Effect of Nitric Oxide on Antioxidative Response and Proline Metabolism in Banana during Cold Storage

Abstract

The effect of exogenous nitric oxide (NO) on chilling injury to banana fruit was investigated. Banana fruit was treated with NO donor sodium nitroprusside of 0.05 mM at 20 °C for 10 min and then stored at 7 °C for up to 20 days. Banana fruit treated with NO sustained a lower chilling injury index and higher firmness and kept lower electrolyte leakage and malondialdehyde content than the control. Further investigation showed that NO treatment enhanced activities of guaiacol peroxidase, ascorbate peroxidase, and glutathione reductase compared to the control. It also maintained higher ascorbic acid, reduced glutathione content, and total antioxidant capacity but reduced hydrogen peroxide and superoxide anion to lower levels compared to control fruit during storage. NO treatment significantly enhanced the accumulation of total phenolics and proline, which resulted from the increased activities of phenylalanine ammonia-lyase and Δ¹-pyrroline-5-carboxylate synthetase and decreased proline dehydrogenase activity. We proposed that the enhanced chilling tolerance induced by NO treatment may result from the reduction of oxidative stress and proline accumulation.

Mitigation of sodium chloride toxicity inSolanum lycopersicumL. by supplementation of jasmonic acid and nitric oxide

“…Enhancement in the accumulation of proline in JA-and NO-treated plants might have been due to an increased expression of its biosynthesizing genes. Proline accumulation under stressed conditions results from changes in the activities of proline synthesizing and degrading enzymes (Ahmad et al 2010) and the up-and down-regulation of genes (P5CS1, ProDH) responsible for proline biosynthesis (Wang et al 2013;Ahmad, Abdel Latef, et al 2016). Both proline and GB are involved in the regulation of osmotic balance, ensuring that the damages caused by stress can be overcome (Ahmad, Abdel Latef, et al 2016).…”

Hydrogen sulfide alleviates chilling injury of banana fruit by enhanced antioxidant system and proline content

“…The decrease of absorbance at 240 nm was measured and enzyme activity unit was calculated with extinction coefficient 40 mM -1 /cm. For APX and GR activity analysis, methods were according to Wang et al (2013).…”

“…The supernatant was used for measuring activities of PAL and POD. Methods were previously described by Wang et al (2013). For PPO activity determination, peel tissues were extracted with 50 mM PBS (pH 7.8).…”

NO to drought-multifunctional role of nitric oxide in plant drought: Do we have all the answers?

“…While its involvement in stress physiology is still unresolved, it has been suggested to enhance drought stress tolerance by protecting the protein turnover machinery from stress damage [12,15,73]. Proline has been shown to protect nitrogenase activity from water deficit stress in Glycine max [74].…”