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1.
J Microbiol ; 59(9): 819-826, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34382148

RESUMO

Phosphate solubilizing fungi (PSF) have been widely applied to dissolve insoluble phosphates (IPs). However, the PSF usually demonstrates a different phosphate solubilizing capacity for various IPs. This study explored the mechanisms of Aspergillus niger for the dissolution of ferric phosphate (FePO4, Fe-P), and tricalcium phosphate (Ca3[PO4]2, Ca-P) regarding the tricarboxylic acid (TCA) cycle. Aspergillus niger has higher phosphorus (P) content released from Ca-P, reached the maximum value of 861 mg/L after seven days of incubation, compared with the 169 mg/L from Fe-P. Oxalic acid promoted the release of P from Ca-P through the formation of calcium oxalate. The presence of Fe-P can stimulate A. niger to secrete large amounts of citric acid, confirmed by the enhancement of citrate synthase (CS) activity. However, citric acid only promotes 0.5% of P released from Fe-P. Meanwhile, although oxalic acid still dominates the release of P from Fe-P, its abundance was significantly declined. In contrast, oxalic acid also shows a higher P release ratio in Ca-P than citric acid, i.e., 36% vs. 22%. This study points to the future usage of A. niger to dissolve IPs in soil required to enhance oxalic acid secretion.


Assuntos
Aspergillus niger/metabolismo , Fosfatos de Cálcio/metabolismo , Compostos Férricos/metabolismo , Aspergillus niger/genética , Fosfatos de Cálcio/química , Citrato (si)-Sintase/genética , Citrato (si)-Sintase/metabolismo , Ácido Cítrico/metabolismo , Compostos Férricos/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Ácido Oxálico/metabolismo , Solo/química
2.
Nat Commun ; 12(1): 4866, 2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-34381045

RESUMO

Plants invest a considerable amount of leaf nitrogen in the photosynthetic enzyme ribulose-1,5-bisphosphate carboxylase-oxygenase (RuBisCO), forming a strong coupling of nitrogen and photosynthetic capacity. Variability in the nitrogen-photosynthesis relationship indicates different nitrogen use strategies of plants (i.e., the fraction nitrogen allocated to RuBisCO; fLNR), however, the reason for this remains unclear as widely different nitrogen use strategies are adopted in photosynthesis models. Here, we use a comprehensive database of in situ observations, a remote sensing product of leaf chlorophyll and ancillary climate and soil data, to examine the global distribution in fLNR using a random forest model. We find global fLNR is 18.2 ± 6.2%, with its variation largely driven by negative dependence on leaf mass per area and positive dependence on leaf phosphorus. Some climate and soil factors (i.e., light, atmospheric dryness, soil pH, and sand) have considerable positive influences on fLNR regionally. This study provides insight into the nitrogen-photosynthesis relationship of plants globally and an improved understanding of the global distribution of photosynthetic potential.


Assuntos
Nitrogênio/metabolismo , Fotossíntese , Folhas de Planta/metabolismo , Clorofila/metabolismo , Clima , Ecossistema , Internacionalidade , Modelos Teóricos , Fósforo/metabolismo , Ribulose-Bifosfato Carboxilase/metabolismo , Solo/química
3.
Commun Biol ; 4(1): 945, 2021 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-34362999

RESUMO

Two challenges that the global wheat industry is facing are a lowering nitrogen-use efficiency (NUE) and an increase in the reporting of wheat-protein related health issues. Sulphur deficiencies in soil has also been reported as a global issue. The current study used large-scale field and glasshouse experiments to investigate the sulphur fertilization impacts on sulphur deficient soil. Here we show that sulphur addition increased NUE by more than 20% through regulating glutamine synthetase. Alleviating the soil sulphur deficiency highly significantly reduced the amount of gliadin proteins indicating that soil sulphur levels may be related to the biosynthesis of proteins involved in wheat-induced human pathologies. The sulphur-dependent wheat gluten biosynthesis network was studied using transcriptome analysis and amino acid metabolomic pathway studies. The study concluded that sulphur deficiency in modern farming systems is not only having a profound negative impact on productivity but is also impacting on population health.


