Comparative Metabolomics of Sesame Cultivars in Response to Seed Deterioration Stress Treated With Cis-Cinnamic Acid

Seed deterioration is considered an abiotic stress that has significant destructive effects on seed germination and seedling establishment in oilseed crops. In this study, the responses to seed deterioration in two sesame cultivars were evaluated based on seed and seedling vigor traits, along with the alteration in the metabolic profile. The investigations were conducted using a factorial experiment, including stress (deterioration and non-deterioration of seed) and cis-cinnamic acid pretreatment (0, 30, and 50 μM). Results showed that CA improved germination (25.5% to 50.8%) and seedling vigor (> 100%) in both cultivars, particularly under deterioration. Metabolomic profiling revealed that, in the untreated seeds of the more sensitive cultivar (Punjab), there was intense activation of glycolysis, the citric acid cycle, arginine-proline and glycine-serine metabolism pathways, together with the activity of the ammonia recycling pathway, representing an emergency attempt to compensate for impaired cellular energy availability, along with detoxification of harmful nitrogenous compounds. Conversely, CA pre-treatment led to the repression of costly metabolic pathways and the activation of the pentose phosphate pathway. The more tolerant cultivar (Varamin) displayed a coordinated metabolic adjustment to seed deterioration, involving integrated carbon-nitrogen metabolism and sustained redox homeostasis. CA pre-treatment further reinforced this intrinsic metabolic configuration by enhancing antioxidant defenses, improving nitrogen flux efficiency, and maintaining phenolic metabolism, thereby increasing reductive capacity and supporting metabolic homeostasis. Consequently, seed priming with CA can be recommended as an evidence-based, reliable management strategy to enhance seed physiological quality, mitigate deterioration-related losses, and ensure successful seedling establishment under field conditions.