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1.
Plant Biotechnol J ; 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33932077

RESUMO

RNase P functions either as a catalytic ribonucleoprotein (RNP) or as an RNA-free polypeptide to catalyze RNA processing, primarily tRNA 5' maturation. To the growing evidence of non-canonical roles for RNase P RNP subunits including regulation of chromatin structure and function, we add here a role for the rice RNase P Rpp30 in innate immunity. This protein (encoded by LOC_Os11g01074) was uncovered as the top hit in yeast two-hybrid assays performed with the rice histone deacetylase HDT701 as bait. We showed that HDT701 and OsRpp30 are localized to the rice nucleus, OsRpp30 expression increased post-infection by Pyricularia oryzae (syn. Magnaporthe oryzae), and OsRpp30 deacetylation coincided with HDT701 overexpression in vivo. Overexpression of OsRpp30 in transgenic rice increased expression of defense genes and generation of reactive oxygen species after pathogen-associated molecular pattern elicitor treatment, outcomes that culminated in resistance to a fungal (P. oryzae) and a bacterial (Xanthomonas oryzae pv. oryzae) pathogen. Knockout of OsRpp30 yielded the opposite phenotypes. Moreover, HA-tagged OsRpp30 co-purified with RNase P pre-tRNA cleavage activity. Interestingly, OsRpp30 is conserved in grass crops, including a near-identical C-terminal tail that is essential for HDT701 binding and defense regulation. Overall, our results suggest that OsRpp30 plays an important role in rice immune response to pathogens, and provide a new approach to generate broad-spectrum disease-resistant rice cultivars.

2.
Nutrients ; 13(5)2021 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-33922242

RESUMO

As a natural active substance that can effectively improve blood lipid balance in the body, hypolipidemic active peptides have attracted the attention of scholars. In this study, the effect of walnut meal peptides (WMP) on lipid metabolism was investigated in rats fed a high-fat diet (HFD). The experimental results show that feeding walnut meal peptides counteracted the high-fat diet-induced increase in body, liver and epididymal fat weight, and reduce the serum concentrations of total cholesterol, triglycerides, and LDL-cholesterol and hepatic cholesterol and triglyceride content. Walnut meal peptides also resulted in increased HDL-cholesterol while reducing the atherosclerosis index (AI). Additionally, the stained pathological sections of the liver showed that the walnut meal peptides reduced hepatic steatosis and damage caused by HFD. Furthermore, walnut meal peptide supplementation was associated with normalization of elevated apolipoprotein (Apo)-B and reduced Apo-A1 induced by the high-fat diet and with favorable changes in the expression of genes related to lipid metabolism (LCAT, CYP7A1, HMGR, FAS). The results indicate that walnut meal peptides can effectively prevent the harmful effects of a high-fat diet on body weight, lipid metabolism and liver fat content in rats, and provide, and provide a reference for the further development of walnut meal functional foods.

3.
Hum Genomics ; 15(1): 24, 2021 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-33892795

RESUMO

OBJECTIVE: The occurrence of osteoarthritis is related to genetic and environmental factors. Among them, the change of chondrocyte gene expression pattern regulated by epigenetic modification is an important participant. This study analyzed the effect of CAMP gene methylation on the level of oxidative stress and inflammation of chondrocytes. METHODS: We analyzed the changes of the transcriptome in the articular cartilage tissue of osteoarthritis (OA) patients from the GSE117999 dataset. The GSE48422 dataset was used to analyze the changes in the methylation level of osteoarthritis cells. Cell Counting Kit-8 (CCK-8) and flow cytometry analysis of short hairpin RNA (shRNA) silencing CAMP gene and 5-µM 5-Aza-2'-Deoxycytidine (AZA) treatment on the proliferation and apoptosis of Human chondrocytes osteoarthritis (HC-OA) cells. The Dichloro-dihydro-fluorescein diacetate (DCFH-DA) assay was used to detect the level of reactive oxygen species (ROS), and the expression level of inflammatory factors was analyzed by Western Blot. RESULTS: The expression of CAMP in cartilage tissue of OA patients was upregulated, and the level of methylation was downregulated. CAMP was highly expressed in osteoarthritis articular cartilage cells. Silencing CAMP inhibited the proliferation of HC-OA cells and promoted their apoptosis. CAMP gene methylation inhibited ROS levels and tumor necrosis factor-α (TNF-α) expression levels in HC-OA cells, and promoted transforming growth factor beta (TGF-ß) expression. CAMP gene methylation inhibited the proliferation of HC-OA cells and promoted their apoptosis. CONCLUSION: CAMP gene promoter methylation inhibits ROS levels and inflammation and induces chondrocyte apoptosis.

