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1.
Environ Sci Technol ; 58(14): 6258-6273, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38450439

RESUMO

Contamination of small-sized plastics is recognized as a factor of global change. Nanoplastics (NPs) can readily enter organisms and pose significant ecological risks. Arbuscular mycorrhizal (AM) fungi are the most ubiquitous and impactful plant symbiotic fungi, regulating essential ecological functions. Here, we first found that an AM fungus, Rhizophagus irregularis, increased lettuce shoot biomass by 25-100% when exposed to positively and negatively charged NPs vs control, although it did not increase that grown without NPs. The stress alleviation was attributed to the upregulation of gene expressions involving phytohormone signaling, cell wall metabolism, and oxidant scavenging. Using a root organ-fungus axenic growth system treated with fluorescence-labeled NPs, we subsequently revealed that the hyphae captured NPs and further delivered them to roots. NPs were observed at the hyphal cell walls, membranes, and spore walls. NPs mediated by the hyphae were localized at the root epidermis, cortex, and stele. Hyphal exudates aggregated positively charged NPs, thereby reducing their uptake due to NP aggregate formation (up to 5000 nm). This work demonstrates the critical roles of AM fungus in regulating NP behaviors and provides a potential strategy for NP risk mitigation in terrestrial ecosystems. Consequent NP-induced ecological impacts due to the affected AM fungi require further attention.


Assuntos
Micorrizas , Micorrizas/metabolismo , Microplásticos , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Hifas , Ecossistema , Expressão Gênica
2.
J Exp Bot ; 73(1): 50-67, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34610119

RESUMO

Rice polluted by metal(loid)s, especially arsenic (As) and cadmium (Cd), imposes serious health risks. Numerous studies have demonstrated that the obligate plant symbionts arbuscular mycorrhizal fungi (AMF) can reduce As and Cd concentrations in rice. The behaviours of metal(loid)s in the soil-rice-AMF system are of significant interest for scientists in the fields of plant biology, microbiology, agriculture, and environmental science. We review the mechanisms of As and Cd accumulation in rice with and without the involvement of AMF. In the context of the soil-rice-AMF system, we assess and discuss the role of AMF in affecting soil ion mobility, chemical forms, transport pathways (including the symplast and apoplast), and genotype variation. A potential strategy for AMF application in rice fields is considered, followed by future research directions to improve theoretical understanding and encourage field application.


Assuntos
Arsênio , Micorrizas , Oryza , Poluentes do Solo , Cádmio/análise , Fungos , Raízes de Plantas/química , Solo , Microbiologia do Solo
3.
Angew Chem Int Ed Engl ; 60(17): 9439-9443, 2021 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-33569888

RESUMO

An efficient general strategy for the synthesis of the Daphniphyllum alkaloids via the rapid construction of a common core intermediate has been established, based on which a divergent total synthesis of (-)-daphenylline and (-)-himalensine A has been accomplished in 16 and 19 steps, respectively. The present work features an enantioselective Mg(ClO4 )2 -catalyzed intramolecular amidocyclization to construct the aza-bridged core structure; a Cu-catalyzed intramolecular cyclopropanation and subsequent phosphine-catalyzed Cope-type rearrangement to furnish the himalensine A scaffold; and a one-pot Diels-Alder/aromatization method to assemble the aromatic skeleton of daphenylline.


Assuntos
Alcaloides/química , Compostos Policíclicos/química , Alcaloides/síntese química , Conformação Molecular , Estereoisomerismo
4.
Angew Chem Int Ed Engl ; 59(38): 16475-16479, 2020 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-32502325

RESUMO

Cyclopianes are novel diterpenes featuring a highly strained 6/5/5/5 tetracyclic core embedded with 6-8 consecutive stereocenters. The concise total syntheses of (-)-conidiogenone B, (-)-conidiogenone, and (-)-conidiogenol have been accomplished in 14-17 steps. The present work features a HAT-mediated alkene-nitrile cyclization to access the cis-biquinane, a Nicholas/Pauson-Khand reaction to construct the linear triquinane, and a Danheiser annulation to afford the congested angular triquinane skeleton.

