Arabidopsis thaliana subclass I ACTIN DEPOLYMERIZING FACTORs and vegetative ACTIN2/8 are novel regulators of endoreplication
Arabidopsis thaliana subclass I ACTIN DEPOLYMERIZING FACTORs and vegetative ACTIN2/8 are novel regulators of endoreplication
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DOI：
10.1007/s10265-021-01333-0
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发表时间：
2021-07-19
影响因子：
2.8
通讯作者：
Umeda, Masaaki
中科院分区：
文献类型：
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作者：
Inada, Noriko;Takahashi, Naoki;Umeda, Masaaki
胞内复制是一种细胞周期，其中基因组复制在没有有丝分裂的情况下发生。通过核内复制增加倍性水平通常与细胞增大和增强的植物生长有关。在这里，我们报告拟南芥亚类I肌动蛋白解聚因子（ADF）和营养型肌动蛋白2/8作为新的内复制调节因子。A. thaliana有11个ADF成员，分为4个亚类。亚类I由四个成员组成，即ADF 1、ADF 2、ADF 3和ADF 4，它们都在各种组织中组成型表达。我们发现，adf 4基因敲除突变体和转基因植物中的所有四个亚类I ADF的表达被抑制（ADF 1 - 4 Ri）表现出增加的成熟的第一叶，这是与表皮铺装细胞面积显着增加的叶面积。倍性分析表明，ADF 1 - 4 Ri成熟叶片的倍性水平显着增加。在adf 4和ADF 1 - 4 Ri的根中以及adf 4的暗生长下胚轴中也观察到增加的倍性。此外，营养体ACT 2和ACT 8的双突变体（act 2/8）表现出成熟叶片的叶面积和倍性水平的增加。因此，肌动蛋白相关通路可以调控核内复制。本文还讨论了肌动蛋白和ADFs调节细胞内复制的可能机制。
Endoreplication is a type of cell cycle where genome replication occurs without mitosis. An increase of ploidy level by endoreplication is often associated with cell enlargement and an enhanced plant growth. Here we report Arabidopsis thaliana subclass I ACTIN DEPOLYMERIZING FACTORs (ADFs) and vegetative ACTIN2/8 as novel regulators of endoreplication. A. thaliana has 11 ADF members that are divided into 4 subclasses. Subclass I consists of four members, ADF1, -2, -3, and -4, all of which constitutively express in various tissues. We found that both adf4 knockout mutant and transgenic plants in which expressions of all of four subclass I ADFs are suppressed (ADF1-4Ri) showed an increased leaf area of mature first leaves, which was associated with a significant increase of epidermal pavement cell area. Ploidy analysis revealed that the ploidy level was significantly increased in mature leaves of ADF1-4Ri. The increased ploidy was also observed in roots of adf4 and ADF1-4Ri, as well as in dark-grown hypocotyls of adf4. Furthermore, double mutants of vegetative ACT2 and ACT8 (act2/8) exhibited an increase of leaf area and ploidy level in mature leaves. Therefore, actin-relating pathway could regulate endoreplication. The possible mechanisms that actin and ADFs regulate endoreplication are discussed.