Abstract text: Maintenance of cell-cell adhesion in plants relies on a dynamic interplay between cell wall composition and growth-generated mechanical forces. Although this relation is essential for understanding tissue integrity, the link between cell wall composition and mechanical stress remains poorly understood.

To address this question, we generated an inducible line that enables controlled modification of pectin, a key cell wall component involved in cell-cell adhesion. Using this system, we captured early molecular, biochemical and biophysical responses that precede the onset of visible cell separation. This system also allowed spatial and dose-dependent control over the severity of cell-cell adhesion loss across different tissues.

Furthermore, we found that localized adhesion loss coincides with specific spatial changes in cell wall compositions and with regions under higher growth-induced mechanical tension. Importantly, pectin depolymerization alone is not enough to disrupt normal cell-cell adhesion when mechanical forces were low. Together, these findings highlight the essential contribution of mechanical forces in modulating cell-cell adhesion and its central role in maintaining tissue integrity in growing tissues.