Physiological and Structural Changes in Leaves of Platycrater arguta Seedlings Exposed to Increasing Light Intensities.

Understanding the light adaptation of plants is critical for conservation. Platycrater arguta, an endangered deciduous shrub endemic to East Asia, possesses high ornamental and phylogeographic value. However, the weak environmental adaptability of P. arguta species has limited its general growth and conservation. To obtain a deeper understanding of the P. arguta growth conditions, we examined the leaf morphology and physiology via anatomical and chloroplast ultrastructural analyses following exposure to different natural light intensities (full light, 40%, and 10%). The findings indicated that P. arguta seedings in the 10% light intensity had significantly improved leaf morphological characteristics and specific leaf area compared to those exposed to other intensities. The net photosynthetic rate, chlorophyll (Chl) content, photosynthetic nitrogen use efficiency (PNUE), and photosynthetic phosphorus use efficiency (PPUE) exhibited marked increases at a 10% light intensity compared to both 40% light and full light intensities, whereas the light compensation point and dark respiration levels reached their lowest values under the 10% light condition. With reduced light, leaf thickness, palisade tissue, spongy tissue, and stomatal density significantly decreased, whereas the stomatal length, stomatal width, and stomatal aperture were significantly elevated. When exposed to 10% light intensity, the ultrastructure of chloroplasts was well developed, chloroplasts and starch grain size, the number of grana, and thylakoids all increased significantly, while the number of plastoglobules was significantly reduced. Relative distance phenotypic plasticity index analysis exhibited that P. arguta adapts to varying light environments predominantly by adjusting PPUE, Chl b, PNUE, chloroplast area, and the activity of PSII reaction centers. We proposed that P. arguta efficiently utilizes low light to reconfigure its energy metabolism by regulating its leaf structure, photosynthetic capacity, nutrient use efficiency, and chloroplast development.

Knockdown of BCL-3 Attenuates Inflammatory Response in Intracerebral Hemorrhage Through an rBMECs/MGs Microenvironment.

Intracerebral hemorrhage (ICH) is a severe disease with high mortality. Recently, the role of BCL-3 in ICH has started to gain attention, but its mechanism remains unclear. A collagenase injection method was used to establish an ICH model in rats, and the expression of BCL-3 were detected. Rat brain microvascular endothelial cells (rBMECs) were isolated and induced with Hemin to establish an in vitro ICH model. The expression of BCL-3 was assessed, followed by detection of cell apoptosis. In the cell model, the recruitment, polarization, and pro-inflammatory features of the microglia (MGs) were assessed after co-cultured with rBMECs. Finally, in the ICH animal model, after knockdown of BCL-3, comprehensive evaluations of inflammatory responses in brain tissue, polarization and recruitment of microglia, and apoptosis were conducted. Results revealed an upregulated expression of BCL-3 in brain tissue of the ICH animal model. In Hemin-treated rBMECs, an upward trend in BCL-3 expression was observed, accompanied by an increase of cell apoptosis. After co-culturing with the in vitro model, microglia exhibited enhanced M1 polarization and intensified inflammatory responses. However, when BCL-3 expression was inhibited in the in vitro model, a reversal occurred in the polarization tendency and inflammatory responses of microglia. Additionally, after knockdown of BCL-3 in the animal model, notable improvements occurred in M1 polarization, infiltration of macrophages, and inflammatory reactions in the brain tissue. Therefore, BCL-3 modulates the inflammatory response after ICH occurrence through the BMECs/MGs microenvironment. Additionally, BCL-3 might be a potential therapeutic target for ICH management.

Liriogerphines E-U, further unique sesquiterpene-alkaloid hybrids from the rare Chinese tulip tree.

