Chromatin assembly factor CAF-1 is required for cellular differentiation during plant development
Chromatin assembly factor CAF-1 is required for cellular differentiation during plant development
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DOI：
10.1242/dev.02599
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发表时间：
2006-11-01
期刊：
影响因子：
4.6
通讯作者：
Hennig, Lars
中科院分区：
文献类型：
--
作者：
Exner, Vivien;Taranto, Patti;Hennig, Lars
染色质组装因子CAF-1在体外促进新复制的DNA上核小体的形成。然而，CAF-1在发育中的作用还知之甚少，因为突变在大多数多细胞模式生物中都不存在。生化证据表明，在拟南芥中，FASCIATA1、FASCIATA2和MSI1形成CAF-1。因为筋膜属突变体是可行的，所以CAF-1不是植物细胞分裂所必需的。拟南芥CAF-1突变体在顶端分生组织中存在缺陷；此外，CAF-1还需要建立幼苗构型、叶片大小和毛状体分化。需要CAF-1来限制丛生叶上的毛状体的分枝。CAF-1突变体中毛状体分枝的增加与核DNA含量的增加并不严格相关。此外，Fas2GLARAPR3双突变体表现出加性遗传互作，表明CAF-1在遗传上与含有GLABRA3的内复制耦合的毛状体分支途径平行。然而，通常需要CAF-1来限制内复制，因为大多数CAF-1突变体的幼苗都增加了倍性。值得注意的是，在Landsberg erecta背景中，CAF-1的丢失并不影响倍性，这表明在一些拟南芥材料中，CAF-1的丢失可以得到补偿。这些结果表明，FAS1、FAS2和MSI1的功能不仅限于分生组织，而且在发育的多个阶段也是控制基因组复制所必需的。
Chromatin assembly factor CAF-1 facilitates the formation of nucleosomes on newly replicated DNA in vitro. However, the role of CAF-1 in development is poorly understood because mutants are not available in most multicellular model organisms. Biochemical evidence suggests that FASCIATA1, FASCIATA2 and MSI1 form CAF-1 in Arabidopsis thaliana. Because fasciata mutants are viable, CAF-1 is not essential for cell division in plants. Arabidopsis CAF-1 mutants have defects in shoot apical meristems; in addition, CAF-1 is required to establish seedling architecture, leaf size and trichome differentiation. CAF-1 is needed to restrict branching of trichomes on rosette leaves. Increased trichome branching in CAF-1 mutants is not strictly correlated with increased nuclear DNA content. In addition, fas2 glabra3 double mutants show an additive genetic interaction, demonstrating that CAF-1 acts genetically parallel to the GLABRA3-containing, endoreduplication-coupled trichome branching pathway. However, CAF-1 is often needed to restrict endoreduplication, because seedlings of most CAF-1 mutants have increased ploidy. Notably, in the Landsberg erecta background, loss of CAF-1 does not affect ploidy, demonstrating that loss of CAF-1 can be compensated in some Arabidopsis accessions. These results reveal that the functions of FAS1, FAS2 and MSI1 are not restricted to meristems, but are also needed to control genome replication at multiple steps of development.