Contacts :

Group leader Loïc Lepiniec Senior Scientist Christian Dubos Research Scientist Sébastien Baud Research Scientist CNRS Martine Miquel Research Scientist CNRS Nathalie Berger Engineer Johanne Thevenin Technician Zsolt Kelemen Engineer Contract from 01/08/ 11 to 31/07/12 Sophie Bobet Master 2 from 3/01/12 to 29/06/12 Rkia Boudaoud Master 2 from 1/03/12 to 30/08/12

Michel Caboche Senior Scientist Bertrand Dubreucq Research Scientist Alexandra To Engineer Damaris Grain Technician Guillaume Barthole PhD student from 01/09/10 to31/08/13   Wenjia Xu PhD student from 03/09/10 to 31/08/13 Manon Payre Licence 3 Pro from 05/09/11 to 14/09/12 Chloé Marchive Post-Doc Project ANR-SOLAR from 02/11/11 to 30/10/14

From biological, agronomical, nutritional or industrial viewpoints the qualities of seeds are determined by the structure and quantity of various macromolecules stored in different seed tissues, namely the integuments, endosperm and embryo. Our goal is to characterize important functions and actors (i.e. genes and proteins) and the molecular mechanisms involved in the control of seed development. The main current projects focus on Arabidopsis seed maturation, oil biosynthesis and storage, and flavonoid metabolism (mainly in the integuments). A specific attention is paid to transcriptional regulations that have been shown to play key roles in seed development and provide interesting clues and tools for improving seed qualities.

Seeds have played a critical role in the evolution and dispersion of higher plants on earth. They allow most of the higher plants to cope with unfavourable environmental conditions by interrupting their life cycle and resuming growth when placed again under favourable conditions. Seeds have also some roles of the utmost importance for the human kind. First, they constitute the main vector for the improvement of agronomic practices and the management of genetic resources, two key factors for the development of sustainable agriculture and the preservation of biodiversity. Then, seeds are (directly or indirectly) the main source for human nutrition. Last, nowadays, seed storage compounds constitute a sustainable alternative to fossil carbon for chemical industry. For agronomic, nutritional or industrial purposes, it would be interesting to produce seeds that accumulate higher content of specific compounds/molecules (e.g. specific fatty acids, sugars, amino acids, vitamins, secondary metabolites) that are stored in various tissues (integuments, endosperm or embryo).

Although the main metabolic pathways involved in the synthesis of oils, starch, proteins or flavonoids are relatively well characterized, the regulation and distribution of fluxes between these pathways are not yet well understood. Similarly, the molecular and cellular mechanisms involved in the biogenesis of reserve organelles (oil and protein bodies) or flavonoid transport, modifications, and storage, remain poorly understood. Considerind that this knowledge may provide us with new molecular tools for the improvement of seed quality of crops, the understanding of the genetic and physiological controls of seed development and maturation constitutes a key area of research.

Tremendous progresses have been obtained during the last years working with crops species. Nevertheless, Arabidopsis thaliana remains a model plant of choice for studying seed biology, facilitating the basic research, and for drawing a comprehensive scheme of seed development and maturation. Extensive tools available for the genetic and molecular dissection of development and metabolism together with analytical and cytological procedures adapted to very small seeds have led to a good description of the biochemical pathways producing storage compounds.

We carry out the functional analyses of enzymes, carriers or structural proteins involved in the metabolism and storage of fatty acids and oils (e.g. ACC1, PKp, BCCP, Oleosins or HSD1) or flavonoids (e.g. TT10, TT12, and TT15). We characterize their activities, spatio-temporal expression, and intracellular localization. The expression of corresponding genes requires a complex and robust coordination by developmental and physiological signals provided by different networks of transcription factors. We work mainly on the AFL network (i.e. ABI3-FUSCA3-LEC2) that controls embryo development and maturation and on the TT (TRANSPARENT TESTA) network (i.e. TT2-TT8-TTG1 complex, and TT1, TT16, or TTG2) that controls proanthocyanidin accumulation in the integuments. This level of regulation seems particularly interesting from both a cognitive point of view and for its potential applications. A set of specific tools and experiments is developed in planta, in yeast, and in vitro for the functional analyses of transcription factors. Ultimately, a comprehensive description of the molecular and physiological controls of seed development and maturation will allow building predictive models, providing molecular markers and tools for improving seed quality of crops.

Baud S, Feria Bourrellier AB, Azzopardi M, Berger A, Dechorgnat J, Daniel-Vedele F, Lepiniec L, Miquel M, Rochat C, Hodges M, Ferrario-Méry S. (2010) PII is induced by WRINKLED1 and fine-tunes fatty acid composition in seeds of Arabidopsis thaliana. Plant J. 64(2):291-303.

Harscoët E, Dubreucq B, Palauqui JC, Lepiniec L. (2010) PLoS One. 2010 Sep 20;5(9):e12829.

