Table I. Effect of PTN1 and PTN4 on Pi absorption is similar in a wide range of Pi concentration.

Plants were grown for 5 d in complete medium (full) then transferred for 5 d in low Pi with or without (Control) drugs (at optimal concentration). Pi influx was measured during 2 h in ³³P supplemented with 5, 25, 50, 100, 500, and 1,000 μm Pi for the measure of V_max and K_m. At least 10 plants were used for each point.

Transporter	Control		PTN1		PTN4
	Vmax	Km	Vmax	Km	Vmax	Km
High affinity	0.14	9.4	0.12	13.3	0.09	8.2
Low affinity	0.37	104.3	0.27	91.6	0.3	108.6