Regulation of leaf morphology by microRNA394 and its target LEAF CURLING RESPONSIVENESS.
Regulation of leaf morphology by microRNA394 and its target LEAF CURLING RESPONSIVENESS.
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DOI：
10.1093/pcp/pcs080
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发表时间：
2012-07
影响因子：
4.9
通讯作者：
J. Song;S. Huang;T. Dalmay;Z. Yang
中科院分区：
文献类型：
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作者：
J. Song;S. Huang;T. Dalmay;Z. Yang
本研究鉴定了拟南芥miR394及其靶标F-box(Skp1-cullin/CDC53-F-box)基因at1g27340(这里称为卷叶反应，LCR)，用于调控卷叶相关的形态。功能缺失的LCR突变体表现出多效性缺陷，表现为半矮化、叶形改变和茎短。在35S启动子(35S：M5LCR)和靶拟态MIM394下过表达miR394抗性版本的LCR导致叶片卷曲缺陷。相反，高表达35S：MIR394a/b的转基因植株表现为卷叶表型。详细的分析表明，有一定水平的LCR对叶片形态是最佳的，但过低或过高的水平都会导致叶片发育异常，这表明miR394在叶片中的表达是叶片正常形态所必需的。由于植物激素生长素在叶片的形态发生和模式形成中起着至关重要的作用，因此利用DR5-GUS报告基因来监测生长素的反应。我们发现DR5在LCR和35S：：M5LCR中的表达模式与野生型显著不同。此外，LCR在35S：：M5LCR中的过表达显著降低了生长素反应基因IAA3、AXR3和IAMT1的表达，而在35S：：MIR394a中发现这些基因的表达增加。这些结果表明miR394及其靶标LCR参与了叶片发育的调控。
The present study identified Arabidopsis miR394 and its target, an F-box (SKP1-Cullin/CDC53-F-box) gene At1g27340 (here referred to as LEAF CURLING RESPONSIVENESS, LCR), for regulation of leaf curling-related morphology. The loss-of-function lcr mutants exhibit pleiotropic defects with semi-dwarfism, altered leaf shape and a shorter stem. Overexpression of an miR394-resistant version of LCR under the 35S promoter (35S:m5LCR) and target mimicry MIM394 resulted in a curled-down leaf defect. Conversely, transgenic plants overexpressing 35S:MIR394a/b display a curled-up leaf phenotype. Detailed analyses show that there is a certain level of LCR that is optimal for leaf morphology, but lower or higher levels lead to abnormal leaf development, indicating that expression of miR394 in the leaf lamina is necessary for proper leaf morphology. Because the phytohormone auxin plays a crucial role in leaf morphogenesis and patterning, the DR5-GUS reporter gene was used to monitor the auxin response. We show that DR5 expression patterns in lcr and 35S::m5LCR plants were significantly different from those in the wild type. Also, overexpression of LCR in 35S::m5LCR plants drastically decreased the expression of the auxin-responsive genes IAA3, AXR3 and IAMT1, whereas increased expression of the genes was found in 35S::MIR394a plants. These results indicate that miR394 and its target LCR are involved in the regulation of leaf development.