Bonjour,
La direction de l‘unité propose une réunion d’échange avec le collège des ITAs,
le mercredi 20 novembre à partir de 9h30, en salle Bibliothèque.
Comme précédemment, nous serons à votre écoute et répondrons à vos questions et suggestions.
Bien cordialement,
Christophe
Proposé par l’équipe Ticer
Séminaire IBIP
Les séminaires ont lieu sur le Campus Montpellier SupAgro/INRA de La Gaillarde (2, place P. Viala Montpellier)
Jeudi 21 novembre 2024 à 14h00 – Amphi 208 Cœur d’Ecole
Camila Goldy
(RDP Lyon)
The Actin cytoskeleton is required to maintain the cell division orientation against the cellular geometry
In plants, cell division is pre-determined before mitosis by the formation of a plant-specific structure called the microtubule preprophase band (PPB). While the microtubule cytoskeleton is known to play a central role in cell division, the actin cytoskeleton has traditionally been considered secondary. However, plants lacking a PPB or with disrupted microtubules rarely exhibit defects in cytokinesis orientation, suggesting the existence of an upstream or redundant mechanism. Interestingly, actin filaments have been found to polarize along the apicobasal faces of cells. Through a combination of cell biology techniques, pharmacological treatments, and genetic tools, along with integrated 3D quantification, we discovered that actin plays a critical role in establishing the orientation of cell division, acting in a non-cell-autonomous manner.
Contact : yann.boursiac@inrae.fr
Séminaires et théses à venir :
2024
Lundi 2 décembre : Kevin Bellande (Contact : benjamin.peret@cnrs.fr)
Jeudi 5 décembre : Soutenance de thèse de Jordan Courrege
Jeudi 12 décembre : Soutenance de these de Roxane Doireau
Lundi 16 décembre : Soutenance de these d’Omar Hdedeh
2025
Jeudi 23 janvier : Matthieu Platre contact : sandra.cortijo@cnrs.fr)
https://www1.montpellier.inra.fr/wp-inra/bpmp/actualites/ rubrique Séminaires (2020-2025)
Contacts IBIP :
Sabine Zimmermann (sabine.zimmermann@cnrs.fr)
Justine Drouault (justine.drouault@inrae.fr)
Jessica Bertheloot (jessica.bertheloot@inrae.fr)
Chantal Baracco (chantal.baracco@inrae.fr)
Séminaire IBIP
Les séminaires ont lieu sur le Campus Montpellier SupAgro/INRA de La Gaillarde (2, place P. Viala Montpellier)
Lundi 02 décembre 2024 à 14h00 – Amphi 208 Cœur d’Ecole
Kevin Bellande
(Laboratory of Molecular and Cellular Biology – Switzerland)
Conserved developmental trajectories channeling lateral root primordium morphogenesis
Improving crop resilience through enhanced root system architecture (RSA) is critical for adaptation to changing environmental conditions. Lateral root (LR) formation, which is predominantly regulated by auxin signalling pathways, is a complex process. We recently presented the first developmental atlas of LR development in the model grass species Brachypodium distachyon (Bd), revealing the reactivation of the endodermal cell cycle that contributes to the formation of root cap and columella cells in emerging LRs. Interestingly, our results suggest that auxin signalling, as indicated by DR5 promoter activity, is not evident in the phloem pole pericycle or during early LR development, but correlates with cell wall modifications during the emergence of the LR primordium (LRP).
In a comparative analysis of Bd21 and Bd21-3 accessions, we observed similar LRP synchronisation after root tip removal, but distinct LR architecture thereafter. RNAseq analysis revealed distinct early and late responses in both accessions, with significant overlap of differentially expressed genes at later time points. An enrichment of cell wall related processes was observed and patterns of cell wall remodelling gene families varied during early LR formation. In addition, we identified several GDSL/GELP genes with similar expression patterns during LR formation in both Brachypodium and Arabidopsis, as well as conserved GDSL protein structures. Notably, the orthologous copy of AtGELP38, identified as a suberin synthase in Arabidopsis, BdGELP38, was expressed in the endodermis overlying the LRPs and functionally rescued the absence of the suberin phenotype in gelpquint mutants.
Dissecting the trajectories of cell types and whether there are regulatory mechanisms that could be part of conserved modules for root branching in general would be of further interest.
Bellande Kevin1,2 * ; De Jesus Vieira Teixeira Cristovāo1 ; Marc-Martin Sophie1 ; Badet Thomas3 ; Péret Benjamin2 ; E.M. Vermeer Joop1 *
1 Laboratory of Molecular and Cellular Biology, Institute of Biology, University of Neuchâtel, Rue Emile Argand 11, CH-2000, Neuchâtel, Switzerland.
2 IPSiM, University of Montpellier, CNRS, INRAE, Institut Agro, Montpellier, France.
3 Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Rue Emile Argand 11, CH-2000, Neuchâtel, Switzerland.
