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Author

Petr Skůpa

Other affiliations: Charles University in Prague
Bio: Petr Skůpa is an academic researcher from Academy of Sciences of the Czech Republic. The author has contributed to research in topics: Auxin & Auxin homeostasis. The author has an hindex of 10, co-authored 15 publications receiving 2137 citations. Previous affiliations of Petr Skůpa include Charles University in Prague.

Papers
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Journal ArticleDOI
TL;DR: This Article contains errors in Figs 1, 4, and Supplementary Fig. S6, for which the author apologizes.
Abstract: Nature Communications 3: Article number: 941 (2012); Published: 3 July 2012; Updated: 5 February 2013. This Article contains errors in Figs 1, 4, and Supplementary Fig. S6, for which we apologize. In Fig. 1b, the Col picture was inadvertently duplicated from the image below it. In addition, the legend should have defined the scale bar for panel e as 1 μm.

585 citations

Journal ArticleDOI
25 Jun 2009-Nature
TL;DR: It is shown that Arabidopsis thaliana PIN5, an atypical member of the PIN gene family, encodes a functional auxin transporter that is required for auxin-mediated development and represents an ancient event during the evolution of land plants.
Abstract: The plant signalling molecule auxin provides positional information in a variety of developmental processes by means of its differential distribution (gradients) within plant tissues. Thus, cellular auxin levels often determine the developmental output of auxin signalling. Conceptually, transmembrane transport and metabolic processes regulate the steady-state levels of auxin in any given cell. In particular, PIN auxin-efflux-carrier-mediated, directional transport between cells is crucial for generating auxin gradients. Here we show that Arabidopsis thaliana PIN5, an atypical member of the PIN gene family, encodes a functional auxin transporter that is required for auxin-mediated development. PIN5 does not have a direct role in cell-to-cell transport but regulates intracellular auxin homeostasis and metabolism. PIN5 localizes, unlike other characterized plasma membrane PIN proteins, to endoplasmic reticulum (ER), presumably mediating auxin flow from the cytosol to the lumen of the ER. The ER localization of other PIN5-like transporters (including the moss PIN) indicates that the diversification of PIN protein functions in mediating auxin homeostasis at the ER, and cell-to-cell auxin transport at the plasma membrane, represent an ancient event during the evolution of land plants.

502 citations

Journal ArticleDOI
TL;DR: A large group of PIN proteins, including the most ancient members known from mosses, localize to the endoplasmic reticulum and they regulate the subcellular compartmentalization of auxin and thus auxin metabolism.
Abstract: The PIN-FORMED (PIN) proteins are secondary transporters acting in the efflux of the plant signal molecule auxin from cells. They are asymmetrically localized within cells and their polarity determines the directionality of intercellular auxin flow. PIN genes are found exclusively in the genomes of multicellular plants and play an important role in regulating asymmetric auxin distribution in multiple developmental processes, including embryogenesis, organogenesis, tissue differentiation and tropic responses. All PIN proteins have a similar structure with amino- and carboxy-terminal hydrophobic, membrane-spanning domains separated by a central hydrophilic domain. The structure of the hydrophobic domains is well conserved. The hydrophilic domain is more divergent and it determines eight groups within the protein family. The activity of PIN proteins is regulated at multiple levels, including transcription, protein stability, subcellular localization and transport activity. Different endogenous and environmental signals can modulate PIN activity and thus modulate auxin-distribution-dependent development. A large group of PIN proteins, including the most ancient members known from mosses, localize to the endoplasmic reticulum and they regulate the subcellular compartmentalization of auxin and thus auxin metabolism. Further work is needed to establish the physiological importance of this unexpected mode of auxin homeostasis regulation. Furthermore, the evolution of PIN-based transport, PIN protein structure and more detailed biochemical characterization of the transport function are important topics for further studies.

441 citations

Journal ArticleDOI
TL;DR: Auxin is a key coordinative signal required for many aspects of plant development and its levels are controlled by auxin metabolism and intercellular auxin transport, and a member of PIN auxin transporter family, PIN8 is expressed in male gametophyte of Arabidopsis thaliana and has a crucial role in pollen development and functionality.
Abstract: Auxin is a key coordinative signal required for many aspects of plant development and its levels are controlled by auxin metabolism and intercellular auxin transport. Here we find that a member of PIN auxin transporter family, PIN8 is expressed in male gametophyte of Arabidopsis thaliana and has a crucial role in pollen development and functionality. Ectopic expression in sporophytic tissues establishes a role of PIN8 in regulating auxin homoeostasis and metabolism. PIN8 co-localizes with PIN5 to the endoplasmic reticulum (ER) where it acts as an auxin transporter. Genetic analyses reveal an antagonistic action of PIN5 and PIN8 in the regulation of intracellular auxin homoeostasis and gametophyte as well as sporophyte development. Our results reveal a role of the auxin transport in male gametophyte development in which the distinct actions of ER-localized PIN transporters regulate cellular auxin homoeostasis and maintain the auxin levels optimal for pollen development and pollen tube growth.