Seventeen undescribed sesquiterpene-alkaloid hybrids (liriogerphines E-U, 1-17) were isolated and identified during a further phytochemical investigation on the branches and leaves of Chinese tulip tree (Liriodendron chinense), a rare medicinal and ornamental plant endemic to China. These unique heterodimers are conjugates of germacranolide-type sesquiterpenoids with structurally diverse alkaloids [i.e., aporphine- (1-15), proaporphine- (16), and benzyltetrahydroisoquinoline-type (17)] via the formation of a C-N bond. The previously undescribed structures were elucidated by comprehensive spectroscopic data analyses and electronic circular dichroism calculations. Such a class of sesquiterpene-alkaloid hybrids presumably biosynthesized via an aza-Michael addition is quite rare from terrestrial plants. In particular, the sesquiterpene-benzyltetrahydroisoquinoline hybrid skeleton has never been reported until the present study. All the isolates were evaluated for their cytotoxic effects against a small panel of leukemia cell lines (Raji, Jeko-1, Daudi, Jurkat, MV-4-11 and HL-60), and some of them exhibited considerable activities.

Near-Infrared, Organic Chiroptic Switch with High Dissymmetry Factors.

Here we unveil a chiral molecular redox switch derived from PDI-based twistacenes─chPDI[2] that has the remarkable attributes of high-intensity and a broadband chiral response. This material exhibits facile, stable, and reversible multistate chiroptical switching behavior over a broad active wavelength range close to 700 nm, encompassing ultraviolet, visible, and near-infrared regions. Upon reduction, chPDI[2] exhibits a substantial increase in the amplitude of its circular dichroic response, with an outstanding |ΔΔε| > 300 M-1 cm-1 and a high dissymmetry factor of 3 × 10-2 at 960 nm. DFT calculations suggest that the long wavelength CD signal for doubly reduced chPDI[2] originates from excitation of the PDI backbone to the π* orbital of the bridging alkene. Importantly, the dimer's molecular contortion facilitates ionic diffusion, enabling chiral switching in solid state films. The high dissymmetry factors and near-infrared response establish chPDI[2] as a unique chiroptic switch.

Functions of arbuscular mycorrhizal fungi in regulating endangered species Heptacodium miconioides growth and drought stress tolerance.

KEY MESSAGE: The important values of AMF in regulating endangered species Heptacodium miconioides growth and drought stress tolerance. The wild endangered tree Heptacodium miconioides is distributed sporadically in mountainous areas and often subjected to various abiotic stresses, such as drought. The mutualistic association between plants and arbuscular mycorrhizal fungi (AMF) is known to have a significant impact on plant growth and their ability to withstand drought conditions. However, the role of AMF in H. miconioides seedlings in regulating drought tolerance remains unknown. This study investigated the ability of AMF symbionts to mitigate drought and their underlying mechanism on H. miconioides leaves. The results showed that drought stress dramatically decreased the leaf biomass and damaged the chloroplast structure in seedlings. Conversely, inoculation with AMF noticeably alleviated the deleterious effects of drought stress by restoring leaf morphology and improving the photosynthetic capacity. Moreover, plants inoculated with AMF enhanced the proportion of palisade tissue to spongy tissue in the leaves and the size of starch grains and number of plastoglobules in the chloroplast ultrastructure. A transcriptomic analysis showed that 2157 genes (691 upregulated and 1466 downregulated) were differentially expressed between drought stress with AMF inoculation and drought treatment. Further examination demonstrated that the genes exhibiting differential expression were predominantly associated with the advancement of photosynthesis, sucrose and starch metabolism, nitrogen metabolism, chloroplast development, and phenylpropanoid biosynthetic pathways, and the key potential genes were screened. These findings conclusively provided the physiological and molecular mechanisms that underlie improved drought resistance in H. miconioides in the presence of AMF, which could contribute to improving the survival and species conservation of H. miconioides.

BCL-3 Promotes Intracerebral Hemorrhage Progression by Increasing Blood-Brain Barrier Permeability, Inflammation, and Cell Apoptosis via Endoplasmic Reticulum Stress.

