Table 7.
Concentration and Proportion of Amino Acids in the Xylem Sap of the Wild Type and Cytosolic GS-Deficient Mutants
| Amino Acid Concentration (μmol μL−1) and Proportions (%)a
|
||||
|---|---|---|---|---|
| Amino Acid | Wild Type | gln1-4 | gln1-3 | gln1-3 gln1-4 |
| Asp | 13.8 ± 7.8 (7.8) | NAb | 19.8 ± 2.8 (17.1) | 13.6 ± 7.0 (9.1) |
| Asn | 57.0 ± 18.5 (32.1) | 18.0 ± 4.2 (15.5)c | 38 ± 13.6 (25.5)c | |
| Glu | 5.6 ± 2.5 (3.1) | 2.2 ± 0.4 (1.8)c | 4.6 ± 1.8 (3.0)c | |
| Gln | 42.4 ± 8.5 (23.9) | 32.6 ± 3.2 (28.1)c | 35.6 ± 1.6 (23.8)c | |
| Ala | 8.2 ± 1.4 (4.6) | 1.0 ± 2 (0.8) | 9.2 ± 2.8 (6.1) | |
| GABA | 1.0 ± 0.6 (0.5) | 0.2 ± 0.4 (0.2) | 1.4 ± 1.0 (0.9) | |
| Pro | 0 ± 0 (0) | 0 ± 0 (0) | 0 ± 0 (0) | |
| Others | 49.4 ± 11.4 (28) | 42.4 ± 4.4 (36.5) | 46.6 ± 5.8 (31.6) | |
| Total | 177.4 ± 8.9 (100) | 116.2 ± 2.0 (100) | 149.0 ± 7.3 (100) | |
a
Amino acids were separated and quantified in the xylem sap of detopted maize plants at VS. The plants were grown hydroponically on the medium described by Coïc and Lesaint (1971). Values are the mean of three plants ± sd. Relative amino acid proportions are given in parentheses.
b
Not available.
c
No significant changes in the amino acid content compared with the WT at the 0.05 probability level.