Membralin is required for maize development and defines a branch of the endoplasmic reticulum-associated degradation pathway in plants.

Endoplasmic reticulum (ER)-associated degradation (ERAD) plays key roles in controlling protein levels and quality in eukaryotes. The Ring Finger Protein 185 (RNF185)/membralin ubiquitin ligase complex was recently identified as a branch in mammals and is essential for neuronal function, but its function in plant development is unknown. Here, we report the map-based cloning and characterization of Narrow Leaf and Dwarfism 1 (NLD1), which encodes the ER membrane-localized protein membralin and specifically interacts with maize homologs of RNF185 and related components. The nld1 mutant shows defective leaf and root development due to reduced cell number. The defects of nld1 were largely restored by expressing membralin genes from Arabidopsis thaliana and mice, highlighting the conserved roles of membralin proteins in animals and plants. The excessive accumulation of ß-hydroxy ß-methylglutaryl-CoA reductase in nld1 indicates that the enzyme is a membralin-mediated ERAD target. The activation of bZIP60 mRNA splicing-related unfolded protein response signaling and marker gene expression in nld1, as well as DNA fragment and cell viability assays, indicate that membralin deficiency induces ER stress and cell death in maize, thereby affecting organogenesis. Our findings uncover the conserved, indispensable role of the membralin-mediated branch of the ERAD pathway in plants. In addition, ZmNLD1 contributes to plant architecture in a dose-dependent manner, which can serve as a potential target for genetic engineering to shape ideal plant architecture, thereby enhancing high-density maize yields.

Abscisic acid root-to-shoot translocation by transporter AtABCG25 mediates stomatal movements in Arabidopsis.

The phytohormone abscisic acid (ABA) plays a central role in regulating stomatal movements under drought conditions. The root-derived peptide CLAVATA3/EMBRYO SURROUNDING REGION-RELATED 25 (CLE25) moves from the root to shoot for activating ABA biosynthesis under drought conditions. However, the root-to-shoot translocation of root-derived ABA and its regulation of stomatal movements in the shoot remain to be clarified. Here, we reveal that the ABA transporter ATP-binding cassette subfamily G member 25 (AtABCG25) mediates root-to-shoot translocation of ABA and ABA-glucosyl ester (ABA-GE) in Arabidopsis (Arabidopsis thaliana). Isotope-labeled ABA tracer experiments and hormone quantification in xylem sap showed that the root-to-shoot translocation of ABA and ABA-GE was substantially impaired in the atabcg25 mutant under nondrought and drought conditions. However, the contents of ABA and ABA-GE in the leaves were lower in the atabcg25 mutant than in the wild type (WT) under nondrought but similar under drought conditions. Consistently, the stomatal closure was suppressed in the atabcg25 mutant under nondrought but not under drought conditions. The transporter activity assays showed that AtABCG25 directly exported ABA and ABA-GE in planta and in yeast (Saccharomyces cerevisiae) cells. Thus, we proposed a working model in which root-derived ABA transported by AtABCG25 via xylem mediates stomatal movements in the shoot under nondrought conditions but might exhibit little effect on stomatal movements under drought conditions. These findings extend the functions of AtABCG25 and provide insights into the long-distance translocation of ABA and its role in stomatal movements.

Sequential activation of strigolactone and salicylate biosynthesis promotes leaf senescence.

Leaf senescence is a complex process strictly regulated by various external and endogenous factors. However, the key signaling pathway mediating leaf senescence remains unknown. Here, we show that Arabidopsis SPX1/2 negatively regulate leaf senescence genetically downstream of the strigolactone (SL) pathway. We demonstrate that the SL receptor AtD14 and MAX2 mediate the age-dependent degradation of SPX1/2. Intriguingly, we uncover an age-dependent accumulation of SLs in leaves via transcriptional activation of SL biosynthetic genes by the transcription factors (TFs) SPL9/15. Furthermore, we reveal that SPX1/2 interact with the WRKY75 subclade TFs to inhibit their DNA-binding ability and thus repress transcriptional activation of salicylic acid (SA) biosynthetic gene SA Induction-Deficient 2, gating the age-dependent SA accumulation in leaves at the leaf senescence onset stage. Collectively, our new findings reveal a signaling pathway mediating sequential activation of SL and salicylate biosynthesis for the onset of leaf senescence in Arabidopsis.

