Figure 4.

Sucrose transport activity of SlSWEET15 in yeast. A, Growth assay of YSL2-1 cells expressing SlSWEET15. Yeast cells expressing SlSWEET15, ScHXT5, AtSUC2, or an empty vector (vector) were serially diluted (10-fold) and cultured on solid media supplemented with maltose or 2%–5% w/v sucrose, respectively. Images were captured after incubation at 30°C for 4 d. B, Growth curve of yeast cells in (A). Fresh cells were diluted in liquid media supplement with 5% w/v sucrose. OD₆₀₀ of cell cultures were measured every 4 h. Results are mean ± se from four independent colonies from four independent experiments. Differences from cells containing an empty vector (Student’s t test): *P < 0.05, **P < 0.01. C, Vacuolar localization of SlSWEET15–GFP fusions in YSL2-1 yeast cells observed by confocal microscopy. Scale = 5 mm. Representative pictures in (A) and (C) were derived from three independent experiments, containing two independent colonies.