Temporal regulation of shoot development in Arabidopsis thaliana by miR156 and its target SPL3
Temporal regulation of shoot development in Arabidopsis thaliana by miR156 and its target SPL3
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DOI：
10.1242/dev.02521
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发表时间：
2006-09-15
期刊：
影响因子：
4.6
通讯作者：
Poethig, R. Scott
中科院分区：
文献类型：
--
作者：
Wu, Gang;Poethig, R. Scott
SPL3、SPL4 和 SPL5 (SPL3/4/5) 是拟南芥转录因子 SQUAMOSA 启动子结合蛋白样家族密切相关的成员，并且在其 3' UTR 中具有 microRNA miR156 的靶位点。组成型表达 miR156 敏感和 miR156 不敏感形式的 SPL3/4/5 的拟南芥植物的表型表明，所有三个基因都促进营养阶段的变化和开花，并受到 miR156 的强烈抑制。 miR156a 的组成型表达延长了幼年营养性状的表达并延迟开花。这种表型在很大程度上通过 miR156 不敏感形式的 SPL3 的组成型表达得到纠正。幼年向成年的转变伴随着 miR156 水平的下降和 SPL3 mRNA 丰度的增加。仓促对 miR156 和 SPL3 转录本的互补作用，以及 35S::GUS-SPL3 转基因的 miR156 依赖性时间表达模式，表明 miR156 的减少是这一转变期间 SPL3 表达增加的原因。 SPL3 mRNA 通过 ZIPPY/AGO7、RNA 依赖性 RNA 聚合酶 6 (RDR6) 和基因沉默抑制因子 3 (SGS3) 的突变而升高，表明它直接或间接受到 RNAi 的调节。然而，我们的结果表明 RNAi 不会影响该基因的时间表达模式。我们得出的结论是，拟南芥的营养阶段变化是通过 SPL3 表达的增加以及 SPL4 和 SPL5 表达的增加来调节的，并且这种增加是 miR156 水平降低的结果。
SPL3, SPL4 and SPL5 (SPL3/4/5) are closely related members of the SQUAMOSA PROMOTER BINDING PROTEIN-LIKE family of transcription factors in Arabidopsis, and have a target site for the microRNA miR156 in their 3' UTR. The phenotype of Arabidopsis plants constitutively expressing miR156-sensitive and miR156-insensitive forms of SPL3/4/5 revealed that all three genes promote vegetative phase change and flowering, and are strongly repressed by miR156. Constitutive expression of miR156a prolonged the expression of juvenile vegetative traits and delayed flowering. This phenotype was largely corrected by constitutive expression of a miR156-insensitive form of SPL3. The juvenile-to-adult transition is accompanied by a decrease in the level of miR156 and an increase in the abundance of SPL3 mRNA. The complementary effect of hasty on the miR156 and SPL3 transcripts, as well as the miR156-dependent temporal expression pattern of a 35S::GUS-SPL3 transgene, suggest that the decrease in miR156 is responsible for the increase in SPL3 expression during this transition. SPL3 mRNA is elevated by mutations in ZIPPY/AGO7, RNA DEPENDENT RNA POLYMERASE 6 (RDR6) and SUPPRESSOR OF GENE SILENCING 3 (SGS3), indicating that it is directly or indirectly regulated by RNAi. However, our results indicate that RNAi does not contribute to the temporal expression pattern of this gene. We conclude that vegetative phase change in Arabidopsis is regulated by an increase in the expression of SPL3 and probably also SPL4 and SPL5, and that this increase is a consequence of a decrease in the level of miR156.