抄録
The senescing process of the water compartments in gladiolus (Gladiolus×hybridus hort.cv. Fujinoyuki) flower petals were studied by evaluating the spin-lattice relaxation times (T_1) and the spin-spin relaxation times (T_2) using ^1H-NMR. The florets of cut gladiolus spikes showed severe wilting four days after flower opening, at 25℃ under 14L/10D conditions. Treatment with 0.1M trehalose suppressed petal senescence and prolonged its longevity by two more days. After four days, the first florets of trehalose-treated spikes maintained water more effectively than those treated with those placed in DW (distilled water) control. The changes in T_1 corresponded more closely to the water content and membrane integrity than those in T2. Furthermore, the semi-log plots of signal intensity of ^1H-NMR revealed that the water in the petal tissues consisted of at least two water components with T_1 values ranging over 1.2 s, and below about 0.7s respectively. The highly mobile water was considered to be free water derived from intact vacuoles. The free water in the petal tissues treated with DW disappeared after four days, while petals treated by trehalose maintained long T_1 values thus corresponding to significant water uptake in the petal tissues. These results suggested that trehalose helped to preserve cell viability and also enhanced the water uptake in petal tissues.
