超富集植物对重金属耐受和富集机制的研究进展闫 研 李建平 赵志国 林庆宇(505) 狭叶香蒲吸收Cd2+的动力学特征

The kinetics characteristic of Cd2+ absorption of Typha angustifolia

关键词:  狭叶香蒲  Cd²⁺  离子吸收动力学  动力学参数

Key words:  Typha angustifolia  Cd²⁺  kinetics of ion absorption  kinetic parameters

摘要:

采用水培方法,加入Cd²⁺浓度为0、0.2、0.4、0.6、1、1.2、1.5 mg·L^-1,分别在4、8、12、24 h研究狭叶香蒲幼苗吸收Cd²⁺的动力学特征。结果表明,狭叶香蒲对Cd²⁺的吸收基本符合Michaelis-Menten动力学模型。在上述几个时间段中,以0～4 h时间段内狭叶香蒲对Cd²⁺吸收的最大吸收速率V_max最大,K_m最小,α值也最大,此时根系吸收能力最强。随时间的延长(4～24 h),V_max变小,但是净吸收速率V仍在增加。用V-C作图法和L-B作图法求解动力学参数结果差异不大,且两种方法曲线模拟的相关性均较好。

Abstract:

Cd²⁺ concentration of 0,0.2,0.4,0.6,1.0,1.2,and 1.5 mg·L^-1were added in hydroponic culture solution to Typha angustifolia plants,and the Kinetics characteristic of Cd²⁺ absorption of them were studied separately at 4 h,8 h,12 h,and 24 h. Results indicated that the Cd²⁺ absorption of T.angustifolia conformed to Michaelis-Menten Kinetics model in the main. Among the before time periods,in 0-4 h time period,the maximum absorption rate V_max of T.angustifolia was the highest,the K_m was the lowest,and the α value was the highest,it showed that the root absorption ability was the strongest. With the time extending(4-24 h),the V_max decreased,but the completely absorption rate still increased. The kinetic parameters value obtained by V-C construction method and L-B construction method differed insignificantly,and the relativity of the curve imitated by the two methods all were good.