Figure 1.

Ion transporter genes regulated by photosynthesis. The plants were pretreated for 40 h in darkness to repress light- or sugar-inducible transporter genes. Two experiments were performed. In the first one (left panel for each gene), the plants were transferred for 4 h in the light or left in the dark in an atmosphere containing 0, 300, or 600 μL L⁻¹ CO₂. In the second experiment (right panel for each gene), the plants were either kept for 4 additional h in the dark without Suc supply (D), kept in the dark and supplied with 1% Suc for 4 h (D+S), or transferred in the light and supplied with 1% Suc for 4 h (L+S). All transcripts were measured in the roots using real-time quantitative PCR and normalized to a putative clathrin coat-assembly protein gene (At4g24550). The data represent the mean and sd of at least three independent experiments (two replicates from each experiment).