Cadmium elevates level of protein amino acids and

Authors: Kavita Shah R S Dubey

Publish Date: 1998/06/01

Volume: 20, Issue: 2, Pages: 189-196

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Abstract

When seeds of two rice cvs Ratna and Jaya were germinated under increasing levels of cadmium nitrate 0 100 and 500 µM in the medium a marked decrease in germination percentage was observed with Cd treatments as compared to controls There was more absorbed Cd in embryo axes than in endosperms More uptake resulted with increasing Cd levels in the growth medium in embryo axes In both rice cultivars during a germination period of 0 – 120 h an increased level of protein as well as free amino acids was noted in Cd treatments Protease activity in general decreased in both embryo axes as well as endosperms due to Cd treatment In vitro studies showed an enhancement in protease activity in Cd treatments at low Cd levels 50–100 µM whereas concentrations above this caused inhibition in enzyme activity Under 500 µM Cd treatments in vivo there was about 30 to 50 percent decline in leucine aminopeptidase LAP activity in endosperms however carboxypeptidase activity showed a marked increase in endosperms beyond 24 h under Cd treatments In embryo axes of germinating seeds there was always a decline in peptidase activities under the influence of cadmium The leucine amino peptidase and protease activity were always greater in embryo axes in cv Ratna than cv Jaya However the carboxypeptidase activity was higher in Jaya when compared to Ratna in endosperms under Cd treatments The results suggest possible suppression of protease and peptidase activities due to Cd treatments in germinating rice seeds leading to altered levels of protein and amino acids

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