Abstract
SULTR1;1 and SULTR1;2 are two high-affinity sulfate transporters co-localizing at epidermis and cortex of Arabidopsis roots for the uptake of sulfate from the environment during sulfur limitation (-S). Previously, we have reported that -S induction of SULTR1;1 and SULTR1;2 transcripts are dependent on their promoters activities. To analyze post-transcriptional regulation of SULTR1;1 and SULTR1;2, we generated transgenic plants that rescue the sulfate uptake capacity of sultr1;1 sultr1;2 double knockout mutant by constitutively over-expressing SULTR1;1 or SULTR1;2 under the control of 35S RNA promoter. In transgenic plants, SULTR1;1 mRNA was expressed only in roots, and SULTR1;1 protein content was increased by -S. By contrast, SULTR1;2 mRNA was expressed in both roots and leaves, however SULTR1;2 protein was accumulated exclusively in roots during -S. The present study suggested existence of post-transcriptional mechanisms for the control of SULTR1;1 and SULTR1;2, playing important roles in optimizing the uptake of sulfate during -S.