Table I.

Labeling of amino acids by ³H supplied as Glu in apical and basal sections of the root tip at high (−0.02 MPa) or low (−1.6 MPa) ψ_w.

Amino Acid	High ψw				Low ψw
	Apical		Basal		Apical		Basal
	dpm RS−1	dpm nmol−1	dpm RS−1	dpm nmol−1	dpm RS−1	dpm nmol−1	dpm RS−1	dpm nmol−1
Asp	47	16	33	32	118	30	90	46
Asn	19	12	13	3	23	4	22	2
Ser	8	7	13	6	25	10	17	5
Gln	174	12	87	4	1830	70	847	48
Arg	27	57	30	116	162	274	104	398
GABA	72	118	53	113	250	58	44	108
Thr	16	17	24	10	56	29	30	10
Ala	8	2	9	1	29	4	9	1

Apical and basal sections were harvested after 120 min of labeling, as shown in Figure 1. Data are means of two samples from two experiments. RS, Root section.