Nature Plants ( IF 18.0 ) Pub Date : 2022-07-11 , DOI: 10.1038/s41477-022-01179-x Hao Zhang 1, 2, 3, 4 , Lin Guo 1, 3, 4 , Yongpeng Li 3 , Dan Zhao 1, 4, 5 , Luping Liu 3 , Wenwen Chang 3 , Ke Zhang 2 , Yichao Zheng 1, 4 , Jiajie Hou 6 , Chenghao Fu 7 , Ying Zhang 2 , Baowen Zhang 1, 4 , Yuru Ma 1, 4 , Yanxiao Niu 1, 4 , Kang Zhang 2 , Jihong Xing 2 , Sujuan Cui 1, 4 , Fengru Wang 2 , Ke Tan 6 , Shuzhi Zheng 1, 4 , Wenqiang Tang 1, 4 , Jingao Dong 2 , Xigang Liu 1, 3, 4
Plant development is highly dependent on energy levels. TARGET OF RAPAMYCIN (TOR) activates the proximal root meristem to promote root development in response to photosynthesis-derived sugars during photomorphogenesis in Arabidopsis thaliana. However, the mechanisms of how root tip homeostasis is maintained to ensure proper root cap structure and gravitropism are unknown. PLETHORA (PLT) transcription factors are pivotal for the root apical meristem (RAM) identity by forming gradients, but how PLT gradients are established and maintained, and their roles in COL development are not well known. We demonstrate that endogenous sucrose induces TOPOISOMERASE1α (TOP1α) expression during the skotomorphogenesis-to-photomorphogenesis transition. TOP1α fine-tunes TOR expression in the root tip columella. TOR maintains columella stem cell identity correlating with reduced quiescent centre cell division in a WUSCHEL RELATED HOMEOBOX5-independent manner. Meanwhile, TOR promotes PLT2 expression and phosphorylates and stabilizes PLT2 to maintain its gradient consistent with TOR expression pattern. PLT2 controls cell division and amyloplast formation to regulate columella development and gravitropism. This elaborate mechanism helps maintain root tip homeostasis and gravitropism in response to energy changes during root development.
中文翻译:
TOP1α 微调 TOR-PLT2 以维持根尖动态平衡以响应糖分
植物发育高度依赖于能量水平。雷帕霉素 (TOR) 的目标激活近端根分生组织以促进根系发育,以响应拟南芥光形态发生过程中光合作用衍生的糖分。然而,如何维持根尖稳态以确保适当的根冠结构和向重力性的机制尚不清楚。PLETHORA (PLT) 转录因子通过形成梯度对根尖分生组织 (RAM) 的识别至关重要,但 PLT 梯度的建立和维持方式及其在 COL 发育中的作用尚不清楚。我们证明内源性蔗糖在暗形态发生到光形态发生转变期间诱导TOPOISOMERASE1α ( TOP1α ) 表达。TOP1α微调TOR在根尖小柱中的表达。TOR 以WUSCHEL RELATED HOMEOBOX5独立方式维持与减少的静止中心细胞分裂相关的小柱干细胞特性。同时,TOR 促进PLT2表达并磷酸化和稳定 PLT2 以保持其与TOR表达模式一致的梯度。PLT2 控制细胞分裂和造粉体形成以调节小柱发育和向重力性。这种精心设计的机制有助于维持根尖稳态和向重力性,以响应根系发育过程中的能量变化。