Crop Journal (Feb 2024)

ZmCYP90D1 regulates maize internode development by modulating brassinosteroid-mediated cell division and growth

  • Canran Sun,
  • Yang Liu,
  • Guofang Li,
  • Yanle Chen,
  • Mengyuan Li,
  • Ruihua Yang,
  • Yongtian Qin,
  • Yongqiang Chen,
  • Jinpeng Cheng,
  • Jihua Tang,
  • Zhiyuan Fu

Journal volume & issue
Vol. 12, no. 1
pp. 58 – 67

Abstract

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Plant height (PH) is associated with lodging resistance and planting density, which is regulated by a complicated gene network. In this study, we identified a spontaneous dwarfing mutation in maize, m30, with decreased internode number and length but increased internode diameter. A candidate gene, ZmCYP90D1, which encodes a member of the cytochrome P450 family, was isolated by map-based cloning. ZmCYP90D1 was constitutively expressed and showed highest expression in basal internodes, and its protein was targeted to the nucleus. A G-to-A substitution was identified to be the causal mutation, which resulted in a truncated protein in m30. Loss of function of ZmCYP90D1 changed expression of hormone-responsive genes, in particular brassinosteroid (BR)-responsive genes which is mainly involved in cell cycle regulation and cell wall extension and modification in plants. The concentration of typhasterol (TY), a downstream intermediate of ZmCYP90D1 in the BR pathway, was reduced. A haplotype conferring dwarfing without reducing yield was identified. ZmCYP90D1 was inferred to influence plant height and stalk diameter via hormone-mediated cell division and cell growth via the BR pathway.

Keywords