INRA-URLEG,Génétique et Amélioration des plantes,Domaine d’Epoisses,21110 Bretenieres,FranceMini-biographyKarine Gallardo is a research scientist working on seed development and quality within the INRA Research Unit 102 Genetics and Ecophysiology of Grain Legumes. She is a member of two French networks called the Green Proteome and the French Society of Electrophoresis and Proteomics. K. Gallardo studied seed biology at the CNRS/Bayer CropScience Joint laboratory UMR2847 where she earned her doctorate in 2001, working on the molecular mechanisms associated with seed germination and priming (European project FAIR5-CT97-3711). Following a one-year post-doctorate within the UR102-INRA where she became interested in the biology of legume seed development, she moved to the University of Davis to learn advances in the TILLING technology. In 2002, she was appointed to the UR102-INRA. The current focus of the research of K. Gallardo concerns the molecular mechanisms involved in legume seed formation, with a particular emphasis on sulphur transport and metabolism.
Integrated transcriptomics and proteomics analysis of M. truncatula seed development towards enhancing the sulphur content of grain legume crops.Karine Gallardo
1, Christian Firnhaber
2, Jérôme Verdier
1, Hélène Zuber
1, Delphine Hericher
1, Maya Belghazi
3, Christine Le Signor
1, Michael Udvardi
4, Helge Küster
2, and Richard Thompson
11INRA, UR102 Genetics and Ecophysiology of Grain legumes, F-21000 Dijon
2Genomics of Legume Plants, Institute for Genome Research and Systems Biology, Center for Biotechnology, Bielefeld University, D-33594 Bielefeld, Germany
3INRA, UMR6175, Mass Spectrometry Platform for Proteomics, F-37380 Nouzilly
4Max Planck Institute of Molecular Plant Physiology, Germany (M.U.)
gallardo@epoisses.inra.frAn approach combining proteomics with a transcriptome study based on the use of the most comprehensive legume oligonucleotide microarray currently available, Mt16kOLI1, has been pursued to specify the networks of gene expression during Medicago truncatula seed development. By comparing protein and transcript levels, a number of genes can be classified according to their mode of regulation. In most cases, changes in transcript and protein abundance were parallel, but divergent expression patterns occurred suggesting a significant degree of post-transcriptional control. In order to further characterize the individual expression patterns of the genes and proteins identified, their distribution was examined in the isolated seed tissues, namely seed coat, endosperm and embryo. A remarkable compartmentalization of enzymes involved in methionine biosynthesis between these tissues was revealed that may regulate the availability of sulphur-containing amino acids during seed filling. This inter-tissue compartmentalization, which was also apparent for enzymes of sulphur assimilation and tryptophan synthesis, is relevant to strategies for modifying the nutritional value of legume seeds. The data also revealed the sites of expression within the seed of a large number of transporters implied in nutrient import and intra-seed translocations, of which several were preferentially expressed in seeds compared to other plant organs. Mutant alleles for these genes, and additional genes identified in parallel using a high-throughput transcription factor profiling platform based in quantitative real-time RT-PCR (Coll. M. Udvardi), are being screened by TILLING (Targeting Induced Local Lesions In Genomes). Future steps will be discussed in view of exploiting these findings to improve the nutritional value of grain legume crops low in the essential sulphur-rich amino acids.
