Campus University des Cezeaux


Campus University des Cezeaux

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Tamasloukht B.,CNRS Plant Research Laboratory | Wong Quai Lam M.S.-J.,CNRS Plant Research Laboratory | Martinez Y.,CNRS Plant Research Laboratory | Tozo K.,CNRS Plant Research Laboratory | And 13 more authors.
Journal of Experimental Botany | Year: 2011

Cinnamoyl-CoA reductase (CCR), which catalyses the first committed step of the lignin-specific branch of monolignol biosynthesis, has been extensively characterized in dicot species, but few data are available in monocots. By screening a Mu insertional mutant collection in maize, a mutant in the CCR1 gene was isolated named Zmccr1 -. In this mutant, CCR1 gene expression is reduced to 31% of the residual wild-type level. Zmccr1 - exhibited enhanced digestibility without compromising plant growth and development. Lignin analysis revealed a slight decrease in lignin content and significant changes in lignin structure. p-Hydroxyphenyl units were strongly decreased and the syringyl/guaiacyl ratio was slightly increased. At the cellular level, alterations in lignin deposition were mainly observed in the walls of the sclerenchymatic fibre cells surrounding the vascular bundles. These cell walls showed little to no staining with phloroglucinol. These histochemical changes were accompanied by an increase in sclerenchyma surface area and an alteration in cell shape. In keeping with this cell type-specific phenotype, transcriptomics performed at an early stage of plant development revealed the down-regulation of genes specifically associated with fibre wall formation. To the present authors' knowledge, this is the first functional characterization of CCR1 in a grass species. © 2011 The Author(s).

Memiaghe S.,CNRS Laboratory of Electric Arc and Thermal Plasmas | Memiaghe S.,A.P.S. University | Bussiere W.,CNRS Laboratory of Electric Arc and Thermal Plasmas | Bussiere W.,A.P.S. University | And 6 more authors.
High Temperature Material Processes | Year: 2010

This work deals with the comparison between calculations and measurements of pre-arcing times in High Breaking Capacity fuses under typical fault current conditions. This paper also describes the temperature evolution and the Joule energy dissipated in a fuse element during the pre-arcing time. By varying typical electrical parameters, namely the closing angle and the power factor, we show that various prospective currents such as those observed in industrial case can be fairly simulated. The pre-arcing time and then the clearing of the fault current are shown to be deeply dependent on these electrical characteristics. We exhibit simulated results of prospective current and supply voltage waves for given closing angles under two typical power factors which are compared with the experimental ones. A comparison between simulated pre-arcing times with experimental ones shows some discrepancies and a discussion on the numerical assumptions is made.

Sta C.,University Blaise Pascal | Sta C.,University of Carthage | Sta C.,Campus University des Cezeaux | Ledoigt G.,University Blaise Pascal | And 4 more authors.
Pesticide Biochemistry and Physiology | Year: 2012

Potential genotoxicity of sulcotrione 2-(2-chloro-4-(methylsulfonyl)benzoyl)-1,3-cyclohexanedione, a selective triketonic herbicide was evaluated on Vicia faba seedlings in hydroponic culture conditions. Sulcotrione (10 -5, 10 -4 and 2×10 -4M) treatments for 45h, caused a dose dependent increase in micronuclei frequencies in root meristematic cells. Cytological analysis of root tips cells showed aneugenic effects of the sulcotrione on the plant root meristems. Sulcotrione induced chromosomal alterations at the lowest concentration used (10 -5M) when incubated for 42h, indicating the potent mutagenic effect of this element. This is the first report for the genotoxicity of such a sulcotrione herbicide. © 2012 Elsevier Inc.

Sta C.,University Blaise Pascal | Sta C.,Campus University des Cezeaux | Sta C.,University of Carthage | Goujon E.,University Blaise Pascal | And 4 more authors.
Journal of Agricultural and Food Chemistry | Year: 2014

The cell toxicity of sulcotrione, a selective triketone herbicide, was evaluated on Vicia faba. Sulcotrione, trademark Mikado, grape marc, and mixtures of sulcotrione or Mikado with grape marc induced cell death. Addition of grape marc to either sulcotrione or Mikado enhanced cell death, especially with Mikado. Addition of grape marc to herbicides, sulcotrione, or Mikado resulted in different expression of genes usually associated with cell stress. Mixtures of grape marc and herbicides enhanced transcript accumulation for ubiquitin, hsp 70, and cytosolic superoxide dismutase, but did not change ascorbate peroxidase transcript accumulation. The results thus provide evidence that sulcotrione, Mikado, and mixtures with grape marc can trigger cell death and specific gene expressions. Cocktails of products with sulcotrione, such as commercial additives and grape marc, can modify biological features of pesticide. Moreover, grape marc differently enhanced cell toxicity of sulcotrione and Mikado, suggesting a synergy between pesticide products and grape marc. © 2014 American Chemical Society.

PubMed | Campus University des Cezeaux
Type: Journal Article | Journal: Plant cell reports | Year: 2013

A reliable protocol for the transformation of cultivated sunflower (Helianthus annuus L.) has been established, based on microprojectile bombardment of half shoot apices in combination with Agrobacterium tumefaciens coculture. Transgenic shoots have been obtained from 5 inbred lines, although transformation efficiencies varied with the genotype. Plants expressing the transgenes could be recovered from up to 7% of the explants. A minority of plants was shown to be chimaeric for expression of -glucuronidase activity while most appeared to be uniformly transformed. Genetic segregation was 31 for both -glucuronidase and neomycine phospho transferase in some plants, indicating that the respective mother plants were uniformly transformed. Integration of the foreign genes was also shown by Southern analysis.

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