Increasing Celery Resistance to Pathogens during Storage and Reducing High-risk Psoralen Concentration by Treatment with GA3

Abstract

Since psoralens have a very weak antifungal activity in vitro, we propose that (+)marmesin, the precursor of psoralens in celery (Apium graveolens L.) is associated with celery resistance to pathogens. (+)Marmesin has at least 100 times greater antifungal activity in vitro than psoralens. After 1 month of storage at 2C, the concentration of total psoralens increased from 8 to 67 μg·g-1 fresh weight, (+)marmesin decreased from 27 to 4 μg·g-1 fresh weight, and the incidence of decay increased from 0% to 34%. However, when celery was treated with GA3before 1 month of storage at 2C, decay increased to only 7%, the concentration of psoralens increased to 31 μg·g-1 fresh weight and the concentration of (+)marmesin decreased to 13 μg·g-1 fresh weight It seems that GA3 retarded celery decay during storage by slowing down the conversion of (+)marmesin to psoralens, thereby increasing the resistance to pathogens during storage.