Sun Rui-lian, Zhou Qi-xing, Wang Xin
Key Laboratory of Terrestrial Ecological Process, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
Huan Jing Ke Xue. 2006 Apr;27(4):765-9.
The influence of different cadmium concentrations on the organic acid level in leaves of the Cd hyperaccumulator, Solanum nigrum L., in particular, the relationship of organic acids with Cd accumulation in S. nigrum was investigated based on the pot-culture experiment. The results showed that the Cd concentration in S. nigrum leaves exceeded 100 microg x g(-1), the threshold value used to define Cd-hyperaccumulators, and the bioaccumulation coefficient of cadmium in shoots of S. nigrum was higher than 1 when Cd concentration in soil was 25 microg x g(-1). The level of organic acids in leaves of S. nigrum had significant differences between the seedling stage and the mature stage. At the seedling stage, the sequence of organic acids in leaves of S. nigrum was acetic acid> tartaric acid> malic acid> citric acid. On the contrary, the accumulation of organic acids in S. nigrum at the mature stage was approximately in the following sequence malic acid> tartaric acid, acetic acid> citric acid. The significant positive correlation between Cd accumulation in leaves of S. nigrum and the concentration of tartaric acid in leaves of S. nigrum was observed at the seedling stage, whereas there was a significant positive correlation between Cd accumulation in leaves of S. nigrum and both acetic and citric acid concentrations at the mature stage. These results indicated that tartaric, acetic and citric acids in leaves of S. nigrum might act as the indication of Cd hyperaccumulation.
基于盆栽试验，研究了不同镉浓度对镉超富集植物龙葵叶片中有机酸含量的影响，特别是有机酸与龙葵镉积累之间的关系。结果表明，当土壤镉浓度为25μg x g(-1)时，龙葵叶片中的镉浓度超过了用于定义镉超富集植物的阈值100μg x g(-1)，且龙葵地上部镉的生物富集系数高于1。龙葵叶片中有机酸含量在苗期和成熟期存在显著差异。在苗期，龙葵叶片中有机酸的顺序为乙酸>酒石酸>苹果酸>柠檬酸。相反，成熟期龙葵中有机酸的积累顺序大致为苹果酸>酒石酸，乙酸>柠檬酸。在苗期观察到龙葵叶片中镉积累与酒石酸浓度之间存在显著正相关，而在成熟期龙葵叶片中镉积累与乙酸和柠檬酸浓度均存在显著正相关。这些结果表明，龙葵叶片中的酒石酸、乙酸和柠檬酸可能作为镉超积累的指示物。
