SLC26A2 and hyperinsulinemic hypoglycemia, familial, 4: Typical S-deficiency-responses in Arabidopsis are the activation of sulfate uptake by up-regulating the expressions of high-affinity sulfate transporter genes AtSULTR1;1 and AtSULTR1;2 in the roots and the enhancement of sulfate assimilation in the shoots by activating the expressions of AtATPS1, AtATPS3, and AtATPS4 [12,13,14].