4.
BMC Genomics ; 22(1): 242, 2021 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-33827423

RESUMO

BACKGROUND: Plant pathogenic isolates of Rhizoctonia solani anastomosis group 1-intraspecific group IA (AG1-IA) infect a wide range of crops causing diseases such as rice sheath blight (ShB). ShB has become a serious disease in rice production worldwide. Additional genome sequences of the rice-infecting R. solani isolates from different geographical regions will facilitate the identification of important pathogenicity-related genes in the fungus. RESULTS: Rice-infecting R. solani isolates B2 (USA), ADB (India), WGL (India), and YN-7 (China) were selected for whole-genome sequencing. Single-Molecule Real-Time (SMRT) and Illumina sequencing were used for de novo sequencing of the B2 genome. The genomes of the other three isolates were then sequenced with Illumina technology and assembled using the B2 genome as a reference. The four genomes ranged from 38.9 to 45.0 Mbp in size, contained 9715 to 11,505 protein-coding genes, and shared 5812 conserved orthogroups. The proportion of transposable elements (TEs) and average length of TE sequences in the B2 genome was nearly 3 times and 2 times greater, respectively, than those of ADB, WGL and YN-7. Although 818 to 888 putative secreted proteins were identified in the four isolates, only 30% of them were predicted to be small secreted proteins, which is a smaller proportion than what is usually found in the genomes of cereal necrotrophic fungi. Despite a lack of putative secondary metabolite biosynthesis gene clusters, the rice-infecting R. solani genomes were predicted to contain the most carbohydrate-active enzyme (CAZyme) genes among all 27 fungal genomes used in the comparative analysis. Specifically, extensive enrichment of pectin/homogalacturonan modification genes were found in all four rice-infecting R. solani genomes. CONCLUSION: Four R. solani genomes were sequenced, annotated, and compared to other fungal genomes to identify distinctive genomic features that may contribute to the pathogenicity of rice-infecting R. solani. Our analyses provided evidence that genomic conservation of R. solani genomes among neighboring AGs was more diversified than among AG1-IA isolates and the presence of numerous predicted pectin modification genes in the rice-infecting R. solani genomes that may contribute to the wide host range and virulence of this necrotrophic fungal pathogen.

5.
Plant Biol (Stuttg) ; 2021 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-33884732

RESUMO

Salt is among the most harmful agents that negatively influence crop yield. Developing salt tolerant plants is a promising way to utilize salinized lands. Alfalfa is an important perennial forage crop that exhibits wide cultivar variations in salt tolerance. A comprehensive method was developed to achieve the reliable and effective evaluation of alfalfa salt resistance. It included principal component, membership functions, and cluster and stepwise regression analysis. It was used to analyze the salt tolerant coefficients of 14 traits and to evaluate the 20 diverse alfalfa cultivars at seedling stage. According to the comprehensive evaluation value (D value), one high salt tolerant, two salt tolerant, four moderately salt tolerant, and 13 salt sensitive alfalfa cultivars were screened. Then, a mathematical equation for the evaluation of alfalfa salt tolerance was established, as follows: D'= -0.126+0.667SFW+0.377SDW+1.089K+ /Na+ +0.172SFW/RFW (R2 = 0.988; average forecast accuracy was 96.95%), where four indices were closely related to the salt-tolerance, including shoot fresh weight, ratio of shoot fresh weight to root fresh weight, shoot dry weight, and ratio of K+ to Na+ in shoot. The various morphological root parameters of six alfalfa cultivars with contrasting salt tolerance were tested at seedling stage under different NaCl concentrations. SSA correlated strongly with SFW, SDW, K+ /Na+ , D values, and SRV correlated obviously with SFW, SFW/RFW and D values at 150 mM NaCl treatment. In conclusion, the SFW, K+ /Na+ , SDW, SFW/RFW, SSA and SRV could be used as indicators of salt tolerance in alfalfa seedlings under 150 mM NaCl treatment.

