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1.
J Environ Manage ; 354: 120479, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38401498

RESUMO

Sediment associated carbon and nitrogen loss under rainfall, an important cause of soil quality degradation and water eutrophication, strongly depends on the intrinsic properties of original soil types. Relative to total loss, the transport behaviors of organic carbon and nitrogen among sediment size classes and response to soil types remain poorly understood. The concentrations of organic carbon (OC) and total nitrogen (TN) in different sediment size classes (>1, 0.25-1, 0.10-0.25, and <0.10 mm) and their contributions to total sediment load during rainfall erosion were determined under field plot rainfall simulation (at 90 mm h-1) on three contrasting soil types (Luvisol, Alisol and Ferralsol) with increased aggregate stability. During rainfall erosion, the concentrations of OC and TN in total and different sized sediments decreased first and then reached a steady state. The variability of OC and TN concentrations (coefficient of variations in 4.2-53.1% and 6.6-41.9%) among sediment size classes decreased from Luvisol to Ferralsol. Compared to original soils, sediments exhibited larger C/N ratios for Luvisol, and smaller values for Alisol, indicating the more selective transport of labile organic matter for weaker aggregated soils. Among sediment size classes, fine particles (<0.10 mm) accounted 69-88% of total OC and TN losses for Luvisol, and decreased to 30-39% for Ferralsol; and the main transport mechanisms of sediment associated OC and TN shifting from suspension-saltation (<0.10 mm) to rolling (>0.25 mm) with increased aggregate stability. Among original soil properties, inorganic cementing agents (including amorphous iron oxides and clay minerals) showed closer relationships with sediment OC and TN losses (|r| = 0.61-0.89, p < 0.001) than organic matter properties (|r| = 0.55-0.87, p < 0.001), further implying the important role of soil aggregate stability across soil types. This study provides an in-depth understanding on soil carbon and nitrogen losses and their divergent characteristics among soil types deserves consideration in the development of erosion model and land management in agricultural systems.


Assuntos
Carbono , Solo , Carbono/análise , Nitrogênio/análise , Agricultura , Eutrofização , China
2.
J Environ Manage ; 358: 120917, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38663084

RESUMO

Permafrost regions play an important role in global carbon and nitrogen cycling, storing enormous amounts of organic carbon and preserving a delicate balance of nutrient dynamics. However, the increasing frequency and severity of wildfires in these regions pose significant challenges to the stability of these ecosystems. This review examines the effects of fire on chemical, biological, and physical properties of permafrost regions. The physical, chemical, and pedological properties of frozen soil are impacted by fires, leading to changes in soil structure, porosity, and hydrological functioning. The combustion of organic matter during fires releases carbon and nitrogen, contributing to greenhouse gas emissions and nutrient loss. Understanding the interactions between fire severity, ecosystem processes, and the implications for permafrost regions is crucial for predicting the impacts of wildfires and developing effective strategies for ecosystem protection and agricultural productivity in frozen soils. By synthesizing available knowledge and research findings, this review enhances our understanding of fire severity's implications for permafrost ecosystems and offers insights into effective fire management strategies.


Assuntos
Ecossistema , Pergelissolo , Solo , Incêndios Florestais , Solo/química , Incêndios , Nitrogênio/análise , Carbono/análise
3.
Plant J ; 107(2): 467-479, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33942410

RESUMO

Association of RNA polymerase V (Pol V) with chromatin is a critical step for RNA- directed DNA methylation (RdDM) in plants. Although the methylated DNA-binding proteins SUVH2 and SUVH9 and the chromatin remodeler-containing complex DRD1-DMS3-RDM1 are known to be required for the association of Pol V with chromatin, the molecular mechanisms underlying the association of Pol V with different chromatin environments remain largely unknown. Here we found that SUVH9 interacts with FVE, a homolog of the mammalian retinoblastoma-associated protein, which has been previously identified as a shared subunit of the histone deacetylase complex and the polycomb-type histone H3K27 trimethyltransferase complex. We demonstrated that FVE facilitates the association of Pol V with chromatin and thus contributes to DNA methylation at a substantial subset of RdDM target loci. Compared with FVE-independent RdDM target loci, FVE-dependent RdDM target loci are more abundant in gene-rich chromosome arms than in pericentromeric heterochromatin regions. This study contributes to our understanding of how the association of Pol V with chromatin is regulated in different chromatin environments.