5.
Ophthalmic Res ; 62(2): 80-92, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31018207

RESUMO

This study aimed to evaluate the therapeutic effect of folic acid (FA) on diabetic retinopathy (DR) in a genetic mouse model of obese type 2 diabetes mellitus (T2D). C57BL/KsJ-db/db (db/db) T2D mice were divided into control, FA, metformin (MET), and FA plus MET groups (n = 10/group). Serum levels of glucose, glycated hemoglobin, and insulin were determined weekly. The retinal thickness was measured using optical coherence tomography (OCT) at 4 weeks after treatments. The retinal expression and serum levels of vascular formation, inflammation, and oxidative stress-associated molecules were examined. Our results demonstrated that FA, but not MET, played a protective role against retinal thinning in the early stage of DR in db/db mice, although FA did not exhibit antihyperglycemic effect. In addition, retinal expression and serum levels of a panel of molecules associated with angiogenesis (CD31 and VEGFR), inflammation (IL-1ß and NLRP3), and oxidative stress (3-NT, 4-HNE, Vav2, and NOX4) were significantly downregulated in FA-treated diabetic mice compared with those in saline-treated controls. Furthermore, the serum level of homocysteine was also markedly decreased following FA treatments. These findings suggest that through potential suppressions on angiogenesis, inflammation, and oxidative stress, FA may serve as a potential therapeutic agent against DR.


Assuntos
Retinopatia Diabética/tratamento farmacológico , Ácido Fólico , Inflamação/metabolismo , Neovascularização Patológica/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Retina , Análise de Variância , Animais , Biomarcadores/metabolismo , Retinopatia Diabética/metabolismo , Retinopatia Diabética/patologia , Modelos Animais de Doenças , Feminino , Ácido Fólico/farmacologia , Ácido Fólico/uso terapêutico , Hemoglobinas Glicadas/análise , Insulina/sangue , Interleucina-1beta/sangue , Camundongos , Camundongos Endogâmicos C57BL , Retina/metabolismo , Retina/patologia , Fator A de Crescimento do Endotélio Vascular/sangue
6.
Angew Chem Int Ed Engl ; 58(17): 5754-5757, 2019 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-30919545

RESUMO

A concise and highly stereoselective total synthesis of the Daphniphyllum alkaloids (-)-daphenylline has been accomplished. The synthesis was started from (S)-carvone and proceeded via a stereoselective Mg(ClO4 )2 -catalyzed intramolecular amide addition cyclization, an intramolecular Diels-Alder reaction to construct the ABCD tetracyclic core architecture, and a Robinson annulation coupled with an oxidative aromatization sequence. Finally, the DF ring system was installed through an intramolecular Friedel-Crafts cyclization. The total synthesis of (-)-daphenylline is achieved in 19 steps in the longest reaction sequence and in 7.6 % overall yield.

7.
Phys Chem Chem Phys ; 20(9): 6383-6389, 2018 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-29441376

RESUMO

Tetrathiafulvalenes (TTFs) are a class of important functional materials whose intermolecular interaction, which will contribute to constructing a supramolecular structure, still needs further understanding. In this study, the self-assembly behavior and structure of a series of TTFs bearing different alkyl chains and substituents were investigated by scanning tunneling microscopy (STM) in combination with density functional theory (DFT) calculations. Contrary to previous reports, herein, a series of benzoic acid-functionalized TTFs (CnTTFCOOH) and pyridine-functionalized TTFs (CnTTFN) with different lengths of alkyl chains have been substituted on the sulfur atom, where n is equal to 8, 10, 14, or 16. Due to the weak intra- and intermolecular interactions, CnTTFN (n = 8 and 10) molecules cannot be observed during STM scanning. For other cases, various self-assembled monolayers with different nanostructures were observed depending on different substituents. The results reveal that the alkyl chains and functional groups on the TTF skeleton synergistically affect the molecular self-assembly process, which results from the synergism of van der Waals, hydrogen bonding, and SS interactions. These results not only help to explain the relationship between structures and properties, but also help to design better molecular structures for various fields.

