Physiological responses and detoxific mechanisms to Pb,Zn,Cu and Cd in young seedlings of Paulownia fortunei  

作　　者：Jiang Wang Weihua Li Chongbang Zhang Shisheng Ke 

机构地区：[1]School of Life Sciences, Taizhou University, Linhai 317000, China [2]Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, College of Life Sciences, South China Normal University, Guangzhou 510631, China

出　　处：《Journal of Environmental Sciences》2010年第12期1916-1922,共7页环境科学学报（英文版）

基　　金：supported by the Natural Science Foundation of Zhejiang Province,China(No. Y5100016);the Science Foundation of Taizhou University(No.2010PY26)

摘　　要：Paulownia fortunei has been successfully used in the phytoremediation of many Pb/Zn mine tailings. However, seed germination and young seedlings of P. fortunei rarely occurred in these mine tailings. The physiological responses and detoxific mechanisms of P. fortunei young seedling to Pb, Zn, Cu and Cd stress were investigated. The germinated rate, shoot length, chlorophyll and carotenoid contents in leaves of young seedlings had a great reduction under Zn and Cu treatments, but had little decrease under Pb and Cd treatments. The production rate of O2＊-, H2O2 and malondialdehyde （MDA） contents significantly increased in response to added Zn and Cu indicating great oxidative stress for young seedlings, but they had no significant change to added Pb and Cd. Young seedlings had effective detoxific mechanism to Pb and Cd, as antioxidant enzymes activities, phytochelatins （PCs-SH） and proline contents increased with increasing rates of added Pb and Cd. However, young seedlings had un-effective detoxific mechanisms to Zn and Cu stress. Results revealed the heavy metals （such as Ca） that present at low concentrations in mine tailings may be major constraint for the survival of young seedlings.Paulownia fortunei has been successfully used in the phytoremediation of many Pb/Zn mine tailings. However, seed germination and young seedlings of P. fortunei rarely occurred in these mine tailings. The physiological responses and detoxific mechanisms of P. fortunei young seedling to Pb, Zn, Cu and Cd stress were investigated. The germinated rate, shoot length, chlorophyll and carotenoid contents in leaves of young seedlings had a great reduction under Zn and Cu treatments, but had little decrease under Pb and Cd treatments. The production rate of O2＊-, H2O2 and malondialdehyde （MDA） contents significantly increased in response to added Zn and Cu indicating great oxidative stress for young seedlings, but they had no significant change to added Pb and Cd. Young seedlings had effective detoxific mechanism to Pb and Cd, as antioxidant enzymes activities, phytochelatins （PCs-SH） and proline contents increased with increasing rates of added Pb and Cd. However, young seedlings had un-effective detoxific mechanisms to Zn and Cu stress. Results revealed the heavy metals （such as Ca） that present at low concentrations in mine tailings may be major constraint for the survival of young seedlings.

关 键 词：heavy metals defense system oxygen species antioxidant enzyme PHYTOCHELATINS 

分 类 号：S642.2[农业科学—蔬菜学] TS255.44[农业科学—园艺学]