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1.
Plant Cell ; 35(7): 2527-2551, 2023 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-36976907

RESUMO

Fungi and oomycetes deliver effectors into living plant cells to suppress defenses and control plant processes needed for infection. Little is known about the mechanism by which these pathogens translocate effector proteins across the plasma membrane into the plant cytoplasm. The blast fungus Magnaporthe oryzae secretes cytoplasmic effectors into a specialized biotrophic interfacial complex (BIC) before translocation. Here, we show that cytoplasmic effectors within BICs are packaged into punctate membranous effector compartments that are occasionally observed in the host cytoplasm. Live cell imaging with fluorescently labeled proteins in rice (Oryza sativa) showed that these effector puncta colocalize with the plant plasma membrane and with CLATHRIN LIGHT CHAIN 1, a component of clathrin-mediated endocytosis (CME). Inhibiting CME using virus-induced gene silencing and chemical treatments resulted in cytoplasmic effectors in swollen BICs lacking effector puncta. By contrast, fluorescent marker colocalization, gene silencing, and chemical inhibitor studies failed to support a major role for clathrin-independent endocytosis in effector translocation. Effector localization patterns indicated that cytoplasmic effector translocation occurs underneath appressoria before invasive hyphal growth. Taken together, this study provides evidence that cytoplasmic effector translocation is mediated by CME in BICs and suggests a role for M. oryzae effectors in coopting plant endocytosis.


Assuntos
Ascomicetos , Magnaporthe , Oryza , Oryza/genética , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Ascomicetos/metabolismo , Doenças das Plantas/microbiologia
2.
Plant Cell ; 35(8): 2736-2749, 2023 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-37233025

RESUMO

Understanding gene regulatory networks is essential to elucidate developmental processes and environmental responses. Here, we studied regulation of a maize (Zea mays) transcription factor gene using designer transcription activator-like effectors (dTALes), which are synthetic Type III TALes of the bacterial genus Xanthomonas and serve as inducers of disease susceptibility gene transcription in host cells. The maize pathogen Xanthomonas vasicola pv. vasculorum was used to introduce 2 independent dTALes into maize cells to induced expression of the gene glossy3 (gl3), which encodes a MYB transcription factor involved in biosynthesis of cuticular wax. RNA-seq analysis of leaf samples identified, in addition to gl3, 146 genes altered in expression by the 2 dTALes. Nine of the 10 genes known to be involved in cuticular wax biosynthesis were upregulated by at least 1 of the 2 dTALes. A gene previously unknown to be associated with gl3, Zm00001d017418, which encodes aldehyde dehydrogenase, was also expressed in a dTALe-dependent manner. A chemically induced mutant and a CRISPR-Cas9 mutant of Zm00001d017418 both exhibited glossy leaf phenotypes, indicating that Zm00001d017418 is involved in biosynthesis of cuticular waxes. Bacterial protein delivery of dTALes proved to be a straightforward and practical approach for the analysis and discovery of pathway-specific genes in maize.


Assuntos
Fatores de Transcrição , Zea mays , Zea mays/genética , Zea mays/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ativação Transcricional , Bactérias/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Ceras/metabolismo
3.
Int J Mol Sci ; 24(3)2023 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-36768506

RESUMO

Post-translational modifications of chromatin structure by histone acetyltransferase (HATs) play a pivotal role in the regulation of gene expression and diverse biological processes. However, the function of GNAT family HATs, especially Elp3, in the opportunistic human pathogenic fungus Aspergillus fumigatus is largely unknown. To investigate the roles of the GNAT family HATs Elp3 and GcnE in the A. fumigatus, we have generated and characterized individual null Δelp3 and ΔgcnE mutants. The radial growth of fungal colonies was significantly decreased by the loss of elp3 or gcnE, and the number of asexual spores (conidia) in the ΔgcnE mutant was significantly reduced. Moreover, the mRNA levels of the key asexual development regulators were also significantly low in the ΔgcnE mutant compared to wild type (WT). Whereas both the Δelp3 and ΔgcnE mutants were markedly impaired in the formation of adherent biofilms, the ΔgcnE mutant showed a complete loss of surface structure and of intercellular matrix. The ΔgcnE mutant responded differently to oxidative stressors and showed significant susceptibility to triazole antifungal agents. Furthermore, Elp3 and GcnE function oppositely in the production of secondary metabolites, and the ΔgcnE mutant showed attenuated virulence. In conclusion, Elp3 and GcnE are associated with diverse biological processes and can be potential targets for controlling the pathogenic fungus.


