title: Long-distance transport of cadmium from roots to leaves of Solanum melongena.
abstract: In this study, the characteristics of cadmium (Cd) uptake by roots and translocation from roots to leaves of two eggplant species (Solanum melongena and Solanum torvum) under relatively low Cd concentrations were investigated using stable (108)Cd isotope through a number of hydroponic experiments. The uptake and translocation of (108)Cd was compared with those of (70)Zn and (15)N. The results showed more (108)Cd was loaded to the vascular channels and translocated upward to the leaves in S. melongena than in S. torvum, while the (108)Cd concentrations were significantly lower in the roots of S. melongena than in S. torvum. When the phloem and xylem were wounded by grafting treatments, the foliar (108)Cd concentrations were decreased by more than 66% regardless of the rootstock species, whereas the uptake of (108)Cd in the root was not inhibited by grafting. Similar grafting effects were observed for (70)Zn. Hence, wounding phloem and xylem by grafting disturbed the upward transport of (108)Cd and (70)Zn to the eggplant leaves. Similarly, interruption of the phloem by the girdling treatment reduced the concentrations of (108)Cd in the leaves of S. melongena by approximately 51%, though the uptake of (108)Cd by roots was not reduced by the interruption of phloem. In contrast, neither (70)Zn concentrations nor stable N isotope ratio (δ(15)N) values in the roots and leaves of S. melongena were significantly influenced by the interruption of phloem. In conclusion, the phloem played a dominant role in the long-distance transport of Cd from the root to the leaf of S. melongena, whereas the xylem was the main channel for the translocation of Zn and N.
authors.affiliation: Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Qin
authors.affiliation: College of Chemistry and Life Science, Shenyang Normal University, Shenyang, 110034, China.
authors.forename: Xuemei
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Biosystems Engineering and Soil Science, Institute for a Secure and Sustainable Environment, The University of Tennessee, Knoxville, TN, 37996, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhuang
authors.affiliation: Department of Soil Quality, Wageningen University, PO Box 47, 6700AA, Wageningen, The Netherlands.
authors.forename: Liping
authors.initials: L
authors.lastname: Weng
authors.affiliation: Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China.
authors.forename: Wan
authors.initials: W
authors.lastname: Liu
authors.affiliation: Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China. pdtai13@163.com.
authors.forename: Peidong
authors.initials: P
authors.lastname: Tai
mesh_terms: D001692:Biological Transport; D002104:Cadmium / Q000493:pharmacokinetics*; D052585:Phloem / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D012989:Soil Pollutants / Q000493:pharmacokinetics*; D032323:Solanum melongena / Q000378:metabolism*; D052584:Xylem / Q000378:metabolism
chemical_list: D012989:Soil Pollutants; D002104:Cadmium
keywords: Eggplant (Solanum melongena); Girdling; Grafting; Heavy metals; Phloem; Transport