PIF4 and PIF5 Transcription Factors Link Blue Light and Auxin to Regulate the Phototropic Response in Arabidopsis
PIF4 and PIF5 Transcription Factors Link Blue Light and Auxin to Regulate the Phototropic Response in Arabidopsis
复制标题
PIF4 和 PIF5 转录因子将蓝光和生长素联系起来调节拟南芥的向光性反应
DOI：
10.1105/tpc.113.112417
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发表时间：
2013-06-01
期刊：
影响因子：
11.6
通讯作者：
Li, Chuanyou
中科院分区：
文献类型：
--
作者：
Sun, Jiaqiang;Qi, Linlin;Li, Chuanyou
蓝光 (BL) 和生长素对于拟南芥的向光性至关重要。然而，在向光性过程中光与生长素分子连接的机制仍然难以捉摸。在这里，我们报道了 PHYTOCHROME INTERACTING FACTOR4 (PIF4) 和 PIF5 在 BL 传感器 PHOTOTROPIN1 (PHOT1) 的下游发挥作用，负向调节拟南芥的向光性。我们还发现 PIF4 和 PIF5 负向调节生长素信号传导。此外，我们证明 PIF4 通过与启动子中的 G-box (CACGTG) 基序结合，直接激活 AUXIN/INDOLE-3-ACETIC ACID (IAA) 基因 IAA19 和 IAA29 的表达。我们的基因检测表明，IAA19 和 IAA29 与生长素响应因子 7 (ARF7) 发生物理相互作用，足以使 PIF4 负向调节生长素信号传导和向光性。这项研究通过表明 PIF4 和 PIF5 连接光和生长素，确定了拟南芥中向光性信号传导的关键步骤。
Both blue light (BL) and auxin are essential for phototropism in Arabidopsis thaliana. However, the mechanisms by which light is molecularly linked to auxin during phototropism remain elusive. Here, we report that PHYTOCHROME INTERACTING FACTOR4 (PIF4) and PIF5 act downstream of the BL sensor PHOTOTROPIN1 (PHOT1) to negatively modulate phototropism in Arabidopsis. We also reveal that PIF4 and PIF5 negatively regulate auxin signaling. Furthermore, we demonstrate that PIF4 directly activates the expression of the AUXIN/INDOLE-3-ACETIC ACID (IAA) genes IAA19 and IAA29 by binding to the G-box (CACGTG) motifs in their promoters. Our genetic assays demonstrate that IAA19 and IAA29, which physically interact with AUXIN RESPONSE FACTOR7 (ARF7), are sufficient for PIF4 to negatively regulate auxin signaling and phototropism. This study identifies a key step of phototropic signaling in Arabidopsis by showing that PIF4 and PIF5 link light and auxin.