Assuntos
Aspergillus fumigatus , Proteínas Fúngicas , Humanos , Aspergillus fumigatus/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Histona Acetiltransferases/genética , Histona Acetiltransferases/metabolismo , Virulência/genética , Esporos Fúngicos , Regulação Fúngica da Expressão Gênica
4.
Plant Biotechnol J ; 20(9): 1819-1832, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35656643

RESUMO

Increasing populations and temperatures are expected to escalate food demands beyond production capacities, and the development of maize lines with better performance under heat stress is desirable. Here, we report that constitutive ectopic expression of a heterologous glutaredoxin S17 from Arabidopsis thaliana (AtGRXS17) can provide thermotolerance in maize through enhanced chaperone activity and modulation of heat stress-associated gene expression. The thermotolerant maize lines had increased protection against protein damage and yielded a sixfold increase in grain production in comparison to the non-transgenic counterparts under heat stress field conditions. The maize lines also displayed thermotolerance in the reproductive stages, resulting in improved pollen germination and the higher fidelity of fertilized ovules under heat stress conditions. Our results present a robust and simple strategy for meeting rising yield demands in maize and, possibly, other crop species in a warming global environment.


Assuntos
Arabidopsis , Termotolerância , Arabidopsis/genética , Grão Comestível/genética , Oxirredução , Termotolerância/genética , Zea mays/genética
5.
Phys Rev Lett ; 128(19): 197702, 2022 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-35622049

RESUMO

We performed microwave spectroscopy of an InAs nanowire between superconducting contacts implementing a finite-length, multichannel Josephson weak link. Certain features in the spectra, such as the splitting by spin-orbit interactions of the transition lines among Andreev states, have been already understood in terms of noninteracting models. However, we identify here additional transitions, which evidence the presence of Coulomb interactions. By combining experimental measurements and model calculations, we reach a qualitative understanding of these very rich Andreev spectra.

6.
Proc Natl Acad Sci U S A ; 116(42): 20938-20946, 2019 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-31575748

RESUMO

Plants are vulnerable to disease through pathogen manipulation of phytohormone levels, which otherwise regulate development, abiotic, and biotic responses. Here, we show that the wheat pathogen Xanthomonas translucens pv. undulosa elevates expression of the host gene encoding 9-cis-epoxycarotenoid dioxygenase (TaNCED-5BS), which catalyzes the rate-limiting step in the biosynthesis of the phytohormone abscisic acid and a component of a major abiotic stress-response pathway, to promote disease susceptibility. Gene induction is mediated by a type III transcription activator-like effector. The induction of TaNCED-5BS results in elevated abscisic acid levels, reduced host transpiration and water loss, enhanced spread of bacteria in infected leaves, and decreased expression of the central defense gene TaNPR1 The results represent an appropriation of host physiology by a bacterial virulence effector.


Assuntos
Ácido Abscísico/metabolismo , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Plantas/biossíntese , Triticum/microbiologia , Xanthomonas/fisiologia , Dioxigenases/genética , Dioxigenases/metabolismo , Suscetibilidade a Doenças , Regulação da Expressão Gênica de Plantas , Interações Hospedeiro-Patógeno , Doenças das Plantas/imunologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Triticum/genética , Triticum/imunologia , Triticum/metabolismo , Virulência , Xanthomonas/patogenicidade
7.
J Interv Cardiol ; 2021: 6698582, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34366721