Dubos C, Stracke R, Grotewold E, Weisshaar B, Martin C, Lepiniec L. (2010) MYB transcription factors in Arabidopsis. Trends Plant Sci. 2010 Oct;15(10):573-81.

North H, Baud S, Debeaujon I, Dubos C, Dubreucq B, Grappin P, Jullien M, Lepiniec L, Marion-Poll A, Miquel M, Rajjou L, Routaboul JM, Caboche M. (2010) Arabidopsis seed secrets unravelled after a decade of genetic and omics-driven research. Plant J. 2010 Mar;61(6):971-81.

Baud S, Lepiniec L. (2010) Physiological and developmental regulation of seed oil production. Prog Lipid Res. 2010 Jul;49(3):235-49.

Rajjou L, Debeaujon I (2008) Seed longevity: Survival and maintenance of high germination ability of dry seeds. CR Biologies (in press) DOI

Dubos C, Le Gourrierec J, Baudry A, Huep G, Lanet E, Debeaujon I, Routaboul J-M, Alboresi A, Weisshaar B, Lepiniec L (2008) MYBL2 is a new regulator of flavonoid biosynthesis in Arabidopsis thaliana. The Plant Journal (PubMed)

Luceri C, Giovannelli L, Pitozzi V, Toti S, Castagnini C, Routaboul JM, Lepiniec L, Larrosa M, Dolara P. (2008) Liver and Colon DNA oxidative damage and gene expression profiles of rats fed Arabidopsis thaliana mutants seed containing contrasted flavonoid contents, Food Chem Toxicol. 46, 1213-1220 (PubMed)

Marinova K, Pourcel L, Weder B, Schwarz M, Barron D, Routaboul JM, Debeaujon I, Klein M. (2007) The Arabidopsis MATE transporter TT12 acts as a vacuolar flavonoid/H+ -antiporter active in proanthocyanidin-accumulating cells of the seed coat. Plant Cell. 19, 2023-2038 (PubMed)

Baud S, Lepiniec L (2008) Compared analysis of the regulatory systems controlling lipogenesis in hepatocytes of mice and in maturing oilseeds of Arabidopsis. C. R. Biologies, 331, 737-745 DOI

Purkrtova Z, Jolivet P, Miquel M, Chardot T (2008) Structure and function of seed lipid body-associated proteins. C. R. Biologies, 331, 746-754 DOI

Angeles Nunez JG, Kronenberger J, Wuillème S, Lepiniec L, Rochat C (2008) Study of AtSUS2 localization in seeds reveals a strong association with plastids. Plant Cell Physiol. 49, 1621-1626

Bach L, Michaelson LV, Haslam R, Bellec Y, Gissot L, Marion J, Da Costa M, Boutin JP, Miquel M, Tellier F, Domergue F, Markham J, Beaudoin F, Napier J, Faure JD (2008) The plant very long chain hydroxy fatty Acyl-CoA dehydratase PASTICCINO2 is essential and limiting for plant development. Proc. Natl Acad. Sci. U.S.A. 105, 14727-14731

Santos-Mendoza M, Dubreucq B, Baud S, Parcy F, Caboche M, Lepiniec L. (2008) Deciphering gene regulatory networks that control seed development and maturation in Arabidopsis. Plant J. 54, 608-20 (PubMed)

Truernit E, Bauby H, Dubreucq B, Grandjean O, Runions J, Barthélémy J, Palauqui JC. (2008) High-resolution whole-mount imaging of three-dimensional tissue organization and gene expression enables the study of Phloem development and structure in Arabidopsis. Plant Cell 20,1494-503 (PubMed)

Pourcel L, Routaboul JM, Cheynier V, Lepiniec L, Debeaujon I. (2007) Flavonoid oxidation in plants: from biochemical properties to physiological functions. Trends Plant Sci. 12, 29-36 (PubMed)

Baud S, Mendoza MS, To A, Harscoët E, Lepiniec L, Dubreucq B. (2007a) WRINKLED1 specifies the regulatory action of LEAFY COTYLEDON2 towards fatty acid metabolism during seed maturation in Arabidopsis. Plant J. 50, 825-838. (PubMed)

Baud S, Wuillème S, Dubreucq B, de Almeida A, Vuagnat C, Lepiniec L, Miquel M, Rochat C. (2007b) Function of plastidial pyruvate kinases in seeds of Arabidopsis thaliana. Plant J. 52, 405-419. (PubMed)

d'Andréa S, Canonge M, Beopoulos A, Jolivet P, Hartmann MA, Miquel M, Lepiniec L, Chardot T. (2007) At5g50600 encodes a member of the short-chain dehydrogenase reductase superfamily with 11beta- and 17beta-hydroxysteroid dehydrogenase activities associated with Arabidopsis thaliana seed oil bodies. Biochimie 89, 222-229. (PubMed)

