低温胁迫下凤眼莲叶片的适应——脱落酸和可溶性蛋白质含量升高

RESPONSE OF WATER HYACINTH LEAVES TO LOW TEMPERATURE STRESS——INCREASE IN ABSCISIC ACID AND SOLUBLE PROTEIN CONCENTRATIONS

本文报道低温胁迫下风眼莲叶片脱落酸(ABA)、可溶性蛋白质和水势的测定结果。低温胁迫时脱落酸和可溶性蛋白质含量远高于对照,(前者含量最高可达对照的4倍,后者可达到对照的2.75倍),而且脱落酸和蛋白质含量随温度降低而升高。蛋白质的生物合成抑制剂亚胺环己酮证明,可溶性蛋白质含量升高,原因是有部分是新合成的。在各种低温处理下获得了几乎相同于对照的叶片水势。我们推测:低温胁迫下,脱落酸水平的相应变化不是由于低温诱导水分胁迫所致,而是低温胁迫本身诱导。

To investigate the abscisic acid(ABA) production, soluble protein level and water potential of water hyacinth Eichhornia crassipes (Mart. Solms) leaves in response to diurnal low temperature stress, plants with 12 pieces of leaves were exposed to constant temperatures of 2, 4 and 8℃ for 72 hours and leaves were sampled at 0, 4, 24, 48 and 72 hours. ABA quantities were measured by using HPLC techniques. Lowry method was used to measure soluble and capillary method was used to measure water potential. Various low temperatures significantly increased ABA and soluble protein levels compariscd with control temperature (24—26℃), ABA and soluble protein increased with temperature decreasing. Cycloheximide was found to inhibit protein synthesis in the leaves at 2℃ more than at 24—26℃. Since normal water potentials were obtained in plants of all temperatures, the observed ABA response was not due to temperature-induced water stress. Temperature stress induced the plant to produce high level of ABA.