8.
J Environ Manage ; 225: 17-24, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30071363

RESUMO

Restoration of disturbed habitats (e.g., landfills and mine tailings) is important to recover ecosystem services. Arbuscular mycorrhizal (AM) fungal community is an important indicator of ecological performance of ecosystems. Rhizospheric soils were collected in two sites (A1 and A2) within the restored area of a landfill (18 yrs after restoration), and two sites (B and C, serving as control) in the adjacent natural area. Soil properties were analysed. AM fungal communities in soils were analysed by sequencing 18S small subunit rRNA gene. Results showed that genera Glomus (the most abundant, relative abundance: 10-24%), Paraglomus and Rhizophagus were commonly found at all sites. Acaulospora and Redeckera were found exclusively at natural sites, while Scutellospora only at the restored site. On average, AM fungal species richness was lower (87 operational taxonomy units, OTUs), while diversity was higher (Shannon index 3.2) in restored site, compared with control (107 OTUs, Shannon index 2.8). The structure of the AM fungal communities was influenced by soil nitrogen and cation exchange capacity. The restored sites possessed a more phylogenetically heterogeneous fungal community than that in natural sites. AM fungal community at restored sites clearly deviated from that at natural sites, indicating that current restoration practice is certainly inadequate. The trend of ecological succession could be significantly influenced by rehabilitation methods, such as adjustment of initial soil properties and selection of plant species. This study highlights the necessity of assessing AM fungal community during ecological restoration for sustainable ecosystem, in addition to plant and bacteria.


Assuntos
Micorrizas , Microbiologia do Solo , Instalações de Eliminação de Resíduos , Biodiversidade , Ecossistema , Solo
9.
Environ Sci Pollut Res Int ; 31(30): 42614-42639, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38900405

RESUMO

Anthropogenic activities have caused irreversible consequences on our planet, including climate change and environmental pollution. Nevertheless, reducing greenhouse gas (GHG) emissions and capturing carbon can mitigate global warming. Biochar and hydrochar are increasingly used for soil remediation due to their stable adsorption qualities. As soil amendments, these materials improve soil quality and reduce water loss, prevent cracking and shrinkage, and interact with microbial communities, resulting in a promising treatment method for reducing gas emissions from the top layer of soil. However, during long-term studies, contradictory results were found, suggesting that higher biochar application rates led to higher soil CO2 effluxes, biodiversity loss, an increase in invasive species, and changes in nutrient cycling. Hydrochar, generated through hydrothermal carbonization, might be less stable when introduced into the soil, which could lead to heightened GHG emissions due to quicker carbon breakdown and increased microbial activity. On the other hand, biochar, created via pyrolysis, demonstrates stability and can beneficially impact GHG emissions. Biochar could be the preferred red option for carbon sequestration purposes, while hydrochar might be more advantageous for use as a gas adsorbent. This review paper highlights the ecological impact of long-term applications of biochar and hydrochar in soil. In general, using these materials as soil amendments helps establish a sustainable pool of organic carbon, decreasing atmospheric GHG concentration and mitigating the impacts of climate change.


Assuntos
Carvão Vegetal , Solo , Carvão Vegetal/química , Solo/química , Mudança Climática , Gases de Efeito Estufa
10.
Sci Total Environ ; 929: 172574, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38641094

