Alleviation of postharvest chilling injury in anthurium cut flowers by salicylic acid treatment

Abstract

Due to the sensitivity of anthurium flowers to chilling injury, its optimum temperature storage is 12.5–20°C. Reactive oxygen species (ROS) accumulation during postharvest chilling stress leads to loss of membrane integrity which can be coincided with phenols oxidation by polyphenol oxidase (PPO) activity, the enzyme responsible for browning. Higher phenylalanine ammonia-lyase (PAL) activity, the enzyme responsible for phenols accumulation, under chilling stress, can act as a defense mechanism overcome chilling stress. In this experiment, the impact of 0, 1, 2 and 4mM salicylic acid (SA) treatment applied by postharvest stem-end dipping (15min at 20°C) on chilling injury of Anthurium andraeanum cv. Sirion cut flowers storage at 4°C for 21 days were investigated. SA treatment delayed spathe browning and retards electrolyte leakage and malondialdehyde (MDA) increase. The SA treated anthurium cut flowers exhibited significantly higher PAL enzyme activity, associated with lower PPO activity, which were coincided with higher total phenol accumulation and higher DPPH scavenging activity during storage at 4°C for 21 days. Also, higher DPPH scavenging activity in anthurium cut flowers treated with SA can be results from higher antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR) activity. Also, SA treatment enhanced endogenous proline and glycine betaine (GB) accumulation in anthurium cut flowers during storage at 4°C, which was coincided with higher spathe relative water content (RWC). These results suggested that SA treatment can be used as a useful technology for the alleviation of postharvest chilling injury in anthurium cut flowers by enhancing total phenol, proline, and GB accumulation coincide with enhancing antioxidant system activity leading to higher membrane integrity showed by lower electrolyte leakage and MDA content.