Investigation of the palliative role of tauri̇ne on against cadmium damages on maize (Zea mays Hido) seedlings

In this study, it was investigated whether taurine (T) had mitigating effects on the damage-inducing effect of cadmium (Cd) on maize seedlings. For this purpose, 100 µM Cd was applied to maize seedlings grown for 10 days in the hydroponic system containing Hogland, and 1 mM T and 2 mM T applications were made in addition to Cd in other experimental groups. Four days after the applications, the seedlings were harvested and analyzed. While root and shoot lengths decreased in plants under Cd stress compared to control, T applications significantly increased root and shoot lengths compared to Cd application. Cadmium application caused a significant increase in root dry weight compared to control. While Cd stress caused a significant decrease in soluble protein content in plants, T application showed a significant increase in protein content compared to the Cd group. Alone and combined applications of Cd and T also led to noticeable differences in protein profile. Cadmium stress caused a decrease in chlorophyll a, b, carotenoid, and total chlorophyll content in corn seedlings, while taurine caused significant increases in these parameters. Compared to control, Cd stress caused a significant decrease in antioxidant enzyme activities of SOD, CAT, APX, and GR except for POD as well as glutathione and ascorbate content in maize seedlings. Taurine application provided an increase in the activity of antioxidant enzymes and the content of these antioxidant substances compared to Cd application alone. While Cd application caused an increase in H2O2 and O2•- content of reactive oxygen species, taurine application significantly decreased the content of these reactive substances. While lipid peroxidation levels were increased significantly with Cd application, it was determined that these increases could be prevented by the addition of taurine. It was also determined that taurine application also affected Cd uptake and/or transport. When all these results are evaluated together, it has been revealed that taurine has a mitigating effect against Cd-induced damage in maize seedlings. It can be said that taurine provides this effect by regulating Cd uptake and/or transport within the plant, as well as influencing antioxidant metabolism.