Glucose functions as a hormone‐like signalling molecule that modulates plant growth and development in Arabidopsis thaliana. However, the role of glucose in root elongation remains elusive. Our study ...demonstrates that high concentrations of glucose reduce the size of the root meristem zone by repressing PIN1 accumulation and thereby reducing auxin levels. In addition, we verified the involvement of ABA INSENSITIVE 5 (ABI5) in this process by showing that abi5‐1 is less sensitive to glucose than the wild type, whereas glucose induces ABI5 expression and the inducible overexpression of ABI5 reduces the size of the root meristem zone. Furthermore, the inducible overexpression of ABI5 in PIN1::PIN1‐GFP plants reduces the level of PIN1‐GFP, but glucose reduces the level of PIN1‐GFP to a lesser extent in abi5‐1 PIN1::PIN1‐GFP plants than in the PIN1::PIN1‐GFP control, suggesting that ABI5 is involved in glucose‐regulated PIN1 accumulation. Taken together, our data suggest that ABI5 functions in the glucose‐mediated inhibition of the root meristem zone by repressing PIN1 accumulation, thus leading to reduced auxin levels in roots.
Seed germination is a complex process that is regulated by various exogenous and endogenous factors, in which abscisic acid (ABA) plays a crucial role. The triphosphate tunnel metalloenzyme (TTM) ...superfamily exists in all living organisms, but research on its biological role is limited. Here, we reveal that
functions in ABA-mediated seed germination. Our study indicates that
expression is enhanced but repressed by ABA during seed germination. Promoted
expression in
rescues ABA-mediated inhibition of seed germination and early seedling development and
mutants exhibit lower seed germination rate and reduced cotyledon greening compared with the wild type, revealing that the repression of
expression is required for ABA-mediated inhibition of seed germination and early seedling development. Further, ABA inhibits
expression by ABA insensitive 4 (ABI4) binding of
promoter and the ABA-insensitive phenotype of
with higher
expression can be rescued by mutation of
in
mutant, indicating that
acts downstream of
. In addition,
, a homolog of
, is not involved in ABA-mediated regulation of seed germination. In summary, our findings reveal that TTM2 acts as a downstream factor of ABI4 in ABA-mediated seed germination and early seedling growth.
Herein, one interdigitated molecular and two metallarectangles were realized successfully using two rigid bidentate ligands (L1, L2) and two building blocks (E1, E2) via coordination-driven ...self-assembly strategy. Interestingly, a novel interdigitated structure has been successfully formed through triple π-π stacking interactions, different from the previously reported interlocked 2catenanes. Based on the π-π stacking interaction, nonradiative transitions were promoted and obvious photothermal transitions effect was triggered in solution and solid states. In addition, it is found that the interdigitated structure has a decent photothermal conversion efficiency of about 12% in solution state. This study provides open up new ideas for our future development of near-infrared photothermal conversion materials.
A series of discrete metallarectangles and an interdigitated molecule were synthesized by coordination-driven self-assembly. These topologies were unambiguously confirmed by NMR spectroscopy, ESI-MS, IR spectroscopy as well as X-ray crystallography. In addition, triple π-π stacking interactions were found in the interdigitated structure, which results in the capability of photothermal conversion. Display omitted
•One interdigitated molecular and two metallarectangles were realized successfully using two rigid bidentate ligands and two building blocks via coordination-driven self-assembly strategy.•The interdigitated structure was constructed through triple π-π stacking interactions, different from the previously reported interlocked 2catenanes, which result in nonradiative transitions and trigger photothermal conversion in both the solution and the solid states.•The photothermal conversion study exhibits a good photothermal conversion efficiency (12%) for the interdigitated structure at 660 nm in the solution state. This study provides open up new ideas for our future development of near-infrared photothermal conversion materials.
