title: Accumulation of copper by roots, hypocotyls, cotyledons and leaves of sunflower (Helianthus annuus L.).
abstract: The effects of different concentrations of copper sulfate on the growth of and the accumulation of Cu2+ by root, hypocotyl, cotyledon and leaf growth of sunflower (Helianthus annuus L.) were examined in this study. The concentrations of copper sulfate (CuSO4 x 5H2O) used were in the range from 10(-5) to 10(-3) M. Seedlings exposed to 10(-5) M Cu2+ solution exhibited a 33% increase in growth (P < 0.005) when compared with the root length of the control. The seedlings treated with 10(-3) M Cu2+ were significantly inhibited in shoot growth (P < 0.005). The Cu2+ content in roots, hypocotyls, cotyledons and leaves increased with increasing solution Cu2+ concentration. The roots of plants exposed to 10(-3) M Cu2+ accumulated a large amount of Cu (1070 microgram/g DW), and the Cu2+ level was approximately 25 fold higher than that of control. The Cu2+ contents in sunflower roots treated with 10(-4) and 10(-5) M Cu2+ were about 3.3 and 2.6 fold higher than the control, respectively. Also, the Cu2- level of the roots exposed to 10(-3) M Cu2+ was approximately 7.7 and 9.8 fold respectively, in comparison with the roots of plants grown in 10(-4) and 10(-5) M Cu2+. At 10(-3) M Cu2+, the Cu accumulated mainly in the roots (about 73%), and small amounts of Cu2+ (27%) were translocated to the hypocotyls, cotyledons and leaves. The Cu2+ concentration in the roots was less than that of the above parts of seedlings in treated groups with 10(-5) - 10(-4) M Cu2+. H. annuus has potential ability to accumulate Cu without being overly sensitive to Cu toxicity.
authors.affiliation: Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing 100093, China.
authors.forename: Jinxing
authors.initials: J
authors.lastname: Lin
authors.forename: Wusheng
authors.initials: W
authors.lastname: Jiang
authors.forename: Donghua C
authors.initials: DC
authors.lastname: Liu
mesh_terms: D000931:Antidotes / Q000737:chemistry; D003300:Copper / Q000493:pharmacokinetics* / Q000633:toxicity; D019327:Copper Sulfate / Q000737:chemistry; D006368:Helianthus / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry*; D018517:Plant Roots / Q000737:chemistry*; D012989:Soil Pollutants / Q000493:pharmacokinetics* / Q000633:toxicity; D014018:Tissue Distribution
chemical_list: D000931:Antidotes; D012989:Soil Pollutants; D003300:Copper; D019327:Copper Sulfate