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Accumulation of Flavonoids in an ntra ntrb Mutant Leads to Tolerance to UV-C

Molecular Plant 2009年第2期2卷 249-258页

作者： Talaat Bashandy Ludivine Taconnat jean-Pierre Renou Yves Meyer jean-Philippe Reichheld Laboratoire Genome et Developpement des Plantes Universite de Perpignan UMR CNRS 5096 52 avenue Paul Alduy 66860 Perpignan France Unite de Recherche en Genomique Vegetale 91057 Evry cedex France

NADPH-dependent thioredoxin reductases （NTRs） are key regulatory enzymes determining the redox state of thioredoxins. There are two genes encoding NTRs （NTRA and NTRB） in the Arabidopsis genome, each encoding a cytosolic and a mitochondrial isoform. A double ntra ntrb mutant has recently been characterized and shows slower plant growth, slightly wrinkled seeds and a remarkable hypersensitivity to buthionine sulfoximine （BSO）, a specific inhibitor of gluta- thione biosynthesis. In this paper, we demonstrate that this mutant also accumulates higher level of flavonoids. Analysis of transcriptome data showed that several genes of the flavonoid pathway are overexpressed in the ntra ntrb mutant. Accumulation of flavonoids is generally considered a hallmark of plant stress. Nevertheless, no elevation of the expression of genes encoding ROS-detoxification enzymes was observed, suggesting that the ntra ntrb plants do not suffer from oxidative disease. Another hypothesis suggests that flavonoids are specifically synthesized in the ntra ntrb mutant in order to rescue the inactivation of NTR. To test this, the ntra ntrb mutant was crossed with transparent testa 4 （tt4） plants with a mutation in the gene encoding the first enzyme in flavonoid biosynthesis. As ntra ntrb plants are more resistant to UV-C treatment than wild-type plants, this higher resistance was abolished in the ntra ntrb tt4 mutant, suggesting that accumulation of flavonoids in the ntra ntrb mutant protects plants against UV-light.

关键词： abiotic/environmental stress oxidative and photo-oxidative stress secondary metabolism - phenylpropanoidsand phenolics gene expression Arabidopsis.

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Wear Behavior of a Bio-inspired Bearing for off-center Loads

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Journal of Bionic Engineering 2020年第6期17卷 1251-1262页

作者： Delphine Sysaykeo jean-Marc Linares Emmanuel Mermoz Alix-Marseile Universite CNRSCentre National de la Recherche ScientifiqueISMInstitut des Sciences du MouvementMarseille 13009France Advanced concepts and Dynamic systems architecture department Airbus HelicoptersAeroport International Marseille ProvenceMarignane 13700France

Misalignment is one of the most common causes of wear in bush *** improvements have been proposed by many ***,it did not efficiently reduce the *** geometrical designs sometimes reach their *** this reason,a bio-inspired design is proposed to solve the *** this article,a bio-inspired bearing suited to misalignment was tested and compared to a classical bush *** contact pressures of both bearings were compared with static Finite Element(FE)simulations for off-center *** to the complex shape of the involved contact,the performances of both bearings were also studied over *** wear behaviors were predicted with a numerical *** methodologies emplaced to simulate the wear were described in this ***,the wear coefficient determination obtained by experimental testing was *** pressure value,the contact zone and the wear depth were compared and *** wear results for the classical bearing are in accordance with the *** simulations show a deeper wear on the classical bush bearing than on the bio-inspired *** leads to a longer period of service life for the bio-inspired bearing.

