Figure 1.

Representative ³¹P-NMR spectra of carrot cells incubated with 1.5 mm GroPCho at pH 6; 10 g (fresh weight) of carrot cells was perfused with 200 mL of a nutrient medium containing GroPCho as the sole source of phosphate. After 5 h of incubation, medium and cells were collected and analyzed separately (B and C). Glc-6-P, Glc-6-phosphate; cyt-Pi, cytoplasmic Pi; vac-Pi, vacuolar Pi; NTP, nucleotide triphosphate (mainly ATP and UTP). A, In vivo ³¹P-NMR spectra of carrot cells at the beginning of the incubation (A₁, t = 0) and after 3 h of incubation (A₂). B, ³¹P-NMR spectra (expanded scale from −1 to 6 ppm) of the medium collected after the incubation. C, ³¹P-NMR spectra (expanded scale from −1 to 6 ppm) of the perchloric extract from carrot cells collected after the incubation.