6.
BMC Musculoskelet Disord ; 22(1): 329, 2021 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-33812379

RESUMO

BACKGROUND: Animal model of Knee Osteoarthritis (OA) is the primary testing methodology for studies on pathogenic mechanisms and therapies of human OA disease. Recent major modeling methods are divided into artificially induced and spontaneous. However, these methods have some disadvantages of slow progression, high cost and no correlation with the pathogenesis of OA. METHODS: Our studies attempted to find a rapid, easy, and consistent with the natural pathological process of OA modeling method by intra-articular injection of stromal cell-derived factor 1 (SDF-1) in the rabbit knee. After induction we collected cartilage specimens from the medial femoral condyle to undergo macroscopic, histological, immunohistochemical, and biochemical evaluations. Meanwhile, compared with Hulth surgical method to evaluate its efficacy. RESULTS: Macroscopic observation and modified Mankin score of histological staining exhibited typical features of middle stage OA cartilage in SDF-1 injected groups. Immunohistochemically, the positive expression of interleukin-1 (IL-1) and tumor necrosis factor α(TNF-α) was earlier and higher in high dose SDF-1 group than the surgical group. The matrix metalloproteinases (MMPs) in synovial fluid and chondrocytes significantly increased, but type II collagen (COLII) and aggrecan (ACAN) protein expressions decreased in SDF-1 injected group following the extension of time and increase of SDF-1 concentration. CONCLUSIONS: Our data indicated intra-articular injection of SDF-1 (40µg/kg, three times for 12 weeks) can induce rabbit knee OA model successfully more rapidly and easily than traditional surgical modeling. The study provided a further option for the establishment of knee OA animal model.

7.
Int J Biol Macromol ; 182: 879-898, 2021 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-33857511

RESUMO

High-fat (HF) diets cause obesity, gut microbial dysbiosis and associated disorders and inflammatory bowel disease (IBD) due to increased intestinal permeability, which is an important reason for chronic inflammation and oxidative stress. This study was to investigate the effects and mechanism by which walnut green husk polysaccharides (WGHP) prevents obesity, oxidative stress, inflammation, liver and colon damage in HF diet induced rats. We found that WGHP alleviated HF-induced abnormal weight gain, disordered lipid metabolism, inflammation, oxidative stress, colonic tissue injury and up-regulate the expression level of colonic tight junction protein in the rats. Besides, the administration of WGHP promoted browning of iWAT and thermogenesis in BAT of HF-fed rats, and improved gut microbiota dysbiosis by increasing the bacterial diversity and reducing the relative abundance of potential pathogenic bacteria in the colon of the rats. Furthermore, WGHP consumption not only increased the SCFAs content but also improved the relative abundance of Prevotellaceae and Allobaculum in the gut of rats. Our results suggest that the protective effect of WGHP on metabolic inflammation caused by HF may be due to the regulation of gut microbiota and SCFAs.

8.
Phys Chem Chem Phys ; 23(11): 6871-6879, 2021 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-33725032

RESUMO

The electronic transport properties of in-plane graphene/MoS2/graphene heterojunctions are studied using density functional theory and the nonequilibrium Green's function method. It is found that different covalent bond connections cause different electron distributions, such as accumulation or depletion, on the contact surface. The C-S structure exhibits more electron accumulation and depletion, indicating that the electrons can easily transfer from MoS2 to graphene. Since the three structures all form covalent or ionic bonds, the tunneling barrier for carriers is very small. The C-S structure exhibits a smaller p-type Schottky barrier, indicating that it has better transport properties than the other two structures. We found that the effective doping method can reduce the Schottky-barrier height (SBH), resulting in smaller contact resistance. Thus, the current-voltage curves of the undoped and doped C-S structures exhibit rectification and approximately linear characteristics under a given bias, which agrees with experimental reports. These results provide insight for designing high-performance devices.