Assuntos
Agricultura/métodos , Fertilizantes/análise , Gliadina/metabolismo , Nitrogênio/metabolismo , Solo/química , Enxofre/administração & dosagem , Triticum/efeitos dos fármacos , Avaliação de Programas e Projetos de Saúde , Triticum/crescimento & desenvolvimento
4.
Nat Commun ; 12(1): 4979, 2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34404804

RESUMO

Relative contributions of pre-existing vs de novo genomic variation to adaptation are poorly understood, especially in polyploid organisms. We assess this in high resolution using autotetraploid Arabidopsis arenosa, which repeatedly adapted to toxic serpentine soils that exhibit skewed elemental profiles. Leveraging a fivefold replicated serpentine invasion, we assess selection on SNPs and structural variants (TEs) in 78 resequenced individuals and discover significant parallelism in candidate genes involved in ion homeostasis. We further model parallel selection and infer repeated sweeps on a shared pool of variants in nearly all these loci, supporting theoretical expectations. A single striking exception is represented by TWO PORE CHANNEL 1, which exhibits convergent evolution from independent de novo mutations at an identical, otherwise conserved site at the calcium channel selectivity gate. Taken together, this suggests that polyploid populations can rapidly adapt to environmental extremes, calling on both pre-existing variation and novel polymorphisms.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Adaptação Fisiológica/genética , Alelos , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Genoma de Planta , Poliploidia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Canais de Cálcio/metabolismo , Mutação , Polimorfismo de Nucleotídeo Único , Alcaloides de Triptamina e Secologanina/metabolismo , Solo/química
5.
BMC Plant Biol ; 21(1): 372, 2021 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-34388971

RESUMO

BACKGROUND: Oilseed rape (B. napus L.) has great potential for phytoremediation of cadmium (Cd)-polluted soils due to its large plant biomass production and strong metal accumulation. Soil properties and the presence of other soluble compounds or ions, cause a heterogeneous distribution of Cd. RESULTS: The aim of our study was to reveal the differential responses of B. napus to different Cd abundances. Herein, we found that high Cd (50 µM) severely inhibited the growth of B. napus, which was not repressed by low Cd (0.50 µM) under hydroponic culture system. ICP-MS assays showed that the Cd2+ concentrations in both shoots and roots under 50 µM Cd were over 10 times higher than those under 0.50 µM Cd. Under low Cd, the concentrations of only shoot Ca2+/Mn2+ and root Mn2+ were obviously changed (both reduced); under high Cd, the concentrations of most cations assayed were significantly altered in both shoots and roots except root Ca2+ and Mg2+. High-throughput transcriptomic profiling revealed a total of 18,021 and 1408 differentially expressed genes under high Cd and low Cd conditions, respectively. The biological categories related to the biosynthesis of plant cell wall components and response to external stimulus were over-accumulated under low Cd, whereas the terms involving photosynthesis, nitrogen transport and response, and cellular metal ion homeostasis were highly enriched under high Cd. Differential expression of the transporters responsible for Cd uptake (NRAMPs), transport (IRTs and ZIPs), sequestration (HMAs, ABCs, and CAXs), and detoxification (MTPs, PCR, MTs, and PCSs), and some other essential nutrient transporters were investigated, and gene co-expression network analysis revealed the core members of these Cd transporters. Some Cd transporter genes, especially NRAMPs and IRTs, showed opposite responsive patterns between high Cd and low Cd conditions. CONCLUSIONS: Our findings would enrich our understanding of the interaction between essential nutrients and Cd, and might also provide suitable gene resources and important implications for the genetic improvement of plant Cd accumulation and resistance through molecular engineering of these core genes under varying Cd abundances in soils.


Assuntos
Brassica napus/genética , Brassica napus/metabolismo , Cádmio/metabolismo , Transporte Biológico , Brassica napus/crescimento & desenvolvimento , Quelantes/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Íons/metabolismo , Solo/química , Tetraploidia , Transcriptoma
6.
BMC Plant Biol ; 21(1): 379, 2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34407754

