Search results for "DOP"

Impact of endopolyploidy on seed coat development and cell expansion in Medicago truncatula

2013

Growth of the seed coat is regulated by genetic interactions between maternal and filial tissues that ultimately establish seed size. However, endopolyploidy is one of the welldocumented factors controlling organ size. During seed development, the arrest of cell division at 4 DAP in the expanding seed coat is compensated for by cell elongation. Thus, the ploidy status of seed coat nuclei was assessed in order to determine if there is any correlation of endopolyploidy with cell elongation. In 10 DAP seed sections, the DAPI-integrated fluorescence, which correlates to DNA quantity, was measured in the seed coat parenchyma nuclei using the diploid embryo nuclei as internal control. Significant…

Microglia and α-synuclein implication in Parkinson's disease

2011

Age-related neurodegenerative disorders like Parkinson’s disease take an enormous toll on individuals and on society. Despite extensive efforts, Parkinson’s disease remains incurable and only very limited treatments exist. Indeed, Parkinson’s pathogenesis is still not clear and research on its molecular mechanisms is ongoing. In this study, we focused our interest on two abnormal events occurring in Parkinson’s patients, namely α-synuclein aggregation and microglial activation. We first investigated α-synuclein and its abnormal polymerisation. For this purpose, we developed novel methods, which allowed the in vitro production of different types of α-synuclein oligomers. Using highly sensiti…

Grape cultivar affects larval and female fitness of the European grapevine moth, Lobesia botrana (Lepidoptera: Tortricidae)

2005

8 pages; International audience

Host preference in dark septate root endophytes of prairie grasses

2007

International audience; Microbiological examination of prairie grass roots usually reveals the presence of diverse mycorrhizal and dark septate endophytic (DSE) fungi. Some of these fungi can enhance plant resistance to abiotic stress in extreme environments. The host specificity of two DSE fungi isolated from pure stands of crested wheatgrass and Russian wildrye in southwest Saskatchewan was assessed in microcosms. Pure cultures of endophytic fungal isolates were obtained after plating surface sterile root pieces on Potato dextrose agar. Plugs containing these fungi were used to individually inoculate germinated surface sterile seeds of crested wheatgrass and Russian wildrye, and control p…

Calcium signaling in plant defense: involvement of subcellular compartments and glutamate receptorsCalcium signaling in plant defense: involvement of…

2012

Etude du système de perception des chito--oligosaccharides chez la vigne et rôle dans l'immunité.

2014

Rapport de stage Master II R SPE IPM; Master

Establishment of tools for investigating pyoverdine impact on iron homeostasis and plant defense responses

2013

Iron, the fourth major element in the Earth crust, is essential for growth and development of living organisms. However, due to its low solubility in the soil, it is weakly available for plants and micro-organisms. To efficiently assimilate iron, living organisms have evolved specific strategies. In plants such as Arabidopsis thaliana three trans-membrane proteins are involved in iron assimilation while in bacteria such as Pseudomonas fluorescens iron is taken up from the soil thanks to molecules displaying high affinity for iron called siderophores. It has been recently shown that pyoverdine, the major siderophore of the beneficial bacterium Pseudomonas fluorescens, is assimilated by A. th…

Characterization of the role of flagellin in the innate immunity triggered by the endophytic pgpr burkholderia phytofirmans in arabidopsis and grapev…

2014

International audience

Analysis of the cross‐regulation between immunity, growth and iron homeostasis in plants

2019

The existence of a tightly regulated balance between growth and immunity in plants has recently emerged. In this study, we challenged this concept thanks to the biological model pyoverdine-Arabidopsis thaliana. Pyoverdine is a siderophore produced by the plant growth promoting rhizobacteria Pseudomonas fluorescens C7R12. Under iron deficiency, P. fluorescens excretes the iron free form of pyoverdine (apo‐pyo) in the soil. Once chelated with iron (ferri‐pyo), the complex is internalized by the bacteria. We demonstrated that Arabidopsis thaliana plants treated by apo‐pyo in a medium containing or not iron internalize pyoverdine. Interestingly, apo‐pyo-treated plants did not show a typical gro…

The plant resistance inducer β-aminobutyric acid (BABA) induces an iron deficiency response in A. thaliana

2012

β-aminobutyric acid (BABA) is a well-known plant resistance inducer. However, the molecular mechanisms underlying its effects are poorly understood. In the present study, we investigated whether BABA could act through the modification of iron homeostasis in Arabidopsis thaliana. Supporting this assumption, we obtained first evidences that BABA chelates iron with high affinity. We showed that pre-treatment of plants with BABA induced a drastic but transient iron deficiency response. Quantification of iron indicated that this response is related to the perturbation of iron distribution/availability rather than a reduction of iron assimilation. Finally, we provided evidence that the iron defic…