Auxin-regulated chromatin switch directs acquisition of flower primordium founder fate.
Auxin-regulated chromatin switch directs acquisition of flower primordium founder fate.
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DOI：
10.7554/elife.09269
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发表时间：
2015-10-13
期刊：
影响因子：
7.7
通讯作者：
Wagner D
中科院分区：
文献类型：
--
作者：
Wu MF;Yamaguchi N;Xiao J;Bargmann B;Estelle M;Sang Y;Wagner D
在发育过程中细胞身份的重编程经常需要染色质状态的变化，这些变化需要限制在正确的细胞群中。在这里，我们确定了一个生长素酶调节的染色质状态开关，指导重编程从运输扩增到原基创始人细胞的命运在拟南芥花序。在生长素感应后，单翅目转录因子募集SWI/SNF染色质重塑ATP酶以增加DNA的可接近性，用于诱导花原基起始的关键调节因子。在缺乏激素的情况下，生长素敏感的Aux/IAA蛋白结合到MONOPTEROS块招聘的SWI/SNF染色质重塑ATP酶除了招聘一个辅阻遏物/组蛋白脱乙酰酶复合物。这种简单而优雅的细胞分裂素介导的染色质状态转换非常适合于反复的花原基起始，并协调额外的生长素调节的细胞命运转换。我们的研究结果建立了一个新的范式核反应生长素。他们还解释了这种小分子如何指导植物的不同反应。DOI：http://dx.doi.org/10.7554/eLife.09269.001植物在其一生中随着发育和生长而形成新的结构，如花朵或树枝。然而，大多数植物细胞不能产生新的花或分支，因为参与这些过程的基因通常被关闭。这些基因存在于染色质的区域中，染色质是DNA在植物细胞中包装的结构，通常是紧密包装的。这种包装阻止了其他被称为转录因子的蛋白质进入DNA并启动基因。新的花朵由含有高水平植物激素生长素的细胞形成。在这些细胞中，一种名为MONOPTEROS的蛋白质开启了与开花有关的基因。围绕这些基因的染色质结构是如何改变的，从而使它们能够被打开，这一点尚不清楚。Wu，Yamaguchi，Xiao等人在一种被称为拟南芥的植物中研究了这个问题。实验表明，单翅目在改变染色质结构以允许花形成方面起着至关重要的作用。在高水平的生长素的存在下，MONOPTEROS招募称为SWI/SNF重塑复合物的蛋白质组到含有与花形成有关的基因的染色质区域。这些蛋白质复合物使染色质的结构松散，因此基因可以被转录因子打开。Wu，Yamaguchi，Xiao等的研究结果表明，生长素，在MONOPTEROS和SWI/SNF重塑复合物的帮助下，通过改变染色质状态使花形成。他们进一步表明，这种染色质状态转换也参与了叶片的形成和植物中由单翅目和生长素控制的其他过程。DOI：http://dx.doi.org/10.7554/eLife.09269.002
Reprogramming of cell identities during development frequently requires changes in the chromatin state that need to be restricted to the correct cell populations. Here we identify an auxin hormone-regulated chromatin state switch that directs reprogramming from transit amplifying to primordium founder cell fate in Arabidopsis inflorescences. Upon auxin sensing, the MONOPTEROS transcription factor recruits SWI/SNF chromatin remodeling ATPases to increase accessibility of the DNA for induction of key regulators of flower primordium initiation. In the absence of the hormonal cue, auxin sensitive Aux/IAA proteins bound to MONOPTEROS block recruitment of the SWI/SNF chromatin remodeling ATPases in addition to recruiting a co-repressor/histone deacetylase complex. This simple and elegant hormone-mediated chromatin state switch is ideally suited for iterative flower primordium initiation and orchestrates additional auxin-regulated cell fate transitions. Our findings establish a new paradigm for nuclear response to auxin. They also provide an explanation for how this small molecule can direct diverse plant responses. DOI: http://dx.doi.org/10.7554/eLife.09269.001 Plants form new structures such as flowers or branches throughout their life as they develop and grow. However, most plant cells are not able to produce a new flower or branch because the genes involved in these processes are usually switched off. The genes are found in regions of chromatin—the structure in which DNA is packaged in plant cells—that are normally tightly packed. This packing prevents other proteins called transcription factors from accessing the DNA and switching the genes on. New flowers form from cells that contain high levels of a plant hormone called auxin. In these cells, a protein called MONOPTEROS switches on genes involved in making flowers. How the structure of the chromatin that surrounds these genes is altered so that they can be switched on is not clear. Wu, Yamaguchi, Xiao et al. studied this question in a plant known as Arabidopsis. The experiments show that MONOPTEROS plays a crucial role in altering the structure of chromatin to allow flowers to form. In the presence of high levels of auxin, MONOPTEROS recruits groups of proteins called SWI/SNF remodeling complexes to regions of chromatin that contain genes involved in flower formation. These protein complexes loosen the structure of the chromatin so that genes can be switched on by transcription factors. Wu, Yamaguchi, Xiao et al.'s findings suggest that auxin, with the help of MONOPTEROS and the SWI/SNF remodeling complexes, enables flower formation by changing the chromatin state. They further suggest that this chromatin state switch is also involved in leaf formation and other processes in plants that are controlled by MONOPTEROS and auxin. DOI: http://dx.doi.org/10.7554/eLife.09269.002