Background: Intracerebral hemorrhage (ICH) is among the common types of stroke with high mortality and morbidity. Molecular biomarker selection is crucial for ICH diagnosis and treatment. However, the identification of ICH-related biomarkers remains inadequate. Materials and Methods: In vivo and in vitro ICH models were generated and transfected with silenced B-cell lymphoma-3 (BCL-3 and siRNA BCL-3), overexpressed BCL-3, and endoplasmic reticulum stress (ERS) agonist (2-CLHA). Hematoxylin-eosin staining and transmission electron microscopy were used to observe the transfected cells. RNA sequencing was performed in vivo on the sham and ICH groups. The blood-brain barrier (BBB) permeability was evaluated by determining Evans blue dye extravasation, transendothelial electrical resistance, and paracellular permeability. Moreover, tight junction-, cell apoptosis-, and endoplasmic reticulum stress- (ERS-) related proteins were evaluated through real-time quantitative PCR, western blotting, immunohistochemistry, and TUNEL staining. The levels of inflammatory cytokines were measured through the enzyme-linked immunosorbent assay. Results: RNA-seq revealed that BCL-3 acts as a key player. BCL-3 promotes ICH progression by increasing BBB permeability, ERS, inflammation, and cell apoptosis. Silencing of BCL-3 slows ICH progression by reducing BBB permeability and inflammation and terminating cell apoptosis and ERS in vitro and in vivo. Conclusion: Our study identified ICH biomarkers and elucidated the role of BCL-3 in ICH for the first time.

Fusing perylene diimide with helicenes.

Incorporating perylene diimide (PDI) units into helicene structures has become a useful strategy for giving access to non-planar electron acceptors as well as a method of creating molecules with unique and intriguing chiroptical properties. This minireview describes this fusion of PDIs with helicenes.

Integrated transcriptomics and metabolomics analysis provide insight into anthocyanin biosynthesis for sepal color formation in Heptacodium miconioides.

Heptacodium miconioides Rehd., commonly known as "seven-son flower," is an ornamental species with a beautiful flower pattern and persistent sepals. Its sepals are of horticultural value, turning bright red and elongating in the autumn; however, the molecular mechanisms that cause sepal color change remain unclear. We analyzed the dynamic changes in anthocyanin composition in the sepal of H. miconioides at four developmental stages (S1-S4). A total of 41 anthocyanins were detected and classified into 7 major anthocyanin aglycones. High levels of the pigments cyanidin-3,5-O-diglucoside, cyanidin-3-O-galactoside, cyanidin-3-O-glucoside, and pelargonidin-3-O-glucoside were responsible for sepal reddening. Transcriptome analysis revealed 15 differentially expressed genes involved in anthocyanin biosynthesis that were detected between 2 developmental stages. Of these, the high expression of HmANS was considered critical structural gene related to anthocyanin biosynthesis pathway in the sepal through co-expression analysis with anthocyanin content. In addition, a transcription factor (TF)-metabolite correlation analysis revealed that three HmMYB, two HmbHLH, two HmWRKY, and two HmNAC TFs exhibited a strong positive role in the regulation of the anthocyanin structural genes (Pearson's correlation coefficient > 0.90). Luciferase activity assay showed that HmMYB114, HmbHLH130, HmWRKY6, and HmNAC1 could activate the promoters of HmCHS4 and HmDFR1 genes in vitro. These findings increase our understanding of anthocyanin metabolism in the sepal of H. miconioides and provide a guide for studies involving sepal color conversion and regulation.

Coaxially Conductive Organic Wires Through Self-Assembly.

Here, we describe the synthesis of the hexameric macrocyclic aniline (MA[6]), which spontaneously assembles into coaxially conductive organic wires in its oxidized and acidified emeraldine salt (ES) form. Electrical measurements reveal that ES-MA[6] exhibits high electrical conductivity (7.5 × 10-2 S·cm-1) and that this conductivity is acid-base responsive. Single-crystal X-ray crystallography reveals that ES-MA[6] assembles into well-defined trimeric units that then stack into nanotubes with regular channels, providing a potential route to synthetic nanotubes that are leveraged for ion or small molecule transport. Ultraviolet-visible-near-infrared absorbance spectroscopy and electron paramagnetic spectroscopy showcase the interconversion between acidic (conductive) and basic (insulating) forms of these macrocycles and how charge carriers are formed through protonation, giving rise to the experimentally observed high electrical conductivity.

Remote Control of Dynamic Twistacene Chirality.

