Institute of Transformative Bio-Molecules (ITbM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602, Japan.
Department of Plant and Soil Sciences, University of Kentucky, 321 Plant Science Building, 1405 Veterans Dr., Lexington, KY 40546, USA.
J Cell Sci. 2018 Jan 29;131(2):jcs204123. doi: 10.1242/jcs.204123.
Cell fusion is a pivotal process in fertilization and multinucleate cell formation. A plant cell is ubiquitously surrounded by a hard cell wall, and very few cell fusions have been observed except for gamete fusions. We recently reported that the fertilized central cell (the endosperm) absorbs the persistent synergid, a highly differentiated cell necessary for pollen tube attraction. The synergid-endosperm fusion (SE fusion) appears to eliminate the persistent synergid from fertilized ovule in Here, we analyzed the effects of various inhibitors on SE fusion in an culture system. Different from other cell fusions, neither disruption of actin polymerization nor protein secretion impaired SE fusion. However, transcriptional and translational inhibitors decreased the SE fusion success rate and also inhibited endosperm division. Failures of SE fusion and endosperm nuclear proliferation were also induced by roscovitine, an inhibitor of cyclin-dependent kinases (CDK). These data indicate unique aspects of SE fusion such as independence of filamentous actin support and the importance of CDK-mediated mitotic control.
细胞融合是受精和多核细胞形成的关键过程。植物细胞普遍被坚硬的细胞壁包围，除了配子融合外，很少观察到其他细胞融合。我们最近报道称，受精的中央细胞（胚乳）吸收了持久的助细胞，这是一种对花粉管吸引至关重要的高度分化细胞。助细胞-胚乳融合（SE 融合）似乎会将已受精胚珠中的持久助细胞消除。在这里，我们在一个体外培养系统中分析了各种抑制剂对 SE 融合的影响。与其他细胞融合不同，肌动蛋白聚合的破坏或蛋白质分泌的抑制都不会损害 SE 融合。然而，转录和翻译抑制剂降低了 SE 融合的成功率，并抑制了胚乳的分裂。细胞周期蛋白依赖性激酶（CDK）抑制剂 roscovitine 也会导致 SE 融合和胚乳核增殖失败。这些数据表明 SE 融合具有独特的方面，例如不需要丝状肌动蛋白的支持，以及 CDK 介导的有丝分裂控制的重要性。
