SMAX1 增强了光敏色素 B 介导的下胚轴热形态发生。
SMAX1 potentiates phytochrome B-mediated hypocotyl thermomorphogenesis.
机构信息
Department of Chemistry, Seoul National University, Seoul 08826, Korea.
Plant Genomics and Breeding Institute, Seoul National University, Seoul 08826, Korea.
出版信息
Plant Cell. 2022 Jul 4;34(7):2671-2687. doi: 10.1093/plcell/koac124.
Plant thermosensors help optimize plant development and architecture for ambient temperatures, and morphogenic adaptation to warm temperatures has been extensively studied in recent years. Phytochrome B (phyB)-mediated thermosensing and the gene regulatory networks governing thermomorphogenic responses are well understood at the molecular level. However, it is unknown how plants manage their responsiveness to fluctuating temperatures in inducing thermomorphogenic behaviors. Here, we demonstrate that SUPPRESSOR OF MAX2 1 (SMAX1), known as a karrikin signaling repressor, enhances the thermosensitivity of hypocotyl morphogenesis in Arabidopsis thaliana. Hypocotyl thermomorphogenesis was largely disrupted in SMAX1-deficient mutants. SMAX1 interacts with phyB to alleviate its suppressive effects on the transcription factor activity of PHYTOCHROME-INTERACTING FACTOR 4 (PIF4), promoting hypocotyl thermomorphogenesis. Interestingly, the SMAX1 protein is slowly destabilized at warm temperatures, preventing hypocotyl overgrowth. Our findings indicate that the thermodynamic control of SMAX1 abundance serves as a molecular gatekeeper for phyB function in thermosensitizing PIF4-mediated hypocotyl morphogenesis.
植物热传感器有助于优化植物在环境温度下的发育和结构，近年来，人们对植物适应温暖温度的形态发生适应性进行了广泛的研究。植物色素 B（phyB）介导的热感应和调控热形态发生反应的基因调控网络在分子水平上得到了很好的理解。然而，目前尚不清楚植物如何在诱导热形态发生行为时管理其对波动温度的反应性。在这里，我们证明了 SUPPRESSOR OF MAX2 1（SMAX1），作为一种卡瑞卡丁信号抑制剂，增强了拟南芥下胚轴形态发生的热敏感性。SMAX1 缺陷突变体中的下胚轴热形态发生受到严重破坏。SMAX1 与 phyB 相互作用，减轻其对转录因子 PHYTOCHROME-INTERACTING FACTOR 4（PIF4）活性的抑制作用，促进下胚轴热形态发生。有趣的是，SMAX1 蛋白在温暖温度下缓慢失稳，防止下胚轴过度生长。我们的研究结果表明，SMAX1 丰度的热力学控制是 phyB 功能在热敏感 PIF4 介导的下胚轴形态发生中的分子门控。
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