Morphophysiological and biochemical responses of Zinnia elegans L. seedlings to exogenous proline following chilling exposure.

Exogenous proline at 10 mM enhances recovery and stress tolerance in Zinnia elegans seedlings exposed to chilling temperatures.

• Why it matters: Low-temperature stress during early growth stages hampers plant development, threatening ornamental species like Zinnia elegans, and effective mitigation strategies are needed.
• What they did: A factorial experiment applied foliar proline (0, 5, and 10 mM) to seedlings subjected to 3°C chilling for five days, assessing morphological, physiological, and biochemical responses.
• The result: Proline treatment improved growth, water content, photosynthesis, and antioxidant activity, especially at 10 mM, enabling better post-chilling recovery and stress resilience.