Low temperature conditioning and nitric oxide treatment reduced chilling injury and altered fatty acid metabolism of flat peaches

Low-temperature conditioning is a recognized method for alleviating chilling injuries in flat peaches. However, long-term low-temperature storage can mitigate volatile organic compounds, thereby limiting fruit availability. To improve the supply of flat peaches, we investigated the combined effects of low-temperature conditioning and nitric oxide treatment on various parameters including physiological quality, volatile organic compounds, fatty acids, associated enzymes, and genes involved in the fatty acid pathway with the transcriptome sequencing analysis. The results indicated that low-temperature conditioning coordinated with 10 µL L⁻¹ nitric oxide treatment possessed higher firmness and vitamin C content and restricted the content of malonaldehyde and relative electrical conductivity, thus maintaining the overall quality of flat peaches. In the study, 10 µL L⁻¹ nitric oxide was employed for subsequent experiments. Moreover, higher contents of volatile organic compounds were supported by increased contents of palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, alcohol dehydrogenase, hydroperoxide lyase, and up-regulated genes of LOX2, LOX3, LOX6, ADH2, and ADH3. In summary, nitric oxide treatment effectively facilitated the recovery of volatile organic compounds in flat peaches during cold storage. Therefore, low-temperature conditioning and nitric oxide treatment can be a promising strategy to prevent the loss of volatile organic compounds by modulating the fatty acid pathway and associated genes.