title: How phytohormone IAA and chelator EDTA affect lead uptake by Zn/Cd hyperaccumulator Picris divaricata.
abstract: In this paper, the effects of indole-3-acetic acid (IAA) and/or ethylenediaminetetraacetic acid (EDTA) on lead uptake by a Zn/Cd hyperaccumulator Picris divaricata were studied. P. divaricata responded to Pb by better root system and increased biomass in presence of phytohormone IAA, which was able to reduce the inhibiting effects of Pb on transpiration without reducing the uptake of Pb The application of 100 microM IAA increased plant transpiration rate by about 20% and Pb concentration in leaves by about 37.3% as compared to treatment exposed to Pb alone. The enhanced phytoextraction efficiency could be attributed to the mechanisms played by IAA through alleviating Pb toxicity, creating better root system and plant biomass, promoting a higher transpiration rate as well as regulating the level of nutrient elements. On the contrary, inefficiency of phytoextraction was found with EDTA or the combination of IAA and EDTA probably because most Pb was in the form of Pb-EDTA complex which blocked the uptake by P. divaricata. The present study demonstrated that IAA was able to enhance the phytoextraction of Pb by Zn/Cd hyperaccumulator P. divaricata, providing a feasible method for the phytoremediation of polymetallic contaminated soils.
authors.affiliation: School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, People's Republic of China.
authors.forename: Rui-Jun
authors.initials: RJ
authors.lastname: Du
authors.forename: Er-Kai
authors.initials: EK
authors.lastname: He
authors.forename: Ye-Tao
authors.initials: YT
authors.lastname: Tang
authors.forename: Peng-Jie
authors.initials: PJ
authors.lastname: Hu
authors.forename: Rong-Rong
authors.initials: RR
authors.lastname: Ying
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Morel
authors.forename: Rong-Liang
authors.initials: RL
authors.lastname: Qiu
mesh_terms: D019659:Asteraceae / Q000187:drug effects / Q000378:metabolism*; D018533:Biomass; D002614:Chelating Agents / Q000494:pharmacology*; D004492:Edetic Acid / Q000494:pharmacology*; D004787:Environmental Pollution; D007210:Indoleacetic Acids / Q000494:pharmacology*; D007854:Lead / Q000032:analysis / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000494:pharmacology*; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D018526:Plant Transpiration / Q000187:drug effects; D012987:Soil / Q000032:analysis; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism
chemical_list: D002614:Chelating Agents; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D012987:Soil; D012989:Soil Pollutants; D007854:Lead; C030737:indoleacetic acid; D004492:Edetic Acid