The Plant Resilience Institute, Michigan State University, East Lansing, MI 48824, USA; Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, USA.
Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA.
Curr Biol. 2023 May 8;33(9):1778-1786.e5. doi: 10.1016/j.cub.2023.03.005. Epub 2023 Mar 23.
Nutrient sensing and signaling are essential for adjusting growth and development to available resources. Deprivation of the essential mineral phosphorus (P) inhibits root growth. The molecular processes that sense P limitation to trigger early root growth inhibition are not known yet. Target of rapamycin (TOR) kinase is a central regulatory hub in eukaryotes to adapt growth to internal and external nutritional cues. How nutritional signals are transduced to TOR to control plant growth remains unclear. Here, we identify Arabidopsis-root-specific kinase 1 (ARSK1), which attenuates initial root growth inhibition in response to P limitation. We demonstrate that ARSK1 phosphorylates and stabilizes the regulatory-associated protein of TOR 1B (RAPTOR1B), a component of the TOR complex 1, to adjust root growth to P availability. These findings uncover signaling components acting upstream of TOR to balance growth to P availability.
营养感应和信号传递对于根据可用资源来调节生长和发育至关重要。必需矿物质磷（P）的缺乏会抑制根的生长。然而，目前尚不清楚感知 P 限制以触发早期根生长抑制的分子过程。雷帕霉素靶蛋白（TOR）激酶是真核生物中适应内部和外部营养线索的核心调节枢纽。营养信号如何被转导到 TOR 以控制植物生长仍不清楚。在这里，我们鉴定出拟南芥根特异性激酶 1（ARSK1），它可减轻对 P 限制的初始根生长抑制。我们证明 ARSK1 磷酸化并稳定 TOR 复合物 1 的调节相关蛋白 1B（RAPTOR1B），该蛋白是 TOR 复合物 1 的一个组成部分，以调节根生长对 P 可用性的响应。这些发现揭示了作用于 TOR 上游的信号传导成分，以平衡生长对 P 可用性的需求。