RESUMO

BACKGROUND: The decrease in Cunninghamia lanceolata (Lamb.) production on continuously planted soil is an essential problem. In this study, two-year-old seedlings of two cultivars (a normal cultivar, NC, and a super cultivar, SC) were grown in two types of soil (not planted (NP) soil; continuously planted (CP) soil) with three watering regimes, and the interactive effects on plant growth and physiological traits were investigated in a greenhouse experiment. The water contents of the soil in the control (CK) (normal water content), medium water content (MWC) and low water content (LWC) treatments reached 75-80 %, 45-50 % and 20-25 % of the field water capacity, respectively. RESULTS: The results indicated that the CP soil had a negative effect on growth and physiological traits and that the LWC treatment caused even more severe and comprehensive negative effects. In both cultivars, the CP soil significantly decreased the height increment (HI), basal diameter increment (DI), dry matter accumulation (DMA), net photosynthetic rate (Pn), total chlorophyll content (TChl), carotenoid content (Caro) and photosynthetic nitrogen use efficiency (PNUE). Compared to the NP soil, the CP soil also decreased the proline and soluble protein contents, nitrogen use efficiency (NUE) and phosphorus use efficiency (PUE) and increased the nitrogen:phosphorus ratio in roots, stems and leaves. The LWC treatment decreased growth and photosynthesis, changed ecological stoichiometry, induced oxidative stress, promoted water use efficiency and damaged chloroplast ultrastructure. Significant increases in ascorbate peroxidase (APX), peroxidase (POD), soluble protein and proline contents were found in the LWC treatment. Compared with the NC, the SC was more tolerant to the CP soil and water stress, as indicated by the higher levels of DMA, Pn, and WUE. After exposure to the CP soil and watering regimes, the decreases in biomass accumulation and gas exchange were more pronounced. CONCLUSIONS: The combination of drought and CP soil may have detrimental effects on C. lanceolata growth, and low water content enhances the impacts of CP soil stress on C. lanceolata seedlings. The superiority of the SC over the NC is significant in Chinese fir plantation soil. Therefore, continuously planted soil can be utilized to cultivate improved varieties of C. lanceolata and maintain water capacity. This can improve their growth and physiological performance to a certain extent.


Assuntos
Adaptação Fisiológica , Cunninghamia/anatomia & histologia , Cunninghamia/crescimento & desenvolvimento , Cunninghamia/genética , Cunninghamia/metabolismo , Secas , Solo/química , Água/metabolismo , China , Variação Genética , Genótipo
7.
Molecules ; 26(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34361755

RESUMO

Zinc (Zn) is an essential micronutrient for plant growth, and Zn deficiency is a global issue, especially in tropical soils. This study aimed to investigate the effects of humic acid (HA) and the Zn addition (Zn sulfate + HA) on the growth of maize and brachiaria in two contrasting Oxisols. The potential complexation of Zn sulfate by HA was evaluated by Fourier-transform infrared (FTIR) spectroscopy analysis. Zinc content and its availability in solution and the shoot and root biomass of maize and brachiaria were determined. FTIR spectroscopy revealed the complexation of Zn sulfate by HA through its S and C functional groups. In both Oxisols, solution Zn increased due to the combined use of Zn and HA. In a soil type-dependent manner, maize biomass and Zn in its shoots were affected only by the exclusive use of Zn fertilization. In the Yellow Oxisol, brachiaria growth and Zn accumulated in its shoot were positively affected by the combined use of Zn fertilization with HA. In the Oxisol with lower organic matter content, HA can assure adequate supplying of residual Zn, while increasing growth of brachiaria cultivated in sequence to maize.


Assuntos
Brachiaria/efeitos dos fármacos , Substâncias Húmicas/análise , Solo/química , Zea mays/efeitos dos fármacos , Sulfato de Zinco/farmacologia , Brachiaria/crescimento & desenvolvimento , Brasil , Fertilizantes/análise , Concentração de Íons de Hidrogênio , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/crescimento & desenvolvimento , Análise de Componente Principal , Espectroscopia de Infravermelho com Transformada de Fourier , Zea mays/crescimento & desenvolvimento , Sulfato de Zinco/análise , Sulfato de Zinco/química
8.
Molecules ; 26(16)2021 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-34443509

RESUMO

The main goal of this work was to study the structural transformation of humic acids (HAs) under the influence of selected strains of fungi (Aspergillus niger and Paecilomyces lilacinus) and bacteria (Bacillus sp., Paenibacillus polymyxa and Bacillus amyloliquefaciens) with/without the presence of NPK fertilizers. Two-year experiments were conducted on two different soils and HAs isolated from these soils were examined for structure, humification degree, and quantity using fluorescence and UV-Vis spectroscopy, elemental analysis, and extraction methods. Results showed that the applied additives contributed to the beneficial transformation of HAs, but effects differed for various soils. HAs from silty soil with higher organic carbon content showed simplification of their structure, and decreases in humification, molecular weight, and aromaticity under the influence of fungi and bacteria without NPK, and with NPK alone. With both fungi and NPK, increases in O/H and O/C atomic ratios indicated an increase in the number of O-containing functional groups. HAs from sandy soil did not show as many significant changes as did those from silty soil. Sandy soil exhibited a strong decline in HA content in the second year that was reduced/neutralized by the presence of fungi, bacteria, and NPK. Periodically observed fluorescence at ~300 nm/450 nm reflected formation of low-molecular HAs originating from the activity of microorganisms.


