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1.
J Biol Chem ; 299(12): 105481, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38041932

RESUMEN

Singlet oxygen (1O2) has a very short half-life of 10-5 s; however, it is a strong oxidant that causes growth arrest and necrotic lesions on plants. Its signaling pathway remains largely unknown. The Arabidopsis flu (fluorescent) mutant accumulates a high level of 1O2 and shows drastic changes in nuclear gene expression. Only two plastid proteins, EX1 (executer 1) and EX2 (executer 2), have been identified in the singlet oxygen signaling. Here, we found that the transcription factor abscisic acid insensitive 4 (ABI4) binds the promoters of genes responsive to 1O2-signals. Inactivation of the ABI4 protein in the flu/abi4 double mutant was sufficient to compromise the changes of almost all 1O2-responsive-genes and rescued the lethal phenotype of flu grown under light/dark cycles, similar to the flu/ex1/ex2 triple mutant. In addition to cell death, we reported for the first time that 1O2 also induces cell wall thickening and stomatal development defect. Contrastingly, no apparent growth arrest was observed for the flu mutant under normal light/dim light cycles, but the cell wall thickening (doubled) and stomatal density reduction (by two-thirds) still occurred. These results offer a new idea for breeding stress tolerant plants.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Ácido Abscísico/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Pared Celular/metabolismo , Regulación de la Expresión Génica de las Plantas , Luz , Oxígeno Singlete/metabolismo , Transcriptoma , Estomas de Plantas/metabolismo
2.
Nat Commun ; 14(1): 6262, 2023 10 07.
Artículo en Inglés | MEDLINE | ID: mdl-37805547

RESUMEN

Plant height is a key agronomic trait that affects yield and is controlled by both phytohormone gibberellin (GA) and ultraviolet-B (UV-B) irradiation. However, whether and how plant height is modulated by UV-B-mediated changes in GA metabolism are not well understood. It has not been reported that the E3 ubiquitin ligase Anaphase Promoting Complex/Cyclosome (APC/C) is involved in the regulation of plant growth in response to environmental factors. We perform a forward genetic screen in soybean and find that a mutation in Glycine max Increased Leaf Petiole Angle1 (GmILPA1), encoding a subunit of the APC/C, lead to dwarfism under UV-B irradiation. UV-B promotes the accumulation of GmILPA1, which ubiquitinate the GA catabolic enzyme GA2 OXIDASE-like (GmGA2ox-like), resulting in its degradation in a UV-B-dependent manner. Another E3 ligase, GmUBL1, also ubiquitinate GmGA2ox-like and enhance the GmILPA1-mediated degradation of GmGA2ox-like, which suggest that GmILPA1-GmGA2ox-like module counteract the UV-B-mediated reduction of bioactive GAs. We also determine that GmILPA1 is a target of selection during soybean domestication and breeding. The deletion (Indel-665) in the promoter might facilitate the adaptation of soybean to high UV-B irradiation. This study indicates that an evolutionary GmILPA1 variant has the capability to develop ideal plant architecture with soybean cultivars.


Asunto(s)
Glycine max , Ubiquitina-Proteína Ligasas , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo , Glycine max/genética , Glycine max/metabolismo , Giberelinas , Fitomejoramiento , Ciclosoma-Complejo Promotor de la Anafase , Plantas/metabolismo , Hojas de la Planta/metabolismo
3.
Plant Cell ; 36(1): 112-135, 2023 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-37770034

RESUMEN

Reactive oxygen species (ROS) play an essential role in plant growth and responses to environmental stresses. Plant cells sense and transduce ROS signaling directly via hydrogen peroxide (H2O2)-mediated posttranslational modifications (PTMs) on protein cysteine residues. Here, we show that the H2O2-mediated cysteine oxidation of NAC WITH TRANS-MEMBRANE MOTIF1-LIKE 1 (GmNTL1) in soybean (Glycine max) during salt stress promotes its release from the endoplasmic reticulum (ER) membrane and translocation to the nucleus. We further show that an oxidative posttranslational modification on GmNTL1 residue Cys-247 steers downstream amplification of ROS production by binding to and activating the promoters of RESPIRATORY BURST OXIDASE HOMOLOG B (GmRbohB) genes, thereby creating a feed-forward loop to fine-tune GmNTL1 activity. In addition, oxidation of GmNTL1 Cys-247 directly promotes the expression of CATION H+ EXCHANGER 1 (GmCHX1)/SALT TOLERANCE-ASSOCIATED GENE ON CHROMOSOME 3 (GmSALT3) and Na+/H+ Antiporter 1 (GmNHX1). Accordingly, transgenic overexpression of GmNTL1 in soybean increases the H2O2 levels and K+/Na+ ratio in the cell, promotes salt tolerance, and increases yield under salt stress, while an RNA interference-mediated knockdown of GmNTL1 elicits the opposite effects. Our results reveal that the salt-induced oxidation of GmNTL1 promotes its relocation and transcriptional activity through an H2O2-mediated posttranslational modification on cysteine that improves resilience of soybean against salt stress.


