Table 3.

Concentrations of Free His in Shoot and Root Tissues of 35S:PRT2 Lines 21.2 and 30.5 Relative to Controls

	His Concentration (mmol kg−1 Dry Biomass)
Line	Shoot	Root
21.2	20.8 ± 3.23***	3.44 ± 0.09*
30.5	18.1 ± 1.14***	3.21 ± 0.22*
pBI121	2.50 ± 0.40	1.51 ± 0.18
Wild type	1.38 ± 0.21	1.46 ± 0.12

Values are means ± se (n = 4 independent replicates); each replicate consisted of tissue pooled from four 5-week-old plants cultivated hydroponically without added Ni. Values significantly different from those of wild-type plants are indicated with three asterisks for P < 0.001 and with one asterisk for P < 0.05.