在蔗糖预培养诱导耐脱水性过程中黄皮胚轴的水分状态和可溶性蛋白含量的变化

逐步增加培养基的蔗糖浓度可提高黄皮胚轴的耐脱水性。用差示扫描量热仪（DSC）和SDS—PAGE方法探讨了黄皮胚轴在耐脱水性获得过程中的水分状态和可溶性蛋白的变化。DSC图谱显示，蔗糖预培养胚轴的升温图谱与对照不同，有比较明显的台阶式变化，有玻璃化形成的倾向；应用线性回归方程法或冰熔化热法计算黄皮胚轴的不可冻结水，发现蔗糖预培养胚轴的不可冻结水含量与对照胚轴无显著差异。蛋白分析表明，蔗糖预培养诱导黄皮胚轴中可溶性蛋白增加68％，其中尤以20kD蛋白的增幅最大。

Changes in Water State and Soluble Protein Contents of Wampee Axes during Inducing Desiccation Tolerance by Sucrose Preculture

Progressively increasing sucrose con-centration of culture medium could increase des-iccation tolerance of wampee Clausena lansium(Lour.) Skeels] axes. The changes in water stateand soluble proteins of axes during acquirementof desiccation tolerance were measured by differ-ential scanning calorimeter (DSC) and SDS-PAGE.The results showed that the cooling and heatingthermograms of sucrose-precultured axes weresimilar to those of the control (Fig.1, Fig.2); butthere was a stepwise change in the heating ther-mograms of sucrose-precultured axes, implyingthat vitrification might occur in axes (Fig.2).Unfreezable water amounts of wampee axes weremeasured, the results showed that amounts ofunfreezable water of sucrose-precultured axes andcontrol were 25.4% and 25.9% (Table 1, by thelinear regression equation method), or 24.3% and23.7% (by the heat of ice fusion method)respectively, which were not significantly different.The soluble protein content of sucrose-preculturedaxes was 68% higher than the control, and SDS-PAGE showed that a 20-kD protein markedly in-creased in content (Fig.3).