Modulation of Free Amino Acid Metabolism in Carrots Under Postharvest Wounding and Water Stress

Amino acids play a fundamental role in plant metabolism, acting as building blocks for proteins and participating in stress responses as osmolytes and signaling molecules. Carrots ( Daucus carota ) are widely consumed root vegetables rich in bioactive compounds, including amino acids, which contribute to their nutritional value. Postharvest conditions, such as wounding and water stress, can alter metabolic pathways, affecting amino acid composition. While previous studies have shown that wounding stress increases phenolic compound accumulation in carrots, little is known about the effects of wounding and water stress on free amino acid ( f ‐AA) metabolism. This study investigates the impact of these stressors, individually and in combination, on the amino acid profile of carrots. Our results indicate that wounding stress significantly decreases most f ‐AA levels, suggesting a disruption in biosynthesis. In contrast, water stress led to a time‐dependent increase in several amino acids, including proline, alanine, and leucine, with a total f ‐AA increase of up to 40% after 48 h. When carrots were subjected to both wounding and water stress (double stress [DS]), the negative effects of wounding stress on amino acid content were partially mitigated. Notably, arginine showed the most substantial recovery under DS conditions, while lysine remained unaffected. These findings suggest that postharvest stress conditions can significantly modulate amino acid metabolism in carrots. While wounding stress negatively impacts amino acid levels, water stress enhances their accumulation. Understanding these metabolic responses could provide insights for improving postharvest strategies to enhance carrot nutritional quality.