Ca2+对Cd2+胁迫下板蓝根种子萌发及幼苗抗氧化酶活性的影响

研究了Cd²⁺（10 mg·L^-1、30 mg·L^-1）胁迫下不同浓度Ca²⁺（0、80、160、320 mg·L^-1）对板蓝根种子萌发、幼苗抗氧化酶系统及蛋白质含量的影响。结果表明：低浓度Ca²⁺（80、160 mg·L^-1）可缓解Cd²⁺毒害，显著提高板蓝根种子的发芽率、发芽势、发芽指数、活力指数，促进蛋白质含量的增加，提高SOD、POD、CAT活性，且160　mg·L^-1 Ca²⁺缓解效果最好，缓解能力随Cd²⁺浓度的升高有所下降；高浓度Ca²⁺（320 mg·L^-1）与Cd²⁺作用,反而抑制了板蓝根种子的萌发，幼苗的POD、SOD、CAT活性及蛋白质含量下降。低浓度Ca²⁺可以显著提高板蓝根的抗性，对Cd²⁺毒害起缓解作用，高浓度的Ca²⁺与Cd²⁺对板蓝根种子起协同毒害作用。

The effect of Ca2+ on Radix isatidis seed germination and seedling physiological characteristics under Cd2+ stress

This study aims to investigate the effect of different Ca²⁺ levels (0, 80, 160 mg·L^-1 and 320 mg·L^-1) on seed germination, activities of SOD, POD, and CAT, and protein content of Radix Isatisdis seedlings under different Cd²⁺ stress le vels (10 mg·L^-1 and 30 mg·L^-1). The results show that low concentration of Ca²⁺, especially the concentration of 160 mg·L^-1, may mitigate the deleterious effect of Cd²⁺ by increasing germination rate and vigour index, and enhancing activities of SOD, POD, and CAT, and increasing protein content. The influence of Ca²⁺ on the Cd2+ toxicity was not obvious at high Cd²⁺ concentration because of the inhibition of the above indexes. These results suggest that the low concentration of Ca²⁺ could be favorable for coping with Cd²⁺ toxicity, whereas high concentration of Ca²⁺ shows synergistic effect with Cd²⁺ for Radix Isatisdis.