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-Cy s)(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 (A T), 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 wh en 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 observ ed. The presented results support the role of H2O2 as the second messe nger in activating GSH synthesis and thus suggest a possibility of red ox type regulation mechanism of PCs synthesis.