Evolution of cellular characteristics is a fundamental aspect of evolutionary biology, but knowledge about evolution at the cellular level is very limited. In particular, whether a certain intracellular characteristic evolved in angiosperms, and what significance of such evolution is to angiosperms, if it exists, are important and yet unanswered questions. We have found that bidirectional cytokinesis occurs or likely occurs in male meiosis in extant basal and near-basal angiosperm lineages, which differs from the unidirectional cytokinesis in male meiosis in monocots and eudicots. This pattern of cytokinesis in angiosperms seems to align with the distribution pattern of angiosperms with the lineages basal to monocots and eudicots living in tropical, subtropical, or temperate environments and monocots and eudicots in an expanded range of environments including tropical, subtropical, temperate, subarctic and arctic environments. These two cytokinetic modes seem to result from two phragmoplast types, respectively. A phragmoplast in the bidirectional cytokinesis dynamically associate with the leading edge of a growing cell plate whereas a phragmoplast in the unidirectional cytokinesis is localized to an entire division plane. The large assembly of microtubules in the phragmoplast in unidirectional cytokinesis may be indicative of increased microtubule stability compared with that of the small microtubule assembly in the phragmoplast in bidirectional cytokinesis. Microtubules could conceivably increase their stability from evolutionary changes in tubulins and/or microtubule-associated proteins. Microtubules are very sensitive to low temperatures, which should be a reason for plants to be sensitive to low temperatures. If monocots and eudicots have more stable microtubules than other angiosperms, they will be expected to deal with low temperatures better than other angiosperms. Future investigations into the male meiotic cytokinetic directions, microtubule stability at low temperatures, and proteins affecting microtubule stability in more species may shed light on how plants evolved to inhabit cold environments.

中文翻译：

---

被子植物雄性减数分裂胞质分裂进化的可能模式

细胞特征的进化是进化生物学的一个基本方面，但关于细胞水平进化的知识非常有限。特别是，某种细胞内特征是否在被子植物中进化，以及这种进化如果存在的话对被子植物有何意义，是重要但尚未解答的问题。我们发现，现存基部和近基部被子植物谱系的雄性减数分裂中发生或可能发生双向胞质分裂，这与单子叶植物和真双子叶植物雄性减数分裂中的单向胞质分裂不同。被子植物中的这种胞质分裂模式似乎与被子植物的分布模式一致，这些谱系具有生活在热带、亚热带或温带环境中的单子叶植物和真双子叶植物的基础谱系，以及生活在包括热带、亚热带、温带、亚北极在内的广泛环境中的单子叶植物和真双子叶植物。和北极环境。这两种细胞因子模式似乎分别由两种成膜体类型产生。双向胞质分裂中的成膜体动态地与生长的细胞板的前缘相关联，而单向胞质分裂中的成膜体定位于整个分裂平面。与双向胞质分裂中成膜体中的小微管组装相比，单向胞质分裂中成膜体中的大微管组装可能表明微管稳定性增加。可以想象，微管可以通过微管蛋白和/或微管相关蛋白的进化变化来提高其稳定性。微管对低温非常敏感，这应该是植物对低温敏感的一个原因。如果单子叶植物和真双子叶植物比其他被子植物具有更稳定的微管，那么它们将有望比其他被子植物更好地应对低温。未来对雄性减数分裂细胞因子方向、低温下微管稳定性以及影响更多物种微管稳定性的蛋白质的研究可能会揭示植物如何进化以适应寒冷环境。