Herein, a new Zn-MOF material, Zn(
)(
),
, was built successfully through a one-pot solvothermal method. The 3D MOF structure was determined by Single X-ray diffraction analysis, IR, and elemental ...analysis. A series of PXRD tests of
after being immersed in different solvents and pH solutions demonstrated the good stability of
. Interestingly, this material displayed high catalytic activity for the visible-light-driven hydrogen generation under the illumination of white LED in pure water or a mixture of DMF and H
O without additional photosensitizers and cocatalysts. Besides, the studies also showed that the catalytic activity changed constantly as well as the solvent ratio adjustment of DMF and H
O from 4:6 to 2:8. Additionally, the catalytic activity reached the best value (743 μmol g
h
) when the solvent ratio was 4:6. The heterogeneous nature and recyclability of the MOF catalyst, as well as several factors that affect the catalytic activity, were investigated and described in detail. Moreover, the photocatalytic mechanism for the hydrogen generation of
was also proposed based on the fluorescence spectra and UV-vis absorption.
Neonatal hypoxic–ischaemic (HI) injury is a serious complication of neonatal asphyxia and the leading cause of neonatal acute death and chronic neurological injury, and the effective therapeutic ...method is lacking to improve patients' outcomes. We reported in this study that panax notoginseng saponin (PNS) may provide a treatment option for HI. HI model was established using neonatal Sprague–Dawley rats and then intraperitoneally injected with different dosage of PNS, once a day for 7 days. Histological staining and behavioural evaluations were performed to elucidate the pathological changes and neurobehavioural variation after PNS treatment. We found PNS administration significantly reduced the infarct volume of brain tissues and improved the autonomous activities of neonatal rats, especially with higher dosage. PNS treatment at 40 mg/kg reduced neuronal damage, suppressed neuronal apoptosis and depressed astroglial reactive response. Moreover, the long‐term cognitive and motor functions were also improved after PNS treatment at 40 mg/kg. Importantly, PNS treatment elevated the levels of BDNF and TrkB but decreased the expression of p75NTR both in the cortex and hippocampus of HI rats. The therapeutic efficacy of PNS might be correlated with PNS‐activated BDNF/TrkB signalling and inactivation of p75NTR expression, providing a novel potential therapy for alleviating HI injury.
PNS ameliorated the acute cerebral injury induced by HI in neonatal rats. PNS treatment suppressed the neuronal apoptosis in neonatal HI rats and alleviated GFAP‐mediated inflammatory response. The long‐term neurological dysfunctions in neonatal HI rats were relieved after PNS treatment.
Although the selective synthesis of complicated supramolecular architectures has seen significant progress in recent years, the exploration of the properties of these complexes remains a fascinating ...challenge. Herein, a series of new supramolecular topologies, metalla2catenanes and Borromean ring assemblies, were constructed based on appropriate Cp*Rh building blocks and two rigid alkynyl pyridine ligands (
L1
,
L2
)
via
coordination-driven self-assembly. Interestingly, minor differences between the two rigid alkynyl pyridine ligands with/without organic substituents led to products with dramatically different topologies. Careful structural analysis showed that π-π stacking interactions play a crucial role in stabilizing these 2catenanes and Borromean ring assemblies, while also promoting nonradiative transitions and triggering photothermal conversion in both the solution and the solid states. These results were showcased through comparative studies of the NIR photothermal conversion efficiencies of the Borromean ring assemblies, 2catenanes and metallarectangles, which exhibited a wide range of photothermal conversion efficiencies (12.64-72.21%). The influence of the different Cp*Rh building blocks on the NIR photothermal conversion efficiencies of their assemblies was investigated. Good photothermal conversion properties of the assemblies were also found in the solid state. This study provides a new strategy to construct valuable half-sandwich-based NIR photothermal conversion materials while also providing promising candidates for the further development of materials science.
The selective synthesis of three kinds of supermolecular topologies, molecular Borromean ring, 2catenane and metallarectangle based on two alkynyl ligands is presented. Remarkably, the NIR photothermal conversion efficiency was found to improve as the π-π stacking increases.