关键词： biologically inspired design bush bearing wear simulation

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Retinoid receptor-related orphan receptor alpha： a key gene setting brain circuits

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Neural Regeneration Research 2018年第5期13卷 791-794页

作者： Tania Vitalis jean Mariani PROTECT Institut National de la Santé et de la Recherche Médicale Université Paris Diderot Paris France Université Pierre et Marie Curie Sorbonne Université Paris France Centre National de la Recherche Scientifique Unité Mixte de Recherche 8256 Institut de Biologie de Paris Seine (IBPS) Biological adaptation and ageing (B2A) Team Brain Development Repair and Ageing Paris France Assistance Publique - Hopitaux de Paris Départements Hospitalo-Universitaires FAST Institut de la Longévité Ivry-Sur-Seine France

The retinoid receptor-related orphan receptor alpha（RORα） is thought to act as a constitutive activator of transcription by binding to the ROR response element（RORE） of target genes. Several mouse models in which RORα is defective have revealed the decisive roles of RORα on the development, maturation and neuroprotection of various cerebral regions including the cerebellar and somatosensory systems. We have recently shown that RORα is needed for accurate thalamic sensory system organization and somatosensory cortex development. The phenotype of various RORα deficient mice models（staggerer mutant or mouse lacking RORα in specific somatosensory regions） is, in part, reminiscent of what has been described in mice lacking thyroid hormone triiodothyronine（T3）. As in in vitro studies or in other models, our studies strongly suggest that the T3/RORα-pathway, among others, is in part responsible for the staggerer phenotype. We have indeed identified some genes that were both regulated by T3 and RORα and that are known to be implicated in the cerebellar or somatosensory system development. Moreover, several groups have shown that RORα is at the crossroad of many biological processes and pathologies, including psychiatric and degenerative disorders. In particular, defective RORα-signalling has been demonstrated in humans to be associated with the emergence of autistic-like disorders. We believe that determining the appropriate amount of RORα activity could be crucial in detecting and preventing the emergence of specific brain diseases.

关键词： cerebellum cerebral cortex development maturation neuroprotection psychiatric disorders somatosensory system

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Soil Macrofaunal Communities are Heterogeneous in Heathlands with Different Grazing Intensity

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Pedosphere 2015年第4期25卷 524-533页

作者： jean-Franois PONGE Sandrine SALMON Amélie BENOIST jean-Jacques GEOFFROY Muséum National d’Histoire Naturelle CNRS UMR 7179 4 avenue du Petit Chteau 91800 Brunoy (France) Muséum National d’Histoire Naturelle CNRS UMR 7204 4 avenue du Petit Chteau 91800 Brunoy (France)

Moderate grazing by cattle increases the heterogeneity of soil and vegetation. This has been suggested as an ecologically sustainable mean of managing natural environments endangered by tree encroachment, such as heathlands. Our study was performed to test the impact of grazing intensity on soil macroinvertebrate communities in heterogeneous landscapes in a private property eligible to the Natura 2000 European Network of Special Protection Areas within the Brenne Natural Regional Park （Indre, ~rance）. We sampled macroinvertebrates along a broken line crossing 5 different land-use types, from pasture to pine forest, passing through a besom heath （Erica scoparia） heathland at 3 levels of cattle pressure. We hypothesized that： i） litter-dwelling （mostly arthropods and mollusks） and soil-dwelling macroinvertebrates （mostly earthworms） would respond in an opposite manner to various grazing intensities, and ii） intermediate cattle pressure （pastured heath） would increase soil and community heterogeneity. The results supported the first hypothesis, which was explained by land-use impacts mediated by soil properties. However, our results supported only partly the second hypothesis since maximum dissimilarity （whether in the composition of soil macroinvertebrate communities or in soil features） was observed in only one out of the two pastured heaths where cattle pressure was intermediate.

关键词： besom heath cattle grazing heterogeneity land-use types soil macroinvertebrates

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Water Losses in Arid and Semi-Arid Zone:Evaporation, Evapotranspiration and Seepage

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Journal of Mountain Science 2012年第2期9卷 256-261页

作者： MUPENZI jean de la Paix LI Lanhai GE Jiwen NGAMIJE jean ACHAL Verenyam HABIYAREMYE Gabriel HABUMUGISHA jean de Dieu State Key laboratory of Desert and Oasis Ecology Xinfiang Institute of Ecologg and Geography Chinese Academy of Sciences 818 Beijing road south Urumqi Xinjiang 830011 China China University ofGeosciences （Wuhan） 388 Lumo Road Wuhan 430074 Hubei China Independent Institute of Lay Adventists ofKigali （INILAK） P O Box 6392 Kigali-Rwanda Institut Polytechnique de Byumba （IPB） PO Box 25 Byumba Rwanda

