How cell edges shape plant morphogenesis

Plant morphogenesis relies on tight coordination of genetic, biochemical, and biomechanical processes across different scales. In recent years, the significance of cell edges in the process of morphogenesis has been increasingly recognized. The cell edge domain includes distinct cellular compartments, including the cell wall, plasma membrane, and cytoplasm, all of which can carry specific biochemical hallmarks at their cell edges. The specific geometry of the cell edge furthermore leads to the accumulation of biomechanical stress in growing tissues. These unavoidable biomechanical constraints can lead to cell adhesion and organ-scale morphological defects. An increasing body of evidence highlights that specific mechanisms at cell edges allow plants to cope with such constraints: The activity of several edge-based factors, including cytoskeletal and transport regulators as well as mechanosensors, is essential to preserve tissue and organ integrity. In this review, we will focus on the latest advances regarding the importance of cell edges in shaping plant organ morphogenesis.