Institute of Plant Cell and Molecular Biology, College of Life Science, Nanjing Normal University, Nanjing, 210046, PR China. haiyanyang
Aquat Toxicol. 2010 Nov 1;100(3):282-8. doi: 10.1016/j.aquatox.2010.07.026. Epub 2010 Aug 4.
The effects of increasing concentrations of cadmium (Cd) on the ultrastructure, Cd accumulation, generation of O(2)(-), contents of ascorbate (AsA), reduced glutathione (GSH) and polyamines (PAs), as well as the activities of polyamine oxidase (PAO) (EC 1.5.3.3) and diamine oxidase (DAO) (EC 1.4.3.6) were investigated in the leaves of Potamogeton crispus. Cd exposure resulted in significant damage in chloroplasts and mitochondria, suggesting that Cd hastened the senescence of the tested plants. The accumulation of Cd was found to increase in a concentration-dependent manner, accompanied by increased production of O(2)(-). AsA content increased progressively up to 70μM Cd, followed by a decline at higher concentration. GSH content slightly increased up to 70μM Cd and then declined. In addition, Cd treatment increased the putrescine (Put) content, while decreasing spermidine (Spd) and spermine (Spm) contents, which reduced the ratio of free (Spd+Spm)/Put in the leaves. PS-conjugated PAs changed in the same pattern as free PAs, while PIS-bound PAs was different. PIS-bound Put content enhanced with the increase of Cd concentration up to 50μM and then decreased, and PIS-bound Spd and Spm contents decreased to a lesser extent. Moreover, the activities of PAO and DAO increased significantly with the increase of the Cd concentrations, reaching the peak values at 70μM Cd. Our results suggested that certain PAs and PAs forms could play a significant role in the adaptation mechanism of P. crispus under Cd stress.
研究了镉（Cd）浓度增加对菹草叶片超微结构、Cd 积累、超氧阴离子（O2(-)）生成、抗坏血酸（AsA）、还原型谷胱甘肽（GSH）和多胺（PAs）含量以及多胺氧化酶（PAO）（EC 1.5.3.3）和二胺氧化酶（DAO）（EC 1.4.3.6）活性的影响。Cd 暴露导致叶绿体和线粒体明显损伤，表明 Cd 加速了受试植物的衰老。Cd 积累呈浓度依赖性增加，伴随着 O2(-)生成增加。AsA 含量在 70μM Cd 时逐渐增加，随后在更高浓度下下降。GSH 含量在 70μM Cd 时略有增加，随后下降。此外，Cd 处理增加腐胺（Put）含量，降低亚精胺（Spd）和精胺（Spm）含量，降低叶片游离（Spd+Spm）/Put 比值。PS 结合的 PAs 与游离 PAs 的变化模式相同，而 PIS 结合的 PAs 则不同。PIS 结合的 Put 含量随着 Cd 浓度的增加而增加，最高可达 50μM，然后下降，PIS 结合的 Spd 和 Spm 含量下降幅度较小。此外，PAO 和 DAO 的活性随着 Cd 浓度的增加而显著增加，在 70μM Cd 时达到峰值。我们的结果表明，在 Cd 胁迫下，某些 PAs 和 PAs 形式可能在菹草的适应机制中发挥重要作用。