We report a reliable way to manipulate the dynamic, axial chirality in perylene diimide (PDI)-based twistacenes. Specifically, we reveal how chiral substituents on the imide position induce the helicity in a series of PDI-based twistacenes. We demonstrate that this remote chirality is able to control the helicity of flexible [4]helicene subunits by UV-vis, CD spectroscopy, X-ray crystallography, and TDDFT calculations. Furthermore, we have discovered that both the chiral substituent and the solvent each has a strong impact on the sign and intensity of the CD signals, highlighting the control of the dynamic helicity in this flexible system. DFT calculations suggest that the steric interaction of the chiral substituents is the important factor in how well a particular group is at inducing a preferred helicity.

Single-Handed Helicene Nanoribbons via Transfer of Chiral Information.

Here we show the access to single-handed helicene nanoribbons by utilizing a [6]helicene building block to induce diastereoselective, photochemical formation of [5]helicene units. Specifically, we have synthesized nanoribbons P1 and P2 with different ratios of [6]helicene "sergeants" to [5]helicene "soldiers", which on average consist of between ∼50 and 60 ortho-annulated benzene rings. These are the longest, optically active helicene backbones that have been prepared to date. The chiroptic properties of P1 and P2 reveal the transfer of stereochemical information from "sergeants" to "soldiers". To gain further insight into the stereo-information relay, we apply the same molecular design to discrete, model oligomers 1-5 and confirm that they also preferentially adopt homochiral geometries.

Electronic Materials: An Antiaromatic Propeller Made from the Four-Fold Fusion of Tetraoxa[8]circulene and Perylene Diimides.

The synthesis of an antiaromatic tetraoxa[8]circulene annulated with four perylene diimides (PDI), giving a dynamic non-planar π-conjugated system, is described. The molecule contains 32 aromatic rings surrounding one formally antiaromatic planarized cyclooctatetraene (COT). The intense absorption (ϵ=3.35×105  M-1 cm-1 in CH2 Cl2 ) and emission bands are assigned to internal charge-transfer transitions in the combined PDI-circulene π-system. The spectroscopic data is supported by density functional theory calculations, and nuclear independent chemical shift calculation indicate that the antiaromatic COT has increased aromaticity in the reduced state. Electrochemical studies show that the compound can reversibly reach the tetra- and octa-anionic states by reduction of the four PDI units, and the deca-anionic state by reduction of the central COT ring. The material functions effectively in bulk hetero junction solar cells as a non-fullerene acceptor, reaching a power conversion efficiency of 6.4 %.

Photosynthesis, Nitrogen Allocation, Non-Structural Carbohydrate Allocation, and C:N:P Stoichiometry of Ulmus elongata Seedlings Exposed to Different Light Intensities.

The leaf photosynthetic capacity, leaf N partitioning, non-structural carbohydrate content, C, N, and P contents of endangered U. elongata seedlings exposed to different light intensities were compared in this study. The most favorable light condition for the survival and growth of U. elongata seedlings in the present study was 100% full sunlight, as this induced higher Pn, PNUE, PC, PR, PB, and NSC content relative to shade-treated seedlings. PNUE, PR, PC, and PB in U. elongata seedling leaves decreased under 40% and 10% full sunlight, while PL increased, indicating that shade increased the light capture efficiency of photosystem (PS) II but decreased electron transfer from PSII to PSI. Furthermore, leaf N content increased with shade intensity, revealing an adaptive strategy for poor light environments. Additionally, the smallest leaf biomass, Pn, WUE, and CE values and C:N and C:P ratios in stems and leaves were observed under 10% full sunlight. These results indicate that seedlings growing under 40% full sunlight will benefit U. elongata conservation.

Phytochemical and biological studies on rare and endangered plants endemic to China. Part XXV. Structurally diverse triterpenoids and diterpenoids from two endangered Pinaceae plants endemic to the Chinese Qinling Mountains and their bioactivities.

