Physiological responses and phytoextraction potential of Canna indica L. under Zn(II) and Cu(II) stress

MATIAS GONZALEZ; MARCELA RUSCITTI; JOSEFINA PLAZA CAZÓN

Congreso; XXXIII Argentinian Meeting on plant phisiology; 2021

In the last years, soil heavy metal contamination has become one of the most serious environmental problems due to being not biodegradable and having high persistence in the environment. Phytoremediation is a low-cost technique for the treatment of large areas with medium or low concentrations of heavy metals but its success depends, among other variables, on proper species selection. A pot experiment was carried out to determine the usefulness of Canna indica as a Zn(II) and Cu(II) phytoremediator species. The plants were grown until reaching adequate biomass for the application of three increasing Zn(II) (1000, 2000 and 3000 mg.kg-1) and Cu(II) (500, 1000 and 1500 mg.kg-1) solutions. Seven days later, dry weight, relative membrane conductivity, chlorophyll, carotene, malondialdehyde, soluble proteins and shoot Zn(II) and Cu(II) contents were measured. Zn(II) treatment caused a decline in the dry weight, chlorophyll and carotene contents, whereas the relative conductivity, malondialdehyde and soluble proteins content, all in the aerial part, showed the opposite pattern. Cu(II) applications caused a decrease in the dry weight, chlorophyll, carotene and soluble protein content, while the opposite pattern was observed for relative conductivity and malondialdehyde content. Shoot heavy metal content reached values approximately 70 (1580 mg.kg-1) and 12 times higher (145 mg.kg-1) for Zn(II) and Cu(II) than the control respectively. Although some physiological functions were altered, the plants could grow without major alterations. Our results suggest that Canna indica can be used for the phytoremediation of polluted soils with moderate concentrations of Zn(II) and Cu(II).