Search results for " expression"
showing 10 items of 4731 documents
Networks of Seed Storage Protein Regulation in Cereals and Legumes at the Dawn of the Omics Era
2012
BAP GEAPSI CT2 (BAP); International audience; Finely regulated and orchestrated events occur during seed development and germination in different cell organelles (mitochondria, peroxisomes, plastids, vacuoles, endoplasmic reticulum, oil bodies and nuclei). Therefore, some of the ongoing investigations pass through sub-cellular organelle purifications for a deeper comprehension of these complex developmental processes. In seed biology, recent ambitious efforts in proteomics have been directed toward organelle isolation from seeds and high-throughput protein separation and identification by mass spectrometry at defined developmental stages. The construction of reference maps allowed identifyi…
Correlating stress and somatic embryogenesis for NBT: myth or reality?
2018
Global warming and growing demography have increased demand for agronomic resources, leading to increasing lack of land suitable for agriculture and provoking several abiotic stresses which, added to biotic ones, result in physiological and metabolic disorders that impact on crop yield when most needed. Reducing this impact is a major scientific and agronomic challenge and biotechnology would be an efficient alternative. However, to reduce risks of somaclonal variation among regenerants it is better to produce them by somatic embryogenesis directly from explants or gametes, or indirectly from callus or cell suspensions. Thus, globular embryos regenerate and develop through to the heart, tor…
Transcriptional response of Medicago truncatula sulphate transporters to arbuscular mycorrhizal symbiosis with and without sulphur stress
2013
Sulphur 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 is 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 past decades, little is still known about the effect of…
Discrimination des expressions faciales et environnement olfactif - Corrélats cérébraux en électroencéphalographie (EEG) chez l'adulte et le très jeu…
2019
This thesis examines the mechanisms subtending the perception of emotional facial expressions and their early development using a Fast Periodic Visual Presentation (FPVS) approach coupled with electroencephalography (EEG). More specifically, we tried to characterize brain responses reflecting facial expression discrimination and to determine whether hedonic odor contexts influence these responses in adults (studies 1 and 2), and in infants at different developmental stages (studies 3 and 4). We showed specific responses to the discrimination of every facial expression in the adult brain, indicating rapid and automatic categorization of basic facial expressions (study 1). In addition, we rev…
Inactivation of PadR, the repressor of the phenolic acid stress response, by molecular interaction with Usp1, a universal stress protein from Lactoba…
2009
ABSTRACT The phenolic acid decarboxylase gene padA is involved in the phenolic acid stress response (PASR) in gram-positive bacteria. In Lactobacillus plantarum , the padR gene encodes the negative transcriptional regulator of padA and is cotranscribed with a downstream gene, usp1 , which encodes a putative universal stress protein (USP), Usp1, of unknown function. The usp1 gene is overexpressed during the PASR. However, the role and the mechanism of action of the USPs are unknown in gram-positive bacteria. Therefore, to gain insights into the role of USPs in the PASR; (i) a usp1 deletion mutant was constructed; (ii) the two genes padR and usp1 were coexpressed with padA under its own promo…
Visual exploration of face and facial expression in infancy: A qualitative approach of cognitive and social development
2016
International audience; This article proposes a methodological consideration for the use of "head free" eye-tracking systems, which allowed to extend this technique to the study of infant skills. It explores how the technological developments enable a more qualitative approach, which offers the possibility of considering "how" in addition to "how long" the infant looks at a visual scene, especially the scene of the face.
Study of biogenic amines metabolism in wine lactic acid bacteria
2011
Biogenic amines are indesirable compounds found in fermented products like wine. Lactic acid bacteria from wine, including Oenococcus oeni, the main actor of malolactic fermentation, are able to produce these molecules from nitrogenous precursors. In order to limited biogenic amines accumulation, it is necessary to understand the role of this production by strains responsible for the synthesis of these metabolites in food. That is why the European BiamFood project was put in place. Along my thesis, molecular tools were developed in order to mutate O. oeni genes (encoding decarboxylases), and to express genes of interest. Genetic clusters hdc from L. higardii and odc from O. oeni, responsibl…
Communication and Autoinduction in the species Listeria monocytogenes
2014
International audience; In order to withstand changes in their environment, bacteria have evolved mechanisms to sense the surrounding environment, integrate these signals and adapt their physiology to thrive under fluctuating conditions. Among these mechanisms, the ability of bacteria to exchange information between cells has become a dynamic field of interest for microbiologists over the past four decades. First described by Nelson et al.,1 this phenomenon often referred as either cell-cell communication, Quorum Sensing and/or AutoInduction involves the synthesis of small signal molecules called autoinducers. These signal molecules may be sensed by the bacterial population in the vicinity …
Characterization of Pea (Pisum Sativum L.) genes implicated in arbuscular mycorrhiza formation and function
2010
The arbuscular mycorrhizal (AM) association results from a successful interaction between the genomes of the two symbiotic partners. In this context, the aim of my research was to better characterize the role of the late stage symbiosis-related pea genes PsSym36, PsSym33 and PsSym40 in the functional AM (i) by investigating the effect of mutations in the three genes on fungal and plant gene responses and (ii) by creating conditions for the localization of two of the genes, PsSym36 and PsSym40, on the pea genetic map for future map-based cloning. The expression of a subset of ten fungal and eight plant genes,previously reported to be activated during mycorrhiza development, was compared in G…
Genes encoding transcription factors in Glomus intraradices and their expression at the appressoria stage of arbuscular mycorrhiza interactions
2007
International audience; Molecular pathways governing the life cycle of arbuscular mycorrhizal (AM) fungi and their symbiotic interactions with root tissues are not yet fully understood. Most studies fo fungal responses to host plants have targeted developmental stages before root contact (germinating spores), or after root colonization (intraradical mycelium). We are focusing on the early cell events of appressoria contact with the root surface which are essential to the successful outcome of the AM symbiosis. Recent monitoring of Glomus intraradices gene expression at this stage has revealed differential fungal responses to roots of host and non-host (Myc- mutants) M. truncatula (Seddas et…