Plant fertility defects induced by the enhanced expression of microRNA167

植物荷尔蒙植物生长素在调整植物生长和开发起一个关键作用。最近的进展在植物生长素反应小径的理解被做了，首先由在 Arabidopsis 的植物生长素反应异种的描述。另外， microRNAs (miRNAs ) 被显示了是为正常植物开发和生理学重要的基因的批评管理者。然而，很少对在 miRNAs 并且在正常开发期间的神经质的发信号之间的可能的相互作用被知道。这里，我们显示出那 Arabidopsis microRNA， miR167，有一个互补序列到 AUXIN 反应 FACTOR6 (ARF6 ) 和 ARF8 mRNAs 的部分，能为 ARF8，然而并非为 ARF6 引起抄本降级。我们报导 35S::MIR167b 的 phenotypic 描述转基因的线，和表演转基因的线有的那严重 35S::MIR167b arf6 arf8 的类似于那些的显型加倍异种。转基因的显型建议 miR167 可以镇压在翻译的水平的 ARF6。我们证明转基因的植物在花的机关的所有四锭盘是有缺点的。在转基因的花，细丝是反常地短的，花药不能适当地释放花粉，并且花粉谷物没发芽。我们的结果提供在表明网络支持的基因表示和植物生长素的调停 miRNA 的规章的小径之间的一个重要连接种繁殖开发。

The plant hormone auxin plays a critical role in regulating plant growth and development. Recent advances have been made in the understanding of auxin response pathways, primarily by the characterization of auxin response mutants in Arabidopsis. In addition, microRNAs （miRNAs） have been shown to be critical regulators of genes important for normal plant development and physiology. However, little is known about possible interactions between miRNAs and hormonal signaling during normal development. Here we show that an Arabidopsis microRNA, miR167, which has a complementary sequence to a portion of the A UXINRESPONSE FACTOR6 （ARF6） and ARF8 mRNAs, can cause transcript degradation for ARF8, but not for ARF6. We report phenotypic characterizations of 35S：：MIR167b transgenic lines, and show that severe 35S：：MIR167b transgenic lines had phenotypes similar to those of an arf6 arf8 double mutant. The transgenic phenotypes suggest that miR167 may repress ARF6 at the level of translation. We demonstrate that the transgenic plants are defective in all four whods of floral organs. In the transgenic flowers, filaments were abnormally short, anthers could not properly release pollen, and pollen grains did not germinate. Our results provide an important link between the miRNA-mediated regulatory pathway of gene expression and the auxin signaling network promoting plant reproductive development.