2.8 Electrophoretic mobility shift assay (EMSA)
Biotin-labeled, unlabeled, and mutant probes of promoters ofMdNRT2.1 and MdNRT2. 4 (Sangon Biotech, China) and
MdHY5-His protein were prepared. The corresponding probes were incubated
with MdHY5-His protein or without protein in binding buffer (5 mM
MgCl2, 2.5% glycerol, 10 mM EDTA, and 50 mM KCl) for
20 min at 23 °C. EMSA was then conducted with an EMSA kit (Thermo
Scientific, Waltham, MA, USA) following the manufacturer’s instructions.