A joint phytochemical investigation on the MeOH extracts of the twigs and needles of two endangered Pinaceae plants endemic to the Chinese Qinling Mountains, Picea neoveitchii (an evergreen spruce) and Larix potaninii var. chinensis (a deciduous larch), led to the isolation and characterization of 34 and 24 structurally diverse terpenoids, respectively. Among them, seven are previously undescribed, including a picane-type [i.e., 14(13 â†’ 12)abeo-12αH-serratane] (neoveitchin A) and a serratane-type (neoveitchin B) triterpenoids, and an abietane-type (neoveitchin C) as well as four labdane-type (potalarxins A-D) diterpenoids. Their structures and absolute configurations were established by extensive spectroscopic methods and/or X-ray diffraction analyses. All isolates were evaluated for their inhibitory activities against the human protein tyrosine phosphatase 1B (PTP1B). Serrat-14-en-3α,21ß-diol, betulinic acid, 3ß-hydroxy-11-ursen-13(28)-olide, ursolic acid, and oleanolic acid were found to have considerable inhibitory effects against PTP1B, with IC50 values ranging from 1.1 to 18.1 µM. The interactions of the bioactive triterpenoids with PTP1B were thereafter performed by employing molecular docking studies. In addition, 7-oxo-dehydroabietic acid (an abietane-type diterpenoid) and mangiferonic acid (a cycloartane-type triterpenoid) inhibited acetyl-coenzyme A carboxylase 1 (ACC1), with IC50 values of 3.4 and 6.6 µM, respectively.

Iterative Synthesis of Contorted Macromolecular Ladders for Fast-Charging and Long-Life Lithium Batteries.

We report here an iterative synthesis of long helical perylene diimide (hPDI[n]) nanoribbons with a length up to 16 fused benzene rings. These contorted, ladder-type conjugated, and atomically precise nanoribbons show great potential as organic fast-charging and long-lifetime battery cathodes. By tuning the length of the hPDI[n] oligomers, we can simultaneously modulate the electrical conductivity and ionic diffusivity of the material. The length of the ladders adjusts both the conjugation for electron transport and the contortion for lithium-ion transport. The longest oligomer, hPDI[6], when fabricated as the cathode in lithium batteries, features both high electrical conductivity and high ionic diffusivity. This electrode material exhibits a high power density and can be charged in less than 1 min to 66% of its maximum capacity. Remarkably, this material also has exceptional cycling stability and can operate for up to 10,000 charging-discharging cycles without any appreciable capacity decay. The design principles described here chart a clear path for organic battery electrodes that are sustainable, fast-charging, and long lasting.

Synthesis of Contorted Polycyclic Conjugated Hydrocarbons via Regioselective Activation of Cyclobutadienoids.

Contorted carbon structures have drawn much attention in the past decade for their rich three-dimensional geometries, enhanced solubility, and tunable electronic properties. We report a modular method to synthesize contorted polycyclic conjugated hydrocarbons containing helical moieties in controlled topologies. This strategy leverages our previously reported streamlined synthesis of π-systems containing four-membered cyclobutadienoids (CBDs), whose catalyzed cycloaddition with alkynes affords helical structures. Interestingly, we observed exclusive nonbay region regioselectivity in the C-C bond activation of CBDs in our system, which is opposite to the scarce previous examples of [N]phenylene activation that led to the formation of linear phenacene structures. The quantitative and regioselective nonbay region alkyne cycloaddition yielded a variety of helical carbon structures with their topologies predetermined by the CBD-containing precursor hydrocarbons. The cycloaddition can be inhibited by methyl substituents exocyclic to the four-membered ring, thus allowing selective activation of only certain desired CBD units while leaving the others intact. Calculation elucidated the basis for the observed regioselectivity. The described method provides a new route to multihelical aromatic hydrocarbons with complex yet defined geometries, facilitating the further exploration of such fascinating carbon structures.

Complete chloroplast genome of Lonicera crassifolia Batalin (Caprifoliaceae) and its phylogenetic implications.

Lonicera crassifolia is a prostrate or creeping, evergreen Lonicera species endemic to southwest China. Here, we reported the complete chloroplast (cp) genome of L. crassifolia (GenBank accession number: OK393707). The cp genome was 154,731 bp long, with a large single-copy region (LSC) of 88,619 bp and a small single-copy region (SSC) of 18,642 bp separated by a pair of inverted repeats (IRs) of 23,735 bp. It encodes 130 genes, including 85 protein-coding genes, 37 tRNA genes, and 8 ribosomal RNA genes. We also reconstructed the phylogeny of Lonicera using the maximum-likelihood (ML) method, including our data and previously reported cp genomes of related taxa. The phylogenetic analysis showed that L. crassifolia is a sister to the remaining Nintooa clade with strong bootstrap support.

