Figure 1
Luciferase (LUC) activity at two temperatures in candidate promoter tagged line ET2-17 of 'Three Hand Planty' throughout in vitro regeneration. (A) Representative images were taken under normal light (Live) and dark (LUC) conditions of candidate tagged line 17 transformed with pETKUL2 (promoterless luc+ gene), a positive control line carrying the luc+ gene under control of the enhanced CaMV 35S RNA promoter (+), and a negative untransformed control line (-). Developmental stages I, II, and III correspond to cell colony, differentiation and plantlet stage, respectively. The last LUC image recorded at 26°C and the LUC image recorded after 2 h at 8°C are depicted in pseudocolors (see color bar) with an upper greyscale limit setting of 1000. Arrows indicate the corresponding cell colony. Scale bars represent 1 cm. (B) Time course of LUC activity during temperature shift in promoter tagged line ET2-17 (17) and a positive (CaMV35S) transgenic control line (+) of banana throughout the in vitro regeneration process. LUC activity was monitored for 2 h at 26°C, then at time point zero (indicated by an arrow) temperature was set to 8°C, which was reached 1 h later, and then maintained for 2 h (stages I and II) or 4 h (stage III) (solid line above the graphs). The region of interest for quantification of LUC activity was standardized to 0.34, 0.58, and 23.19 cm2 for stages I, II, and III, respectively. The Y axis scale are different for line 17 and the control line in stages II and III and indicated on either side of the graph