121 research outputs found

    La RSE, nouvel outil du changement organisationnel pour les entreprises marocaines : Cas des entreprises industrielles du Grand Agadir

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    Nul ne peut plus nier l’importance et la nécessité d’intégrer les pratiques et principes de la RSE dans le management contemporain. Au Maroc, de plus en plus d’entreprises adoptent cette voie de gestion ce qui nous amène à étudier l’impact de cette orientation sur le changement organisationnel. Pour y arriver, une enquête a été menée auprès de 30 sociétés anonymes industrielles basées sur le Grand Agadir. Les résultats de l’analyse renforcent lerôle des pratiques RSE sur le changement organisationnel et encouragent les entreprises à exploiter de plus en plus cette opportunité qui relève aussi bien du management social qu’organisationnel. La RSE est vue comme une opportunité qui valorise les préoccupations sociales, environnementales et économiques dans les sociétés. C’est un concept qui semble etre complexe, il varie selon la vision des dirigeants et le mode de gestion d’une société à uneautre. Elle est considérée en tant qu’une contrainte par certains dirigeants car elle nécessite plus de ressources financières alors que d’autres dirigeants l’envisagent plutôt comme un outil de valorisation de l’image de leur entreprise

    Bioaccumulation of As, Cd, Cr, Cu, Pb, Zn in Ambrosia artemisiifolia L. in the polluted area by enterprise for the production and processing of batteries

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    In this paper, the concentration of As, Cd, Cr, Cu, Pb, Zn was investigated in soil and Ambrosia artemisiifolia L. sampling from polluted cite near the enterprises for the production and processing of batteries in the city of Dnipro in Ukraine. The obtained results of the study provided to assess plants regarding bio-monitoring and phytoremediation. Although Ambrosia artemisiifolia L. is a weed that causes serious allergic reactions in humans, this species can also have a high bioaccumulative capacity regarding metals. The metals’ concentration in roots was scientifically higher than in inflorescence part. Zn and Cu had the highest concentration in Ambrosia artemisiifolia L. although lead was characterized by the highest content of available to plants forms in the soil. The distribution of As, Cd, Cr, Cu, Pb, Zn was highlighted in different parts of the plant. According to plant-up taking indexes studied elements can be ranked in the following descending order: Cu\u3eZn\u3eCr\u3eCd\u3ePb. Ambrosia artemisiifolia L. could be proposed for phytoremediation in Zn, Cu, Cd, Cr contaminated soils although this species is resistant for lead soil pollution

    The Arabidopsis pop2-1 mutant reveals the involvement of GABA transaminase in salt stress tolerance

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    <p>Abstract</p> <p>Background</p> <p>GABA (γ-aminobutyric acid) is a non protein amino acid that has been reported to accumulate in a number of plant species when subjected to high salinity and many other environmental constraints. However, no experimental data are to date available on the molecular function of GABA and the involvement of its metabolism in salt stress tolerance in higher plants. Here, we investigated the regulation of GABA metabolism in <it>Arabidopsis thaliana </it>at the metabolite, enzymatic activity and gene transcription levels upon NaCl stress.</p> <p>Results</p> <p>We identified the GABA transaminase (GABA-T), the first step of GABA catabolism, as the most responsive to NaCl. We further performed a functional analysis of the corresponding gene <it>POP2 </it>and demonstrated that the previously isolated loss-of-function <it>pop2-1 </it>mutant was oversensitive to ionic stress but not to osmotic stress suggesting a specific role in salt tolerance. NaCl oversensitivity was not associated with overaccumulation of Na<sup>+ </sup>and Cl<sup>- </sup>but mutant showed a slight decrease in K<sup>+</sup>. To bring insights into <it>POP2 </it>function, a promoter-reporter gene strategy was used and showed that <it>POP2 </it>was mainly expressed in roots under control conditions and was induced in primary root apex and aerial parts of plants in response to NaCl. Additionally, GC-MS- and UPLC-based metabolite profiling revealed major changes in roots of <it>pop2-1 </it>mutant upon NaCl stress including accumulation of amino acids and decrease in carbohydrates content.</p> <p>Conclusions</p> <p>GABA metabolism was overall up-regulated in response to NaCl in <it>Arabidopsis</it>. Particularly, GABA-T was found to play a pivotal function and impairment of this step was responsible for a decrease in salt tolerance indicating that GABA catabolism was a determinant of <it>Arabidopsis </it>salt tolerance. GABA-T would act in salt responses in linking N and C metabolisms in roots.</p

