THE SIGNIFICANCE OF CHLOROPHYLLS AND CAROTENOIDS IN ENHANCING SEED TOLERANCE TO ABIOTIC STRESS

the degradation of chlorophylls during seed ripening, residual levels are detectable in mature seeds, affecting their stress tolerance. Carotenoids, predominantly lutein and β-carotene, accumulate in seeds under accelerated aging conditions and high-temperature germination, influencing stress response. The ratio of carotenoid to chlorophyll content (Car/Chl) emerges as a potential indicator of seed stress tolerance, with higher ratios correlating with enhanced resilience to stressors. Objective: This study aims to elucidate the significance of chlorophylls and carotenoids in enhancing seed tolerance to abiotic stressors by investigating their roles and interactions within seeds under stress conditions. Methods: Physiologically mature seeds containing residual chlorophylls were subjected to stress treatments, and carotenoid levels were assessed during seed aging and germination experiments. The Car/Chl ratio was calculated to evaluate its relationship with seed stress tolerance. Results: Seeds with elevated Car/Chl ratios exhibited higher tolerance to stress treatments, suggesting a protective role of carotenoids against oxidative stress induced by chlorophylls under abiotic stress conditions. Carotenoid accumulation during aging and germination further underscored their role in stress response, influencing seed resilience. Conclusion: although residual in mature seeds, chlorophylls contribute to oxidative stress under abiotic stressors. Conversely, carotenoids act as antioxidants, mitigating stress-induced damage and enhancing seed tolerance. The Car/Chl ratio is valuable for assessing seed stress resilience, providing insights into seed physiology under adverse environmental conditions.