Prizes given to Chiara Auwerx and Francesca Mattioli (May 2024)

Chiara Auwerx and Francesca Mattioli were awarded the best and the runners-up awards for best presentation at the Swiss Society of Medical Genetics annual meeting (May 16-17, 2024, Bern) for their “Rare copy-number variants as modulators of common disease susceptibility” and “Bi-allelic variants in BRF2 are associated with perinatal death and craniofacial anomalies” talks, respectively.

Welcome Lise!

Hello everyone,

My name is Lise Rolée and I recently started as an Administrative Assistant. I will be in charge of the groups of Alexandre Reymond, Richard Benton, Johannes Larsch and Jean-Yves Roignant.

I worked for 6 years in the Department of Fundamental Neurosciences in the same position, where I learned a lot. I’m happy to be able to share it with you!

I’m looking forward to meeting you all,

Plant Direct. auth.: Group Fankhauser

Pectin methylesterification state and cell wall mechanical properties contribute to neighbor proximity-induced hypocotyl growth in Arabidopsis

Fabien Sénéchal 1 2Sarah Robinson 3 4Evert Van Schaik 5 6Martine Trévisan 1Prashant Saxena 1 7Didier Reinhardt 5Christian Fankhauser 1

. 2024 Apr 21;8(4):e584.

 doi: 10.1002/pld3.584. eCollection 2024 Apr.

Abstract

Plants growing with neighbors compete for light and consequently increase the growth of their vegetative organs to enhance access to sunlight. This response, called shade avoidance syndrome (SAS), involves photoreceptors such as phytochromes as well as phytochrome interacting factors (PIFs), which regulate the expression of growth-mediating genes. Numerous cell wall-related genes belong to the putative targets of PIFs, and the importance of cell wall modifications for enabling growth was extensively shown in developmental models such as dark-grown hypocotyl. However, the contribution of the cell wall in the growth of de-etiolated seedlings regulated by shade cues remains poorly established. Through analyses of mechanical and biochemical properties of the cell wall coupled with transcriptomic analysis of cell wall-related genes from previously published data, we provide evidence suggesting that cell wall modifications are important for neighbor proximity-induced elongation. Further analysis using loss-of-function mutants impaired in the synthesis and remodeling of the main cell wall polymers corroborated this. We focused on the cgr2cgr3 double mutant that is defective in methylesterification of homogalacturonan (HG)-type pectins. By following hypocotyl growth kinetically and spatially and analyzing the mechanical and biochemical properties of cell walls, we found that methylesterification of HG-type pectins was required to enable global cell wall modifications underlying neighbor proximity-induced hypocotyl growth. Collectively, our work suggests that plant competition for light induces changes in the expression of numerous cell wall genes to enable modifications in biochemical and mechanical properties of cell walls that contribute to neighbor proximity-induced growth.