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Predicting Arabidopsis Freezing Tolerance and Heterosis in Freezing Tolerance from Metabolite Composition

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Molecular Plant 2010年第1期3卷 224-235页

作者： Marina Korn Tanja Gaetner Alexander Erban Joachim Kopka Joachim Selbig Dirk K. Hincha Max-Planck-lnstitut fur Molekulare Pflanzenphysiologie Am Muhlenberg 1 D-14476 Potsdam Germany Abteilung Bioinformatik Institut for Biochemie und Biologie Universit~t Potsdam Karl-Liebknecht-Str. 24-25 D-14476 Potsdam Germany

Heterosis, or hybrid vigor, is one of the most important tools in plant breeding and has previously been dem- onstrated for plant freezing tolerance. Freezing tolerance is an important trait because it can limit the geographical dis- tribution of plants and their agricultural yield. Plants from temperate climates increase in freezing tolerance during exposure to low, non-freezing temperatures in a process termed ＇cold acclimation＇. Metabolite profiling has indicated a major reprogramming of plant metabolism in the cold, but it has remained unclear in previous studies which of these changes are related to freezing tolerance. In the present study, we have used metabolic profiling to discover combinations of metabolites that predict freezing tolerance and its heterosis in Arabidopsis thaliana. We identified compatible solutes and, in particular, the pathway leading to raffinose as crucial statistical predictors for freezing tolerance and its heterosis, while some TCA cycle intermediates contribute only to predicting the heterotic phenotype. This indicates coordinate links between heterosis and metabolic pathways, suggesting that a limited number of regulatory genes may determine the extent of heterosis in this complex trait. In addition, several unidentified metabolites strongly contributed to the prediction of both freezing tolerance and its heterosis and we present an exemplary analysis of one of these, identifying it as a hexose conjugate.

关键词： Abiotic/environmental stress cold acclimation metabolomics bioinformatics biostatistics Arabidopsis.

Topological protection of partially coherent light

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Photonics Research 2022年第5期10卷 1223-1231页

作者： KONRAD TSCHERNIG GABRIEL MARTINEZ-NICONOFF KURT BUSCH MIGUEL A.BANDRES ARMANDO PEREZ-LEIJA Max-Born-lnstitut 12489 BerlinGermany Humboldt-Universität zu Berlin Institut fur PhysikAG Theoretische Optik&Photonik12489 BerlinGermany Coordinacidn deÓptica Instituto Nacional de AstrofisicaÓpticay Electronica72840 TonantzintlaPueblaMexico CREOL The College of Optics and PhotonicsUniversity of Central FloridaOrlandoFlorida 32816USA

Topological physics exploits concepts from geometry and topology to implement systems capable of guiding waves in an unprecedented fashion.These ideas have led to the development of photonic topological insulators,which are optical systems whose eigenspectral topology allows the creation of light states that propagate along the edge of the system without any coupling into the bulk or backscattering even in the presence of disorder.Indeed,topological protection is a fully coherent effect,and it is not clear to what extent topological effects endure when the wavefronts become partially coherent.Here,we study the interplay of topological protection and the degree of spatial coherence of classical light propagating in disordered photonic topological insulators.Our results reveal the existence of a well-defined spectral window in which partially coherent light is topologically protected.This opens up the design space to a wider selection of light sources,possibly yielding smaller,cheaper,and more robust devices based on the topological transport of light.

