RESUMO
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.
RESUMO
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.
RESUMO
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.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Flores , Regulação da Expressão Gênica de Plantas , Nitrogênio , Folhas de Planta , Senescência Vegetal , Fatores de Transcrição , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/fisiologia , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Flores/metabolismo , Flores/genética , Flores/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Folhas de Planta/genética , Nitrogênio/metabolismo , Senescência Vegetal/genética , Ácido Salicílico/metabolismoRESUMO
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.
RESUMO
BACKGROUND AND OBJECTIVE: The measurement of portal venous pressure (PVP) has been extensively studied, primarily through indirect methods. However, the potential of ultrasound-guided percutaneous transhepatic PVP measurement as a direct method has been largely unexplored. This study aimed to investigate the accuracy, safety, and feasibility of this approach. METHODS: In vitro, the experiment aimed to select a needle that could accurately transmit pressure, had a small inner diameter and was suitable for liver puncture, and performed on 20 healthy New Zealand white rabbits. An ultrasound-guided percutaneous transhepatic portal vein puncture was undertaken to measure PVP. Additionally, free hepatic venous pressure (FHVP) and wedged hepatic venous pressure (WHVP) were measured under digital subtraction angiography (DSA). The correlation between the two methods was assessed. Enroll study participants from October 18, 2023 to November 11, 2023 with written informed consent. Five patients were measured the PVP under ultrasound guidance before surgery to determine the feasibility of this measurement method. RESULTS: There was no significant difference in the results obtained using 9 different types of needles (P > 0.05). This demonstrated a great repeatability (P < 0.05). The 22G chiba needle with small inner diameter, allowing for accurate pressure transmission and suitable for liver puncture, was utilized for percutaneous transhepatic PVP measurement. There were positive correlations between PVP and HVPG (r = 0.881), PVP and WHVP (r = 0.709), HVPG and WHVP (r = 0.729), IVCP and FHVP (r = 0.572). The PVP was accurately and safely measured in 5 patients with segmental hepatectomy. No complications could be identified during postoperative ultrasound. CONCLUSION: Percutaneous transhepatic portal venous puncture under ultrasound guidance is accurate, safe and feasible to measure portal venous pressure. CLINICAL TRIAL REGISTRATION NUMBER: This study has been registered in the Chinese Clinical Trial Registry with registration number ChiCTR2300076751.
Assuntos
Estudos de Viabilidade , Pressão na Veia Porta , Veia Porta , Animais , Coelhos , Humanos , Masculino , Feminino , Veia Porta/diagnóstico por imagem , Pessoa de Meia-Idade , Ultrassonografia de Intervenção/métodos , Adulto , Fígado/diagnóstico por imagem , Fígado/cirurgia , Fígado/irrigação sanguínea , Punções/métodos , Ultrassonografia/métodos , Idoso , Angiografia Digital/métodos , Determinação da Pressão Arterial/métodosRESUMO
Membranes with precise Li+/Na+ and Li+/K+ separations are imperative for lithium extraction from brine to address the lithium supply shortage. However, achieving this goal remains a daunting challenge due to the similar valence, chemical properties, and subtle atomic-scale distinctions among these monovalent cations. Herein, inspired by the strict size-sieving effect of biological ion channels, a membrane is presented based on nonporous crystalline materials featuring structurally rigid, dimensionally confined, and long-range ordered ion channels that exclusively permeate naked Li+ but block Na+ and K+. This naked-Li+-sieving behavior not only enables unprecedented Li+/Na+ and Li+/K+ selectivities up to 2707.4 and 5109.8, respectively, even surpassing the state-of-the-art membranes by at least two orders of magnitude, but also demonstrates impressive Li+/Mg2+ and Li+/Ca2+ separation capabilities. Moreover, this bioinspired membrane has to be utilized for creating a one-step lithium extraction strategy from natural brines rich in Na+, K+, and Mg2+ without utilizing chemicals or creating solid waste, and it simultaneously produces hydrogen. This research has proposed a new type of ion-sieving membrane and also provides an envisioning of the design paradigm and development of advanced membranes, ion separation, and lithium extraction.
RESUMO
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 â¼4.5 times and â¼7.0 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.
RESUMO
To evaluate the effects of varying proportions of yak meat in feed on the growth of rats and provide a theoretical basis for selecting the optimal feed proportion suitable for rats. This study was designed as a one-variable experiment. Fifty male rats were divided into five groups. The ratios of yak meat to basal feed of rats in four dietary treatment groups were 2:8, 4:6, 6:4, and 8:2, respectively, while those in the control group were only provided a basal diet. In the feeding experiment, the body weights of the rats were recorded on Day 0 and subsequently in the first, second, third, and fourth weeks, along with quantities of feed intake. The body and tail lengths, as well as the waist circumference of the rats, were measured, and blood samples were collected in the fourth week for routine blood and biochemistry investigations. The rats in the 4:6 feed group had the best body condition. They had normal body and tail lengths, smaller waist circumferences, good posture, and were in better overall health than rats in the other groups. The results indicate that the 4:6 diet was optimal for enhancing rats' growth performance compared to the other diets.
