Global analysis of key post-transcriptional regulation in early leaf development of Limonium bicolor identifies a long non-coding RNA that promotes salt gland development and salt resistance.

Limonium bicolor, known horticulturally as sea lavender, is a typical recretohalophyte with salt glands in its leaf epidermis that secrete excess Na+ out of the plant. Although many genes have been proposed to contribute to salt gland initiation and development, a detailed analysis of alternative splicing, alternative polyadenylation patterns, and long non-coding RNAs (lncRNAs) has been lacking. Here, we applied single-molecule long-read mRNA isoform sequencing (Iso-seq) to explore the complexity of the L. bicolor transcriptome in leaves during salt gland initiation (stage A) and salt gland differentiation (stage B) based on the reference genome. We identified alternative splicing events and the use of alternative poly(A) sites unique to stage A or stage B, leading to the hypothesis that they might contribute to the differentiation of salt glands. Based on the Iso-seq data and RNA in situ hybridization of candidate genes, we selected the lncRNA Btranscript_153392 for gene editing and virus-induced gene silencing to dissect its function. In the absence of this transcript, we observed fewer salt glands on the leaf epidermis, leading to diminished salt secretion and salt tolerance. Our data provide transcriptome resources for unraveling the mechanisms behind salt gland development and furthering crop transformation efforts towards enhanced survivability in saline soils.

AIE-ESIPT Photoluminescent Probe Based on 3-(3-Hydroxypyridin-2-yl)isoquinolin-4-ol for the Detection of Intracellular Hydrogen Peroxide.

Excited-state intramolecular proton transfer (ESIPT) molecules, which feature large Stokes shifts to avoid self-absorption, play an essential role in photoluminescent bioimaging probes. Herein, we report the development of an ESIPT molecule 3-(3-hydroxypyridin-2-yl)isoquinolin-4-ol (PiQ). PiQ not only undergoes a distinct ESIPT process unlike the symmetrical 2,2'-bipyridyl-3,3'-diol but also exhibits aggregation-induced emission (AIE) characteristics. PiQ self-assembles into aggregates with an average size of 241.0±51.9 nm in aqueous solutions, leading to significantly enhanced photoluminescence. On the basis of the ESIPT and AIE characteristics of PiQ, the latter is functionalized with a hydrogen peroxide-responsive 4-pinacoratoborylbenzyl group (B) and a carboxylesterase-responsive acetyl group (A) to produce a photoluminescent probe B-PiQ-A. The potential of PiQ for applications in bioimaging and chemical sensing is underscored by its efficient detection of both endogenous and exogenous hydrogen peroxide in living cells.

Electronic Structure Modulation Via Iron-Incorporated NiO to Boost Urea Oxidation/Oxygen Evolution Reaction.

The urea-assisted water splitting not only enables a reduction in energy consumption during hydrogen production but also addresses the issue of environmental pollution caused by urea. Doping heterogeneous atoms in Ni-based electrocatalysts is considered an efficient means for regulating the electronic structure of Ni sites in catalytic processes. However, the current methodologies for synthesizing heteroatom-doped Ni-based electrocatalysts exhibit certain limitations, including intricate experimental procedures, prolonged reaction durations, and low product yield. Herein, Fe-doped NiO electrocatalysts were successfully synthesized using a rapid and facile solution combustion method, enabling the synthesis of 1.1107 g within a mere 5 min. The incorporation of iron atoms facilitates the modulation of the electronic environment around Ni atoms, generating a substantial decrease in the Gibbs free energy of intermediate species for the Fe-NiO catalyst. This modification promotes efficient cleavage of C-N bonds and consequently enhances the catalytic performance of UOR. Benefiting from the tunability of the electronic environment around the active sites and its efficient electron transfer, Fe-NiO electrocatalysts only needs 1.334 V to achieve 50 mA cm-2 during UOR. Moreover, Fe-NiO catalysts were integrated into a dual electrode urea electrolytic system, requiring only 1.43 V of cell voltage at 10 mA cm-2.

MMP-2-Activatable Photoacoustic Tumor Imaging Probes Based on Al- and Si-Naphthalocyanines.