Intelligent Gas Detection: g-C3N4/Polypyrrole Decorated Alginate Paper as Smart Selective NH3/NO2 Sensors at Room Temperature.

Chemiresistive NH3/NO2 sensors are attracting considerable attention for use in air-conditioning systems. However, the existing sensors suffer from cross-sensitivity, detection limit, and power consumption, owing to the inadequate charge-transfer ability of gas-sensing materials. Herein, we develop a flexible NH3/NO2 sensor based on graphitic carbon nitride/polypyrrole decorated alginate paper (AP@g-CN/PPy). The flexible sensor can work at room temperature and exhibits a positive response of 23-246% and a negative response of 37-262% toward 0.1-5 ppm of NH3 and NO2, which is ∼4.5 times and ∼7.0 times higher than a pristine PPy sensor. Moreover, the sensor exhibits flexibility, reproducibility, long-term stability, anti-interference, and high resilience to humidity, indicating its promising potential in real applications. Using the 9 feature parameters extracted from the transient response, a matched deep learning model was developed to achieve qualitative recognition of different types of gases with distinguished decision boundaries. This work not only provides an alternative gas-sensing material for dual NH3/NO2 sensing but also establishes an intelligent strategy to identify hazardous gases under an interfering atmosphere.

Flavin mononucleotide regulated photochemical isomerization and degradation of zeatin.

cis-Zeatin (cZ), a cytokinin often overlooked compared to trans-zeatin (tZ), can now be controlled in live cells and plants through a new biocompatible reaction. Using flavin photosensitizers, cZ can be isomerized to tZ or degraded, depending on the presence of a reducing reagent. This breakthrough offers a novel approach for regulating plant growth through chemical molecules.

Structure-dependent spin-polarized electron transport in twin-crystal Cu1-xEuxO semiconductors.

In this work, Eu-doped twin copper oxide (twin Cu1-xEuxO) was synthesized using the gas-liquid phase chemical deposition method in combination with high-temperature oxidation. The incorporation of Eu3+ ions was affected by their diffusivity and the related charge trapping mechanisms. The twin Cu1-xEuxO configuration exhibited significant room-temperature ferromagnetism. From our analysis, it was demonstrated that as the Eu3+ doping concentration increased, the saturation magnetization first increased and then gradually decreased, reaching a peak at 0.82 at%. A p-type to an n-type semiconducting transition was also recorded as the doping concentration increased. A significant anomalous Hall effect characterized by a maximum anomalous Hall coefficient of 1.65, and a maximum Hall conductivity mobility of 16.50 Ohm-1 cm-1 and 250.59 cm2 v-1 s-1, respectively, were derived for the twin Cu1-xEuxO, doped with 0.82 at% at room temperature. First-principles computational simulations were also conducted to elucidate the underlying mechanisms of the magnetic properties, the p-type to n-type transition, and the interplay between the spin-polarized states associated with 4f and carriers. In twin Cu1-xEuxO, the anomalous Hall effect originated from the contribution of the edge-to-jump scattering mechanism. The latter can be significantly enhanced by doping with Eu atoms, which yields the manifestation of the oblique scattering mechanism. Our work paves the way for the development of twin Cu1-xEuxO material structures, which emerge as an ideal candidate for future spintronic applications.

A Novel Ultrafiltrate Extract of Propolis Exerts Anti-inflammatory Activity through Metabolic Rewiring.

