Cytokinin content in the aerial portions and roots of wild-type (WT) and transgenic seedlings overexpressing <i>AtSOFL1</i> (OX-SOFL1) or <i>AtSOFL2</i> (OX-SOFL2).

Cytokinin quantification was performed on aerial tissue and roots of two-week-old seedlings. The results are based on three independent experiments and resulting data are expressed as means ± standard error. (*) equals P<0.5 and (**) equals P<0.05 from a Student's unpaired two-tailed t test comparing the mutant and the wild-type seedlings. The levels of trans-zeatin (tZ), cis-zeatin (cZ), N6-(Δ2-isopentenyl)adenine (iP), cis-zeatin riboside (cZR) and N6-(Δ2-isopentenyl)adenosine (iPR) were below the detection limit. §, transgenic plants expressing the empty pCHF3 vector, used as control for cytokinin measurement; tZR, trans-zeatin riboside; tZRMP, trans-zeatin riboside monophosphate; tZ7G, trans-zeatin 7-glucoside; cZRMP, cis-zeatin riboside monophosphate; cZ7G, cis-zeatin 7-glucoside; iPRMP, N6-(Δ2-isopentenyl)adenosine monophosphate; iP7G, N6-(Δ2-isopentenyl)adenine 7-glucoside.