Asunto(s)
Glycine max , Tolerancia a la Sal , Glycine max/genética , Tolerancia a la Sal/genética , Peróxido de Hidrógeno/metabolismo , Factores de Transcripción/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Cisteína/metabolismo , Estrés Fisiológico/genética , Plantas Modificadas Genéticamente/metabolismo , Regulación de la Expresión Génica de las Plantas
4.
Front Public Health ; 11: 1164744, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37124786

RESUMEN

Background: Despite years of public cardiopulmonary resuscitation (CPR) training efforts, the training rate and survival following out-of-hospital cardiac arrest (OHCA) have increased modestly in China. Access is imperative to increase the public CPR training rate, which is determined by both demand- (e.g., the lay public) and supply-side (e.g., CPR trainers) factors. We aimed to explore the demand and supply determinants of access to CPR training for the lay public in China. Methods: Qualitative semi-structured interviews were conducted with 77 laypeople (demand side) and eight key stakeholders from CPR training institutions (supply side) in Shanghai, China. The interview guide was informed by Levesque et al. healthcare access framework. Data were transcribed, quantified, described, and analyzed through thematic content analysis. Results: On the demand side, the laypeople's ability to perceive their need and willingness for CPR training was strong. However, they failed to access CPR training mainly due to the lack of information on where to get trained. Overestimation of skills, optimism bias, and misconceptions impeded laypeople from attending training. On the supply side, trainers were able to meet the needs of the trainees with existing resources, but they relied on participants who actively sought out and registered for training and lacked an understanding of the needs of the public for marketing and encouraging participation in the training. Conclusion: Insufficient information and lack of initiative on the demand side, lack of motivation, and understanding of public needs on the supply side all contributed to the persistently low CPR training rate in China. Suppliers should integrate resources, take the initiative to increase the CPR training rate, innovate training modes, expand correct publicity, and establish whole-process management of training programs.


Asunto(s)
Reanimación Cardiopulmonar , Paro Cardíaco Extrahospitalario , Humanos , Reanimación Cardiopulmonar/educación , China , Paro Cardíaco Extrahospitalario/terapia
5.
Adv Mater ; 35(37): e2203684, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35735048

RESUMEN

Diverse microscopic ionic dynamics help mediate the ability of a biological neural network to handle complex tasks with low energy consumption. Thus, rich internal ionic dynamics in memristors based on transition metal oxide are expected to provide a unique and useful platform for implementing energy-efficient neuromorphic computing. To this end, a titanium oxide (TiOx )-based interface-type dynamic memristor and an niobium oxide (NbOx )-based Mott memristor are integrated as an artificial dendrite and spike-firing soma, respectively, to construct a dendritic neuron unit for realizing high-efficiency spatial-temporal information processing. Further, a dendritic neural network is hardware-implemented for spatial-temporal information processing to highlight the computational advantages achieved by incorporating dendritic functions in the network. Human motion recognition is demonstrated using the Nanyang Technological University-Red Green Blue (NTU-RGB) dataset as a benchmark spatial-temporal task; it shows a nearly 20% improvement in accuracy for the memristors-based hardware incorporating dendrites and a 1000× advantage in power efficiency compared to that of the graphics processing unit (GPU). The dendritic neuron developed in this study can be considered a critical building block for implementing more bio-plausible neural networks that can manage complex spatial-temporal tasks with high efficiency.

