Search

Pores and old root‐channels are preferentially used by roots to allow them to penetrate hard soils. However, there are few studies that have accounted for the effects of pore‐rhizosheath on root growth. In this study, we developed an approach by adding the synthetic root exudates using a porous stainless tube with 0.1‐mm micropores through a peristaltic pump to reproduce the rhizosheath around the artificial pore, and investigated the effects of pores with and without rhizosheaths on maize root growth in a dense soil. The results indicated that the artificial rhizosheath was about 2.69 mm wide in the region surrounding the pores. The rhizosheath had a higher content of organic carbon, total nitrogen, and abundance of Actinobacteria than that of the bulk soil. Compared with the artificial macropores, the artificial root‐pores with a rhizosheath increased the opportunities for root utilisation of the pores space, promoting steeper and deeper root growth. It is concluded that the pore‐rhizosheath has a significant impact on root architecture by enhancing root distribution in macropores. Summary statement: There are few studies that have accounted for the effects of pore‐rhizosheath on root growth. This study reported that the artificial root‐pores with a rhizosheath increased the opportunities for maize root utilisation of the pores space, promoting steeper and deeper root growth. [ABSTRACT FROM AUTHOR]

Plant roots release various organic materials that may modify soil structure and affect heat and mass transfer processes. The objective of this study was to determine the effects of a synthetic root exudate (SRE) on penetrometer resistance (PR), thermal conductivity (λ), hydraulic conductivity (k) and evaporation of water in a sandy soil. Soil samples, mixed with either distilled water or the SRE, were packed into columns at a designated bulk density and water content, and incubated for 7 days at 18°C. Soil PR, λ, k and evaporation rate were monitored during drying processes. Compared with those incubated with water, samples incubated with SRE had visible hyphae, greater PR (0.7–5.5 MPa in the water content range of 0.11 to 0.22 m3 m−3) and λ (0.2–0.7 W m−1 K−1 from 0.05 to 0.22 m3 m−3), and increased k in the wet region but decreased k in the dry region. SRE treatment also reduced the overall soil water evaporation rate and cumulative water loss. Analysis of X‐ray computed tomography (CT) scanning showed that the SRE‐treated samples had a greater proportion of small pores (<60 μm). These changes were attributed mainly to SRE‐stimulated microbial activities. Highlights: The effects of incubating a sandy soil with a synthetic root exudate (SRE) on soil physical properties and evaporation are examined.SRE incubation increased the fraction of small pores.SRE incubation increased soil penetrometer resistance and thermal conductivity.Soil hydraulic conductivity was increased in the wet region but was reduced in the dry region.SRE incubation reduced the overall evaporation rate and cumulative water loss. [ABSTRACT FROM AUTHOR]

Summary: Iron is virtually an essential nutrient for all organisms, to understand how iron contributes to virulence of plant pathogenic fungi, we identified ClFTR1 and ClNPS6 in maize pathogen Curvularia lunata (Cochliobolus lunatus) in this study. Disruption of ClNPS6 significantly impaired siderophore biosynthesis. ClFTR1 and ClNPS6 did mediate oxidative stress but had no significant impact on vegetative growth, conidiation, cell wall integrity and sexual reproduction. Conidial germination delayed and appressoria formation reduced in ΔClftr1 comparing with wild type (WT) CX‐3. Genes responsible for conidial germination, appressoria formation, non‐host selective toxin biosynthesis and cell wall degrading enzymes were also downregulated in the transcriptome of ΔClftr1 and ΔClnps6 compared with WT. The conidial development, toxin biosynthesis and polygalacturonase activity were impaired in the mutant strains with ClFTR1 and ClNPS6 deletion during their infection to maize. ClFTR1 and ClNPS6 were upregulated expression at 12–24 and 48–120 hpi in WT respectively. ClFTR1 positively regulated conidial germination, appressoria formation in the biotrophy‐specific phase. ClNPS6 positively regulates non‐host selective toxin biosynthesis and cell wall degrading enzyme activity in the necrotrophy‐specific phase. Our results indicated that ClFTR1 and ClNPS6 were key genes of pathogen known to conidia development and virulence factors. [ABSTRACT FROM AUTHOR]