Assuntos
Agricultura , Bactérias/efeitos dos fármacos , Fertilizantes/análise , Fungos/efeitos dos fármacos , Substâncias Húmicas/análise , Minerais/farmacologia , Solo/química , Fluorescência , Espectrofotometria Ultravioleta
9.
Molecules ; 26(16)2021 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-34443694

RESUMO

Thymus vulgaris L. is one of the most commonly used medicinal and aromatic plants (MAPs), owing to a range of therapeutic properties of its essential oil. Plant growth, biomass yield, essential oil content and composition are influenced by chemotype, environmental conditions, cultivation techniques and vegetative development. Since in MAPs cultivation special attention is paid on high quality of raw material, the adoption of sustainable agriculture methods is of pivotal importance. Therefore, we evaluated the agronomic and qualitative performances of two Thymus vulgaris L. chemotypes, organically cultivated under the Mediterranean climate of hilly lands of central Italy for three consecutive years (2017-2019). Along the trial, total above-ground dry biomass significantly increased from the 1st to 3rd year after planting and large variations in the main biological, biometric and productive traits were observed between the two chemotypes. The 'thymol' chemotype EO obviously showed thymol as the major constituent (51.26-49.87%) followed by γ-terpinene and p-cymene. The 'linalool' chemotype EO showed high percentages of oxygenated monoterpenes (about 90%) with linalool (75%), linalyl acetate (8.15%) and b-caryophyllene (3.2%) as main constituents. This study highlighted that T. vulgaris can be successfully organically grown in the hilly lands of Tuscany, with interesting biomass and essential oil yields, even though the plants were in the initial years of crop establishment (start in 2017). The introduction of this species into organic cultivation systems could contribute to obtain high-quality raw material, as well as to enhance crop rotation diversification, which is of pivotal importance in the management of organic farms.


Assuntos
Produtos Agrícolas/crescimento & desenvolvimento , Óleos Voláteis/análise , Thymus (Planta)/química , Destilação , Itália , Análise de Componente Principal , Chuva , Estações do Ano , Solo/química
10.
BMC Plant Biol ; 21(1): 362, 2021 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-34364388

RESUMO

BACKGROUND: The root rot of fragrant solomonseal (Polygonatum odoratum) has occurred frequently in the traditional P. odoratum cultivating areas in recent years, causing a heavy loss in yield and quality. The phenolic acids in soil, which are the exudates from the P. odoratum root, act as allelochemicals that contribute to the consecutive monoculture problem (CMP) of the medicinal plant. The aim of this study was to get a better understanding of P. odoratum CMP. RESULTS: The phenolic acid contents, the nutrient chemical contents, and the enzyme activities related to the soil nutrient metabolism in the first cropping (FC) soil and continuous cropping (CC) soil were determined, and the differentially expressed genes (DEGs) related to the regulation of the phenolic acids in roots were analyzed. The results showed that five low-molecule-weight phenolic acids were detected both in the CC soil and FC soil, but the phenolic acid contents in the CC soil were significantly higher than those in the FC soil except vanillic acid. The contents of the available nitrogen, available phosphorus, and available potassium in the CC soil were significantly decreased, and the activities of urease and sucrase in the CC soil were significantly decreased. The genomic analysis showed that the phenolic acid anabolism in P. odoratum in the CC soil was promoted. These results indicated that the phenolic acids were accumulated in the CC soil, the nutrient condition in the CC soil deteriorated, and the nitrogen metabolism and sugar catabolism of the CC soil were lowered. Meantime, the anabolism of phenolic acids was increased in the CC plant. CONCLUSIONS: The CC system promoted the phenolic acid anabolism in P. odoratum and made phenolic acids accumulate in the soil.


Assuntos
Agricultura/métodos , Hidroxibenzoatos/análise , Polygonatum/genética , Solo/química , Enzimas/análise , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Hidroxibenzoatos/metabolismo , Nitrogênio/análise , Fósforo/análise , Proteínas de Plantas/genética , Plantas Medicinais , Polygonatum/metabolismo , Rizosfera , Análise de Sequência de RNA
11.
Molecules ; 26(13)2021 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-34206860