Assuntos
Proteínas de Arabidopsis/fisiologia , Cromatina/metabolismo , Metilação de DNA , RNA Polimerases Dirigidas por DNA/metabolismo , Fatores de Transcrição/fisiologia , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Imunoprecipitação , Interferência de RNA , Plântula/metabolismo , Fatores de Transcrição/metabolismo
4.
EMBO J ; 37(19)2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30104406

RESUMO

In eukaryotes, heterochromatin regions are typically subjected to transcriptional silencing. DNA methylation has an important role in such silencing and has been studied extensively. However, little is known about how methylated heterochromatin regions are subjected to silencing. We conducted a genetic screen and identified an epcr (enhancer of polycomb-related) mutant that releases heterochromatin silencing in Arabidopsis thaliana We demonstrated that EPCR1 functions redundantly with its paralog EPCR2 and interacts with PWWP domain-containing proteins (PWWPs), AT-rich interaction domain-containing proteins (ARIDs), and telomere repeat binding proteins (TRBs), thus forming multiple functionally redundant protein complexes named PEAT (PWWPs-EPCRs-ARIDs-TRBs). The PEAT complexes mediate histone deacetylation and heterochromatin condensation and thereby facilitate heterochromatin silencing. In heterochromatin regions, the production of small interfering RNAs (siRNAs) and DNA methylation is repressed by the PEAT complexes. The study reveals how histone deacetylation, heterochromatin condensation, siRNA production, and DNA methylation interplay with each other and thereby maintain heterochromatin silencing.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas/fisiologia , Inativação Gênica/fisiologia , Heterocromatina/metabolismo , Histonas/metabolismo , Complexos Multiproteicos/metabolismo , Acetilação , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Heterocromatina/genética , Histonas/genética , Complexos Multiproteicos/genética
5.
New Phytol ; 233(2): 751-765, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34724229

RESUMO

FLOWERING LOCUS M (FLM) is a well-known MADS-box transcription factor that is required for preventing early flowering under low temperatures in Arabidopsis thaliana. Alternative splicing of FLM is involved in the regulation of temperature-responsive flowering. However, how the basic transcript level of FLM is regulated is largely unknown. Here, we conducted forward genetic screening and identified a previously uncharacterized flowering repressor gene, UBA2c. Genetic analyses indicated that UBA2c represses flowering at least by promoting FLM transcription. We further demonstrated that UBA2c directly binds to FLM chromatin and facilitates FLM transcription by inhibiting histone H3K27 trimethylation, a histone marker related to transcriptional repression. UBA2c encodes a protein containing two putative RNA recognition motifs (RRMs) and one prion-like domain (PrLD). We found that UBA2c forms speckles in the nucleus and that both the RRMs and PrLD are required not only for forming the nuclear speckles but also for the biological function of UBA2c. These results identify a previously unknown flowering repressor and provide insights into the regulation of flowering time.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Flores/fisiologia , Regulação da Expressão Gênica de Plantas , Proteínas de Domínio MADS/genética , Proteínas de Domínio MADS/metabolismo , Motivo de Reconhecimento de RNA
6.
J Integr Plant Biol ; 64(4): 901-914, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35043580

RESUMO

Although two Enhancer of Polycomb-like proteins, EPL1A and EPL1B (EPL1A/B), are known to be conserved and characteristic subunits of the NuA4-type histone acetyltransferase complex in Arabidopsis thaliana, the biological function of EPL1A/B and the mechanism by which EPL1A/B function in the complex remain unknown. Here, we report that EPL1A/B are required for the histone acetyltransferase activity of the NuA4 complex on the nucleosomal histone H4 in vitro and for the enrichment of histone H4K5 acetylation at thousands of protein-coding genes in vivo. Our results suggest that EPL1A/B are required for linking the NuA4 catalytic subunits HISTONE ACETYLTRANSFERASE OF THE MYST FAMILY 1(HAM1) and HAM2 with accessory subunits in the NuA4 complex. EPL1A/B function redundantly in regulating plant development especially in chlorophyll biosynthesis and de-etiolation. The EPL1A/B-dependent transcription and H4K5Ac are enriched at genes involved in chlorophyll biosynthesis and photosynthesis. We also find that EAF6, another characteristic subunit of the NuA4 complex, contributes to de-etiolation. These results suggest that the Arabidopsis NuA4 complex components function as a whole to mediate histone acetylation and transcriptional activation specifically at light-responsive genes and are critical for photomorphogenesis.