Thousands of years ago, humans started to use propolis because of its medicinal properties, and modern science has successfully identified several bioactive molecules within this resinous bee product. However, a natural propolis extract which has been removed the adhesive glue and preserved propolis bioactive compounds is urgently needed to maximise the therapeutic opportunities. In this study, a novel ultrafiltrate fraction from Brazilian green propolis, termed P30K, was demonstrated with anti-inflammatory properties, both in vitro and in vivo. Total flavonoids and total phenolic acids content in P30K were 244.6 mg/g and 275.8 mg/g respectively, while the IC50 value of inhibition of cyclooxygenase-2 (COX-2) was 8.30 µg/mL. The anti-inflammatory activity of P30K was furtherly corroborated in experimental models of lipopolysaccharides (LPS)-induced acute liver and lung injury. Mechanistically, integrated GC-MS and LC-MS based serum metabolomics analysis revealed that P30K modulated citrate cycle (TCA), pyruvate, glyoxylate and dicarboxylate metabolism pathways to inhibit secretion of pro-inflammatory cytokines. Results of network pharmacology and molecular docking suggested that P30K targeted catechol-O-methyltransferases (COMT), 11ß-hydroxysteroid dehydrogenases (HSD11B1), and monoamine oxidases (MAOA and MAOB) to promote cellular metabolomic rewiring. Collectively, our work reveals P30K as an efficient therapeutic agent against inflammatory conditions and its efficacy is related to metabolic rewiring.

Discrimination between raw and ginger juice processed Fructus Gardeniae based on UHPLC-Q-TOF-MS and Heracles NEO ultra-fast gas phase electronic nose.

INTRODUCTION: Fructus Gardeniae (ZZ), a traditional Chinese herb, has been used in treating patients with jaundice, inflammation, etc. When mixed with ginger juice and stir-baked, ginger juice-processed Fructus Gardeniae (JZZ) is produced, and the chemical compositions in ZZ would be changed by adding the ginger juice. OBJECTIVE: To illuminate the differential components between ZZ and JZZ. METHODS: HPLC, UHPLC-Q-TOF-MS, and Heracles NEO ultra-fast gas phase electronic nose were applied to identify the differential components between ZZ and JZZ. RESULTS: HPLC fingerprints of ZZ and JZZ were established, and 24 common peaks were found. The content determination results showed that the contents of shanzhiside, geniposidic acid, genipin-1-ß-D-gentiobioside and geniposide increased, while the contents of crocin I and crocin II decreased in JZZ. By UHPLC-Q-TOF-MS, twenty-six possible common components were inferred, among which 11 components were different. In further investigation, eight components were identified as the possible distinctive non-volatile compounds between ZZ and JZZ. By Heracles NEO ultra-fast gas phase electronic nose, four substances were inferred as the possible distinctive volatile compounds in JZZ. CONCLUSION: Shanzhiside, caffeic acid, genipin-1-ß-D-gentiobioside, geniposide, rutin, crocin I, crocin II, and 4-Sinapoyl-5-caffeoylquinic acid were identified as the possible differential non-volatile components between ZZ and JZZ. Aniline, 3-methyl-3-sulfanylbutanol-1-ol, E-3-octen-2-one, and decyl propaonate were inferred as the possible distinctive volatile compounds in JZZ. This experiment explored a simple approach with objective and stable results, which would provide new ideas for studying decoction pieces with similar morphological appearance, especially those with different odors.

Study on the quality difference between raw and ginger juice processed Magnoliae officinalis cortex by UPLC-Q-TOF-MS/MS and GC-MS coupled with color measurement.

