Department of Plant Science, University of Alberta, Edmonton, Alberta, Canada T6G 2P5.
Plant Physiol. 1991 Apr;95(4):1044-8. doi: 10.1104/pp.95.4.1044.
Brassica napus suspension-cultured cells could be hardened in 6 days at 25 degrees C by the addition of mefluidide or ABA to the culture medium. Cells treated with mefluidide (10 milligrams per liter) or ABA (50 micromolar) attained an LT(50) of -17.5 degrees C or -18 degrees C, respectively, while the LT(50) for the comparable nonhardened control (sucrose) was -10 degrees C. The increased freezing tolerance of mefluidide-treated cells was paralleled by a 4- to 23-fold increase in ABA, as measured by gas-liquid chromatography using electron capture detection. Application of 1 milligram per liter of fluridone, an inhibitor of abscisic acid biosynthesis, prevented the mefluidide-induced increase in freezing tolerance and the accumulation of ABA. Both these inhibitory effects of fluridone were overridden by 50 micromolar ABA in the culture medium. On the basis of these results, we concluded that increased ABA levels are important for the induction of freezing tolerance in suspension-cultured cells.
油菜悬浮培养细胞在 25℃下经培养基中添加抑芽丹或 ABA 处理 6 天即可硬化。用抑芽丹（10 毫克/升）或 ABA（50 微摩尔）处理的细胞的 LT（50）分别达到-17.5℃或-18℃，而可比的非硬化对照（蔗糖）的 LT（50）为-10℃。用电子捕获检测的气液色谱法测定，抑芽丹处理细胞的抗冻性增强与 ABA 增加 4 至 23 倍平行。用 1 毫克/升的氟啶酮（一种 ABA 生物合成抑制剂）处理可防止抑芽丹诱导的抗冻性增强和 ABA 积累。氟啶酮的这两种抑制作用均可被培养基中的 50 微摩尔 ABA 克服。根据这些结果，我们得出结论，ABA 水平的增加对于悬浮培养细胞抗冻性的诱导很重要。