Assuntos
Arabidopsis , Proteínas de Saccharomyces cerevisiae , Acetilação , Arabidopsis/genética , Arabidopsis/metabolismo , Clorofila , Histona Acetiltransferases/genética , Histona Acetiltransferases/metabolismo , Histonas/metabolismo , Fotossíntese/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
7.
Environ Monit Assess ; 194(5): 344, 2022 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-35389092

RESUMO

Tree tissues can accumulate heavy metals from the environment. We therefore aimed to evaluate the presence of the metals Pb, Cr, Mn, Cu, and Zn in four street tree species, namely Ailanthus altissima, Broussonetia papyrifera, Pinus tabuliformis, and Rhus typhina, along the highway side of Beijing, China. Sampling from the leaves, trunk bark, and branch annual segment bark of trees was conducted in the summer of 2021, and the concentration of heavy metals was determined. The results revealed the highest average concentration of total heavy metals in the R. typhina leaves (23.724 mg/kg) and barks (14.454 mg/kg). The maximum bio-concentration factor was noted for Zn in the B. papyrifera leaves (0.36) and P. tabuliformis barks (0.21). The maximum comprehensive bio-concentration index was observed for the B. papyrifera leaves (0.225) and P. tabuliformis bark (0.108). The maximum metal accumulation index was measured in the R. typhina leaves (29.682) and bark (12.407). Based on the air-originated metals, P. tabuliformis showed the highest dust collection capacity. In general, B. papyrifera and P. tabuliformis exhibited the highest absorption rate from the soil relative to the other studied species. R. typhina demonstrated the strongest phytoremediation ability for heavy metal pollution in air. In addition, our results proved that the branch annual segment bark of P. tabuliformis is an excellent record carrier that can be used to monitor heavy metal pollution in a specific time duration in an urban area.


Assuntos
Metais Pesados , Poluentes do Solo , Biodegradação Ambiental , Monitoramento Biológico , China , Cidades , Monitoramento Ambiental/métodos , Metais Pesados/análise , Casca de Planta/química , Folhas de Planta/química , Poluentes do Solo/análise , Árvores
8.
Ecotoxicol Environ Saf ; 208: 111582, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396105

RESUMO

In recent years, heavy metal pollution has caused immeasurable harm to the environment. As an emerging technology, phytoremediation technology has gained a place in the treatment of heavy metal pollution with its unique advantages. This study analyzes the toxic effects of mulberry (Morus alba) seeds, seedling growth and silkworm under heavy metal stress of lead (Pb) and cadmium (Cd), and explore the accumulation and migration of Pb and Cd in the soil-mulberry tree-silkworm system. The main results were as follows: (1) Seed germination and potted seedling experiments were conducted under heavy metal Pb and Cd stresses, and it was found that Pb and Cd had inhibitory effects on mulberry seed germination, growth and photosynthesis of mulberry seedlings, and as the concentration of heavy metals increased, the stronger the inhibitory effect. Moreover, Pb and Cd have a synergistic effect under compound stress. (2) The accumulation and transfer rules of Pb and Cd ions in mulberry were different. The content of Pb in mulberry was root > leaf > stem and the content of Cd was root > stem > leaf. The combined stress promoted the transfer of Pb and Cd from the underground part to the aerial portion of mulberry. (3) The silkworm feeds on mulberry leaves contaminated with heavy metals in this experiment and found that: with the increase of silkworm feeding, the heavy metal content in the silkworm body increased significantly, but the content remained in the silkworm body was less, most of it was excreted with silkworm excrement. Combined stress has no significant effect on the detoxification mechanism of silkworm. It is indispensable to think of the synergistic effect of heavy metals on plants germination when seeds are used for phytoremediation.


