Transcriptome and methylome analyses unveil the effects of low and high temperatures on the postharvest senescence of plum fruit

Abstract

Temperature strongly affects plum fruit senescence, but the epigenetic mechanism is unclear. Analysis of data on firmness, weigh loss rate, and decay rate showed that high temperature (HT) accelerates postharvest senescence, while low temperature (LT) delays it. Transcriptome analysis suggests that genes related to cell wall metabolism are associated with fruit softening. DNA methylation analysis shows that HT promotes fruit senescence accompanied by an increase in DNA methylation level, while LT delays senescence accompanied by a decrease in DNA methylation level. Further analysis suggests that PsDRM2 and PsDML1 may be responsible for regulating changes in methylation level. Association analysis showed that HT accelerates senescence through DNA methylation-mediated regulation of flavonoid metabolism, whereas LT delays senescence through DNA methylation-mediated regulation of lipid metabolism. These findings highlight the importance of temperature and DNA methylation in controlling postharvest senescence and provide valuable insights for developing effective strategies to control fruit senescence.