ORIGINAL ARTICLE Generation of transformed roots of Scirpus americanus Pers. and study of their potential to remove Pb 2+ and Cr 3+ Elvia Francisca Alfaro-Saldan ˜a 1 • Eugenio Pe ´rez-Molphe-Balch 2 • Marı ´a del Socorro Santos-Dı ´az 1 Received: 28 January 2016 / Accepted: 11 June 2016 / Published online: 24 June 2016 Ó Springer Science+Business Media Dordrecht 2016 Abstract In vitro root cultures of Scirpus americanus are capable to remove heavy metals. To improve metal uptake, this work focused on the production of transformed roots with the strain A4 of Agrobacterium rhizogenes containing the agropine-type plasmid pRiA4 and the binary vector pESC4. Materials used as explants included in vitro root cultures, seedlings grown under hydroponic conditions, and in vitro seedlings. Infection of in vitro root cultures failed to produce hairy roots, while the infection of greenhouse and in vitro seedlings induced 84 and 67 % GUS-positive hairy roots, respectively. From 31 clones obtained, clones T11, T12 and T14 expressed the genes nptII and rol B. As T12 exhibited a faster growth, it was selected for metal- uptake experiments. Clone T12 grown in the presence of metals removed 3.8 and 1.2 times more Pb and Cr, respectively, than non-transformed roots, suggesting that this clone displays more efficient tolerance mechanisms to Pb and Cr. Metal absorption was 4–6 fold higher than adsorption. Transgenic plants were regenerated from in vitro root cultures of clone T12. The use of hairy roots and transformed plants of S. americanus could provide an alternative strategy for the remediation of water contami- nated with heavy metals. Keywords Agrobacterium rhizogenes Á Chromium Á Lead Á Phytoremediation Á Scirpus americanus Introduction Heavy metals are hazardous water and soil pollutants. Metal toxicity results from the binding of ions to functional groups in proteins, nucleic acids or lipids, leading to the inhibition of their activity or the disruption of their struc- ture; also, they replace essential metal ions from the active center of enzymes, hence leading to deficiency effects (Hall 2002). Excess heavy metals may produce harmful reactive oxygen species (ROS), which react with macro- molecules and affect their function; inhibit plant growth, induce chlorosis, tip wilting and lesions in roots, among other effects. Particularly, Pb and Cd interact with mem- brane lipids and proteins, antioxidant enzymes, and ele- ments of the electron-transport chain, disrupting their functioning (Yadav 2010). Heavy-metal stress has also been shown to activate the expression of various genes, leading to alterations in pro- tein content. High Pb levels have been reported to result in lower protein content in Brassica juncea, likely due to the degradation by proteases, whose levels increase under stress conditions (Palma et al. 2002). Traditional methods to reduce metal contamination in soil and water include extraction, immobilization, isola- tion, and toxicity reduction (Mulligan et al. 2001). Electronic supplementary material The online version of this article (doi:10.1007/s11240-016-1025-2) contains supplementary material, which is available to authorized users. & Marı ´a del Socorro Santos-Dı ´az ssantos@uaslp.mx Elvia Francisca Alfaro-Saldan ˜a ealfaro8484@yahoo.com.mx Eugenio Pe ´rez-Molphe-Balch eperezmb@correo.uaa.mx 1 Facultad de Ciencias Quı ´micas, UASLP, Manuel Nava 6, CP 78210 San Luis Potosı ´, Mexico 2 Departamento de Quı ´mica, Centro de Ciencias Ba ´sicas, UAA, Av. Universidad 940, CP 20131 Aguascalientes, Mexico 123 Plant Cell Tiss Organ Cult (2016) 127:15–24 DOI 10.1007/s11240-016-1025-2