Assuntos
Bombyx/fisiologia , Cádmio/toxicidade , Cadeia Alimentar , Chumbo/toxicidade , Morus/fisiologia , Poluentes do Solo/toxicidade , Solo/química , Animais , Biodegradação Ambiental , Cádmio/análise , Cádmio/metabolismo , Frutas/química , Metais Pesados/análise , Fotossíntese , Folhas de Planta/química , Plântula/química , Poluentes do Solo/análise , Poluentes do Solo/metabolismo
9.
PLoS Genet ; 12(5): e1006026, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27171427

RESUMO

The SU(VAR)3-9 homolog SUVH9 and the double-stranded RNA-binding protein IDN2 were thought to be components of an RNA-directed DNA methylation (RdDM) pathway in Arabidopsis. We previously found that SUVH9 interacts with MORC6 but how the interaction contributes to transcriptional silencing remains elusive. Here, our genetic analysis indicates that SUVH2 and SUVH9 can either act in the same pathway as MORC6 or act synergistically with MORC6 to mediate transcriptional silencing. Moreover, we demonstrate that IDN2 interacts with MORC6 and mediates the silencing of a subset of MORC6 target loci. Like SUVH2, SUVH9, and IDN2, other RdDM components including Pol IV, Pol V, RDR2, and DRM2 are also required for transcriptional silencing at a subset of MORC6 target loci. MORC6 was previously shown to mediate transcriptional silencing through heterochromatin condensation. We demonstrate that the SWI/SNF chromatin-remodeling complex components SWI3B, SWI3C, and SWI3D interact with MORC6 as well as with SUVH9 and then mediate transcriptional silencing. These results suggest that the RdDM components are involved not only in DNA methylation but also in MORC6-mediated heterochromatin condensation. This study illustrates how DNA methylation is linked to heterochromatin condensation and thereby enhances transcriptional silencing at methylated genomic regions.


Assuntos
Adenosina Trifosfatases/genética , Proteínas de Arabidopsis/genética , Heterocromatina/genética , Metiltransferases/genética , Transcrição Gênica , Adenosina Trifosfatases/metabolismo , Proteínas de Arabidopsis/metabolismo , Montagem e Desmontagem da Cromatina/genética , Metilação de DNA/genética , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Metiltransferases/metabolismo , RNA de Cadeia Dupla/genética , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo
10.
Environ Microbiol ; 20(7): 2386-2396, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29687609

RESUMO

The importance of assembly processes in shaping biological communities is poorly understood, especially for microbes. Here, we report on the forces that structure soil bacterial communities along a 2000 m elevational gradient. We characterized the relative importance of habitat filtering and competition on phylogenetic structure and turnover in bacterial communities. Bacterial communities exhibited a phylogenetically clustered pattern and were more clustered with increasing elevation. Biotic factors (i.e., relative abundance of dominant bacterial lineages) appeared to be most important to the degree of clustering, evidencing the role of the competitive ability of entire clades in shaping the communities. Phylogenetic turnover showed the greatest correlation to elevation. After controlling the elevation, biotic factors showed greater correlation to phylogenetic turnover than all the habitat variables (i.e., climate, soil and vegetation). Structural equation modelling also identified that elevation and soil organic matter exerted indirect effects on phylogenetic diversity and turnover by determining the dominance of microbial competitors. Our results suggest that competition among bacterial taxa induced by soil carbon contributes to the phylogenetic pattern across elevational gradient in the Tibetan Plateau. This highlights the importance of considering not only abiotic filtering but also biotic interactions in soil bacterial communities across stressful elevational gradients.


Assuntos
Bactérias/classificação , Microbiologia do Solo , Fenômenos Fisiológicos Bacterianos , Clima , Ecossistema , Microbiota , Filogenia , Solo
11.
J Integr Plant Biol ; 60(5): 362-368, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29314758

RESUMO

LHP1 mediates recruitment of the PRC2 histone methyltransferase complex to chromatin and thereby facilitates maintenance of H3K27me3 on FLC, a key flowering repressor gene. Here, we report that the PWWP domain proteins (PDPs) interact with FVE and MSI5 to suppress FLC expression and thereby promote flowering. We demonstrated that FVE, MSI5, and PDP3 were co-purified with LHP1. The H3K27me3 level on FLC was decreased in the pdp mutants as well as in the fve/msi5 double mutant. This study suggests that PDPs function together with FVE and MSI5 to regulate the function of the PRC2 complex on FLC.


