Table I.

Amounts of Phe taken up by the wild type, lht1-1, gdu1-1D, and the corresponding double mutant and subsequently released in the medium

After incubation with Phe supplied at the indicated concentration for 10 min, plantlets were quickly rinsed and placed in fresh medium for 1 h. Total Phe taken up was estimated by adding the amounts of radioactivity in the medium (efflux) and left in the plants after efflux analyses. Means ± se of three biological replicates are shown. Significant differences from the wild type are as follows (t test): ** P < 0.02, * P < 0.05.

Plant	1 mm			10 μm
	Totala	Effluxa	Percentageb	Totala	Effluxa	Percentageb
Wild type	456 ± 45	64 ± 6	14 ± 2	20.8 ± 3.9	1.9 ± 0.3	9 ± 1
gdu1-1D	255 ± 15*	150 ± 16*	59 ± 3**	3.2 ± 0.1*	1.8 ± 0.1	55 ± 5**
lht1-1	354 ± 22	62 ± 5	18 ± 0	5.6 ± 0.6*	0.6 ± 0.1*	12 ± 1
gdu1-1D/lht1-1	239 ± 28*	135 ± 17**	56 ± 1**	2.7 ± 0.2*	1.3 ± 0	50 ± 4**

^anmol mg⁻¹ chlorophyll.

^bPercentage of Phe present in the medium relative to total Phe taken up.