Genetic Engineering for Osmotic Stress Tolerance in Plants – Role of Proline

As sessile organisms, plants have developed adaptive strategies to cope with environmental stress by expressing specific genes and synthesizing a variety of proteins or compounds, including compatible solutes like proline, glycinebetaine, trehalose and sugars. Among these, proline is the most widely found osmolyte in stressed plants. Proline participates not only in osmotic adjustment but also as a response to environmental stresses like low temperature, nutrient deficiency, exposure to heavy metals and high acidity. Therefore, a wise strategy of introducing genes into plants which lead to enhanced biosynthesis of proline was adopted. This strategy has resulted in transgenic plants showing increased osmotic stress tolerance.