Search results for "graines"
showing 10 items of 20 documents
Influence of nitrogen availability on seed nitrogen accumulation in pea
1999
International audience; The final seed nitrogen concentration (the ratio of seed N and dry matter content) is highly variable in pea (Pisum sativum L.) and N remobilization during seed filling may limit yield by restricting the seed filling period. This study was conducted to determine how seed N accumulation is regulated in pea. The effect of N availability and distribution on individual seed N accumulation rate at different nodes was investigated in three genotypes grown in the field and glasshouse under various levels of N fertilizer, depodding, and defoliation. The N content of vegetative plants parts (stems, leaves, podwalls) and seeds from three mainstem nodes were regularly recorded.…
Hypertrophic pachymeningitis and cerebral venous thrombosis in myeloperoxidase-ANCA associated vasculitis
2019
Hypertrophic pachymeningitis (HP) is a circumscribed inflammatory process that thickens meninges with fibrous adhesions. Among the causes of HP, vasculitis and autoimmune disease should be considered; myeloperoxidase (MPO)-antinuclear cytoplasmatic antibodies (ANCA)-positivity can be the only
Grain legume seed filling in relation to nitrogen acquisition: A review and prospects with particular reference to pea
2001
International audience; Seed filling depends not only on the instantaneous supply of C and N, but also on their remobilisation from vegetative organs. C supply during seed filling depends mostly on current photosynthesis, but N assimilation and N$_2$ fixation decline during seed filling, with newly acquired N generally insufficient for the high seed demand. As seeds are strong sinks for mobilised nutrients, seed growth becomes metabolically closely associated with N remobilisation. N remobilisation from vegetative tissues to filling seeds interacts with photosynthesis since it induces senescence, which reduces the seed filling period. Hence improved grain legume seed filling requires either…
Effet d'une carence en soufre combinée à un stress hydrique chez le pois protéagineux : Etude des mécanismes moléculaires mis en jeu dans les organes…
2019
Pea (Pisum sativum L.) is a grain legume crop that produces seeds rich in proteins for food and feed and, thanks to its symbiosis with nitrogen-fixing bacteria, enriches the soil with nitrogen. The wider development of pea cultivation is therefore a major agroecological challenge. Water stress combined with sulfur deficiencies in soils (S is a macroelement necessary for plant defense reactions) are two abiotic stresses that interact in the current context of climate change. However, the molecular mechanisms underlying pea adaptation to water stress and their modulation by sulfur nutrition remain to be elucidated. The objectives of this thesis were, first, to describe the impact of an intera…
Novel missense mutation in the ATP1A2 gene associated with atypical sporapedic hemiplegic migraine
2019
Hemiplegic migraine (HM) is a rare subtype of migraine with aura in which attacks include transient motor weakness or hemiparesis that can last several days. HM is linked to mutations in three different genes, CACNA1A, ATP1A2 and SCN1A, which encode for ion transporters. The clinical spectrum includes atypical symptoms such as impaired consciousness, epileptic seizures, permanent cerebellar ataxia or mental retardation. We describe a novel mutation found in the ATP1A2 gene in a patient with late-onset HM. His attacks were characterised by motor weakness associated with altered mental status, diplopia and ataxia. He also showed up MRI abnormalities and incomplete response to prophylactic the…
Projet BILAG : une bibliométrie de la littérature scientifique mondiale sur les légumineuses à graines pour comprendre la dynamique de la recherche s…
2018
Quel poids ont les différentes disciplines scientifiques dans la recherche mondiale sur les légumineuses à graines ? Quelles sont les espèces les plus étudiées et sur quels sujets ? Comment évoluent les champs de connaissance de la recherche sur les légumineuses à graines ? Quels champs de connaissances émergent et se restructurent ? Quelle est la place des différents instituts de recherche dans ce maillage, et tout particulièrement ceux des pays francophones ? Pour répondre à ces questions, un groupe d'experts interdisciplinaires sur les légumineuses et d'ingénieurs de l'information scientifique, a moissonné/collecté un corpus d'articles scientifiques sur les légumineuses à graines (telles…
The role of biotic interactions in a prey-predator system : the case of predation and regulation of weed seeds by carabids.
2020
For the transition towards agricultural production systems that are less dependent on herbicides, the use of weed regulation by seed-eating carabids is of great interest. Weed seed predation by carabids is variable and occurs within a complex context of many biotic interactions. This complexity partly explains our current inability to predict levels of in-field weed regulation. In this thesis, I analysed variations in the levels of predation and biological regulation of weeds and determined how they respond to two classes of biotic interactions: 1) the availability of alternative prey; and, 2) intra- and inter-specific interactions between the carabids themselves. Field measurements carried…
Impact of GMOs within cropping systems: towards a more systemic approach
2004
International audience
Importance de la variabilité génétique bactérienne sur le fonctionnement de la symbiose Rhizobium leguminosarum biovar viciae avec le pois (Pisum sat…
2008
Les irrégularités de rendement et de teneur en protéine des graines que présente la culture du pois sont, en partie, liées à des problèmes de nutrition azotée. En tant que légumineuse, la nutrition azotée du pois repose à la fois sur la fixation symbiotique de l’azote atmosphérique et sur l’absorption racinaire des nitrates du sol. Notre principal objectif a été de déterminer si le partenaire bactérien, Rhizobium leguminosarum biovar viciae (Rlv), peut être un facteur limitant de la nutrition azotée et du rendement du pois. La variabilité génétique des Rlv et les facteurs influençant la structure des populations de Rlv à l'état libre et symbiotiques ont été étudiés. La signification de la d…
Dynamique et assemblage des communautés adventices : Approche par modélisation statistique
2011
To develop solutions for a productive and sustainable agriculture, principles, theories, andmethods of ecology may contribute to understand the biological processes governing the agroecosystem.The present case study was based on data collected by a network of observatories of weeds covering the whole of France (‘Biovigilance Flore’) and aimed at establishing forrules governing the assemblage and dynamics of weed communities in fields grown with annual crops. We particularly studied the possible relationships between species within acommunity, as well as the relationships between communities and their environment. Analyses were based on species abundances to take account of their effect on c…