10.
Endocr Relat Cancer ; 28(4): 247-255, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33690161

RESUMO

It is uncertain whether serum TSH concentration is an independent risk factor for the malignancy of pediatric thyroid nodules. We sought the association of serum TSH concentration with the malignancy of pediatric thyroid nodules and with the characteristics of pediatric thyroid cancer. A total of 219 pediatric thyroid nodule patients were collected retrospectively for 5 consecutive years. The medical records collected included sex, age, serum TSH concentration, thyroid autoantibody status, thyroid ultra-sonography parameters, histological type, and pathological TNM stages. The serum TSH concentrations were compared between benign and malignant nodules or corresponding subgroups. Binary logistic regression analysis was used to evaluate the correlation of TSH concentration with the malignancy of thyroid nodules and with the characteristics of pediatric thyroid cancer. There was no significant difference in TSH concentration between benign nodule and thyroid cancer in total subjects and various subgroups. The serum TSH level was not correlated with the malignancy of thyroid nodules in univariate analysis, but negatively correlated with the malignancy of thyroid nodules (odds ratio = 0.856, P = 0.013) after adjusting for the patients' sex, age, thyroid autoantibody status, and nodule size. The serum TSH level was not correlated with the tumor characteristics in pediatric thyroid cancer patients. In conclusion, the serum TSH concentration seems not to be a carcinogenic factor in pediatric thyroid nodule patients, nor to be an independent risk factor for characteristics of pre-existing pediatric thyroid cancers.

11.
Biomed Res Int ; 2021: 6693906, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33748280

RESUMO

Background: Longbone infected bone defect remains a great challenge due to multiple surgeries, long-term treatment duration, and uncertain prognosis. Treatment principles include eradication/debridement, stabilization, and antibiotic administration. An antibiotic cement-coated nail has shown great prospects due to both local antibiotic elution and stabilization of bone defects. However, the current fabrication technique remains to be improved. Methods: For the first time, we described a new method for custom-made cement-coated nail fabrication based on a 3D printing technique. A retrospective study of 19 consecutive patients with long bone infected bone defects from one medical center was conducted who met the inclusion and exclusion criteria from November 2016 to May 2020. The treatment involved thorough debridement, custom-made antibiotic cement-coated nail filling, and culture-specific systemic antibiotic treatment guided by a multidisciplinary team. Clinical and radiographic examinations (X-ray and CT scans) were used to evaluate bony union. Clinical and laboratory examinations were used to evaluate the infection control. The SF-36 score was used to evaluate patients' quality of life pre- and postoperatively. Results: The mean follow-up was 98.8 weeks (ranging from 40 to 192). All cases achieved infection control, 3 cases achieved bone healing after one-stage operation, and 12 cases achieved bone healing after a two-stage bone graft procedure. At the last follow-up, none of the 19 patients had infection recurrence or 1 case had failure of the protective plate. The pre- and postoperative SF-36 score showed that there were statistical differences in all the 9 aspects. Conclusions: The precise custom-made antibiotic cement-coated intramedullary nail through the 3D printing technique used in this study is an effective strategy for the treatment of infected bone defects of long bone. This technique may help to increase the infection control rate and promote bone healing.

12.
Med Sci Monit ; 27: e932375, 2021 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-33762569

RESUMO

An editorial decision has been made to retract this manuscript due to breach of publishing guidelines, following the identification of non-original and manipulated figures. Reference: Jun Liu, Yan Liu, Yan Liu, Lei Huang, Guoliang Wang, Jun Wang, Xiangang Xu, Chengxian Shi, Jianzhao Huang: Anticancer Action of Psilostachyin-A in 5-Fluorouracil-Resistant Human Liver Carcinoma are Mediated Through Autophagy Induction, G2/M Phase Cell Cycle Arrest and Inhibiting Extracellular-Signal-Regulated Kinase/Mitogen Activated Protein Kinase (ERK/MAPK) Signaling Pathway. Med Sci Monit 2019; 25:6711-6718. 10.12659/MSM.916635.

