59 research outputs found
A plant cell wall-associated kinase encoding gene is dramatically downregulated during nematode infection of potato
Plant cell wall associated kinases (WAKs) and WAK-like kinases (WAKLs) have been increasingly recognized as important regulators of plant immunity against various plant pathogens. However, the role of the WAK/WAKL family in plant-nematode interactions remains to be determined. Here, we analyzed a WAK-encoding gene (Soltu.DM.02G029720.1) from potato (Solanum tuberosum). The Soltu.DM.02G029720.1 encoded protein contains domains characteristic of WAK/WAKL proteins and shows the highest similarity to SlWAKL2 from tomato (S. lycopersicum). We thus named the gene as StWAKL2. Phylogenetic analysis of a wide range of plant WAKs/WAKLs further revealed close similarity of StWAKL2 to three WAK/WAKL proteins demonstrated to play a role in disease resistance. To gain insights into the potential regulation and function of StWAKL2, transgenic potato lines containing the StWAKL2 promoter fused to the β-glucuronidase (GUS) reporter gene were generated and used to investigate StWAKL2 expression during plant development and upon nematode infection. Histochemical analyses revealed that StWAKL2 has specific expression patterns in potato leaf and root tissues. During nematode infection, GUS activity was mostly undetected at nematode infection sites over the course of nematode parasitism, although strong GUS activity was observed in root tissues adjacent to the infection region. Furthermore, mining of the transcriptomic data derived from cyst nematode infection of Arabidopsis roots identified a few WAK/WAKL genes, including a StWAKL2 homologue, found to be significantly down-regulated in nematode-induced feeding sites. These results indicated that specific suppression of WAK/WAKL genes in nematode-induced feeding sites might be crucial for cyst nematodes to achieve successful infection of host plants. Further studies are needed to uncover the role of WAK/WAKL genes in plant defenses against nematode infection.</p
Anion Recognition Triggered Nanoribbon-Like Self-Assembly: A Fluorescent Chemosensor for Nitrate in Acidic Aqueous Solution and Living Cells
A water-soluble
π-conjugated bispyridinium phenylenevinylene-based
fluorogenic probe has been developed as a novel fluorescent chemosensor
for highly selective, sensitive, and rapid detection of NO<sub>3</sub><sup>–</sup> anion in acidic aqueous media. This system self-assembles
to a nanoribbon as a result of ionic interaction. The positively charged
chemosensor generates a nearly instantaneous significant fluorescence
signal (475 vs 605 nm) in response to NO<sub>3</sub><sup>–</sup> in the green/yellow spectral region, with a large Stokes shift (130
nm). The fluorescence changes can be attributed to the self-aggregation
of the sensor triggered by ionic interaction, which occurs as a consequence
of the subtle cooperation of electrostatic ionic bonding, van der
Waals forces, and π-stacking of the π-conjugated aromatic
moieties. Importantly, this chemosensor has been employed for the
first time for the fluorescence detection of intracellular NO<sub>3</sub><sup>–</sup> anion in cultured cells
White Light Emission from Cucurbituril-Based Host–Guest Interaction in the Solid State: New Function of the Macrocyclic Host
Energy transfer and
interchange are central for fabricating white light-emitting organic
materials. However, increasing the efficiency of light energy transfer
remains a considerable challenge because of the occurrence of “cross
talk”. In this work, by exploiting the unique photophysical
properties of cucurbituril-triggered host–guest interactions,
the two complementary luminescent colors blue and yellow for white
light emission were independently obtained from a single fluorophore
dye rather than energy transfer. Further study suggested that the
rigid cavity of cucurbiturils efficiently prevented the aggregation
of the dye and improved its thermal stability in the solid state by
providing a regular nanosized fence for each encapsulated dye molecule.
As a result, a novel macrocycle-assisted supramolecular approach for
obtaining solid, white light-emitting organic materials with low cost,
high efficiency, and easy scale-up was successfully demonstrated
White Light Emission from Cucurbituril-Based Host–Guest Interaction in the Solid State: New Function of the Macrocyclic Host
Energy transfer and
interchange are central for fabricating white light-emitting organic
materials. However, increasing the efficiency of light energy transfer
remains a considerable challenge because of the occurrence of “cross
talk”. In this work, by exploiting the unique photophysical
properties of cucurbituril-triggered host–guest interactions,
the two complementary luminescent colors blue and yellow for white
light emission were independently obtained from a single fluorophore
dye rather than energy transfer. Further study suggested that the
rigid cavity of cucurbiturils efficiently prevented the aggregation
of the dye and improved its thermal stability in the solid state by
providing a regular nanosized fence for each encapsulated dye molecule.