Enzyme-activatable photoacoustic probes are powerful contrast agents to visualize diseases in which a specific enzyme is overexpressed. In this study, aluminum and silicon naphthalocyanines (AlNc and SiNc, respectively) conjugated with matrix metalloprotease-2 (MMP-2)-responsive PLGLAG peptide sequence and poly(ethylene glycol) (PEG) as an axial ligand were designed and synthesized. AlNc-peptide-PEG conjugates AlNc-pep-PEG formed dimeric species interacting with each other through face-to-face H-aggregation in water, while SiNc-based conjugates SiNc-pep-PEG hardly interacted with each other because of the two bulky hydrophilic axial ligands. Both conjugates formed spherical nanometer-sized self-assemblies in water, generating photoacoustic waves under near-infrared photoirradiation. The treatment of MNc-peptide-PEG conjugates (M = Al, Si) with MMP-2 smoothly induced the cleavage of the PLGLAG sequence to release the hydrophilic PEG moiety, resulting in the aggregation of MNcs. By comparing the PA signal intensity changes at 680 and 760 nm, the photoacoustic signal intensity ratios were shown to be enhanced by 3-5 times after incubation with MMP-2. We demonstrated that MNc-peptide-PEG conjugates (M = Al, Si) could work as activatable photoacoustic probes in the in vitro experiment of MMP-2-overexpressed cell line HT-1080 as well as the in vivo photoacoustic imaging of HT-1080-bearing mice.

One-step synthesis, electronic structure, and photocatalytic activity of earth-abundant visible-light-driven FeAl2O4.

The development of inexpensive visible-light-driven photocatalysts is an important prerequisite for realizing the industrial application of photocatalysis technology. In this paper, an earth-abundant FeAl2O4 photocatalyst is prepared via facile solution combustion synthesis. Density functional theory and the scanning Kelvin probe technique are employed to ascertain the positions of the energy bands and the Fermi level. Phenol is taken as a model pollutant to evaluate the photocatalytic activity of FeAl2O4. The scavenger experiment results, ˙OH-trapping fluorescence technique, and electron spin resonance measurements confirm that the superoxide anion radical is the main active species generated in the photocatalytic process, which also further corroborates the proposed electronic structure of FeAl2O4. The degradation experiments and O2 temperature programmed desorption results over various samples verify that the crystallinity degree is a more important factor than the oxygen adsorption ability in determining photocatalytic activity.

Association between ERCC2 rs13181 polymorphism and ovarian cancer risk: an updated meta-analysis with 4024 subjects.

BACKGROUND: Genetic variants in the excision repair cross-complimentary group 2 (ERCC2) gene may affect individual susceptibility to cancer by modulating the capability of DNA damage repair. However, the current studies concerning the association of ERCC2 rs13181 polymorphism with ovarian cancer risk provided inconsistent evidence. METHODS: This study was to quantitatively summarize the evidence from the individual studies electronically retrieved by a meta-analysis. RESULTS: Totally, nine eligible case-control studies with 1333 cases and 2691 controls were included for the concerned association. Overall, a significant association between ERCC2 gene rs13181 polymorphism and increased risk of ovarian cancer was revealed (CC+AC vs. AA: OR 1.44, 95% CI 1.11-1.86; CC vs. AA: OR 2.12, 95% CI 1.14-3.97). Similarly, in the subgroup analyses, such association was also evident in non-Caucasian population and hospital-based studies. Noteworthily, the recombined analysis with a significant decrease in between-heterogeneity represented a significant association of the variant with increased risk of ovarian cancer after excluding the individual study not in agreement with HWE. CONCLUSION: The present study suggests that the ERCC2 gene rs13181 polymorphism might be associated with increased risk of ovarian cancer.

Light up ClO(-) in live cells using an aza-coumarin based fluorescent probe with fast response and high sensitivity.

Hypochlorous acid (HClO)/hypochlorite (ClO(-)), one of the reactive oxygen species (ROS), is a key microbicidal agent used for natural defense; however, HClO is also responsible for some human diseases. Although much effort has been made to develop HClO-selective fluorescent probes, many of them display a delayed response time and nanomole-sensitive probes are rare. In this study, we designed and synthesized an aza-coumarin based fluorescent probe AC-ClO for ClO(-) determination with fast response (completed within 2 min) and high sensitivity (detection limit is 25 nM). AC-ClO displayed a color change from pink to light yellow and a remarkable "turn-on" fluorescence response towards ClO(-). Confocal fluorescence microscopy experiments demonstrated that the probe could be applied for the live-cell imaging of exogenous and endogenous ClO(-).

