NRP-A and NRP-B induces GmNAC6 promoter activation. A. The transient expression of NIG, NRP-A and NRP-B in soybean protoplasts from suspension cells. Plasmids carrying 35S::NIG, 35S::NRP-A or 35S::NRP-B expression cassettes or empty vector were electroporated into soybean protoplasts, and the efficiency of transfection was monitored by determining the transient expression (qRT-PCR) 36 h after electroporation. B. The transient expression of NRP-A and NRP-B in soybean protoplasts activates a GmNAC6 promoter::β-glucuronidase gene. Soybean protoplasts were co-electroporated with plasmids carrying a GmNAC6-promoter::β-glucuronidase gene and either 35S::NIG, 35S::NRP-A or 35S::NRP-B DNA constructs, or the empty vector (pNAC6). After 36 h, the β-glucuronidase activity (nmol/min/mg protein) was measured in the total protein extracts of transfected soybean cells. The values represent the mean ± SD of five replicates from three independent experiments. Asterisks indicate mean values statistically different from the control treatment.