Transient induction of melatonin biosynthesis in rice (Oryza sativa L.) during the reproductive stage

Authors

  • Sangkyu Park,

    1. Interdisciplinary Program of Bioenergy and Biomaterials, Department of Biotechnology, Bioenergy Research Center, Chonnam National University, Gwangju, South Korea
    Search for more papers by this author
    • These authors equally contributed to this article.
  • Tieu-Ngoc Nguyen Le,

    1. Agriculture and Forestry Faculty, Tay Nguyen University, Vietnam
    Search for more papers by this author
    • These authors equally contributed to this article.
  • Yeong Byeon,

    1. Interdisciplinary Program of Bioenergy and Biomaterials, Department of Biotechnology, Bioenergy Research Center, Chonnam National University, Gwangju, South Korea
    Search for more papers by this author
  • Young Soon Kim,

    1. Interdisciplinary Program of Bioenergy and Biomaterials, Department of Biotechnology, Bioenergy Research Center, Chonnam National University, Gwangju, South Korea
    Search for more papers by this author
  • Kyoungwhan Back

    Corresponding author
    • Interdisciplinary Program of Bioenergy and Biomaterials, Department of Biotechnology, Bioenergy Research Center, Chonnam National University, Gwangju, South Korea
    Search for more papers by this author

Address reprint requests to Kyoungwhan Back

Department of Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, South Korea.

E-mail: kback@chonnam.ac.kr

Abstract

The regulation of reproduction-stage inducible melatonin biosynthesis in rice (Oryza sativa cv. Dongjin) was investigated. The flag leaf and panicle (flower) were collected from field-grown rice at three different reproductive stages: the preflowering stage, flowering stage, and postflowering stage. Melatonin synthesis was induced in the panicle, whereas no induction was observed in the flag leaf during the reproductive stages. The panicle displayed a peak melatonin level of 0.4 ng/g fresh weight (fw), which was six times that found in the flag leaf. The induction of melatonin biosynthesis was paralleled by the induction of corresponding genes and proteins such as tryptophan decarboxylase, tryptamine 5-hydroxylase, and N-acetylserotonin methyltransferase. In addition, melatonin induction was preceded by the accumulation of its precursor, tryptophan, in the panicle. These results suggest that the induction of melatonin during flower development is regulated by the transcriptional control of its biosynthesis genes and that melatonin may participate in flower development.

Ancillary