关键词： topological coherent topology

GEOCHEMICALLY CONTROLLED CALCITE PRECIPITATION BY CO_2-OUTGASSING: FIELD MEASUREMENTS OF PRECIPITATION RATES IN COMPARISON TO THEORETICAL PREDICTIONS

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中国岩溶 1992年第S1期11卷 9-24页

作者： W.Dreybrodt D.Buhmann J.Michaelis E.Usdowski University of Bremen lnstitut fur Experimentelle Physik 2800 Bremen GermanyUniversity of Bremenlnstitut fur Experimentelle Physik 2800 Bremen GermanyUniversity of Gottingen Sedimentpetrographisches Institut 3400 Gottingen GermanyUniversity of Gottingen Sedimentpetrographisches Institut 3400 Gottingen Germany

A small spring fed stream precipitates calcite by outgassing of CO2 due to chemically controlled inorganic processes. The chemical composition of the water was measured along 9 stations downstream with respect to Ca2+, Mg2+, Na+,K+, Cl-, carbonate alkalinlty, and SO42-. Temperature and pH were measured in situ. Small rectangular shaped tablets of limestone from the area were immersed into the stream for short periods and water analyses were carried out at the same time. From weight increase of the tablets, precipitation rates

关键词： carbonate limestone downstream chemically dissolution immersed tablets inorganic shaped strata

Heat Shock Factors HsfB 1 and HsfB2b Are Involved in the Regulation of Pdf1.2 Expression and Pathogen Resistance in Arabidopsis

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Molecular Plant 2009年第1期2卷 152-165页

作者： Mukesh Kumar Wolfgang Busch Hannah Birke Birgit Kemmerling Thorsten Nurnberger Friedrich Schoffl Present address: Heinrich-Pette-lnstitut Martinistrabe 52 D-20251 Hamburg Germany Max-Planck-lnstitut fur Entwicklungsbiologie Abteilung Molekularbiologie Speemannstrabe 37-39 D-72076 Tubingen Germany Universitat Tubingen Zentrum for Molekularbiologie der Pflanzen (ZMBP)--AIIgemeine Genetik Auf der Morgenstelle 28 D-72076 Tubingen Germany Universitat Tubingen Zentrum fur Molekularbiologie der Pflanzen (ZMBP)--Biochemie der Pflanzen Auf der Morgenstelle 5 D-72076 Tubingen Germany

In order to assess the functional roles of heat stress-induced class B-heat shock factors in Arabidopsis, we investigated T-DNA knockout mutants of AtHsfB1 and AtHsfB2b. Micorarray analysis of double knockout hsfB1/hsfB2b plants revealed as strong an up-regulation of the basal mRNA-levels of the defensin genes Pdfl.2a/b in mutant plants. The Pdfexpression was further enhanced by jasmonic acid treatment or infection with the necrotrophic fungus Alternaria brassicicola. The single mutant hsfB2b and the double mutant hsfB 1/B2b were significantly improved in disease resistance after A. brassicicola infection. There was no indication for a direct interaction of Hsf with the promoter of Pdf1.2, which is devoid of perfect HSE consensus Hsf-binding sequences. However, changes in the formation of late HsfA2-dependent HSE binding were detected in hsfB1/B2b plants. This suggests that HsfB1/B2b may interact with class A-Hsf in regulating the shut-off of the heat shock response. The identification of Pdfgenes as targets of Hsf-dependent negative regulation is the first evidence for an interconnection of Hsf in the regulation of biotic and abiotic responses.

关键词： Abiotic/environmental stress transcriptional control and transcription factors transcriptome analysis defense responses disease resistance Arabidopsis.

Chloroplast Proteins without Cleavable Transit Peptides： Rare Exceptions or a Major Constituent of the Chloroplast Proteome？

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Molecular Plant 2009年第6期2卷 1325-1335页

作者： Ute Armbruster Alexander Hertle Elina Makarenko Jessica Zuhlke Mathias Pribil Angela Dietzmann Ivo Schliebner Elena Aseeva Elena Fenino Michael Scharfenberg Christian Voigt Dario Leister Lehrstuhl fur Botanik Department Biologie I Ludwig-Maximilians-Universit~t MQnchen Menzinger Str. 67 D-80638 Munchen Germany