13.
J Immunother Cancer ; 9(3)2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33753568

RESUMO

BACKGROUND: The satisfactory prognostic indicator of gastric cancer (GC) patients after surgery is still lacking. Perioperative plasma extracellular vesicular programmed cell death ligand-1 (ePD-L1) has been demonstrated as a potential prognosis biomarker in many types of cancers. The prognostic value of postoperative plasma ePD-L1 has not been characterized. METHODS: We evaluated the prognostic value of preoperative, postoperative and change in plasma ePD-L1, as well as plasma soluble PD-L1, in short-term survival of GC patients after surgery. The Kaplan-Meier survival model and Cox proportional hazards models for both univariate and multivariate analyzes were used. And the comparison between postoperative ePD-L1 and conventional serum biomarkers (carcinoembryonic antigen (CEA), cancer antigen 19-9 (CA19-9) and CA72-4) in prognostic of GC patients was made. RESULTS: The prognostic value of postoperative ePD-L1 is superior to that of preoperative ePD-L1 on GC patients after resection, and also superior to that of conventional serum biomarkers (CEA, CA19-9 and CA72-4). The levels of postoperative ePD-L1 and ePD-L1 change are independent prognostic factors for overall survival and recurrence free survival of GC patients. High plasma level of postoperative ePD-L1 correlates significantly with poor survival, while high change in ePD-L1 level brings the significant survival benefit. CONCLUSIONS: The level of plasma postoperative ePD-L1 could be considered as a candidate prognostic biomarker of GC patients after resection.

14.
Sci Total Environ ; 780: 146298, 2021 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-33770604

RESUMO

Nitrogen (N) addition has variable effects on chemical composition, function, and turnover of roots with different diameters. However, it is unclear whether N addition has variable effects on greenhouse gas (GHG) emission in rhizosphere soil. We performed N addition (0-9 g N m-2 y-1) experiment in a Pinus tabulaeformis forest and a lab-incubation experiment to determine the effects of N addition on carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4) emissions in rhizosphere soils of roots with different diameters (very fine roots: <0.5 mm, intermediate fine roots: 0.5-1.0 mm, largest fine roots: 1.0-2.0 mm). Nitrogen addition significantly promoted CO2 emission and CH4 uptake, with maximum values (CO2, 623.15 mg C kg soil-1; CH4, 1794.49 µg C kg soil-1) in the 6 or 9 g N m-2 y-1 treatments (P < 0.05). Nitrous oxide emissions were inhibited, with the greatest inhibitory effect in the 9 g N m-2 y-1 treatment (48.63 µg N kg soil-1). Total phosphorus (TP) content significantly decreased and increased in rhizosphere soil and non-rhizosphere soil after N addition, respectively, while organic carbon (OC), total N (TN), ammonium (NH4+), and nitrate (NO3-) contents in rhizosphere soil increased. A greater change in chemical properties occurred in rhizosphere soil of largest fine roots than very fine roots. Carbon dioxide and nitrous oxide emissions in rhizosphere soil among root sizes exhibited similar responses to N addition. While CH4 uptake was more responsive to N addition in rhizosphere soil with very fine roots than with largest fine roots. Basically, OC, TN, NO3-, and NH4+ were key soil components driving GHG emissions; NO3- promoted CH4 uptake and N2O emissions, NH4+ inhibited CO2 emissions. GHG response to N addition varied greatly, particularly in rhizosphere soil with different root sizes mainly related to its chemical properties.

15.
J Reprod Dev ; 67(2): 115-122, 2021 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-33597332

RESUMO

We have studied the mechanisms by which meiotic arrest maintenance (MAM) with roscovitine, female sexual maturity, and the surrounded nucleoli (SN) chromatin configuration improve the competence of mouse oocytes by observing the expression of oocyte competence-related genes in non-surrounded nucleoli (NSN) and SN oocytes from prepubertal and adult mice following maturation with or without MAM. The results demonstrated that MAM with roscovitine significantly improved the developmental potential of adult SN and prepubertal NSN oocytes, but had no effect on that of prepubertal SN oocytes. Without MAM, while 40% of the 2-cell embryos derived from prepubertal SN oocytes developed into 4-cell embryos, none of the 2-cell embryos derived from prepubertal NSN oocytes did, and while 42% of the 4-cell embryos derived from adult SN oocytes developed into blastocysts, only 1% of the 4-cell embryos derived from prepubertal SN oocytes developed into blastocysts. Furthermore, MAM with roscovitine, SN configuration, and female sexual maturity significantly increased the mRNA levels of competence-beneficial genes and decreased those of competence-detrimental genes. In conclusion, our results suggest that MAM with roscovitine, SN chromatin configuration, and female sexual maturity improve oocyte competence by regulating the expression of competence-related genes, suggesting that Oct4, Stella, Mater, Zar1, Mapk8, and Bcl2 are oocyte competence-beneficial genes, whereas Foxj2, Ship1, and Bax are competence-detrimental genes.

