Institut de Biologie Mol√©culaire des Plantes
What we work upon
Plants are sessile organisms that are continuously exposed to various stresses during their development. They have developed mechanisms to regulate their growth and adapt to these stresses, through signaling pathways transmitted to the nucleus. Our IBMP group aims at deciphering these pathways using interdisciplinary approaches (-omics, cellular, physics, genetics and (epi)genomics) through the study of key players, including the so-called GIP proteins, located at the nucleo-cytoplasmic interface:
1) The role of GIPs and their partners is studied in response to mechanical stress perceived at the nuclear envelope and our goal is to identify the underlying molecular mechanisms.
2) GIPs were identified on both sides of the nuclear envelope and may participate in signal transduction from microtubules nucleation sites located at the outer nuclear membrane to the centromeres located at the inner nuclear membrane.
We aim at determining whether GIPs can be sensors of oxidative stress (ROS) and relay or control responses to environmental stresses, notably via an oxidative signaling pathway.
3) In addition, we also aim at deciphering the role of GIPs in DNA damage response and more extensively on molecular mechanisms involving DNA damage response of the plant (epi)genome upon genotoxic stress exposure with a particular focus on small RNA mediated processes, DNA methylation and excision DNA repair. This project will extend our knowledge on the complexity of pathways involved in the regulation of genome and epigenome integrity.
Our contribution for DialogProTec
The goal is to identify natural modulatory effects on plant growth induced by contact with exudates of fungal cultures. Using transformation techniques, a series of Arabidopsis lines expressing fluorescently labelled proteins were established . We will use lines fluorescently labelling cytoskeletal polymers to link cytoskeletal dynamics with root growth capabilities. Indeed, fungal compounds secreted in the culture medium may have positive or negative effects on plant growth. Partner IBWF will provide a variety of fungal cultures. We will first measure both the germination efficiency and the growth rate of plants in a bio-chip developed by KIT-IMT in order to select fungi able to deliver to their environment products which, could replace those chemicals that are currently used in agriculture.
The expected effects might be either activation or inhibition of growth. Then, the effect of these products will be checked on the organization and dynamics of both, the microtubule and actin, cytoskeletons under high magnification confocal microscopy. Once a fungal candidate is selected, partner ALUF will identify the active compound which will be further purified and tested for its activity in similar bio-chip conditions. The goal is to characterize a natural product active at low concentration and able to replace herbicides or artificial growth stimulators.
Schmit A.C., and Lambert A.M. (1987). Characterization and dynamics of cytoplasmic F-actin in higher plant endosperm cells during interphase, mitosis and cytokinesis. J. Cell Biol. 105 : 2157-2166. (IF 9,8)
Vos J.W., Pieuchot L., Evrard J.L., Janski N., Bergdoll M., de Ronde D., Perez L.H., Sardon T., Vernos I. and Schmit A.C. (2008). The plant TPX2 protein regulates prospindle assembly before nuclear envelope breakdown. Plant Cell. 20 : 2783-97. (IF 10,5)
Janksi N., Masoud K., Batzenschlager M., Herzog E., Evrard J.L., Houln√© G., Bourge M., Chabout√© M.E. and Schmit A.C. (2012) GCP3-interacting proteins 1 and 2 are required for gamma-tubulin complex protein localization, spindle integrity and chromosomal stability. Plant Cell : 24(3), 1171-1187. (IF 10,5)
Prof. Dr. Anne-Catherine Schmit, Head of the subproject
Louis-Thibault Corbin, technician