The WOX13 homeobox gene promotes replum formation in the Arabidopsis thaliana fruit
The WOX13 homeobox gene promotes replum formation in the Arabidopsis thaliana fruit
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DOI：
10.1111/tpj.12010
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发表时间：
2013-01-01
期刊：
影响因子：
7.2
通讯作者：
Pelaz, Soraya
中科院分区：
文献类型：
--
作者：
Romera-Branchat, Maida;Ripoll, Juan Jose;Pelaz, Soraya
拟南芥的果实由受精卵雌蕊发育成种荚。它主要由卵巢组成，其中可以分化出三种不同的组织：瓣膜、瓣膜边缘和复肠。瓣叶边缘细胞的分离使瓣叶能与复顶体分离，从而使种子扩散。瓣和瓣缘位于外侧位置，而复瓣位于中间位置，并保留类似于茎尖分生组织（SAM）的分生组织特性。wuschell相关homeobox家族成员参与了SAM的干细胞维持，在该家族中，我们发现WOX13主要表达于分生组织，包括直肠。我们还发现，wox13功能缺失突变减少了补液大小，并增强了补液识别基因RPL中受影响的突变体的表型。相反，与BP和RPL无关，WOX13的错误表达会产生一个超大的补孔和瓣膜缺陷，与JAG/FIL活性基因突变体非常相似。我们的研究结果表明，WOX13可能通过阻止内侧组织中JAG/FIL基因的活性来促进补液发育。这种调控似乎在建立JAG/FIL活性沿果实中外侧轴的梯度中起作用，这对正确的图案形成至关重要。我们的数据使我们能够将WOX13的作用纳入协调果实图案的调节网络中。
The Arabidopsis fruit forms a seedpod that develops from the fertilized gynoecium. It is mainly comprised of an ovary in which three distinct tissues can be differentiated: the valves, the valve margins and the replum. Separation of cells at the valve margin allows for the valves to detach from the replum and thus dispersal of the seeds. Valves and valve margins are located in lateral positions whereas the replum is positioned medially and retains meristematic properties resembling the shoot apical meristem (SAM). Members of the WUSCHEL-related homeobox family have been involved in stem cell maintenance in the SAM, and within this family, we found that WOX13 is expressed mainly in meristematic tissues including the replum. We also show that wox13 loss-of-function mutations reduce replum size and enhance the phenotypes of mutants affected in the replum identity gene RPL. Conversely, misexpression of WOX13 produces, independently from BP and RPL, an oversized replum and valve defects that closely resemble those of mutants in JAG/FIL activity genes. Our results suggest that WOX13 promotes replum development by likely preventing the activity of the JAG/FIL genes in medial tissues. This regulation seems to play a role in establishing the gradient of JAG/FIL activity along the medio-lateral axis of the fruit critical for proper patterning. Our data have allowed us to incorporate the role of WOX13 into the regulatory network that orchestrates fruit patterning.