Cadmium tolerance in Brassica juncea roots and shoots is affected by antioxidant status and phytochelatin biosynthesis.

来自 dx.doi.org

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阅读量：

231

作者：

AA Mohamed，A Castagna，A Ranieri，LSD Toppi

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摘要：

Indian mustard (Brassica juncea L. Czern.) tolerates high concentrations of heavy metals and is a promising species for the purpose of phytoextraction of cadmium (Cd) from metal-contaminated soils. This work investigates the extent to which antioxidant and metal sequestering mechanisms are responsible for this tolerance. To this end, seedlings of Indian mustard were grown for 7 days in 0, 50 or 200μM Cd. Increasing Cd concentrations led to a progressive Cd accumulation in roots and shoots, accompanied by an organ-dependent alteration in mineral uptake, and a decrease in root/shoot length and fresh/dry weight. Cd negatively affected chlorophyll and carotenoid contents and activated the xanthophyll cycle, suggesting the need to protect the photosynthetic apparatus from photoinhibition. Shoots seemed to be less efficient than roots in ROS scavenging, as indicated by the different response to Cd stress shown by peroxidase and catalase activities and, solely with regard to the highest Cd concentration, by ascorbate level. Such a different antioxidant capacity might at least partly explain differences in the trend of lipid peroxidation observed in the two organs. Moreover, in both roots and shoots, glutathione and phytochelatin content markedly increased under Cd stress, regardless of the metal concentration involved.

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关键词：

Cd Chlorophyll Glutathione Lipid peroxidation Oxidative stress Photosynthesis Phytochelatins

DOI：

10.1016/j.plaphy.2012.05.002

被引量：

208

年份：

2012