RESUMO

In this paper, a combination of modification of the source and regulation of the process was used to control the degradation of PBDEs by plants and microorganisms. First, the key proteins that can degrade PBDEs in plants and microorganisms were searched in the PDB (Protein Data Bank), and a molecular docking method was used to characterize the binding ability of PBDEs to two key proteins. Next, the synergistic binding ability of PBDEs to the two key proteins was evaluated based on the queuing integral method. Based on this, three groups of three-dimensional quantitative structure-activity relationship (3D-QSAR) models of plant-microbial synergistic degradation were constructed. A total of 30 PBDE derivatives were designed using BDE-3 as the template molecule. Among them, the effect on the synergistic degradation of six PBDE derivatives, including BDE-3-4, was significantly improved (increased by more than 20%) and the environment-friendly and functional evaluation parameters were improved. Subsequently, studies on the synergistic degradation of PBDEs and their derivatives by plants and microorganisms, based on the molecular docking method, found that the addition of lipophilic groups by modification is beneficial to enhance the efficiency of synergistic degradation of PBDEs by plants and microorganisms. Further, while docking PBDEs, the number of amino acids was increased and the binding bond length was decreased compared to the template molecules, i.e., PBDE derivatives could be naturally degraded more efficiently. Finally, molecular dynamics simulation by the Taguchi orthogonal experiment and a full factorial experimental design were used to simulate the effects of various regulatory schemes on the synergistic degradation of PBDEs by plants and microorganisms. It was found that optimal regulation occurred when the appropriate amount of carbon dioxide was supplied to the plant and microbial systems. This paper aims to provide theoretical support for enhancing the synergistic degradation of PBDEs by plants and microorganisms in e-waste dismantling sites and their surrounding polluted areas, as well as, realize the research and development of green alternatives to PBDE flame retardants.


Assuntos
Retardadores de Chama/análise , Éteres Difenil Halogenados/química , Plantas/metabolismo , Poluentes do Solo/química , Solo/química , Dióxido de Carbono/química , Dióxido de Carbono/metabolismo , Bases de Dados de Proteínas , Éteres Difenil Halogenados/análise , Modelos Moleculares , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Relação Quantitativa Estrutura-Atividade , Microbiologia do Solo
12.
Nat Commun ; 12(1): 4431, 2021 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-34290234

RESUMO

Experiments showed that biodiversity increases grassland productivity and nutrient exploitation, potentially reducing fertiliser needs. Enhancing biodiversity could improve P-use efficiency of grasslands, which is beneficial given that rock-derived P fertilisers are expected to become scarce in the future. Here, we show in a biodiversity experiment that more diverse plant communities were able to exploit P resources more completely than less diverse ones. In the agricultural grasslands that we studied, management effects either overruled or modified the driving role of plant diversity observed in the biodiversity experiment. Nevertheless, we show that greater above- (plants) and belowground (mycorrhizal fungi) biodiversity contributed to tightening the P cycle in agricultural grasslands, as reduced management intensity and the associated increased biodiversity fostered the exploitation of P resources. Our results demonstrate that promoting a high above- and belowground biodiversity has ecological (biodiversity protection) and economical (fertiliser savings) benefits. Such win-win situations for farmers and biodiversity are crucial to convince farmers of the benefits of biodiversity and thus counteract global biodiversity loss.


Assuntos
Agricultura/métodos , Biodiversidade , Pradaria , Fósforo/metabolismo , Agricultura/economia , Biomassa , Fertilizantes/economia , Análise de Classes Latentes , Micorrizas/classificação , Micorrizas/metabolismo , Fósforo/análise , Fósforo/economia , Plantas/classificação , Plantas/metabolismo , Plantas/microbiologia , Solo/química , Microbiologia do Solo
13.
Molecules ; 26(13)2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34202843

RESUMO

The aim of this study was to assess the enzymatic and non-enzymatic antioxidant status of kiwiberry (Actinidia arguta) leaf under different N regimes tested three times in field conditions during the 2015 growing season in two cultivars ('Weiki' and 'Geneva'). Leaf total antioxidant capacity using ABTS, DPPH and FRAP tests was evaluated in the years 2015 to 2017, which experienced different weather conditions. Both cultivars exhibited a significant fall in leaf L-ascorbic acid (L-AA) and reduced glutathione (GSH) as well as global content of these compounds during the growing season, while total phenolic contents slightly ('Weiki') or significantly ('Geneva') increased. There was a large fluctuation in antioxidative enzyme activity during the season. The correlation between individual antioxidants and trolox equivalent antioxidant capacity (TEAC) depended on the plant development phase. The study revealed two peaks of an increase in TEAC at the start and end of the growing season. Leaf L-AA, global phenolics, APX, CAT and TEAC depended on the N level, but thiol compounds were not affected. Over the three years, TEAC decreased as soil N fertility increased, and the strength of the N effect was year dependent. The relationship between leaf N content and ABTS and FRAP tests was highly negative. The antioxidant properties of kiwiberry leaves were found to be closely related to the plant development phase and affected by soil N fertility.