Ratiometric fluorescence imaging of cellular polarity: decrease in mitochondrial polarity in cancer cells.

Mitochondrial polarity strongly influences the intracellular transportation of proteins and interactions between biomacromolecules. The first fluorescent probe capable of the ratiometric imaging of mitochondrial polarity is reported. The probe, termed BOB, has two absorption maxima (λabs = 426 and 561 nm) and two emission maxima--a strong green emission (λem = 467 nm) and a weak red emission (642 nm in methanol)--when excited at 405 nm. However, only the green emission is markedly sensitive to polarity changes, thus providing a ratiometric fluorescence response with a good linear relationship in both extensive and narrow ranges of solution polarity. BOB possesses high specificity to mitochondria (Rr =0.96) that is independent of the mitochondrial membrane potential. The mitochondrial polarity in cancer cells was found to be lower than that of normal cells by ratiometric fluorescence imaging with BOB. The difference in mitochondrial polarity might be used to distinguish cancer cells from normal cells.

An "enhanced PET"-based fluorescent probe with ultrasensitivity for imaging basal and elesclomol-induced HClO in cancer cells.

Reactive oxygen species (ROS) and cellular oxidant stress have long been associated with cancer. Unfortunately, the role of HClO in tumor biology is much less clear than for other ROS. Herein, we report a BODIPY-based HClO probe (BClO) with ultrasensitivity, fast response (within 1 s), and high selectivity, in which the pyrrole group at the meso position has an "enhanced PET" effect on the BODIPY fluorophore. The detection limit is as low as 0.56 nM, which is the highest sensitivity achieved to date. BClO can be facilely synthesized by a Michael addition reaction of acryloyl chloride with 2,4-dimethylpyrrole and applied to image the basal HClO in cancer cells for the first time and the time-dependent HClO generation in MCF-7 cells stimulated by elesclomol, an effective experimental ROS-generating anticancer agent.

Highly sensitive naphthalene-based two-photon fluorescent probe for in situ real-time bioimaging of ultratrace cyclooxygenase-2 in living biosystems.

Detecting and imaging of ultratrace cyclooxygenase-2 in living biosystems could provide much important valuable information for the diagnosis and intervention of cancer. Molecular probes, whose fluorescent signals are generated by cyclooxygenase-2, hold great potential for identification and enumeration of cyclooxygenase-2 in living biosystems. Although quite a few fluorescent probes have been reported for cyclooxygenase-2, the use fluorogenic probe with the excellent two-photon properties for the determination of ultratrace cyclooxygenase-2 has been scarce. Herein, an "off-on" fluorescence probe (BTDAN-COX-2), able to report and image the presence of ultratrace cyclooxygenase-2 in living biosystems, has been designed and evaluated. In order to improve sensitivity and specific selectivity of probe for ultratrace cyclooxygenase-2, BTDAN-COX-2 employed cyclooxygenase-2's inhibitor as recognition group, because it is a classical and efficient recognition group for cyclooxygenase-2. A polarity-sensitive naphthalene derivative (BTDAN) as fluorophore was introduced into the molecule to enhance two-photon properties of BTDAN-COX-2. In the absent of cyclooxygenase-2, BTDAN-COX-2 mainly exists in a folded conformation where probe fluorescence is quenched through photoinduced electron transfer between the fluorophore and the recognition group. Under the condition of existence of cyclooxygenase-2, fluorescence of probe is turned on, because photoinduced electron transfer between the fluorophore and the recognition group is restrained. BTDAN-COX-2 provides high signal-to-background staining for the ultratrace cyclooxygenase-2 and has been successfully used to rapidly detect and image ultratrace cyclooxygenase-2 in living biosystems.

A reductively convertible nickel phthalocyanine precursor as a biological thiol-responsive turn-on photoacoustic contrast agent.

A nickel phthalocyanine precursor bearing poly(ethylene glycol) as a turn-on contrast agent for photoacoustic imaging was prepared. The water-soluble polymeric chains were smoothly eliminated through thiol-mediated reductive aromatization in cancer cells, enabling the detection of endogenous biological thiols in vitro and in vivo.

Dual-responsive near-infrared turn-on fluorescent probe for cancer stem cell-specific visualization.

