蔗糖调控培养对胡萝卜体细胞胚内源ABA水平的效应

Effects of Sucrose Regulation Culture on Endogenous ABA Levels of Carrot Somatic Embryo 

利用酶联免疫吸附测定（ＥＬＩＳＡ）技术，分析了经不同浓度蔗糖调控的胡萝卜（ＤａｕｃａｓｃａｒｏｔａＬ．）体细胞胚及胚性器官的内源ＡＢＡ水平。结果表明，随着胚的生长发育，内源ＡＢＡ含量呈上升趋势，到子叶胚时，达到最高值。在胚的早期发育阶段，不同处理之间，ＡＢＡ水平只有较小的差异，而当子叶胚开始膨大时，这种差异则较明显。一旦将调控胚解调控，体细胞胚内源ＡＢＡ含量则明显下降。在两个月内，调控胚及胚性器官的ＡＢＡ含量基本维持不变。表明蔗糖浓度可导致体胚内源ＡＢＡ水平的变化，但这种影响依发育时期而异；高浓度的ＡＢＡ水平有利于胚性状态的维持。与此同时，比较研究了外源ＡＢＡ处理效应与高浓度蔗糖处理的差异，结果表明，蔗糖的调控效应与ＡＢＡ的调控相似又不尽相同。总之，在蔗糖调控胡萝卜体细胞胚发育的信号传递网络中ＡＢＡ可能是一个重要的中介信号因子。

Endogenous ABA levels of carrot (Daucas carrota L.) somatic embryos and their organs were assayed under different sucrose concentration in MS media using ELISA. The results show that endogenous ABA level increases during the development of somatic embryo and reaches the highest at cotyledonary stage. ABA levels of somatic embryo vary little among different treatments at the early developing stage and more significantly when cotyledonary embryos grow bigger. ABA level decreases obviously once the regulated embryos is de_regulated in culture. The content of ABA in the regulated embryos and their organs maintain relatively unchanged in two months. These results imply that sucrose concentration in media induces the changes of ABA levels in the somatic embryo, and these changes are dependent to the different developing stages. High level of ABA in medium can maintain the embryo quiescence. Some difference still exist between the effects of exogenous ABA and those of high sucrose concentration on carrot somatic embryos. By and large, ABA probably acts as an important signal_mediated factor during the signal transduction of sucrose regulation on the development of somatic embryos in carrot.