RESUMO

Environmental pollution and poor feed quality pose potential threats to aquatic organisms and human health, representing challenges for the aquaculture industry. In light of the rising demand for aquatic organisms, there is an urgent need to improve aquacultural production and protect the products from contamination. Char, a carbonaceous material derived through pyrolysis of organic carbon-rich biomass, has proven advantages in soil, air, and water remediation. While char's performance and the associated physicochemical characteristics depend strongly on the pyrolysis temperature, residence time, and feedstock type, char generally shows advantages in pollutant removal from the environment and livestock. This enables it to enhance the health and growth performance of livestock. Given the growing attention to char application in aquaculture in recent years, this review summarises major studies on three applications: aquacultural water treatment, sediment remediation, and char-feed supplement. Most of these studies have demonstrated char's positive effects on pollutant removal from organisms and aquacultural environments. Moreover, adopting char as fish feed can improve fish growth performance and the condition of their intestinal villi. However, due to insufficient literature, further investigation is needed into the mechanistic aspects of pollutants removal in aquatic organisms by char as a feed additive, such as the transportation of char inside aquatic organisms, the positive and negative effects of char on these products, and how char alters the gut microbiota community of these products. This paper presents an overview of the current application of char in aquaculture and highlights the research areas that require further investigation to enrich future studies.


Assuntos
Aquicultura , Carvão Vegetal , Aquicultura/métodos , Carvão Vegetal/química , Ração Animal/análise , Animais , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Recuperação e Remediação Ambiental/métodos , Peixes
11.
Food Sci Anim Resour ; 43(6): 975-988, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37969319

RESUMO

The fatty acid composition and small molecular metabolites in breast and leg meat of Yanjin blackbone chickens (YBC) and Piao chickens (PC) were detected by gas chromatography-mass spectrometry and liquid chromatography-quadrupole static field orbital trap mass spectrometry. Thirty-two fatty acids were detected, and the total fatty acid content of PC was significantly higher than that of YBC (p<0.05). Oleic acid, linoleic acid, palmitic acid, stearic acid, and arachidonic acid were the main fatty acids in the two chicken varieties, and the composition of fatty acids in the two varieties were mainly unsaturated fatty acids, being more than 61.10% of the total fatty acids. Meanwhile, 12 and 16 compounds were screened out from chicken legs and chicken breasts of YBC and PC, respectively, which had important contributions to the differences between groups.

12.
Int J Ophthalmol ; 16(11): 1766-1772, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38028519

RESUMO

AIM: To evaluate the therapeutic effect of folic acid combined with decitabine on diabetic mice. METHODS: The diabetic model of db/db mice were randomly divided into model group, folic acid group, decitabine group, folic acid combined with decitabine group, and C57 mice as normal control group. The density of retinal blood vessels and retinal thickness were detected by fundus photography and optical coherence tomography, respectively. Pathological changes of retina were observed by hematoxylin-eosin (HE) staining. The homocysteine (Hcy) in serum was detected by enzyme linked immunosorbent assay (ELISA). TdT-mediated dUTP nick-end labeling (TUNEL) was used to detect apoptosis in retinal tissue. Evans blue dye was used to detect the permeability of retinal blood vessels. The platelet endothelial cell adhesion molecule-1 (CD31) and vascular endothelial growth factor receptor (VEGFR) protein were detected by Western blot. The 3-nitrotyrosine (3-NT) and 4-hydroxynonanine (4-HNE) were detected by immunohistochemistry. RESULTS: The density of retinal blood vessels, retinal thickness, retinal vascular permeability and the proportion of apoptotic cells of retinal tissue in the model group increased significantly than control group (P<0.05). The Hcy in serum and the levels of CD31, VEGFR, 3-NT, and 4-HNE in retinal tissue increased significantly in the model group (P<0.01). Folic acid and decitabine both reversed these changes significantly, and the combination of the folic acid and decitabine worked best. CONCLUSION: The combination of folic acid and decitabine has a more significant protective effect on the retina in diabetic mice.

