Table 1.
Contents of GAs in equivalent stem segments of tall vs. semidwarf rice plants
| Compound | Content (pg
segment−1)*
|
|||||
|---|---|---|---|---|---|---|
| Kyeema (tall) | Doongara (dwarf) | P† | Calrose (tall) | Calrose 76 (dwarf) | P† | |
| 13-OH GAs‡ | ||||||
| GA53 | 802 ± 54 | 2546 ± 133 | <0.001 | 1117 ± 72 | 2033 ± 146 | 0.005 |
| GA44 | 687 ± 34 | 661 ± 42 | 0.65 (ns) | 828 ± 109 | 445 ± 61 | 0.04 |
| GA19 | 4092 ± 269 | 4108 ± 401 | 0.97 (ns) | 4233 ± 141 | 2827 ± 171 | 0.003 |
| GA20 | 178 ± 13 | 73 ± 4 | <0.001 | 270 ± 27 | 131 ± 18 | 0.012 |
| GA1 | 146 ± 8 | 96 ± 6 | 0.005 | 169 ± 15 | 134 ± 13 | 0.15 (ns) |
| GA8 | <dl§ | <dl§ | nd | nd | ||
| GA17 | 395 ± 13 | 109 ± 20 | <0.001 | nd | nd | |
| Non-13-OH GAs¶ | ||||||
| GA9 | 7.9 | 6.1 | nd | nd | ||
| GA4 | interference | interference | nd | nd | ||
| GA34 | 7.1 | 5.7 | nd | nd | ||
Contents estimated using calibration curves for all GAs except for GA17 (estimated from the peak area of ion 492 relative to the corrected peak area of ion 436 of deuterated GA19) and GA53 (estimated on the basis of corrected 448/450 peak areas). Values are mean ± SE of three (Doongara, Calrose, Calrose 76) or four (Kyeema) independent samples, except for GA8, GA9, and GA34, which are single determinations.
Probability (t test) that the difference between the means is due to chance.
GAs are shown in metabolic order except for GA17, a tricarboxylic acid, which represents a branch off the biosynthetic pathway from GA19. GA1 is the only bioactive GA in this sequence.
Endogenous GA8 was below the detection limit.
GA9, GA4, and GA34 are equivalent to GA20, GA1, and GA8 in the 13-OH GAs. GA4 was not determined because interfering ions were present.