Overexpression of AtCPS and AtKS in Arabidopsis confers increased ent-kaurene production but no increase in bioactive gibberellins

Christine M. Fleet, Shinjiro Yamaguchi, Atsushi Hanada, Hiroshi Kawaide, Charles J. David, Yuji Kamiya, Tai Ping Sun

    Research output: Contribution to journalArticle

    85 Citations (Scopus)

    Abstract

    The plant growth hormone gibberellin (GA) is important for many aspects of plant growth and development. Although most genes encoding enzymes at each step of the GA biosynthetic pathway have been cloned, their regulation is less well understood. To assess how up-regulation of early steps affects the biosynthetic pathway overall, we have examined transgenic Arabidopsis plants that overexpress either AtCPS or AtKS or both. These genes encode the enzymes ent-copalyl diphosphate synthase (CPS) and ent-kaurene synthase, which catalyze the first two committed steps in GA biosynthesis. We find that both CPS and CPS/ent-kaurene synthase overexpressors have greatly increased levels of the early intermediates ent-kaurene and ent-kaurenoic acid, but a lesser increase of later metabolites. These overexpression lines do not exhibit any GA overdose morphology and have wild-type levels of bioactive GAs. Our data show that CPS is limiting for ent-kaurene production and suggest that conversion of ent-kaurenoic acid to GA12 by ent-kaurenoic acid oxidase may be an important rate-limiting step for production of bioactive GA. These results demonstrate the ability of plants to maintain GA homeostasis despite large changes in accumulation of early intermediates in the biosynthetic pathway.

    Original languageEnglish
    Pages (from-to)830-839
    Number of pages10
    JournalPlant physiology
    Volume132
    Issue number2
    DOIs
    Publication statusPublished - 2003 Jun 1

    ASJC Scopus subject areas

    • Physiology
    • Genetics
    • Plant Science

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  • Cite this

    Fleet, C. M., Yamaguchi, S., Hanada, A., Kawaide, H., David, C. J., Kamiya, Y., & Sun, T. P. (2003). Overexpression of AtCPS and AtKS in Arabidopsis confers increased ent-kaurene production but no increase in bioactive gibberellins. Plant physiology, 132(2), 830-839. https://doi.org/10.1104/pp.103.021725