Effects of polyamines and polyamine biosynthetic inhibitors on mitotic activity of Allium cepa root tips

Abstract

The genotoxic and cytotoxic effects of exogenous polyamines (PAs), putrescine ( Put), spermidine (Spd), spermine (Spm) and PA biosynthetic inhibitors, alpha-difluoromethylornithine ( DFMO), cyclohexilamine (CHA), methylglioxal bis-(guanylhydrazone) ( MGBG) were investigated in the root meristems of Allium cepa L. The reduction of mitotic index and the induction of chromosomal aberrations such as bridges, stickiness, c-mitotic anaphases, micronuclei, endoredupliction by PAs and PA biosynthetic inhibitors were observed and these were used as evidence of genotoxicity and cytotoxicity.