The regulation of post-germinative transition from the cotyledon- to vegetative-leaf stages by microRNA-targeted SQUAMOSA PROMOTER-BINDING PROTEIN LIKE13 in Arabidopsis
The regulation of post-germinative transition from the cotyledon- to vegetative-leaf stages by microRNA-targeted SQUAMOSA PROMOTER-BINDING PROTEIN LIKE13 in Arabidopsis
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DOI：
10.1017/s0960258510000073
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发表时间：
2010-06-01
影响因子：
2.1
通讯作者：
Nonogaki, Hiroyuki
中科院分区：
文献类型：
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作者：
Martin, Ruth C.;Asahina, Masashi;Nonogaki, Hiroyuki
发芽和早期幼苗发育是植物成功建立林分的关键。萌发后，子叶从种子中长出，子叶来源于胚组织。萌发后的拟南芥幼苗主要由子叶提供营养，直到营养叶出现并开始光合作用。向自养生长的转变是萌发后阶段的一个重要转变。在这里，我们提供的证据表明，下调SQUAMOSA启动子结合蛋白样13（SPL13）的microRNA156（miR156）中起着重要的作用，在调控萌发后开关从子叶阶段到营养叶阶段。在与miR156序列互补的区域中的SPL13序列中产生的沉默突变引起来自miR156的SPL13（mSPL13）mRNA的突变形式的失调。与野生型幼苗相比，突变体幼苗过度积累了miRNA抗性信息，并表现出营养叶出现延迟。在表达非突变的SPL13的对照转基因植物中没有观察到延迟，表明表型是由来自miR156的SPL13的沉默突变和失调特异性引起的。SPL13启动子的特性表明，该基因主要在下胚轴中表达，并影响叶原基发育。这些结果表明miR 156对SPL13的抑制对于拟南芥的正常萌发后生长是必不可少的。
Germination and early seedling development are critical for successful stand establishment of plants. Following germination, the cotyledons, which are derived from embryonic tissue, emerge from the seed. Arabidopsis seedlings at post-germinative stages are supported mainly by the supply of nutrition from the cotyledons until vegetative leaves emerge and initiate photosynthesis. The switch to autotrophic growth is a significant transition at the post-germinative stage. Here, we provide evidence that down-regulation of SQUAMOSA PROMOTER-BINDING PROTEIN LIKE13 (SPL13) by microRNA156 (miR156) plays an important role in the regulation of the post-germinative switch from the cotyledon stage to the vegetative-leaf stage. Silent mutations created in the SPL13 sequence in the region that is complementary to the miR156 sequence caused the deregulation of the mutant form of SPL13 (mSPL13) mRNA from miR156. Mutant seedlings over-accumulated miRNA-resistant messages and exhibited a delay in the emergence of vegetative leaves compared to wild-type seedlings. The delay was not observed in control transgenic plants expressing non-mutated SPL13, indicating that the phenotype was caused specifically by the silent mutations and deregulation of SPL13 from miR156. Characterization of the SPL13 promoter indicated that this gene is expressed mainly in the hypocotyl and affects leaf primordium development. These results suggest that the repression of SPL13 by miR156 is essential for normal post-germinative growth in Arabidopsis.