INTRODUCTION: Magnoliae officinalis cortex (MOC) has been used for thousands of years as a traditional Chinese herb. In Chinese Pharmacopoeia (2020 edition), it has two types of decoction pieces, raw Magnoliae officinalis cortex (RMOC) and ginger juice processed Magnoliae officinalis cortex (GMOC). The quality difference between RMOC and GMOC has not been explored systemically. OBJECTIVE: This study aimed to discover the quality difference between RMOC and GMOC, and clarify the effect of ginger juice during processing comprehensively. METHODS: Ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS) and gas chromatography-mass spectrometry (GC-MS) were applied to study the non-volatile and volatile components of RMOC and GMOC; electronic eye was applied for color measurement. Meanwhile, water processed Magnoliae officinalis cortex (WMOC) was studied as the blank sample. RESULTS: There were 155 non-volatile and 72 volatile substances identified. Between RMOC and GMOC, 29 distinctive non-volatile and 34 distinctive volatile compounds were detected, among which 23 new compounds appeared and five compounds disappeared due to the addition of ginger juice during processing. The intensities of 12 common non-volatile compounds and the relative percentage contents of four common volatile compounds showed significant differences between RMOC and GMOC. In color measurement of RMOC, GMOC, and WMOC, 14 common compounds with significant differences were discovered related to their color values, and their mathematical prediction functions were built. CONCLUSION: There were significant differences between RMOC and GMOC; the processing mechanism of GMOC would be carried out based on the differential compounds in further investigation.

The Long-Distance Transport of Some Plant Hormones and Possible Involvement of Lipid-Binding and Transfer Proteins in Hormonal Transport.

Adaptation to changes in the environment depends, in part, on signaling between plant organs to integrate adaptive response at the level of the whole organism. Changes in the delivery of hormones from one organ to another through the vascular system strongly suggest that hormone transport is involved in the transmission of signals over long distances. However, there is evidence that, alternatively, systemic responses may be brought about by other kinds of signals (e.g., hydraulic or electrical) capable of inducing changes in hormone metabolism in distant organs. Long-distance transport of hormones is therefore a matter of debate. This review summarizes arguments for and against the involvement of the long-distance transport of cytokinins in signaling mineral nutrient availability from roots to the shoot. It also assesses the evidence for the role of abscisic acid (ABA) and jasmonates in long-distance signaling of water deficiency and the possibility that Lipid-Binding and Transfer Proteins (LBTPs) facilitate the long-distance transport of hormones. It is assumed that proteins of this type raise the solubility of hydrophobic substances such as ABA and jasmonates in hydrophilic spaces, thereby enabling their movement in solution throughout the plant. This review collates evidence that LBTPs bind to cytokinins, ABA, and jasmonates and that cytokinins, ABA, and LBTPs are present in xylem and phloem sap and co-localize at sites of loading into vascular tissues and at sites of unloading from the phloem. The available evidence indicates a functional interaction between LBTPs and these hormones.

Quantum capacitance induced by electron orbital reconstruction of g-C3N4/Co3O4 heterojunction: Improving electrochemical performance.

Utilizing diverse material combinations in heterogeneous structures has become an effective approach for regulating interface characteristics and electronic structures. The g-C3N4/Co3O4 heterostructures were fabricated by uniformly modifying Co3O4 nanoparticles onto discrete clusters of g-C3N4 nanosheets. Then, they were subsequently employed as positive electrode materials for assembling hybrid supercapacitors. According to the first-principles calculation, Co3O4 and g-C3N4 formed Co-N ionic bonds, establishing interfacial space symmetry-broken heterojunction and direct exchange and superexchange between ions at the interface and sub-interface. This resulted in a high-density spin-orbit hybrid heterogeneous polarization interface, significantly improving the quantum capacitance of heterojunction materials. Experimental results showed that the heterojunction had a specific capacitance of 2662 F g-1 at 1 A g-1. When the power density was 750 W kg-1, the energy density reached 128 Wh kg-1. Even when the power density was 16850 W kg-1, it could show an energy density of 62.5 Wh kg-1. The g-C3N4/Co3O4 heterojunction could realize high energy density charge storage as the cathode material of supercapacitors. The construction of heterogeneous polarization interfaces for high-energy quantum capacitors provides a new and effective method for the energy storage field.

Salidroside Reduced Ca2+-CaM-CAMKII-Dependent eNOS/NO Activation to Decrease Endothelial Cell Injury Induced by Cold Combined with Hypoxia.

