PhD defences at IPS2 during spring/summer 2023
Léa MAUPILÉ
Molecular characterization of fruit set induced by growth regulators in melon
Keywords: parthenocarpy, growth regulators, fruit set
Pollinators decline and global warming threaten flower fertilization success and, thus, fruit production. Parthenocarpy, a fertilization independent fruit set, could be a way to overcome this problem. Fruit set in Cucumis melo, one of the most consumed fruit crops worldwide, is impacted by the pollinators decline and sub-optimal environmental conditions. The goal of my thesis was therefore to investigate cytological and molecular processes associated with fruit set in melon. Tissue-specific transcriptome comparisons of fertilized flowers to chemically induced fruit set enabled to identify key activators and repressors of fruit set. Using two reverse genetics approaches, TILLING and VIGS, we investigated the function of a list of candidate genes and identified promising leads to optimize fruit set in Cucurbits.
PhD defense: July, 10th 2023
PhD co-supervisors: A. Bendahmane and J. Chaïb
Sarah REGNARD
Characterization of an MKK3 module involved in the regulation of seed dormancy in Arabidopsis thaliana
Keywords: parthenocarpy, growth regulators, fruit set
Seed dormancy is a genetic program that optimizes the survival of future seedlings. It entails a temporary and reversible inhibition of germination. The objective of my PhD was to characterize a MAPK (Mitogen Activated Protein Kinase) module involved in the regulation of dormancy in Arabidopsis thaliana. The module I characterized involves MAP3K13/14/19/20, MKK3 and clade-C MAPKs, including MPK7. I demonstrated a strong activation of MPK7 during the emergence of dormancy in response to light and nitrate stimuli. However, MPK7 activation in the map3k13/14/19/20 mutant and mkk3 is significantly reduced, indicating its strong dependence on the upstream transcriptional regulation of MAP3K13/14/19/20 by light or nitrate.
PhD defense: March, 8th 2023
Supervisor: J. Colcombet
18/07/2023