Inhibitory effect and mechanism of nitric oxide (NO) fumigation on fungal disease in Xinjiang Saimaiti dried apricots

• Published in: Food science & technology Vol. 116; p. 108507
• Main Authors: Chen, Yan, Guo, Qin, Wei, Jia, Zhang, Jian, Zhang, Zheng, Wang, Ji-de, Wu, Bin
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2019
• Subjects: Dried apricots; Fungal disease; Inhibitory effect; Nitric oxide (NO); Dried apricots; Nitric oxide (NO); Inhibitory effect; Fungal disease
• ISSN: 0023-6438; 1096-1127
• DOI: 10.1016/j.lwt.2019.108507

Nitric oxide (NO) is a gaseous free radical molecule that is widely used for controlling postharvest diseases in fresh fruit. However, there have been few reports on its application in dried fruit. In this study, the inhibitory effect of NO on disease in dried apricots caused by Aspergillus flavus, Aspergillus niger and Penicillium italicum was investigated both in vivo and in vitro. Furthermore, the inhibitory effect of NO and sulfur dioxide (SO2) on the three fungi was compared in vitro. NO fumigation decreased the severity of disease in dried apricots in vivo and suppressed colony expansion and mycelial growth of the three fungi in vitro in a concentration-dependent manner. The antifungal activity of NO was similar or better than that of SO2in vitro. Further, Mechanistic studies showed that NO reduced mycelium biomass, increased cell membrane permeability, destroyed plasma membrane integrity, and changed the mycelium microscopic structure. The damage of the fungal cell membrane induced by NO fumigation inhibited fungal growth and reproduction. Our results demonstrate that NO plays a critical role in controlling fungal disease in Xinjiang Saimaiti dried apricots. Aspergillus and Penicillium are major pathogenic fungi that cause disease in dried apricots leading to economic loss. Nitric oxide (NO) not only significantly reduces the severity of disease in dried apricots caused by Aspergillus flavus, Aspergillus niger and Penicillium italicum infection, but also strongly inhibits the growth and reproduction of these fungi isolated from naturally decayed dried apricots. This study found that NO negatively impacts the permeability and integrity of the fungal cell membrane, causes leakage of metal ions and nuclear contents. Furthermore, NO changes the morphology and causes severe deformation of the mycelium. Finally, NO inhibits the growth of fungi, and better controls the occurrence of dried apricot fungal diseases than current methods. [Display omitted] •Nitric oxide (NO) efficiently inhibited fungal diseases in dried apricots in vitro and in vivo.•NO exhibited a stronger antifungal effect than sulfur dioxide (SO2).•Fungi were inhibited by mycelia restraint, as well as membrane and microstructure damage.•NO is a potential fumigant for dried fruits.