RICE SCIENCE ›› 2007, Vol. 14 ›› Issue (3): 217-222 .

• Research Paper • Previous Articles     Next Articles

Cadmium Accumulation and Its Toxicity in Brittle Culm 1 (bc1), a Fragile Rice Mutant

SHAO Guo-sheng 1, 2, CHEN Ming-xue 1, ZHANG Xiu-fu 1, XU Chun-mei 1, WANG Dan-ying 1, QIAN Qian 1, ZHANG Guo-ping 2   

  1. 1 China National Rice Research Institute, Hangzhou 310006, China; 2 College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310029, China
  • Received:2007-06-08 Online:2007-09-28 Published:2007-09-28
  • Contact: ZHANG Guo-ping
  • Supported by:
    the National Natural Science Foundation of China (Grant No. 30600379),Zhejiang Natural Science Foundation (Grant No.Z304104) and the Research Funds for National Nonprofit Research Institution (Grant No. CNRRI10023)for their financial support.

Abstract: Cadmium (Cd) accumulation and toxicity in rice plants were characterized and identified by using brittle culm 1 (bc1), a fragile rice mutant and its wild type (Shuangkezao, an indica rice) as materials by hydroponics. The low Cd level didn’t obviously affect the growth parameters in both rice genotypes, but under high Cd levels (1.0 and 5.0 μmol/L), the growth of both rice plants were substantially inhibited. Moreover, bc1 tended to suffer more seriously from Cd toxicity than Shuangkezao. Cd accumulation in both rice plants increased with the increase of Cd levels. There was a significant difference in Cd accumulation between the two rice genotypes with constantly higher Cd concentration in bc1, which also accumulated more Cd at 0, 0.1, and 1.0 μmol/L Cd levels. The same case was found in the two rice plants grown on Cd-contaminated soil. This suggested that cell wall might play an important role in Cd accumulation in rice plants by the physiological mechanisms. The malondialdehyde (MDA) content, superoxide dismutase (SOD) and peroxidase (POD) activities in rice plants were affected differently under Cd treatments, and which implied that POD might play the main role in detoxifying active oxygen free radical. A significant difference in antioxidative system between the two rice genotypes was found with constantly higher MDA content, SOD and POD activities in bc1. In summary, bc1 accumulated more Cd and appeared to be more sensitive to Cd stress compared with its wild type.

Key words: rice (Oryza sativa), cadmium, brittle culm mutant, malondialdehyde, oxidative stress, toxicity, superoxide dismutase, peroxidase, active oxygen free radical, enzyme activity