Stem Cell Regulation by Arabidopsis WOX Genes
Stem Cell Regulation by Arabidopsis WOX Genes
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DOI：
10.1016/j.molp.2016.04.007
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发表时间：
2016-07-06
期刊：
影响因子：
27.5
通讯作者：
Laux, Thomas
中科院分区：
文献类型：
--
作者：
Dolzblasz, Alicja;Nardmann, Judith;Laux, Thomas
基因扩增之后的功能多样化是进化的主要力量。一个典型的例子是WUSCHEL相关的HOMEOBOX （WOX）基因家族，以拟南芥干细胞调节剂WUSCHEL命名。这里我们分析了WOX基因家族的功能分化。WUS分支的成员，除形成层细胞调节剂WOX4外，都能不同程度地替代WUS在茎和花干细胞维持中的作用。WUS的干细胞功能需要一个典型的WUS-box，这是与TPL/TPR共抑制因子相互作用所必需的，而抑制性EAR结构域是可有可无的，酸性结构域似乎只需要女性生育能力。与WUS分支相反，古老的WOX13和WOX9分支的成员不能支持干细胞的维持。虽然同源结构域在WUS和WOX9进化分支成员之间是可互换的，但一个与WUS兼容的同源结构域和规范的WUS-box并不足以维持干细胞。我们的研究结果表明，WOX在拟南芥茎部和花分生组织中的功能仅限于现代WUS分支，这表明干细胞控制是一种衍生功能。然而，除了同域和WUS-box之外，尚未发现的功能域对于该功能是必需的。
Gene amplification followed by functional diversification is a major force in evolution. A typical example of this is seen in the WUSCHEL-RELATED HOMEOBOX (WOX) gene family, named after the Arabidopsis stem cell regulator WUSCHEL. Here we analyze functional divergence in the WOX gene family. Members of the WUS clade, except the cambiumstem cell regulator WOX4, can substitute for WUS function in shoot and floral stem cell maintenance to different degrees. Stem cell function of WUS requires a canonical WUS-box, essential for interaction with TPL/TPR co-repressors, whereas the repressive EAR domain is dispensable and the acidic domain seems only to be required for female fertility. In contrast to the WUS clade, members of the ancient WOX13 and the WOX9 clades cannot support stem cell maintenance. Although the homeodomains are interchangeable between WUS and WOX9 clade members, a WUS-compatible homeodomain together with canonical WUS-box is not sufficient for stem cell maintenance. Our results suggest that WOX function in shoot and floral meristems of Arabidopsis is restricted to the modern WUS clade, suggesting that stem cell control is a derived function. Yet undiscovered functional domains in addition to the homeodomain and the WUS-box are necessary for this function.