title: Model optimization of cadmium and accumulation in switchgrass (Panicum virgatum L.): potential use for ecological phytoremediation in Cd-contaminated soils.
abstract: Soil pollution with heavy metals is an increasingly serious threat to the environment, food security, and human health. Therefore, it is urgent to develop economic and highly efficient soil restoration technology for environmental improvement; phytoremediation is an option that is safe, has low cost, and is environmentally friendly. However, in selecting hyperaccumulators or tolerant plants, theories and operation technologies for optimal restoration should be satisfied. In this study, the switchgrass growth response and performance of phytoextraction under the coupling effect of Cd and pH were investigated by evaluating seed germination, seedling growth, and the Cd content in the plant to evaluate the potential use of switchgrass as a phytoremediation plant in cadmium contaminated soil. This study conducted three sets of independent experiments with five levels of Cd concentrations, including two orthogonal matrix designs of combining Cd with pH values. The results showed that switchgrass was germinated well under all treatments (Cd concentration of 0-500 μM), but the seedling growth was significantly affected by Cd and pH, as shown by multivariate regression analyses. Hormesis was found during the growth of switchgrass plants exposed to low Cd concentrations under hydroponic conditions, and switchgrass plants were capable of developing with a Cd concentration of 100-175 μM and pH of 4.1-5.9. Mild acidic conditions can enhance the ability of Cd to accumulate in switchgrass. Switchgrass was moderately tolerant to Cd and may be used as a phytoremediation plant for Cd-contaminated soils in the future. Our results also suggest that hormetic effects should be taken into consideration in the phytoremediation of Cd-contaminated soils. We discuss the physiological and biochemical mechanisms contributing to the effective application of the plant for the phytoremediation of Cd-contaminated soils.
authors.affiliation: Department of Grassland Science, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi Province, People's Republic of China. wangquanzhen191@163.com.
authors.forename: Quanzhen
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Grassland Science, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi Province, People's Republic of China.
authors.forename: Muyu
authors.initials: M
authors.lastname: Gu
authors.affiliation: Department of Grassland Science, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi Province, People's Republic of China.
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Ma
authors.affiliation: Department of Grassland Science, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi Province, People's Republic of China.
authors.forename: Hongjuan
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Grassland Science, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi Province, People's Republic of China.
authors.forename: Yafang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Institute of Plant Science, College of life Science, Northwest A&F University, Yangling, 712100, Shaanxi Province, People's Republic of China.
authors.forename: Jian
authors.initials: J
authors.lastname: Cui
authors.affiliation: Department of Grassland Science, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi Province, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Gao
authors.affiliation: Department of Grassland Science, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi Province, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Gui
mesh_terms: D001673:Biodegradation, Environmental; D002104:Cadmium / Q000302:isolation & purification* / Q000378:metabolism* / Q000633:toxicity; D004463:Ecology; D018525:Germination / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D008954:Models, Biological; D008897:Panicum / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000302:isolation & purification* / Q000378:metabolism* / Q000633:toxicity
chemical_list: D012987:Soil; D012989:Soil Pollutants; D002104:Cadmium
keywords: Cadmium accumulation; Cd-contaminated soils; Model optimization; Phytoremediation; Switchgrass