* Correspondances : kevin.bellande@cnrs.fr; josephus.vermeer@unine.ch
Contact : benjamin.peret@cnrs.fr
Séminaires et thèses à venir :
2024
Jeudi 5 décembre : Soutenance de thèse de Jordan Courrege
Jeudi 12 décembre : Soutenance de these de Roxane Doireau
Lundi 16 décembre : Soutenance de these d’Omar Hdedeh
2025
Jeudi 23 janvier : Matthieu Platre (contact : sandra.cortijo@cnrs.fr)
https://www1.montpellier.inra.fr/wp-inra/bpmp/actualites/ rubrique Séminaires (2020-2025)
Contacts IBIP :
Sabine Zimmermann (sabine.zimmermann@cnrs.fr)
Justine Drouault (justine.drouault@inrae.fr)
Jessica Bertheloot (jessica.bertheloot@inrae.fr)
Chantal Baracco (chantal.baracco@inrae.fr)
Les soutenances de thèses IPSiM ont lieu sur le Campus Montpellier SupAgro/INRA de La Gaillarde (2, place P. Viala Montpellier)
Avis de Soutenance
Jeudi 05 décembre 2024 à 14h00 – Amphi 208
Monsieur COURREGES-CLERCQ Jordan
(Equipe-SYSYTEMS)
Soutiendra publiquement ses travaux de thèse intitulés
Rôle et fonction des plateformes de signalisation membranaires contenant la Rho GTPase ROP6 lors de la signalisation cellulaire
Ecole Doctorale : GAIA – Biodiversité, Agriculture, Alimentation, Environnement, Terre, Eau
Spécialité : BIDAP – Biologie, Interactions, Diversité Adaptative des Plantes
Etablissement : Université Montpellier
Unité de recherche : IPSiM – Institut des Sciences des Plantes de Montpellier
Devant le jury composé de:
Marie BARBERON, Professeur assistant, Université de Genève – Rapportrice
Yohann BOUTTE, Directeur de recherche, CNRS, Bordeaux – Rapporteur
Soazig GUYOMARC’H, Professeur, Université de Montpellier – Examinatrice
Christophe PERIN, Directeur de Recherche, CNRS, Montpellier – Examinateur
François PARCY, Directeur de recherche, CNRS, Grenoble – Invité
Transcription factors represent a class of proteins found in all living organisms, characterized by their ability to interact both with DNA and various partners to regulate the expression of target genes. This regulation is essential for maintaining the organization and dynamics of gene networks. However, despite their central role in controlling many cellular functions, the biophysical behavior of transcription factors within cells remains largely poorly understood. Studying their diffusion and organization in real time, directly in plant cells, could reveal how interactions occur in the nucleus, thus shedding light on gene regulation mechanisms. Each family of transcription factors is distinguished by specific criteria, such as the presence of specific binding sites. Analyzing the diffusion model of one family member could help predict common transcriptional strategies among other members. Nevertheless, each transcription factor exhibits unique behavior influenced by various parameters, including its structure, its ability to navigate and bind to specific targets, as well as external factors such as the local organization of the genome, which may be more or less condensed, and possible interactions with other partners in this environment at a given time.
This thesis work focused on direct observations, analyses, and characterizations of the behavior of transcription factors in root protoplasts from seedlings. The technique of single-particle tracking photoactivated localization microscopy (sptPALM), combined with a molecular biology approach enabling controlled nuclear targeting of molecules, was developed and adapted for experiments on plant material. Through this approach, specific behaviors for each factor were identified. The dynamic characteristics of these same factors were determined using directed mutagenesis, under different chromatin conditions, by varying the composition of the observation medium or in the absence of transcription factor partner proteins. As a result, several distinct behaviors of transcription factors were highlighted to explain their biophysical conduct within plant cells.
Bonjour,
La direction de l‘unité propose une réunion d’échange avec les collègues non-permanents,
le vendredi 13 décembre de 14h à 15h30, en salle Bibliothèque
Comme précédemment, nous serons à votre écoute et répondrons à vos questions et suggestions.
Bien cordialement,
Christophe
__________________________________________________________________________
Dear all,
The management of the unit proposes an exchange meeting with the non-permanent colleagues,
on Friday December 13 from 2 p.m. to 3:30 p.m., in the Library room.
As before, we will listen to you and answer your questions and suggestions.
Best regards,
Christophe
Ordre du jour
- Bilans annuels : prévention, formation, budget du laboratoire
- Informations sur le processus d’évaluation HCERES
Tous les assistants prévention, correspondants formation et gestionnaires financiers sont invités à ce conseil pour, a minima, participer au bilan les concernant
A l’occasion de la création de lignes électriques 16A pour les futures enceintes climatiques d’IPSIM, une coupure électrique au niveau du tableau divisionnaire Nord/Est du rez de chaussée aura lieu le mercredi 11/12 entre 6h et 8h du matin. Cette coupure ne devrait pas impacter les installations du LEPSE, mais restons vigilant.
Cette coupure impactera notamment, la laverie, les petits labo de la halle technique 007, la pièce des Aralabs, celle de la production d’eau osmosée laverie, salle phytotron, salle hotte à flux laminaire et les bureaux Est du R de C
Ordre du jour:
- Informations diverses
- Demandes de postes INRAE
L’objectif est de faire un premier point sur nos demandes précédentes et sur d’éventuelles nouvelles demandes, à faire remonter en février 2025. - Relation internationales
Un tour de table sera réalisé afin d’identifier et discuter nos points forts et de nouvelles tendances