Abstract
Sulfate transporter gene family of Arabidopsis is consisted of 14 isoforms classified into 5 groups. In this study, we demonstrated that Sultr3;5 is able to complement the sulfate uptake capacity of the yeast mutant lacking sulfate transporters. Transgenic Arabidopsis expressing the fusion gene construct of Sultr3;5 promoter and GFP showed the specific expression in the root pericycle and xylem parenchyma cells. The low-affinity sulfate transporter, Sultr2;1 is localized in the same tissue, therefore, we conducted functional analysis of both transporters using their knockout or antisensed plants. Measurement of translocation of 35[S] sulfate from root to shoot revealed that movement of sulfate to shoot was accelerated in the Sultr2;1 antisense and Sultr3;5 knockout plants compared to their wild type. These results suggest that both Sultr2;1 and Sultr3;5 facilitate transport of sulfate into the pericycle and xylem parenchyma cells from apoplasic space in the stele, restricting translocation of sulfate to the shoot.