6.
Front Psychol ; 14: 1291711, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38259527

RESUMEN

Objectives: Parents are one of the main social agents that shape young athletes' experiences and participation in sports, but they are also the least explored group in the literature. Therefore, the purpose of this study was to conduct a systematic review of research on the role of parents in the motivation of young athletes. Method: The systematic literature review consisted of four electronic databases from which 29 articles published in English and in full-text form in peer-reviewed journals between 1999 and 2023 were retrieved. Results: A total of 29 studies met the eligibility criteria. These studies collectively surveyed 9,185 young athlete participants and 2,191 parent participants. The sample comprised 26 quantitative studies and 3 qualitative studies. The findings underscore that parents play both unique and synergistic multidimensional roles in motivating young athletes. Parents' positive goals and values, autonomy-supportive parenting styles, moderate parental involvement, positive parent-child relationships, and a parent-initiated task climate are identified as optimal parenting strategies. Conclusion: While parents undeniably play a crucial role in motivating young athletes, the manner and extent of their involvement are key.

7.
Adv Mater ; 34(42): e2205926, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36027579

RESUMEN

Efficient exciton diffusion and charge transport play a vital role in advancing the power conversion efficiency (PCE) of organic solar cells (OSCs). Here, a facile strategy is presented to simultaneously enhance exciton/charge transport of the widely studied PM6:Y6-based OSCs by employing highly emissive trans-bis(dimesitylboron)stilbene (BBS) as a solid additive. BBS transforms the emissive sites from a more H-type aggregate into a more J-type aggregate, which benefits the resonance energy transfer for PM6 exciton diffusion and energy transfer from PM6 to Y6. Transient gated photoluminescence spectroscopy measurements indicate that addition of BBS improves the exciton diffusion coefficient of PM6 and the dissociation of PM6 excitons in the PM6:Y6:BBS film. Transient absorption spectroscopy measurements confirm faster charge generation in PM6:Y6:BBS. Moreover, BBS helps improve Y6 crystallization, and current-sensing atomic force microscopy characterization reveals an improved charge-carrier diffusion length in PM6:Y6:BBS. Owing to the enhanced exciton diffusion, exciton dissociation, charge generation, and charge transport, as well as reduced charge recombination and energy loss, a higher PCE of 17.6% with simultaneously improved open-circuit voltage, short-circuit current density, and fill factor is achieved for the PM6:Y6:BBS devices compared to the devices without BBS (16.2%).

8.
J Agric Food Chem ; 69(44): 13135-13142, 2021 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-34709805

RESUMEN

α-Santalene belongs to a class of natural compounds with many physiological functions and medical applications. Advances in metabolic engineering enable non-native hosts (e.g., Escherichia coli) to produce α-santalene, the precursor of sandalwood oil. However, imbalances in enzymatic activity often result in a metabolic burden on hosts and repress the synthetic capacity of the desired product. In this work, we manipulated ribosome binding sites (RBSs) to optimize an α-santalene synthetic operon in E. coli, and the best engineered E. coli NA-IS3D strain could produce α-santalene at a titer of 412 mg·L-1. Concerning the observation of the inverse correlation between indole synthesis and α-santalene production, this study speculated that indole-associated amino acid metabolism would be competitive to the synthesis of α-santalene rather than indole toxicity itself. The deletion of tnaA could lead to a 1.5-fold increase in α-santalene production to a titer of 599 mg·L-1 in E. coli tnaA- NA-IS3D. Our results suggested that the optimization of RBS sets of the synthetic module and attenuation of the competitive pathway are promising approaches for improving the production of terpenoids including α-santalene.


Asunto(s)
Escherichia coli , Ingeniería Metabólica , Escherichia coli/genética , Aceites de Plantas , Sesquiterpenos Policíclicos , Sesquiterpenos
9.
Front Plant Sci ; 12: 794020, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-35154184

RESUMEN

Soil stress, such as salinity, is a primary cause of global crop yield reduction. Existing crop phenotyping platforms cannot fully meet the specific needs of phenomics studies of plant response to soil stress in terms of throughput, environmental controllability, or root phenotypic acquisition. Here, we report the WinRoots, a low-cost and high-throughput plant soil cultivation and phenotyping system that can provide uniform, controlled soil stress conditions and accurately quantify the whole-plant phenome, including roots. Using soybean seedlings exposed to salt stress as an example, we demonstrate the uniformity and controllability of the soil environment in this system. A high-throughput multiple-phenotypic assay among 178 soybean cultivars reveals that the cotyledon character can serve as a non-destructive indicator of the whole-seedling salt tolerance. Our results demonstrate that WinRoots is an effective tool for high-throughput plant cultivation and soil stress phenomics studies.

