J Integr Plant Biol. ›› 2019, Vol. 61 ›› Issue (2): 168-181.DOI: 10.1111/jipb.12696

• Molecular Physiology • Previous Articles     Next Articles

The central circadian clock proteins CCA1 and LHY regulate iron homeostasis in Arabidopsis

Gang Xu1,2†, Zhimin Jiang1,2‡, Haiyang Wang3 and Rongcheng Lin1,2,4*   

  1. 1Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
    2University of Chinese Academy of Sciences, Beijing 100049, China
    3College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
    4CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Beijing 100093, China

    Current address: College of Life Sciences, Shandong Agricultural University, Taian 271018, China
    Current address: Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China

    Email: Rongcheng Lin(rclin@ibcas.ac.cn)
  • Received:2018-05-04 Accepted:2018-07-06 Online:2018-07-10 Published:2019-02-01

Abstract: Circadian clock is the endogenous time-keeping machinery that synchronizes an organism's metabolism, behavior, and physiology to the daily light-dark circles, thereby contributing to organismal fitness. Iron (Fe) is an essential micronutrient for all organisms and it plays important roles in diverse processes of plant growth and development. Here, we show that, in Arabidopsis thaliana, loss of the central clock genes, CIRCADIAN CLOCK ASSOCIATED 1 (CCA1) and LATE ELONGATED HYPOCOTYL (LHY), results in both reduced Fe uptake and photosynthetic efficiency, whereas CCA1 overexpression confers the opposite effects. We show that root Fe(III) reduction activity, and expression of FERRIC REDUCTION OXIDASE 2 (FRO2) and IRON-REGULATED TRANSPORTER 1 (IRT1) exhibit circadian oscillations, which are disrupted in the cca1 lhy double mutant. Furthermore, CCA1 directly binds to the specific regulatory regions of multiple Fe homeostasis genes and activates their expression. Thus, this study established that, in plants, CCA1 and LHY function as master regulators that maintain cyclic Fe homeostasis.

Editorial Office, Journal of Integrative Plant Biology, Institute of Botany, CAS
No. 20 Nanxincun, Xiangshan, Beijing 100093, China
Tel: +86 10 6283 6133 Fax: +86 10 8259 2636 E-mail: jipb@ibcas.ac.cn
Copyright © 2022 by the Institute of Botany, the Chinese Academy of Sciences
Online ISSN: 1744-7909 Print ISSN: 1672-9072 CN: 11-5067/Q