Exogenous IAA delays leaf yellowing and preserves the quality of celery during postharvest storage

Celery is susceptible to losing market value due to its short shelf life, which is driven by leaf yellowing, nutrient loss, and aroma alteration during postharvest storage. Indole-3-acetic acid (IAA) has been reported to preserve quality in several fruits and vegetables, but its effect on celery remains unclear. In this study, celery was treated with IAA and its inhibitors p -phenoxyphenyl boronic acid (PPBo) and N-1-naphthylphthalamic acid (NPA) after harvest and then stored in black polyvinyl chloride bags at 20 °C and 80% relative humidity in the dark for 4 d, after which physiological quality indices, endogenous hormones, e-nose response profiles, and transcriptomic and metabolomic changes were analyzed. Treatment with 200 μM IAA showed the strongest effect by delaying yellowing and preserving the nutritional indices and limiting changes in the e-nose response profile. In contrast, PPBo and NPA inhibited endogenous IAA accumulation and accelerated senescence. Integrated metabolomic and transcriptomic analysis revealed that IAA influenced Calvin-cycle carbon fixation, glyoxylate and dicarboxylate metabolism, glycine/serine/threonine metabolism, and porphyrin metabolism. These findings indicate that exogenous IAA application prolongs the shelf life of celery.