RESUMO

INTRODUCTION: Biolimus-eluting stents (BES) are known to be superior to bare-metal stents. This study aims to evaluate the safety and efficacy of BES compared to other drug-eluting stents (DES) based on big data from the Korea Acute Myocardial Infarction Registry (KAMIR). METHODS: The study analyzed a total of 9,759 acute myocardial infarction (AMI) patients who underwent percutaneous coronary intervention (PCI) with DES. Total death, cardiac death, recurrent MI, revascularization, stent thrombosis, target lesion failure (TLF, composite of cardiac death, recurrent myocardial infarction (MI), and target lesion revascularization), and major adverse cardiac events (MACE, composite of total death, recurrent MI, and revascularization) were analyzed in patients with AMI up to three years. Study populations were divided into BES (n = 2,020), everolimus-eluting stents (EES, n = 5,293), and zotarolimus-eluting stents (ZES, n = 2,446) groups. RESULTS: To adjust baseline potential confounders, an inverse probability weighting (IPTW) analysis was performed. After IPTW, at three years, total death (7.2%, 8.6%, and 9.5%, P < 0.001), cardiac death (4.1%, 5.3%, and 6.6%, P < 0.001), recurrent MI (1.6%, 2.6%, and 3.2%, P < 0.001), TLF (6.5%, 8.1%, and 9.1%, P < 0.001), and MACE (15.8%, 17.5%, and 18.2%, P < 0.001) were lowest in the BES group compared with the other DES groups in AMI patients. During the 3-year clinical follow-up, the BES group showed better outcomes of MACE (hazard ratio (HR), 0.773; 95% confidence interval (CI), 0.676-0.884; P < 0.001), TLF (HR, 0.659; 95% CI, 0.538-0.808; P < 0.001), total death (HR, 0.687; 95% CI, 0.566-0.835; P < 0.001), and cardiac death (HR,0.593; 95% CI, 0.462-0.541; P < 0.001) than the EES groups. CONCLUSIONS: In this study, BES was superior to EES or ZES in reducing total death, cardiac death, TLF, and MACE in AMI patients.


Assuntos
Stents Farmacológicos , Infarto do Miocárdio , Intervenção Coronária Percutânea , Antagonistas de Receptores de Angiotensina , Inibidores da Enzima Conversora de Angiotensina , Stents Farmacológicos/efeitos adversos , Humanos , Masculino , Infarto do Miocárdio/epidemiologia , Intervenção Coronária Percutânea/efeitos adversos , Desenho de Prótese , Sistema de Registros , República da Coreia/epidemiologia , Stents , Volume Sistólico , Resultado do Tratamento , Função Ventricular Esquerda
8.
Physiol Plant ; 173(3): 1263-1279, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34392538

RESUMO

Sessile organisms such as plants have adopted diverse reactive oxygen species (ROS) scavenging mechanisms to mitigate damage under abiotic stress conditions. Though CGFS-type glutaredoxin (GRX) genes are important regulators of ROS homeostasis, each of their functions in crop plants have not yet been well understood. We performed a targeted mutagenesis analysis of four CGFS-type GRXs (SlGRXS14, SlGRXS15, SlGRXS16, and SlGRXS17) in tomato plants (Solanum lycopersicum) using a multiplex clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 system and found that Slgrxs mutants were more sensitive to various abiotic stresses compared with the wild-type tomatoes. Slgrxs15 mutants were embryonic lethal. Single, double, and triple combinations of Slgrxs14, 16, and 17 mutants were examined under heat, chilling, drought, heavy metal toxicity, nutrient deficiency, and short photoperiod stresses. Slgrxs14 and 17 mutants showed hypersensitivity to almost all stresses while Slgrxs16 mutants were affected by chilling stress and showed milder sensitivity to other stresses. Additionally, Slgrxs14 and 17 mutants showed delayed flowering time. Our results indicate that the CGFS-type SlGRXs have specific roles against abiotic stresses, providing valuable resources to develop tomato and, possibly, other crop species that are tolerant to multiple abiotic stresses by genetic engineering.


Assuntos
Solanum lycopersicum , Secas , Glutarredoxinas/genética , Solanum lycopersicum/genética , Mutação , Estresse Fisiológico/genética
9.
Int J Mol Sci ; 22(10)2021 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-34069397

RESUMO

Drought stress is a major constraint in global maize production, causing almost 30-90% of the yield loss depending upon growth stage and the degree and duration of the stress. Here, we report that ectopic expression of Arabidopsis glutaredoxin S17 (AtGRXS17) in field grown maize conferred tolerance to drought stress during the reproductive stage, which is the most drought sensitive stage for seed set and, consequently, grain yield. AtGRXS17-expressing maize lines displayed higher seed set in the field, resulting in 2-fold and 1.5-fold increase in yield in comparison to the non-transgenic plants when challenged with drought stress at the tasseling and silking/pollination stages, respectively. AtGRXS17-expressing lines showed higher relative water content, higher chlorophyll content, and less hydrogen peroxide accumulation than wild-type (WT) control plants under drought conditions. AtGRXS17-expressing lines also exhibited at least 2-fold more pollen germination than WT plants under drought stress. Compared to the transgenic maize, WT controls accumulated higher amount of proline, indicating that WT plants were more stressed over the same period. The results present a robust and simple strategy for meeting rising yield demands in maize under water limiting conditions.


