SCREAM/ICE1 and SCREAM2 specify three cell-state transitional steps leading to Arabidopsis stomatal differentiation
SCREAM/ICE1 and SCREAM2 specify three cell-state transitional steps leading to Arabidopsis stomatal differentiation
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DOI：
10.1105/tpc.108.060848
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发表时间：
2008-07-01
期刊：
影响因子：
11.6
通讯作者：
Torii, Keiko U.
中科院分区：
文献类型：
--
作者：
Kanaoka, Masahiro M.;Pillitteri, Lynn Jo;Torii, Keiko U.
在多细胞生物体中，特化细胞类型的分化需要细胞命运决定因子的协调作用。气孔是植物表皮上的阀门，是由三种密切相关的碱性螺旋环螺旋蛋白SPEECHLESS（SPCH）、MUTE和法马介导的一系列分化事件形成的。然而，不知道是什么机制协调他们的行动。在这里，我们确定了两个旁系同源蛋白，SCREAM（SCRM）和SCRM2，直接相互作用，并指定SPCH，MUTE和法马的顺序动作。SCRM中的功能获得性突变表现出表皮中的组成性气孔分化。相反，SCRM和SCRM2的连续丢失重演了法马，静音，和spch的表型，表明SCRM和SCRM2一起决定气孔细胞谱系的连续启动，增殖和终末分化。我们的研究结果确定了气孔分化的核心调控单位，并提出了一个模型惊人的相似，在动物细胞类型分化。令人惊讶的是，基于图位的克隆显示，SCRM是诱导CBF表达1，一个主调节剂的耐冷冻性，从而暗示了一个潜在的联系之间的转录调节环境适应和发展的植物。
Differentiation of specialized cell types in multicellular organisms requires orchestrated actions of cell fate determinants. Stomata, valves on the plant epidermis, are formed through a series of differentiation events mediated by three closely related basic-helix-loop-helix proteins: SPEECHLESS (SPCH), MUTE, and FAMA. However, it is not known what mechanism coordinates their actions. Here, we identify two paralogous proteins, SCREAM (SCRM) and SCRM2, which directly interact with and specify the sequential actions of SPCH, MUTE, and FAMA. The gain-of-function mutation in SCRM exhibited constitutive stomatal differentiation in the epidermis. Conversely, successive loss of SCRM and SCRM2 recapitulated the phenotypes of fama, mute, and spch, indicating that SCRM and SCRM2 together determined successive initiation, proliferation, and terminal differentiation of stomatal cell lineages. Our findings identify the core regulatory units of stomatal differentiation and suggest a model strikingly similar to cell-type differentiation in animals. Surprisingly, map-based cloning revealed that SCRM is INDUCER OF CBF EXPRESSION1, a master regulator of freezing tolerance, thus implicating a potential link between the transcriptional regulation of environmental adaptation and development in plants.