Kerhoas L, Aouak D, Cingöz A, Birlirakis N, Routaboul JM, Lepiniec L, Einhorn J (2006) Structural characterization of the major flavonoid glycosides from Arabidopsis thaliana seeds, Agric. Food. Biochem. 54, 6603-12 (PubMed)

Baudry A, Caboche M, Lepiniec L (2006) TT8 controls its own expression in a feedback regulation involving TTG1 and homologous MYB and bHLH factors, allowing a strong and cell-specific accumulation of flavonoids in Arabidopsis thaliana. Plant J, 46, 768-779 (PubMed)

Lepiniec L, Debeaujon I, Routaboul JM, Baudry A, Pourcel L, Nesi N, Caboche M (2006) Genetics and Biochemistry of Seed Flavonoids. Annu Rev Plant Biol 57, 405-430 (PubMed)

Routaboul JM, Kerhoas L, Debeaujon I, Pourcel L, Caboche M, Einhorn J, Lepiniec L (2006) Flavonoid diversity and biosynthesis in seed of Arabidopsis thaliana. Planta, 224, 96-107 (PubMed)

Pourcel L, Routaboul JM, Kerhoas L, Caboche M, Lepiniec L and Debeaujon I (2005) TRANSPARENT TESTA10 encodes a laccase-like enzyme involved in oxidative polymerization of flavonoids in Arabidopsis seed coat. Plant Cell, 17, 2966-2980 (PubMed)

Baud S, Wuilleme S, Lemoine R, Kronenberger J, Caboche M, Lepiniec L, Rochat C (2005) The AtSUC5 sucrose transporter specifically expressed in the endosperm is involved in early seed development in Arabidopsis. Plant J 43, 824-836. (PubMed)

Djemel N, Guedon D, Lechevalier A, Salon C, Miquel M, Prosperi J, Rochat C, Boutin JP (2005) Development and composition of the seeds of 9 genotypes of the Medicago truncatula species complex. Plant Physiol Biochem 43, 557-566. (PubMed)

Santos Mendoza M, Dubreucq B, Miquel M, Caboche M, Lepiniec L (2005) LEAFY COTYLEDON 2 activation is sufficient to trigger the accumulation of oil and seed specific mRNAs in Arabidopsis leaves. FEBS 579, 4666-4670. (PubMed)

Baud S, Bellec Y, Miquel M, Bellini C, Caboche M, Lepiniec L, Faure JD, Rochat C (2004) Gurke and Pasticcino3 mutants affected in embryo development are impaired in acetyl-CoA carboxylase. EMBO Reports 5, 515-520. (PubMed)

Baud S, Vaultier MN, Rochat C (2004) Structure and expression profile of the sucrose synthase multigene family in Arabidopsis. J Exp Bot 55, 397-409. (PubMed)

Baudry A, Heim MA, Dubreucq B, Caboche M, Weisshaar B, Lepiniec L (2004) TT2, TT8, and TTG1 synergistically specify the expression of BANYULS and proanthocyanidin biosynthesis in Arabidopsis thaliana. Plant J., 39, 366-380. (PubMed)

Debeaujon I., N. Nesi, P.Perez, M. Devic, O. Grandjean, M. Caboche, and Lepiniec L (2003) Proanthocyanidin-Accumulating Cells in Arabidopsis Testa: Regulation of Differentiation and Role in Seed Development. Plant Cell, 15, 2514-31. (PubMed)

Lepiniec L., Thomas M., and Vidal J. (2003) From enzyme activity to plant biotechnology: 30 years of research on phosphoenolpyruvate carboxylase. Plant Physiol. Biochem. 41, 533-539.

Nesi N., Debeaujon I., Jond C., Stewart A.J., Jenkins G.I., CabocheM. and Lepiniec L. (2002) The TRANSPARENT TESTA16 Locus Encodes the ARABIDOPSIS BSISTER MADS Domain Protein and Is Required for Proper Development and Pigmentation of the Seed Coat. Plant Cell, 14, 2463-2479. (PubMed)

Steinborn K., Maulbetsch C., Priester B., Trautmann S., Pacher T., Geiges B., Küttner F., Lepiniec L., Stierhof Y-D., Schwarz H., Jürgens G. and Mayer U. (2002) The Arabidopsis PILZ group genes encode tubulin-folding cofactor orthologs required for cell division but not cell growth. Genes and development, 16, 959–971 (PubMed)

Nesi N., Jond C., Debeaujon I., Caboche M. and Lepiniec L. (2001) The Arabidopsis TT2 Gene Encodes an R2R3 MYB Domain Protein That Acts as a Key Determinant for Proanthocyanidin Accumulation in Developing Seed. Plant Cell, 13, 2099-2114 (PubMed)