To investigate vascular endothelium damage in rats exposed to hypoxic and cold and the effect of salidroside in protecting against this damage. A rat isolated aortic ring hypoxia/cold model was established to simulate exposure to hypoxic and cold. The levels of endothelial cell injury markers were measured by ELISA. TEM was performed to observe the ultrastructure of vascular ring endothelial cells. In vitro assays were performed to verify the effect of salidroside on endothelial cells. CCK-8 and flow cytometry were performed to analyze endothelial cell survival and apoptosis, respectively. Ca2+ concentrations were measured by Flow cytometry, and the expressions of NOS/NO pathway-related proteins were measured by WB. Endothelial cell damage, mitochondrial swelling, autophagy, and apoptosis were increased in the hypoxia group and hypoxia/hypothermia group. All of these effects were inhibited by salidroside. Moreover, exposure to cold combined with hypoxia reduced the NO levels, Ca2+ concentrations and NOS/NO pathway-related protein expression in the hypoxia group and hypoxia/hypothermia group. Salidroside treatment reversed these changes. Salidroside protected against endothelial cell injury induced by cold and hypoxia through reduction of Ca2+-CaM-CAMKII-dependent eNOS/NO activation, thereby preventing mitochondrial damage, reducing ROS levels, and inhibiting apoptosis.

Defect-Engineered WO3-x Architectures Coupled with Random Forest Algorithm Enables Real-Time Seafood Quality Assessment.

Reliable and real-time monitoring of seafood decay is attracting growing interest for food safety and human health, while it is still a great challenge to accurately identify the released triethylamine (TEA) from the complex volatilome. Herein, defect-engineered WO3-x architectures are presented to design advanced TEA sensors for seafood quality assessment. Benefiting from abundant oxygen vacancies, the obtained WO2.91 sensor exhibits remarkable TEA-sensing performance in terms of higher response (1.9 times), faster response time (2.1 times), lower detection limit (3.2 times), and higher TEA/NH3 selectivity (2.8 times) compared with the air-annealed WO2.96 sensor. Furthermore, the definite WO2.91 sensor demonstrates long-term stability and anti-interference in complex gases, enabling the accurate recognition of TEA during halibut decay (0-48 h). Coupled with the random forest algorithm with 70 estimators, the WO2.91 sensor enables accurate prediction of halibut storage with an accuracy of 95%. This work not only provides deep insights into improving gas-sensing performance by defect engineering but also offers a rational solution for reliably assessing seafood quality.

Spatially distributed cytokinins: Metabolism, signaling, and transport.

Cytokinins are mobile phytohormones that regulate plant growth, development, and environmental adaptability. The major cytokinin species include isopentenyl adenine (iP), trans-zeatin (tZ), cis-zeatin (cZ), and dihydrozeatin (DZ). The spatial distributions of different cytokinin species in different organelles, cells, tissues, and organs are primarily shaped by biosynthesis via isopentenyltransferases (IPT), cytochrome P450 monooxygenase, and 5'-ribonucleotide phosphohydrolase and by conjugation or catabolism via glycosyltransferase or cytokinin oxidase/dehydrogenase. Cytokinins bind to histidine receptor kinases in the endoplasmic reticulum or plasma membrane and relay signals to response regulators in the nucleus via shuttle proteins known as histidine phosphotransfer proteins. The movements of cytokinins from sites of biosynthesis to sites of signal perception usually require long-distance, intercellular, and intracellular transport. In the past decade, ATP-binding cassette (ABC) transporters, purine permeases (PUP), AZA-GUANINE RESISTANT (AZG) transporters, equilibrative nucleoside transporters (ENT), and Sugars Will Eventually Be Exported transporters (SWEET) have been characterized as involved in cytokinin transport processes. This review begins by introducing the spatial distributions of various cytokinins and the subcellular localizations of the proteins involved in their metabolism and signaling. Highlights focus on an inventory of the characterized transporters involved in cytokinin compartmentalization, including long-distance, intercellular, and intracellular transport, and the regulation of the spatial distributions of cytokinins by environmental cues. Future directions for cytokinin research are also discussed.

