Transgenic expression of a putative calcium transporter affects the time of Arabidopsis flowering

Plant J. 2003 Jan;33(2):285-92. doi: 10.1046/j.1365-313x.2003.01627.x.

Abstract

PPF1 is a gibberellin-induced, vegetative growth-specific gene, first isolated from short-day (SD)-grown G2 pea plants. In the current work, we found that transgenic Arabidopsis plants overexpressing the PPF1 gene (PPF1 (+)) flowered much later and had a significantly longer lifespan compared to control plants, whereas suppression of this gene (PPF1 (-)) resulted in a very rapid reproductive cycle. Western blotting analyses of PPF1 (+) and (-) plant lines revealed a positive correlation between the amount of antibody-reactive protein and the time of flowering. Green fluorescent protein (GFP) co-expression assays showed that the PPF1 protein is likely localized in chloroplast membranes. Transgenic expression of PPF1 affected the calcium storage capacities since chloroplasts isolated from PPF1 (+) plants contained high Ca2+ levels while chloroplasts of PPF1 (-) plants contained very low amounts of calcium ion. Using Novikoff human hepatoma cells, we demonstrated that expression of PPF1 leads to a significant inward calcium ion current that was absent in untransformed cells. We conclude that, as a putative calcium ion carrier, PPF1 affects the flowering time of higher plants by modulating Ca2+ storage capacity within chloroplasts.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / cytology
  • Arabidopsis / genetics
  • Arabidopsis / growth & development*
  • Arabidopsis / metabolism
  • Calcium / metabolism
  • Calcium-Binding Proteins / genetics*
  • Calcium-Binding Proteins / metabolism*
  • Cell Line, Tumor
  • Chloroplasts / metabolism
  • Flowers / genetics
  • Flowers / growth & development*
  • Flowers / metabolism
  • Gene Expression
  • Humans
  • Phenotype
  • Pisum sativum / genetics
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism*
  • Plants, Genetically Modified
  • Time Factors
  • Transgenes / genetics

Substances

  • Calcium-Binding Proteins
  • PPF-1 protein, Pisum sativum
  • Plant Proteins
  • Calcium