372886

ABSTRACT

BACKGROUND: Phosphorus (P) is one of the most essential macronutrients for crops. The growth and yield of peanut (Arachis hypogaea L.) are always limited by P deficiency. However, the transcriptional and metabolic regulatory mechanisms were less studied. In this study, valuable phenotype, transcriptome and metabolome data were analyzed to illustrate the regulatory mechanisms of peanut under P deficiency stress. RESULT: In present study, two treatments of P level in deficiency with no P application (-P) and in sufficiency with 0.6 mM P application (+ P) were used to investigate the response of peanut on morphology, physiology, transcriptome, microRNAs (miRNAs), and metabolome characterizations. The growth and development of plants were significantly inhibited under -P treatment. A total of 6088 differentially expressed genes (DEGs) were identified including several transcription factor family genes, phosphate transporter genes, hormone metabolism related genes and antioxidant enzyme related genes that highly related to P deficiency stress. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses indicated that 117 genes were annotated in the phenylpropanoid biosynthesis pathway under P deficiency stress. A total of 6 miRNAs have been identified significantly differential expression between + P and -P group by high-throughput sequencing of miRNAs, including two up-regulated miRNAs (ahy-miR160-5p and ahy-miR3518) and four down-regulated miRNAs (ahy-miR408-5p, ahy-miR408-3p, ahy-miR398, and ahy-miR3515). Further, the predicted 22 target genes for 6 miRNAs and cis-elements in 2000 bp promoter region of miRNA genes were analyzed. A total of 439 differentially accumulated metabolites (DAMs) showed obviously differences in two experimental conditions. CONCLUSIONS: According to the result of transcripome and metabolome analyses, we can draw a conclusion that by increasing the content of lignin, amino acids, and levan combining with decreasing the content of LPC, cell reduced permeability, maintained stability, raised the antioxidant capacity, and increased the P uptake in struggling for survival under P deficiency stress.


Subject(s)
Arachis , MicroRNAs , Arachis/genetics , Arachis/metabolism , Transcriptome , Phosphorus/metabolism , Antioxidants/metabolism , MicroRNAs/genetics , MicroRNAs/metabolism , Metabolome , Phenotype , Gene Expression Profiling
9.
Front Plant Sci ; 13: 948742, 2022.
Article in English | MEDLINE | ID: mdl-36247623

ABSTRACT

Peanut (Arachis hypogaea L.) is an important oil crop globally because of its high edible and economic value. However, its yield and quality are often restricted by certain soil factors, especially nitrogen (N) deficiency, and soil compaction. To explore the molecular mechanisms and metabolic basis behind the peanut response to N deficiency and soil compaction stresses, transcriptome and metabolome analyses of peanut root were carried out. The results showed that N deficiency and soil compaction stresses clearly impaired the growth and development of peanut's aboveground and underground parts, as well as its root nodulation. A total of 18645 differentially expressed genes (DEGs) and 875 known differentially accumulated metabolites (DAMs) were identified in peanut root under differing soil compaction and N conditions. The transcriptome analysis revealed that DEGs related to N deficiency were mainly enriched in "amino acid metabolism", "starch and sucrose metabolism", and "TCA cycle" pathways, while DEGs related to soil compaction were mainly enriched in "oxidoreductase activity", "lipids metabolism", and "isoflavonoid biosynthesis" pathways. The metabolome analysis also showed significant differences in the accumulation of metabolisms in these pathways under different stress conditions. Then the involvement of genes and metabolites in pathways of "amino acid metabolism", "TCA cycle", "lipids metabolism", and "isoflavonoid biosynthesis" under different soil compaction and N deficiency stresses were well discussed. This integrated transcriptome and metabolome analysis study enhances our mechanistic knowledge of how peanut plants respond to N deficiency and soil compaction stresses. Moreover, it provides new leads to further investigate candidate functional genes and metabolic pathways for use in improving the adaptability of peanut to abiotic stress and accelerating its breeding process of new stress-resistant varieties.

