Transactivation of the 2CPA promoter by Rap2.4a. (A) Activation of the 2CPA promoter by Rap2.4a. Arabidopsis mesophyll protoplasts were co-transfected with plasmids encoding Rap2.4a and CFP under control of the CaMV35S-promoter and a reference plasmid encoding YFP under control of the 2CPA promoter. YFP and CFP fluorescence were quantified from 40 cells each by confocal laser scanning microscopy (CLSM) and compared to protoplasts co-transfected with a control CaMV35S plasmid and the reporter and reference constructs. (B) In vivo analysis of the function of C
in 2CPA promoter activation by Rap2.4a. Arabidopsis mesophyll protoplasts were co-transfected with reporter gene constructs expressing YFP either under control of the wild-type 2CPA promoter or a mutagenized 2CPA promoter, in which C3G4 was replaced by TT. The YFP fluorescence was quantified from 40 cells by CLSM and standardized on CFP activity expressed under control of the CaMV35S promoter. The averages were significantly different according to Student's t-Test (a ≤ 10%).