Target-activated multicolor fluorescent dyes for 3D imaging of plasma membranes and tracking of apoptosis.

Real-time tracking of dynamic changes in the three-dimensional morphology of the cell plasma membrane is of great importance for a deeper understanding of physiological processes related to the cell plasma membrane. However, there is a lack of imaging dyes that can specifically be used for a long term labelling of plasma membranes, especially for plant cells. Here, we have used molecular engineering strategies to develop a series of target-activated multicolour fluorescent dyes that can be used for long-term and three-dimensional imaging of plant cell plasma membranes. By combining different electron acceptors and donors, four molecular backbones with different emission colours from green to NIR have been obtained. In the designed styrene-based dyes, referred to as the SD dyes, several functional groups were introduced into the backbones to achieve the properties of target-activated fluorescence, rapid and wash-free staining, high plasma membrane targeting ability and long-term imaging function. Using onion epidermal cells as a platform, these dye molecules can provide high-quality imaging of the plasma membrane for up to 6 hours, providing a powerful tool for long-term monitoring of plasma membrane-related biological events. Calcium-mediated apoptosis of plant cells has been tracked for the first time by monitoring the morphological changes of the plasma membrane in real time using SD dyes. These dyes also exhibit excellent 3D imaging performance of the plasma membrane and were further used to track in real time the 3D morphological changes of the plasma membrane during plasmolysis of plant cells, providing a powerful imaging tool for three-dimensional (3D) biology. This work provides a set of multi-colour dye tools for long-term and three-dimensional imaging of plant cell plasma membranes, and also provides molecular design principles for guiding the transmembrane transport of small molecules.

TPG-functionalized PLGA/PCL nanofiber membrane facilitates periodontal tissue regeneration by modulating macrophages polarization via suppressing PI3K/AKT and NF-κB signaling pathways.

Traditional fibrous membranes employed in guided tissue regeneration (GTR) in the treatment of periodontitis have limitations of bioactive and immunomodulatory properties. We fabricated a novel nTPG/PLGA/PCL fibrous membrane by electrospinning which exhibit excellent hydrophilicity, mechanical properties and biocompatibility. In addition, we investigated its regulatory effect on polarization of macrophages and facilitating the regeneration of periodontal tissue both in vivo and in vitro. These findings showed the 0.5%TPG/PLGA/PCL may inhibit the polarization of RAW 264.7 into M1 phenotype by suppressing the PI3K/AKT and NF-κB signaling pathways. Furthermore, it directly up-regulated the expression of cementoblastic differentiation markers (CEMP-1 and CAP) in periodontal ligament stem cells (hPDLSCs), and indirectly up-regulated the expression of cementoblastic (CEMP-1 and CAP) and osteoblastic (ALP, RUNX2, COL-1, and OCN) differentiation markers by inhibiting the polarization of M1 macrophage. Upon implantation into a periodontal bone defect rats model, histological assessment revealed that the 0.5%TPG/PLGA/PCL membrane could regenerate oriented collagen fibers and structurally intact epithelium. Micro-CT (BV/TV) and the expression of immunohistochemical markers (OCN, RUNX-2, COL-1, and BMP-2) ultimately exhibited satisfactory regeneration of alveolar bone, periodontal ligament. Overall, 0.5%TPG/PLGA/PCL did not only directly promote osteogenic effects on hPDLSCs, but also indirectly facilitated cementoblastic and osteogenic differentiation through its immunomodulatory effects on macrophages. These findings provide a novel perspective for the development of materials for periodontal tissue regeneration.

RETINOBLASTOMA RELATED 1 switches mitosis to meiosis in rice.

