ANALYSIS OF WATER BALANCE IN CUT FLOWERS OF BULBOUS PLANTS AT GROWING AND SENESCING STAGES

点击翻译按钮获取中文摘要

Water status of cut bulbous flowers was determined by ^1H-NMR spectroscopy and isopiestic psychrometers at growing and senescing stages. Treatment with trehalose was markedly effective in prolonging vase life in gladiolus and tulip flowers. Long ^1H-NMR relaxation time (T_1) of the intracellular water in petal tissues for both species showed that trehalose functioned to protect vacuolar water. Short T_2s estimated as bound water from cytoplasm and the apoplastic regions were determined by solid echo technique. In cut flowers, trehalose maintained a higher degree of water content accompanying with suppressing protein degradation and turgor loss than control petal tissues with protecting membrane integrity during growing and senescence stages. On the other hand, trehalose did not promote elongation of epidermal parenchyma cells in tulip tepal tissues, but maintained radial enlargement of the cells. Additionally, the hydraulic conductance of soybean embryos grown on trehalose-containing media became smaller than that in sucrose-containing media, suggesting that trehalose might reduce hydraulic conductance in soybean embryos, resulting in growth retardation of soybean embryos. From these results, trehalose did not act as an energy source or directly participate in osmoregulation and these characteristics distinguish it from other sugars such as sucrose.