1H-NMR metabolomics: Profiling method for a rapid and efficient screening of transgenic plants

Metabolomics-based approaches are methods of choice for studying changes in fruit composition induced by  environmental or genetic modulation of biochemical pathways in the fruit. Owing to enzyme redundancy and  high plasticity of the metabolic network, transgenic alteration of the activity of the enzymes from the central metabolism very often results in only slight modifications of the fruit composition. In order to avoid costly and  time-consuming plant analysis, we used a fast and sensitive 1H-NMR-based metabolomic profiling technique  allowing discovery of slight metabolite variations in a large number of samples. Here, we describe the  screening of transgenic tomato plants in which two genes from the central metabolism, phosphoenolpyruvate  carboxylase (EC.3.4.1.1) and malate synthase (EC 2.3.3.9) were silenced by antisens and RNAi strategy.  1H-NMR metabolomic profiles of methanol-d4 D2O buffer extracts of tomato fruit flesh were acquired and  subjected to unsupervised multivariate statistical analysis. 1H-NMR spectra were binned into variable-size  spectral domains, making it possible to get an overall analysis of a large number of resonances, even in the  case of uncontrolled variation of the chemical shift. Principal component analysis was used to separate groups  of samples and to relate known and unknown metabolites to transgenic events. The screening of 100 samples,  from extraction to data mining, took 36 h. Thus, this procedure allows the rapid selection of metabolic  phenotypes of interest among about 30 transgenic lines.Key words: Metabolome, GMO, tomato, fruit, 1H-NMR profiling, screening

Regulation of the Fruit-Specific PEP Carboxylase SlPPC2 Promoter at Early Stages of Tomato Fruit Development

The SlPPC2 phosphoenolpyruvate carboxylase (PEPC; EC 4.1.1.31) gene from tomato (Solanum lycopersicum) is differentially and specifically expressed in expanding tissues of developing tomato fruit. We recently showed that a 1966 bp DNA fragment located upstream of the ATG codon of the SlPPC2 gene (GenBank AJ313434) confers appropriate fruit-specificity in transgenic tomato. In this study, we further investigated the regulation of the SlPPC2 promoter gene by analysing the SlPPC2 cis-regulating region fused to either the firefly luciferase (LUC) or the β-glucuronidase (GUS) reporter gene, using stable genetic transformation and biolistic transient expression assays in the fruit. Biolistic analyses of 5′ SlPPC2 promoter deletions fused to LUC in fruits at the 8th day after anthesis revealed that positive regulatory regions are mostly located in the distal region of the promoter. In addition, a 5′ UTR leader intron present in the 1966 bp fragment contributes to the proper temporal regulation of LUC activity during fruit development. Interestingly, the SlPPC2 promoter responds to hormones (ethylene) and metabolites (sugars) regulating fruit growth and metabolism. When tested by transient expression assays, the chimeric promoter:LUC fusion constructs allowed gene expression in both fruit and leaf, suggesting that integration into the chromatin is required for fruit-specificity. These results clearly demonstrate that SlPPC2 gene is under tight transcriptional regulation in the developing fruit and that its promoter can be employed to drive transgene expression specifically during the cell expansion stage of tomato fruit. Taken together, the SlPPC2 promoter offers great potential as a candidate for driving transgene expression specifically in developing tomato fruit from various tomato cultivars

Etude de certains aspects du metabolisme des nucleotides au cours du developpement de souches sauvage et mutantes vestigial chez Drosophila melanogaster

SIGLET 55668 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Etude de certains aspects de la resistance a l'aminopterine au cours du developpement de la drosophile

SIGLEINIST T 74133 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Obtencion y caracterizacion preliminar de plantas de tomate (Lycopersicon esculentum) transformadas con genes de capside de diferentes potyvirus

* INRA, Documentation, Domaine St Paul, Site Agroparc, 84914 Avignon cedex 9 Diffusion du document : INRA, Documentation, Domaine St Paul, Site Agroparc, 84914 Avignon cedex 9International audienc

Interaction between a threatened endemic plant (Anchusa crispa) and the invasive Argentine ant (Linepithema humile)

International audienc

Gène de résistance à <em>Aphis gossypii</em>

La présente invention est relative au clonage du gène Vat intervenant dans la résistance au puceron Aphis gossypii et/ou à la transmission virale par ledit puceron, ainsi qu'à l'identification de nouveaux marqueurs de ce gène

Gène de résistance à <em>Aphis gossypii</em>

La présente invention est relative au clonage du gène Vat intervenant dans la résistance au puceron Aphis gossypii et/ou à la transmission virale par ledit puceron, ainsi qu'à l'identification de nouveaux marqueurs de ce gène

Modification of photosynthetic regulation in tomato overexpressing glutathione peroxidase

To investigate the function of glutathione peroxidase (GPX) in plants, we produced transgenic tomato plants overexpressing an eukaryotic selenium-independent GPX (GPX5). We show here that total GPX activity was increased by 50% in transgenic plants, when compared to control plants transformed with the binary vector without the insert (PZP111). A preliminary two-dimensional electrophoretic protein analysis of the GPX overexpressing plants showed notably a decrease in the accumulation of proteins identified as rubisco small subunit I and fructose-1,6-bisphosphate aldolase, two proteins involved in photosynthesis. These observations, together with the fact that in standard culture conditions, GPX-overexpressing plants were not phenotypically distinct from control plants prompted us to challenge the plants with a chilling treatment that is known to affect photosynthesis activity. We found that upon chilling treatment with low light level, photosynthesis was not affected in GPX-overexpressing plants while it was in control plants, as revealed by chlorophyll fluorescence parameters and fructose-1,6-biphosphatase activity. These results suggest that overexpression of a selenium-independent GPX in tomato plants modifies specifically gene expression and leads to modifications of photosynthetic regulation processes

Map-based cloning of the Vat gene from melon conferring resistance to both aphid colonization and aphid transmission of several viruses

Événement(s) lié(s) : - Cucurbitaceae 2004; Olomouc (CZE) - (2004-07-12 - 2004-07-17)International audienc