Changes in the proteome of pea (Pisum sativum L.) seeds germinating under optimal and osmotic stress conditions and subjected to post-stress recovery

Plants growing under natural conditions are exposed to a variety of stresses, which can lead to undesirable changes in the physiological processes and yielding. These changes can be regulated at different levels, resulting in the synthesis of specific proteins which participate in the plant's response to stress. The purpose of this study was to determine changes in the accumulation of proteins in germinating pea (Pisum sativum L.) seeds under optimal and osmotic (short- and long-term) stress conditions as well as recovery following a short-term stress. For identification of the proteins, two-dimensional electrophoresis and mass spectrometry (MALDI-TOF) were employed. Germination in optimal conditions increased the accumulation of several proteins involved in glycolysis, Krebs cycle, synthesis of fatty acids, cell growth, cellular transport and detoxification. Osmotic stress, in turn, depressed the accumulation of proteins involved in glycolysis, synthesis of fatty acids, detoxication, methionine conversions, cellular transport, translation, growth control and of cytoskeletal proteins, but raised the accumulation of enzymes of the tricarboxylic acid cycle as well as proteins participating in signal transduction and protection (chaperones). One protein, 6a-hydroxymaackian-3-O-methyltransferase, which is involved in the synthesis of pisatin, was present only under osmotic stress conditions and recovery. Pisatin is synthesized mainly in response to microbiological infections and under stress conditions, indicating its key role in the acquisition of stress tolerance by plants

Biologie des graines : des espèces modèles aux légumineuses cultivées

Dpmt BAP Pôle GEAPS

Role of the arbuscular mycorrhizal symbiosis on S-uptake and S-starvation resistance in Medicago truncatula

International audienceDue to its key role in the biosynthesis of many S-containing compounds, sulphur is a macronutrient essential for plant growth, development, and response to various abiotic and biotic stresses. Sulphate represents a very small portion of soil S pull and it’s the only form that plant roots can take up and mobilize through H+-dependent co-transport processes implying sulphate transporters. Unlike the other organically bound forms of S, sulphate is normally leached from soils due to its solubility in water, thus reducing its availability to plants. Although our knowledge of plant sulphate transporters has been growing significantly in the last decades, little is still known about the effect of the arbuscular mycorrhiza (AM) interaction on S-uptake and S-stress resistance. For this reason our studies focused on the mycorrhizal interaction between the leguminous model plant Medicago truncatula and the arbuscular mycorrhizal fungus Rhizophagus intraradices (ex Glomus intraradices). Carbon, nitrogen and sulphur measurements in different plant tissues and expression analysis of genes encoding putative Medicago sulphate transporters (MtSULTRs) were performed to better understand the beneficial effects of mycorrhizal interaction at different sulphate concentrations. The putative effects of mycorrhizal interaction were also assessed on seed weight and quality through protein content and 1-D gel analyses. Among the 8 putative MtSULTRs in-silico identified; some of them were differentially transcribed in roots and leaves due to sulphate concentration and/or upon mycorrhization, potentially defining a switch between direct (DP) and mycorrhizal (MP) sulphate uptake pathways

Transcriptional response of Medicago truncatula sulphate transporters to arbuscular mycorrhizal symbiosis with and without sulphur stress

International audienc

Role of the AM interaction on S-uptake and S-starvation resistance in <em>Medicago truncatula</em>

International audienceSulphur is an essential macronutrient for plant growth, development, and response to various abiotic and biotic stresses due to its key role in the biosynthesis of many S-containing compounds. Sulphate represents a very small portion of soil S pull and it’s the only form that plant roots can uptake and mobilize through H+-dependent co-transport processes implying sulphate transporters. Unlike the other organically bound forms of S, sulphate is normally leached from soils due to its solubility in water, thus reducing its availability to plants. Although our knowledge of plant sulphate transporters has been growing significantly in the last decades, little is still known about the effect of the arbuscular mycorrhiza interaction on sulphur uptake. Carbon, nitrogen and sulphur measurements in plant parts and expression analysis of genes encoding putative Medicago sulphate transporters (MtSULTRs) were performed to better understand the beneficial effects of mycorrhizal interaction on Medicago truncatula plants colonized by Glomus intraradices at different sulphate concentrations. Mycorrhization significantly promoted plant growth and sulphur content, suggesting increased sulphate absorption. In-silico analyses allowed identifying 8 putative MtSULTRs phylogenetically distributed over the 4 sulphate transporter groups. Some putative MtSULTRs were transcribed differentially in roots and leaves and affected by sulphate concentration, while others were more constitutively transcribed. Mycorrhizal-inducible and -repressed MtSULTRs transcripts were identified allowing to shed light on the role of mycorrhizal interaction in sulphate uptake