Assuntos
Actinidia/química , Nitrogênio/química , Compostos Fitoquímicos/química , Folhas de Planta/química , Solo/química , Actinidia/crescimento & desenvolvimento , Nitrogênio/metabolismo , Compostos Fitoquímicos/biossíntese , Folhas de Planta/crescimento & desenvolvimento , Especificidade da Espécie
14.
Molecules ; 26(11)2021 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-34205200

RESUMO

Excessive use of nitrogen fertilizer in intensively managed agriculture has resulted in abundant accumulation of nitrate in soil, which limits agriculture sustainability. How to reduce nitrate content is the key to alleviate secondary soil salinization. However, the microorganisms used in soil remediation cause some problems such as weak efficiency and short survival time. In this study, seaweed polysaccharides were used as stimulant to promote the rapid growth and safer nitrate removal of denitrifying bacteria. Firstly, the growth rate and NO3--N removal capacity of three kinds of denitrifying bacteria, Bacillus subtilis (BS), Pseudomonas stutzeri (PS) and Pseudomonas putida (PP), were compared. The results showed that Bacillus subtilis (BS) had a faster growth rate and stronger nitrate removal ability. We then studied the effects of Enteromorpha linza polysaccharides (EP), carrageenan (CA), and sodium alginate (AL) on growth and denitrification performance of Bacillus subtilis (BS). The results showed that seaweed polysaccharides obviously promoted the growth of Bacillus subtilis (BS), and accelerated the reduction of NO3--N. More importantly, the increased NH4+-N content could avoid excessive loss of nitrogen, and less NO2--N accumulation could avoid toxic effects on plants. This new strategy of using denitrifying bacteria for safely remediating secondary soil salinization has a great significance.


Assuntos
Bactérias/crescimento & desenvolvimento , Nitratos/metabolismo , Polissacarídeos/farmacologia , Alga Marinha/química , Bacillus subtilis/crescimento & desenvolvimento , Bacillus subtilis/metabolismo , Bactérias/metabolismo , Biodegradação Ambiental , Desnitrificação , Pseudomonas putida/crescimento & desenvolvimento , Pseudomonas putida/metabolismo , Pseudomonas stutzeri/crescimento & desenvolvimento , Pseudomonas stutzeri/metabolismo , Solo/química , Microbiologia do Solo
15.
Molecules ; 26(12)2021 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-34207649

RESUMO

Micronutrient malnutrition is a global health issue and needs immediate attention. Over two billion people across the globe suffer from micronutrient malnutrition. The widespread zinc (Zn) deficiency in soils, poor zinc intake by humans in their diet, low bioavailability, and health consequences has led the research community to think of an economic as well as sustainable strategy for the alleviation of zinc deficiency. Strategies like fortification and diet supplements, though effective, are not economical and most people in low-income countries cannot afford them, and they are the most vulnerable to Zn deficiency. In this regard, the biofortification of staple food crops with Zn has been considered a useful strategy. An agronomic biofortification approach that uses crop fertilization with Zn-based fertilizers at the appropriate time to ensure grain Zn enrichment has been found to be cost-effective, easy to practice, and efficient. Genetic biofortification, though time-consuming, is also highly effective. Moreover, a Zn-rich genotype once developed can also be used for many years without any recurring cost. Hence, both agronomic and genetic biofortification can be a very useful tool in alleviating Zn deficiency.


Assuntos
Biofortificação/métodos , Produtos Agrícolas/genética , Fertilizantes/análise , Alimentos Fortificados/normas , Desnutrição/dietoterapia , Solo/química , Zinco/química , Humanos , Desnutrição/fisiopatologia , Estado Nutricional
16.
Se Pu ; 39(8): 878-888, 2021 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-34212588

