Type-B ARABIDOPSIS RESPONSE REGULATORs Specify the Shoot Stem Cell Niche by Dual Regulation of WUSCHEL

作者：Wen Jing Meng, Zhi Juan Cheng, Ya Lin Sang, Miao Miao Zhang, Xiao Rong, Zhi Wei Wang, Ying Ying Tang, Xian Sheng Zhang · 发表于：The Plant Cell · 年份：2017 · DOI：10.1105/tpc.16.00640 · 被引用次数：334 · 研究领域：Plant Molecular Biology Research、Plant tissue culture and regeneration、Plant Reproductive Biology

Plants are known for their capacity to regenerate the whole body through de novo formation of apical meristems from a mass of proliferating cells named callus. Exogenous cytokinin and auxin determine cell fate for the establishment of the stem cell niche, which is the vital step of shoot regeneration, but the underlying mechanisms remain unclear. Here, we show that type-B ARABIDOPSIS RESPONSE REGULATORs (ARRs), critical components of cytokinin signaling, activate the transcription of WUSCHEL (WUS), which encodes a key regulator for maintaining stem cells. In parallel, type-B ARRs inhibit auxin accumulation by repressing the expression of YUCCAs, which encode a key enzyme for auxin biosynthesis, indirectly promoting WUS induction. Both pathways are essential for de novo regeneration of the shoot stem cell niche. In addition, the dual regulation of type-B ARRs on WUS transcription is required for the maintenance of the shoot apical meristem in planta. Thus, our results reveal a long-standing missing link between cytokinin signaling and WUS regulator, and the findings provide critical information for understanding cell fate specification.