Laboratory of Plant Biotechnology, Faculty of Sciences, University of Sfax, BP 1171, 3000, Sfax, Tunisia.
Environ Sci Pollut Res Int. 2015 Jul;22(14):10679-89. doi: 10.1007/s11356-015-4270-8. Epub 2015 Mar 11.
The bioaccumulation efficiency of cadmium (Cd) by fenugreek (Trigonella foenum-graecum) was examined using different concentrations of CdCl2. The germination rate was similar to control except at 10 mM Cd. However, early seedling growth was quite sensitive to the metal from the lowest Cd level. Accordingly, amylase activity was reduced substantially on treatment of seeds with 0.5, 1, and 10 mM Cd. Cadmium also affected various other plant growth parameters. Its accumulation was markedly lower in shoots as compared to roots, reducing root biomass by almost 50 %. Plants treated with 1 and 5 mM Cd presented chlorosis due to a significant reduction in chlorophyll b especially. Furthermore, at Cd concentrations greater than 0.1 mM, plants showed several signs of oxidative stress; an enhancement in root hydrogen peroxide (H2O2) level and in shoot malondialdehyde (MDA) content was observed. Conversely, antioxidant enzyme activities (superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT)) increased in various plant parts. Likewise, total phenolic and flavonoid contents reached their highest values in the 0.5 mM Cd treatment, consistent with their roles in quenching low concentrations of reactive oxygen species (ROS). Consequently, maintaining oxidant and antioxidant balance may permit fenugreek to hyperaccumulate Cd and allow it to be employed in extremely Cd polluted soils for detoxification purposes.
利用不同浓度的 CdCl2 研究了葫芦巴（Trigonella foenum-graecum）对镉（Cd）的生物积累效率。发芽率与对照相似，除了在 10mM Cd 时。然而，早期幼苗的生长对金属非常敏感，即使在最低 Cd 水平下也是如此。因此，用 0.5、1 和 10mM Cd 处理种子会大大降低淀粉酶活性。镉还影响其他各种植物生长参数。与根相比，其在地上部分的积累明显较低，根生物量减少近 50%。用 1 和 5mM Cd 处理的植物由于叶绿素 b 显著减少而出现黄化现象。此外，在 Cd 浓度大于 0.1mM 时，植物表现出多种氧化应激迹象；观察到根过氧化氢（H2O2）水平和茎丙二醛（MDA）含量增加。相反，抗氧化酶活性（超氧化物歧化酶（SOD）、抗坏血酸过氧化物酶（APX）和过氧化氢酶（CAT））在植物各部分增加。同样，总酚和类黄酮含量在 0.5mM Cd 处理下达到最高值，这与其在淬灭低浓度活性氧（ROS）中的作用一致。因此，维持氧化剂和抗氧化剂的平衡可能使葫芦巴能够超积累 Cd，并允许其在极度 Cd 污染的土壤中用于解毒目的。