Nesi N., Debeaujon I., Jond C., Pelletier G., Caboche M. and Lepiniec L. (2000) The TT8 Gene Encodes a Basic Helix-Loop-Helix Domain Protein Required for Expression of DFR and BAN Genes in Arabidopsis Siliques. Plant Cell, 12, 1863-1878 (PubMed)

Baud S, Guyon V, Kronenberger J, Wuillème S, Miquel M, Caboche M, Lepiniec L, Rochat C (2003) Multifunctional acetyl-CoA carboxylase1 is essential for very long chain fatty acid elongation and embryo development in Arabidopsis. Plant J 33, 75-86. (PubMed)

Baud S., Boutin J.P., Miquel M., Lepiniec L. and Rochat C (2002) An integrated overview of seed development in Arabidopsis thaliana ecotype WS. Plant Physiol Biochem 40, 151­160.

Brunaud V, Balzergue S, Dubreucq B, Aubourg S, Samson F, Chauvin S, Bechtold N, Cruaud C, De Rose R, Pelletier G, Lepiniec L, Caboche M, Lecharny A (2002) T-DNA integration into the Arabidopsis genome depends on sequences of pre-insertion sites. EMBO Reports 3, 1152-1157. (PubMed)

Buchner P, Rochat C, Wuillème S, Boutin JP (2002) Characterization of a tissue-specific and developmentally regulated b-1,3-glucanase gene in pea (Pisum sativum) Plant Mol Biol 49: 171-186. (PubMed)

Samson F, Brunaud V, Balzergue S, Dubreucq B, Lepiniec L, Pelletier G, Caboche M, Lecharny A (2002) FLAGdb/FST: a database of mapped flanking insertion sites (FSTs) of Arabidopsis thaliana T-DNA transformants. Nucleic Acid Res 30, 94-97. (PubMed)

Shen W-H, Parmentier Y, Hellmann H, Lechner E, Dong A, Masson J, Granier F, Lepiniec L, Estelle M, Genschik P (2002) Null Mutation of AtCUL1 Causes Arrest in Early Embryogenesis in Arabidopsis. Mol Biol Cell 13, 1916­1928. (PubMed)

Sørensen M, Mayer U, Lukowitz W, Robert H, Chambrier P, Jürgens G, Somerville C, Lepiniec L, Berger F (2002) Cellularisation in the endosperm of Arabidopsis thaliana is coupled to mitosis and shares multiple components with cytokinesis. Development 129, 5567-5576. (PubMed)

Steinborn K, Maulbetsch C, Priester B, Trautmann S, Pacher T, Geiges B, Küttner F, Lepiniec L, Stierhof YD, Schwarz H, Jürgens G, Mayer U (2002) The Arabidopsis PILZ group genes encode tubulin-folding cofactor orthologs required for cell division but not cell growth Genes Dev 16, 959­971. (PubMed)

Stone S, Kwong L, Matsudaira Yee K, Pelletier J, Lepiniec L, Fischer RL, Goldberg RB, and Harada JJ (2001) LEAFY COTYLEDON2 encodes a B3 domain transcription factor that induces embryo development. Proc Natl Acad Sci USA, 98, 11806­11811. (PubMed)

Balzergue S, Dubreucq B, Chauvin S, Le-Clainche I, Le Boulaire F, de Rose R., Samson F, Biaudet V, Lecharny A, Cruaud C, Weissenbach J, Caboche M, Lepiniec L (2001) Improved PCR-walking for large scale isolation of plant T-DNA borders. Biotechniques 30, 496-504. (PubMed)

Boisson M, Gomord V, Audran C, Berger N, Dubreucq B, Granier F, Lerouge P, Faye L, Caboche M, Lepiniec L (2001) Arabidopsis glucosidase I mutants reveal a critical role of N-glycan trimming in seed development. EMBO J 20, 1010-1019. (PubMed)

Dubreucq B, Berger N, Vincent E, Boisson M, Pelletier G, Caboche M, Lepiniec L (2000) The Arabidopsis AtEPR1 extensin-like gene is specifically expressed in endosperm during seed germination. Plant J 23, 643-652. (PubMed)

Lepiniec L, Thomas M, and Vidal J (2003) From enzyme activity to plant biotechnology: 30 years of research on phosphoenolpyruvate carboxylase. Plant Physiol Biochem 41, 533-539.

Baud S, Dubreucq B, Miquel M, Rochat C, Lepiniec L (2008) Storage reserve accumulation in Arabidopsis: Metabolic and developmental control of seed filling. In The Arabidopsis book, American Society of Plant Physiologists (ed.), USA

Dubreucq B, Grappin P, Miquel M., North N, Rochat C, Jullien M (2001) Approches moléculaires de la qualité et du développement des graines. Oléagineux, Corps Gras, Lipides 8: 487- 495.