Les séminaires ont lieu sur le Campus Montpellier SupAgro/INRA de La Gaillarde (2, place P. Viala Montpellier)
Jeudi 24 mai 2018
Salle 106 (Coeur d’Ecole) à 14h
Understanding the molecular control, spatial organization and physiological significance of endoreplication in Arabidopsis thaliana
Lieven de Veylder
VIB-UGent Center for Plant Systems Biology – Ghent – Belgium – www.psb.ugent.be
Somatic polyploidy caused by endoreplication is observed in arthropods, molluscs, and vertebrates, but is especially prominent in higher plants where it has been postulated to be essential for cell growth and fate maintenance. However, a comprehensive understanding of the physiological significance of plant endopolyploidy has remained elusive. Additionally, although major achievements in our understanding on the molecular control of endocycle onset have been achieved, the complete cell cycle toolbox that controls endoreplication is still unknown. To address these issues, we followed two major research lines. In one we applied a system biology approach to computationally model and experimentally verify a high-resolution DNA endoploidy map of the complete developing Arabidopsis thaliana root, revealing a remarkable spatiotemporal control of DNA endoploidy levels across tissues and a strong dependence on stress signals. Cellular analysis revealed that inhibition of endoreplication onset alters the nuclear-to-cellular volume ratio and leads to the appearance of cell structural changes. Complementary, we have screened for novel endocycle onset regulators through a EMS mutagenesis screen.
Contact : Antoine Martin