MOLECULAR ANALYSIS OF POLYAMINE BIOSYNTHESIS IN HIGHER-PLANTS

The polyamines are low molecular weight, polycationic, nitrogenous com pounds, and normal constituents of prokaryotic and eukaryotic cells, T hey have been implicated in a wide range of metabolic processes in pla nts ranging from cell division and organogenesis to protection against stress, Genes for several key biosynthetic enzymes like arginine deca rboxylase, ornithine decarboxylase and S-adenosyl methionine decarboxy lase have been cloned from different plant species, They have been fou nd to be regulated by developmental cues and also by different kinds o f stress, Both over expressed and antisense transgenic approaches of p olyamine biosynthetic genes have further supported that these compound s are essential for normal plant growth and development, Recent genera tion of polyamine biosynthetic mutants of Arabidopsis also suggests th e importance of polyamines as cellular metabolites, The current develo pment in the knowledge of polyamine biosynthesis, particularly molecul ar genetic analysis, has been discussed in this review that will help to open up new avenues of investigation for the researchers.