As a result, a novel macrocycle-assisted supramolecular approach for
obtaining solid, white light-emitting organic materials with low cost,
high efficiency, and easy scale-up was successfully demonstrated
Effects of Risperidone and Prenatal Poly I:C Exposure on GABAA Receptors and AKT-GSK3β Pathway in the Ventral Tegmental Area of Female Juvenile Rats
The ventral tegmental area (VTA) in the ventral midbrain is the origin of the dopaminergic neurotransmission pathways. Although GABAA receptors and AKT-GSK3β signaling are involved in the pathophysiology of mental disorders and are modulated by antipsychotics, an unmet task is to reveal the pathological changes in these biomarkers and antipsychotic modulations in the VTA. Using a juvenile polyriboinosinic-polyribocytidylic acid (Poly I:C) psychiatric rat model, this study investigated the effects of adolescent risperidone treatment on GABAA receptors and AKT/GSK3β in the VTA. Pregnant female Sprague–Dawley rats were administered Poly I:C (5mg/kg; i.p) or saline at gestational day 15. Juvenile female offspring received risperidone (0.9 mg/kg, twice per day) or a vehicle from postnatal day 35 for 25 days. Poly I:C offspring had significantly decreased mRNA expression of GABAA receptor β3 subunits and glutamic acid decarboxylase (GAD2) in the VTA, while risperidone partially reversed the decreased GAD2 expression. Prenatal Poly I:C exposure led to increased expression of AKT2 and GSK3β. Risperidone decreased GABAA receptor β2/3, but increased AKT2 mRNA expression in the VTA of healthy rats. This study suggests that Poly I:C-elicited maternal immune activation and risperidone differentially modulate GABAergic neurotransmission and AKT-GSK3β signaling in the VTA of adolescent rats
Facile Cucurbit[8]uril-Based Supramolecular Approach To Fabricate Tunable Luminescent Materials in Aqueous Solution
Light-emitting materials with tunable
properties may offer fascinating
applications in optoelectronic devices, fluorescent sensors, and imaging
agents. Herein, a new supramolecular approach based on host–guest
interactions that greatly decreases the number of required synthetic
steps and produces a system with tunable and dynamical photophysical
properties was developed. Because of the novel electronic distributions
of the chromophore guest within the rigid hydrophobic cavity of the
cucurbit[8]uril host in this system, color tuning of emissions such
as cyan, yellow, green, and white light with efficiency increased
fluorescence lifetime, and quantum yield was easily achieved by simple
addition of the host in aqueous solution. Stimulus-responsive tuning
of color has long been an important area of research into light emissions.
The current study distinguishes itself by its combination of simple
steps using a single synthetic receptor and a single organic fluorophore
guest in a single solution. Our results may provide a promising advancement
of the fabrication of smart and tunable luminescent materials
Epigenetic histone acetylation modulating prenatal Poly I:C induced neuroinflammation in the prefrontal cortex of rats: a study in a maternal immune activation model
Introduction: Neuroinflammation in the central nervous system, particularly the prefrontal cortex (PFC), plays a role in the pathogenesis of schizophrenia, which has been found to be associated with maternal immune activation (MIA). Recent evidence suggests that epigenetic regulation involves in the MIA-induced neurodevelopmental disturbance. However, it is not well-understood how epigenetic modulation is involved in the neuroinflammation and pathogenesis of schizophrenia. Methods: This study explored the modulation of histone acetylation in both neuroinflammation and neurotransmission using an MIA rat model induced by prenatal polyriboinosinic-polyribocytidylic acid (Poly I:C) exposure, specifically examining those genes that were previously observed to be impacted by the exposure, including a subunit of nuclear factor kappa-B (Rela), Nod-Like-Receptor family Pyrin domain containing 3 (Nlrp3), NMDA receptor subunit 2A (Grin2a), 5-HT2A (Htr2a), and GABAA subunit β3 (Gabrb3). Results: Our results revealed global changes of histone acetylation on H3 (H3ace) and H4 (H4ace) in the PFC of offspring rats with prenatal Poly I:C exposure. In addition, it revealed enhancement of both H3ace and H4ace binding on the promoter region of Rela, as well as positive correlations between Rela and genes encoding histone acetyltransferases (HATs) including CREB-binding protein (CBP) and E1A-associated protein p300 (EP300). Although