Analysis of Arabidopsis mutants deficient in flavonoid biosynthesis

Authors

  • Brenda W. Shirley,

    Corresponding author
    1. Department of Biology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0406, USA
    2. Department of Genetics, Harvard Medical School and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
      *For correspondence (fax +1 540 231 9307).
    Search for more papers by this author
  • William L. Kubasek,

    1. Department of Genetics, Harvard Medical School and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
    Search for more papers by this author
  • Gisela Storz,

    1. Department of Genetics, Harvard Medical School and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
    2. Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
    Search for more papers by this author
  • Edward Bruggemann,

    1. Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
    Search for more papers by this author
  • Maarten Koornneef,

    1. Department of Genetics, Agricultural University, Dreijenlaan 2, 6703 HA, Wageningen, The Netherlands
    Search for more papers by this author
  • Frederick M. Ausubel,

    1. Department of Genetics, Harvard Medical School and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
    Search for more papers by this author
  • Howard M. Goodman

    1. Department of Genetics, Harvard Medical School and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
    Search for more papers by this author

*For correspondence (fax +1 540 231 9307).

Abstract

Eleven loci that play a role in the synthesis of flavonoids in Arabidopsis are described. Mutations at these loci, collectively named transparent testa (tt), disrupt the synthesis of brown pigments in the seed coat (testa). Several of these loci (tt3, tt4, tt5 and ttg) are also required for the accumulation of purple anthocyanins in leaves and stems and one locus (ttg) plays additional roles in trichome and root hair development. Specific functions were previously assigned to tt1–7 and ttg. Here, the results of additional genetic, biochemical and molecular analyses of these mutants are described. Genetic map positions were determined for tt8, tt9 and tt10. Thin-layer chromatography identified tissue- and locus-specific differences in the flavonols and anthocyanidins synthesized by mutant and wild-type plants. It was found that UV light reveals distinct differences in the floral tissues of tt3, tt4, tt5, tt6 and ttg, even though these tissues are indistinguishable under visible light. Evidence was also uncovered that tt8 and ttg specifically affect dihydroflavonol reductase gene expression. A summary of these and previously published results are incorporated into an overview of the genetics of flavonoid biosynthesis in Arabidopsis.

Ancillary