Repression of AUXIN RESPONSE FACTOR10 by microRNA160 is critical for seed germination and post-germination stages
Repression of AUXIN RESPONSE FACTOR10 by microRNA160 is critical for seed germination and post-germination stages
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DOI：
10.1111/j.1365-313x.2007.03218.x
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发表时间：
2007-10-01
期刊：
影响因子：
7.2
通讯作者：
Carrington, James C.
中科院分区：
文献类型：
--
作者：
Liu, Po-Pu;Montgomery, Taiowa A.;Carrington, James C.
生长素反应因子（ARF）是植物生长发育过程中参与生长素信号转导的转录因子。ARF10、ARF16和ARF17是拟南芥中microRNA160（miR160）的靶点。在这里，我们表明，ARF10的负调控miR160在种子萌发和萌发后起着重要作用。表达ARF10的miR160抗性形式的转基因植物，其在miRNA靶位点（称为mARF10）中具有沉默突变，表现出发育缺陷，如锯齿状叶，卷曲茎，扭曲花和扭曲长角果。在野生型植物或用靶向ARF10基因转化的植物中未观察到这些表型。在严格意义上的萌发和萌发后，mARF10突变体种子和植物的超敏感阿坝的剂量依赖性的方式。外源生长素在野生型植物中模拟阿坝超敏反应。相反，MIR160（35S：MIR160）的过表达导致发芽过程中对阿坝的敏感性降低。发芽ARF 10和mARF 10种子的转录组分析表明，种子成熟期间表达的典型ABA响应基因在发芽mARF 10种子中过表达。这些结果表明，ARF10的miR160的负调控在种子萌发和胚后发育程序中起着至关重要的作用，至少部分通过涉及ARF10依赖的生长素和阿坝途径之间的相互作用的机制。
AUXIN RESPONSE FACTORS (ARFs) are transcription factors involved in auxin signal transduction during many stages of plant growth development. ARF10, ARF16 and ARF17 are targeted by microRNA160 (miR160) in Arabidopsis thaliana. Here, we show that negative regulation of ARF10 by miR160 plays important roles in seed germination and post-germination. Transgenic plants expressing an miR160-resistant form of ARF10, which has silent mutations in the miRNA target site (termed mARF10), exhibited developmental defects such as serrated leaves, curled stems, contorted flowers and twisted siliques. These phenotypes were not observed in wild-type plants or plants transformed with the targeted ARF10 gene. During sensu stricto germination and post-germination, mARF10 mutant seeds and plants were hypersensitive to ABA in a dose-dependent manner. ABA hypersensitivity was mimicked in wild-type plants by exogenous auxin. In contrast, overexpression of MIR160 (35S:MIR160) resulted in reduced sensitivity to ABA during germination. Transcriptome analysis of germinating ARF10 and mARF10 seeds indicated that typical ABA-responsive genes expressed during seed maturation were overexpressed in germinating mARF10 seeds. These results indicate that negative regulation of ARF10 by miR160 plays a critical role in seed germination and post-embryonic developmental programs, at least in part by mechanisms involving interactions between ARF10-dependent auxin and ABA pathways.