there was no change in H3ace or H4ace enrichment on the promoter region of Nlrp3, a significant enhancement of histone deacetylase 6 (HDAC6) binding on the promoter region of Nlrp3 and a positive correlation between Nlrp3 and Hdac6 were also observed. However, prenatal Poly I:C treatment did not lead to any specific changes of H3ace and H4ace on the promoter region of the target genes encoding neurotransmitter receptors in this study. Discussion: These findings demonstrated that epigenetic modulation contributes to NF-κB/NLRP3 mediated neuroinflammation induced by prenatal Poly I:C exposure via enhancement of histone acetylation of H3ace and H4ace on Rela and HDAC6-mediated NLRP3 transcriptional activation. This may further lead to deficits in neurotransmissions and schizophrenia-like behaviors observed in offspring
Macrofibers with High Mechanical Performance Based on Aligned Bacterial Cellulose Nanofibers
Bacterial
cellulose (BC) nanofibers represent an emerging class of highly crystalline
bionanofibers with high intrinsic mechanical properties. The remarkable
nanofibers with oriented structure and strong interfibrillar interactions
can realize high-performance materials. In this study, we demonstrated
that macrofibers based on aligned BC nanofibers could be prepared
by wet spinning and drawing procedures. The relationship between process
conditions, structure, and mechanical properties of macrofibers were
investigated. The obtained macrofibers exhibited Young’s modulus
of 16.4 GPa and tensile strength of 248.6 MPa under the optimum process
conditions, in which nanofibers displayed a high degree of alignment.
Furthermore, we enhanced the interfacial interactions between nanofibers
and obtained better mechanical performance by multivalent ion cross-linking.
After exchanging the monovalent Na+ by Fe3+,
the dried macrofiber reached Young’s modulus of 22.9 GPa and
tensile strength of 357.5 MPa. Particularly, the resulting macrofibers
still maintained good mechanical properties with Young’s modulus
of 15.9 GPa and tensile strength of 262.2 MPa in the wet condition.
This research provided a good method to fabricate macrofibers from
BC nanofibers with good properties by continuous wet-spinning process.
These macrofibers can be easily functionalized and have promising
potential applications in smart textiles, biosensor, and structural
reinforcement
Macrofibers with High Mechanical Performance Based on Aligned Bacterial Cellulose Nanofibers
Bacterial
cellulose (BC) nanofibers represent an emerging class of highly crystalline
bionanofibers with high intrinsic mechanical properties. The remarkable
nanofibers with oriented structure and strong interfibrillar interactions
can realize high-performance materials. In this study, we demonstrated
that macrofibers based on aligned BC nanofibers could be prepared
by wet spinning and drawing procedures. The relationship between process
conditions, structure, and mechanical properties of macrofibers were
investigated. The obtained macrofibers exhibited Young’s modulus
of 16.4 GPa and tensile strength of 248.6 MPa under the optimum process
conditions, in which nanofibers displayed a high degree of alignment.
Furthermore, we enhanced the interfacial interactions between nanofibers
and obtained better mechanical performance by multivalent ion cross-linking.
After exchanging the monovalent Na<sup>+</sup> by Fe<sup>3+</sup>,
the dried macrofiber reached Young’s modulus of 22.9 GPa and
tensile strength of 357.5 MPa. Particularly, the resulting macrofibers
still maintained good mechanical properties with Young’s modulus
of 15.9 GPa and tensile strength of 262.2 MPa in the wet condition.
This research provided a good method to fabricate macrofibers from
BC nanofibers with good properties by continuous wet-spinning process.
These macrofibers can be easily functionalized and have promising
potential applications in smart textiles, biosensor, and structural
reinforcement
Suzuki Coupling Reaction of 1,6,7,12-Tetrabromoperylene Bisimide
1,6,7,12-Tetrabromoperylene-3,4,9,10-tetracarboxylic acid bisanhydride and the corresponding tetrabrominated perylene bisimide were first
synthesized with high yields. The Suzuki coupling reaction of novel tetrabromoperylene bisimide with phenylbonoric acid was studied. The
four bromines in the bay position of the perylene core were substituted successfully to yield 1,6,7,12-teraphenylperylene bisimide. The
photochemical properties of the novel perylene bisimides were studied and presented
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