Figure 10. Transactivation of the synthetic GCC-box and mGCC containing promoters by HbERF-VIIa7, HbERF-VIIa17 and HbERF-VIIa20 proteins.

Transient expression in BY-2 tobacco protoplasts co-transformed by pMDC32 harbouring the effector construct (ERF candidate genes under the control of the CaMV 35S promoter) and the reporter constructs, 4× GCC::GFP or 4× mGCC::GFP, respectively. Fluorescence activity was measured by flow cytometry for three independent biological replicates. The ratio of fluorescence between the constructs with functional GCC and mutated mGCC boxes revealed that ERF candidates are activators (ratio >1) or repressors (ratio <1). (*) indicates significant difference for the Student test (p<0.01).