[Effects of arbuscular mycorrhizal fungi inoculation on non-structural carbohydrate contents and C:N:P stoichiometry of Heptacodium miconioides under drought stress]. / å¹²æ—±èƒè¿«ä¸‹æŽ¥ç§ä¸›æžèŒæ ¹çœŸèŒå¯¹ä¸ƒå­èŠ±éžç»“æž„æ€§ç¢³æ°´åŒ–åˆç‰©ç§¯ç´¯åŠC、N、P化学计量特征的影响.

A pot experiment was conducted to investigate the effects of drought stress and arbuscular mycorrhizal fungi (AMF) inoculation on C:N:P stoichiometry and non-structural carbohydrate (NSC) contents in two-year-old Heptacodium miconioides seedlings. There were four treatments, including control (CK), drought stress (D), AMF inoculation (AMF), and combined drought stress and AMF inoculation (D+AMF). The results showed that drought stress significantly reduced AMF colonization rate, whereas plant height and leaf number of inoculated treatment were significantly higher than the non-inoculated treatment. Inoculation with AMF significantly increased soluble sugar and NSC content in root and leaf, as well as starch content in stem and leaf. The inoculation significantly decreased the stem and leaf soluble sugar to starch ratio under drought stress. Drought stress caused a significant increase in C content in roots and leaves, and a significant decrease in P content in stems. Compared with no inoculation drought stress, P content in roots, stems, leaves, and C content in leaves of mycorrhizal seedlings were significantly increased by inoculation under drought stress, whereas root C and N content and stem C content were significantly reduced. Under drought stress, AMF inoculation significantly decreased C:N, C:P, and N:P ratios in roots and stems, and N:P ratios in leaves of H. miconioides. P content in roots and leaves were significantly positively correlated with soluble sugar and NSC content. Stem P content was significantly positively correlated with starch and NSC content. N:P ratios in each organ was significantly negatively correlated with NSC content. In all, inoculation with AMF can improve the drought tolerance of H. miconioides seedling by increasing soluble sugar content in roots and leaves and the soluble sugar/starch ratio in roots, improving starch content in above-ground organs, promoting the P absorption, and reducing N:P ratios in each organ. Therefore, AMF colonization could improve the survival rate of H. miconioides seedling in dry environments.

Liriogerphines A-D, a Class of Sesquiterpene-Alkaloid Hybrids from the Rare Chinese Tulip Tree Plant.

Liriogerphines A-D (1-4, respectively), an unprecedented class of hybrids of germacranolide-type sesquiterpenoids and aporphine-type alkaloids, were isolated from the rare medicinal plant Liriodendron chinense. Their structures were elucidated by comprehensive spectroscopic analyses combined with electronic circular dichroism calculations and X-ray crystallographic data. Biosynthetically, an aza-Michael addition reaction is proposed to be involved in the assemblies of this class of hybrids. Compound 4 exhibited cytotoxicity against leukemia cells via inducing apoptosis and inhibiting Bcl-2 expression.

π-Conjugated redox-active two-dimensional polymers as organic cathode materials.

Redox-active two-dimensional polymers (RA-2DPs) are promising lithium battery organic cathode materials due to their regular porosities and high chemical stabilities. However, weak electrical conductivities inherent to the non-conjugated molecular motifs used thus far limit device performance and the practical relevance of these materials. We herein address this problem by developing a modular approach to construct π-conjugated RA-2DPs with a new polycyclic aromatic redox-active building block PDI-DA. Efficient imine-condensation between PDI-DA and two polyfunctional amine nodes followed by quantitative alkyl chain removal produced RA-2DPs TAPPy-PDI and TAPB-PDI as conjugated, porous, polycrystalline networks. In-plane conjugation and permanent porosity endow these materials with high electrical conductivity and high ion diffusion rates. As such, both RA-2DPs function as organic cathode materials with good rate performance and excellent cycling stability. Importantly, the improved design enables higher areal mass-loadings than were previously available, which drives a practical demonstration of TAPPy-PDI as the power source for a series of LED lights. Collectively, this investigation discloses viable synthetic methodologies and design principles for the realization of high-performance organic cathode materials.