铈在水鳖叶中的亚细胞分布、赋存形态及毒理效应分析

以不同浓度Ce培养4 d的水鳖为实验材料,分析了Ce在各亚细胞组分中的分布、赋存形态及对矿质营养吸收、活性氧产生和非酶促保护系统的影响。研究表明:Ce在各亚细胞组分中的分布顺序为细胞壁>细胞器>可溶性部分;Ce在水鳖叶细胞内主要以紧密结合态存在;Ce明显导致水鳖矿质营养失衡;随着培养液中Ce浓度的增加,水鳖叶片中的H2O2含量和O2.-产生速率都显著上升,活性氧的积累可作为Ce胁迫的敏感指标;AsA含量随Ce浓度的升高显著增加,而GSH含量无明显变化;5～10 mg.L-1Ce能诱导PCs和NPT大量合成,20 mg.L-1虽开始下降,但仍高于正常水平。

Subcellular Distribution, Chemical Forms and Phytotoxity of Cerium in Hydrocharis Dubia

Subcellular distribution,chemical forms of Ce and its influence on mineral nutrients,the ROS generation and non-enzymatic antioxidants of Hydrocharis dubia exposed to various concentration of Ce for 4 d were investigated.It was found that the accumulation of Ce in subcellular fractions decreased in the order of cell wall>organelle>soluble fraction;Ce mainly existed in the tightly bound form;Ce resulted in serious imbalance of nutrient elements;The H2O2 content and the generating rate of O.-2 exhibited drastically escalating trend with the rise of Ce concentration in the culture medium.ROS accumulation could be served as a sensitive indicator to Ce stress;AsA level dramatically enhanced with Ce level increasing,while GSH content showed an unobvious variation;The amount of NPT and PCs simultaneously augmented evidently with lower Ce concentration(5~10 mg · L-1) and followed by a hardly decline when the treatment concentration up to 20 mg · L-1,but it was still higher in comparison to control.