13.
Plants (Basel) ; 12(8)2023 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-37111922

RESUMO

Cabbage grown in contaminated soils can accumulate high levels of arsenic (As) in the edible parts, posing serious health risks. The efficiency of As uptake varies drastically among cabbage cultivars, but the underlying mechanisms are not clear. We screened out low (HY, Hangyun 49) and high As accumulating cultivars (GD, Guangdongyizhihua) to comparatively study whether the As accumulation is associated with variations in root physiological properties. Root biomass and length, reactive oxygen species (ROS), protein content, root activity, and ultrastructure of root cells of cabbage under different levels of As stress (0 (control), 1, 5, or 15 mg L-1) were measured As results, at low concentration (1 mg L-1), compared to GD, HY reduced As uptake and ROS content, and increased shoot biomass. At a high concentration (15 mg L-1), the thickened root cell wall and higher protein content in HY reduced arsenic damage to root cell structure and increased shoot biomass compared to GD. In conclusion, our results highlight that higher protein content, higher root activity, and thickened root cell walls result in lower As accumulation properties of HY compared to GD.

14.
Zhonghua Jie He He Hu Xi Za Zhi ; 35(10): 747-51, 2012 Oct.
Artigo em Zh | MEDLINE | ID: mdl-23289991

RESUMO

OBJECTIVES: To observe the immunohistochemical staining of IgG4 in nonspecific interstitial pneumonia (NSIP) and to study the clinicopathological features of IgG4-related NSIP. METHODS: Retrospective analysis was carried out for 32 patients with NSIP who had been admitted into Peking Union Medical College Hospital from November 2002 to October 2010. The diagnosis of NSIP was established by surgical lung biopsy and all specimens were fixed in neutral formalin and embedded in paraffin. Sections were cut for HE and immunohistochemical stain. According to the diagnostic criteria for IgG4-related disease, 4 cases were confirmed to be IgG4-related NSIP. The clinicopathological features including clinical history, laboratory examination, and pathologic evaluation were studied. RESULTS: The 4 patients with IgG4-related NSIP included 1 man and 3 women, with a median age of 48 years (range, 44 - 56 years). The presenting symptoms were dry cough or shortness of breath. One patient (1/4, 25.0%) was found to have a positive autoantibody but no cases showed positive RF in serum. The histological finding of the 4 cases was characterized by inflammatory cell infiltration in interstitium with fibrosis, and 1 case showed obliterative arteritis. The numbers of IgG4-positive plasma cells in the 4 cases were 42/hpf, 22/hpf, 11/hpf, and 33/hpf respectively, while the percentages of IgG4-positive to IgG-positive plasma cells were 70%, 71%, 57%, 43% respectively. CONCLUSIONS: IgG4-related interstitial pulmonary disease can be characterized as the NSIP pattern. The pathological features of IgG4-related NSIP include infiltration of lympho-plasmacytes and eosinophils in interstitium with fibrosis, and lymphoid follicles are frequently identified in the area of lymphocyte aggregation, but obliterative arteritis is infrequently identified in the lesion. Immunohistochemical staining of IgG and IgG4 is very helpful for a definite diagnosis of IgG4-related disease.


Assuntos
Imunoglobulina G/sangue , Doenças Pulmonares Intersticiais/patologia , Adulto , Feminino , Humanos , Doenças Pulmonares Intersticiais/classificação , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
15.
Huan Jing Ke Xue ; 43(2): 1004-1014, 2022 Feb 08.
Artigo em Zh | MEDLINE | ID: mdl-35075874

