Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
Planta. 2017 Oct;246(4):797-802. doi: 10.1007/s00425-017-2747-z. Epub 2017 Aug 1.
The auxin-brassinosteroid interaction involving the BIN2-ARF-LBD axis plays a key role in temperature-dependent callus formation in Arabidopsis. An extensive web of multiple hormone signaling pathways underlies callus formation. Here, we report that a brassinosteroid (BR) signaling component, BR-INSENSITIVE 2 (BIN2), positively regulates callus formation. The BIN2 kinase promotes transcriptional activities of AUXIN RESPONSE FACTOR 7 (ARF7) and ARF19 and subsequently activates expression of LATERAL ORGAN BOUNDARIES-DOMAIN 16 (LBD16) and LBD29 during callus formation. Consistently, the BIN2 activity is dependent on ARFs in the control of callus formation. Notably, this auxin-BR interaction is particularly relevant in temperature-dependent callus formation. Misexpression of BIN2 and ARFs resulted in the temperature insensitivity of callus formation. These results indicate that the BIN2-ARF-LBD axis plays a key role in temperature-dependent callus formation in Arabidopsis.
生长素-油菜素甾体相互作用涉及 BIN2-ARF-LBD 轴，在拟南芥中温度依赖性愈伤组织形成中起关键作用。广泛的多种激素信号通路网络是愈伤组织形成的基础。在这里，我们报告油菜素甾体（BR）信号成分 BR-不敏感 2（BIN2）正向调节愈伤组织形成。BIN2 激酶促进 AUXIN RESPONSE FACTOR 7（ARF7）和 ARF19 的转录活性，随后在愈伤组织形成过程中激活 LATERAL ORGAN BOUNDARIES-DOMAIN 16（LBD16）和 LBD29 的表达。一致地，BIN2 活性在控制愈伤组织形成中依赖于 ARFs。值得注意的是，这种生长素-BR 相互作用在温度依赖性愈伤组织形成中尤为相关。BIN2 和 ARFs 的过表达导致愈伤组织形成的温度不敏感。这些结果表明 BIN2-ARF-LBD 轴在拟南芥中温度依赖性愈伤组织形成中起关键作用。
