Meristem stem cell regulation in plant inflorescence development, evolution, and maize domestication revealed by single-cell and spatial analyses

Abstract:
Stem cell regulation and meristem fate transitions are central to plant shoot development and crop yield, yet their genetic control has been difficult to resolve due to redundancy and pleiotropy. Using high-resolution single-cell and spatial gene expression profiling combined with genome editing, we dissected the regulatory networks underlying inflorescence shoot development across evolutionary scales—from monocots to eudicots, among cereals, and between maize and its wild progenitor, teosinte.

We generated a stage-resolved single-cell RNA sequencing atlas of maize developing ear inflorescences and compared it with Arabidopsis developing inflorescences, recovering thousands of stem cells marked by CLAVATA3 and WUSCHEL. Cross-species analysis uncovered conserved stem cell regulators, including the SERPINE1 mRNA-binding protein family, with validated roles in shoot development. By comparing maize stem cell overproliferation mutants with wild type at single-cell resolution, we identified two WUSCHEL-targeted sugar kinase subfamilies, one of which modulates cytokinin homeostasis to control stem cell maintenance and meristem size.

In cereal crops, we generated single-cell and spatial atlases of spike inflorescence development in wheat and compared them to maize, revealing conserved transcriptional regulators shaping inflorescence architecture. By comparing maize to its ancestor teosinte, we identified genetic shifts in meristem identity and inflorescence complexity during domestication. Overall, our work establishes a single-cell framework for dissecting inflorescence evolution and guiding strategies for crop improvement.

About the Speaker:
Xiaosa (Jack) Xu is a new Assistant Professor in the Plant Biology Department at UC Davis. He attended the University of Texas at Austin for his Ph.D., where he worked with Prof. Enamul Huq to investigate how light regulates photomorphogenesis in Arabidopsis. With a passion for incorporating developmental research into crop improvement, Xu then moved to Cold Spring Harbor Laboratory (CSHL) for postdoctoral research with Prof. David Jackson. There, he used developmental genetics and cutting-edge single-cell genomics to understand maize inflorescence architecture and inform crop yield trait associations. As an independent investigator at UC Davis, he integrates single-cell genomics, spatial transcriptomics, and genome editing to investigate plant development, cereal crop inflorescence evolution, and maize domestication, with the goal of advancing crop improvement.

Contact

  Surinder Chopra
  sic3@psu.edu