Table II.

Concentrations of amino acids (in micromolar) in sugar beet apoplastic fluid from iron-deficient (−ironI, 50 μmol Chl m⁻²) and iron-sufficient (⁺iron, 300 μmol Chl m⁻²) leaves

Amino Acid	Iron-Sufficient	Iron-Deficient
	(+Iron)	(−Iron)	−Iron/+Iron
Asp	262 ± 20	177 ± 28	0.7
Ser	121 ± 42	182 ± 56	1.5
Glu	320 ± 3	538 ± 83	1.7
Gln	450 ± 180	396 ± 90	0.9
Pro	<1	77 ± 43	–
Ala	303 ± 130	243 ± 52	0.8
Val	60 ± 55	510 ± 50	8.5
GABA	56 ± 11	166 ± 12	3.0
Thr	44 ± 15	39 ± 8	0.9
Asn	59 ± 10	33 ± 3	0.5
Gly	56 ± 8	48 ± 12	0.8
Ile	16 ± 16	9 ± 4	0.6
Leu	<1	14 ± 7	–
Lys	31 ± 0.5	12 ± 0.1	0.4
His	<1	4 ± 2	–
Total amino acids	1,778	2,448	1.4

Data are means ± se of five replications.