Assuntos
Glutarredoxinas/genética , Glutarredoxinas/metabolismo , Estresse Fisiológico/genética , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Secas , Expressão Ectópica do Gene/genética , Grão Comestível/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Tolerância ao Sal/genética , Estresse Fisiológico/fisiologia , Termotolerância/genética , Zea mays/genética
10.
Phys Rev Lett ; 125(18): 187702, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-33196222

RESUMO

It has been argued that fluctuations of fermion parity are harmful for the demonstration of non-Abelian anyonic statistics. Here, we demonstrate a striking exception in which such fluctuations are actively used. We present a theory of coherent electron transport from a tunneling tip into a Corbino geometry Josephson junction where four Majorana bound states (MBSs) rotate. While the MBSs rotate, electron tunneling happens from the tip to one of the MBSs thereby changing the fermion parity of the MBSs. The tunneling events in combination with the rotation allow us to identify a novel braiding operator that does not commute with the braiding cycles in the absence of tunneling, revealing the non-Abelian nature of MBSs. The time-averaged tunneling current exhibits resonances as a function of the tip voltage with a period that is a direct consequence of the interference between the noncommuting braiding operations. Our work opens up a possibility for utilizing parity nonconserving processes to control non-Abelian states.

11.
Phys Rev Lett ; 125(7): 077701, 2020 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-32857526

RESUMO

Spectral properties of a quantum circuit are efficiently read out by monitoring the resonance frequency shift it induces in a microwave resonator coupled to it. When the two systems are strongly detuned, theory attributes the shift to an effective resonator capacitance or inductance that depends on the quantum circuit state. At small detuning, the shift arises from the exchange of virtual photons, as described by the Jaynes-Cummings model. Here we present a theory bridging these two limits and illustrate, with several examples, its necessity for a general description of quantum circuits readout.

12.
Clin Exp Pharmacol Physiol ; 45(6): 499-506, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29266345

RESUMO

Recently, meta-analysis studies reported that hyperuricaemia is associated with higher incidence of type 2 diabetes mellitus (T2DM), however, there are limited data on the Asian population. The aim of this observational study is to estimate the long-term impact of hyperuricaemia on the new-onset T2DM and cardiovascular events. This study is based on a single-centre, all-comers, and large retrospective cohort. Subjects that visited from January 2004 to February 2014 were enrolled using the electronic database of Korea University Guro Hospital. A total of 10 505 patients without a history of T2DM were analyzed for uric acid, fasting glucose and haemoglobin (Hb) A1c level. Inclusion criteria included both Hb A1c <5.7% and fasting glucose level <100 mg/dL without T2DM. Hyperuricaemia was defined as a uric acid level ≥7.0 mg/dL in men, and ≥6.5 mg/dL in women. To adjust baseline confounders, a propensity score matching (PSM) analysis was performed. The impact of hyperuricaemia on the new-onset T2DM and cardiovascular events were compared with the non-hyperuricaemia during the 5-year clinical follow-up. After PSM, baseline characteristics of both groups were balanced. In a 5-year follow-up, the hyperuricaemia itself was a strong independent predictor of the incidence of new-onset T2DM (HR, 1.78; 95% CI, 1.12 to 2.8). Hyperuricaemia was a strong independent predictor of new-onset T2DM, which suggests a substantial implication for a correlation between uric acid concentration and insulin resistance (or insulin sensitivity). Also, hyperuricaemia is substantially implicated in cardiovascular risks and the further long-term cardiovascular events in the crude population, but it is not an independent predictor of long-term cardiovascular mortality in the matched population.


