Effect of Cadmium on Glutathione Reductase of wheat plants

FERNÁNDEZ ALVAREZ, ANA JULIA; TOMARO, MARÍA L

Villa Carlos Paz

Congreso; XXXVII Reunión Anual de La Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2002

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Cadmium has been involved in oxidative stress generation, but the molecular mechanisms of its toxicity are not known with any certainty. Glutathione reductase (GR) is necessary for maintaining high the GSH/GSSG ratio in cells, playing a very important role in protection of plants against oxidative stress. Therefore, the objective of this work was to study the behavior of activity and isozymes pattern of GR in wheat leaves and roots subjected to 100 uM CdCl2, at 7, 14 and 21 days after treatment. Protein content was not affected in leaves along the experimental time, while roots protein levels increased at 7 and 14 days, but decreased at day 21. The activity and isozymes profile of GR remained unaltered in leaves at the three times assayed. However, in roots, an increase of GR activity was observed 7 and 14 days after cadmium treatment (180& and 100% over the controls, respectively), while a 40 % decrease was found at day 21. Accordingly, a difference in the isozymes profile was detected. In specifically stained native PAGE, two of th three GR isozymes present in controls were absent at 7 and 14 days. The unique isozyme observed in Cd-treated roots was markedly increased compared to controls. This effect was not detected at day 21, where isozymes pattern was similar to control plants. These results suggest a response of wheat roots to cadmium intoxication conditions.