Effects of cadmium on plant growth and physiological traits in contrast wheat recombinant inbred lines differing in cadmium tolerance.
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.
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.
Dunwei
D
Ci
Dong
D
Jiang
Tingbo
T
Dai
Qi
Q
Jing
Weixing
W
Cao
D002104:Cadmium / Q000633:toxicity*; D002374:Catalase / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D004361:Drug Tolerance; D005453:Fluorescence; D008315:Malondialdehyde / Q000378:metabolism; D045332:Photosystem II Protein Complex / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development; D011995:Recombination, Genetic; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development; D012989:Soil Pollutants / Q000633:toxicity*; D013482:Superoxide Dismutase / Q000378:metabolism; D014908:Triticum / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*
D045332:Photosystem II Protein Complex; D012989:Soil Pollutants; D002104:Cadmium; D002734:Chlorophyll; D008315:Malondialdehyde; D002374:Catalase; D013482:Superoxide Dismutase; D000077194:Chlorophyll A