Cadmium effect on hydrogen peroxide, gluthatione and phytochelatins levels in potato tuber

Short-term treatment of potato tuber (Solanum tuberosum L.) discs with CdCl2 (1 mM) induced an oxidative stress, manifested by higher levels of H2O2, and activated the synthesis of phytochclatins ((gamma-Glu-Cys)(n)-Gly): PC2, PC3 and PC4. If in the tissues with a lower GSH level, the oxidative stress was induced by treatment with 3-aminotriazol (AT), or with AT and H2O2 the elevation of H2O2 and GSH levels and then some accumulation of thiols, includiug PC2, PC3 and PC4, were observed. However. this increase of PC concentration was considerably lower when compared with the effects brought about by Cd+2 treatment. If such a procedure of evoking subsequent moderate oxidative stress in tissues preceded Cd-treatment, a marked limitation of PC synthesis was observed. The presented results support the role of H2O2 as the second messenger in activating GSH synthesis and thus suggest a possibility of redox type regulation mechanism of PCs synthesis.