Most chloroplast proteins （cp proteins） are nucleus-encoded, synthesized on cytosolic ribosomes as precursor proteins containing a presequence （cTP）, and post-translationally imported via the Tic/Toc complex into the organelle, where the cTP is removed. Only a few unambiguous instances of cp proteins that do not require cTPs （non-canonical cp proteins） have been reported so far. However, the survey of data from large-scale proteomic studies presented here suggests that the fraction of such proteins in the total cp proteome might be as large as -30%. To explore this discrepancy, we chose a representative set of 28 putative non-canonical cp proteins, and used in vitro import and Red Fluorescent Protein （RFP）-fusion assays to determine their sub-cellular destinations. Four proteins, including embryo defective 1211, glycolate oxidase 2, protein disulfide isomerase-like protein （PDII）, and a putative glutathione S-transferase, could be unambiguously assigned to the chloroplast. Several others （＇potential cp proteins＇） were found to be imported into chloroplasts in vitro, but failed to localize to the organelle when RFP was fused to their C-terminal ends. Extrapolations suggest that the fraction of cp proteins that enter the inner compartments of the organelle, although they lack a cTP, might be as large as 11.4% of the total cp proteome. Our data also support the idea that cytosolic proteins that associate with the cp outer membrane might account for false positive cp proteins obtained in earlier studies.

关键词： Chloroplast biology mitochondria organelle biogenesis/function protein targeting.

An automated, 0.5 Hz nano-foil target positioning system for intense laser plasma experiments

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High Power Laser Science and Engineering 2017年第2期5卷 52-56页

作者： Ying Gao Jianhui Bin Daniel Haffa Christian Kreuzer Jens Hartmann Martin Speicher Florian H.Lindner Tobias M.Ostermayr Peter Hilz Thomas F.Rsch Sebastian Lehrack Franz Englbrecht Sebastian Seuferling Max Gilljohann Hao Ding Wenjun Ma Katia Parodi Jorg Schreiber Lehrstuhl fur Medizinphysik Fakultat fUr PhysikLudwig-Maximilians-Universitat MiinchenAm Coulombwall 1D-85748GarchingGermany Max-Planck-lnstitut fur Quantenoptik D-85748 GarchingGermany peking University Beijing 100871PR China

We report on a target system supporting automated positioning of nano-targets with a precision resolution of 4 μm in three dimensions. It relies on a confocal distance sensor and a microscope. The system has been commissioned to position nanometer targets with 1 Hz repetition rate. Integrating our prototype into the table-top ATLAS 300 TW-laser system at the Laboratory for Extreme Photonics in Garching, we demonstrate the operation of a 0.5 Hz laser-driven proton source with a shot-to-shot variation of the maximum energy about 27% for a level of confidence of 0.95. The reason of laser shooting experiments operated at 0.5 Hz rather than 1 Hz is because the synchronization between the nano-foil target positioning system and the laser trigger needs to improve.

关键词： high intense laser nm thick target positioning system repetition rated laser-driven ion source

Silicene on non-metallic substrates： Recent theoretical and experimental advances

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Nano Research 2018年第3期11卷 1169-1182页

作者： Emilio Scalise Kostantina Iordanidou Valeri V. Afanas'ev Andre Stesmans Michel Houssa Max-Planck-lnstitut fur Eisenforschung Max-Planck Straβe 1 D-40237 Dusseldorf Germany Department of Physics and Astronomy University of Leuven Celestijnenlaan 200D B-3001 Leuven Belgium

Silicene, the silicon counterpart of graphene, has been successfully grown on metallic substrates such as Ag（111）, ZrB2（0001）, and Ir（111） surfaces. However, characterization of its electronic structure is hampered by the metallic substrate. In addition, potential applications of silicene in nanoelectronic devices will require its growth on or integration with semiconducting and insulating substrates. We herein present a review of recent theoretical works regarding the interaction of silicene with non-metallic templates, distinguishing between the weak van-der-Waals-like interactions of silicene with, for example, layered metal （di）chalcogenides, and the stronger covalent bonding between silicene and, for example, ZnS surfaces. We then present a methodology to effectively compare the stability of diverse silicene structures using thermodynamics and molecular dynamics density functional theory calculations. Recent experimental results on the growth of silicene on MoS2 are also reported and compared to the theoretical predictions.

