Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Identification of Endogenous Gibberellins in Petunia Flowers: Induction of Anthocyanin Biosynthetic Gene Expression and the Antagonistic Effect of Abscisic Acid

David Weiss, Arnold van der Luit, Erik Knegt, Evert Vermeer, Joseph N. M. Mol and Jan M. Kooter
Plant Physiology
Vol. 107, No. 3 (Mar., 1995), pp. 695-702
Stable URL: http://www.jstor.org/stable/4276381
Page Count: 8
  • Read Online (Free)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Identification of Endogenous Gibberellins in Petunia Flowers: Induction of Anthocyanin Biosynthetic Gene Expression and the Antagonistic Effect of Abscisic Acid
Preview not available

Abstract

The elongation and pigmentation of corollas of Petunia hybrida requires the presence of anthers. The ability of exogenous gibberellic acid (GA3) to substitute for the anthers suggests a role for endogenous GAs. Here we report the identification of endogenous GAs in corollas and in anthers and show that both tissues contain detectable levels of $\text{GA}_{1}$, GA4, and GA9, of which GA4 is the most abundant. These GAs stimulate corolla pigmentation, chalcone synthase (chs) mRNA accumulation, and chs transcription in an in vitro flower bud culture system. Methyl ester derivatives of GA3 and GA4 were not active but did not inhibit the bioactive GAs. Even though it is unknown whether abscisic acid (ABA) is involved in corolla maturation, ABA inhibited pigmentation of intact flowers, overruling the effect of the anthers. In detached flower buds it was shown that ABA prevented activation of the chs promoter by GA3. The synthesis of anthocyanin pigments requires the coordinate expression of at least 15 structural genes. Expression of early biosynthetic genes and of late biosynthetic genes are regulated by different transcriptional activators. GA induces both classes of genes with similar kinetics, indicating that GA acts relatively early in the signaling pathway.

Page Thumbnails

  • Thumbnail: Page 
695
    695
  • Thumbnail: Page 
696
    696
  • Thumbnail: Page 
697
    697
  • Thumbnail: Page 
698
    698
  • Thumbnail: Page 
699
    699
  • Thumbnail: Page 
700
    700
  • Thumbnail: Page 
701
    701
  • Thumbnail: Page 
702
    702