Application of capillary electrophoresis on the characterization of cadmium‐induced polypeptides in roots of pea plants

Abstract

Capillary electrophoresis (CE) has revealed as a powerful technique for a rapid and effective evaluation of the synthesis of polypeptides induced by cadmium (Cd) in root tissues of Cd‐resistant pea plant. CE was performed on root extracts in capillary gel electrophoresis (CGE) using 3% PEG 2November 1998 in Tris‐Tricine buffer as a dynamic sieving polymer solution and in free solution (FSCE) with 0.1M Tris‐Tricine at pH 8.3 as running buffer. By comparison with control, CGE electropherograms of root extracts of Cd‐resistantpea showed a new peak, characteristic of newly synthesized polypeptidic fraction with apparent molecular weight of 10 kDa. In order to get more information, we characterized further the new synthesized polypeptidic fraction as charge to size ratios. Results obtained by FSCE in free solutions showed that polypeptidic fraction split into several components with different charge to size ratios, very close to that of glutathione, the starting molecule for the biosynthesis of phytochelatins. In addition, results suggested a co‐occurrence of MT‐like proteins at low molecular weight and phytochelatins.