16.
Theor Appl Genet ; 134(5): 1303-1317, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33566123

RESUMO

KEY MESSAGE: Based on the high-density variation map, we identified genome-level evidence for local adaptation and demonstrated that Siprr37 with transposon insertion contributes to the fitness of foxtail millet in the northeastern ecoregion. Adaptation is a robust way through which plants are able to overcome environmental constraints. The mechanisms of adaptation in heterogeneous natural environments are largely unknown. Deciphering the genomic basis of local adaptation will contribute to further improvement in domesticated plants. To this end, we describe a high-depth (19.4 ×) haplotype map of 3.02 million single nucleotide polymorphisms in foxtail millet (Setaria italica) from whole-genome resequencing of 312 accessions. In the genome-wide scan, we identified a set of improvement signals (including the homologous gene of OsIPA1, a key gene controlling ideal plant architecture) related to the geographical adaptation to four ecoregions in China. In particular, based on the genome-wide association analysis results, we identified the contribution of a pseudo-response regulator gene, SiPRR37, to heading date adaptation in foxtail millet. We observed the expression changes of SiPRR37 resulted from a key Tc1-Mariner transposon insertion in the first intron. Positive selection analyses revealed that SiPRR37 mainly contributed to the adaptation of northeastern ecoregions. Taken together, foxtail millet adapted to the northeastern region by regulating the function of SiPRR37, which sheds lights on genome-level evidence for adaptive geographical divergence. Besides, our data provide a nearly complete catalog of genomic variation aiding the identification of functionally important variants.

17.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 35(2): 258-264, 2021 Feb 15.
Artigo em Chinês | MEDLINE | ID: mdl-33624484

RESUMO

Objective: To review the research progress of location methods and the best femoral insertion position of medial patellofemoral ligament (MPFL) reconstruction of femoral tunnel, and provide reference for surgical treatment. Methods: The literature about femoral insertion position of the MPFL reconstruction in recent years was extensively reviewed, and the anatomical and biomechanical characteristics of MPFL, as well as the advantages and disadvantages of femoral tunnel positioning methods were summarized. Results: The accurate establishment of the femoral anatomical tunnel is crucial to the success of MPFL reconstruction. At present, there are mainly two kinds of methods for femoral insertion: radiographic landmark positioning method and anatomical landmark positioning method. Radiographic landmark positioning method has such advantages as small incision and simple operation, but it can not be accurately positioned for patients with severe femoral trochlear dysplasia. It is suggested to combine with the anatomical landmark positioning method. These methods have their own advantages and disadvantages, and there is no unified positioning standard. In recent years, the use of three-dimensional design software can accurately assist in the MPFL reconstruction, which has become a new trend. Conclusion: Femoral tunnel positioning of the MPFL reconstruction is very important. The current positioning methods have their own advantages and disadvantages. Personalized positioning is a new trend and has not been widely used in clinic, its effectiveness needs further research and clinical practice and verification.


Assuntos
Doenças Ósseas , Ferida Cirúrgica , Artéria Femoral , Fêmur/cirurgia , Humanos , Ligamentos Articulares/cirurgia
18.
Ying Yong Sheng Tai Xue Bao ; 32(1): 73-81, 2021 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-33477215

