Table I.
Concentrations of raffinose and loliose and activities of raffinose synthase in leaf tissues of perennial ryegrass subjected to 14 d of drought stress, followed by 14 d of rewatering
Values are means ± se (n = 3). Asterisk indicates significant differences between control and drought-stressed samples at P < 0.05. u.d.l., Under the detection limit; n.d., not determined.
| Leaf Tissue | d 0 | d 14 (End of Drought) | d 28 (End of Rewatering) | ||
|---|---|---|---|---|---|
| Control | Control | Drought-Stressed | Control | Drought-Stressed | |
| Raffinose (mg g-1 dry wt) | |||||
| Elongating leaf bases | u.d.l. | 0.33 ± 0.25 | 0.09 ± 0.21 | 0.01 ± 0.12 | 0.68 ± 0.14* |
| Leaf sheaths | 1.62 ± 0.35 | 0.34 ± 0.26 | 0.00 ± 0.14 | 0.88 ± 0.34 | 0.91 ± 0.23 |
| Leaf blades | 4.15 ± 0.23 | 1.56 ± 0.25 | 0.37 ± 0.56 | 1.46 ± 0.07 | 1.27 ± 0.77 |
| Raffinose synthase activity (nkat mg-1 proteins) | |||||
| Elongating leaf bases | 2.28 ± 0.89 | 2.93 ± 1.33 | 7.47 ± 2.37 | 2.80 ± 0.09 | 0.00 ± 0.87* |
| Leaf sheaths | 29.60 ± 7.27 | 20.46 ± 10.38 | 9.67 ± 4.43 | 20.74 ± 8.84 | 9.39 ± 6.58 |
| Leaf blades | n.d | n.d | n.d | n.d | n.d |
| Loliose (mg g-1 dry wt) | |||||
| Elongating leaf bases | u.d.l. | u.d.l. | u.d.l. | u.d.l. | u.d.l. |
| Leaf sheaths | 1.92 ± 0.71 | 0.60 ± 1.14 | 0.07 ± 0.35 | 1.49 ± 0.78 | u.d.l. |
| Leaf blades | u.d.l. | u.d.l. | u.d.l. | u.d.l. | u.d.l. |