RESUMO

The complexity of the soil matrix, as well as the wide spectrum and trace levels of antibiotic residues in soil, make highly sensitive instrumental methods, efficient purification and enrichment methods, and simultaneous determination of multiple antibiotics key and challenging aspects in the analysis of antibiotics in soil. In this study, a solid phase extraction-ultra-high performance liquid chromatography-tandem mass spectrometry (SPE-UHPLC-MS/MS) method was developed for the simultaneous determination of 30 antibiotics (grouped into seven categories: sulfonamides, fluoroquinolones, tetracyclines, macrolides, ß-lactams, amphenicols, and lincosamides) in soil samples. In the UHPLC-MS/MS experiment, florfenicol and chloramphenicol were analyzed in the negative ionization multiple-reaction monitoring (MRM) mode, and the other 28 target analytes were analyzed in the positive MRM mode. Sensitive MS conditions were realized by optimizing the instrumental parameters such as collision energy and declustering potential. The effects of the injection solvent (proportion of methanol to water) and mobile phase (types and compositions of the solvents) on the shape and intensity of the chromatographic peaks were studied. The optimized UHPLC conditions were as follows: injection solvent, 10%(v/v) methanol aqueous solution; chromatographic column, BEH-C18 column; mobile phase, methanol and water both containing 0.1%(v/v) formic acid; flow rate, 0.4 mL/min; sample injection volume, 5.0 µL. The effects of the extraction solution (the types and compositions of solvents) and clean-up processes (pH of the loading solution, as well as the types and compositions of the rinse solution and elution solvent) on the method performance were investigated. The acetonitrile/Na2EDTA-McIlvaine buffer showed better extraction efficiency for fluoroquinolones than did the methanol/Na2EDTA-McIlvaine buffer. Improved recoveries of sulfonamides, macrolides, tetracyclines, and ß-lactams were observed when the pH of the loading solution was set to 8.0. The recoveries of sulfadiazine and amoxicillin increased with a decrease in the proportion of methanol to water for the rinse solution. Compared to individual methanol or acetonitrile, the methanol-acetonitrile (1∶1, v/v) mixture showed better elution efficiency for the target analytes. The optimized pretreatment conditions were determined as follows: the soil sample was spiked with mixed internal standards, and then extracted with 10 mL of acetonitrile/Na2EDTA-McIlvaine buffer (1∶1, v/v) by shaking for 30 min and ultrasonication for 15 min. The extraction was repeated three times. The sample extract was adjusted to pH 8.0 and loaded onto an Oasis HLB cartridge for purification. The cartridge was rinsed with 10 mL of water to remove impurities and eluted with 10 mL of methanol-acetonitrile (1∶1, v/v). Quantitative analysis was conducted using the isotope internal standard method. The method limits of detection and quantification were in the range of 0.013-1.21 and 0.043-4.04 µg/kg, respectively. The correlation coefficients of the calibration curve were 0.992-1.00, suggesting good linearity of the method. At three spiked levels (20, 100, and 200 µg/kg), the average recoveries of most target antibiotics were 44.8% to 164%, and the relative standard deviations were 0.700% to 14.8%. The method was successfully applied to the analysis of the 30 antibiotics in six soil samples. Seventeen antibiotics were detected in the soil samples, and the total contents of the antibiotics in each sample ranged from 73.4 to 184 µg/kg. Twelve antibiotics with a detection frequency of 100% included roxithromycin, clarithromycin, ciprofloxacin, norfloxacin, enrofloxacin, ofloxacin, fleroxacin, lomefloxacin, oxytetracycline, doxycycline, tetracycline, and penicillin G. Ciprofloxacin and norfloxacin were the predominant antibiotics in the soils, with contents in the range of 13.7-32.1 and 15.6-43.6 µg/kg, respectively. The developed method is simple, rapid, and solvent-saving, and it shows promise for use in the simultaneous determination of trace levels of the 30 antibiotics in soil.


Assuntos
Antibacterianos , Poluentes do Solo/análise , Solo/química , Antibacterianos/análise , Cromatografia Líquida de Alta Pressão , Extração em Fase Sólida , Espectrometria de Massas em Tandem
17.
Molecules ; 26(11)2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34205887

RESUMO

Increasing heavy metal pollution in the environment and the fact that pine needles are good bio-monitors for air pollutants was the reason to investigate their accumulation in pine needles in Vienna (Austria). Pinus nigra is widespread over the city, thus allowing the study of different parameters influencing metal accumulation. The sampling sites were chosen based on traffic volume (low, medium, high). Fresh shoots were collected alongside one-year-old needles once per week from May to August 2015. The needle samples were washed and dried prior to acidic microwave-assisted digestion followed by quantitative determination using spectrometric methods. The investigation was focused on the following elements: Ag, Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Se, Sr, U, V, and Zn. The one-year-old needles mainly contained higher contents of elements than fresh shoots; in many cases, the values differed statistically significantly. By correlating needle elemental contents with the sampling site, statistically significant differences were registered for the majority of the investigated elements. These differences originate from the local traffic situation, soil elemental levels, translocation processes, and not traffic-related sources. No general trend of metal accumulation from spring to summer was registered.


