BIOREMEDIATION - Part II 

Minerva Biotecnologica 2001 June;13(2):93-5

Copyright © 2001 EDIZIONI MINERVA MEDICA

language: English

Toxic metals accumulation and total soluble phenolics in sunflower and tobacco plants

Ruso J. ¹, Zapata J. ², Hernandez M. ³, Ojeda M. A. ⁴, Benlloch M. ⁴, Prats-Perez E. ¹, ena M. ¹, Lopez-Valbuena R. ¹, Jorrin J. ¹

¹ Department of Biochemistry, Molecular Biology, ETSIAM, University of Cordoba, Spain; ² Universidad de Concepción, Chile; ³ Centro de Bioplantas, Instituto Superior de Agrícola, Ciego de Avila, Cuba; ⁴ Department of Agronomy, ETSIAM, University of Córdoba, Spain

Background. Toxic met­al con­tam­i­na­tion is now­a­days one of the ­most seri­ous prob­lems ­with ­great inci­dence on ­human ­health and the envi­ron­ment. As a con­se­quence of min­ing and oth­er indus­tri­al activ­ities, munic­i­pal ­wastes and sew­age, tox­ic met­als ­like Cu, Zn, Pb, Cd, Ni, Hg, and As are ­being accu­mu­lat­ed at tox­ic lev­els in ­soil and ­water. Phytoremediation by ­using ­plants as met­al accu­mu­la­tors is one of the ­most prom­is­ing strat­e­gies to ­remove tox­ic met­als ­from ­soils. Evaluation of dif­fer­ent ­crops and ­wild spe­cies as met­al accu­mu­la­tors is ­part of a mul­ti­dis­ci­pli­nary ­approach to mul­ti­com­po­nent met­al con­tam­i­na­tion ­caused by the Aznalcollar (Southern Spain) tox­ic ­spill in 1998.
Methods. Two ­lines of cul­ti­vat­ed sun­flow­er and tobac­co ­have ­been eval­u­at­ed for ­growth, tox­ic­ity symp­toms and met­als accu­mu­la­tion in pot and hydro­pon­ic ­systems. The con­tent in ­total sol­u­ble phe­nol­ics com­pound, as gen­er­al ­plant ­defence ­response, and the ­effect of tox­ic met­als has ­been stud­ied in ­order to eval­u­ate cor­re­la­tion­ships ­between ­both param­e­ters.
Results. Tobacco has ­shown ­less tol­er­ance to ­heavy met­als ­than sun­flow­er. Metals accu­mu­lat­ed in ­roots, and to a ­much less­er ­extent in the aer­i­al ­part, ­depend on the spe­cies, ­line and experi­men­tal ­system ­used. By ­using sun­flow­er and tobac­co as experi­men­tal mod­els a ­good cor­re­la­tion has ­been ­observed ­between the ­induced syn­the­sis of phe­nol­ics, main­ly in ­root tis­sue, and tol­er­ance to and accu­mu­la­tion of ­heavy met­als.
Conclusions. Although sun­flow­er is not a hyper­ac­cu­mu­la­tor ­plant, due to its ­fast ­growth, ­high bio­mass and ­large ­roots, ­this ­crop can be pro­posed for inclu­sion in phy­tor­e­me­di­a­tion pro­to­cols ­using ­lines select­ed for ­their con­stit­u­tive and ­induced phe­nol­ics con­tent.