10.
Int J Mol Sci ; 21(19)2020 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-33050099

RESUMEN

Nitrogen (N), phosphorus (P), and potassium (K) are three essential macro-elements for plant growth and development. Used to improve yield in agricultural production, the excessive use of chemical fertilizers often leads to increased production costs and ecological environmental pollution. Vitamins C and E are antioxidants that play an important role in alleviating abiotic stress. However, there are few studies on alleviating oxidative stress caused by macro-element deficiency. Here, we used Arabidopsis vitamin E synthesis-deficient mutant vte4 and vitamin C synthesis-deficient mutant vtc1 on which exogenous vitamin E and vitamin C, respectively, were applied at the bolting stage. In the deficiency of macro-elements, the Arabidopsis chlorophyll content decreased, malondialdehyde (MDA) content and relative electric conductivity increased, and reactive oxygen species (ROS) accumulated. The mutants vtc1 and vte4 are more severely stressed than the wild-type plants. Adding exogenous vitamin E was found to better alleviate stress than adding vitamin C. Vitamin C barely affected and vitamin E significantly inhibited the synthesis of ethylene (ETH) and jasmonic acid (JA) genes, thereby reducing the accumulation of ETH and JA that alleviated the senescence caused by macro-element deficiency at the later stage of bolting in Arabidopsis. A deficiency of macro-elements also reduced the yield and germination rate of the seeds, which were more apparent in vtc1 and vte4, and adding exogenous vitamin C and vitamin E, respectively, could restore them. This study reported, for the first time, that vitamin E is better than vitamin C in delaying seedling senescence caused by macro-element deficiency in Arabidopsis.


Asunto(s)
Antioxidantes/farmacología , Arabidopsis/efectos de los fármacos , Arabidopsis/genética , Ácido Ascórbico/farmacología , Resistencia a la Enfermedad/efectos de los fármacos , Plantones/efectos de los fármacos , Vitamina E/farmacología , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Clorofila/metabolismo , Ciclopentanos/antagonistas & inhibidores , Ciclopentanos/metabolismo , Etilenos/antagonistas & inhibidores , Etilenos/metabolismo , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Malondialdehído/metabolismo , Estrés Oxidativo/efectos de los fármacos , Oxilipinas/antagonistas & inhibidores , Oxilipinas/metabolismo , Enfermedades de las Plantas/prevención & control , Hojas de la Planta/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Plantones/genética , Plantones/metabolismo , Semillas/metabolismo , Transducción de Señal/efectos de los fármacos , Factores de Tiempo
11.
Sci Total Environ ; 740: 139911, 2020 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-32927563

RESUMEN

Dissolved humic substances (DHS) are ubiquitous in surface and subsurface aquatic environments and greatly affect the redox transformation of organic contaminants as reactants and/or electron transfer mediators. However, little is known about the quantitative relationship between the mediation efficiency of DHS and the physicochemical properties of DHS. Using sulfide-induced nitrobenzene reduction as a model system, we measured the reduction rate of nitrobenzene in the presence of 12 different DHS (20 mgC·L-1), including 4 commercial humic substances (Suwannee River humic and fulvic acids and Pahokee Peat humic and fulvic acids) and 8 soil humic substances collected as leachates from a wide variety of soils. In addition to the UV-vis absorption and fluorescence spectra, the electron donating/accepting capacities (EDC/EAC) of the tested DHS were measured using an electrochemical approach. A significant linear correlation (r = 0.99, P < .0001) was observed between the observed pseudo-first-order rate constant (kobs) of nitrobenzene reduction and the sum of EDC and EAC which is defined as electron transfer capacity (ETC) of DHS. A relatively good positive correlation (r = 0.69, P < .2) was shown between the kobs and the specific UV-absorbance at 254 nm (SUVA254), whereas no good correlation was shown between the kobs and the fluorescence of the C1-C4 components identified by the excitation emission matrices and parallel factor (EEM-PARAFAC) analysis. This study provides a new framework for accurate prediction of the capability of DHS in mediating the redox transformation of organic contaminants. CAPSULE: A significant linear correlation exists between the kinetics of nitrobenzene reduction by sulfide and electron transfer capacity of mediating dissolved humic substances.

