Prof. Christoph Ringli - Molecular Plant Biology Phytopathology

Every plant cell is surrounded by a cell wall, a matrix mainly composed of interwoven and interacting polysaccharides that produce a strong yet flexible structure. During the growth phase of a cell, the cell wall has to enlarge its surface to allow for the necessary increase in cell volume. Considering the manyfold variations of cell shapes that result from unequal growth of the cell surface, it is obvious that cell growth is not equally distributed but often spatially and temporally restricted. This, in turn, requires a constant flow of information to ascertain the coordination of the different processes in intra- and extracellular compartments that result in proper cell growth. The integrity of the cell wall and its composition must be monitored by a cell wall integrity sensing machinery that relays information on the status of the cell wall to the cell to regulate cell growth. We are studying the process cell wall integrity sensing; specifically, we are investigating the function of Leucine-Rich repeat eXtensin (LRX) proteins, cell wall-localized proteins that are high affinity binding sites of RALFs, peptide hormones that regulate cell growth. In conjunction with RALF peptides, LRXs influence cell wall formation.

We have also an interest in understanding the function of flavonols in cell shape determination. Flavonols are plant metabolites that influence different cell growth processes and modifying flavonol accumulation patterns have striking effects on cell shapes.