Effects of Exogenous Application of the Strigolactone GR24 on Quality and Flavor Components During Postharvest Storage of Celery

Celery is one of the mainly consumed leafy vegetables worldwide, however, its short postharvest freshness severely limits its storage and marketing. Studying the post-harvest biology and preservation techniques is important for storing celery products. This study investigated the effect of exogenous GR24 on the quality and flavor of celery during post-harvest storage. The results showed that GR24 can extend the storage life, reduce the decay and chlorophyll degradation, maintain the integrity of petiole cell morphology, and effectively maintain the contents of soluble protein, total phenols, Vc, and DPPH radical scavenging. The HS-SPME-GC/MS results showed that GR24 effectively maintained the levels of flavor compounds, especially D-Limonene, beta-Pinene, betaselinene, caryophyllene, and trans-beta-Ocimene, which contribute to the special flavor of celery. Moreover, the application of an exogenous 2.0 mu M GR24 solution resulted in elevated gene expression levels of AgGGPPS and AgTPS in the terpenoid pathway, thereby preserving the terpenoid content of D-Limonene, Terpinolene, and alpha-Copaene throughout the storage period. Consequently, spraying 2.0 mu M GR24 was the most effective concentration for maintaining the sensory quality, nutritional quality, and flavor of celery during storage.