115 research outputs found

    Light Plays an Essential Role in Intracellular Distribution of Auxin Efflux Carrier PIN2 in Arabidopsis thaliana

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    BACKGROUND: Light plays a key role in multiple plant developmental processes. It has been shown that root development is modulated by shoot-localized light signaling and requires shoot-derived transport of the plant hormone, auxin. However, the mechanism by which light regulates root development is not largely understood. In plants, the endogenous auxin, indole-3-acetic acid, is directionally transported by plasma-membrane (PM)-localized auxin influx and efflux carriers in transporting cells. Remarkably, the auxin efflux carrier PIN proteins exhibit asymmetric PM localization, determining the polarity of auxin transport. Similar to PM-resident receptors and transporters in animal and yeast cells, PIN proteins undergo constitutive cycling between the PM and endosomal compartments. Auxin plays multiple roles in PIN protein intracellular trafficking, inhibiting PIN2 endocytosis at some concentrations and promoting PIN2 degradation at others. However, how PIN proteins are turned over in plant cells is yet to be addressed. METHODOLOGY AND PRINCIPLE FINDINGS: Using laser confocal scanning microscopy, and physiological and molecular genetic approaches, here, we show that in dark-grown seedlings, the PM localization of auxin efflux carrier PIN2 was largely reduced, and, in addition, PIN2 signal was detected in vacuolar compartments. This is in contrast to light-grown seedlings where PIN2 was predominantly PM-localized. In light-grown plants after shift to dark or to continuous red or far-red light, PIN2 also accumulated in vacuolar compartments. We show that PIN2 vacuolar targeting was derived from the PM via endocytic trafficking and inhibited by HY5-dependent light signaling. In addition, the ubiquitin 26S proteasome is involved in the process, since its inhibition by mutations in COP9 and a proteasome inhibitor MG132 impaired the process. CONCLUSIONS AND SIGNIFICANCE: Collectively, our data indicate that light plays an essential role in PIN2 intracellular trafficking, promoting PM-localization in the presence of light and, on the other hand, vacuolar targeting for protein degradation in the absence of light. Based on these results, we postulate that light regulation of root development is mediated at least in part by changes in the intracellular distribution of auxin efflux carriers, PIN proteins, in response to the light environment

    Male, National, and Religious Collective Narcissism Predict Sexism

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    Results of three cross-sectional studies indicate that sexism in Poland is associated with collective narcissism—a belief that one’s own group’s (the in-group’s) exaggerated exceptionality is not sufficiently recognized by others—with reference to three social identities: male, religious, and national. In Study 1 (n = 329), male collective narcissism was associated with sexism. This relationship was sequentially mediated by precarious manhood and traditional gender beliefs. In Study 2 (n = 877), Catholic collective narcissism predicted tolerance of violence against women (among men and women) over and above religious fundamentalism and in contrast to intrinsic religiosity. In Study 3 (n = 1070), national collective narcissism was associated with hostile sexism among men and women and with benevolent sexism more strongly among women than among men. In contrast, national in-group satisfaction—a belief that the nation is of a high value—predicted rejection of benevolent and hostile sexism among women but was positively associated with hostile and benevolent sexism among men. Among men and women collective narcissism was associated with tolerance of domestic violence against women, whereas national in-group satisfaction was associated with rejection of violence against women

    Plant hormone transporters: what we know and what we would like to know

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    The far side of auxin signaling: fundamental cellular activities and their contribution to a defined growth response in plants

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    Effect of vernalizing temperature on the level of plant hormones in embryos of germinating grains of winter and spring wheat

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    In embryos of grains of winter and spring wheat germinating at temperature of 1.8—2.0°C the levels of auxins, gibberellins, cytokinins and abscisic acid-like inhibitor were determined. The analyses were performed after 5, 10, 20, 40 and 60 days of chilling. The levels of these hormones were also determined in embryos of grains germinated at 22°C being in the same growth stage as embryos taken from chilled grains. It was stated, that during the germination at vernalizing temperature the level of auxins, GAs and cytokinins increased in embryos of both varietes. The level of these hormones in winter wheat was however higher. The amount of growth inhibitor increased at the beginning of germination in embryos of both wheats and afterwards decreased. It was concluded that the above mentioned changes in the level of auxins, cytokinins and ABA had no direct relation to the process of vernalization. However, the changes in the levels of gibberellins found in embryos of winter wheat during the thermoinduction may be directly connected with the vernalization process

    Analiza porównawcza występowania chlorofenoli i innych związków chloroaromatycznych w wodzie pitnej pochodzącej z ujęcia powierzchniowego i głębinowego

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    Dotychczas niewiele miejsca poświęcono badaniom obecności trwałych i silnie toksycznych związków chloroaromatycznych, tj. chlorofenoli, chlorobenzenów i chlorowanych bifenyli w wodzie pitnej pochodzącej z ujęć głębinowych. W niniejszej pracy przeprowadzono sezonową analizę porównawczą dotyczącą obecności tych substancji w wodzie pitnej pochodzącej z ujęcia powierzchniowego i głębinowego wybierając jako obszar badawczy aglomerację łódzką. Analizy przeprowadzono z wykorzystaniem techniki chromatografii gazowej sprzęgniętej ze spektrometrią mas. Przeprowadzone analizy wskazały na powszechnie występowanie w badanych próbach fenolu (30–130 ng/L), chlorofenoli (20–520 ng/L) i chlorobenzenu (70–240 ng/L). W nielicznych próbach wykryto także chlorokatechole (20–60 ng/L), chlorowane metoksyfenole (20–520 ng/L) oraz polichlorowane bifenyle (5–18 ng/L). Wyniki badań wskazały, że 2,4,6-trichlorofenol i pentachlorofenol występowały w wyższych stężeniach w wodzie pitnej pochodzącej z ujęcia głębinowego. Ponadto, najwyższe całkowite stężenia chlorofenoli oznaczono w sezonie jesiennym zarówno w próbach wody pitnej pochodzących z ujęcia powierzchniowego, jak i głębinowego

    CyProF - insights from a framework for designing cyber-physical systems in production environments

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    There is little experience in integrating cyber-physical systems (CPS) in production environments nowadays. A coordinated framework with reference architecture, methodology and procedural model can support the adaption of CPS by providing a pre-defined structure and guidelines. This paper describes such a framework, named CyProF, for designing CPS-based solutions in production environments. Engineers are supported by this framework in handling the complexity during the design phase. Additionally, this paper explains how the framework was used in a use case to reduce engineering efforts for a CPS-based demonstrator
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