The maize PLASTID TERMINAL OXIDASE (PTOX) locus controls the carotenoid content of kernels

Yongxin Nie, Hui Wang, Guan Zhang, Haiping Ding, Beibei Han, Lei Liu, Jian Shi, Jiyuan Du, Xiaohu Li, Xinzheng Li, Yajie Zhao, Xiaocong Zhang, Changlin Liu, Jianfeng Weng, Xinhai Li, Xiansheng Zhang, Xiangyu Zhao, Guangtang Pan, David Jackson, Qin Bao LiPhilip S. Stinard, Jennifer Arp, Martin M. Sachs, Steven Moose, Charles T. Hunter, Qingyu Wu, Zhiming Zhang

Research output: Contribution to journalArticlepeer-review

Abstract

Carotenoids perform a broad range of important functions in humans; therefore, carotenoid biofortification of maize (Zea mays L.), one of the most highly produced cereal crops worldwide, would have a global impact on human health. PLASTID TERMINAL OXIDASE (PTOX) genes play an important role in carotenoid metabolism; however, the possible function of PTOX in carotenoid biosynthesis in maize has not yet been explored. In this study, we characterized the maize PTOX locus by forward- and reverse-genetic analyses. While most higher plant species possess a single copy of the PTOX gene, maize carries two tandemly duplicated copies. Characterization of mutants revealed that disruption of either copy resulted in a carotenoid-deficient phenotype. We identified mutations in the PTOX genes as being causal of the classic maize mutant, albescent1. Remarkably, overexpression of ZmPTOX1 significantly improved the content of carotenoids, especially β-carotene (provitamin A), which was increased by ~threefold, in maize kernels. Overall, our study shows that maize PTOX locus plays an important role in carotenoid biosynthesis in maize kernels and suggests that fine-tuning the expression of this gene could improve the nutritional value of cereal grains.

Original languageEnglish (US)
Pages (from-to)457-468
Number of pages12
JournalPlant Journal
Volume118
Issue number2
Early online dateJan 10 2024
DOIs
StatePublished - Apr 2024

Keywords

  • albescent1
  • biofortification
  • carotene
  • provitamin A

ASJC Scopus subject areas

  • Genetics
  • Plant Science
  • Cell Biology

Fingerprint

Dive into the research topics of 'The maize PLASTID TERMINAL OXIDASE (PTOX) locus controls the carotenoid content of kernels'. Together they form a unique fingerprint.

Cite this