Assuntos
Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Flores/fisiologia , Histonas/metabolismo , Proteínas de Domínio MADS/metabolismo , Arabidopsis/genética , Arabidopsis/fisiologia , Metilação , Domínios Proteicos , Fatores de Tempo
12.
EMBO J ; 32(8): 1128-40, 2013 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-23524848

RESUMO

DNA methylation in transposons and other DNA repeats is conserved in plants as well as in animals. In Arabidopsis thaliana, an RNA-directed DNA methylation (RdDM) pathway directs de novo DNA methylation. We performed a forward genetic screen for suppressors of the DNA demethylase mutant ros1 and identified a novel Zinc-finger and OCRE domain-containing Protein 1 (ZOP1) that promotes Pol IV-dependent siRNA accumulation, DNA methylation, and transcriptional silencing. Whole-genome methods disclosed the genome-wide effects of zop1 on Pol IV-dependent siRNA accumulation and DNA methylation, suggesting that ZOP1 has both RdDM-dependent and -independent roles in transcriptional silencing. We demonstrated that ZOP1 is a pre-mRNA splicing factor that associates with several typical components of the splicing machinery as well as with Pol II. Immunofluorescence assay revealed that ZOP1 overlaps with Cajal body and is partially colocalized with NRPE1 and DRM2. Moreover, we found that the other development-defective splicing mutants tested including mac3a3b, mos4, mos12 and mos14 show defects in RdDM and transcriptional silencing. We propose that the splicing machinery rather than specific splicing factors is involved in promoting RdDM and transcriptional silencing.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Metilação de DNA , DNA/metabolismo , Regulação da Expressão Gênica , RNA/metabolismo , Transcrição Gênica , Arabidopsis/genética , RNA Polimerases Dirigidas por DNA/metabolismo , RNA Polimerase II/metabolismo , Splicing de RNA
13.
PLoS Genet ; 10(1): e1003948, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24465213

RESUMO

RNA-directed DNA methylation (RdDM) is required for transcriptional silencing of transposons and other DNA repeats in Arabidopsis thaliana. Although previous research has demonstrated that the SET domain-containing SU(VAR)3-9 homologs SUVH2 and SUVH9 are involved in the RdDM pathway, the underlying mechanism remains unknown. Our results indicated that SUVH2 and/or SUVH9 not only interact with the chromatin-remodeling complex termed DDR (DMS3, DRD1, and RDM1) but also with the newly characterized complex composed of two conserved Microrchidia (MORC) family proteins, MORC1 and MORC6. The effect of suvh2suvh9 on Pol IV-dependent siRNA accumulation and DNA methylation is comparable to that of the Pol V mutant nrpe1 and the DDR complex mutant dms3, suggesting that SUVH2 and SUVH9 are functionally associated with RdDM. Our CHIP assay demonstrated that SUVH2 and SUVH9 are required for the occupancy of Pol V at RdDM loci and facilitate the production of Pol V-dependent noncoding RNAs. Moreover, SUVH2 and SUVH9 are also involved in the occupancy of DMS3 at RdDM loci. The putative catalytic active site in the SET domain of SUVH2 is dispensable for the function of SUVH2 in RdDM and H3K9 dimethylation. We propose that SUVH2 and SUVH9 bind to methylated DNA and facilitate the recruitment of Pol V to RdDM loci by associating with the DDR complex and the MORC complex.


