Cell Wall Integrity and Growth Control in Plant Cells
Growing plant cells direct the deposition of the primary cell wall (CW), a rigid extracellular matrix that yet is flexible enough to allow expansion. To achieve such a remarkable dynamic balance between flexibility and rigidity, the growing cell must be kept informed about any environmental changes modifying its CW properties so as to avoid growth arrest or rupture. To circumvent these catastrophic scenarios, plant cells have developed CW integrity (CWI) mechanisms to coordinate CW performance and the internal growth machinery. Our main interest is to elucidate how this relatively unexplored, complex and fascinating coordination occurs. As an exciting model system to study growth control in a changing environment, and because of its importance for seed production and agriculture, we use pollen tube (PT), the male gametophyte of flowering plants that elongate at amazing speeds to effect fertilization. Our goal is to unravel how the redundant receptor-like kinases ANXUR1 (ANX1) and ANX2 coordinate CW performance and PT growth (see Boisson-Dernier et al., 2009, 2011, 2013, 2015).