Key Laboratory of Crop Physiology and Ecology in Southern China, Ministry of Agriculture/Hi-Tech Key Laboratory of Information Agriculture of Jiangsu Province, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, P.R. China.
Chemosphere. 2009 Dec;77(11):1620-5. doi: 10.1016/j.chemosphere.2009.08.062. Epub 2009 Sep 23.
Four wheat (Triticum aestivum L.) lines differing in cadmium (Cd) tolerance previously identified from a recombinant inbred line population were subjected to 50 microM CdCl2 from the three-leaf stage for 24 d, to investigate the responses of wheat seedlings to Cd toxicity. Under Cd stress, most growth parameters and root morphological traits were reduced, except for secondary root numbers and average root diameter. Cd enhanced leaf cell peroxidation due to increased malondialdehyde (MDA) content and reduced activities of superoxide dismutase (SOD) and catalase (CAT) in leaves. In addition, CAT activity decreased in the Cd-sensitive lines while increased in the tolerant lines. Leaf photosystem II (PSII) was damaged, since the maximum efficiency of PSII photochemistry (Fv/Fm) and potential efficiency of PSII photochemistry under dark-adapted (Fv/Fo) decreased, while the initial fluorescence (Fo) increased in all lines under Cd stress. Then, total soluble sugar concentration decreased while free amino acids concentration increased in both shoot and root. We concluded that Cd-tolerant lines accumulated less Cd in plant and contained low Cd concentration in shoot (less translocation of Cd to shoot), maintained higher CAT activity in leaf and higher PS II function than the Cd-sensitive lines under Cd toxicity, thus could be related to their tolerant capacity to Cd in the present study.
四种先前从重组自交系群体中鉴定出的耐镉小麦（Triticum aestivum L.）品系在三叶期用 50 μM CdCl2 处理 24 d，以研究小麦幼苗对镉毒性的反应。在镉胁迫下，大多数生长参数和根形态特征都降低了，除了次生根数量和平均根直径。由于叶片中丙二醛（MDA）含量增加和超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性降低，Cd 增强了叶片细胞的过氧化作用。此外，Cd 敏感系中的 CAT 活性降低，而耐系中的 CAT 活性增加。叶片光系统 II（PSII）受到损伤，因为最大光化学效率（Fv/Fm）和暗适应下光化学效率的潜在效率（Fv/Fo）降低，而所有系在 Cd 胁迫下的初始荧光（Fo）增加。然后，总可溶性糖浓度在地上部和根部都降低，游离氨基酸浓度增加。我们得出结论，耐 Cd 系在植物中积累的 Cd 较少，地上部的 Cd 浓度较低（向地上部的 Cd 转运较少），在 Cd 毒性下叶片中的 CAT 活性和 PS II 功能较高，因此可能与它们在本研究中的 Cd 耐受能力有关。