Assuntos
Proteínas de Arabidopsis/genética , Montagem e Desmontagem da Cromatina/genética , RNA Polimerases Dirigidas por DNA/genética , Histona-Lisina N-Metiltransferase/genética , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Metilação de DNA/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Estrutura Terciária de Proteína/genética , RNA/genética , RNA Interferente Pequeno/genética , RNA não Traduzido/genética
14.
Wei Sheng Yan Jiu ; 46(1): 113-119, 2017 Jan.
Artigo em Zh | MEDLINE | ID: mdl-29903163

RESUMO

OBJECTIVE: Effects of boron( B) on the serum biochemical index and microstructure of immune organs in male obese rats were studied. METHODS: 40 male SD rats( 3-month old) were divided into five groups: normal control group, high-fat-diet control group and boron supplemental group of low, medium and high dose, randomly. The normal control group were fed with normal diet, the other 4 groups were fed with highfat diet to establish the model of obesity for 8 weeks. The boron supplemental group of low, medium and high dose were supplemented 20, 40 and 80 mg B / L in drinking water for 90 d, respectively. At the end, the rats were anesthetized and bled. The blood were collected from right atrium to detected the biochemical indexes related to liver function, and the thymus and spleen were obtained to weighted and fixed, then the samples were made into paraffin sections, stained with hematoxylin-eosin( HE) stain, observed and measured the histological parameters of immune organs. RESULTS: Compared with normal control group, the Lee's index and abdominal fat rate, the level of serum low density lipoprotein cholesterol( LDL-c) and the thymus weight were significantly increased( P <0. 05), but the level of serum total protein( TP) and high density lipoprotein cholesterol( HDL-c) were significantly decreased( P < 0. 05) in high-fat-diet control group, 40 mg /L and 80 mg / L supplement groups of boron. However, these detection indexes did not change significantly( P > 0. 05) in 20 mg / L supplement groups of boron. Compared with the high-fat-diet control group, the Lee's index and abdominal fat rate, the level of serum Apolipoprotein B( apo B) and LDL-c, the thymus weight and index were significantly decreased( P < 0. 05), but the level of serum TP and high density lipoprotein cholesterol( HDL-c) were significantly increased( P < 0. 05) in 20 mg /L supplement groups of boron. The level of serum LDL-c and thymus weight was significantly lower( P < 0. 05) in40 mg / L supplement groups of boron. But all the above detection indicators did not change significantly( P > 0. 05) in 80 mg / L supplement groups of boron. Under the microscope, compared with high-fat-diet control group, splenic nodule area was increased significantly( P < 0. 05), splenic periarterial lymphatic sheath, marginal zone and splenic cord were also thicker significantly( P < 0. 05), thymus medulla / cortex ratio decreased significantly( P < 0. 05), the cells arranged closely, vacuolar like structures were less in the thymus medulla of 20 mg / L and 40 mg / L supplement groups of boron. Microstructure of spleen and thymus did not change significantly in 80 mg / L supplement groups of boron. CONCLUSION: Supplementation of 20 mg B / L could decrease the level of serum apo B and LDL-c, and increase the level of serum HDL-c, and protect the liver function and immune organ of rat from damage caused obese by high fat diet.


Assuntos
Boro/farmacologia , Dieta Hiperlipídica , Obesidade/sangue , Animais , HDL-Colesterol , Suplementos Nutricionais , Água Potável , Masculino , Ratos , Ratos Sprague-Dawley
15.
Nucleic Acids Res ; 41(18): 8489-502, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23877244

RESUMO

DNA methylation is a conserved epigenetic marker in plants and animals. In Arabidopsis, DNA methylation can be established through an RNA-directed DNA methylation (RdDM) pathway. By screening for suppressors of ros1, we identified STA1, a PRP6-like splicing factor, as a new RdDM regulator. Whole-genome bisulfite sequencing suggested that STA1 and the RdDM pathway share a large number of common targets in the Arabidopsis genome. Small RNA deep sequencing demonstrated that STA1 is predominantly involved in the accumulation of the siRNAs that depend on both Pol IV and Pol V. Moreover, the sta1 mutation partially reduces the levels of Pol V-dependent RNA transcripts. Immunolocalization assay indicated that STA1 signals are exclusively present in the Cajal body and overlap with AGO4 in most nuclei. STA1 signals are also partially overlap with NRPE1. Localization of STA1 to AGO4 and NRPE1 signals is probably related to the function of STA1 in the RdDM pathway. Based on these results, we propose that STA1 acts downstream of siRNA biogenesis and facilitates the production of Pol V-dependent RNA transcripts in the RdDM pathway.