The primary purpose of this study was to assess water losses by evapotranspiration, evaporation and seepage in arid ***, evaporation and seepage are the main causes of water *** modeling water losses,a combination of Genetic Programming(GP),Penman-Monteith(PM) and Penman combination model for measurement of evapotranspiration,evaporation and seepage has been *** results were found to be varying depending on how the evaporation and seepage phenomena are *** results show that that there is an improvement in reducing evapotranspiration,evaporation and seepage losses in arid and semi-arid region.

关键词： Arid zone Evaporation Evapotranspiration Seepage Water losses China

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Differences in egg hatching time between cyclical and obligate parthenogenetic lineages of aphids

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Insect Science 2019年第1期26卷 135-141页

作者： Charles-Antoine Dedryver Joel Bonhomme jean-Francois Le Gallic jean-Christophe Simon Unite Mixte de Recherche IGEPP 1349 INRAIAgrocampus OuestlUniversite Rennes 1Le Rheu cedexFrance

Many aphid species exhibit a variation in reproductive mode which is influenced by winter climate regimes,with cyclical parthenogenetic (CP)lines dominating in cold winter areas (because they produce cold-resistant eggs)and obligate parthenogenetic (OP) ones in mild winter regions (because of their parthenogenetic overwintering).Genetic studies on several aphid species have shown that the OP trait can be transmitted during sexual events involving the 2 types of *** genetic system could be considered as a local safeguarding mechanism for OP alleles in case severe frost would have killed all parthenogenetically overwintering ***,this strategy would only be efficient in restoring local polymorphism in breeding systems if the newly hatched OP recombinants remain competitive over their CP *** this study we compared egg hatching sequences of CP and OP F1 clones from several crosses obtained for 2 cereal aphid species,Sitobion avenae (constant 5℃,8 h of light)and Rhopalosiphum padi (winter outdoor conditions).For ***,we obtained F1 offspring from 6 crosses, involving 4 clones while in *** F1 were obtained from 11 crosses involving 14 clones. We showed that in both species proportions of OP clones were higher in the first half of the progeny relative to the second *** addition,F1 OP clones hatched in the mean about a week earlier than their CP sibs,which gives them a demographic advantage at the start of the growth *** then discussed the consequences of this fitness advantage for the maintenance and spread of the OP trait in aphid populations.

关键词： asexuality diapauses genetic variation insects overwintering strategies reproductive mode

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A Pivotal Role of DELLAs in Regulating Multiple Hormone Signals

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Molecular Plant 2016年第1期9卷 10-20页

作者： jean-Michel Daviere Patrick Achard Institut de Biologie Moleculaire des Plantes (IBMP) UPR2357 associe avec l'Universite de Strasbourg 12 rue General Zimmer 67084 Strasbourg Cedex France

Plant phenotypic plasticity is controlled by diverse hormone pathways, which integrate and convey infor- mation from multiple developmental and environmental signals. Moreover, in plants many processes such as growth, development, and defense are regulated in similar ways by multiple hormones. Among them, gibberellins （GAs） are phytohormones with pleiotropic actions, regulating various growth processes throughout the plant life cycle. Previous work has revealed extensive interplay between GAs and other hor- mones, but the molecular mechanism became apparent only recently. Molecular and physiological studies have demonstrated that DELLA proteins, considered as master negative regulators of GA signaling, inte- grate multiple hormone signaling pathways through physical interactions with transcription factors or reg- ulatory proteins from different families. In this review, we summarize the latest progress in GA signaling and its direct crosstalk with the main phytohormone signaling, emphasizing the multifaceted role of DELLA proteins with key components of major hormone signaling pathways.