10.
Neuroscience ; 413: 206-218, 2019 08 10.
Article in English | MEDLINE | ID: mdl-31220544

ABSTRACT

Accumulating evidence indicates that phosphorylated serum- and glucocorticoid-regulated kinase 1 (SGK1) is associated with spinal nociceptive sensitization by modulating glutamatergic N-methyl-D-aspartate receptors (NMDARs). In this study, we determined whether spinal SGK1 signaling contributes to the development of morphine analgesic tolerance. Chronic morphine administration markedly induced phosphorylation of SGK1 in the spinal dorsal horn neurons. Intrathecal injection of SGK1 inhibitor GSK-650394 reduced the development of morphine tolerance with a significant leftward shift in morphine dose-effect curve. Furthermore, spinal inhibition of SGK1 suppressed morphine-induced phosphorylation of nuclear factor kappa B (NF-κB) p65 and upregulation of NMDAR NR1 and NR2B expression in the spinal dorsal horn. In contrast, intrathecal administration of NMDAR antagonist MK-801 had no effect on the phosphorylation of SGK1 in morphine-treated rats. In addition, morphine-induced upregulation of NR2B, but not NR1, was significantly abolished by intrathecal pretreatment with PDTC, a specific NF-κB activation inhibitor. Finally, spinal delivery of SGK1 small interfering RNA exhibited similar inhibitory effects on morphine-induced tolerance, phosphorylation of NF-κB p65, as well as upregulation of NR1 and NR2B expression. Our findings demonstrate that spinal SGK1 contributes to the development of morphine tolerance by enhancing NF-κB p65/NMDAR signaling. Interfering spinal SGK1 signaling pathway could be a potential strategy for prevention of morphine tolerance in chronic pain management.


Subject(s)
Analgesics, Opioid/adverse effects , Drug Tolerance/physiology , Immediate-Early Proteins/metabolism , Morphine/adverse effects , Protein Serine-Threonine Kinases/metabolism , Analgesics, Opioid/pharmacology , Animals , Immediate-Early Proteins/antagonists & inhibitors , Male , Morphine/pharmacology , Neuronal Plasticity , Nociceptive Pain/drug therapy , Nociceptive Pain/metabolism , Phosphorylation/drug effects , Posterior Horn Cells/drug effects , Posterior Horn Cells/metabolism , Protein Serine-Threonine Kinases/antagonists & inhibitors , Random Allocation , Rats, Sprague-Dawley , Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors , Receptors, N-Methyl-D-Aspartate/metabolism , Signal Transduction/drug effects , Transcription Factor RelA/metabolism
11.
Ying Yong Sheng Tai Xue Bao ; 30(3): 961-968, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30912389

ABSTRACT

Root nodules in peanut (Arachis hypogaea L.) could directly utilize nitrogen (N) in the atmosphere as N source, which plays an important role in the N supply in peanut. However, little is known about the mechanism of efficient N fixation by root nodule. In this study, 15N tracer technology was used to investigate the characteristics of N fixation by root nodule and its relationship with peanut yields of 19 varieties in a pot culture experiment. Results showed that there were significant differences in nodule number, fresh quality, internal material, N fixation amount and other related indices among different varieties. The range of number and fresh mass of root nodule was 170.59-696.15 per pot and 0.83-3.74 g per pot, with coefficients of variation (CV) of 36.1% and 41.1%, respectively. The range of leghaemoglobin content and nitrogenase activity was 15.51-23.23 mg per pot and 2.75-20.46 µmol C2H4·h-1 per pot, with CV of 13.1% and 57.2%, respectively. The CV of nitrogenase activity was significantly higher than that of leghaemoglobin content, indicating that nitrogenase activity was not only affected by leghaemoglobin content but also other factors. The range of N fixation by root nodule and total N accumulation was 0.71-1.82 and 2.16-3.72 g per pot, with CV of 21.6% and 12.9%, respectively. The CV of the former was significantly higher than that of the latter, indicating that other N sources could automatically compensate the deficit when N fixation of root nodule was insufficient. Nitrogen fixation by root nodule was one of the main N sources for peanut, while the average N supply percentage was more than 40% of the total N, with a maximum of 50%. Cultivating the variety with high N supply capacity is an effective way for N-saving cultivation in the peanut production. Except for nodule number, there were significantly positive correlations between the other indices and peanut yield, indicating that the physiological indicators of N fixation were closely related to N fixation capacity by root nodule and the final yield. Therefore, enhancing these characters would help achieve high yield of peanut and simultaneously reduce fertilizer application.


