Diverging from conven2onal cell division models, plant cells engage in incomplete division to establish intercellular communica2on through plasmodesmata. While fundamental for plant mul2cellularity, the mechanisms governing plasmodesmata bridge stabiliza2on, as opposed to severing, remain unknown. We found that the endoplasmic re2culum (ER) play a crucial role in promo2ng incomplete cytokinesis by hindering local abscission events. ER tubes present in contrac2ng cell plate fenestrae create energy barriers stabilizing them. Contrac2on ceases upon encountering a metastable ER-plasma membrane tubular structure, leading to plasmodesmata forma2on. This process relies on the ER-tethers mul2ple C2 domains and transmembrane domain proteins 3, 4, and 6, which act as ER stabilizers, preserving ER posi2on and integrity in nascent bridges. Our findings shade light on the mechanisms through which plants undergo incomplete division to promote intercellular communica2on.