title: Effects of extended growth periods on subcellular distribution, chemical forms, and the translocation of cadmium in Impatiens walleriana.
abstract: Impatiens walleriana plants accumulate sufficiently high concentrations of cadmium (Cd) for this species to be considered a potential Cd hyperaccumulator. Rooted cuttings were grown hydroponically for 25 and 50 days in solutions spiked with various Cd concentrations. The subcellular distribution and chemical forms of Cd in different organs were analyzed, and its upward translocation was also assessed. The plants accumulated large amounts of Cd; the Cd concentration in the roots and shoots reached 120-1900 and 60-1600 mg/kg, respectively. Regardless of the growth period, the Cd accumulated in the roots was primarily compartmentalized in the soluble fraction or ethanol and deionized water extractable chemical forms with high migration abilities. Translocation to the shoots was followed by an association of Cd mainly in the cell wall or with pectate and protein. The roots' Cd showed a high migration capacity for predicting the shoots' Cd concentrations. Different exposure periods significantly affected the subcellular distribution of Cd in the stems, and thus the upward translocation.
authors.affiliation: a Department of Post-Modern Agriculture , MingDao University , Peetow, Changhua County , Taiwan.
authors.forename: Hung-Yu
authors.initials: HY
authors.lastname: Lai
authors.affiliation: b Department of Materials and Energy Engineering , MingDao University , Peetow, Changhua County , Taiwan.
authors.forename: Ming-Cyuan
authors.initials: MC
authors.lastname: Cai
mesh_terms: D001673:Biodegradation, Environmental; D002104:Cadmium / Q000737:chemistry / Q000378:metabolism*; D029069:Impatiens / Q000737:chemistry / Q000254:growth & development* / Q000378:metabolism*; D008954:Models, Biological; D015394:Molecular Structure; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism; D018517:Plant Roots / Q000737:chemistry / Q000378:metabolism; D012989:Soil Pollutants / Q000737:chemistry / Q000378:metabolism*
chemical_list: D012989:Soil Pollutants; D002104:Cadmium
keywords: cadmium (Cd); chemical forms; impatiens; phytoremediation; subcellular distribution