Glioblastoma (GBM) is the most common and malignant primary brain tumor in adults that originates from glial cells. The prognosis of patients with high-grade glioma is poor. It is therefore crucial to develop effective therapeutic strategies. Long non-coding RNAs (lncRNAs) have been reported as potential inducers or suppressors of tumor progression. Previous studies have indicated that the lncRNA Feline Leukemia Virus Subgroup C Cellular Receptor 1 Antisense RNA 1 (FLVCR1-AS1) is involved in the development and progression of gastric and lung cancer, as well as hepatocellular carcinoma and cholangiocarcinoma; however, the biological effect of FLVCR1-AS1 in glioma is not completely understood. The aim of the present study was to investigate how FLVCR1-AS1 modulates cell proliferation and invasion in glioma. FLVCR1-AS1 expression was significantly upregulated in GBM tissues compared with adjacent normal brain samples, and was higher in GBM cell lines compared with normal human astrocyte cells. Furthermore, the microRNA (miR)-30b-3p was revealed to be a putative target of FLVCR1-AS1, and the suppressive effects of miR-30b-3p on cellular proliferation and invasion were reversed following FLVCR1-AS1-knockdown. The results from Cell Counting Kit-8 and Transwell assays confirmed that FLVCR1-AS1-knockdown inhibited GBM cell proliferation and invasion ability. In addition, FLVCR1-AS1 was found to directly interact with miR-30b-3p, and a rescue experiment further established that FLVCR1-AS1 contributed to glioma progression by inhibiting miR-30b-3p. The results from the present study demonstrated that FLVCR1-AS1 may serve an oncogenic role in GBM and promote disease progression by interacting with miR-30b-3p. These findings suggested that FLVCR1-AS1 may be considered as a novel therapeutic target and diagnostic biomarker for GBM. [ABSTRACT FROM AUTHOR]

Background/Aims: Alcohol consumption has been shown to cause neuroinflammation and increase a variety of immune-related signaling processes. Microglia are a crucial part of alcohol-induced neuroinflammation and undergo apoptosis. Even though the importance of these inflammatory processes in the effects of alcohol-related neurodegeneration have been established, the mechanism of alcohol-induced microglia apoptosis is unknown. In prior research, we discovered that alcohol increases expression of salt-inducible kinase 1 (SIK1) in rodent brain tissue. In this study, we sought to determine what role SIK1 expression plays in alcohol-induced neuroinflammation as well as whether and by what mechanism it regulates microglia apoptosis. Methods: Adult C57BL/6 mice were divided into four groups and for 3 weeks treated with either 0%, 5%, 10%, or 15% alcohol during 3 hour periods. The mice were sacrificed and their brains excised for analysis. Additionally, primary microglia were isolated from neonatal mice. SIK1 expression in alcohol-treated brain tissue and microglia was analyzed via RT-PCR and western blotting. TUNEL staining, caspase-3, and caspase-9 activity assays were performed to evaluate microglial apoptosis. Cell fluorescence staining and NF-κB luciferase activity assays were used to evaluate the effects of SIK1 expression on the NF-κB signaling pathway. Results:SIK1 expression was increased in the brains of mice that consumed alcohol, and this effect was seen in mouse primary microglia. SIK1 knockdown in microglia increased alcohol-induced apoptosis in these cells. Furthermore, SIK1 reduced NF-κB signaling pathway factors, and SIK1 knockdown in microglia promoted alcohol-induced NF-κB activity. TUNEL staining, caspase-3, and caspase-9 activity assays consistently revealed that alcohol-induced microglial apoptosis was inhibited by depletion of p65. Finally, we determined that NF-κB signaling is required for alcohol-induced, SIK1-mediated apoptosis in microglia. Conclusion: This study establishes for the first time not only that SIK1 is crucial to regulating alcohol-induced microglial apoptosis, but also that the NF-κB signaling pathway is required for its activity. Overall, our results help elucidate mechanisms of alcohol-induced neuroinflammation. [ABSTRACT FROM AUTHOR]

