45 research outputs found
The BR signaling pathway regulates primary root development and drought stress response by suppressing the expression of PLT1 and PLT2 in Arabidopsis thaliana
IntroductionWith the warming global climate, drought stress has become an important abiotic stress factor limiting plant growth and crop yield. As the most rapidly drought-sensing organs of plants, roots undergo a series of changes to enhance their ability to absorb water, but the molecular mechanism is unclear.Results and methodsIn this study, we found that PLT1 and PLT2, two important transcription factors of root development in Arabidopsis thaliana, are involved in the plant response to drought and are inhibited by BR signaling. PLT1- and PLT2-overexpressing plants showed greater drought tolerance than wild-type plants. Furthermore, we found that BZR1 could bind to the promoter of PLT1 and inhibit its transcriptional activity in vitro and in vivo. PLT1 and PLT2 were regulated by BR signaling in root development and PLT2 could partially rescue the drought sensitivity of bes1-D. In addition, RNA-seq data analysis showed that BR-regulated root genes and PLT1/2 target genes were also regulated by drought; for example, CIPK3, RCI2A, PCaP1, PIP1;5, ERF61 were downregulated by drought and PLT1/2 but upregulated by BR treatment; AAP4, WRKY60, and AT5G19970 were downregulated by PLT1/2 but upregulated by drought and BR treatment; and RGL2 was upregulated by drought and PLT1/2 but downregulated by BR treatment.DiscussionOur findings not only reveal the mechanism by which BR signaling coordinates root growth and drought tolerance by suppressing the expression of PLT1 and PLT2 but also elucidates the relationship between drought and root development. The current study thus provides an important theoretical basis for the improvement of crop yield under drought conditions
The Synthesis and Initial Evaluation of MerTK Targeted PET Agents
MerTK (Mer tyrosine kinase), a receptor tyrosine kinase, is ectopically or aberrantly expressed in numerous human hematologic and solid malignancies. Although a variety of MerTK targeting therapies are being developed to enhance outcomes for patients with various cancers, the sensitivity of tumors to MerTK suppression may not be uniform due to the heterogeneity of solid tumors and different tumor stages. In this report, we develop a series of radiolabeled agents as potential MerTK PET (positron emission tomography) agents. In our initial in vivo evaluation, [18F]-MerTK-6 showed prominent uptake rate (4.79 ± 0.24%ID/g) in B16F10 tumor-bearing mice. The tumor to muscle ratio reached 1.86 and 3.09 at 0.5 and 2 h post-injection, respectively. In summary, [18F]-MerTK-6 is a promising PET agent for MerTK imaging and is worth further evaluation in future studies
RecET recombination system driving chromosomal target gene replacement in Zymomonas mobilis
Background: Zymomonas mobilis is a Gram-negative microaerophilic bacterium with excellent ethanol-producing capabilities. The RecET recombination system provides an efficient tool for direct targeting of genes in the bacterial chromosome by PCR fragments. Results: The plasmids pSUZM2a-RecET and pSUZM2a-RecE588T were first developed to co-express RecE or RecE588 and RecT for homologous recombination. Thereafter, the PCR fragments of the tetracycline resistance marker gene flanked by 60 bp of adhA (alcohol dehydrogenase I) or adhB (alcohol dehydrogenase II) homologous sequences were electroporated directly into ZM4 cells harboring pSUZM2a-RecET or pSUZM2a-RecE588T. Both adhA and adhB were replaced by the tetracycline resistance gene in ZM4, yielding two mutant strains, Z. mobilis ZM4 ΔadhA and Z. mobilis ZM4 ΔadhB. These two mutants showed varying extent of reduction in ethanol production, biomass generation, and glucose metabolism. Furthermore, enzyme activity of alcohol dehydrogenase II in Z. mobilis ZM4 ΔadhB exhibited a significant reduction compared to that of wild-type ZM4. Conclusion: This approach provided a simple and useful method for introducing mutations and heterologous genes in the Z. mobilis genome. Keywords: Dehydrogenase gene, Electroporation, Ethanol, Genetic manipulation, Gram negative, Industrial applications, Knock-out, Primer, Production, Recombination, Vecto
