Cleistogamous flowering in barley arises from the suppression of microRNA-guided HvAP2 mRNA cleavage
Cleistogamous flowering in barley arises from the suppression of microRNA-guided HvAP2 mRNA cleavage
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DOI：
10.1073/pnas.0909097107
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发表时间：
2010-01-05
影响因子：
11.1
通讯作者：
Komatsuda, Takao
中科院分区：
文献类型：
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作者：
Nair, Sudha K.;Wang, Ning;Komatsuda, Takao
闭花受精的花在开放前会散发花粉，迫使具有这种习性的植物几乎完全自花受精。闭花受精还提供了一种逃避禾谷类穗枯病感染的手段，并使花粉介导的基因流动最小化。闭花受精大麦浆片萎缩。我们已经分离出clistogamy 1（Cly1）的位置克隆，并显示它编码的转录因子含有两个AP2结构域和一个假定的microRNA miR172靶向位点，这是拟南芥AP2的直系同源物。Cly1的表达集中在浆片原基内。我们在miR172靶向位点的同义核苷酸取代和闭花受精之间建立了完美的关联。由miR172指导的mRNA切割仅在非闭花受精背景中可检测到。我们得出结论，miR172衍生的下调Cly1促进了浆片的发育，从而确保了非闭花受精，尽管miR172靶向位点的单核苷酸变化导致浆片不能正常发育，产生了闭花受精表型。
The cleistogamous flower sheds its pollen before opening, forcing plants with this habit to be almost entirely autogamous. Cleistogamy also provides a means of escape from cereal head blight infection and minimizes pollen-mediated gene flow. The lodicule in cleistogamous barley is atrophied. We have isolated cleistogamy 1 (Cly1) by positional cloning and show that it encodes a transcription factor containing two AP2 domains and a putative microRNA miR172 targeting site, which is an ortholog of Arabidopsis thaliana AP2. The expression of Cly1 was concentrated within the lodicule primordia. We established a perfect association between a synonymous nucleotide substitution at the miR172 targeting site and cleistogamy. Cleavage of mRNA directed by miR172 was detectable only in a noncleistogamous background. We conclude that the miR172-derived down-regulation of Cly1 promotes the development of the lodicules, thereby ensuring noncleistogamy, although the single nucleotide change at the miR172 targeting site results in the failure of the lodicules to develop properly, producing the cleistogamous phenotype.