Plant cytokinesis, a fundamental process of plant life, involves de novo formation of a cell plate that partitions the cytoplasm of the dividing cell. Cell plate formation is directed by orchestrated delivery, fusion of cytokinetic vesicles, and membrane maturation to the form the nascent cell wall by the timely deposition of polysaccharides such as callose, cellulose, and crosslinking glycans. In contrast to the role of endomembrane protein regulators the role of polysaccharides, in cell plate development is poorly understood. Callose, a β-1-3 glucan polymer, is transiently accumulated during cell plate expansion to be replaced by cellulose in mature stages. Based on the severity of cytokinesis defects in the absence of callose, it has been proposed that it stabilizes this membrane network structure. However, there is currently no theory to understand its role in cytokinesis. Here we extend the Helfrich free energy model for membranes including a phenomenological spreading force as an ″areal pressure ″ generated by callose and/or other polysaccharides. Regular cell plate development in the model is possible, with suitable bending modulus, for a two-dimensional late stage spreading force parameter of between 2-6pN/nm; an osmotic pressure difference of 2-10kPa, and spontaneous curvature between 0-0.04nm ^-1. With these conditions, stable membrane conformation sizes and morphologies emerge in concordance with stages of cell plate development. With no spreading force, the cell plate fails to mature properly, corroborating experimental observations of cytokinesis arrest in the absence of callose. To reach a nearly mature cell plate, our model requires the late stage onset that the spreading force coupled with a concurrent loss of spontaneous curvature. A simple model based upon production of callose as a quasi-two-dimensional self-avoiding polymer produces the correct phenomenological form of the spreading force, which will be further refined, since matching to our numbers requires an exceptionally high callose synthesis rate.

中文翻译：

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植物细胞板发育的生物物理模型

植物胞质分裂是植物生命的基本过程，涉及从头形成重新划分分裂细胞胞质的细胞板。细胞板的形成是通过精心安排的递送，细胞动力学囊泡的融合以及膜成熟（通过及时沉积多糖，例如call质，纤维素和交联聚糖）来形成新生细胞壁来控制的。与内膜蛋白调节剂的作用相反，多糖在细胞板发育中的作用知之甚少。β-1-3葡聚糖聚合物质在细胞板扩增过程中短暂积累，在成熟阶段被纤维素替代。基于在没有of的情况下胞质分裂缺陷的严重性，已提出其使该膜网络结构稳定。然而，目前尚无理论来了解其在胞质分裂中的作用。在这里，我们扩展了膜的Helfrich自由能模型，该模型包括由call糖和/或其他多糖产生的“面积压力”的现象学扩散力。在2-6pN / nm之间的二维后期扩展力参数下，在适当的弯曲模量下，模型中的规则孔板发展是可能的。渗透压差为2-10kPa，自发曲率在0-0.04nm之间 对于2-6pN / nm之间的二维后期扩展力参数；渗透压差为2-10kPa，自发曲率在0-0.04nm之间 对于2-6pN / nm之间的二维后期扩展力参数；渗透压差为2-10kPa，自发曲率在0-0.04nm之间 ^-1。在这些条件下，稳定的膜构象大小和形态与细胞板发育阶段一致。没有铺展力，细胞板就无法正常成熟，从而证实了在没有of的情况下细胞分裂停滞的实验观察。为了达到接近成熟的细胞板，我们的模型需要晚期发作，即扩散力加上并发的自发弯曲。一个简单的模型以production糖为准二维自规避聚合物的产生为基础，可以产生正确的现象学形式的扩散力，由于与我们的数量相匹配需要极高的call糖合成速率，因此将进一步完善。