Aldehyde dehydrogenase 1A1 (ALDH1A1) stands out as one of the most reliable intracellular biomarkers for stem cells because it is expressed in both cancer stem cells (CSCs) and normal somatic stem cells (NSCs). Although several turn-on fluorescent probes for ALDH1A1 have been developed to visualize CSCs in cancer cells, the discrimination of CSCs from NSCs is difficult. We here report an AND-type dual-responsive fluorescent probe, CHO_ßgal, the near-infrared fluorescence of which can be turned on after responding to both ALDH1A1 and ß-galactosidase. The AND-type dual responsiveness enables CSCs to be clearly visualized, whereas NSCs are non-emissive in microscopy. CSC-positive metastasis model lungs were successfully discriminated from normal lungs in ex vivo staining experiments using CHO_ßgal, whereas the single-input ALDH1A1-responsive probe failed to achieve this discrimination owing to pronounced false-positive fluorescence output from lung NSCs. In tissue slice staining experiments, even in the presence of adjacent normal tissues, the peripheral region-specific localization of CSCs was clear. The versatility of CHO_ßgal holds promise not only as a fundamental in vitro research tool for visualizing CSCs but also as a valuable asset in practical tissue staining diagnosis, significantly contributing to the assessment of cancer malignancy.

Light-controllable cell-membrane disturbance for intracellular delivery.

Highly polar and charged molecules, such as oligonucleotides, face significant barriers in crossing the cell membrane to access the cytoplasm. To address this problem, we developed a light-triggered twistable tetraphenylethene (TPE) derivative, TPE-C-N, to facilitate the intracellular delivery of charged molecules through an endocytosis-independent pathway. The central double bond of TPE in TPE-C-N is planar in the ground state but becomes twisted in the excited state. Under light irradiation, this planar-to-twisted structural change induces continuous cell membrane disturbances. Such disturbance does not lead to permanent damage to the cell membrane. TPE-C-N significantly enhanced the intracellular delivery of negatively charged molecules under light irradiation when endocytosis was inhibited through low-temperature treatment, confirming the endocytosis-independent nature of this delivery method. We have successfully demonstrated that the TPE-C-N-mediated light-controllable method can efficiently promote the intracellular delivery of charged molecules, such as peptides and oligonucleotides, with molecular weights ranging from 1000 to 5000 Da.

Bioinformatics in Plant Breeding and Research on Disease Resistance.

In the context of plant breeding, bioinformatics can empower genetic and genomic selection to determine the optimal combination of genotypes that will produce a desired phenotype and help expedite the isolation of these new varieties. Bioinformatics is also instrumental in collecting and processing plant phenotypes, which facilitates plant breeding. Robots that use automated and digital technologies to collect and analyze different types of information to monitor the environment in which plants grow, analyze the environmental stresses they face, and promptly optimize suboptimal and adverse growth conditions accordingly, have helped plant research and saved human resources. In this paper, we describe the use of various bioinformatics databases and algorithms and explore their potential applications in plant breeding and for research on plant disease resistance.

Steric Control in Activator-Induced Nucleophilic Quencher Detachment-Based Probes: High-Contrast Imaging of Aldehyde Dehydrogenase 1A1 in Cancer Stem Cells.

Turn-on fluorescence probes can visualize the enzyme activity with high contrast. We have established a new turn-on mechanism, activator-induced nucleophilic quencher detachment (AiQd), and developed AiQd-based turn-on fluorescence probes for the detection of enzymes. Herein, we demonstrate that the precise steric control efficiently quenches the fluorescence of AiQd-based turn-on probes before the enzymatic transformation. Theoretical calculation appropriately predicted the ratio of the fluorescence-quenched closed-ring form of probes. ßC5S-A, which has a sterically demanding methyl group at the ß-position of a fluorescence-quenching nucleophilic mercapto group, showed a low background signal. ßC5S-A responded to aldehyde dehydrogenase 1A1 (ALDH1A1) with high selectivity, thereby enabling high-contrast live imaging of cancer stem cells (signal-to-noise ratio >10). The ALDH1A1-responsiveness of ßC5S-A was not significantly affected by amino acids and biological thiols, such as cysteine and glutathione.

Substituted meso-vinyl-BODIPY as thiol-selective fluorogenic probes for sensing unfolded proteins in the endoplasmic reticulum.

A new type of thiol probes based on the meso-vinyl-BODIPY (VB) scaffold were developed. The monochloro-substituted VB1Cl exhibited the largest fluorescence enhancement (>200-fold) as well as high selectivity upon biological thiol sensing. VB1Cl was successfully applied for reporting the protein unfolding process under ER stress in living cells.

