ABSTRACT
Proline is unique among the 20 protein-forming amino acids in that the amine nitrogen is bound to several alkyl groups. It is widely recognized as playing a peculiar role in the folding/unfolding transitions of the globular protein. Poverty or near absence of proline in the primary protein sequence may govern the level of disorder in the protein structure Saibi et al. Proline was considered and will remain an important platform, which is implicated in various physiological phenomena, in the microorganism, animal, and vegetal kingdoms Bita and Gerats. The improvement of drought and/or salt tolerance of crop plants via engineering proline metabolism is a plausible opportunity that should be explored more extensively. Eventually, the fact that proline can act as a signaling effector and influence defense pathways and regulate metabolic and developmental processes offers additional opportunities for plant improvement. Proline catabolism in the mitochondria is connected to oxidative respiration and administers energy to resumed growth after stress.