    Genome-wide interacting effects of sucrose and herbicide-mediated stress in Arabidopsis thaliana: novel insights into atrazine toxicity and sucrose-induced tolerance

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    <p>Abstract</p> <p>Background</p> <p>Soluble sugars, which play a central role in plant structure and metabolism, are also involved in the responses to a number of stresses, and act as metabolite signalling molecules that activate specific or hormone-crosstalk transduction pathways. The different roles of exogenous sucrose in the tolerance of <it>Arabidopsis thaliana </it>plantlets to the herbicide atrazine and oxidative stress were studied by a transcriptomic approach using CATMA arrays.</p> <p>Results</p> <p>Parallel situations of xenobiotic stress and sucrose-induced tolerance in the presence of atrazine, of sucrose, and of sucrose plus atrazine were compared. These approaches revealed that atrazine affected gene expression and therefore seedling physiology at a much larger scale than previously described, with potential impairment of protein translation and of reactive-oxygen-species (ROS) defence mechanisms. Correlatively, sucrose-induced protection against atrazine injury was associated with important modifications of gene expression related to ROS defence mechanisms and repair mechanisms. These protection-related changes of gene expression did not result only from the effects of sucrose itself, but from combined effects of sucrose and atrazine, thus strongly suggesting important interactions of sucrose and xenobiotic signalling or of sucrose and ROS signalling.</p> <p>Conclusion</p> <p>These interactions resulted in characteristic differential expression of gene families such as ascorbate peroxidases, glutathione-S-transferases and cytochrome P450s, and in the early induction of an original set of transcription factors. These genes used as molecular markers will eventually be of great importance in the context of xenobiotic tolerance and phytoremediation.</p

    Carbon Dynamics, Development and Stress Responses in Arabidopsis: Involvement of the APL4 Subunit of ADP-Glucose Pyrophosphorylase (Starch Synthesis)

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    An Arabidopsis thaliana T-DNA insertional mutant was identified and characterized for enhanced tolerance to the singlet-oxygen-generating herbicide atrazine in comparison to wild-type. This enhanced atrazine tolerance mutant was shown to be affected in the promoter structure and in the regulation of expression of the APL4 isoform of ADP-glucose pyrophosphorylase, a key enzyme of the starch biosynthesis pathway, thus resulting in decrease of APL4 mRNA levels. The impact of this regulatory mutation was confirmed by the analysis of an independent T-DNA insertional mutant also affected in the promoter of the APL4 gene. The resulting tissue-specific modifications of carbon partitioning in plantlets and the effects on plantlet growth and stress tolerance point out to specific and non-redundant roles of APL4 in root carbon dynamics, shoot-root relationships and sink regulations of photosynthesis. Given the effects of exogenous sugar treatments and of endogenous sugar levels on atrazine tolerance in wild-type Arabidopsis plantlets, atrazine tolerance of this apl4 mutant is discussed in terms of perception of carbon status and of investment of sugar allocation in xenobiotic and oxidative stress responses

    Cross-tolerance to abiotic stresses in halophytes: Application for phytoremediation of organic pollutants

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    International audienceHalopytes are plants able to tolerate high salt concentrations but no clear definition was retained for them. In literature, there are more studies that showed salt-enhanced tolerance to other abiotic stresses compared to investigations that found enhanced salt tolerance by other abiotic stresses in halophytes. The phenomenon by which a plant resistance to a stress induces resistance to another is referred to as cross-tolerance. In this work, we reviewed cross-tolerance in halophytes at the physiological, biochemical, and molecular levels. A special attention was accorded to the cross-tolerance between salinity and organic pollutants that could allow halophytes a higher potential of xenobiotic phytoremediation in comparison with glycophytes
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