?Removal of copper from aqueous solutions by rhizofiltration using genetically modified hairy roots expressing a bacterial Cu-binding protein?.

PATRICIA PÉREZ-PALACIOS; ELIZABETH AGOSTINI; SABRINA IBAÑEZ; MELINA TALANO; RODRÍGUEZ-LLORENTE IGNACIO; CAVIEDES MIGUEL A.; ELOÍSA PAJUELO- DOMÍNGUEZ

ENVIRONMENTAL TECHNOLOGY

TAYLOR & FRANCIS LTD

Lugar: Londres; Año: 2017 vol. 38 p. 2877 - 2888

0959-3330

The aim of this work was to develop a biotechnological tool to hyperaccumulate high copper (Cu)concentrations from wastewaters. Transgenic tobacco hairy roots were obtained by expressing,either the wild-type version of the gene copC from Pseudomonas fluorescens in the cytoplasm ofplant cells (CuHR), or a modified version targeted to the vacuole (CuHR-V). Control hairy rootstransformed with the empty vector (HR) were also generated. The roots were incubated in thepresence of solutions containing Cu (from 1 to 50 mM). At 5 mM external copper, transgenichairy roots accumulated twice the amount of copper accumulated by control hairy roots.However, at 50 mM Cu, accumulation in both transgenic and control roots reached similarvalues. Maximum Cu accumulation achieved by transgenic hairy roots was 45,000 μg g−1 at50 mM external Cu. Despite the high Cu accumulation, transgenic hairy roots, particularly CuHRV,showed less toxicity symptoms, in correlation with lower activity of several antioxidantenzymes and lower malondialdehyde (MDA) levels. Moreover, CuHR-V roots displayed low valuesof the oxidative stress index (OSI) ? a global parameter proposed for oxidative stress ? indicatingthat targeting CopC to the vacuole could alleviate the oxidative stress caused by Cu. Our resultssuggest that expressing copC in transgenic hairy roots is a suitable strategy to obtainCu-hyperaccumulator hairy roots with less toxicity stress symptoms.