Liu Jiajia, Tian Huiyu, Zhang Mengxin, Sun Yi, Wang Junxia, Yu Qianqian, Ding Zhaojun
The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, Shandong, China.
College of Life Sciences, Liaocheng University, Liaocheng, Shandong, China.
Cell Rep. 2024 Jan 23;43(1):113617. doi: 10.1016/j.celrep.2023.113617. Epub 2023 Dec 26.
In plant roots, the identity of the stem cell niche (SCN) is maintained by an auxin gradient with its maximum in the quiescent center (QC). Optimal levels of auxin signaling are essential for root SCN identity, but the regulatory mechanisms that control this pathway in root are largely unknown. Here, we find that the zinc finger transcription factor sensitive to proton rhizotoxicity 1 (STOP1) regulates root SCN identity by negative feedback of auxin signaling in root tips. Mutation and overexpression of STOP1 both affect QC cell division and distal stem cell differentiation in the root. We find that auxin treatment stabilizes STOP1 via MPK3/6-dependent phosphorylation. Accumulating STOP1 can compete with AUX/IAAs to interact with, and enhance the repressive activity of, auxin-repressive response factor ARF2. Overall, we show that the MPK3/6-STOP1-ARF2 module prevents excessive auxin signaling in the presence of auxin to maintain root SCN identity.
在植物根系中，干细胞龛（SCN）的特性由生长素梯度维持，其最大值位于静止中心（QC）。生长素信号的最佳水平对于根SCN特性至关重要，但控制根中该途径的调控机制在很大程度上尚不清楚。在这里，我们发现对质子根毒性敏感的锌指转录因子1（STOP1）通过根尖生长素信号的负反馈调节根SCN特性。STOP1的突变和过表达均影响根中QC细胞分裂和远端干细胞分化。我们发现生长素处理通过MPK3/6依赖性磷酸化使STOP1稳定。积累的STOP1可以与AUX/IAAs竞争，以与生长素抑制反应因子ARF2相互作用并增强其抑制活性。总体而言，我们表明MPK3/6-STOP1-ARF2模块在生长素存在的情况下防止生长素信号过度，以维持根SCN特性。