245 citations

Journal ArticleDOI
TL;DR: A model is proposed in which PGP-mediated efflux controls auxin levels in auxin channel-forming cells and, thus, auxin availability for PIN-dependent vectorial auxin movement is proposed.
Abstract: The signalling molecule auxin controls plant morphogenesis via its activity gradients, which are produced by intercellular auxin transport. Cellular auxin efflux is the rate-limiting step in this process and depends on PIN and phosphoglycoprotein (PGP) auxin transporters. Mutual roles for these proteins in auxin transport are unclear, as is the significance of their interactions for plant development. Here, we have analysed the importance of the functional interaction between PIN- and PGP-dependent auxin transport in development. We show by analysis of inducible overexpression lines that PINs and PGPs define distinct auxin transport mechanisms: both mediate auxin efflux but they play diverse developmental roles. Components of both systems are expressed during embryogenesis, organogenesis and tropisms, and they interact genetically in both synergistic and antagonistic fashions. A concerted action of PIN- and PGP-dependent efflux systems is required for asymmetric auxin distribution during these processes. We propose a model in which PGP-mediated efflux controls auxin levels in auxin channel-forming cells and, thus, auxin availability for PIN-dependent vectorial auxin movement.

228 citations


Cited by
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Journal ArticleDOI
TL;DR: The genes that govern the biosynthesis of antioxidant flavonoids are present in liverworts and mosses and are mostly up-regulated as a consequence of severe stress, which suggests that the antioxidant Flavonoid metabolism is a robust trait of terrestrial plants.

1,414 citations

Journal ArticleDOI
20 Mar 2009-Cell
TL;DR: The dynamic, differential distribution of the hormone auxin within plant tissues controls an impressive variety of developmental processes, which tailor plant growth and morphology to environmental conditions.

1,124 citations

Journal ArticleDOI
TL;DR: An overview of energy storage systems as a whole, the metrics that are used to quantify the performance of electrodes, recent strategies that have been investigated to overcome the challenges associated with organic electrode materials, and the use of computational chemistry to design and study new materials and their properties are provided.
Abstract: Organic electrode materials are very attractive for electrochemical energy storage devices because they can be flexible, lightweight, low cost, benign to the environment, and used in a variety of device architectures. They are not mere alternatives to more traditional energy storage materials, rather, they have the potential to lead to disruptive technologies. Although organic electrode materials for energy storage have progressed in recent years, there are still significant challenges to overcome before reaching large-scale commercialization. This review provides an overview of energy storage systems as a whole, the metrics that are used to quantify the performance of electrodes, recent strategies that have been investigated to overcome the challenges associated with organic electrode materials, and the use of computational chemistry to design and study new materials and their properties. Design strategies are examined to overcome issues with capacity/capacitance, device voltage, rate capability, and cycling stability in order to guide future work in the area. The use of low cost materials is highlighted as a direction towards commercial realization.

753 citations

Journal ArticleDOI
TL;DR: This primer discusses how the coordinated activity of several auxin influx and efflux systems, which transport auxin across the plasma membrane, mediates directional auxin flow and contributes to the correct setting of developmental cues in embryogenesis, organogenesis, vascular tissue formation and directional growth in response to environmental stimuli.
Abstract: The differential distribution of the plant signaling molecule auxin is required for many aspects of plant development. Local auxin maxima and gradients arise as a result of local auxin metabolism and, predominantly, from directional cell-to-cell transport. In this primer, we discuss how the coordinated activity of several auxin influx and efflux systems, which transport auxin across the plasma membrane, mediates directional auxin flow. This activity crucially contributes to the correct setting of developmental cues in embryogenesis, organogenesis, vascular tissue formation and directional growth in response to environmental stimuli.

720 citations

Journal ArticleDOI
TL;DR: Plant hormones control most aspects of the plant life cycle by regulating genome expression through interactions among auxin-responsive DNA sequence elements, transcription factors and trans-acting transcriptional repressors.
Abstract: Plant hormones control most aspects of the plant life cycle by regulating genome expression. Expression of auxin-responsive genes involves interactions among auxin-responsive DNA sequence elements, transcription factors and trans-acting transcriptional repressors. Transcriptional output from these auxin signaling complexes is regulated by proteasome-mediated degradation that is triggered by interaction with auxin receptor-E3 ubiquitin ligases such SCF TIR1 . Auxin signaling components are conserved throughout land plant evolution and have proliferated and specialized to control specific developmental processes.

649 citations