Li Ziqiang P, Moreau Hortense, Petit Jules D, Souza-Moraes Tatiana, Smokvarska Marija, Perez-Sancho Jessica, Petrel Melina, Decoeur Fanny, Brocard Lysiane, Chambaud Clément, Grison Magali, Paterlini Andrea, Glavier Marie, Hoornaert Lucie, Joshi Amit S, Gontier Etienne, Prinz William A, Jaillais Yvon, Taly Antoine, Campelo Felix, Caillaud Marie-Cécile, Bayer Emmanuelle M
bioRxiv. 2024 Oct 14:2023.12.12.571296. doi: 10.1101/2023.12.12.571296.
Diverging from conventional cell division models, plant cells undergo incomplete division to generate plasmodesmata communication bridges between daughter cells. While fundamental for plant multicellularity, the molecular events leading to bridge stabilization, as opposed to severing, remain unknown. Using electron tomography, we mapped the transition from cell plate fenestrae to plasmodesmata. We show that the ER connects daughter cells across fenestrae, and as the cell plate matures, fenestrae contract, causing the PM to mold around constricted ER tubes. The ER's presence prevents fenestrae fusion, forming plasmodesmata, while its absence results in closure. The ER-PM tethers MCTP3, 4, and 6 further stabilize nascent plasmodesmata during fenestrae contraction. Genetic deletion in reduces plasmodesmata formation. Our findings reveal how plants undergo incomplete division to promote intercellular communication.
ONE-SENTENCE SUMMARY: The ER is important for stabilizing nascent plasmodesmata, a process integral to incomplete cytokinesis in plants.
与传统细胞分裂模型不同，植物细胞进行不完全分裂以在子细胞之间生成胞间连丝通讯桥。虽然这对于植物多细胞性至关重要，但导致桥稳定而非切断的分子事件仍不清楚。利用电子断层扫描技术，我们绘制了从细胞板窗孔到胞间连丝的转变过程。我们发现内质网通过窗孔连接子细胞，随着细胞板成熟，窗孔收缩，导致质膜围绕收缩的内质网管成型。内质网的存在阻止窗孔融合，形成胞间连丝，而其缺失则导致关闭。内质网-质膜连接蛋白MCTP3、4和6在窗孔收缩过程中进一步稳定新生的胞间连丝。基因缺失会减少胞间连丝的形成。我们的研究结果揭示了植物如何进行不完全分裂以促进细胞间通讯。
内质网对于稳定新生胞间连丝很重要，这一过程是植物不完全胞质分裂所必需的。