Subject(s)
Fabaceae , Nitrogen Fixation , Arachis , Fertilizers , Nitrogen
12.
J Cardiothorac Vasc Anesth ; 31(6): 2086-2092, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28803772

ABSTRACT

OBJECTIVES: To evaluate whether perioperative statins reduce the risk of acute kidney injury (AKI) after cardiac surgery. DESIGN: Systematic review and meta-analysis of randomized trials. SETTING: Perioperative management in hospitals that perform cardiac surgery. PARTICIPANTS: Adult patients undergoing cardiac surgery. INTERVENTIONS: PubMed, EMBASE, and the Cochrane Library databases were searched for randomized trials. Random-effects meta-analyses were performed to compare the effects of statins versus placebo/control. Trial sequential analysis was conducted to confirm the results. MEASUREMENTS AND MAIN RESULTS: The primary outcome was incidence of postoperative AKI. Eight trials enrolling 3,204 patients were included. The statin arms and the control arms were comparable in incidence of postoperative AKI (risk ratio [RR] = 1.02, 95% confidence interval [CI] = 0.82-1.28), need for renal replacement therapy (RR = 1.09, 95% CI = 0.45-2.66), mechanical ventilation duration (mean difference [MD] = 24.84 min, 95% CI = -55.53-105.20), intensive care unit length of stay (MD = 0.04 days, 95% CI = -3.13-3.20), hospital length of stay (MD = -0.08 days, 95% CI = -0.31-0.15), and in-hospital mortality (RR = 3.76, 95% CI = 0.93-15.14). Trial sequential analysis confirmed that it is unlikely that perioperative statin therapy could achieve a 20% or more relative risk reduction in AKI incidence. CONCLUSIONS: Among patients undergoing cardiac surgery, perioperative statin treatment did not reduce the risk of AKI. Statin therapy should not be initiated to prevent AKI following cardiac surgery.


Subject(s)
Acute Kidney Injury/prevention & control , Cardiac Surgical Procedures/adverse effects , Hydroxymethylglutaryl-CoA Reductase Inhibitors/administration & dosage , Perioperative Care/methods , Postoperative Complications/prevention & control , Randomized Controlled Trials as Topic , Acute Kidney Injury/diagnosis , Acute Kidney Injury/epidemiology , Cardiac Surgical Procedures/trends , Humans , Perioperative Care/trends , Postoperative Complications/diagnosis , Postoperative Complications/epidemiology , Randomized Controlled Trials as Topic/methods , Risk Factors
13.
Sci Rep ; 6: 38629, 2016 12 09.
Article in English | MEDLINE | ID: mdl-27934905

ABSTRACT

Tillage intensities largely affect soil compaction dynamics in agro-ecosystems. However, the contribution of tillage intensities on compaction changes in underground peanut (Arachis hypogaea) fields has not been quantified. We thus aimed to better understand the role of soil tillage intensities in mitigation of compaction stress for peanuts. Using three field tillage experiments in major Chinese peanut producing areas, we quantified the effects of (1) no tillage, (2) shallow (20 cm) plowing, (3) deep (30 cm) plowing and (4) deep (30 cm) loosening on changes in soil bulk density at 0-10 cm, 10-20 cm and 20-30 cm depths, roots and pods growth, and nutrient accumulation. Results showed that tillage management effectively mitigated soil compaction stress for peanut growth and production. Greater beneficial improvement for the underground growth of roots and pods, and N accumulation ranked as deep plowing > shallow plowing and deep loosening. Respective increases of 7.5% and 4.6% in root biomass productions and peanut yields were obtained when soil bulk density was decreased by 0.1 g cm-3. Our results suggest that the mitigation of soil compaction stress by deep plowing could be a key tillage strategy for increasing peanut yields in the field.

14.
PLoS One ; 11(11): e0166062, 2016.
Article in English | MEDLINE | ID: mdl-27893833

ABSTRACT

Agricultural production can be limited by low phosphorus (P) availability, with soil P being constrained by sorption and precipitation reactions making it less available for plant uptake. There are strong links between carbon (C) and nitrogen (N) availability and P cycling within soil P pools, with microorganisms being an integral component of soil P cycling mediating the availability of P to plants. Here we tested a conceptual model that proposes (i) the addition of readily-available organic substrates would increase the size of the microbial biomass thus exhausting the pool of easily-available P and (ii) this would cause the microbial biomass to access P from more recalcitrant pools. In this model it is hypothesised that the size of the microbial population is regulating access to less available P rather than the diversity of organisms contained within this biomass. To test this hypothesis we added mixtures of simple organic compounds that reflect typical root exudates at different C:N ratios to a soil microcosm experiment and assessed changes in soil P pools, microbial biomass and bacterial diversity measures. We report that low C:N ratio (C:N = 12.5:1) artificial root exudates increased the size of the microbial biomass while high C:N ratio (C:N = 50:1) artificial root exudates did not result in a similar increase in microbial biomass. Interestingly, addition of the root exudates did not alter bacterial diversity (measured via univariate diversity indices) but did alter bacterial community structure. Where C, N and P supply was sufficient to support plant growth the increase observed in microbial biomass occurred with a concurrent increase in plant yield.


