title: Bioaccumulation and detoxification mechanisms for lead uptake identified in Rhus chinensis Mill. seedlings.
abstract: A greenhouse experiment was conducted to assay the bioaccumulation and tolerance characteristics of Rhus chinensis Mill. to lead (Pb). The effects of exposing R. chinensis Mill seedlings to increasing Pb concentrations (0, 250, 500, 100mgkg-1) in the soil were assessed by measuring Pb accumulation, subcellular distribution, ultrastructure, photosynthetic characteristics, antioxidative enzyme activity, malondialdehyde content, and phytochelatin content. The majority of Pb taken up by R. chinensis Mill was associated with the cell wall fraction in the roots, where the absorption of Ca increased to maintain cell wall stability, and Pb deposits were found in the intercellular space or in the cell wall structures. In leaves, Pb was primarily stored in the cell wall, while it was compartmentalized into the vacuolar structures in the stem. Pb concentrations adversely affected the morphology of Rhus chinensis Mill cellular substructures. Furthermore, increased Peroxidase (POD) and catalase (CAT) activity was observed in plants grown in Pb-amended soil, and this may have led to reduced ROS to maintain the function of the membrane. Changes in phytochelatin levels (PCs) that were observed in Pb treated plants suggest that PCs formed complexes with Pb in the cytoplasm to reduce Pb2+toxicity in the metabolically active cellular compartment. This mechanism may allow for the plant to accumulate higher concentrations of toxic Pb and survive for a longer period of time. Our study provides a better understanding of how Rhus chinensis Mill detoxifies Pb.
authors.affiliation: College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350002, China. Electronic address: zhouchuifan@163.com.
authors.forename: Chuifan
authors.initials: C
authors.lastname: Zhou
authors.affiliation: College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
authors.forename: Meiying
authors.initials: M
authors.lastname: Huang
authors.affiliation: Institute of Land Reclamation and Econlogy, China University of Mining and Technology Beijing, 100120, China; Beijing Huayu Engineering Company Limited, China Coal Technology and Engineering Group, Beijing 100120, China.
authors.forename: Huijun
authors.initials: H
authors.lastname: Ren
authors.affiliation: College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
authors.forename: Jiaoda
authors.initials: J
authors.lastname: Yu
authors.affiliation: College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
authors.forename: Jiamei
authors.initials: J
authors.lastname: Wu
authors.affiliation: College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350002, China. Electronic address: lxymxq@126.com.
authors.forename: Xiangqing
authors.initials: X
authors.lastname: Ma
mesh_terms: D001673:Biodegradation, Environmental; D002473:Cell Wall / Q000187:drug effects / Q000378:metabolism; D002681:China; D008658:Inactivation, Metabolic; D007854:Lead / Q000378:metabolism / Q000633:toxicity*; D008315:Malondialdehyde / Q000378:metabolism; D010788:Photosynthesis / Q000187:drug effects; D054811:Phytochelatins / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D018547:Plant Stems / Q000187:drug effects / Q000378:metabolism; D029045:Rhus / Q000187:drug effects* / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects* / Q000378:metabolism; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000378:metabolism / Q000633:toxicity*
chemical_list: D012987:Soil; D012989:Soil Pollutants; D007854:Lead; D008315:Malondialdehyde; D054811:Phytochelatins
keywords: Antioxidative enzyme activity; Lead stress; Subcellular distribution; Ultrastructure