Assuntos
Metais Pesados/análise , Pinus/química , Oligoelementos/análise , Áustria , Monitoramento Ambiental , Especificidade de Órgãos , Brotos de Planta/química , Solo/química
18.
Nat Commun ; 12(1): 4562, 2021 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-34315908

RESUMO

Plant and soil C:N:P ratios are of critical importance to productivity, food-web dynamics, and nutrient cycling in terrestrial ecosystems worldwide. Plant diversity continues to decline globally; however, its influence on terrestrial C:N:P ratios remains uncertain. By conducting a global meta-analysis of 2049 paired observations in plant species mixtures and monocultures from 169 sites, we show that, on average across all observations, the C:N:P ratios of plants, soils, soil microbial biomass and enzymes did not respond to species mixture nor to the species richness in mixtures. However, the mixture effect on soil microbial biomass C:N changed from positive to negative, and those on soil enzyme C:N and C:P shifted from negative to positive with increasing functional diversity in mixtures. Importantly, species mixture increased the C:N, C:P, N:P ratios of plants and soils when background soil C:N, C:P, and N:P were low, but decreased them when the respective background ratios were high. Our results demonstrate that plant mixtures can balance terrestrial plant and soil C:N:P ratios dependent on background soil C:N:P. Our findings highlight that plant diversity conservation does not only increase plant productivity, but also optimizes ecosystem stoichiometry for the diversity and productivity of today's and future vegetation.


Assuntos
Carbono/análise , Ecossistema , Nitrogênio/análise , Fósforo/análise , Plantas/química , Biodiversidade , Biomassa , Solo/química , Microbiologia do Solo
19.
Nat Commun ; 12(1): 4115, 2021 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-34226560

RESUMO

The largest terrestrial organic carbon pool, carbon in soils, is regulated by an intricate connection between plant carbon inputs, microbial activity, and the soil matrix. This is manifested by how microorganisms, the key players in transforming plant-derived carbon into soil organic carbon, are controlled by the physical arrangement of organic and inorganic soil particles. Here we conduct an incubation of isotopically labelled litter to study effects of soil structure on the fate of litter-derived organic matter. While microbial activity and fungal growth is enhanced in the coarser-textured soil, we show that occlusion of organic matter into aggregates and formation of organo-mineral associations occur concurrently on fresh litter surfaces regardless of soil structure. These two mechanisms-the two most prominent processes contributing to the persistence of organic matter-occur directly at plant-soil interfaces, where surfaces of litter constitute a nucleus in the build-up of soil carbon persistence. We extend the notion of plant litter, i.e., particulate organic matter, from solely an easily available and labile carbon substrate, to a functional component at which persistence of soil carbon is directly determined.


Assuntos
Carbono/química , Material Particulado , Microbiologia do Solo , Solo/química , Biomassa , Ácidos Graxos , Fungos , Processos Heterotróficos , Minerais/química , Plantas
20.
Artigo em Inglês | MEDLINE | ID: mdl-34283016

RESUMO

Two halophilic archaeal strains, Gai3-2T and NJ-3-1T, were isolated from salt lake and saline soil samples, respectively, collected in PR China. The 16S rRNA gene sequences of the two strains were 97.5% similar to each other. Strains Gai3-2T and NJ-3-1T had the highest sequence similarities to 'Halobonum tyrrellense' G22 (96.7 and 97.8%, respectively), and displayed similarities of 91.5-93.5% and 92.3-94.7%, respectively, to Halobaculum members. Phylogenetic analysis revealed that the two strains formed different branches and clustered tightly with 'H. tyrrellense' G22 and Halobaculum members. The average nucleotide identity (ANI), in silico DNA-DNA hybridization (isDDH) and amino acid identity (AAI) values between the two strains were 83.1, 26.9 and 77.9%, respectively, much lower than the threshold values proposed as a species boundary. These values between the two strains and 'H. tyrrellense' G22 (ANI 77.9-78.2%, isDDH 22.5-22.6% and AAI 68.8-69.3%) and Halobaculum members (ANI 77.53-77.63%, isDDH 21.8-22.3% and AAI 68.4-69.4%) were almost identical, and much lower than the recommended threshold values for species delimitation. These results suggested that strains Gai3-2T and NJ-3-1T represent two novel species of Halobaculum. Based on phenotypic, chemotaxonomic and phylogenetic properties, strains Gai3-2T (=CGMCC 1.16080T=JCM 33550T) and NJ-3-1T (=CGMCC 1.16040T=JCM 33552T) represent two novel species of the genus Halobaculum, for which the name Halobaculum halophilum sp. nov. and Halobaculum salinum sp. nov. are proposed.


Assuntos
DNA Arqueal/isolamento & purificação , Halobacteriaceae/isolamento & purificação , Lagos/análise , Extratos Vegetais/isolamento & purificação , Solo/química , DNA Arqueal/genética , Halobacteriaceae/genética , Filogenia , Extratos Vegetais/genética , Análise de Sequência de DNA/métodos
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