Aluminum naphthalocyanine conjugate as an MMP-2-activatable photoacoustic probe for in vivo tumor imaging.

Matrix metalloproteinase-2 (MMP-2), which is one of MMPs family, is known as an extracellular gelatinase controlling cancer cell adhesion, growth, and metastasis. Because of the great interest in MMP-2 activity, the detailed protocols for evaluating MMP-2-responsive contrast agents, especially photoacoustic probes for in vivo use, are helpful for researchers in the field. We here describe the detailed synthetic procedure of MMP-2-activatable photoacoustic probe AlNc-pep-PEG consisting of aluminum naphthalocyanine, MMP-2-responsive peptide sequence, and poly(ethylene glycol), which has recently been developed in our research group. The detailed measurement protocol of photoacoustic signal intensity in vitro and in vivo by using in-house built photoacoustic signal measurement system and photoacoustic imaging apparatus are also summarized.

pH-Activatable Cyanine Dyes for Selective Tumor Imaging Using Near-Infrared Fluorescence and Photoacoustic Modalities.

Photoacoustic (PA) imaging is an emerging molecular imaging modality that complements fluorescence imaging and enables high resolution within deep tissue. Fluorescence/PA multimodality imaging would be a powerful technique to extract more comprehensive information from targets than traditional single-modality imaging. In this paper, we developed a new pH-activatable sensor, CypHRGD, which is applicable to both fluorescence and PA detection. CypHRGD was derived from our previous near-infrared pH-sensing platform, in which substitution with a bulky phenyl group and functionalization with a cRGD peptide remarkably improved the sensor's biocompatibility with attenuated dye aggregation. The multimodality imaging applications of CypHRGD were demonstrated in cultured cells and cancer-xenografted mice with rapid kinetics and high sensitivity and specificity, which relies on cRGD-facilitated tumor targeting, probe accumulation and subsequent activation in the acidic organelles after endocytosis.

The simultaneous adsorption, activation and in situ reduction of carbon dioxide over Au-loading BiOCl with rich oxygen vacancies.

The main process of carbon dioxide (CO2) photoreduction is that excited electrons are transported to surface active sites to reduce adsorbed CO2 molecules. Obviously, electron transfer to the active site is one of the key steps in this process. However, current catalysts for CO2 adsorption, activation, and electron reduction occur in different locations, which greatly reduce the efficiency of photocatalysis. Herein, through a spontaneous chemical redox approach, the plasmonic photocatalysts of Au-BiOCl-OV with enhanced interfacial interaction were fabricated for visible light CO2 reduction through the simultaneous adsorption, activation and in situ reduction of CO2 without a sacrificial agent. By loading gold (Au) on the oxygen vacancy (OV), Au and BiOCl-OV formed a direct and tight interface contact, whose fine structure was confirmed by SEM, TEM, EPR and XPS, which not only effectively boosts the light utilization efficiency and the light carrier separation ability, but also can simultaneously adsorb, activate and in situ reduce carbon dioxide for highly efficient visible light photocatalysis. Thanks to the synergistic influence of Au and OV, Au-BiOCl-OV exhibits excellent photocatalytic performance without sacrificial agent and outstanding stability with a high CO and CH4 production yield, reaching 4.85 µmol g-1 h-1, which were 2.8 times higher than C-Au-BiOCl-OV (obtained by traditional NaBH4 reduction). This study proposes a new strategy for the production of high-performance collaborative catalysis in photocatalytic CO2 reduction.

Valley Polarization and Valleyresistance in a Monolayer Transition Metal Dichalcogenide Superlattice.

A significant, fundamental challenge in the field of valleytronics is how to generate and regulate valley-polarized currents in practical ways. Here, we discover a new mechanism for producing valley polarization in a monolayer transition metal dichalcogenide superlattice, in which valley-resolved gaps are formed at the supercell Brillouin zone boundaries and centers due to intervalley scattering. When the incident energy of the electron lies in the gaps, the available states are valley polarized, thus providing a valley-polarized current from the superlattice. We show that the direction and strength of the valley polarization may be further tuned by varying the potential applied to the superlattice. The transmission can have a net valley polarization of 55% for a four-period heterostructure. Moreover, two such valley filters in series may function as an electrostatically controlled giant valleyresistance device, representing a zero-magnetic field counterpart to the familiar giant magnetoresistance device.