The Synthesis and Initial Evaluation of MerTK Targeted PET Agents
MerTK (Mer tyrosine kinase), a receptor tyrosine kinase, is ectopically or aberrantly expressed in numerous human hematologic and solid malignancies. Although a variety of MerTK targeting therapies are being developed to enhance outcomes for patients with various cancers, the sensitivity of tumors to MerTK suppression may not be uniform due to the heterogeneity of solid tumors and different tumor stages. In this report, we develop a series of radiolabeled agents as potential MerTK PET (positron emission tomography) agents. In our initial in vivo evaluation, [18F]-MerTK-6 showed prominent uptake rate (4.79 ± 0.24%ID/g) in B16F10 tumor-bearing mice. The tumor to muscle ratio reached 1.86 and 3.09 at 0.5 and 2 h post-injection, respectively. In summary, [18F]-MerTK-6 is a promising PET agent for MerTK imaging and is worth further evaluation in future studies
Anisotropic Cracking of Nanocrystal Superlattices
The
synthesis colloidal nanocrystals in nonpolar organic solvents
has led to exceptional size- and shape-control, enabling the formation
of nanocrystal superlattices isostructural to atomic lattices built
with nanocrystals rather than atoms. The long aliphatic ligands (e.g.,
oleic acid) used to achieve this control separate nanocrystals too
far in the solid state for most charge-transporting devices. Solid-state
ligand exchange, which brings particles closer together and enhances
conductivity, necessitates large changes in the total volume of the
solid (compressive stress), which leads to film cracking. In this
work, truncate octahedral lead selenide nanocrystals are shown to
self-assemble into body-centered cubic superlattices in which the
atomic axes of the individual nanocrystals are coaligned with the
crystal axes of the superlattice. Due to this coalignment, upon ligand
exchange of the superlattices, cracking is preferentially observed
on ⟨011⟩ superlattice directions. This observation is
related to differences in the ligand binding to exposed {100} and
{111} planes of the PbSe nanocrystal surfaces. This result has implications
for binary and more complex structures in which differential reactivity
of the constituent elements can lead to disruption of the desired
structure. In addition, cracks in PbSe superlattices occur in a semiregular
spacings inversely related to the superlattice domain size and strongly
influenced by the presence of twin boundaries, which serve as both
emission centers and propagation barriers for fractures. This work
shows that defects, similar to behavior in nanotwinned metals, could
be used to engineer enhanced mechanical strength and electrical conductivity
in nanocrystal superlattices
Enantioselective Fluorescent Recognition in the Fluorous Phase: Enhanced Reactivity and Expanded Chiral Recognition
A novel
perfluoroalkyl-BINOL-based chiral diketone is found to
be the first highly enantioselective fluorescent sensor in the fluorous
phase. One enantiomer of a chiral amino alcohol or diamine at a concentration
greater than 1 mM can cause an up to 1200–2000-fold fluorescent
enhancement of the sensor (0.08 mM), while the other enantiomer gives
only a 10–50-fold enhancement. The fluorous-phase-based sensor
is found to enhance the reactivity of the previously reported fluorous
insoluble sensor with amino alcohols and expand its chiral recognition
ability. Dynamic light scattering studies show the formation of aggregates
of very different particle sizes when two enantiomers of a substrate
interact with the sensor in perfluorohexane (FC-12). This substantial
difference enables easy discrimination of the enantiomers with UV-lamps
or even the naked eye. NMR, IR, and mass spectroscopic studies indicate
that the fluorescent enhancement and enantioselectivity should originate
from the fluorous solvent-promoted nucleophilic addition of the amino
alcohols to the carbonyl groups of the sensor
Overexpression of long non-coding RNA SOX2OT promotes esophageal squamous cell carcinoma growth
