THE COMPOSITION OF METALS BOUND TO CLASS-III METALLOTHIONEIN (PHYTOCHELATIN AND ITS DESGLYCYL PEPTIDE) INDUCED BY VARIOUS METALS IN ROOT CULTURES OF RUBIA-TINCTORUM

The induction of phytochelatins (PCs) and their desglycyl peptides (bo th are referred to as class III metallothionein [CIIIMT]) by exposure to various metals (Ag+, As3+, AS(5+), Cd2+, CU2+, Ga3+, Hg2+, In3+, Ni 2+, Pb2+, Pd2+, Se4+, and Zn2+) and the metal composition in the CIIIM Ts were investigated in root cultures of Rubia tinctorum L. All of the se metal species induced PCs to various degrees when analyzed by the p ostcolumn derivatization highperformance liquid chromatography method. The desglycyl peptides of PCs often were also present. However, only Ag, Cd, and Cu were bound to the CIIIMTs that they induced when analyz ed by the high-performance liquid chromatography-inductively coupled p lasma-atomic emission spectrometry method. Cu was also bound to the CI IIMTs induced by Ag+, As3+, and Cd2+. After Ag+ exposure, an Fe peak t hat may be of Fe-CIIIMT was also observed. However, most of the metal species studied were not bound to the CIIIMTs that they induced.