The transition from mitosis to meiosis is a critical event in the reproductive development of all sexually reproducing species. However, the mechanisms that regulate this process in plants remain largely unknown. Here, we find that the rice (Oryza sativa L.) protein RETINOBLASTOMA RELATED 1 (RBR1) is essential to the transition from mitosis to meiosis. Loss of RBR1 function results in hyper-proliferative sporogenous-cell-like cells (SCLs) in the anther locules during early stages of reproductive development. These hyper-proliferative SCLs are unable to initiate meiosis, eventually stagnating and degrading at late developmental stages to form pollen-free anthers. These results suggest that RBR1 acts as a gatekeeper of entry into meiosis. Furthermore, cytokinin content is significantly increased in rbr1 mutants, whereas the expression of type-B response factors, particularly LEPTO1, is significantly reduced. Given the known close association of cytokinins with cell proliferation, these findings imply that hyper-proliferative germ cells in the anther locules may be attributed to elevated cytokinin concentrations and disruptions in the cytokinin pathway. Using a genetic strategy, the association between germ cell hyper-proliferation and disturbed cytokinin signaling in rbr1 has been confirmed. In summary, we reveal a unique role of RBR1 in the initiation of meiosis; our results clearly demonstrate that the RBR1 regulatory module is connected to the cytokinin signaling pathway and switches mitosis to meiosis in rice.

Charge-regulated fluorescent anchors enable high-fidelity tracking of plasma membrane dynamics during biological events.

Many biological processes generally require long-term visualization tools for time-scale dynamic changes of the plasma membrane, but there is still a lack of design rules for such imaging tools based on small-molecule fluorescent probes. Herein, we revealed the key regulatory roles of charge number and species of fluorescent dyes in the anchoring ability of the plasma membrane and found that the introduction of multi-charged units and appropriate charge species is often required for fluorescent dyes with strong plasma membrane anchoring ability by systematically investigating the structure-function relationship of cyanostyrylpyridium (CSP) dyes with different charge numbers and species and their imaging performance for the plasma membrane. The CSP-DBO dye constructed exhibits strong plasma membrane anchoring ability in staining the plasma membrane of cells, in addition to many other advantages such as excellent biocompatibility and general universality of cell types. Such a fluorescent anchor has been successfully used to monitor chemically induced plasma membrane damage and dynamically track various cellular biological events such as cell fusion and cytokinesis over a long period of time by continuously monitoring the dynamic morphological changes of the plasma membrane, providing a valuable precise visualization tool to study the physiological response to chemical stimuli and reveal the structural morphological changes and functions of the plasma membrane during these important biological events from a dynamic perspective. Furthermore, CSP-DBO exhibits excellent biocompatibility and imaging capability in vivo such as labelling the plasma membrane in vivo and monitoring the metabolic process of lipofuscin as an aging indicator.

Arabidopsis WRKY1 promotes monocarpic senescence by integrative regulation of flowering, leaf senescence, and nitrogen remobilization.

Monocarpic senescence, characterized by whole-plant senescence following a single flowering phase, is widespread in seed plants, particularly in crops, determining seed harvest time and quality. However, how external and internal signals are systemically integrated into monocarpic senescence remains largely unknown. Here, we report that the Arabidopsis thaliana transcription factor WRKY1 plays essential roles in multiple key steps of monocarpic senescence. WRKY1 expression is induced by age, salicylic acid (SA), and nitrogen (N) deficiency. Flowering and leaf senescence are accelerated in the WRKY1 overexpression lines but are delayed in the wrky1 mutants. The combined DNA affinity purification sequencing and RNA sequencing analyses uncover the direct target genes of WRKY1. Further studies show that WRKY1 coordinately regulates three processes in monocarpic senescence: (1) suppressing FLOWERING LOCUS C gene expression to initiate flowering, (2) inducing SA biosynthesis genes to promote leaf senescence, and (3) activating the N assimilation and transport genes to trigger N remobilization. In summary, our study reveals how one stress-responsive transcription factor, WRKY1, integrates flowering, leaf senescence, and N remobilization processes into monocarpic senescence, providing important insights into plant lifetime regulation.