Deregulation of the OsmiR160 Target Gene OsARF18 Causes Growth and Developmental Defects with an Alteration of Auxin Signaling in Rice.
Deregulation of the OsmiR160 Target Gene OsARF18 Causes Growth and Developmental Defects with an Alteration of Auxin Signaling in Rice.
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DOI：
10.1038/srep29938
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发表时间：
2016-07-21
影响因子：
4.6
通讯作者：
Zhao D
中科院分区：
文献类型：
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作者：
Huang J;Li Z;Zhao D
MicroRNAs(MiRNAs)在转录后水平上作为关键的负调控因子控制基因的表达。MiR160通过抑制其目标生长素反应因子(ARF)基因的表达而在拟南芥的生长发育中发挥关键作用，然而miR160在单子叶植物中的功能仍不清楚。在本研究中，我们发现成熟水稻miR160(OsmiR160)主要来源于OsMIR160a和OsMIR160b基因。在4个潜在的OsmiR160靶基因中，OsARF18转录本在OsmiR160靶点被切割。转OsARF18基因水稻植株(命名为mOsARF18)表现出生长发育的多效性缺陷，包括矮秆、卷叶和小种子。MOsARF18叶片泡状细胞分化和表皮细胞分裂异常。MOsARF18种子中的淀粉积累也受到了抑制。此外，生长素诱导了OsMIR160a、OsMIR160b和OsARF18的表达，而OsMIR160a和OsMIR160b以及生长素信号转导相关基因的表达发生了变化。我们的结果表明，OsmiR160对OsARF18表达的负调控通过影响生长素信号而对水稻的生长发育起关键作用，这将促进对miR160微调植物生长素信号的分子机制的研究。
MicroRNAs (miRNAs) control gene expression as key negative regulators at the post-transcriptional level. MiR160 plays a pivotal role in Arabidopsis growth and development through repressing expression of its target AUXIN RESPONSE FACTOR (ARF) genes; however, the function of miR160 in monocots remains elusive. In this study, we found that the mature rice miR160 (OsmiR160) was mainly derived from OsMIR160a and OsMIR160b genes. Among four potential OsmiR160 target OsARF genes, the OsARF18 transcript was cleaved at the OsmiR160 target site. Rice transgenic plants (named mOsARF18) expressing an OsmiR160-resistant version of OsARF18 exhibited pleiotropic defects in growth and development, including dwarf stature, rolled leaves, and small seeds. mOsARF18 leaves were abnormal in bulliform cell differentiation and epidermal cell division. Starch accumulation in mOsARF18 seeds was also reduced. Moreover, auxin induced expression of OsMIR160a, OsMIR160b, and OsARF18, whereas expression of OsMIR160a and OsMIR160b as well as genes involved in auxin signaling was altered in mOsARF18 plants. Our results show that negative regulation of OsARF18 expression by OsmiR160 is critical for rice growth and development via affecting auxin signaling, which will advance future studies on the molecular mechanism by which miR160 fine-tunes auxin signaling in plants.