Assuntos
Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/fisiologia , Arabidopsis/genética , Metilação de DNA , RNA Polimerases Dirigidas por DNA/metabolismo , Proteínas Nucleares/fisiologia , RNA Interferente Pequeno/biossíntese , Proteínas de Arabidopsis/análise , Proteínas de Arabidopsis/genética , Proteínas Argonautas/análise , Corpos Enovelados/química , Corpos Enovelados/enzimologia , RNA Polimerases Dirigidas por DNA/análise , Inativação Gênica , Genoma de Planta , Mutação , Proteínas Nucleares/análise , Proteínas Nucleares/genética , Pequeno RNA não Traduzido/biossíntese
16.
PLoS Genet ; 8(5): e1002693, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22570638

RESUMO

IDN2/RDM12 has been previously identified as a component of the RNA-directed DNA methylation (RdDM) machinery in Arabidopsis thaliana, but how it functions in RdDM remains unknown. By affinity purification of IDN2, we co-purified two IDN2 paralogs IDP1 and IDP2 (IDN2 PARALOG 1 and 2). The coiled-coil domain between the XS and XH domains of IDN2 is essential for IDN2 homodimerization, whereas the IDN2 C-terminal XH domain but not the coiled-coil domain is required for IDN2 interaction with IDP1 and IDP2. By introducing the wild-type IDN2 sequence and its mutated derivatives into the idn2 mutant for complementation testing, we demonstrated that the previously uncharacterized IDN2 XH domain is required for the IDN2-IDP1/IDP2 complex formation as well as for IDN2 function. IDP1 is required for de novo DNA methylation, siRNA accumulation, and transcriptional gene silencing, whereas IDP2 has partially overlapping roles with IDP1. Unlike IDN2, IDP1 and IDP2 are incapable of binding double-stranded RNA, suggesting that the roles of IDP1 and IDP2 are different from those of IDN2 in the IDN2-IDP1/IDP2 complex and that IDP1 and IDP2 are essential for the functioning of the complex in RdDM.


Assuntos
Proteínas de Arabidopsis , Arabidopsis/genética , Metilação de DNA/genética , Complexos Multiproteicos , Proteínas de Ligação a RNA , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/isolamento & purificação , Proteínas de Arabidopsis/metabolismo , Complexos Multiproteicos/genética , Complexos Multiproteicos/metabolismo , Estrutura Terciária de Proteína , RNA/genética , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/isolamento & purificação , Proteínas de Ligação a RNA/metabolismo , Homologia de Sequência de Aminoácidos
17.
ScientificWorldJournal ; 2014: 923610, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24693254

RESUMO

Obligate aerobic AMF taxa have high species richness under waterlogged conditions, but their ecological role remains unclear. Here we focused on AM fungal mediation of plant interactions in a marshland plant community. Five cooccurring plant species were chosen for a neighbor removal experiment in which benomyl was used to suppress AMF colonization. A Phragmites australis removal experiment was also performed to study its role in promoting AMF colonization by increasing rhizosphere oxygen concentration. Mycorrhizal fungal effects on plant interactions were different for dominant and subdominant plant species. AMF colonization has driven positive neighbor effects for three subdominant plant species including Kummerowia striata, Leonurus artemisia, and Ixeris polycephala. In contrast, AMF colonization enhanced the negative effects of neighbors on the dominant Conyza canadensis and had no significant impact on the neighbor interaction to the dominant Polygonum pubescens. AM colonization was positively related to oxygen concentration. P. australis increased oxygen concentration, enhanced AMF colonization, and was thus indirectly capable of influencing plant interactions. Aerobic AM fungi appear to be ecologically relevant in this wetland ecosystem. They drive positive neighbor interactions for subdominant plant species, effectively increasing plant diversity. We suggest, therefore, that AM fungi may be ecologically important even under waterlogged conditions.