Une fonction distincte du transporteur de sulfate SULTR3;5 selon la source d’azote chez Medicago truncatula

National audienceLe soufre est un élément essentiel pour le fonctionnement des plantes de par son implication dans de nombreux processus (ex. synthèse d’acides aminés, de glutathion). La source majoritaire de soufre pour la plante est le sulfate. Celui-ci est absorbé au niveau des racines puis distribué aux différents organes grâce aux transporteurs de sulfate (SULTR). Il existe 4 classes de SULTR chez les plantes tous caractérisés par 12 motifs transmembranaires et un domaine STAS (Sulphate Transporter and AntiSigma factor antagonist). Alors que les fonctions des transporteurs des groupes 1, 2 et 4 soient majoritairement connues, peu de rapports traitent de la fonction des membres de la classe 3. En utilisant Medicago truncatula comme modèle, l’objectif de la thèse est d’approfondir la compréhension du rôle de MtSULTR3;5 dans la nutrition de la plante dans des conditions environnementales fluctuantes. Nos résultats montrent que le phénotype de mutants d’insertion pour ce gène diffère selon la source d’azote (minérale ou atmosphérique). En condition d’assimilation des nitrates la mutation cause une diminution générale de la biomasse et des quantités de soufre et d’azote, suggérant un rôle de MtSULTR3;5 dans l’absorption racinaire du sulfate, une fonction inédite pour un transporteur du groupe 3. En revanche, lorsque la nutrition azotée repose sur la fixation symbiotique, cette diminution de l’apport en soufre n’est pas observée tandis que les quantités d’azote, la masse des nodules ainsi que leur contenu en soufre et en azote diminuent chez le mutant. Nos résultats suggèrent un rôle différentiel de MtSULTR3;5 selon la source d’azote, à l’interface entre le métabolisme de l’azote et du soufre en présence de nitrate dans le sol pour maintenir l’équilibre N/S dans la plante et dans le fonctionnement des nodosités en absence de nitrate

The seed nuclear proteome

OPEN ACCESS Cette revue date de 2010 mini review article Repetto, Ombretta : ex UMR LEG 0102, n'a jamais intégré l'UMR Agro Present adress : CRO, IRCCS, Centro di Riferimento Oncologico, Istituto di Ricovero e Cura a Carattere Scientifico - Proteomics Core Facility, Experimental and Clinical Pharmacology, Aviano PN, Italie. BAP GEAPSI CT2International audienceUnderstanding the regulatory networks coordinating seed development will help to manipulate seed traits, such as protein content and seed weight, in order to increase yield and seed nutritional value of important food crops, such as legumes. Because of the cardinal role of the nucleus in gene expression, sub-proteome analyses of nuclei from developing seeds were conducted, taking advantage of the sequences available for model species. In this review, we discuss the strategies used to separate and identify the nuclear proteins at a stage when the seed is preparing for reserve accumulation. We present how these data provide an insight into the complexity and distinctive features of the seed nuclear proteome. We discuss the presence of chromatin-modifying enzymes and proteins that have roles in RNA-directed DNA methylation and which may be involved in modifying genome architecture in preparation for seed filling. Specific features of the seed nuclei at the transition between the stage of cell divisions and that of cell expansion and reserve deposition are described here which may help to manipulate seed quality traits, such as seed weight

Sulfur metabolism in plants - Regulatory aspects and Sulfur in the foos chain, agriculture and the environment, Sulfur metabolism and transport in developing seeds

International audienc

Storage cells – oil and protein bodies

BAPGEAPSIMolecular Cell Biology of the Growth and Differentiation of Plant Cells encompasses cell division, cell enlargement and differentiation; which is the cellular basis of plant growth and development. Understanding these developmental processes is fundamental for improving plant growth and the production of special plant products, as well as contributing to biological understanding. The dynamics of cells and cellular organelles are considered in the context of growth and differentiation, made possible particularly by advances in molecular genetics and the visualization of organelles using molecular probes. There is now a much clearer understanding of these basic plant processes of cell division, cell enlargement and differentiation. Each chapter provides a current and conceptual view in the context of the cell cycle (6 chapters), cell enlargement (5 chapters) or cell differentiation (9 chapters). The book provides state of the art knowledge (and open questions) set out in a framework that provides a long term reference point. The book is targeted at plant cell biologists, molecular biologists, plant physiologists and biochemists, developmental biologists and those interested in plant growth and development. The book is suitable for those already in the field, plant scientists entering the field and graduate students

Adapter la composition protéique des graines de légumineuses en fonction des usages

National audienc