RESUMO

In order to explore how water stress affects the stoichiometric characteristics in leaves, stems, very fine roots (0-1 mm), fine roots (1-2 mm) and thick roots (>2 mm) of three shrub species, we studied the effects of three water treatments [(75±5)%, (55±5)% and (35±5)% of field water capacity (FC)] on the stoichiometric characteristics of different organs of Syringa oblata, Rosa xanthina and Forsythia suspensa in a pot experiment. The results showed that there were significant differences in nitrogen (N) and phosphorus (P) contents, C:N, C:P and N:P of the same organ among the three species. With the intensification of drought stress, there was no significant change of C content in all organs of the three species. The N content increased in leaves, but decreased gradually in stems. The N content in very fine roots and fine roots increased first and then decreased. The P content decreased in leaves and stems, while increased first and then decreased in very fine roots and fine roots. Under drought stress, leaf C:N decreased, C:P and N:P of leaf and stem increased. There was the strongest effect of drought stress on the C:N of very fine roots and C:P and N:P of leaves. There was the least effect of drought stress on C:N, N:P of thick roots and C:P of very fine roots. There was no significant correlation between the contents of C, N in soil and the contents of C, N and P in shrub organs, but soil P content was significantly correlated with the contents of C, N and P in leaves and roots. It was concluded that the relative P limitation in soil was the most important factor affecting the stoichiometric characteristics of shrub organs. Drought had different effects on the stoichiometry of different organs in different shrub species. The stoichio-metry of leaves and very fine roots was more sensitive to drought stress than that of other organs. Drought might affect the stoichiometric characteristics especially related to P in different organs of shrubs, mainly by affecting plant absorption of soil P and its distribution in different organs.


Assuntos
Secas , Nitrogênio , Fósforo , Folhas de Planta , Raízes de Plantas , Solo
19.
Sci Total Environ ; 766: 144209, 2021 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-33418253

RESUMO

Sustainable management practices can enhance the capacity and potential for soil carbon (C) sequestration, significantly contributing towards mitigating regional climate change. Here, we investigated how the microbial characteristics of a Pinus tabulaeformis plantation responded to different management practices to identify the role of microbial characteristics in influencing the stability of soil organic carbon (SOC). We chose a Pinus tabulaeformis plantation on the Loess Plateau where forest management practices had been conducted since 1999. Five forest management practices were implemented: two at the forest level (P. tabulaeformis with and without ground litter), and three using different vegetation restoration approaches after clear-cutting (P. tabulaeformis seedlings, abandoned grassland, and natural shrub regeneration). Microbial biomass, soil respiration, microbial community structure, microbial metabolic function, and soil oxidizable organic carbon (OC) fractions were evaluated. Forest management practices changed SOC stability by adjusting the microbial characteristics (e.g. soil microbial community diversity and microbial metabolic function diversity). The result of path analysis was that the direct path coefficient of microbial biomass on soil oxidizable OC fractions was the largest, which was 1.499. Path analysis and redundancy analysis showed that microbial biomass had the largest direct influence on soil oxidizable OC fractions. Compared with other forest management practices, natural shrub regeneration increased the nonlabile carbon fraction by increasing soil microbial characteristics, and contributed the most towards stabilizing SOC, which enhanced the stability of the soil ecosystem on the plateau. In conclusion, microbial biomass was the biggest influence factor of SOC stability. In contrast, the stability of SOC may be most stable in the area of natural shrub regeneration.


Assuntos
Carbono , Pinus , Carbono/análise , China , Ecossistema , Florestas , Solo
20.
Genomics ; 113(1 Pt 1): 265-275, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33326830

RESUMO

Transcriptional re-programming in host and pathogen upon leaf and neck infection is an evolving area of research for the rice blast community. Analysis of in planta rice transcriptome in leaf and neck tissues revealed tissue-specific and infection-specific expression of rice and Magnaporthe oryzae genes in host and pathogen. The glycosyl hydrolase, isocitrate lyase, cupin domain containing protein, TF2, CMPG1, CHIT17 and OsCML14 genes were uniquely expressed in leaf infection. Genes like cytochrome P450, inhibitor I family protein, GSTU6, abscisic stress ripening, and cupin domain containing protein were up-regulated during neck infection. In our microRNA sequencing study, Osa-miR166n-3p was highly expressed in upon Magnaporthe leaf infection, whereas osa-miR1661-3p, osa-miR166n-3p and osa-miR159b were overexpressed in neck infection. Here we report several transcripts being targeted by up and down regulated microRNAs during infection. The putative genes expressed upon infection in leaf and neck could be used in understanding the dual-epidemics of blast disease.

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