Fig. 5.

Quantitative RT-PCR analyses of riboflavin synthesis genes in cucumber (cv. Ashley) roots (A–E) and first leaf (F–J) after 3 days of treatment. The results were normalized to ubiquitin as an internal reference. The transcript abundance of each gene (means±SE, n=3) was normalized to transcript abundance in roots of the control treatment (10 μM Fe and 0mM bicarbonate). * and ** indicate statistical significance at P<0.05 and P<0.01, respectively, comparing bicarbonate treatments within the same Fe supply; Ŧ and ŦŦ indicate statistical significance at P<0.05 and P<0.01, respectively, comparing different Fe supply within the same bicarbonate treatment.