Assuntos
Povo Asiático/estatística & dados numéricos , Diabetes Mellitus Tipo 2/complicações , Hiperuricemia/complicações , Idoso , Diabetes Mellitus Tipo 2/epidemiologia , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade
13.
Biochem Biophys Res Commun ; 491(4): 1034-1039, 2017 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-28780355

RESUMO

Abiotic stresses are a major factor limiting crop growth and productivity. The Arabidopsis thaliana glutaredoxin S17 (AtGRXS17) gene has conserved functions in plant tolerance to heat and chilling stress in Arabidopsis and, when expressed ectopically, in tomato. Here, we report that ectopic expression of AtGRXS17 in tomato also enhanced tolerance to drought and oxidative stress. AtGRXS17-expressing tomato plants contained twice the shoot water content compared to wild-type plants under water limiting conditions. This enhanced drought tolerance correlated with a higher maximal photosynthetic efficiency of photosystem II (Fv/Fm). Ectopic AtGRXS17-expression was concomitant with the expression of Solanum lycopersicum catalase 1 (SlCAT1) and mitigated defects in the growth of primary roots in response to methyl viologen exposure. In addition, AtGRXS17 expression was found to prolong elevated expression levels of the Solanum lycopersicum ABA-responsive element binding protein 1 (SlAREB1) during drought stress. The findings demonstrate that expression of AtGRXS17 can simultaneously improve the tolerance of tomato, and possibly other agriculturally important crops, to drought, heat, and chilling stresses.


Assuntos
Proteínas de Arabidopsis/genética , Secas , Glutarredoxinas/genética , Solanum lycopersicum/genética , Estresse Fisiológico/genética , Arabidopsis , Proteínas de Arabidopsis/metabolismo , Dessecação , Glutarredoxinas/metabolismo
14.
Plant Cell Environ ; 39(2): 377-92, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26296956

RESUMO

Calcium (Ca(2+) ) is vital for plant growth, development, hormone response and adaptation to environmental stresses, yet the mechanisms regulating plant cytosolic Ca(2+) homeostasis are not fully understood. Here, we characterize an Arabidopsis Ca(2+) -regulated Na(+) /Ca(2+) exchanger AtNCL that regulates Ca(2+) and multiple physiological processes. AtNCL was localized to the tonoplast in yeast and plant cells. AtNCL appeared to mediate sodium (Na(+) ) vacuolar sequestration and meanwhile Ca(2+) release. The EF-hand domains within AtNCL regulated Ca(2+) binding and transport of Ca(2+) and Na(+) . Plants with diminished AtNCL expression were more tolerant to high CaCl2 but more sensitive to both NaCl and auxin; heightened expression of AtNCL rendered plants more sensitive to CaCl2 but tolerant to NaCl. AtNCL expression appeared to be regulated by the diurnal rhythm and suppressed by auxin. DR5::GUS expression and root responses to auxin were altered in AtNCL mutants. The auxin-induced suppression of AtNCL was attenuated in SLR/IAA14 and ARF6/8 mutants. The mutants with altered AtNCL expression also altered flowering time and FT and CO expression; FT may mediate AtNCL-regulated flowering time change. Therefore, AtNCL is a vacuolar Ca(2+) -regulated Na(+) /Ca(2+) exchanger that regulates auxin responses and flowering time.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Cálcio/metabolismo , Ritmo Circadiano , Flores/fisiologia , Ácidos Indolacéticos/metabolismo , Transdução de Sinais , Trocador de Sódio e Cálcio/metabolismo , Sequência de Aminoácidos , Arabidopsis/genética , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Cátions , Motivos EF Hand , Regulação da Expressão Gênica de Plantas , Técnicas de Inativação de Genes , Proteínas de Fluorescência Verde/metabolismo , Homeostase , Membranas Intracelulares/metabolismo , Dados de Sequência Molecular , Mutação/genética , Fenótipo , Células Vegetais/metabolismo , Transporte Proteico , Saccharomyces cerevisiae/metabolismo , Sódio/metabolismo , Trocador de Sódio e Cálcio/química , Trocador de Sódio e Cálcio/genética , Fatores de Tempo , Vacúolos/metabolismo
15.
Plant Cell Environ ; 38(11): 2223-38, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25754420

