增强UV-B辐照对小麦幼苗叶肉细胞内Ca2＋水平的研究

以小麦（Triticum aestivum）幼苗叶片为材料,利用提取原生质体方法在小麦幼苗叶肉细胞中成功地装载了钙离子荧光指示剂fluo-3/AM,采用激光共聚焦显微技术检测了增强UV-B辐射后小麦幼苗叶肉细胞内游离钙离子荧光强度的分布,并对[Ca2＋];进行了测定.结果显示,对照组细胞内钙离子荧光分布较均匀,主要分布于紧贴质膜处和核周围,UV-B辐射组钙离子荧光与对照组分布相似,但其原生质体表面不如对照组平滑;同时发现增强UV-B辐射组细胞内钙离子荧光强度值较对照组高,说明增强UV-B辐射组小麦幼苗叶肉细胞维持较高浓度的钙离子水平.这些变化表明Ca2＋信号有可能以一定的方式参与了小麦响应UV-B辐射胁迫的过程.

Study on calcium ion inmesophyll of wheat seedlings exposed to enhanced ultraviolet-B radiation

In this paper, the wheat seedlings leaves were taken as materials. Fluorescent probe fluo-3/AM was loaded into the mesophyllprotoplast of wheat seedlings. The features of intracellular calcium distribution were studied and intraceIlular calcium ion concentration was measured by the laser scanning confocal microtechnique. The results showed that the fluorescence of cytoplasmic calcium ion distributed uniformly and mainly in plasma membrane or around the nucleus in control group（CK）. The distribution of fluorescence in UV-B radiation group was similar with CK, but protoplast surface was not smooth. The fluorescence intensity was higher than that of CK. It demonstrated that the wheat mesophyU ceils maintain a high level of concentration of calcium ions in enhanced UV-B radiation group. It suggested that the Ca2＋ signals beinvolved in the process which wheat response to the stress of UV-B radiation by a certain way.