Extracellular Matrix Sensing by FERONIA and Leucine-Rich Repeat Extensins Controls Vacuolar Expansion During Cellular Elongation in Arabidopsis Thaliana

The study explored how FERONIA (FER) and Leucine-Rich Repeat Extensins (LRXs) regulated vacuolar expansion during cellular elongation in Arabidopsis thaliana. It found that the vacuole expanded significantly during cell growth, increasing its occupancy from 30-40% to 80-90% of the cell volume. FER, a receptor-like kinase, and LRX proteins were crucial for sensing cell wall properties and coordinating this expansion. Loss-of-function mutants of FER and LRX showed enlarged vacuoles and resistance to growth inhibitors, indicating their role in the same pathway for extracellular signal sensing and vacuolar regulation. The study suggested that LRX proteins might interact with FER through RALF peptides, with the EXT domain of LRXs being essential for cell wall sensing. These findings linked cell wall stiffness with vacuolar morphology and cellular expansion, highlighting the importance of FER and LRX interactions in plant cell growth.