Abstract Background SOX2 overlapping transcript (SOX2OT) has been reported to be an important lncRNA in various cancers. SOX2 is embedded in an intron of the SOX2OT gene. But the role of SOX2OT in esophageal squamous cell carcinoma (ESCC) and the association between SOX2OT and SOX2 remain unclear. Methods Quantitative PCR (qPCR) was used to detect the expression of SOX2OT and SOX2 in ESCC tissues and cells. The isoforms of SOX2OT were identified by PCR and confirmed by sequencing. CCK-8 and Edu assays were performed to investigate the effects of SOX2OT on cell growth. The relationship between SOX2OT and SOX2 was explored by luciferase reporter assay. Results Both SOX2OT and SOX2 were upregulated in ESCC tissues and cells. SOX2OT expression was positively associated with SOX2 expression in ESCC tissues. NR_004053 was one of the major SOX2OT transcripts aberrantly expressed in ESCC tissues and cells. Overexpression of SOX2OT (NR_004053) promoted ESCC cell growth, antagonized the effect of DDP and increased cell proliferation ratio. Ectopic expression of SOX2 could increase the luciferase activity of SOX2OT-pGL3/Basic and SOX2OT expression, while overexpression of SOX2OT (NR_004053) had no effect on SOX2 expression. Conclusion Our study demonstrates that the major isoform of SOX2OT in ESCC, SOX2OT (NR_004053) contributes to cell growth. SOX2 promotes SOX2OT expression at transcriptional level
Synthesis and Characterization of Reduced Graphene Oxide-Supported Nanoscale Zero-Valent Iron (nZVI/rGO) Composites Used for Pb(II) Removal
Reduced graphene oxide-supported nanoscale zero-valent iron (nZVI/rGO) composites were prepared by chemical deposition method and were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, N2-sorption and X-ray photoelectron spectroscopy (XPS). Operating parameters for the removal process of Pb(II) ions, such as temperature (20–40 °C), pH (3–5), initial concentration (400–600 mg/L) and contact time (20–60 min), were optimized using a quadratic model. The coefficient of determination (R2 > 0.99) obtained for the mathematical model indicates a high correlation between the experimental and predicted values. The optimal temperature, pH, initial concentration and contact time for Pb(II) ions removal in the present experiment were 21.30 °C, 5.00, 400.00 mg/L and 60.00 min, respectively. In addition, the Pb(II) removal by nZVI/rGO composites was quantitatively evaluated by using adsorption isotherms, such as Langmuir and Freundlich isotherm models, of which Langmuir isotherm gave a better correlation, and the calculated maximum adsorption capacity was 910 mg/g. The removal process of Pb(II) ions could be completed within 50 min, which was well described by the pseudo-second order kinetic model. Therefore, the nZVI/rGO composites are suitable as efficient materials for the advanced treatment of Pb(II)-containing wastewater
Expression levels of key immune indicators and immune checkpoints in manganese-exposed rats
Manganese is essential trace elements, to participate in the body a variety of biochemical reactions, has important physiological functions, such as stimulate the immune cell proliferation, strengthen the cellular immunity, etc. However, excessive manganese exposure can cause damage to multiple systems of the body.The immune system is extremely vulnerable to external toxicants, however manganese research on the immune system are inadequate and biomarkers are lacking. Therefore, here we applied a manganese-exposed rat model to make preliminary observations on the immunotoxic effects of manganese. We found that manganese exposure inhibited humoral immune function in rats by decreasing peripheral blood IgG (ImmunoglobulinG, IgG), IgM (ImmunoglobulinM, IgM) and complement C3 levels; It also regulates rat cellular immune activity by influencing peripheral blood, spleen, and thymus T cell numbers and immune organ ICs (Immune Checkpoints, ICs) and cytokine expression. Furthermore, it was revealed that the impact of manganese exposure on the immune function of rats exhibited a correlation with both the dosage and duration of exposure. Notably, prolonged exposure to high doses of manganese had the most pronounced influence on rat immune function, primarily manifesting as immunosuppression.The above findings suggest that manganese exposure leads to impaired immune function and related changes in immune indicators, or may provide clues for the discovery of its biomarkers