Effects of exogenous nitric oxide on lignification and anti-oxidation activity of postharvest green asparagus

In order to elucidate the adjustment mechanism of nitric oxide(NO) on the lignification of postharvest green asparagus, using sodium nitroprusside(SNP) of 0.2 mmol/L as a nitric oxide donor, and green asparagus treated with distilled water as controls, the paper investigated the effects of nitric oxide treatment on total phenol and lignin content, the relevant enzymes of lignin synthesis including PAL, CAD, PPO and POD, the anti-oxidation activity including the DPPH radical scavenging activity, and the superoxide radical scavenging activity and hydroxyl radical scavenging activity and membrane permeability. The result showed that NO treatment could delay the increase of lignin content and membrane permeability, inhibit the activities of CAD and PPO, increase the anti-oxidation activity, induce a significant increase in POD activity. However, there was no significant effect on PAL activity and total phenol content compared to control. This proved that NO treatment can delay the lignification of postharvest green asparagus through inhibiting the acitivities of CAD and PPO and increasing the anti-oxidation activity. The results can provide a theoretical basis and technical method for application of NO in green asparagus storage.