Gibberellins and light-stimulated seed germination

Shinjiro Yamaguchi, Yuji Kamiya

    Research output: Contribution to journalArticlepeer-review

    83 Citations (Scopus)

    Abstract

    Bioactive gibberellins (GAs) promote seed germination in a number of plant species. In dicots, such as tomato and Arabidopsis, de novo GA biosynthesis after seed imbibition is essential for germination. Light is a crucial environmental cue determining seed germination in some species. The red (R) and far-red light photoreceptor phytochrome regulates GA biosynthesis in germinating lettuce and Arabidopsis seeds. This effect of light is, at least in part, targeted to mRNA abundance of GA 3-oxidase, which catalyzes the final biosynthetic step to produce bioactive GAs. The R-inducible GA 3-oxidase genes are predominantly expressed in the hypocotyt of Arabidopsis embryos. This predicted location of GA biosynthesis appears to correlate with the photosensitive site determined by using R micro-beam in lettuce seeds. The GA-deficient non-germinating mutants have been useful for studying how GA stimulates seed germination. In tomato, GA promotes the growth potential of the embryo and weakens the structures surrounding the embryo. Endo-β-mannanase, which is produced specifically in the micropylar endosperm in a GA-dependent manner, may be responsible for breaking down the endosperm cell walls to assist germination. Recently, a role for GA in overcoming the resistance imposed by the seed coat was also suggested in Arabidopsis from work with a range of seed coat mutants. Towards understanding the GA signaling pathway, GA response mutants have been isolated and characterized, some of which are affected in GA-stimulated seed germination.

    Original languageEnglish
    Pages (from-to)369-376
    Number of pages8
    JournalJournal of Plant Growth Regulation
    Volume20
    Issue number4
    DOIs
    Publication statusPublished - 2001 Dec 1

    Keywords

    • Biosynthesis
    • Cellular localization
    • Germination
    • Gibberellin
    • Phytochrome
    • Seed coat

    ASJC Scopus subject areas

    • Agronomy and Crop Science
    • Plant Science

    Fingerprint Dive into the research topics of 'Gibberellins and light-stimulated seed germination'. Together they form a unique fingerprint.

    Cite this