Assuntos
Magnoliopsida/microbiologia , Micorrizas/fisiologia , Áreas Alagadas , Magnoliopsida/fisiologia
18.
Anat Histol Embryol ; 53(3): e13042, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38634511

RESUMO

To observe developmental changes in the ovarian tissue structure and distribution characteristics of oestrogen receptors (ERs) in the ovaries of Huanghuai goats at different ages, we selected healthy Huanghuai goats ewes and divided them into five groups (i.e. 3-, 30-, 60-, 90- and 120-day-old groups), with 10 animals in each group. The serum was separated after blood collection through the jugular vein, and the contents of oestrogen (E) and progesterone (P) in the serum of Huanghuai goats at each age were determined. Three goats were randomly selected from each group and sacrificed after anaesthesia, and the ovarian tissue was quickly obtained and placed in 4% paraformaldehyde fixative to prepare the tissue sections. Using HE, oestrogen receptors were immunohistochemically stained and observed. These results showed many primordial follicles and occasional secondary follicles in the ovaries of 3-day-old Huanghuai goats. Ovarian reticular structures were observed in 30-day-old ovarian medulla, with occasional near-mature growing follicles. Mature follicles and corpus luteum were occasionally detected in 60-day-old ovarian cortex. The 90-120-day-old ovarian cortices contained growing and mature follicles, and the number of mature follicles and corpora lutea increased, implying a significant luteal involution period. The E and P contents in the 120-day-old group were significantly higher than those in the 3-, 30-, 60- and 90-day-old groups. The levels of ERα and ERß in the 3- and 30-day-old groups were mainly distributed in the granulosa cells of ovarian reproductive epithelial cells, primordial follicles, atretic follicles, and primary and secondary follicles. The ERα and ERß levels of the 60-, 90- and 120-day-old groups were also distributed in the granulosa cells and luteal cells of mature follicles, especially in the 120-day-old endometrial cells of mature follicles, where ERß was distributed significantly. The overall expression of ERß in the ovary was higher than that of ERα. The results of this study provide basic data on the ovarian development and the specific expression of ERs and PRs in the ovaries of Huanghuai white goats, which play an important role in ovarian development and precocity.


Assuntos
Ovário , Receptores de Estrogênio , Feminino , Animais , Ovinos , Ovário/metabolismo , Receptores de Estrogênio/análise , Receptores de Estrogênio/metabolismo , Receptor alfa de Estrogênio/análise , Receptor beta de Estrogênio , Cabras/metabolismo
19.
Trends Biotechnol ; 42(1): 91-103, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37507294

RESUMO

Single cell modification or hybridization technology has become a popular direction in bioengineering in recent years, with applications in clean energy, environmental stewardship, and sustainable human development. Here, we draw attention to nanoarmor, a representative achievement of cytoprotection and functionalization technology. The fundamental principles of nanoarmor need to be studied with input from multiple disciplines, including biology, chemistry, and material science. In this review, we explain the role of nanoarmor and review progress in its applications. We also discuss three main challenges associated with its development: self-driving ability, heterojunction characteristics, and mineralization formation. Finally, we propose a preliminary classification system for nanoarmor.


Assuntos
Citoproteção , Nanotecnologia , Humanos
20.
Biology (Basel) ; 13(7)2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-39056675

RESUMO

Oncomelania hupensis is the exclusive intermediary host of Schistosoma japonicum in China. The alteration of O. hupensis habitat and population distribution directly affects the safety of millions of individuals residing in the Yangtze River Economic Belt (YREB) and the ecological stability of Yangtze River Basin. Therefore, it is crucial to analyze the influence of climate change on the distribution of O. hupensis in order to achieve accurate control over its population. This study utilized the MaxEnt model to forecast possible snail habitats by utilizing snail distribution data obtained from historical literature. The following outcomes were achieved: The primary ecological factors influencing the distribution of O. hupensis are elevation, minimum temperature of the coldest month, and precipitation of wettest month. Furthermore, future climate scenarios indicate a decrease in the distribution area and a northward shift of the distribution center for O. hupensis; specifically, those in the upstream will move northeast, while those in the midstream and downstream will move northwest. These changes in suitable habitat area, the average migration distance of distribution centers across different climate scenarios, time periods, and sub-basins within the YREB, result in uncertainty. This study offers theoretical justification for the prevention and control of O. hupensis along the YREB.

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