关键词： gibberellins DELLAs hormone crosstalk plant development phenotypic plasticity

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Stagnant lids and mantle overturns:Implications for Archaean tectonics, magmagenesis,crustal growth, mantle evolution, and the start of plate tectonics

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Geoscience Frontiers 2018年第1期9卷 19-49页

作者： jean H.Bédard Geological Survey of Canada GSC-Québec

The lower plate is the dominant agent in modern convergent margins characterized by active subduction,as negatively buoyant oceanic lithosphere sinks into the asthenosphere under its own *** is a strong plate-driving force because the slab-pull force is transmitted through the stiff sub-oceanic lithospheric *** geological and geochemical data seem inconsistent with the existence of modernstyle ridges and arcs in the Archaean,a periodically-destabilized stagnant-lid crust system is proposed ***-lid intervals may correspond to periods of layered mantle convection where efficient cooling was restricted to the upper mantle,perturbing Earth's heat generation/loss balance,eventually triggering mantle *** basalts were derived from fertile mantle in overturn upwelling zones(OUZOs),which were larger and longer-lived than post-Archaean *** cratons/continents probably formed above OUZOs as large volumes of basalt and komatiite were delivered for protracted periods,allowing basal crustal cannibalism,garnetiferous crustal restite delamination,and coupled development of continental crust and sub-continental lithospheric *** mixing and rehomogenization during overturns retarded development of isotopically depleted MORB(mid-ocean ridge basalt)*** after the start of true subduction did sequestration of subducted slabs at the coremantle boundary lead to the development of the depleted MORB mantle *** Archaean mantle overturns,pre-existing continents located above OUZOs would be strongly reworked;whereas OUZOdistal continents would drift in response to mantle *** leading edge of drifting Archaean continents would be convergent margins characterized by terrane accretion,imbrication,subcretion and anatexis of unsubductable oceanic *** Earth cooled and the background oceanic lithosphere became denser and stiffer,there would be an increasing probability that oceanic crustal segments could

关键词： Archaean Mantle-overturn Stagnant-lid Continental crust Oceanic crust Subcretion

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Subdifferentials of Distance Functions,Approximations and Enlargements

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Acta Mathematica Sinica,English Series 2007年第3期23卷 507-520页

作者： jean-Paul PENOT Robert RATSIMAHALO Department of Mathematics Faculty of Sciencesav.de l'Université BP 115564013 PA U CédexFrance Business Unit:Bank and Financials SODIFRANCE104 rue Castagnary75015 ParisFrance

In this work, we study some subdifferentials of the distance function to a nonempty nonconvex closed subset of a general Banach space. We relate them to the normal cone of the enlargements of the set which can be cons... 详细信息

关键词： Distance function Normal cone Regularization Subdifferential

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Regulation of Sulfate Uptake and Assimilation——the Same or Not the Same？

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Molecular Plant 2010年第2期3卷 314-325页

作者： jean-Claude Davidian Stanislav Kopriva Unite mixte de recherche Biochimie et Physiologie Molculaire des Plantes Montpellier SupAgro/CNRS/INRA/UM2 2 place Pierre Viala 34060 MontpellierCedex 2 France Department of Metabolic Biology John Innes Centre Norwich NR4 7UH UK

Plant take up the essential nutrient sulfur as sulfate from the soil, reduce it, and assimilate into bioorganic compounds, with cysteine being the first product. Both sulfate uptake and assimilation are highly regulated by the demand for the reduced sulfur, by availability of nutrients, and by environmental conditions. In the last decade, great prog- ress has been achieved in dissecting the regulation of sulfur metabolism. Sulfate uptake and reduction of activated sulfate, adenosine 5＇-phosphosulfate （APS）, to sulfite by APS reductase appear to be the key regulatory steps. Here, we review the current knowledge on regulation of these processes, with special attention given to similarities and differences.

关键词： Metabolic regulation nutrient and metal transport nutrition primary metabolism sulfate uptake sulfur metabolism.

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