12.
Biotechnol Bioeng ; 117(11): 3499-3507, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32691870

RESUMEN

Squalene is a lipophilic and non-volatile triterpene with many industrial applications for food, pharmaceuticals, and cosmetics. Metabolic engineering focused on optimization of the production pathway suffer from little success in improving titers because of a limited space of the cell membrane accommodating the lipophilic product. Extension of cell membrane would be a promising approach to overcome the storage limitation for successful production of squalene. In this study, Escherichia coli was engineered for squalene production by overexpression of some membrane proteins. The highest production of 612 mg/L was observed in the engineered E. coli with overexpression of Tsr, a serine chemoreceptor protein, which induced invagination of inner membrane to form multilayered structure. It was also observed an increase in unsaturated fatty acid in membrane lipids composition, suggesting cellular response to maintain membrane fluidity against squalene accumulation in the engineered strain. This study potentiates the capability of E. coli for squalene production and provides an effective strategy for the enhanced production of such compounds.


Asunto(s)
Membrana Celular , Escherichia coli , Ingeniería Metabólica/métodos , Escualeno/metabolismo , Membrana Celular/química , Membrana Celular/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas Quimiotácticas Aceptoras de Metilo/genética , Proteínas Quimiotácticas Aceptoras de Metilo/metabolismo , Ácido Mevalónico/metabolismo
13.
Plant Sci ; 293: 110323, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32081254

RESUMEN

Plant somatic cells can be reprogrammed during in vitro culture. Callus induction is the initial step of a typical plant regeneration system. Recent studies showed that auxin-induced callus formation in multiple organs occurs from the pericycle or pericycle-like cells via a root developmental pathway. However, the molecular control of callus formation is largely unknown. Here, two MYB transcription factors, MYB94 and MYB96, were shown to play negative roles in auxin-induced callus formation in Arabidopsis. MYB94 and MYB96 were expressed in the newly formed callus. myb96, myb94, and myb94 myb96 generated more calli than the WT, with myb94 myb96 producing the most. MYB94 and MYB96 repressed expression of LATERAL ORGAN BOUNDARIES-DOMAIN 29 (LBD29) via directly binding to the gene's promoter. The loss of function of LBD29 partly rescued the callus formation defect of myb94 myb96. Our findings found MYB94 and MYB96 to be important repressors of callus formation and MYB94/96-LBD29 as a new regulatory pathway acting in parallel with ARF7/19-LBDs' pathway to modulate in vitro callus formation.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Transactivadores/metabolismo , Factores de Transcripción/metabolismo , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Proteínas de Arabidopsis/genética , Callo Óseo/crecimiento & desarrollo , Sistemas CRISPR-Cas , Regulación de la Expresión Génica de las Plantas , Ácidos Indolacéticos/metabolismo , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Plantas Modificadas Genéticamente , Regiones Promotoras Genéticas , Transactivadores/genética , Transcriptoma
14.
Plant Sci ; 291: 110326, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31928665

RESUMEN

Transcription factor activation and DNA methylation are important plant responses to abiotic stress. Here, we established that the salinity stress-induced expression of the soybean (Glycine max) transcription factor-encoding gene GmMYB84 relies on DNA methylation. The level of DNA methylation at sequences 690 nt to 950 nt upstream of the GmMYB84 transcription initiation codon was markedly reduced in plants exposed to salinity stress, resulting in a higher abundance of transcripts. When challenged with salinity stress, plants constitutively expressing GmMYB84 outperformed untransformed plants with respect to their germination rate, primary root elongation, proline accumulation, antioxidant enzyme activity, membrane integrity, and K+ levels. Arabidopsis thaliana plants heterologously expressing GmMYB84 were more tolerant to salt stress and exhibited higher germination rates than the wild type. Electrophoretic mobility shift assays revealed that GmMYB84 binds to the cis-regulatory sequences of GmAKT1, the homolog of ARABIDOPSIS K+ TRANSPORTER 1 (AKT1). Thus, DNA methylation modulates the salinity stress-induced expression of the soybean transcription factor-encoding gene GmMYB84 and thereby confers salinity stress tolerance.