RESUMO

Potassium (K(+) ) is essential for plant growth and development, yet the molecular identity of many K(+) transporters remains elusive. Here we characterized cation/H(+) exchanger (CHX) 14 as a plasma membrane K(+) transporter. CHX14 expression was induced by elevated K(+) and histochemical analysis of CHX14 promoter::GUS transgenic plants indicated that CHX14 was expressed in xylem parenchyma of root and shoot vascular tissues of seedlings. CHX14 knockout (chx14) and CHX14 overexpression seedlings displayed different growth phenotypes during K(+) stress as compared with wild-type seedlings. Roots of mutant seedlings displayed higher K(+) uptake rates than wild-type roots. CHX14 expression in yeast cells deficient in K(+) uptake renders the mutant cells more sensitive to deficiencies of K(+) in the medium. CHX14 mediates K(+) efflux in yeast cells loaded with high K(+) . Uptake experiments using (86) Rb(+) as a tracer for K(+) with both yeast and plant mutants demonstrated that CHX14 expression in yeast and in planta mediated low-affinity K(+) efflux. Functional green fluorescent protein (GFP)-tagged versions of CHX14 were localized to both the yeast and plant plasma membranes. Taken together, we suggest that CHX14 is a plasma membrane K(+) efflux transporter involved in K(+) homeostasis and K(+) recirculation.


Assuntos
Proteínas de Arabidopsis/fisiologia , Arabidopsis/metabolismo , Potássio/metabolismo , Trocadores de Sódio-Hidrogênio/fisiologia , Arabidopsis/genética , Proteínas de Arabidopsis/análise , Proteínas de Arabidopsis/genética , Membrana Celular/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Homeostase , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Brotos de Planta/genética , Brotos de Planta/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Plântula/genética , Plântula/metabolismo , Trocadores de Sódio-Hidrogênio/análise , Trocadores de Sódio-Hidrogênio/genética
16.
Phys Rev Lett ; 115(24): 246403, 2015 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-26705644

RESUMO

A phase from an adiabatic exchange of Majorana bound states (MBS) reveals their exotic anyonic nature. For detecting this exchange phase, we propose an experimental setup consisting of a Corbino geometry Josephson junction on the surface of a topological insulator, in which two MBS at zero energy can be created and rotated. We find that if a metallic tip is weakly coupled to a point on the junction, the time-averaged differential conductance of the tip-Majorana coupling shows peaks at the tip voltages eV=±(α-2πl)ℏ/T_{J}, where α=π/2 is the exchange phase of the two circulating MBS, T_{J} is the half rotation time of MBS, and l an integer. This result constitutes a clear experimental signature of Majorana fermion exchange.

17.
Mol Plant Microbe Interact ; 27(3): 296-304, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24405031

RESUMO

Vector-borne viruses are a threat to human, animal, and plant health worldwide, requiring the development of novel strategies for their control. Tomato spotted wilt virus (TSWV) is one of the 10 most economically significant plant viruses and, together with other tospoviruses, is a threat to global food security. TSWV is transmitted by thrips, including the western flower thrips, Frankliniella occidentalis. Previously, we demonstrated that the TSWV glycoprotein GN binds to thrips vector midguts. We report here the development of transgenic plants that interfere with TSWV acquisition and transmission by the insect vector. Tomato plants expressing GN-S protein supported virus accumulation and symptom expression comparable with nontransgenic plants. However, virus titers in larval insects exposed to the infected transgenic plants were three-log lower than insects exposed to infected nontransgenic control plants. The negative effect of the GN-S transgenics on insect virus titers persisted to adulthood, as shown by four-log lower virus titers in adults and an average reduction of 87% in transmission efficiencies. These results demonstrate that an initial reduction in virus infection of the insect can result in a significant decrease in virus titer and transmission over the lifespan of the vector, supportive of a dose-dependent relationship in the virus-vector interaction. These findings demonstrate that plant expression of a viral protein can be an effective way to block virus transmission by insect vectors.


Assuntos
Insetos Vetores/virologia , Doenças das Plantas/virologia , Solanum lycopersicum/virologia , Tisanópteros/virologia , Tospovirus/fisiologia , Proteínas Virais/genética , Animais , Anticorpos Antivirais , Ensaio de Imunoadsorção Enzimática , Expressão Gênica , Glicoproteínas/genética , Glicoproteínas/metabolismo , Proteínas de Fluorescência Verde , Larva , Solanum lycopersicum/citologia , Solanum lycopersicum/genética , Doenças das Plantas/prevenção & controle , Plantas Geneticamente Modificadas , Coelhos , Proteínas Recombinantes de Fusão , Tospovirus/genética , Tospovirus/imunologia , Proteínas Virais/metabolismo
18.
Sci Rep ; 14(1): 542, 2024 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-38177401