关键词： silicene,non-metallic substrates,chalcogenide,MoS2,layered compounds

Predicting 2D silicon allotropes on SnS2

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Nano Research 2017年第5期10卷 1697-1709页

作者： Emilio Scalise Michel Houssa Max-Planck-lnstitut fur Eisenforschung GmbH Max-Planck-StraBe 1 40237 Dusseldorf Germany Semiconductor Physics Laboratory Department of Physics and Astronomy University of Leuven Celestijnenlaan 200 D B-3001 Leuven Belgium

A first principles study on the stability and structural and electronic properties of two-dimensional silicon allotropes on a semiconducfing layered metal-chalcogenide compound, namely SnS2, is performed. The interactions between the two- dimensional silicon layer, commonly known as silicene, and the layered SnS2 template are investigated by analyzing different configurations of silicene. The calculated thermodynamic phase diagram suggests that the most stable configuration of silicene on SnS2 belongs to a family of structures with Si atoms placed on three different planes; so-called dumbbell silicene. This particular dumbbell silicene structure preserves its atomic configuration on SnS2 even at a temperature of 500 K or as a ＂flake＂ layer （i.e., a silicene cluster terminated by H atoms）, thanks to the weak interactions between the silicene and the SnS2 layers. Remarkably, an electric field can be used to tune the band gap of the silicene layer on SnS2, eventually changing its electronic behavior from semiconducting to （semi）metallic. The stability of silicene on SnS2 is very promising for the integration of silicene onto semiconducting or insulating substrates. The tunable electronic behavior of the silicene/SnS2 van der Walls heterostructure is very important not only for its use in future nanoelectronic devices, but also as a successful approach to engineering the bang-gap of layered SnS2 paving the way for the use of this layered compound in energy harvesting applications.

关键词： silicene,tin sulfide,van der Waals （vdW）heterostructure,dumbbell,chalcogenide

Tire abrasion particles negatively affect plant growth even at low concentrations and alter soil biogeochemical cycling

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Soil Ecology Letters 2022年第4期4卷 409-415页

作者： Eva F.Leifheit Hanna L.Kissener Erik Faltin Masahiro Ryo Matthias C.Rillig Freie Universitat Berlin Institut fur Biologie14195 BerlinGermany Berlin-Brandenburg Institute of Advanced Biodiversity Research 14195 BerlinGermany Leibniz Centre for Agricultural Landscape Research(ZALF) 15374 MünchebergGermany Brandenburg University of Technology Cottbus-Senftenberg 03046 CottbusGermany

Tire particles(TPs)are a major source of microplastic on land,and considering their chemical composition,they represent a potential hazard for the terrestrial environment.We studied the effectsof TPs at environmentally relevant concentrations alongawide concentrationgradient(0–160 mg g^(-1))and tested the effects on plant growth,soil pH and the key ecosystem process of litter decomposition and soil respiration.The addition of TPs negatively affected shoot and root growth already at low concentrations.Tea litter decomposition slightly increased with lower additions of TPs but decreased later on.Soil pH increased until a TP concentration of 80 mg g^(-1) and leveled off afterwards.Soil respiration clearly increased with increasing concentration of added TPs.Plant growth was likely reduced with starting contamination and stopped when contamination reached a certain level in the soil.The presence of TPs altered a number of biogeochemical soil parameters that can have further effects on plant performance.Considering the quantities of yearly produced TPs,their persistence,and toxic potential,we assume that these particles will eventually have a significant impact on terrestrial ecosystems.

关键词： Microplastic pollution Tire particles Plant growth Soil respiration Soil pH Litter decomposition