A microRNA-transcription factor module regulates lateral organ size and patterning in Arabidopsis
A microRNA-transcription factor module regulates lateral organ size and patterning in Arabidopsis
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DOI：
10.1111/j.1365-313x.2009.03796.x
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发表时间：
2009-05-01
期刊：
影响因子：
7.2
通讯作者：
Walker, John C.
中科院分区：
文献类型：
--
作者：
Larue, Clayton T.;Wen, Jiangqi;Walker, John C.
精确的调控机制对于正确控制植物侧生器官的扩大和形成是必要的。然而，我们对管理这两个过程的监管模块的理解是有限的。植物发育中的一个新兴主题是微小RNA（miRNA）介导的转录因子的基因调控，包括几个NAC结构域家族成员，如杯形子叶2（CUC 2）。我们发现了一个新的等位基因CUC 2，cuc 2 -1D，揭示了重要的功能，miRNA和CUC 2的调控模块控制横向器官的扩大和图案。cuc 2 -1D在CUC 2 miRNA靶位点携带单点突变，破坏了miRNA靶向。CUC 2和其靶向miRNA miRNA 164之间的紧密平衡被破坏，导致CUC 2 mRNA的过度积累和CUC 2表达结构域的扩增。cuc 2 -1D植株相对于野生型植株具有增大的营养和生殖侧器官。从机制上讲，这些扩大的器官是由于相对于野生型，在较长的发育时间框架内发生的细胞增殖增加所致。这种器官增大依赖于受体样激酶ERECTA（ER）。cuc 2 -1D中的这种和侧向器官模式表型表明，miRNA 164和CUC 2是这两个过程的关键调节因子。因此，我们认为miRNA 164和CUC 2形成了一个中央调控模块，作为一个总督的横向器官的模式和扩展。
Precise regulatory mechanisms are necessary to properly control the enlargement and patterning of plant lateral organs. However, our understanding of the regulatory modules that govern both of these processes is limited. An emerging theme in plant development is microRNA (miRNA)-mediated gene regulation of transcription factors, including several NAC domain family members such as CUP-SHAPED COTYLEDON2 (CUC2). We uncovered a novel allele of CUC2, cuc2-1D, that revealed important functions of miRNAs and CUC2 in a regulatory module governing lateral organ enlargement and patterning. cuc2-1D carried a single point mutation in the CUC2 miRNA target site, disrupting miRNA targeting. Disruption of the tight balance between CUC2 and its targeting miRNA, miRNA164, led to over-accumulation of CUC2 mRNA and expansion of the CUC2 expression domain. cuc2-1D plants had enlarged vegetative and reproductive lateral organs relative to wild-type plants. Mechanistically, these enlarged organs resulted from an increase in cell proliferation that occurred over a longer developmental time frame relative to wild-type. This organ enlargement was dependent on the receptor-like kinase, ERECTA (ER). This and lateral organ patterning phenotypes in cuc2-1D suggest that miRNA164 and CUC2 are critical regulators of both processes. Therefore, we propose that miRNA164 and CUC2 form a central regulatory module that acts as a governor of lateral organ patterning and expansion.