RESUMO

Clarifying the absorption dynamics of heavy metal(loid)s by crops under different cultivation methods is critical for risk management and control for heavy metal pollution. Here, taking carrots as an example, the pH, cation exchange capacity (CEC), and contents of heavy metals in soil and carrots were analyzed. We compared the absorption and transport characteristics of six metal(loid)s (As, Cd, Cr, Cu, Pb, and Zn) during the three key growth periods under greenhouse and open-field cultivation methods. In addition, the effects of planting methods on carrot biomass and heavy metal content over time were studied, and a health risk assessment was conducted. The results showed that the greenhouse and open-field cultivation methods had the following in common:① As the carrots continuously grew, the metal uptake and biomass in the belowground part (edible part) and the metal(loid) concentrations in the aboveground and belowground parts both showed trends of increasing first and then decreasing or stabilizing. ② The absorption of As, Cd, Cr, and Pb in carrots was mostly accumulated in the aboveground part. ③ The content of Cd in the edible part exceeded the standard, and the total target hazard quotient was>1, indicating potential adverse health risks, most of which were contributed by As and Cd. Compared to that under open-field, the short-term greenhouse cultivation had a harvest time approximately 15 d earlier. The As, Cd, and Pb concentrations in the aboveground part during the seedling and fast-growing periods were significantly lower in the greenhouse than that in the open-field (P<0.05) but did not differ between greenhouse and open-field (except As) at the mature stage. The concentrations of As and Cd in the belowground part of greenhouse carrots were lower in the greenhouse than those of carrots grown in the open-field at the seedling stage (P<0.05). The absorption of As and Cd was decreased significantly from 0 to 95 d (P<0.05), and there was no significant difference in the metal concentration and absorption in the rest of the growth stages. The bioconcentration factors (BCF) of As, Cd, and Pb in the aboveground part in all stages and those of As and Cd in the belowground part in the seedling stage were lower in the greenhouse than that in the open-field. This study emphasizes the possibility of short-term changes in cultivation mode to reduce the risks of metal(loid)s in contaminated farmland vegetables.


Assuntos
Daucus carota , Metais Pesados , Poluentes do Solo , Metais Pesados/análise , Medição de Risco , Solo , Poluentes do Solo/análise , Verduras
16.
BMJ Open ; 12(10): e063622, 2022 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-36253033

RESUMO

OBJECTIVES: We compared clinical performance of three strategies of primary human papillomavirus (HPV) testing, primary cytology and co-testing for cervical cancer screening. DESIGN: A population-based prospective cohort study of clinical performance of screening strategy. SETTING: Patients recruited from community in Changzhi County, Shanxi Province, China. PATIENT: 3209 women aged 30-64 years without gynaecological issues. PRIMARY AND SECONDARY OUTCOME MEASURES: The performance of different screening strategies for detecting cervical intraepithelial neoplasia grade 2 or more severe (CIN2+). RESULTS: A total of 53 CIN2+ and 31 CIN3+ cases are detected. For CIN2+, sensitivity of primary HPV (95.9%) and co-testing (98.0%) are not statistically different, but significantly higher than primary cytology (48.0%). Specificity (86.8%), colposcopy referral rate (7.8%) and number of colposcopies required to detect one case (9.8) for primary HPV are better than co-testing (79.8%, 11.9%, 14.3%, respectively). For CIN3+, primary HPV, co-testing have 100% of sensitivity and specificity, which is significantly higher than primary cytology (56.7% and 90.2%). Number of colposcopies required to detect one case for primary HPV (15.9) is better than co-testing (23.8). CONCLUSIONS: Compared with co-testing, HPV primary screening had comparable sensitivity and higher specificity for CIN2+ detection, and both of them showed better performance than cytology primary screening in cervical cancer screening.


Assuntos
Alphapapillomavirus , Infecções por Papillomavirus , Displasia do Colo do Útero , Neoplasias do Colo do Útero , China , Estudos de Coortes , Detecção Precoce de Câncer , Feminino , Humanos , Programas de Rastreamento , Papillomaviridae , Estudos Prospectivos , Sensibilidade e Especificidade , Neoplasias do Colo do Útero/prevenção & controle , Esfregaço Vaginal
17.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 6): o1404, 2011 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-21754789

RESUMO

The title mol-ecule, C(5)H(4)O(2)S(3), consists of a planar [mean deviation = 0.020 (1) Å] 1,3-dithiole-2-thione unit with an ethyl-enedi-oxy group in the 4,5-positions. The dioxine ring is in a twist-chair conformation.

