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.