RESUMO

In this study, the deoxidation process for off-grade titanium (Ti) sponge using magnesium (Mg) metal with a wire mesh strainer type of crucible was developed. Ti hydride (TiH2) feedstock, which was prepared by hydrogenating off-grade Ti sponge, was deoxidized using Mg in a molten magnesium chloride-potassium chloride salt at 933 K under an argon and 20% hydrogen (H2) mixed gas atmosphere. After deoxidation, the residual Mg-containing salt was separated in situ from the crucible to investigate the feasibility of minimizing salt loss during the leaching and production of pure TiH2. The results showed that the presence of residual Mg-containing salt inside the crucible strongly influenced whether a mixture of Ti and TiH2 or pure TiH2 was produced. When the salt was not sufficiently separated, a mixture of Ti and TiH2 was obtained and its oxygen (O) concentration was 0.121 mass% under certain conditions. Meanwhile, pure TiH2 was obtained by increasing the H2 gas flow rate during deoxidation. Therefore, these results demonstrate that the decrease of O concentration to below 0.180 mass% and the minimal loss of the salt are feasible.

19.
Plant J ; 71(5): 824-35, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22563738

RESUMO

Blossom-end rot (BER) in tomato fruit (Solanum lycopersicum) is believed to be a calcium (Ca²âº) deficiency disorder, but the mechanisms involved in its development are poorly understood. Our hypothesis is that high expression of pectin methylesterases (PMEs) increases Ca²âº bound to the cell wall, subsequently decreasing Ca²âº available for other cellular functions and thereby increasing fruit susceptibility to BER. The objectives of this study were to evaluate the effect of PME expression, and amount of esterified pectins and Ca²âº bound to the cell wall on BER development in tomato fruit. Wild-type and PME-silenced tomato plants were grown in a greenhouse. At full bloom, flowers were pollinated and Ca²âº was no longer provided to the plants to induce BER. Our results show that suppressing expression of PMEs in tomato fruit reduced the amount of Ca²âº bound to the cell wall, and also reduced fruit susceptibility to BER. Both the wild-type and PME-silenced fruit had similar total tissue, cytosolic and vacuolar Ca²âº concentrations, but wild-type fruit had lower water-soluble apoplastic Ca²âº content and higher membrane leakage, one of the first symptoms of BER. Our results suggest that apoplastic water-soluble Ca²âº concentration influences fruit susceptibility to Ca²âº deficiency disorders.


Assuntos
Cálcio/metabolismo , Hidrolases de Éster Carboxílico/metabolismo , Frutas/crescimento & desenvolvimento , Doenças das Plantas/etiologia , Solanum lycopersicum/enzimologia , Parede Celular/metabolismo , Produtos Agrícolas/enzimologia , Produtos Agrícolas/crescimento & desenvolvimento , Citosol/metabolismo , Frutas/enzimologia , Imuno-Histoquímica , Solanum lycopersicum/crescimento & desenvolvimento , Pectinas/metabolismo , Vacúolos/metabolismo
20.
Ultrasonics ; 134: 107063, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37300907

RESUMO

To enhance the effectiveness and safety of focused ultrasound (FUS) therapy, ultrasound image-based guidance and treatment monitoring are crucial. However, the use of FUS transducers for both therapy and imaging is impractical due to their low spatial resolution, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). To address this issue, we propose a new method that significantly improve the quality of images obtained by a FUS transducer. The proposed method employs coded excitation to enhance SNR and Wiener deconvolution to solve the problem of low axial resolution resulting from the narrow spectral bandwidth of FUS transducers. Specifically, the method eliminates the impulse response of a FUS transducer from received ultrasound signals using Wiener deconvolution, and pulse compression is performed using a mismatched filter. Simulation and commercial phantom experiments confirmed that the proposed method significantly improves the quality of images acquired by the FUS transducer. The -6 dB axial resolution was improved 1.27 mm to 0.37 mm that was similar to the resolution achieved by the imaging transducer, i.e., 0.33 mm. SNR and CNR also increased from 16.5 dB and 0.69 to 29.1 dB and 3.03, respectively, that were also similar to those by the imaging transducer (27.8 dB and 3.16). Based on the results, we believe that the proposed method has great potential to enhance the clinical utility of FUS transducers in ultrasound image-guided therapy.


Assuntos
Compressão de Dados , Compressão de Dados/métodos , Ultrassonografia/métodos , Razão Sinal-Ruído , Simulação por Computador , Imagens de Fantasmas , Transdutores
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