RESUMO
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.
Assuntos
Degradação Associada com o Retículo Endoplasmático , Proteínas de Plantas , Ubiquitina-Proteína Ligases , Zea mays , Zea mays/genética , Zea mays/metabolismo , Zea mays/crescimento & desenvolvimento , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Retículo Endoplasmático/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Animais , Regulação da Expressão Gênica de Plantas , Estresse do Retículo Endoplasmático , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Camundongos , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Folhas de Planta/metabolismo , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Resposta a Proteínas não DobradasRESUMO
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.
RESUMO
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.
Assuntos
Citocininas , Transdução de Sinais , Citocininas/metabolismo , Transporte Biológico , Plantas/metabolismo , Reguladores de Crescimento de Plantas/metabolismoRESUMO
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.
RESUMO
Long-term visualization of changes in plasma membrane dynamics during important physiological processes can provide intuitive and reliable information in a 4D mode. However, molecular tools that can visualize plasma membranes over extended periods are lacking due to the absence of effective design rules that can specifically track plasma membrane fluorescent dye molecules over time. Using plant plasma membranes as a model, we systematically investigated the effects of different alkyl chain lengths of FMR dye molecules on their performance in imaging plasma membranes. Our findings indicate that alkyl chain length can effectively regulate the permeability of dye molecules across plasma membranes. The study confirms that introducing medium-length alkyl chains improves the ability of dye molecules to target and anchor to plasma membranes, allowing for long-term imaging of plasma membranes. This provides useful design rules for creating dye molecules that enable long-term visualization of plasma membranes. Using the amphiphilic amino-styryl-pyridine fluorescent skeleton, we discovered that the inclusion of short alkyl chains facilitated rapid crossing of the plasma membrane by the dye molecules, resulting in staining of the cell nucleus and indicating improved cell permeability. Conversely, the inclusion of long alkyl chains hindered the crossing of the cell wall by the dye molecules, preventing staining of the cell membrane and demonstrating membrane impermeability to plant cells. The FMR dyes with medium-length alkyl chains rapidly crossed the cell wall, uniformly stained the cell membrane, and anchored to it for a long period without being transmembrane. This allowed for visualization and tracking of the morphological dynamics of the cell plasma membrane during water loss in a 4D mode. This suggests that the introduction of medium-length alkyl chains into amphiphilic fluorescent dyes can transform them from membrane-permeable fluorescent dyes to membrane-staining fluorescent dyes suitable for long-term imaging of the plasma membrane. In addition, we have successfully converted a membrane-impermeable fluorescent dye molecule into a membrane-staining fluorescent dye by introducing medium-length alkyl chains into the molecule. This molecular engineering of dye molecules with alkyl chains to regulate cell permeability provides a simple and effective design rule for long-term visualization of the plasma membrane, and a convenient and feasible means of chemical modification for efficient transmembrane transport of small molecule drugs.
Assuntos
Permeabilidade da Membrana Celular , Membrana Celular , Corantes Fluorescentes , Corantes Fluorescentes/química , Membrana Celular/metabolismo , Membrana Celular/química , Arabidopsis/química , Arabidopsis/metabolismoRESUMO
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.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Regulação da Expressão Gênica de Plantas , Lactonas , Folhas de Planta , Senescência Vegetal , Fatores de Transcrição , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/efeitos dos fármacos , Folhas de Planta/metabolismo , Folhas de Planta/efeitos dos fármacos , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Lactonas/metabolismo , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Ácido Salicílico/metabolismo , Salicilatos/metabolismo , Transdução de Sinais , Ligação Proteica/efeitos dos fármacos , Proteólise/efeitos dos fármacos , Vias Biossintéticas/efeitos dos fármacos , Vias Biossintéticas/genéticaRESUMO
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.
RESUMO
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.
Assuntos
Meiose , Mitose , Oryza , Proteínas de Plantas , Oryza/genética , Oryza/metabolismo , Meiose/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas , Citocininas/metabolismoRESUMO
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.
Assuntos
Ácido Abscísico , Reguladores de Crescimento de Plantas , Reguladores de Crescimento de Plantas/metabolismo , Ácido Abscísico/metabolismo , Citocininas/metabolismo , Plantas/metabolismo , Hormônios , LipídeosRESUMO
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.
RESUMO
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.