The up-regulation of proline synthesis in the meristematic tissues of wheat seedlings upon short-term exposure to osmotic stress.

An increase in the cellular concentration of free proline is a common response of many plants to various types of environmental stress. In this study, we monitored the accumulation of proline and the activities of Δ-pyrroline-5-carboxylate synthetase (P5CS) and Δ-pyrroline-5-carboxylate reductase (P5CR), the key enzymes of proline biosynthesis, in different parts of 4-day-old seedlings of wheat (Triticum aestivum L. cv.