A novel and efficient CP bond formation reaction of diarylphosphine oxides with aryl iodides was achieved by combining nickel catalysis and visible‐light‐induced photoredox catalysis. This ...dual‐catalytic reaction showed a broad substrate scope, excellent functional group tolerance, and afforded the corresponding products in good to excellent yields. Compared with the previously reported use of photoredox/nickel dual catalysis in the construction of CC bonds, the methodology described herein was observed to be the first to allow for C‐heteroatom bond formation.
Dual catalysis: A novel and efficient CP bond formation reaction of diarylphosphine oxides with aryl iodides was achieved by combining nickel catalysis and visible‐light‐induced photoredox catalysis (see scheme). This dual‐catalytic reaction showed a broad substrate scope, excellent functional‐group tolerance, and afforded the corresponding products in good to excellent yields. Compared with previously reported photoredox/nickel dual catalytic systems, this methodology is the first to allow for Cheteroatom bond formation.
Intricately interwoven topologies are continually being synthesized and are ultimately equally versatile and significant at the nanoscale level; however, reports concerning ravel structures, which ...are highly entwined new topological species, are extremely rare and fraught with tremendous synthesis challenges. To solve the synthesis problem, a tetrapodontic pyridine ligand L1 with two types of olefinic bond units and two Cp*M‐based building blocks (E1, M=Rh; E2, M=Ir) featuring large conjugated planes was prepared to perform the self‐assembly. Two unprecedented 5+10 icosanuclear molecular 4‐ravels containing four crossings were obtained by parallel‐displaced π⋅⋅⋅π interactions in a single‐step strategy. Remarkably, reversible structural transformations between the 4‐ravel and the corresponding metallocage could be realized by concentration changes and solvent‐ and guest‐induced effects. X‐ray crystallographic data and NMR spectroscopy provide full confirmation of these phenomena.
Two unprecedented 5+10 icosanuclear molecular 4‐ravels containing four crossings have been generated using a single‐step strategy. This topology is achieved by utilizing parallel‐displaced π⋅⋅⋅π interactions with carefully selected naphthoquinoyl Cp*M building blocks and X‐shaped pyridyl ligands.
A photocatalytic formal 3+2 cycloaddition of 2H‐azirines with alkynes has been achieved under irradiation by visible light in the presence of organic dye photocatalysts. This transformation provides ...efficient access to highly functionalized pyrroles in good yields and has been applied to the synthesis of drug analogues. A primary trial of photocascade catalysis merging energy transfer and redox neutral reactions was shown to be successful.
Photo(chemistry) op: A photocatalytic formal 3+2 cycloaddition of 2H‐azirines with alkynes has been established under the irradiation of visible light in the presence of an organic dye. This transformation provides efficient access to highly functionalized pyrroles in good yields and has been applied to the formal synthesis of an inhibitor for HMG‐CoA reductase.
The controlled synthesis of organometallic supramolecular macrocycles cages remains interesting and challenging work in the field of supramolecular chemistry. Here, two tetranuclear rectangular ...macrocycles and an octuclear cage were designed and synthesized utilizing a rigid and functionalized pillar linker, 2,6-bis(pyridin-4-yl)-1,7-dihydrobenzo 1,2-d:4,5-d′diimidazole (BBI4PY) based on three half-sandwich rhodium building blocks bearing different sizes. X-ray crystallography in combination with 1H NMR spectroscopy elucidated that the two building blocks with shorter spacers only result in rectangular macrocycles. However, the building block of bulkier size to avoid the π-π stacking interactions between two ligands BBI4PY led to the formation of an octuclear cage complex. The latter cage contains two types of metal ions, namely Rh3+ and Cu2+, showing significant characteristics of heterogeneous metal-assembling compounds. In addition, the cage accommodates two free isopropyl ether solvent molecules, thus displaying host–guest behavior.
