title: Screening of a new cadmium hyperaccumulator, Galinsoga parviflora, from winter farmland weeds using the artificially high soil cadmium concentration method.
abstract: A new method, the artificially high soil cadmium (Cd) concentration method, was used to screen for Cd hyperaccumulators among winter farmland weeds. Galinsoga parviflora was the most promising remedial plant among 5 Cd accumulators or hyperaccumulators. In Cd concentration gradient experiments, as soil Cd concentration increased, root and shoot biomass decreased, and their Cd contents increased. In additional concentration gradient experiments, superoxide dismutase and peroxidase activities increased with soil Cd concentrations up to 75 mg kg(-1) , while expression of their isoenzymes strengthened. Catalase (CAT) activity declined and CAT isoenzyme expression weakened at soil Cd concentrations less than 50 mg kg(-1) . The maxima of Cd contents in shoots and roots were 137.63 mg kg(-1) and 105.70 mg kg(-1) , respectively, at 100 mg kg(-1) Cd in soil. The root and shoot bioconcentration factors exceeded 1.0, as did the translocation factor. In a field experiment, total extraction of Cd by shoots was 1.35 mg m(-2) to 1.43 mg m(-2) at soil Cd levels of 2.04 mg kg(-1) to 2.89 mg kg(-1) . Therefore, the artificially high soil Cd concentration method was effective for screening Cd hyperaccumulators. Galinsoga parviflora is a Cd hyperaccumulator that could be used to efficiently remediate Cd-contaminated farmland soil.
authors: College of Horticulture, Sichuan Agricultural University, Ya'an, Sichuan, China.
authors: Lijin
authors: L
authors: Lin
authors: Qian
authors: Q
authors: Jin
authors: Yingjie
authors: Y
authors: Liu
authors: Bo
authors: B
authors: Ning
authors: Ming'an
authors: M
authors: Liao
authors: Li
authors: L
authors: Luo
mesh_terms: D019659:Asteraceae / Q000378:metabolism*; D001673:Biodegradation, Environmental; D018533:Biomass; D002104:Cadmium / Q000032:analysis*; D019216:Metals, Heavy; D018517:Plant Roots / Q000378:metabolism; D018520:Plant Shoots / Q000378:metabolism; D012621:Seasons; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D019216:Metals, Heavy; D012987:Soil; D012989:Soil Pollutants; D002104:Cadmium; D013482:Superoxide Dismutase
keywords: Cadmium; Galinsoga parviflora; Hyperaccumulator; Remediation; Screening method