The microRNA167 controls somatic embryogenesis in Arabidopsis through regulating its target genes ARF6 and ARF8
The microRNA167 controls somatic embryogenesis in Arabidopsis through regulating its target genes ARF6 and ARF8
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DOI：
10.1007/s11240-015-0903-3
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发表时间：
2016-02-01
影响因子：
3
通讯作者：
Zhang, Xian Sheng
中科院分区：
文献类型：
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作者：
Su, Ying Hua;Liu, Yu Bo;Zhang, Xian Sheng
microRNA（miRNAs）是一类内源性的小分子单链RNA，能够下调植物和动物的基因表达。已知植物miRNA通过靶向mRNA降解或抑制而在植物发育期间的许多生物学过程中起作用。体细胞胚胎发生是研究与胚胎发生相关的miRNAs的一个模型，也是植物繁殖的一个重要途径。为了确定miRNA在拟南芥体细胞胚胎发生中的作用，我们分析了体细胞胚胎（SE）诱导前后胚性愈伤组织中已知miRNA的miRNA微阵列。在从微阵列数据中鉴定出几种差异表达的miRNAs后，我们将重点放在编码miR 167的MIR 167 c上，因为它可能参与SE诱导。miR 167的过表达抑制SE形成，表明miR 167负调节SE诱导。miR 167对SE形成的负面影响的特征在于改变了胚性愈伤组织中生长素的响应和局部生长素的运输。miR 167的过表达导致低水平的生长素反应因子6（ARF 6）和ARF 8转录物。遗传分析显示arf 6和arf 8单突变体和arf 6 -2 arf 8 -3/+倍半突变体显示SE缺陷。因此，我们的研究结果表明，miR 167通过生长素信号组分ARF 6和ARF 8调节体细胞胚胎发生。本研究为miRNA介导的体细胞胚胎发生提供了重要信息。
MicroRNAs (miRNAs) are single-stranded small, endogenous RNAs that can downregulate gene expression in plants and animals. Plant miRNAs are already known to function in many biological processes during plant development by targeting mRNA for degradation or repression. Somatic embryogenesis is used as a model to investigate miRNAs associated with embryogenesis and also as an important pathway for plant propagation. To determine the roles of miRNAs in Arabidopsis somatic embryogenesis, we analyzed miRNA microarrays representing known miRNAs in embryonic callus before and after somatic embryo (SE) induction. After identifying several differentially expressed miRNAs from the microarray data, we focused on MIR167c encoding miR167 because of its potential involvement in SE induction. Overexpression of miR167 inhibited SE formation, showing that miR167 negatively regulates SE induction. The negative effects of miR167 on SE formation are characterized by the alteration of auxin response and local auxin transport in embryonic callus. Overexpression of miR167 resulted in low levels of auxin response factor 6 (ARF6) and ARF8 transcripts. Genetic analysis revealed that arf6 and arf8 single mutants and the arf6-2 arf8-3/+ sesquimutant displayed SE defects. Our results thus suggest that miR167 regulates somatic embryogenesis through auxin signaling components ARF6 and ARF8. This study provides important information concerning miRNA-mediated somatic embryogenesis.