Regulation of flowering time and floral organ identity by a microRNA and its APETALA2-like target genes
Regulation of flowering time and floral organ identity by a microRNA and its APETALA2-like target genes
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DOI：
10.1105/tpc.016238
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发表时间：
2003-11-01
期刊：
影响因子：
11.6
通讯作者：
Sakai, H
中科院分区：
文献类型：
--
作者：
Aukerman, MJ;Sakai, H
MicroRNAs(MiRNAs)类似于已在动物和植物中发现的21个核苷酸的非编码RNA。虽然在动物中有直接证据表明特定的miRNAs参与控制发育时机，但到目前为止，还不知道植物miRNAs是否也在调节时间转换方面发挥作用。通过激活标签的方法，我们证明了miRNA172(MiR172)在拟南芥中过表达时会导致早花并扰乱花器官特征的指定。MiR172通常以时间方式表达，与其在开花时间控制中的作用一致。MiR172的调控靶点是APETALA2(AP2)转录因子基因的一个亚家族。我们提出的证据表明，miR172通过翻译机制而不是RNA切割下调这些靶基因的表达。功能获得和功能丧失分析表明，两个AP2样靶基因通常作为花抑制因子，支持miR172通过下调AP2样靶基因来调节开花时间的观点。
MicroRNAs (miRNAs) are similar to21-nucleotide noncoding RNAs that have been identified in both animals and plants. Although in animals there is direct evidence implicating particular miRNAs in the control of developmental timing, to date it is not known whether plant miRNAs also play a role in regulating temporal transitions. Through an activation-tagging approach, we demonstrate that miRNA 172 (miR172) causes early flowering and disrupts the specification of floral organ identity when overexpressed in Arabidopsis. miR172 normally is expressed in a temporal manner, consistent with its proposed role in flowering time control. The regulatory target of miR172 is a subfamily of APETALA2 (AP2) transcription factor genes. We present evidence that miR172 downregulates these target genes by a translational mechanism rather than by RNA cleavage. Gain-of-function and loss-of-function analyses indicate that two of the AP2-like target genes normally act as floral repressors, supporting the notion that miR172 regulates flowering time by downregulating AP2-like target genes.