Subject(s)
Bacteria/genetics , Lolium/metabolism , Lolium/microbiology , Microbial Consortia , Phosphorus/metabolism , Biomass , Carbon/analysis , Carbon/metabolism , Microbial Consortia/genetics , Microbial Consortia/physiology , Nitrogen/analysis , Nitrogen/metabolism , Phosphorus/pharmacokinetics , RNA, Ribosomal, 16S , Soil/chemistry , Soil Microbiology
15.
Ying Yong Sheng Tai Xue Bao ; 27(12): 3977-3986, 2016 Dec.
Article in Chinese | MEDLINE | ID: mdl-29704358

ABSTRACT

A total of twenty genotypes of peanut (Arachis hypogaea) were used to investigate the differences in nitrogen (N) utilization characteristics in a pot experiment with 15N isotope tracing analysis. Results showed the main N sources for peanut in high fertility soils following as soil N source > N fixed by root nodule source > fertilizer N source. The N uptake and accumulation in peanut from total N and the three N supplied sources (fertilizer N, soil N and N fixation) varied among the different genotypes. N fixation source had the largest genetic variation among the twenty genotypes while genetic variation for fertilizer N source and soil N source were lower and similar. Significant differences showed among the twenty genotypes in pod producing efficiency of N and N use efficiency, and the highest values were respectively 3.6 and 2.1 times of the lowest values. There were also significant differences among the twenty genotypes in the harvest indexes of total N, fertilizer N source, soil N source and N fixation source, and the largest variation showed in the harvest index of N fixation source. The pod yields significantly or extremely significantly corrected with N accumulation amounts from different N sources, N harvest index, pod producing efficiency of N, and N use efficiency. According to N uptake and accumulation and pod yield, four major types of peanut were classified, namely high total N accumulation high yield type, high fertilizer N source high yield type, high soil N source high yield type, and high N fixation source high yield type. Four of the twenty genotypes had all characteristics of the four major types.


Subject(s)
Arachis/physiology , Fertilizers , Nitrogen/chemistry , Soil/chemistry , Arachis/genetics , Genotype , Plant Roots
16.
Ying Yong Sheng Tai Xue Bao ; 22(4): 992-8, 2011 Apr.
Article in Chinese | MEDLINE | ID: mdl-21774323

ABSTRACT

An investigation was made at a double-rice paddy field in the Qiyang Red Soil Field Experimental Station, Hunan Province, China to study the species and biomass of weeds growing in rice (Oryza sativa L.) growth season after 34-year application of sulfur (SO4(2-)) and chloride (Cl(-))-containing chemical fertilizers under the same application rates of nitrogen (N), phosphorus (P), and potassium (K). Long-term application of Cl(-)-containing chemical fertilizer resulted in the greatest species number of weeds and the highest biomass of floating weeds and wet weeds, compared with long-term application of SO4(2-) and Cl(-) +SO4(2-)-containing chemical fertilizers. In early rice growth season, the biomass of weeds after applying Cl(-)-containing chemical fertilizer was 51.4% and 17.6% higher than that after applying Cl(-) + SO4(2-) and SO4(2-)-containing chemical fertilizers, respectively; in late rice growth season, the increment was 144% and 242%, respectively. More floating weeds were observed after applying Cl(-) + SO4(2-) and SO4(2-)-containing chemical fertilizers, but few of them were found after applying Cl(-)-containing chemical fertilizer. The total dry mass of weeds and the dry mass of wet weeds were positively correlated with soil Cl(-) content (r = 0.764, P < 0.01 and r = 0.948, P < 0.01, respectively), but negatively correlated with soil SO4(2-)-S content (r = 0.849, P < 0.01 and r = 0.641, P < 0.05). Soil alkali-hydrolyzable N and available P, under the co-effects of soil SO4(2-)-S, Cl(-), and pH, had indirect effects on the total dry mass of weeds. By adopting various fertilization measures to maintain proper soil pH and alkali-hydrolyzable N and available P contents, increase soil SO42(-)-S content, and decrease soil Cl(-) content, it could be possible to effectively inhibit the growth of wet weeds and to decrease the total biomass of weeds in double-rice paddy field.


Subject(s)
Chlorides/pharmacology , Fertilizers , Oryza/growth & development , Plant Weeds/growth & development , Poaceae/growth & development , Sulfur/pharmacology , China , Ecosystem , Nitrogen/pharmacology , Phosphorus/pharmacology , Time Factors
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