It was reported that γ-irradiation had a controversial therapeutic effect on glioma cells. We aimed to investigate the cytotoxic effect on the glioma cells induced by γ-irradiation and explore the treatment to rescue the phenotype alteration of remaining cells. We used transwell assay to detect the glioma cell invasion and migration capacity. Cell proliferation and apoptosis were tested by the CCK-8 assay and flow cytometry respectively. Western Blot was used to detect the activity of Hedgehog signaling pathway and Epithelial-to-Mesenchymal Transition (EMT) status. γ-irradiation showed cytotoxic effect on LN229 cellsin vitro, whereas this contribution was limited in U251 cells. However, it could significantly stimulated EMT process in both LN229 and U251. Curcumin (CCM) could rescue EMT process induced by γ-irradiation via the suppression of Gli1 and the upregulation of Sufu. The location and expression of EMT markers were also verified by Immunofluorescence. Immunohistochemistry assay was used on intracranial glioma tissues of nude mice. The capacities of cell migration and invasion were suppressed with combined therapy. This research showed Curcumin could rescue the EMT process induced by γ-irradiation via inhibiting the Hedgehog signaling pathway and potentiate the cell cytotoxic effectin vivoandin vitro. [ABSTRACT FROM PUBLISHER]

Background: In recent years, miRNAs have been suggested to play key roles in the formation and development of human glioma. The aim of this study is to investigate the effect and mechanism of miR-184 expression on the malignant behavior of human glioma cells. Methods: The relative quantity of miR-184 was determined in human glioma cell lines, and the expression of hypoxia-inducible factor-1 alpha (HIF-1α) was explored using western blotting. The effects of miR-184 inhibition on cell viability and apoptosis were explored, and the miR-184 target gene was determined using a luciferase assay and western blotting. Flow cytometry and Hoechst staining were used to evaluate cell growth and apoptosis. Matrigel invasion and scratch assays were performed to measure the ability of cell invasion and migration. Results: miR-184 and HIF-1α protein levels were significantly upregulated in human glioma cells. Downregulation of miR-184 inhibited cell viability and increased the HEB cell apoptotic rate. Luciferase and western blot assays verified that FIH-1 was the target gene of miR-184 and negatively controlled the protein level of HIF-1α. Inhibition of HIF-1α by siRNA facilitated the apoptosis of HEB cells and suppressed A172 cell invasion and migration. Conclusion: miR-184 upregulation enhanced the malignant phenotype of human glioma cancer cells by reducing FIH-1 protein expression. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Soil compaction has become a global concern that reduces soil quality and may jeopardize agricultural sustainability. The objective of this study is to evaluate if the freezing–thawing process can alleviate the negative effects of soil compaction during overwinter time in Northeast China. The field experiment was a split plot design including two surface treatments (bare and mulch) and three compaction levels (low, moderate, and high compactions with initial bulk densities of 1.2, 1.4 and 1.6 g cm−3). Results showed that compared with initial values in the fall, freezing–thawing events increased soil porosity (by 4.28% to 25.68%) and the ratio of large-size pores (by 44.5% to 387.6%) after thawing in the spring. The greatest changes were observed in the high compaction treatment, and mulch-enhanced soil structural transformation. Additionally, the ratio of large-size aggregates (>1 mm) was increased and the fraction of small-size aggregates (<1 mm) was decreased. These changes in soil structural characteristics were attributed mainly to the modification of ice-filled pores space during the overwinter period. We concluded that the freezing–thawing process was an effective natural force for ameliorating soil compaction in Northeast China. [ABSTRACT FROM AUTHOR]