Overexpression of a basic peroxidase in transgenic tomato ( Lycopersicon esculentum Mill. cv. Pera) hairy roots increases phytoremediation of phenol

• Published in: Plant science (Limerick) Vol. 169; no. 6; pp. 1102 - 1111
• Main Authors: Wevar Oller, Ana L., Agostini, Elizabeth, Talano, Melina A., Capozucca, Cristian, Milrad, Silvia R., Tigier, Horacio A., Medina, María I.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 01.12.2005; Elsevier Science
• Subjects: Agronomy. Soil science and plant productions; Basic peroxidase; Biological and medical sciences; enzyme activity; Fundamental and applied biological sciences. Psychology; gene overexpression; Genetic engineering applications; Genetics and breeding of economic plants; isozymes; molecular sequence data; Northern blotting; nucleotide sequences; Overexpression; peroxidase; Phenol; phenols; Phytoremediation; plant biochemistry; Plant breeding: fundamental aspects and methodology; polymerase chain reaction; root hairs; Solanum lycopersicum var. lycopersicum; tissue culture; Tomato; tomatoes; Transgenic hairy roots; transgenic plants; Phenol; Basic peroxidase; Overexpression; Tomato; Transgenic hairy roots; Phytoremediation; Root; Enzyme; Tissue culture; Cell wall; Peroxidases; Gene; Dicotyledones; Angiospermae; Lycopersicon esculentum; Phenols; Spermatophyta; Genetic engineering; Peroxidase; Oxidoreductases; Solanaceae
• ISSN: 0168-9452; 1873-2259
• DOI: 10.1016/j.plantsci.2005.07.007

In recent years, genetic engineering and tissue culture techniques have produced significant biotechnological advances in phytoremediation. Numerous peroxidases (E.C. 1.11.1.7) have been implicated in the phytoremediation of phenol, a common and highly toxic contaminant present in industrial wastewaters. To explore the possibility of enhancing phenol removal and to find out if tpx1, a basic (p I 9.6) peroxidase from tomato, is involved in phenol removal, we established transgenic tomato hairy root clones which overexpress tpx1 gene, following an unusual procedure: successive transformation with Agrobacterium tumefaciens and Agrobacterium rhizogenes. The overexpression of tpx1 correlated with higher in vivo and in vitro peroxidase activity in crude extracts (CE) of transgenic hairy root clones than in those of the wild type culture. Furthermore, peroxidase zymograms of transgenic clones showed higher activity of a band with p I 9.6 in the fraction of ionically bound to cell wall proteins. The transgenic clones with the highest peroxidase activity (clones 8 and 9) were selected and tested for phenol removal from aqueous solutions. Removal efficiency of the transgenic clone 8 was significantly higher than the wild type hairy roots. The data presented here provide evidence of the utility of successive transformation for obtaining stable transgenic hairy roots and demonstrate that engineered hairy root cultures overexpressing tpx1 peroxidase enhance phenol removal and could be useful tools in phytoremediation process.