TOXICITY ASSESSMENT OF ARSENITE AND ITS RELATIONSHIP WITH ARSENIC POLLUTED AREA OF TARNIȚA: THE PROTECTIVE EFFECT OF GLUTATHIONE

Tailings deposits in Tarnița, Suceava County affect the soils around. These large sterile dumps are highly contaminated with arsenic and heavy metals. The effect of various concentrations of arsenite and arsenate on wheat seeds and seedling growth within several germination experiments was investigated in order to assess potential individual toxicity of arsenic released from the sterile dumps. Samples of spring wheat (Triticum aestivum L.) seeds were used to investigate the effect of arsenic at seed level and its influence on the resulting plantlets. The effect of glutathione on sodium arsenite toxicity in wheat during the germination process was also studied. Arsenite (NaH2AsO3) concentrations ranged from 0.25 mM to 5 mM, while the concentrations of arsenate (NaH2AsO4) and glutathione (GSH) solutions were 1 mM and 10 mM, respectively. Germination rate of wheat seeds decreased significantly with increasing arsenite concentrations; it decreased from 100% (control) to only 24%, when a 5 mM arsenite concentration was reached. A similar trend was observed for total shoot heights and masses of wheat seedlings by increasing arsenite concentrations. Interestingly, GSH alone slightly decreased the average heights and mass of shoots as compared with the control carried out with distilled water (Control: 9.04 cm and 2.34 g; GSH: 7.18 cm and 1.78 g). However, GSH completely recovered the germination of 0.25 mM arsenite* Gabi Drochioiu, e-mail: gabidr@uaic.ro 96 A. Butnariu et al. intoxicated seeds (no GSH: 4.39 cm and 1.29 g; GSH: 7.24 cm and 1.81 g). Moreover, a more concentrated arsenite solution (0.826 mM) almost completely inhibited the wheat germination (0.32 g of shoots with an average height of 0.99 cm), while GSH partially restored both germination parameters (0.84 g and 2.45 cm, respectively). Briefly, wheat germination approaches may be authentic and inexpensive toxicity screening methods of arsenic in the environment.