Asunto(s)
Regulación de la Expresión Génica de las Plantas/fisiología , Glycine max/fisiología , Proteínas de Plantas/genética , Tolerancia a la Sal/genética , Factores de Transcripción/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismo , Glycine max/genética , Factores de Transcripción/metabolismo
15.
Sci Total Environ ; 673: 29-35, 2019 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-30981921

RESUMEN

Although dissolved black carbon (DBC) is an important component of dissolved organic matter (DOM), little is known about the electron transfer properties of DBC and their correlation with the structural properties. This study determined the electron donating/accepting capacities (EDC/EAC) of six DBC collected from water extracts of black carbon derived by pyrolyzing crop residues (soybean, wheat, rice, sorghum, peanut, and corn) using an electrochemical approach, along with their chemical and spectroscopic properties. The EDC of the tested DBC ranged from 2.42 to 7.10 mmole-(gC)-1and was generally much higher than the EDC (1.31-3.78 mmole-(gC)-1) of the four standard dissolved humic substances (DHS). In contrast, with the exception of the sorghum DBC, the EAC of all DBC (0.40-0.81 mmole-(gC)-1) was apparently lower than the EAC of DHS (0.87-1.68 mmole-(gC)-1). For the whole pool of DBC and DHS, a strong positive correlation (r = 0.94, P < 0.05) existed between the EDC and the phenolic group content quantified by base titration, suggesting that phenolic groups were the major electron-donating groups. The EAC and EDC of the tested DOM pool were further correlated with the components identified from the fluorescence excitation emission matrices and parallel factor (EEM-PARAFAC) analysis. This is the first study to show that DBC has significantly different electron transfer properties from humic substances and thus likely behaviors differently in many geochemical and environmental aspects. Capsule: Dissolved black carbon (DBC) has significantly different electron-donating/accepting capacities (EDC/EAC) from humic substances.


Asunto(s)
Sustancias Húmicas , Modelos Químicos , Hollín , Transporte de Electrón , Electrones
16.
Nitric Oxide ; 76: 6-15, 2018 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-29510200

RESUMEN

Nitric oxide (NO) has a general inhibitory effects on chlorophyll biosynthesis, especially to the step of 5-aminolevulinic acid (ALA) biosynthesis and protochlorophyllide (Pchlide) to chlorophyllide (Chlide) conversion (responsible by the NADPH:Pchlide oxidoreductase POR). Previous study suggested that barley large POR aggregates may be generated by dithiol oxidation of cysteines of two POR monomers, which can be disconnected by some reducing agents. POR aggregate assembly may be correlated with seedling greening in barley, but not in Arabidopsis. Thus, NO may affect POR activity and seedling greening differently between Arabidopsis and barley. We proved this assumption by non-denaturing gel-analysis and reactive oxygen species (ROS) monitoring during the greening. NO treatments cause S-nitrosylation to POR cysteine residues and disassembly of POR aggregates. This modification reduces POR activity and induces Pchlide accumulation and singlet oxygen generation upon dark-to-high-light shift (and therefore inducing photobleaching lesions) in barley leaf apex, but not in Arabidopsis seedlings. ROS staining and ROS-related-gene expression detection confirmed that superoxide anion and singlet oxygen accumulated in barley etiolated seedlings after the NO treatments, when exposed to a fluctuating light. The data suggest that POR aggregate assembly may be correlated with barley chlorophyll biosynthesis and redox homeostasis during greening. Cysteine S-nitrosylation may be one of the key reasons for the NO-induced inhibition to chlorophyll biosynthetic enzymes.


Asunto(s)
Arabidopsis/metabolismo , Clorofilidas/biosíntesis , Hordeum/metabolismo , Óxido Nítrico/metabolismo , Oxígeno Singlete/metabolismo
17.
BMJ Open ; 7(5): e014932, 2017 05 25.
Artículo en Inglés | MEDLINE | ID: mdl-28550021

RESUMEN

OBJECTIVES: Many clinical studies have indicated that obstructive sleep apnoea (OSA), the most common chronic sleep disorder, may affect neurocognitive function, and that treatment for continuous positive airway pressure (CPAP) has some neurocognitive protective effects against the adverse effects of OSA. However, the effects of CPAP treatment on neurocognitive architecture and function remain unclear. Therefore, this multicentre trial was designed to investigate whether and when neurocognitive architecture and function in patients with OSA can be improved by CPAP treatment and to explore the role of gut microbiota in improving neurocognitive function during treatment. METHODS/DESIGN: This study will be a multicentre, randomised, controlled trial with allocation concealment and assessor blinding. A total of 148 eligible patients with moderate to severe OSA will be enrolled from five sleep centres and randomised to receive CPAP with best supportive care (BSC) intervention or BSC intervention alone. Cognitive function, structure and function of brain regions, gut microbiota, metabolites, biochemical variables, electrocardiography, echocardiography, pulmonary function and arterial stiffness will be assessed at baseline before randomisation and at 3, 6 and 12 months. ETHICS AND DISSEMINATION: This study has been approved by the Medical Ethics Committee of Shanghai Jiao Tong University Affiliated Sixth People's Hospital (approval number 2015-79). The results from this study will be published in peer-reviewed journals and at relevant conferences. TRIAL REGISTRATION NUMBER: NCT02886156; pre-results.