18.
J Hazard Mater ; 420: 126165, 2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34273883

RESUMO

The low- and high-arsenic (As) transferring cultivars (LTC and HTC) of cabbage showed significant differences in As uptake and distribution. We hypothesise that chemistry of root cell wall matrix plays a critical role. LTC and HTC were treated with As and grown for 60 days. As concentration and distribution at subcellular and cell wall component (pectin, hemicellulose and lignin) levels were determined. Remodelling enzymes (PME and PAL) and functional groups of cell wall were analysed. Results showed that shoot biomass of LTC was not affected by As. Less As was accumulated in shoot of LTC than HTC. LTC allocated more As in root and majority of As was deposited in cell wall. LTC had more hemicellulose 1 (HC1) and lignin, PME and PAL activities. The uronic acid contents of pectin, HC1 or HC2 were all positively (P < 0.05) correlated with As concentrations in each component, respectively. Chemistry of LTC root cell wall was remodelled in terms of changes in porosity, HC and lignin contents, and functional groups, which potentially exerted coupling effects on As entering and deposition. The LTC can restrain As in roots through changing characteristics of root cell wall matrix.


Assuntos
Arsênio , Brassica , Poluentes do Solo , Cádmio/análise , Parede Celular/química , Raízes de Plantas/química , Poluentes do Solo/análise
19.
J Hazard Mater ; 416: 125894, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492832

RESUMO

The chemistry of root cell wall of rice could be changed by inoculation of arbuscular mycorrhizal fungi (AMF). Hydroponic experiments were conducted to investigate the roles of such changes on cadmium (Cd) uptake and distribution in rice. Results showed that inoculation of AM fungus Rhizophagus intraradices (RI) significantly enhanced (p < 0.05) shoot biomass, plant height and root length of rice, and decreased Cd concentration in shoot and root under Cd stress. Moreover, Cd in root was mainly found in pectin and hemicellulose 1 (HC1) components of root cell wall. Inoculation of RI increased the levels of pectin, HC1 and lignin content, accompanied by the increments of L-phenylalanine ammonia-lyase (PAL) and pectin methylesterase (PME) activities. Results of Fourier transform infrared spectroscopy further showed that more hydroxyl and carboxyl groups in root cell wall were observed in mycorrhizal treatment, compared with control. This study demonstrates that cell wall components could be the locations for Cd fixation, which reduced Cd transportation from root to shoot. Inoculation of AMF may remodel root cell wall biosynthesis and affect the characteristics of Cd fixation. The entering and fixing mechanisms should be further studied.


Assuntos
Micorrizas , Oryza , Poluentes do Solo , Cádmio/análise , Parede Celular/química , Fungos , Raízes de Plantas/química , Poluentes do Solo/análise
20.
Sci Total Environ ; 717: 137133, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32062262

RESUMO

Landfills, as the most common approach to disposing of municipal solid waste worldwide, disturb native ecosystems and create a need for ecological restoration. The restoration of landfill cover with biochar has shown immediate potential to improve soil microbial functions within one year. However, such characteristics could change after a longer period of time. Here, soil properties, microbial communities, and microbial functional genes related to nutrient cycling were investigated three years after the biochar amendment of the topsoil of a subtropical landfill cover. The results showed that the levels of soil organic matter, water content, total carbon (C), total nitrogen (N) and total phosphorus (P) of biochar-amended soils were higher than those of control soil. Different soil microbial community structures were observed in the biochar-amended and control soils. Nine phyla, including Proteobacteria and Acidobacteria, but not Actinobacteria or Chloroflexi, were enriched in the biochar-amended soil. Although the impact of biochar on shaping microbial communities increased after a longer period of restoration, no differences were observed in soils that were amended using different biochar:soil ratios. The abundances of functional genes related to C and N cycling decreased, whereas those of genes related to P cycling were higher in soils that received biochar amendment. This finding suggests that compared with the control soil, biochar-amended soils were less active in processes involved in C and N cycling but enhanced in processes related to P cycling. This study can serve as a reference for future ecological restoration of degraded lands using biochar.


Assuntos
Microbiota , Microbiologia do Solo , Solo , Carvão Vegetal , Instalações de Eliminação de Resíduos
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