ABSTRACT
Proline is a proteinogenic amino acid with conformational rigidity and is a pre-requisite for primary metabolism. Proline has been extensively reported for its potential role in osmotic adjustment in plant cells. More the stress regulatory properties of proline have been affirmed by a plethora of researchers. Proline metabolism includes its synthesis and degradation. The synthesis takes place by the glutamate and ornithine pathways. Proline anabolism is induced and its catabolism is suppressed during dehydration, but rehydration stimulates the inverse regulation. Under abiotic stress conditions, the plant synthesizes enormous amounts of various compatible solutes or osmoprotectants including proline. Proline has been found to play a regulatory function in the growth and development of plants by acting as a signaling molecule. Proline is also known to protect photosystem II by protecting the thylakoid membranes from oxidative stress. There is little knowledge about the post-translational modification of enzymes of the proline metabolic pathway.