Asunto(s)
Cognición/fisiología , Disfunción Cognitiva/fisiopatología , Presión de las Vías Aéreas Positiva Contínua , Sistema Hipotálamo-Hipofisario/fisiopatología , Sistema Hipófiso-Suprarrenal/fisiopatología , Apnea Obstructiva del Sueño/terapia , Adulto , China , Disfunción Cognitiva/etiología , Disfunción Cognitiva/terapia , Electrocardiografía , Femenino , Estudios de Seguimiento , Neuroimagen Funcional , Microbioma Gastrointestinal/fisiología , Humanos , Masculino , Persona de Mediana Edad , Selección de Paciente , Estudios Prospectivos , Apnea Obstructiva del Sueño/complicaciones , Apnea Obstructiva del Sueño/fisiopatología , Factores de Tiempo , Resultado del Tratamiento
18.
Transgenic Res ; 25(4): 507-16, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-26951193

RESUMEN

Bombyxin (BBX) is an insulin-like peptide exists in the silkworm Bombyx mori. Our previous studies on the effects of inhibiting BBX-B8 expression found that BBX-B8 is important for the development of organ, reproduction and trehalose metabolism in the silkworms. In this paper, we investigated the expression profile of the BBX-B8 gene and effect of BBX-B8 overexpression on the development, body weight, silk protein synthesis and egg diapause of B. mori to further understand BBX-B8 functions. BBX-B8 gene expression could be detected in the brains, midguts, anterior silkglands, ovaries, testes, fat bodies, hemolymph, malpighian tubules and embryos by RT-PCR, however it was mainly expressed in the brain. Western blots showed that the change in BBX-B8 expression was not obvious in the brain of 1- to 4-day-old larvae of fifth instar silkworms, but expression increased substantially at 5- to 6-day-old larvae of fifth instar silkworms. Transgenic silkworms overexpressing BBX-B8 were obtained by introducing non-transposon transgenic vector pIZT-B8 containing a BBX-B8 gene driven by Orgyia pseudotsugata nucleopolyhedrovirus IE2 promoter into the genome. Development duration of the transgenic silkworms was delayed by 2.5-3.5 days. Cocoon shell weight of transgenic silkworms was reduced by 4.79 % in females and 7.44 % in males, pupal weight of transgenic silkworms was reduced 6.75 % in females and 13.83 % in males compared to non-transgenic silkworms, and 5.56-14.29 % of transgenic moths laid nondiapausing eggs. All results indicated that BBX-B8 plays an important role in the development, silk protein synthesis and egg diapause of silkworm.


Asunto(s)
Animales Modificados Genéticamente/genética , Bombyx/crecimiento & desarrollo , Diapausa/genética , Neuropéptidos/genética , Seda/biosíntesis , Animales , Peso Corporal/genética , Bombyx/genética , Bombyx/fisiología , Femenino , Regulación del Desarrollo de la Expresión Génica , Larva , Masculino , Regiones Promotoras Genéticas , Seda/genética
19.
Org Lett ; 16(19): 5156-9, 2014 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-25222652

RESUMEN

A novel and efficient method for the benzannulation of indoles to carbazoles is reported. γ-Carbonyl tert-butylperoxide is applied as a new diene building block for the π-extension of simple indoles. The synthetic utility of this method is demonstrated by concise and selective total syntheses of naturally occurring carbazole alkaloids, olivacine, and asteropusazole A.


Asunto(s)
Alcaloides/síntesis química , Carbazoles/síntesis química , Elipticinas/síntesis química , Indoles/química , Alcaloides/química , Carbazoles/química , Elipticinas/química , Estructura Molecular , Estereoisomerismo
20.
Org Lett ; 15(21): 5432-5, 2013 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-24117331

RESUMEN

The Brønsted acid catalyzed rearrangement of tert-butyl peroxides provides a new strategy to construct 2,3-disubstituted furans via 1,2-aryl migration. In addition, tert-butyl peroxides could also be transformed into 2,3,5-trisubstituted or 2,5-disubstituted furans through a sequence of base-catalyzed Kornblum-DelaMare rearrangements and acid-promoted Paal-Knorr reactions.

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