1. Academic Validation
  2. TOP1α fine-tunes TOR-PLT2 to maintain root tip homeostasis in response to sugars

TOP1α fine-tunes TOR-PLT2 to maintain root tip homeostasis in response to sugars

  • Nat Plants. 2022 Jul;8(7):792-801. doi: 10.1038/s41477-022-01179-x.
Hao Zhang  # 1 2 3 4 Lin Guo  # 5 6 7 Yongpeng Li  # 3 Dan Zhao  # 1 4 8 Luping Liu 3 Wenwen Chang 3 Ke Zhang 2 Yichao Zheng 1 4 Jiajie Hou 9 Chenghao Fu 10 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 9 Shuzhi Zheng 1 4 Wenqiang Tang 1 4 Jingao Dong 11 Xigang Liu 12 13 14
Affiliations

Affiliations

  • 1 Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, China.
  • 2 State Key Laboratory of North China Crop Improvement and Regulation, Key Laboratory of Hebei Province for Plant Physiology and Molecular Pathology, Hebei Agricultural University, Baoding, China.
  • 3 State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Shijiazhuang, China.
  • 4 Hebei Collaboration Innovation Center for Cell Signaling, Shijiazhuang, China.
  • 5 Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, China. [email protected].
  • 6 State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Shijiazhuang, China. [email protected].
  • 7 Hebei Collaboration Innovation Center for Cell Signaling, Shijiazhuang, China. [email protected].
  • 8 College of Life Sciences, Hengshui University, Hengshui, China.
  • 9 Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Science, Hebei Normal University, Shijiazhuang, China.
  • 10 Food Science College, Shenyang Agricultural University, ShenYang, China.
  • 11 State Key Laboratory of North China Crop Improvement and Regulation, Key Laboratory of Hebei Province for Plant Physiology and Molecular Pathology, Hebei Agricultural University, Baoding, China. [email protected].
  • 12 Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, China. [email protected].
  • 13 State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Shijiazhuang, China. [email protected].
  • 14 Hebei Collaboration Innovation Center for Cell Signaling, Shijiazhuang, China. [email protected].
  • # Contributed equally.
Abstract

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.

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