Abstract
SULTR1;2 high-affinity sulfate transporter facilitates sulfate uptake from the environment. Arabidopsis plants induce SULTR1;2 expression upon sulfur deficiency (-S), which enables the plants to survive under -S condition. To identify the cis-acting element involved in the -S-inducible expression of SULTR1;2, its promoter region was dissected by deletion and base substitution analysis in transgenic Arabidopsis using luciferase as a reporter. The results indicated that -S-responsive expression of SULTR1;2 requires the regions from -371 to -360 and -328 to -323. The -371/-360 region contained a WRKY binding sequence (TGAC), and the -328/-323 region contained a SEF4 motif (AAAAAT), respectively. SEF4 motif is originally reported as a sulfur-responsive element in the promoter sequence of β-subunit gene of β-conglycinin from soybean, suggesting the existence of a common regulatory mechanism inducing -S response between Arabidopsis and soybean.
